The Efficacy of PCI's "Reading Program--Level One": A Report of a Randomized Experiment in Brevard Public Schools and Miami-Dade County Public Schools. Research Report

ERIC Educational Resources Information Center

Toby, Megan; Ma, Boya; Jaciw, Andrew; Cabalo, Jessica

2008-01-01

PCI Education sought scientifically based evidence on the effectiveness of the "PCI Reading Program--Level One" for students with severe disabilities. During the 2007-2008 academic year. Empirical Education conducted a randomized control trial (RCT) in two Florida districts, Brevard and Miami-Dade County Public Schools. For this…

The Efficacy of PCI's Reading Program--Level One: A Report of a Randomized Experiment in Brevard Public Schools and Miami-Dade County Public Schools. Research Summary

ERIC Educational Resources Information Center

Empirical Education Inc., 2008

2008-01-01

PCI Education sought scientifically based evidence on the effectiveness of the "PCI Reading Program--Level One" for students with severe disabilities. During the 2007-2008 academic year. Empirical Education conducted a randomized control trial (RCT) in two Florida districts, Brevard and Miami-Dade County Public Schools. For this…

Empirical Approaches to the Birthday Problem

ERIC Educational Resources Information Center

Flores, Alfinio; Cauto, Kevin M.

2012-01-01

This article will describe two activities in which students conduct experiments with random numbers so they can see that having at least one repeated birthday in a group of 40 is not unusual. The first empirical approach was conducted by author Cauto in a secondary school methods course. The second empirical approach was used by author Flores with…

Persistence of Learning Gains from Computer Assisted Learning: Experimental Evidence from China

ERIC Educational Resources Information Center

Mo, D.; Zhang, L.; Wang, J.; Huang, W.; Shi, Y.; Boswell, M.; Rozelle, S.

2015-01-01

Computer assisted learning (CAL) programs have been shown to be effective in improving educational outcomes. However, the existing studies on CAL have almost all been conducted over a short period of time. There is very little evidence on how the impact evolves over time. In response, we conducted a clustered randomized experiment involving 2741…

Getting Ahead: A Survey of Low-Wage Workers on Opportunities for Advancement.

ERIC Educational Resources Information Center

Lake Snell Perry & Associates, Inc., Washington, DC.

A nationwide sample of low-wage workers was conducted to ascertain their attitudes and experience regarding opportunities for advancement. Professional interviewers conducted telephone interviews with a random sample of 1,002 adults who work outside the home at least 30 hours per week and earn up to 200% of the federal poverty level. The…

Fluid Physics in a Fluctuating Acceleration Environment

NASA Technical Reports Server (NTRS)

Thomson, J. Ross; Drolet, Francois; Vinals, Jorge

1996-01-01

We summarize several aspects of an ongoing investigation of the effects that stochastic residual accelerations (g-jitter) onboard spacecraft can have on experiments conducted in a microgravity environment. The residual acceleration field is modeled as a narrow band noise, characterized by three independent parameters: intensity (g(exp 2)), dominant angular frequency Omega, and characteristic correlation time tau. Realistic values for these parameters are obtained from an analysis of acceleration data corresponding to the SL-J mission, as recorded by the SAMS instruments. We then use the model to address the random motion of a solid particle suspended in an incompressible fluid subjected to such random accelerations. As an extension, the effect of jitter on coarsening of a solid-liquid mixture is briefly discussed, and corrections to diffusion controlled coarsening evaluated. We conclude that jitter will not be significant in the experiment 'Coarsening of solid-liquid mixtures' to be conducted in microgravity. Finally, modifications to the location of onset of instability in systems driven by a random force are discussed by extending the standard reduction to the center manifold to the stochastic case. Results pertaining to time-modulated oscillatory convection are briefly discussed.

General Population Norms about Child Abuse and Neglect and Associations with Childhood Experiences

ERIC Educational Resources Information Center

Bensley, L.; Ruggles, D.; Simmons, K.W.; Harris, C.; Williams, K.; Putvin, T.; Allen, M.

2004-01-01

Background:: A variety of definitions of child abuse and neglect exist. However, little is known about norms in the general population as to what constitutes child abuse and neglect or how perceived norms may be related to personal experiences. Methods:: We conducted a random-digit-dialed telephone survey of 504 Washington State adults.…

Effect of fungicides on sorghum anthracnose and grain mold in Burleson County, Texas, 2013

USDA-ARS?s Scientific Manuscript database

The experiment was conducted at the Texas AgriLife Experiment Station near College Station. The hybrids BH3822 and BH 5566 were planted in replicated plots and treatment arranged in a randomized, blocked factorial design. Each replicate consisted of four, 20 ft rows, with 30-in. row spacing and a ...

Increasing Performance by Differentiated Teaching? Experimental Evidence of the Student Benefits of Digital Differentiation

ERIC Educational Resources Information Center

Haelermans, Carla; Ghysels, Joris; Prince, Fernao

2015-01-01

This paper explores the effect of digital differentiation on student performance using a randomized experiment. The experiment is conducted in a second year biology class among 115 prevocational students in the Netherlands. Differentiation allowed students in the treatment group to work at three different levels. The results show that there is a…

Using Norm-Based Appeals to Increase Response Rates in Evaluation Research: A Field Experiment

ERIC Educational Resources Information Center

Misra, Shalini; Stokols, Daniel; Marino, Anne Heberger

2012-01-01

A field experiment was conducted to test the effectiveness of norm-based persuasive messages for increasing response rates in online survey research. Participants in an interdisciplinary conference were asked to complete two successive postconference surveys and randomly assigned to one of two groups at each time point. The experimental group…

Effect of fungicides on sorghum anthracnose and grain mold in Burleson County, Texas, 2014

USDA-ARS?s Scientific Manuscript database

The experiment was conducted at the Texas A&M AgriLife Experiment Station near College Station (Burleson County), using the hybrids BH3822 and BH 5566. The seed was planted 10 Apr in a Belk clay soil. There were four replicates per treatment arranged in a randomized, blocked factorial design. Tre...

A Laboratory Experiment, Based on the Maillard Reaction, Conducted as a Project in Introductory Statistics

ERIC Educational Resources Information Center

Kravchuk, Olena; Elliott, Antony; Bhandari, Bhesh

2005-01-01

A simple laboratory experiment, based on the Maillard reaction, served as a project in Introductory Statistics for undergraduates in Food Science and Technology. By using the principles of randomization and replication and reflecting on the sources of variation in the experimental data, students reinforced the statistical concepts and techniques…

Women Students at Coeducational and Women's Colleges: How Do Their Experiences Compare?

ERIC Educational Resources Information Center

Kinzie, Jillian L.; Thomas, Auden D.; Palmer, Megan M.; Umbach, Paul D.; Kuh, George D.

2007-01-01

This study compared the experiences of women attending women's colleges with those of women attending coeducational institutions. Analyses of data from the National Survey of Student Engagement (NSSE) from random samples of female first-year and senior students from 26 women's colleges and 264 other four-year institutions were conducted. Women at…

Recruitment experience for a pragmatic randomized controlled trial: Using EMR initiatives and minimizing research infrastructure.

PubMed

Joseph, Christine Lm; Ownby, Dennis R; Zoratti, Edward; Johnson, Dayna; Considine, Shannon; Bourgeois, Renee; Melkonian, Christina; Miree, Cheryl; Johnson, Christine Cole; Lu, Mei

2016-01-01

Modernized approaches to multisite randomized controlled trials (RCT) include the use of electronic medical records (EMR) for recruitment, remote data capture (RDC) for multisite data collection, and strategies to reduce the need for research infrastructure. These features facilitate the conduct of pragmatic trials, or trials conducted in "real life" settings. We describe the recruitment experience of an RCT to evaluate a clinic-based intervention targeting urban youth with asthma. Using encounter and prescription databases, a list of potentially-eligible patients was linked to the Epic appointment scheduling system. Patients were enrolled during a scheduled visit and then electronically randomized to a tailored versus generic online intervention. 1146 appointments for 580 eligible patients visiting 5 clinics were identified, of which 45.9% (266/580) were randomized to reach targeted enrollment (n=250). RDC facilitated multisite enrollment. Intervention content was further personalized through real- time entry of asthma medications prescribed at the clinic visit. EMR monitoring helped with recruitment trouble-shooting. Systemic challenges included a system-wide EMR transition and a system-wide reorganization of clinic staffing. Modernized RCTs can accelerate translation of research findings. Electronic initiatives facilitated implementation of this RCT; however, adaptations to recruitment strategies resulted in a more "explanatory" framework. .

Women's experiences as members of attention control and experimental intervention groups in a randomized controlled trial.

PubMed

Beal, Claudia C; Stuifbergen, Alexa; Volker, Deborah; Becker, Heather

2009-12-01

Attention control groups are often used in research testing the efficacy of psychosocial and behavioural interventions in order to control for placebo effects. The authors conducted a descriptive qualitative study to investigate how participants viewed their experiences in attention control and experimental intervention groups following a randomized controlled trial for women with fibromyalgia syndrome. Moderately structured interviews were conducted with 18 women (12 from the experimental intervention group and 6 from the attention control group). Members of the control group reported some benefits but few behavioural changes as a result of participating in the RCT, and some participants expressed disappointment at not receiving the intervention. Perceptions of changes in attitudes towards fibromyalgia syndrome and behaviours reported by the intervention group appear to be consistent with the theory underlying the intervention. Possible placebo effects identified in both groups include negative and positive social interactions with other participants.

Lidar transmitter offers "non-diffracting" property through short distance in highly-dense random media

NASA Astrophysics Data System (ADS)

Alifu, Xiafukaiti; Ziqi, Peng; Shiina, Tatsuo

2018-04-01

Non-diffracting beam (NDB) is useful in lidar transmitter because of its high propagation efficiency and high resolution. We aimed to generate NDB in random media such as haze and cloud. The laboratory experiment was conducted with diluted processed milk (fat: 1.8%, 1.1μmφ). Narrow view angle detector of 5.5mrad was used to detect the forward scattering waveform. We obtained the central peak of NDB at the propagation distance of 5cm 30cm in random media by adjusting the concentration of <10%.

A system identification technique based on the random decrement signatures. Part 2: Experimental results

NASA Technical Reports Server (NTRS)

Bedewi, Nabih E.; Yang, Jackson C. S.

1987-01-01

Identification of the system parameters of a randomly excited structure may be treated using a variety of statistical techniques. Of all these techniques, the Random Decrement is unique in that it provides the homogeneous component of the system response. Using this quality, a system identification technique was developed based on a least-squares fit of the signatures to estimate the mass, damping, and stiffness matrices of a linear randomly excited system. The results of an experiment conducted on an offshore platform scale model to verify the validity of the technique and to demonstrate its application in damage detection are presented.

Remedying Education: Evidence from Two Randomized Experiments in India. NBER Working Paper No. 11904

ERIC Educational Resources Information Center

Banerjee, Abhijit; Cole, Shawn; Duflo, Esther; Linden, Leigh

2005-01-01

Many efforts to improve school quality by adding school resources have proven to be ineffective. This paper presents the results of two experiments conducted in Mumbai and Vadodara, India, designed to evaluate ways to improve the quality of education in urban slums. A remedial education program hired young women from the community to teach basic…

Promoting the Positive Development of Boys in High-Poverty Neighborhoods: Evidence from Four Anti-Poverty Experiments

ERIC Educational Resources Information Center

Snell, Emily K.; Castells, Nina; Duncan, Greg; Gennetian, Lisa; Magnuson, Katherine; Morris, Pamela

2013-01-01

This study uses geocoded address data and information about parents' economic behavior and children's development from four random-assignment welfare and anti-poverty experiments conducted during the 1990s. We find that the impacts of these welfare and anti-poverty programs on boys' and girls' developmental outcomes during the transition to early…

The Quality Improvement Demonstration Study: An example of evidence-based policy-making in practice

PubMed Central

Shimkhada, Riti; Peabody, John W; Quimbo, Stella A; Solon, Orville

2008-01-01

Background Randomized trials have long been the gold-standard for evaluating clinical practice. There is growing recognition that rigorous studies are similarly needed to assess the effects of policy. However, these studies are rarely conducted. We report on the Quality Improvement Demonstration Study (QIDS), an example of a large randomized policy experiment, introduced and conducted in a scientific manner to evaluate the impact of large-scale governmental policy interventions. Methods In 1999 the Philippine government proposed sweeping reforms in the National Health Sector Reform Agenda. We recognized the unique opportunity to conduct a social experiment. Our ongoing goal has been to generate results that inform health policy. Early on we concentrated on developing a multi-institutional collaborative effort. The QIDS team then developed hypotheses that specifically evaluated the impact of two policy reforms on both the delivery of care and long-term health status in children. We formed an experimental design by randomizing matched blocks of three communities into one of the two policy interventions plus a control group. Based on the reform agenda, one arm of the experiment provided expanded insurance coverage for children; the other introduced performance-based payments to hospitals and physicians. Data were collected in household, hospital-based patient exit, and facility surveys, as well as clinical vignettes, which were used to assess physician practice. Delivery of services and health status were evaluated at baseline and after the interventions were put in place using difference-in-difference estimation. Results We found and addressed numerous challenges conducting this study, namely: formalizing the experimental design using the existing health infrastructure; securing funding to do research coincident with the policy reforms; recognizing biases and designing the study to account for these; putting in place a broad data collection effort to account for unanticipated findings; introducing sustainable policy interventions based on the reform agenda; and providing results in real-time to policy makers through a combination of venues. Conclusion QIDS demonstrates that a large, prospective, randomized controlled policy experiment can be successfully implemented at a national level as part of sectoral reform. While we believe policy experiments should be used to generate evidence-based health policy, to do this requires opportunity and trust, strong collaborative relationships, and timing. This study nurtures the growing attitude that translation of scientific findings from the bedside to the community can be done successfully and that we should raise the bar on project evaluation and the policy-making process. PMID:18364050

Microgravity simulations with human lymphocytes in the free fall machine and in the random positioning machine

NASA Technical Reports Server (NTRS)

Schwarzenberg, M.; Pippia, P.; Meloni, M. A.; Cossu, G.; Cogoli-Greuter, M.; Cogoli, A.

1998-01-01

The purpose of this paper is to present the results obtained in our laboratory with both instruments, the FFM [free fall machine] and the RPM [random positioning machine], to compare them with the data from earlier experiments with human lymphocytes conducted in the FRC [fast rotating clinostat] and in space. Furthermore, the suitability of the FFM and RPM for research in gravitational cell biology is discussed.

The Use and Misuse of Computers in Education: Evidence from a Randomized Experiment in Colombia. Impact Evaluation Series No. 29. Policy Research Working Paper 4836

ERIC Educational Resources Information Center

Barrera-Osorio, Felipe; Linden, Leigh L.

2009-01-01

This paper presents the evaluation of the program Computers for Education. The program aims to integrate computers, donated by the private sector, into the teaching of language in public schools. The authors conduct a two-year randomized evaluation of the program using a sample of 97 schools and 5,201 children. Overall, the program seems to have…

Ground vibration test of the laminar flow control JStar airplane

NASA Technical Reports Server (NTRS)

Kehoe, M. W.; Cazier, F. W., Jr.; Ellison, J. F.

1985-01-01

A ground vibration test was conducted on a Lockheed JetStar airplane that had been modified for the purpose of conducting laminar flow control experiments. The test was performed prior to initial flight flutter tests. Both sine-dwell and single-point-random excitation methods were used. The data presented include frequency response functions and a comparison of mode frequencies and mode shapes from both methods.

Nonlocal Intuition: Replication and Paired-subjects Enhancement Effects

PubMed Central

Mirzaei, Maryam; Zali, Mohammad Reza

2014-01-01

This article reports the results of a study of repeat entrepreneurs in Tehran, Iran, in which nonlocal intuition was investigated in a replication and extension of experiment using measures of heart rate variability (HRV). Nonlocal intuition is the perception of information about a distant or future event by the body's psychophysiological systems, which is not based on reason or memories of prior experience. This study follows up on the McCraty, Radin, and Bradley studies, which found evidence of nonlocal intuition. We used Radin's experimental protocol, with the addition of HRV measures as in the McCraty studies involving computer administration of a random sequence of calm and emotional pictures as the stimulus, and conducted two experiments on mutually exclusive samples—the first on a group of single participants (N=15) and the second on a group of co-participant pairs (N=30)—to investigate the question of the “amplification” of intuition effects by social connection. Each experiment was conducted over 45 trials while heart rate rhythm activity was recorded continuously. Results, using random permutation analysis, a statistically conservative procedure, show significant pre-stimulus results—that is, for the period before the computer had randomly selected the picture stimulus—for both experiments. Moreover, while significant separation between the emotional and calm HRV curves was observed in the single-participant experiment, an even larger separation was apparent for the experiment on co-participant pairs; the difference between the two groups was also significant. Overall, the results of the single-participant experiment confirm previous finding: that electrophysiological measures, especially changes in the heart rhythm, can detect intuitive foreknowledge. This result is notable because it constitutes cross-cultural corroboration in a non-Western context—namely, Iran. In addition, the results for co-participant pairs offer new evidence on the amplification of the nonlocal intuition signal. PMID:24808977

Effects of Interim Assessments on Student Achievement: Evidence from a Large-Scale Experiment

ERIC Educational Resources Information Center

Konstantopoulos, Spyros; Miller, Shazia R.; van der Ploeg, Arie; Li, Wei

2016-01-01

We use data from a large-scale, school-level randomized experiment conducted in 2010-2011 in public schools in Indiana. Our sample includes more than 30,000 students in 70 schools. We examine the impact of two interim assessment programs (i.e., mCLASS in Grades K-2 and Acuity in Grades 3--8) on mathematics and reading achievement. Two-level models…

Microwave scattering models and basic experiments

NASA Technical Reports Server (NTRS)

Fung, Adrian K.

1989-01-01

Progress is summarized which has been made in four areas of study: (1) scattering model development for sparsely populated media, such as a forested area; (2) scattering model development for dense media, such as a sea ice medium or a snow covered terrain; (3) model development for randomly rough surfaces; and (4) design and conduct of basic scattering and attenuation experiments suitable for the verification of theoretical models.

Examining Teachers' Attitudes and Experiences with Coaching to Inform Research-Based Practice: An Iterative Developmental Design Study

ERIC Educational Resources Information Center

Shernoff, Elisa S.; Lekwa, Adam J.; Reddy, Linda A.; Coccaro, Candace

2017-01-01

The purpose of this qualitative study was to examine teachers' attitudes and experiences with coaching. This study was conducted in advance of a planned randomized controlled trial of a coaching intervention to better align the model with teachers' needs and goals. Thirty-four K-5 general (n = 26), special education (n = 6), and educational…

Lidar backscattering measurements of background stratospheric aerosols

NASA Technical Reports Server (NTRS)

Remsberg, E. E.; Northam, G. B.; Butler, C. F.

1979-01-01

A comparative lidar-dustsonde experiment was conducted in San Angelo, Texas, in May 1974 in order to estimate the uncertainties in stratospheric-aerosol backscatter for the NASA Langley 48-inch lidar system. The lidar calibration and data-analysis procedures are discussed. Results from the Texas experiment indicate random and systematic uncertainties of 35 and 63 percent, respectively, in backscatter from a background stratospheric-aerosol layer at 20 km.

Does Money Really Matter? Estimating Impacts of Family Income on Young Children's Achievement with Data from Random-Assignment Experiments

ERIC Educational Resources Information Center

Duncan, Greg J.; Morris, Pamela A.; Rodrigues, Chris

2011-01-01

Social scientists do not agree on the size and nature of the causal impacts of parental income on children's achievement. We revisit this issue using a set of welfare and antipoverty experiments conducted in the 1990s. We utilize an instrumental variables strategy to leverage the variation in income and achievement that arises from random…

A Practical Methodology for Quantifying Random and Systematic Components of Unexplained Variance in a Wind Tunnel

NASA Technical Reports Server (NTRS)

Deloach, Richard; Obara, Clifford J.; Goodman, Wesley L.

2012-01-01

This paper documents a check standard wind tunnel test conducted in the Langley 0.3-Meter Transonic Cryogenic Tunnel (0.3M TCT) that was designed and analyzed using the Modern Design of Experiments (MDOE). The test designed to partition the unexplained variance of typical wind tunnel data samples into two constituent components, one attributable to ordinary random error, and one attributable to systematic error induced by covariate effects. Covariate effects in wind tunnel testing are discussed, with examples. The impact of systematic (non-random) unexplained variance on the statistical independence of sequential measurements is reviewed. The corresponding correlation among experimental errors is discussed, as is the impact of such correlation on experimental results generally. The specific experiment documented herein was organized as a formal test for the presence of unexplained variance in representative samples of wind tunnel data, in order to quantify the frequency with which such systematic error was detected, and its magnitude relative to ordinary random error. Levels of systematic and random error reported here are representative of those quantified in other facilities, as cited in the references.

Control of the peachtree borer using beneficial nematodes

USDA-ARS?s Scientific Manuscript database

The peachtree borer, Synanthedon exitiosa, is a major pest of peaches and other stone fruits. Our research indicates that entomopathogenic nematodes, also known as beneficial nematodes, can be used effectively to control the insect. We conducted replicated experiments in randomized block designs ov...

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.

3D statistical shape models incorporating 3D random forest regression voting for robust CT liver segmentation

NASA Astrophysics Data System (ADS)

Norajitra, Tobias; Meinzer, Hans-Peter; Maier-Hein, Klaus H.

2015-03-01

During image segmentation, 3D Statistical Shape Models (SSM) usually conduct a limited search for target landmarks within one-dimensional search profiles perpendicular to the model surface. In addition, landmark appearance is modeled only locally based on linear profiles and weak learners, altogether leading to segmentation errors from landmark ambiguities and limited search coverage. We present a new method for 3D SSM segmentation based on 3D Random Forest Regression Voting. For each surface landmark, a Random Regression Forest is trained that learns a 3D spatial displacement function between the according reference landmark and a set of surrounding sample points, based on an infinite set of non-local randomized 3D Haar-like features. Landmark search is then conducted omni-directionally within 3D search spaces, where voxelwise forest predictions on landmark position contribute to a common voting map which reflects the overall position estimate. Segmentation experiments were conducted on a set of 45 CT volumes of the human liver, of which 40 images were randomly chosen for training and 5 for testing. Without parameter optimization, using a simple candidate selection and a single resolution approach, excellent results were achieved, while faster convergence and better concavity segmentation were observed, altogether underlining the potential of our approach in terms of increased robustness from distinct landmark detection and from better search coverage.

Effects of Welfare and Employment Policies on Young Children: New Findings on Policy Experiments Conducted in the Early 1990s. Social Policy Report. Volume 19, Number 2

ERIC Educational Resources Information Center

Morris, Pamela A.; Gennetian, Lisa A.; Duncan, Greg J.

2005-01-01

Over the past 30 years, welfare and other public programs for poor families have focused increasingly on promoting parents' self-sufficiency by requiring and supporting employment. Evidence from a diverse set of random-assignment experiments now reveals some of the conditions under which promoting work among low-income, single parents helps or…

Statistical modeling of software reliability

NASA Technical Reports Server (NTRS)

Miller, Douglas R.

1992-01-01

This working paper discusses the statistical simulation part of a controlled software development experiment being conducted under the direction of the System Validation Methods Branch, Information Systems Division, NASA Langley Research Center. The experiment uses guidance and control software (GCS) aboard a fictitious planetary landing spacecraft: real-time control software operating on a transient mission. Software execution is simulated to study the statistical aspects of reliability and other failure characteristics of the software during development, testing, and random usage. Quantification of software reliability is a major goal. Various reliability concepts are discussed. Experiments are described for performing simulations and collecting appropriate simulated software performance and failure data. This data is then used to make statistical inferences about the quality of the software development and verification processes as well as inferences about the reliability of software versions and reliability growth under random testing and debugging.

The Counseling Competencies Scale: Validation and Refinement

ERIC Educational Resources Information Center

Lambie, Glenn W.; Mullen, Patrick R.; Swank, Jacqueline M.; Blount, Ashley

2018-01-01

Supervisors evaluated counselors-in-training at multiple points during their practicum experience using the Counseling Competencies Scale (CCS; N = 1,070). The CCS evaluations were randomly split to conduct exploratory factor analysis and confirmatory factor analysis, resulting in a 2-factor model (61.5% of the variance explained).

Nonfumigant Alternatives to Methyl Bromide for Production of Snapdragon (Antirrhinum majus)

USDA-ARS?s Scientific Manuscript database

Two field experiments were conducted in north Florida to examine effects of solarization and reduced-risk pesticides on weeds, nematodes, soil-borne diseases, and yield of snapdragon (Antirrhinum majus). Five treatments were replicated five times in a randomized complete block design: fumigation wit...

78 FR 24423 - Submission for OMB Review; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-25

... an experimental research design. Program applicants who are eligible for CSPED services will be randomly assigned to either a program group that is offered program services or a control group that is not...) conducting focus groups with program participants to elicit participation experiences; (3) administering a...

Multi-Sensory Intervention Observational Research

ERIC Educational Resources Information Center

Thompson, Carla J.

2011-01-01

An observational research study based on sensory integration theory was conducted to examine the observed impact of student selected multi-sensory experiences within a multi-sensory intervention center relative to the sustained focus levels of students with special needs. A stratified random sample of 50 students with severe developmental…

Teacher Incentives in Developing Countries: Experimental Evidence from India. Research Brief

ERIC Educational Resources Information Center

National Center on Performance Incentives, 2008

2008-01-01

In "Teacher Incentives in Developing Countries: Experimental Evidence from India"--a paper presented at the National Center on Performance Incentives research to policy conference in February--Karthik Muralidharan (Harvard University) and Venkatesh Sundararaman (The World Bank) present findings from a randomized experiment conducted in…

Experiments on individual strategy updating in iterated snowdrift game under random rematching.

PubMed

Qi, Hang; Ma, Shoufeng; Jia, Ning; Wang, Guangchao

2015-03-07

How do people actually play the iterated snowdrift games, particularly under random rematching protocol is far from well explored. Two sets of laboratory experiments on snowdrift game were conducted to investigate human strategy updating rules. Four groups of subjects were modeled by experience-weighted attraction learning theory at individual-level. Three out of the four groups (75%) passed model validation. Substantial heterogeneity is observed among the players who update their strategies in four typical types, whereas rare people behave like belief-based learners even under fixed pairing. Most subjects (63.9%) adopt the reinforcement learning (or alike) rules; but, interestingly, the performance of averaged reinforcement learners suffered. It is observed that two factors seem to benefit players in competition, i.e., the sensitivity to their recent experiences and the overall consideration of forgone payoffs. Moreover, subjects with changing opponents tend to learn faster based on their own recent experience, and display more diverse strategy updating rules than they do with fixed opponent. These findings suggest that most of subjects do apply reinforcement learning alike updating rules even under random rematching, although these rules may not improve their performance. The findings help evolutionary biology researchers to understand sophisticated human behavioral strategies in social dilemmas. Copyright © 2015 Elsevier Ltd. All rights reserved.

Pilot study evaluating a brief mindfulness intervention for those with chronic pain: study protocol for a randomized controlled trial.

PubMed

Howarth, Ana; Perkins-Porras, Linda; Smith, Jared G; Subramaniam, Jeevakan; Copland, Claire; Hurley, Mike; Beith, Iain; Riaz, Muhammad; Ussher, Michael

2016-06-02

The burden of chronic pain is a major challenge, impacting the quality of life of patients. Intensive programmes of mindfulness-based therapy can help patients to cope with chronic pain but can be time consuming and require a trained specialist to implement. The self-management model of care is now integral to the care of patients with chronic pain; home-based interventions can be very acceptable, making a compelling argument for investigating brief, self-management interventions. The aim of this study is two-fold: to assess the immediate effects of a brief self-help mindfulness intervention for coping with chronic pain and to assess the feasibility of conducting a definitive randomized controlled trial to determine the effectiveness of such an intervention. A randomized controlled pilot study will be conducted to evaluate a brief mindfulness intervention for those with chronic pain. Ninety chronic pain patients who attend hospital outpatient clinics will be recruited and allocated randomly to either the control or treatment group on a 1:1 basis using the computer-generated list of random numbers. The treatment group receives mindfulness audios and the control group receives audios of readings from a non-fiction book, all of which are 15 minutes in length. Immediate effects of the intervention are assessed with brief psychological measures immediately before and after audio use. Mindfulness, mood, health-related quality of life, pain catastrophizing and experience of the intervention are assessed with standardized measures, brief ratings and brief telephone follow-ups, at baseline and after one week and one month. Feasibility is assessed by estimation of effect sizes for outcomes, patient adherence and experience, and appraisal of resource allocation in provision of the intervention. This trial will assess whether a brief mindfulness-based intervention is effective for immediately reducing perceived distress and pain with the side effect of increasing relaxation in chronic pain patients and will determine the feasibility of conducting a definitive randomized controlled trial. Patient recruitment began in January 2015 and is due to be completed in June 2016. ISRCTN61538090 Registered 20 April 2015.

Employment and Childcare Arrangements among Families.

ERIC Educational Resources Information Center

Podmore, Valerie N.

A study investigated parents' experiences and their views on labor force participation and childcare arrangements. An in-depth interview was conducted with the parent or parents from 60 families with 5-year-old children, selected randomly from 14 schools in the greater Wellington, New Zealand, region. Results included the following: (1) playgroups…

Within-Cluster and Across-Cluster Matching with Observational Multilevel Data

ERIC Educational Resources Information Center

Kim, Jee-Seon; Steiner, Peter M.; Hall, Courtney; Thoemmes, Felix

2013-01-01

When randomized experiments cannot be conducted in practice, propensity score (PS) techniques for matching treated and control units are frequently used for estimating causal treatment effects from observational data. Despite the popularity of PS techniques, they are not yet well studied for matching multilevel data where selection into treatment…

Disability Discrimination in Higher Education: Analyzing the Quality of Counseling Services

ERIC Educational Resources Information Center

Deuchert, Eva; Kauer, Lukas; Liebert, Helge; Wuppermann, Carl

2017-01-01

We conduct a field experiment to analyze barriers disabled students face when entering higher education institutions. Fictitious high-school graduates request information regarding the admission process and special accommodations to ease studying. Potential applicants randomly reveal one of four impairment types. Response rates are similar for all…

Shade, irrigation, and nutrients affect flavanoid concentration and yield in American Skullcap.

USDA-ARS?s Scientific Manuscript database

American skullcap (Scutellaria lateriflora L.) is valued for its sedative properties that are associated with flavonoids. Information on how growing conditions affect flavonoid content is lacking. A 2x2x3 factorial experiment was conducted in a randomized complete block design (r = 4) with a split ...

Effects of the Case-Based Instruction Method on the Experience of Learning

ERIC Educational Resources Information Center

Amiri Farahani, Leila; Heidari, Tooba

2014-01-01

This semi-experimental study was conducted with twenty-seven midwifery students who were randomly allocated to either case-based instruction or lecture-based instruction groups. The selected subjects -- foetal intrapartum assessment, foetal antepartum assessment, ABO and Rh blood group system mismatch -- were presented in four ninety-minute…

Does money really matter? Estimating impacts of family income on young children's achievement with data from random-assignment experiments.

PubMed

Duncan, Greg J; Morris, Pamela A; Rodrigues, Chris

2011-09-01

Social scientists do not agree on the size and nature of the causal impacts of parental income on children's achievement. We revisit this issue using a set of welfare and antipoverty experiments conducted in the 1990s. We utilize an instrumental variables strategy to leverage the variation in income and achievement that arises from random assignment to the treatment group to estimate the causal effect of income on child achievement. Our estimates suggest that a $1,000 increase in annual income increases young children's achievement by 5%-6% of a standard deviation. As such, our results suggest that family income has a policy-relevant, positive impact on the eventual school achievement of preschool children.

Analysis on pseudo excitation of random vibration for structure of time flight counter

NASA Astrophysics Data System (ADS)

Wu, Qiong; Li, Dapeng

2015-03-01

Traditional computing method is inefficient for getting key dynamical parameters of complicated structure. Pseudo Excitation Method(PEM) is an effective method for calculation of random vibration. Due to complicated and coupling random vibration in rocket or shuttle launching, the new staging white noise mathematical model is deduced according to the practical launch environment. This deduced model is applied for PEM to calculate the specific structure of Time of Flight Counter(ToFC). The responses of power spectral density and the relevant dynamic characteristic parameters of ToFC are obtained in terms of the flight acceptance test level. Considering stiffness of fixture structure, the random vibration experiments are conducted in three directions to compare with the revised PEM. The experimental results show the structure can bear the random vibration caused by launch without any damage and key dynamical parameters of ToFC are obtained. The revised PEM is similar with random vibration experiment in dynamical parameters and responses are proved by comparative results. The maximum error is within 9%. The reasons of errors are analyzed to improve reliability of calculation. This research provides an effective method for solutions of computing dynamical characteristic parameters of complicated structure in the process of rocket or shuttle launching.

Dynamical conductivity at the dirty superconductor-metal quantum phase transition.

PubMed

Del Maestro, Adrian; Rosenow, Bernd; Hoyos, José A; Vojta, Thomas

2010-10-01

We study the transport properties of ultrathin disordered nanowires in the neighborhood of the superconductor-metal quantum phase transition. To this end we combine numerical calculations with analytical strong-disorder renormalization group results. The quantum critical conductivity at zero temperature diverges logarithmically as a function of frequency. In the metallic phase, it obeys activated scaling associated with an infinite-randomness quantum critical point. We extend the scaling theory to higher dimensions and discuss implications for experiments.

Experimental studies of two-stage centrifugal dust concentrator

NASA Astrophysics Data System (ADS)

Vechkanova, M. V.; Fadin, Yu M.; Ovsyannikov, Yu G.

2018-03-01

The article presents data of experimental results of two-stage centrifugal dust concentrator, describes its design, and shows the development of a method of engineering calculation and laboratory investigations. For the experiments, the authors used quartz, ceramic dust and slag. Experimental dispersion analysis of dust particles was obtained by sedimentation method. To build a mathematical model of the process, dust collection was built using central composite rotatable design of the four factorial experiment. A sequence of experiments was conducted in accordance with the table of random numbers. Conclusion were made.

Peer Assessment Enhances Student Learning: The Results of a Matched Randomized Crossover Experiment in a College Statistics Class.

PubMed

Sun, Dennis L; Harris, Naftali; Walther, Guenther; Baiocchi, Michael

2015-01-01

Feedback has a powerful influence on learning, but it is also expensive to provide. In large classes it may even be impossible for instructors to provide individualized feedback. Peer assessment is one way to provide personalized feedback that scales to large classes. Besides these obvious logistical benefits, it has been conjectured that students also learn from the practice of peer assessment. However, this has never been conclusively demonstrated. Using an online educational platform that we developed, we conducted an in-class matched-set, randomized crossover experiment with high power to detect small effects. We establish that peer assessment causes a small but significant gain in student achievement. Our study also demonstrates the potential of web-based platforms to facilitate the design of high-quality experiments to identify small effects that were previously not detectable.

Comparison of VLBI, TV and traveling clock techniques for time transfer

NASA Technical Reports Server (NTRS)

Spencer, J. H.; Waltman, E. B.; Johnston, K. J.; Santini, N. J.; Klepczynski, W. J.; Matsakis, D. N.; Angerhofer, P. E.; Kaplan, G. M.

1982-01-01

A three part experiment was conducted to develop and compare time transfer techniques. The experiment consisted of (1) a very long baseline interferometer (VLBI), (2) a high precision portable clock time transfer system between the two sites, and (3) a television time transfer. A comparison of the VLBI and traveling clock shows each technique can perform satisfactorily at the five nsec level. There was a systematic offset of 59 nsec between the two methods, which we attributed to a difference in epochs between VLBI formatter and station clock. The VLBI method had an internal random error of one nsec at the three sigma level for a two day period. Thus, the Mark II system performed well, and VLBI shows promise of being an accurate method of time transfer. The TV system, which had technical problems during the experiment, transferred time with a random error of about 50 nsec.

The Influence of Education and Experience Upon Contextual and Task Performance in Warehouse Operations

DTIC Science & Technology

2016-09-01

leadership. Subjects were randomly assigned to one of four groups to conduct a mixed- design experiment; the design included a 2 x 2 factorial component...The experimental design should have resulted in baseline groups that were representative of the target population; therefore, one would expect...1983; Sheridan, 2015). “SRK provides a language in which to talk about types of behavior as a basis for system design . It provides a basis on which

Cooperation and Contagion in Web-Based, Networked Public Goods Experiments

PubMed Central

Suri, Siddharth; Watts, Duncan J.

2011-01-01

A longstanding idea in the literature on human cooperation is that cooperation should be reinforced when conditional cooperators are more likely to interact. In the context of social networks, this idea implies that cooperation should fare better in highly clustered networks such as cliques than in networks with low clustering such as random networks. To test this hypothesis, we conducted a series of web-based experiments, in which 24 individuals played a local public goods game arranged on one of five network topologies that varied between disconnected cliques and a random regular graph. In contrast with previous theoretical work, we found that network topology had no significant effect on average contributions. This result implies either that individuals are not conditional cooperators, or else that cooperation does not benefit from positive reinforcement between connected neighbors. We then tested both of these possibilities in two subsequent series of experiments in which artificial seed players were introduced, making either full or zero contributions. First, we found that although players did generally behave like conditional cooperators, they were as likely to decrease their contributions in response to low contributing neighbors as they were to increase their contributions in response to high contributing neighbors. Second, we found that positive effects of cooperation were contagious only to direct neighbors in the network. In total we report on 113 human subjects experiments, highlighting the speed, flexibility, and cost-effectiveness of web-based experiments over those conducted in physical labs. PMID:21412431

Cooperation and contagion in web-based, networked public goods experiments.

PubMed

Suri, Siddharth; Watts, Duncan J

2011-03-11

A longstanding idea in the literature on human cooperation is that cooperation should be reinforced when conditional cooperators are more likely to interact. In the context of social networks, this idea implies that cooperation should fare better in highly clustered networks such as cliques than in networks with low clustering such as random networks. To test this hypothesis, we conducted a series of web-based experiments, in which 24 individuals played a local public goods game arranged on one of five network topologies that varied between disconnected cliques and a random regular graph. In contrast with previous theoretical work, we found that network topology had no significant effect on average contributions. This result implies either that individuals are not conditional cooperators, or else that cooperation does not benefit from positive reinforcement between connected neighbors. We then tested both of these possibilities in two subsequent series of experiments in which artificial seed players were introduced, making either full or zero contributions. First, we found that although players did generally behave like conditional cooperators, they were as likely to decrease their contributions in response to low contributing neighbors as they were to increase their contributions in response to high contributing neighbors. Second, we found that positive effects of cooperation were contagious only to direct neighbors in the network. In total we report on 113 human subjects experiments, highlighting the speed, flexibility, and cost-effectiveness of web-based experiments over those conducted in physical labs.

Vietnamese Amerasians: Practical Implications of Current Research.

ERIC Educational Resources Information Center

Felsman, J. Kirk.; And Others

This study was conducted to examine the experiences of Amerasians from Vietnam who resettled in the United States and to explore coping and adaptation among Vietnamese Amerasians over time. The initial data collection phase involved in-camp assessment of a randomly selected sample of Amerasian adolescents (N=259). The assessment is to be repeated…

Do Interim Assessments Reduce the Race and SES Achievement Gaps?

ERIC Educational Resources Information Center

Konstantopoulos, Spyros; Li, Wei; Miller, Shazia R.; van der Ploeg, Arie

2017-01-01

The authors examined differential effects of interim assessments on minority and low socioeconomic status students' achievement in Grades K-6. They conducted a large-scale cluster randomized experiment in 2009-2010 to evaluate the impact of Indiana's policy initiative introducing interim assessments statewide. The authors used 2-level models to…

Process and Learning Outcomes from Remotely-Operated, Simulated, and Hands-on Student Laboratories

ERIC Educational Resources Information Center

Corter, James E.; Esche, Sven K.; Chassapis, Constantin; Ma, Jing; Nickerson, Jeffrey V.

2011-01-01

A large-scale, multi-year, randomized study compared learning activities and outcomes for hands-on, remotely-operated, and simulation-based educational laboratories in an undergraduate engineering course. Students (N = 458) worked in small-group lab teams to perform two experiments involving stress on a cantilever beam. Each team conducted the…

(Pea)nuts and Bolts of Visual Narrative: Structure and Meaning in Sequential Image Comprehension

ERIC Educational Resources Information Center

Cohn, Neil; Paczynski, Martin; Jackendoff, Ray; Holcomb, Phillip J.; Kuperberg, Gina R.

2012-01-01

Just as syntax differentiates coherent sentences from scrambled word strings, the comprehension of sequential images must also use a cognitive system to distinguish coherent narrative sequences from random strings of images. We conducted experiments analogous to two classic studies of language processing to examine the contributions of narrative…

Interactive Learning through Web-Mediated Peer Review of Student Science Reports

ERIC Educational Resources Information Center

Trautmann, Nancy M.

2009-01-01

Two studies analyzed impacts of writing and receiving web-mediated peer reviews on revision of research reports by undergraduate science students. After conducting toxicology experiments, 77 students posted draft reports and exchanged double-blind reviews. The first study randomly assigned students to four groups representing full, partial, or no…

"Touch Me, Like Me": Testing an Encounter Group Assumption

ERIC Educational Resources Information Center

Boderman, Alvin; And Others

1972-01-01

An experiment to test an encounter group assumption that touching increases interpersonal attraction was conducted. College women were randomly assigned to a touch or no-touch condition. A comparison of total evaluation scores verified the hypothesis: subjects who touched the accomplice perceived her as a more attractive person than those who did…

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 ...

Evaluation of fungicide rotations for management of Phytophthora fruit rot of watermelon, 2015

USDA-ARS?s Scientific Manuscript database

The experiment was conducted at the U.S. Vegetable Laboratory farm in Charleston, SC. The soil was Yonges loamy fine sand. For the past 6 years, the field has been infested with Phytophthora capsici. The experimental design was a randomized complete block with four replications. Five-week-old seedli...

Embarking on College and Career: Interim Evaluation of Urban Alliance. Research Report

ERIC Educational Resources Information Center

Theodos, Brett; Pergamit, Michael R.; Hanson, Devlin; Edelstein, Sara; Daniels, Rebecca

2016-01-01

Urban Alliance serves at-risk youth through its high school internship program, which provides training, mentoring, and work experience to high school seniors from distressed communities. The program aims to help youth move on to higher education or employment after graduation. The Urban Institute is conducting a six-year, randomized controlled…

Integrating Reading Instruction into Vocational Agriculture Classes. Miscellaneous Publication 586. Contribution Number 3813.

ERIC Educational Resources Information Center

Sullivan, Dorothy D.; Cardozier, V.R.

An experiment was conducted to determine whether special reading instruction integrated with agricultural instruction would result in improved reading ability and increased achievement in subject matter. random assignment was made of vocational agriculture classes in 12 Maryland schools to experimental and control groups. Units on soil sampling…

Utilization of rye as energy source affects bacterial translocation, intestinal viscosity, microbiota composition, and bone mineralization in broiler chickens

USDA-ARS?s Scientific Manuscript database

Two independent trials were conducted to evaluate the effect of two different dietary cereal types, corn versus rye, on digesta viscosity, gut integrity, and gut microbiota composition in commercial broiler chickens. In each experiment, day-of-hatch, off-sex broiler chickens were randomly assigned ...

Observing and Deterring Social Cheating on College Exams

ERIC Educational Resources Information Center

Fendler, Richard J.; Yates, Michael C.; Godbey, Johnathan M.

2018-01-01

This research introduces a unique multiple choice exam design to observe and measure the degree to which students copy answers from their peers. Using data collected from the exam, an empirical experiment is conducted to determine whether random seat assignment deters cheating relative to a control group of students allowed to choose their seats.…

Student-Produced Videos Can Enhance Engagement and Learning in the Online Environment

ERIC Educational Resources Information Center

Stanley, Denise; Zhang, Yi

2018-01-01

Student engagement in online learning remains a challenge for the design of effective coursework. Additionally, few analyses have focused on student-produced activities in the online mode or upon how such class activity affects student subgroups differently. We conducted a randomized design experiment with student video production at a large…

Dynamical conductivity at the dirty superconductor-metal quantum phase transition

NASA Astrophysics Data System (ADS)

Hoyos, J. A.; Del Maestro, Adrian; Rosenow, Bernd; Vojta, Thomas

2011-03-01

We study the transport properties of ultrathin disordered nanowires in the neighborhood of the superconductor-metal quantum phase transition. To this end we combine numerical calculations with analytical strong-disorder renormalization group results. The quantum critical conductivity at zero temperature diverges logarithmically as a function of frequency. In the metallic phase, it obeys activated scaling associated with an infinite-randomness quantum critical point. We extend the scaling theory to higher dimensions and discuss implications for experiments. Financial support: Fapesp, CNPq, NSF, and Research Corporation.

Impacts of Child Development Accounts on maternal depressive symptoms: evidence from a randomized statewide policy experiment.

PubMed

Huang, Jin; Sherraden, Michael; Purnell, Jason Q

2014-07-01

This study examines the impact of Child Development Accounts (CDAs)-asset-building accounts created for children at birth-on the depressive symptoms of mothers in a statewide randomized experiment conducted in the United States. The experiment identified the primary caregivers of children born in Oklahoma during 2007, and 2704 of the caregivers completed a baseline interview before random assignment to the treatment (n = 1358) or the control group (n = 1346). To treatment participants, the experiment offered CDAs built on the existing Oklahoma 529 College Savings Plan. The baseline and follow-up surveys measured the participants' depressive symptoms with a shortened version of the Center for Epidemiologic Studies Depression Scale (CES-D). In models that control for baseline CES-D scores, the mean follow-up score of treatment mothers is .17 lower than that of control mothers (p < .05). Findings suggest that CDAs have a greater impact among subsamples that reported lower income or lower education. Although designed as an economic intervention for children, CDAs may improve parents' psychological well-being. Findings also suggest that CDAs' impacts on maternal depressive symptoms may be partially mediated through children's social-emotional development. Copyright © 2014 Elsevier Ltd. All rights reserved.

The Oregon health insurance experiment: when limited policy resources provide research opportunities.

PubMed

Allen, Heidi; Baicker, Katherine; Taubman, Sarah; Wright, Bill; Finkelstein, Amy

2013-12-01

In 2008 Oregon allocated access to its Medicaid expansion program, Oregon Health Plan Standard, by drawing names from a waiting list by lottery. The lottery was chosen by policy makers and stakeholders as the preferred way to allocate limited resources. At the same time, it also gave rise to the Oregon Health Insurance Experiment: an unprecedented opportunity to do a randomized evaluation - the gold standard in medical and scientific research - of the impact of expanding Medicaid. In this article we provide historical context for Oregon's decision to conduct a lottery, discuss the importance of randomized controlled designs for policy evaluation, and describe some of the practical challenges in successfully capitalizing on the research opportunity presented by the Oregon lottery through public-academic partnerships. Since policy makers will always face tough choices about how to distribute scarce resources, we urge thoughtful consideration of the opportunities to incorporate randomization that can substantially improve the evidence available to inform policy decisions without compromising policy goals.

Generation of dense plume fingers in saturated-unsaturated homogeneous porous media

NASA Astrophysics Data System (ADS)

Cremer, Clemens J. M.; Graf, Thomas

2015-02-01

Flow under variable-density conditions is widespread, occurring in geothermal reservoirs, at waste disposal sites or due to saltwater intrusion. The migration of dense plumes typically results in the formation of vertical plume fingers which are known to be triggered by material heterogeneity or by variations in source concentration that causes the density variation. Using a numerical groundwater model, six perturbation methods are tested under saturated and unsaturated flow conditions to mimic heterogeneity and concentration variations on the pore scale in order to realistically generate dense fingers. A laboratory-scale sand tank experiment is numerically simulated, and the perturbation methods are evaluated by comparing plume fingers obtained from the laboratory experiment with numerically simulated fingers. Dense plume fingering for saturated flow can best be reproduced with a spatially random, time-constant perturbation of the solute source. For unsaturated flow, a spatially and temporally random noise of solute concentration or a random conductivity field adequately simulate plume fingering.

Some karyological observations on plants grown in space

NASA Technical Reports Server (NTRS)

Krikorian, A. D.; Oconnor, S. A.

1982-01-01

Experiments were conducted to assess whether cell division in a plant root would be affected by prolonged exposure to microgravity. Root materials from sunflower, oat, and mung bean plants grown on STS-2 and STS-3 were utilized for the experiments. It is found that all oat, sunflower, and mung seedlings showed a reduced number of cells in division as they went through their first cell division cycle on earth when compared to their ground controls. A significant number of oat, mung, and sunflower plantlets exhibited random root orientation and the lack of strictly orthotropic growth of their shoot systems in the flight samples. In addition, it is found that the mung roots were apparently least affected in terms of their cytology despite the fact that their roots were often randomly oriented.

Does Money Really Matter? Estimating Impacts of Family Income on Young Children's Achievement With Data From Random-Assignment Experiments

PubMed Central

Duncan, Greg J.; Morris, Pamela A.; Rodrigues, Chris

2011-01-01

Social scientists do not agree on the size and nature of the causal impacts of parental income on children's achievement. We revisit this issue using a set of welfare and antipoverty experiments conducted in the 1990s. We utilize an instrumental variables strategy to leverage the variation in income and achievement that arises from random assignment to the treatment group to estimate the causal effect of income on child achievement. Our estimates suggest that a $1,000 increase in annual income increases young children's achievement by 5%–6% of a standard deviation. As such, our results suggest that family income has a policy-relevant, positive impact on the eventual school achievement of preschool children. PMID:21688900

The Effective Conductivity of Random Suspensions of Spherical Particles

NASA Astrophysics Data System (ADS)

Bonnecaze, R. T.; Brady, J. F.

1991-03-01

The effective conductivity of an infinite, random, mono-disperse, hard-sphere suspension is reported for particle to matrix conductivity ratios of ∞ , 10 and 0.01 for sphere volume fractions, c, up to 0.6. The conductivities are computed with a method previously described by the authors, which includes both far- and near-field interactions, and the particle configurations are generated via a Monte Carlo method. The results are consistent with the previous theoretical work of D. J. Jeffrey to O(c2) and the bounds computed by S. Torquato and F. Lado. It is also found that the Clausius-Mosotti equation is reasonably accurate for conductivity ratios of 10 or less all the way up to 60% (by volume). The calculated conductivities compare very well with those of experiments. In addition, percolation-like numerical experiments are performed on periodically replicated cubic lattices of N nearly touching spheres with an infinite particle to matrix conductivity ratio where the conductivity is computed as spheres are removed one by one from the lattice. Under suitable normalization of the conductivity and volume fraction, it is found that the initial volume fraction must be extremely close to maximum packing in order to observe a percolation transition, indicating that the near-field effects must be very large relative to far-field effects. These percolation transitions occur at the accepted values for simple (SC), bodycentred (BCC) and face-centred (FCC) cubic lattices. Also, the vulnerability of the lattices computed here are exactly those of previous investigators. Due to limited data above the percolation threshold, we could not correlate the conductivity with a power law near the threshold; however, it can be correlated with a power law for large normalized volume fractions. In this case the exponents are found to be 1.70, 1.75 and 1.79 for SC, BCC and FCC lattices respectively.

Electrical Stimulation for Pressure Injuries: A Health Technology Assessment.

PubMed

2017-01-01

Pressure injuries (bedsores) are common and reduce quality of life. They are also costly and difficult to treat. This health technology assessment evaluates the effectiveness, cost-effectiveness, budget impact, and lived experience of adding electrical stimulation to standard wound care for pressure injuries. We conducted a systematic search for studies published to December 7, 2016, limited to randomized and non-randomized controlled trials examining the effectiveness of electrical stimulation plus standard wound care versus standard wound care alone for patients with pressure injuries. We assessed the quality of evidence through Grading of Recommendations Assessment, Development, and Evaluation (GRADE). In addition, we conducted an economic literature review and a budget impact analysis to assess the cost-effectiveness and affordability of electrical stimulation for treatment of pressure ulcers in Ontario. Given uncertainties in clinical evidence and resource use, we did not conduct a primary economic evaluation. Finally, we conducted qualitative interviews with patients and caregivers about their experiences with pressure injuries, currently available treatments, and (if applicable) electrical stimulation. Nine randomized controlled trials and two non-randomized controlled trials were found from the systematic search. There was no significant difference in complete pressure injury healing between adjunct electrical stimulation and standard wound care. There was a significant difference in wound surface area reduction favouring electrical stimulation compared with standard wound care.The only study on cost-effectiveness of electrical stimulation was partially applicable to the patient population of interest. Therefore, the cost-effectiveness of electrical stimulation cannot be determined. We estimate that the cost of publicly funding electrical stimulation for pressure injuries would be $0.77 to $3.85 million yearly for the next 5 years.Patients and caregivers reported that pressure injuries were burdensome and reduced their quality of life. Patients and caregivers also noted that electrical stimulation seemed to reduce the time it took the wounds to heal. While electrical stimulation is safe to use (GRADE quality of evidence: high) there is uncertainty about whether it improves wound healing (GRADE quality of evidence: low). In Ontario, publicly funding electrical stimulation for pressure injuries could result in extra costs of $0.77 to $3.85 million yearly for the next 5 years.

N-state random switching based on quantum tunnelling

NASA Astrophysics Data System (ADS)

Bernardo Gavito, Ramón; Jiménez Urbanos, Fernando; Roberts, Jonathan; Sexton, James; Astbury, Benjamin; Shokeir, Hamzah; McGrath, Thomas; Noori, Yasir J.; Woodhead, Christopher S.; Missous, Mohamed; Roedig, Utz; Young, Robert J.

2017-08-01

In this work, we show how the hysteretic behaviour of resonant tunnelling diodes (RTDs) can be exploited for new functionalities. In particular, the RTDs exhibit a stochastic 2-state switching mechanism that could be useful for random number generation and cryptographic applications. This behaviour can be scaled to N-bit switching, by connecting various RTDs in series. The InGaAs/AlAs RTDs used in our experiments display very sharp negative differential resistance (NDR) peaks at room temperature which show hysteresis cycles that, rather than having a fixed switching threshold, show a probability distribution about a central value. We propose to use this intrinsic uncertainty emerging from the quantum nature of the RTDs as a source of randomness. We show that a combination of two RTDs in series results in devices with three-state outputs and discuss the possibility of scaling to N-state devices by subsequent series connections of RTDs, which we demonstrate for the up to the 4-state case. In this work, we suggest using that the intrinsic uncertainty in the conduction paths of resonant tunnelling diodes can behave as a source of randomness that can be integrated into current electronics to produce on-chip true random number generators. The N-shaped I-V characteristic of RTDs results in a two-level random voltage output when driven with current pulse trains. Electrical characterisation and randomness testing of the devices was conducted in order to determine the validity of the true randomness assumption. Based on the results obtained for the single RTD case, we suggest the possibility of using multi-well devices to generate N-state random switching devices for their use in random number generation or multi-valued logic devices.

Randoms Counter Analysis

NASA Astrophysics Data System (ADS)

Hensley, Winston; Giovanetti, Kevin

2008-10-01

A 1 ppm precision measurement of the muon lifetime is being conducted by the MULAN collaboration. The reason for this new measurement lies in recent advances in theory that have reduced the uncertainty in calculating the Fermi Coupling Constant from the measured lifetime to a few tenths ppm. The largest uncertainty is now experimental. To achieve a 1ppm level of precision it is necessary to control all sources of systematic error and to understand their influences on the lifetime measurement. James Madison University is contributing by examine the response of the timing system to uncorrelated events, randoms. A radioactive source was placed in front of paired detectors similar to those in the main experiment. These detectors were integrated in an identical fashion into the data acquisition and measurement system and data from these detectors was recorded during the entire experiment. The pair were placed in a shielded enclosure away from the main experiment to minimize interference. The data from these detectors should have a flat time spectrum as the decay of a radioactive source is a random event and has no time correlation. Thus the spectrum can be used as an important diagnostic in studying the method of determining event times and timing system performance.

Experiment Design for Complex VTOL Aircraft with Distributed Propulsion and Tilt Wing

NASA Technical Reports Server (NTRS)

Murphy, Patrick C.; Landman, Drew

2015-01-01

Selected experimental results from a wind tunnel study of a subscale VTOL concept with distributed propulsion and tilt lifting surfaces are presented. The vehicle complexity and automated test facility were ideal for use with a randomized designed experiment. Design of Experiments and Response Surface Methods were invoked to produce run efficient, statistically rigorous regression models with minimized prediction error. Static tests were conducted at the NASA Langley 12-Foot Low-Speed Tunnel to model all six aerodynamic coefficients over a large flight envelope. This work supports investigations at NASA Langley in developing advanced configurations, simulations, and advanced control systems.

Group Parent-Child Interaction Therapy: A Randomized Control Trial for the Treatment of Conduct Problems in Young Children

PubMed Central

Niec, Larissa N.; Barnett, Miya L.; Prewett, Matthew S.; Shanley, Jenelle

2016-01-01

Objective Although efficacious interventions exist for childhood conduct problems, a majority of families in need of services do not receive them. To address problems of treatment access and adherence, innovative adaptations of current interventions are needed. This randomized control trial investigated the relative efficacy of a novel format of parent-child interaction therapy (PCIT), a treatment for young children with conduct problems. Methods Eighty-one families with three- to six-year-old children (71.6% male; 85.2% Caucasian) with diagnoses of oppositional defiant or conduct disorder were randomized to individual PCIT (n = 42) or the novel format, group PCIT. Parents completed standardized measures of children’s conduct problems, parenting stress, and social support at intake, posttreatment, and six-month follow-up. Therapist ratings, parent attendance, and homework completion provided measures of treatment adherence. Throughout treatment, parenting skills were assessed using the Dyadic Parent-Child Interaction Coding System. Results Parents in both group and individual PCIT reported significant improvements from intake to posttreatment and follow-up in their children’s conduct problems and adaptive functioning, as well as significant decreases in parenting stress. Parents in both treatment conditions also showed significant improvements in their parenting skills. There were no interactions between time and treatment format. Contrary to expectation, parents in group PCIT did not experience greater social support or treatment adherence. Conclusions Group PCIT was not inferior to individual PCIT and may be a valuable format to reach more families in need of services. Future work should explore the efficiency and sustainability of group PCIT in community settings. PMID:27018531

The stability of hydrogen ion and specific conductance in filtered wet-deposition samples stored at ambient temperatures

USGS Publications Warehouse

Gordon, J.D.; Schroder, L.J.; Morden-Moore, A. L.; Bowersox, V.C.

1995-01-01

Separate experiments by the U.S. Geological Survey (USGS) and the Illinois State Water Survey Central Analytical Laboratory (CAL) independently assessed the stability of hydrogen ion and specific conductance in filtered wet-deposition samples stored at ambient temperatures. The USGS experiment represented a test of sample stability under a diverse range of conditions, whereas the CAL experiment was a controlled test of sample stability. In the experiment by the USGS, a statistically significant (?? = 0.05) relation between [H+] and time was found for the composited filtered, natural, wet-deposition solution when all reported values are included in the analysis. However, if two outlying pH values most likely representing measurement error are excluded from the analysis, the change in [H+] over time was not statistically significant. In the experiment by the CAL, randomly selected samples were reanalyzed between July 1984 and February 1991. The original analysis and reanalysis pairs revealed that [H+] differences, although very small, were statistically different from zero, whereas specific-conductance differences were not. Nevertheless, the results of the CAL reanalysis project indicate there appears to be no consistent, chemically significant degradation in sample integrity with regard to [H+] and specific conductance while samples are stored at room temperature at the CAL. Based on the results of the CAL and USGS studies, short-term (45-60 day) stability of [H+] and specific conductance in natural filtered wet-deposition samples that are shipped and stored unchilled at ambient temperatures was satisfactory.

Effect of fungicides on anthracnose and grain mold of sorghum in Wharton County, Texas, 2016

USDA-ARS?s Scientific Manuscript database

The experiment was conducted in Wharton County, Texas using the hybrid BH 5566. There were four replicates per treatment arranged in a randomized, blocked factorial design. Each replicate consisted of four, 20.5-ft rows, with 38-in. row spacing and a plant spacing of 1.9 in. within rows. Three fu...

Humor in the Classroom: The Effects of Integrated Humor on Student Learning

ERIC Educational Resources Information Center

Bolkan, San; Griffin, Darrin J.; Goodboy, Alan K.

2018-01-01

This study was conducted to examine the impact of integrated humor on direct measures of students' ability to retain and transfer information from educational lessons. In two experiments, participants were randomly exposed to either a lesson with humorous examples or standard examples and were subsequently asked to take tests on the material. Data…

Environmental Education through Narrative Films: Impact of "Medicine Man" on Attitudes toward Forest Preservation

ERIC Educational Resources Information Center

Bahk, C. Mo

2011-01-01

Narrative film is a multimodal, multisensual, and universal medium that has potential to reach and influence a wide range of people regarding environmental issues. The author conducted an experiment to explore the impact of film portrayals of deforestation among college students. One-hundred eighty-one undergraduate students were randomly assigned…

The Relative Efficacy of Video and Text Tutorials in Online Computing Education

ERIC Educational Resources Information Center

Lang, Guido

2016-01-01

This study tests the effects of tutorial format (i.e. video vs. text) on student attitudes and performance in online computing education. A one-factor within-subjects experiment was conducted in an undergraduate Computer Information Systems course. Subjects were randomly assigned to complete two Excel exercises online: one with a video tutorial…

The Perception of Public Secondary Education through the Lens of African American Male Students

ERIC Educational Resources Information Center

Dandridge, Janae' K.

2012-01-01

This study examines the perspective of public secondary education through the lived experiences and voices of 10 African American male students. The study was qualitative in nature and utilized an action research case study design. The researcher conducted semi structured interviews with a randomly selected group of African American male students…

Evaluation of fungicide rotations and MELCAST for management of Phytophthora fruit rot of watermelon, 2014

USDA-ARS?s Scientific Manuscript database

The experiment was conducted at the U.S. Vegetable Laboratory farm in Charleston, SC. The soil was Yonges loamy fine sand, and for the past 5 years, the field has been infested with Phytophthora capsici. The experimental design was a randomized complete block with four replications. Four-week-old...

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…

Behavioral changes and feathering score in heat stressed broiler chickens fed diets containing different levels of propolis

USDA-ARS?s Scientific Manuscript database

This experiment was conducted to evaluate the effects of dietary supplementation of green Brazilian propolis on behavioral patterns and feather condition of heat stressed broiler chickens. Five hundred and four (504) male Ross 708 broiler chicks at 15-day old were randomly allotted to six dietary tr...

What Affects People's Willingness to Participate in Qualitative Research? An Experimental Comparison of Five Incentives

ERIC Educational Resources Information Center

Kelly, Bridget; Margolis, Marjorie; McCormack, Lauren; LeBaron, Patricia A.; Chowdhury, Dhuly

2017-01-01

The literature on factors that influence participation in qualitative research is lacking. We conducted an experiment with a nationally representative sample to test the impact of different incentive types and amounts on willingness to participate in a hypothetical qualitative interview. We randomized participants from an online panel to one of…

Teachers' Perceptions of Employment-Related Problems: A Survey of Teachers in Two States.

ERIC Educational Resources Information Center

Cutrer, Susan S.; Daniel, Larry G.

This study was conducted to determine the degree to which a randomly selected sample of teachers in Mississippi and Louisiana (N=291) experience various types of work-related problems. It provides an opportunity to either confirm or deny the findings of previous studies, many of them limited by various methodological problems. Data were collected…

A Qualitative Study of Irish Teachers' Perspective of Student Substance Use

ERIC Educational Resources Information Center

Van Hout, Marie Claire; Connor, Sean

2008-01-01

Research Aim: This research aimed to provide an anecdotal perception of student substance use according to the teachers' personal experience in the Irish secondary level educational setting. Methodology: Sampling Interviews were conducted with teachers (n=95) at 10 randomly selected schools in County Carlow in the South East of Ireland, as part of…

Ketogenic Diet Based on Extra Virgin Coconut Oil Has No Effects in Young Wistar Rats With Pilocarpine-Induced Epilepsy.

PubMed

Melo, Isabelle T; M Rêgo, Elisabete; Bueno, Nassib B; Gomes, Tâmara C; Oliveira, Suzana L; Trindade-Filho, Euclides M; Cabral, Cyro R; Machado, Tacy S; Galvão, Jaqueline A; R Ataide, Terezinha

2018-02-01

This study evaluated the effects of a ketogenic diet (KD) based on extra virgin coconut oil (Cocos nucifera L., VCO), on the treatment of epileptic rats. Two sets of experiments were conducted. First, male Wistar rats underwent induction of status epilepticus (SE) with the administration of pilocarpine intraperitoneally 21 animals reached spontaneous recurrent seizures (SRS) and were randomly allocated to the dietary regimens and video-monitored for 19 days. In the second experiment, 24 animals were randomized immediately after the induction of SE and followed for 67 days. Diets were as follows: Control (AIN-93G; 7% lipid), KetoTAGsoya (KD based on soybean oil; 69.79% lipid), and KetoTAGcoco (KD based on VCO; 69.79% lipid). There were no differences in the latency to the first crisis, total frequency, and duration of the SRS between groups in 2 experiments. The data suggest no effects of KD, with or without VCO, in rats with pilocarpine-induced epilepsy. © 2018 AOCS.

Accounting for therapist variability in couple therapy outcomes: what really matters?

PubMed

Owen, Jesse; Duncan, Barry; Reese, Robert Jeff; Anker, Morten; Sparks, Jacqueline

2014-01-01

This study examined whether therapist gender, professional discipline, experience conducting couple therapy, and average second-session alliance score would account for the variance in outcomes attributed to the therapist. The authors investigated therapist variability in couple therapy with 158 couples randomly assigned to and treated by 18 therapists in a naturalistic setting. Consistent with previous studies in individual therapy, in this study therapists accounted for 8.0% of the variance in client outcomes and 10% of the variance in client alliance scores. Therapist average alliance score and experience conducting couple therapy were salient predictors of client outcomes attributed to therapist. In contrast, therapist gender and discipline did not significantly account for the variance in client outcomes attributed to therapists. Tests of incremental validity demonstrated that therapist average alliance score and therapist experience uniquely accounted for the variance in outcomes attributed to the therapist. Emphasis on improving therapist alliance quality and specificity of therapist experience in couple therapy are discussed.

Effects of monetary reward and punishment on information checking behaviour.

PubMed

Li, Simon Y W; Cox, Anna L; Or, Calvin; Blandford, Ann

2016-03-01

Two experiments were conducted to examine whether checking one's own work can be motivated by monetary reward and punishment. Participants were randomly assigned to one of three conditions: a flat-rate payment for completing the task (Control); payment increased for error-free performance (Reward); payment decreased for error performance (Punishment). Experiment 1 (N = 90) was conducted with liberal arts students, using a general data-entry task. Experiment 2 (N = 90) replicated Experiment 1 with clinical students and a safety-critical 'cover story' for the task. In both studies, Reward and Punishment resulted in significantly fewer errors, more frequent and longer checking, than Control. No such differences were obtained between the Reward and Punishment conditions. It is concluded that error consequences in terms of monetary reward and punishment can result in more accurate task performance and more rigorous checking behaviour than errors without consequences. However, whether punishment is more effective than reward, or vice versa, remains inconclusive. Copyright © 2015 Elsevier Ltd and The Ergonomics Society. All rights reserved.

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

Dynamic speckle - Interferometry of micro-displacements

NASA Astrophysics Data System (ADS)

Vladimirov, A. P.

2012-06-01

The problem of the dynamics of speckles in the image plane of the object, caused by random movements of scattering centers is solved. We consider three cases: 1) during the observation the points move at random, but constant speeds, and 2) the relative displacement of any pair of points is a continuous random process, and 3) the motion of the centers is the sum of a deterministic movement and random displacement. For the cases 1) and 2) the characteristics of temporal and spectral autocorrelation function of the radiation intensity can be used for determining of individually and the average relative displacement of the centers, their dispersion and the relaxation time. For the case 3) is showed that under certain conditions, the optical signal contains a periodic component, the number of periods is proportional to the derivations of the deterministic displacements. The results of experiments conducted to test and application of theory are given.

Report on hard red spring wheat varieties grown in cooperative plot and nursery experiments in the spring wheat region in 2016

USDA-ARS?s Scientific Manuscript database

The Hard Red Spring Wheat Uniform Regional Nursery (HRSWURN) was planted for the 86th year in 2016. The nursery contained 26 entries submitted by 8 different scientific or industry breeding programs, and 5 checks (Table 1). Trials were conducted as randomized complete blocks with three replicates ...

The Validity and Precision of the Comparative Interrupted Time-Series Design: Three Within-Study Comparisons

ERIC Educational Resources Information Center

St. Clair, Travis; Hallberg, Kelly; Cook, Thomas D.

2016-01-01

We explore the conditions under which short, comparative interrupted time-series (CITS) designs represent valid alternatives to randomized experiments in educational evaluations. To do so, we conduct three within-study comparisons, each of which uses a unique data set to test the validity of the CITS design by comparing its causal estimates to…

Empirical Benchmarks of Hidden Bias in Educational Research: Implication for Assessing How well Propensity Score Methods Approximate Experiments and Conducting Sensitivity Analysis

ERIC Educational Resources Information Center

Dong, Nianbo; Lipsey, Mark

2014-01-01

When randomized control trials (RCT) are not feasible, researchers seek other methods to make causal inference, e.g., propensity score methods. One of the underlined assumptions for the propensity score methods to obtain unbiased treatment effect estimates is the ignorability assumption, that is, conditional on the propensity score, treatment…

Prevalence and Mental Health Correlates of Harassment and Discrimination in the Workplace: Results from a National Study

ERIC Educational Resources Information Center

Rospenda, Kathleen M.; Richman, Judith A.; Shannon, Candice A.

2009-01-01

This study describes past-year prevalence and effects on mental health and drinking outcomes for harassment and discrimination in the workplace (HDW) in a nationally representative random digit dial phone survey conducted in 2003-2004 (n = 2,151). HDW measures included experiences and perceptions of sexual harassment (SH) and generalized workplace…

An Experimental Study for Effectiveness of Super-Learning Technique at Elementary Level in Pakistan

ERIC Educational Resources Information Center

Shafqat, Hussain; Muhammad, Sarwar; Imran, Yousaf; Naemullah; Inamullah

2010-01-01

The objective of the study was to experience the effectiveness of super-learning technique of teaching at elementary level. The study was conducted with 8th grade students at a public sector school. Pre-test and post-test control group designs were used. Experimental and control groups were formed randomly, the experimental group (N = 62),…

Development of Teaching Beliefs and the Focus of Change in the Process of Pre-Service ESL Teacher Education

ERIC Educational Resources Information Center

Tang, Eunice Lai-Yiu; Lee, John Chi-Kin; Chun, Cecilia Ka-Wai

2012-01-01

This study sets out to investigate how pre-service ESL teachers shape their beliefs in the process of experimenting with new teaching methods introduced in the teacher education programme. A 4-year longitudinal study was conducted with four randomly selected ESL pre-service teachers. Their theoretical orientations of ESL instruction were tracked…

YouTube and Skype Modes of Virtual Learning Performance in Relations to Cognitive Styles of Students

ERIC Educational Resources Information Center

Jena, Ananta Kumar; Deka, Monisha; Barman, Munmi

2017-01-01

The study aimed to find out the relationship between cognitive styles, YouTube learning and Skype learning performance of secondary school students. For that purpose, the researchers randomly selected 20 students from two 9th standards of two English medium secondary schools of Silchar Town, Assam, India to conduct the experiment. Quasi…

Corn or sorghum wet distiller's grains with solubles in combination with steam-flaked corn: Feedlot cattle performance, carcass characteristics, and apparent total tract digestibility

USDA-ARS?s Scientific Manuscript database

Two studies were conducted to evaluate corn (CDG) and sorghum (SDG) wet distiller's grains with solubles on feedlot cattle performance, carcass characteristics, apparent total tract digestion of nutrients, and marker retention time. In Experiment 1, 224 steers were used in a randomized complete bloc...

Evaluation of the Effectiveness of the Alabama Math, Science, and Technology Initiative (AMSTI). Final Report. NCEE 2012-4008

ERIC Educational Resources Information Center

Newman, Denis; Finney, Pamela B.; Bell, Steve; Turner, Herb; Jaciw, Andrew P.; Zacamy, Jenna L.; Gould, Laura Feagans

2012-01-01

This report presents the results of an experiment conducted in Alabama beginning in the 2006/07 school year, to determine the effectiveness of the Alabama Math, Science, and Technology Initiative (AMSTI), which aims to improve mathematics and science achievement in the state's K-12 schools. This study is the first randomized controlled trial…

Report on hard red spring wheat varieties grown in cooperative plot and nursery experiments in the spring wheat region in 2014

USDA-ARS?s Scientific Manuscript database

The Hard Red Spring Wheat Uniform Regional Nursery (HRSWURN) was planted for the 84th year in 2014. The nursery contained 26 entries submitted by 6 different scientific or industry breeding programs, and 5 checks (Table 1). Trials were conducted as randomized complete blocks with three replicates ex...

Transitioning the GED[R] Mathematics Test to Computer with and without Accommodations: A Pilot Project

ERIC Educational Resources Information Center

Patterson, Margaret Becker; Higgins, Jennifer; Bozman, Martha; Katz, Michael

2011-01-01

We conducted a pilot study to see how the GED Mathematics Test could be administered on computer with embedded accessibility tools. We examined test scores and test-taker experience. Nineteen GED test centers across five states and 216 randomly assigned GED Tests candidates participated in the project. GED candidates completed two GED mathematics…

Continuous Practice-Based Research on the Use of Standardized Patients: Experience from Shanghai Medical College of Fudan University

ERIC Educational Resources Information Center

Zeng, Yong; Wu, Yan; Lai, Yanni; Lu, Yingqing; Zou, Hejian; Feng, Xueshan

2014-01-01

In the past ten years, the objective structured clinical examination (OSCE) project team of the Shanghai Medical College of Fudan University has continuously conducted further study on the development and maintenance of standardized patients and their application in teaching. The team carried out a series of randomized controlled studies on the…

Acceptance and Commitment Therapy for Inpatients with Psychosis (the REACH Study): Protocol for Treatment Development and Pilot Testing

PubMed Central

Gaudiano, Brandon A.; Davis, Carter H.; Epstein-Lubow, Gary; Johnson, Jennifer E.; Mueser, Kim T.; Miller, Ivan W.

2017-01-01

Patients with schizophrenia-spectrum disorders frequently require treatment at inpatient hospitals during periods of acute illness for crisis management and stabilization. Acceptance and Commitment Therapy (ACT), a “third wave” cognitive-behavioral intervention that employs innovative mindfulness-based strategies, has shown initial efficacy in randomized controlled trials for improving acute and post-discharge outcomes in patients with psychosis when studied in acute-care psychiatric hospitals in the U.S. However, the intervention has not been widely adopted in its current form because of its use of an individual-only format and delivery by doctoral-level research therapists with extensive prior experience using ACT. The aim of the Researching the Effectiveness of Acceptance-based Coping during Hospitalization (REACH) Study is to adapt a promising acute-care psychosocial treatment for inpatients with psychosis, and to pilot test its effectiveness in a routine inpatient setting. More specifically, we describe our plans to: (a) further develop and refine the treatment and training protocols, (b) conduct an open trial and make further modifications based on the experience gained, and (c) conduct a pilot randomized controlled trial in preparation for a future fully-powered clinical trial testing the effectiveness of ACT. PMID:28475123

47 CFR 1.1603 - Conduct of random selection.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 1 2010-10-01 2010-10-01 false Conduct of random selection. 1.1603 Section 1.1603 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Random Selection Procedures for Mass Media Services General Procedures § 1.1603 Conduct of random selection. The...

47 CFR 1.1603 - Conduct of random selection.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 1 2011-10-01 2011-10-01 false Conduct of random selection. 1.1603 Section 1.1603 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Random Selection Procedures for Mass Media Services General Procedures § 1.1603 Conduct of random selection. The...

Testing and Analysis of Sensor Ports

NASA Technical Reports Server (NTRS)

Zhang, M.; Frendi, A.; Thompson, W.; Casiano, M. J.

2016-01-01

This Technical Publication summarizes the work focused on the testing and analysis of sensor ports. The tasks under this contract were divided into three areas: (1) Development of an Analytical Model, (2) Conducting a Set of Experiments, and (3) Obtaining Computational Solutions. Results from the experiment using both short and long sensor ports were obtained using harmonic, random, and frequency sweep plane acoustic waves. An amplification factor of the pressure signal between the port inlet and the back of the port is obtained and compared to models. Comparisons of model and experimental results showed very good agreement.

Effects of Assertiveness Training and Expressive Writing on Acculturative Stress in International Students: A Randomized Trial

PubMed Central

Tavakoli, Shedeh; Lumley, Mark A.; Hijazi, Alaa M.; Slavin-Spenny, Olga M.; Parris, George P.

2010-01-01

International university students often experience acculturative stress, and culturally appropriate techniques to manage stress are needed. This randomized trial tested the effects of group assertiveness training, private expressive writing, their combination, and a wait-list control on the acculturative stress, affect, and health of 118 international students at an urban, American university. Interventions were conducted at the start of a semester, and assessments were conducted at baseline and the end of the semester. Group assertiveness training was rated positively by students and led to lower negative affect, whereas expressive writing was less well received and led to higher homesickness and fear, but also higher positive affect. The combined intervention had no effects, perhaps because the two components negated each other. It is concluded that group assertiveness training improves emotional adjustment of international students, but expressive writing has mixed effects and needs further development and study. PMID:20357910

Why the evidence for outpatient commitment is good enough.

PubMed

Swanson, Jeffrey W; Swartz, Marvin S

2014-06-01

After nearly three decades of studies evaluating the legal practice of involuntary outpatient commitment, there is yet little consensus about its effectiveness and only limited implementation. Debate continues over how best to assist adults with serious mental illnesses who are unable or unwilling to participate in prescribed community treatment and as a result experience repeated involuntary hospitalizations or involvement with the criminal justice system. The authors comment on the Oxford Community Treatment Order Evaluation Trial (OCTET), a recently conducted randomized trial of outpatient commitment, and discuss the limitations of the study's design for resolving the persistent question of whether compulsory treatment is more effective than purely voluntary treatment for this difficult-to-reach target population. The authors conclude that the search for a definitive and generalizable randomized trial of outpatient commitment may be a quixotic quest; the field should, rather, welcome the results of well-conducted, large-scale, quasi-experimental and naturalistic studies with rigorous multivariable statistical controls.

Group parent-child interaction therapy: A randomized control trial for the treatment of conduct problems in young children.

PubMed

Niec, Larissa N; Barnett, Miya L; Prewett, Matthew S; Shanley Chatham, Jenelle R

2016-08-01

Although efficacious interventions exist for childhood conduct problems, a majority of families in need of services do not receive them. To address problems of treatment access and adherence, innovative adaptations of current interventions are needed. This randomized control trial investigated the relative efficacy of a novel format of parent-child interaction therapy (PCIT), a treatment for young children with conduct problems. Eighty-one families with 3- to 6-year-old children (71.6% boys, 85.2% White) with diagnoses of oppositional defiant or conduct disorder were randomized to individual PCIT (n = 42) or the novel format, Group PCIT. Parents completed standardized measures of children's conduct problems, parenting stress, and social support at intake, posttreatment, and 6-month follow-up. Therapist ratings, parent attendance, and homework completion provided measures of treatment adherence. Throughout treatment, parenting skills were assessed using the Dyadic Parent-Child Interaction Coding System. Parents in both group and individual PCIT reported significant improvements from intake to posttreatment and follow-up in their children's conduct problems and adaptive functioning, as well as significant decreases in parenting stress. Parents in both treatment conditions also showed significant improvements in their parenting skills. There were no interactions between time and treatment format. Contrary to expectation, parents in Group PCIT did not experience greater social support or treatment adherence. Group PCIT was not inferior to individual PCIT and may be a valuable format to reach more families in need of services. Future work should explore the efficiency and sustainability of Group PCIT in community settings. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Provider training to screen and initiate evidence-based pediatric obesity treatment in routine practice settings: A randomized pilot trial

PubMed Central

Kolko, Rachel P.; Kass, Andrea E.; Hayes, Jacqueline F.; Levine, Michele D.; Garbutt, Jane M.; Proctor, Enola K.; Wilfley, Denise E.

2016-01-01

Introduction This randomized pilot trial evaluated two training modalities for first-line, evidence-based pediatric obesity services (screening and goal-setting) among nursing students. Method Participants (N=63) were randomized to Live Interactive Training (Live) or Web-facilitated Self-study Training (Web). Pre-training, post-training, and one-month follow-up assessments evaluated training feasibility, acceptability, and impact (knowledge, and skill via simulation). Moderator (previous experience) and predictor (content engagement) analyses were conducted. Results Nearly-all (98%) participants completed assessments. Both trainings were acceptable, with higher ratings for Live and participants with previous experience (p’s<.05). Knowledge and skill improved from pre-training to post-training and follow-up in both conditions (p’s<.001). Live demonstrated greater content engagement (p’s<.01). Conclusions The training package was feasible, acceptable, and efficacious among nursing students. Given that Live had higher acceptability and engagement, and online training offers greater scalability, integrating interactive Live components within Web-based training may optimize outcomes, which may enhance practitioners’ delivery of pediatric obesity services. PMID:26873293

A Experimental Investigation of Hydrodynamic Forces on Circular Cylinders in Sinusoidal and Random Oscillating Flow

NASA Astrophysics Data System (ADS)

Longoria, Raul Gilberto

An experimental apparatus has been developed which can be used to generate a general time-dependent planar flow across a cylinder. A mass of water enclosed with no free surface within a square cross-section tank and two spring pre-loaded pistons is oscillated using a hydraulic actuator. A circular cylinder is suspended horizontally in the tank by two X-Y force transducers used to simultaneously measure the total in-line and transverse forces. Fluid motion is measured using a differential pressure transducer for instantaneous acceleration and an LVDT for displacement. This investigation provides measurement of forces on cylinders subjected to planar fluid flow velocity with a time (and frequency) dependence which more accurately represent the random conditions encountered in a natural ocean environment. The use of the same apparatus for both sinusoidal and random experiments provides a quantified assessment of the applicability of sinusoidal planar oscillatory flow data in offshore structure design methods. The drag and inertia coefficients for a Morison equation representation of the inline force are presented for both sinusoidal and random flow. Comparison of the sinusoidal results is favorable with those of previous investigations. The results from random experiments illustrates the difference in the force mechanism by contrasting the force transfer coefficients for the inline and transverse forces. It is found that application of sinusoidal results to random hydrodynamic inline force prediction using the Morison equation wrongly weighs the drag and inertia components, and the transverse force is overpredicted. The use of random planar oscillatory flow in the laboratory, contrasted with sinusoidal planar oscillatory flow, quantifies the accepted belief that the force transfer coefficients from sinusoidal flow experiments are conservative for prediction of forces on cylindrical structures subjected to random sea waves and the ensuing forces. Further analysis of data is conducted in the frequency domain to illustrate models used for predicting the power spectral density of the inline force including a nonlinear describing function method. It is postulated that the large-scale vortex activity prominent in sinusoidal oscillatory flow is subdued in random flow conditions.

[Effect of Xinling Wan in treatment of stable angina pectoris: a randomized, double-blinded, placebo parallel-controlled, multicenter trial].

PubMed

Gao, Jian-Wei; Gao, Xue-Min; Zou, Ting; Zhao, Tian-Meng; Wang, Dong-Hua; Wu, Zong-Gui; Ren, Chang-Jie; Wang, Xing; Geng, Nai-Zhi; Zhao, Ming-Jun; Liang, Qiu-Ming; Feng, Xing; Yang, Bai-Song; Shi, Jun-Ling; Hua, Qi

2018-03-01

To evaluate the effectiveness and safety of Xinling Wan on patients with stable angina pectoris, a randomized, double-blinded, placebo parallel-controlled, multicenter clinical trial was conducted. A total of 232 subjects were enrolled and randomly divided into experiment group and placebo group. The experiment group was treated with Xinling Wan (two pills each time, three times daily) for 4 weeks, and the placebo group was treated with placebo. The effectiveness evaluation showed that Xinling Wan could significantly increase the total duration of treadmill exercise among patients with stable angina pectoris. FAS analysis showed that the difference value of the total exercise duration was between experiment group (72.11±139.32) s and placebo group (31.25±108.32) s. Xinling Wan could remarkably increase the total effective rate of angina pectoris symptom score, and the analysis showed that the total effective rate was 78.95% in experiment group and 42.61% in placebo group. The reduction of nitroglycerin dose was (2.45±2.41) tablets in experiment group and (0.50±2.24) tablets in placebo group on the basis of FAS analysis. The decrease of symptom integral was (4.68±3.49) in experiment group and (3.19±3.31) in placebo group based on FAS analysis. Besides, Xinling Wan could decrease the weekly attack time and the duration of angina pectoris. PPS analysis results were similar to those of FAS analysis. In conclusion, Xinling Wan has an obvious therapeutic effect in treating stable angina pectoris, with a good safety and a low incidence of adverse event and adverse reaction in experiment group. Copyright© by the Chinese Pharmaceutical Association.

Gain in Student Understanding of the Role of Random Variation in Evolution Following Teaching Intervention Based on Luria-Delbruck Experiment†

PubMed Central

Robson, Rachel L.; Burns, Susan

2011-01-01

Undergraduate students in introductory biology classes are typically saddled with pre-existing popular beliefs that impede their ability to learn about biological evolution. One of the most common misconceptions about evolution is that the environment causes advantageous mutations, rather than the correct view that mutations occur randomly and the environment only selects for mutants with advantageous traits. In this study, a significant gain in student understanding of the role of randomness in evolution was observed after students participated in an inquiry-based pedagogical intervention based on the Luria-Delbruck experiment. Questionnaires with isomorphic questions regarding environmental selection among random mutants were administered to study participants (N = 82) in five separate sections of a sophomore-level microbiology class before and after the teaching intervention. Demographic data on each participant was also collected, in a way that preserved anonymity. Repeated measures analysis showed that post-test scores were significantly higher than pre-test scores with regard to the questions about evolution (F(1, 77) = 25.913, p < 0.001). Participants’ pre-existing beliefs about evolution had no significant effect on gain in understanding of this concept. This study indicates that conducting and discussing an experiment about phage resistance in E. coli may improve student understanding of the role of stochastic events in evolution more broadly, as post-test answers showed that students were able to apply the lesson of the Luria-Delbruck experiment to other organisms subjected to other kinds of selection. PMID:23653732

The Functional Measurement Experiment Builder suite: two Java-based programs to generate and run functional measurement experiments.

PubMed

Mairesse, Olivier; Hofmans, Joeri; Theuns, Peter

2008-05-01

We propose a free, easy-to-use computer program that does not requires prior knowledge of computer programming to generate and run experiments using textual or pictorial stimuli. Although the FM Experiment Builder suite was initially programmed for building and conducting FM experiments, it can also be applied for non-FM experiments that necessitate randomized, single, or multifactorial designs. The program is highly configurable, allowing multilingual use and a wide range of different response formats. The outputs of the experiments are Microsoft Excel compatible .xls files that allow easy copy-paste of the results into Weiss's FM CalSTAT program (2006) or any other statistical package. Its Java-based structure is compatible with both Windows and Macintosh operating systems, and its compactness (< 1 MB) makes it easily distributable over the Internet.

Hydrogen doping in HfO{sub 2} resistance change random access memory

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

Duncan, D.; Magyari-Köpe, B.; Nishi, Y.

2016-01-25

The structures and energies of hydrogen-doped monoclinic hafnium dioxide were calculated using density-functional theory. The electronic interactions are described within the LDA + U formalism, where on-site Coulomb corrections are applied to the 5d orbital electrons of Hf atoms and 2p orbital electrons of the O atoms. The effects of charge state, defect-defect interactions, and hydrogenation are investigated and compared with experiment. It is found that hydrogenation of HfO{sub 2} resistance-change random access memory devices energetically stabilizes the formation of oxygen vacancies and conductive vacancy filaments through multiple mechanisms, leading to improved switching characteristic and device yield.

Study of Dynamic Characteristics of Aeroelastic Systems Utilizing Randomdec Signatures

NASA Technical Reports Server (NTRS)

Chang, C. S.

1975-01-01

The feasibility of utilizing the random decrement method in conjunction with a signature analysis procedure to determine the dynamic characteristics of an aeroelastic system for the purpose of on-line prediction of potential on-set of flutter was examined. Digital computer programs were developed to simulate sampled response signals of a two-mode aeroelastic system. Simulated response data were used to test the random decrement method. A special curve-fit approach was developed for analyzing the resulting signatures. A number of numerical 'experiments' were conducted on the combined processes. The method is capable of determining frequency and damping values accurately from randomdec signatures of carefully selected lengths.

Effects of leisure education on self-rated health among older adults.

PubMed

Chang, Liang-Chih; Yu, Ping; Jeng, Mei-Yuan

2015-01-01

This study examined whether a leisure education program could promote leisure autonomy and self-rated health (SRH) among older adults. A pretest-posttest randomized experimental design was conducted. Subjects were randomly assigned to either an experimental group (n = 30) or a control group (n = 30). Data related to leisure autonomy and SRH were collected shortly before and after the experiment. Pretest and posttest data were analyzed using an analysis of covariance. The results indicated that the average posttest scores of leisure autonomy and SRH in the experimental group were significantly higher than those in the control group. Implications of the results are discussed.

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.

Efficacy of attention bias modification using threat and appetitive stimuli: a meta-analytic review.

PubMed

Beard, Courtney; Sawyer, Alice T; Hofmann, Stefan G

2012-12-01

Attention bias modification (ABM) protocols aim to modify attentional biases underlying many forms of pathology. Our objective was to conduct an effect size analysis of ABM across a wide range of samples and psychological problems. We conducted a literature search using PubMed, PsycInfo, and author searches to identify randomized studies that examined the effects of ABM on attention and subjective experiences. We identified 37 studies (41 experiments) totaling 2,135 participants who were randomized to training toward neutral, positive, threat, or appetitive stimuli or to a control condition. The effect size estimate for changes in attentional bias was large for the neutral versus threat comparisons (g=1.06), neutral versus appetitive (g=1.41), and neutral versus control comparisons (g=0.80), and small for positive versus control (g=0.24). The effects of ABM on attention bias were moderated by stimulus type (words vs. pictures) and sample characteristics (healthy vs. high symptomatology). Effect sizes of ABM on subjective experiences ranged from 0.03 to 0.60 for postchallenge outcomes, -0.31 to 0.51 for posttreatment, and were moderated by number of training sessions, stimulus type, and stimulus orientation (top/bottom vs. left/right). Fail-safe N calculations suggested that the effect size estimates were robust for the training effects on attentional biases, but not for the effect on subjective experiences. ABM studies using threat stimuli produced significant effects on attention bias across comparison conditions, whereas appetitive stimuli produced changes in attention only when comparing appetitive versus neutral conditions. ABM has a moderate and robust effect on attention bias when using threat stimuli. Further studies are needed to determine whether these effects are also robust when using appetitive stimuli and for affecting subjective experiences. Copyright © 2012. Published by Elsevier Ltd.

Electrical Stimulation for Pressure Injuries: A Health Technology Assessment

PubMed Central

Lambrinos, Anna; Falk, Lindsey; Ali, Arshia; Holubowich, Corinne; Walter, Melissa

2017-01-01

Background Pressure injuries (bedsores) are common and reduce quality of life. They are also costly and difficult to treat. This health technology assessment evaluates the effectiveness, cost-effectiveness, budget impact, and lived experience of adding electrical stimulation to standard wound care for pressure injuries. Methods We conducted a systematic search for studies published to December 7, 2016, limited to randomized and non–randomized controlled trials examining the effectiveness of electrical stimulation plus standard wound care versus standard wound care alone for patients with pressure injuries. We assessed the quality of evidence through Grading of Recommendations Assessment, Development, and Evaluation (GRADE). In addition, we conducted an economic literature review and a budget impact analysis to assess the cost-effectiveness and affordability of electrical stimulation for treatment of pressure ulcers in Ontario. Given uncertainties in clinical evidence and resource use, we did not conduct a primary economic evaluation. Finally, we conducted qualitative interviews with patients and caregivers about their experiences with pressure injuries, currently available treatments, and (if applicable) electrical stimulation. Results Nine randomized controlled trials and two non–randomized controlled trials were found from the systematic search. There was no significant difference in complete pressure injury healing between adjunct electrical stimulation and standard wound care. There was a significant difference in wound surface area reduction favouring electrical stimulation compared with standard wound care. The only study on cost-effectiveness of electrical stimulation was partially applicable to the patient population of interest. Therefore, the cost-effectiveness of electrical stimulation cannot be determined. We estimate that the cost of publicly funding electrical stimulation for pressure injuries would be $0.77 to $3.85 million yearly for the next 5 years. Patients and caregivers reported that pressure injuries were burdensome and reduced their quality of life. Patients and caregivers also noted that electrical stimulation seemed to reduce the time it took the wounds to heal. Conclusions While electrical stimulation is safe to use (GRADE quality of evidence: high) there is uncertainty about whether it improves wound healing (GRADE quality of evidence: low). In Ontario, publicly funding electrical stimulation for pressure injuries could result in extra costs of $0.77 to $3.85 million yearly for the next 5 years. PMID:29201261

A Randomized Clinical Trial to Dismantle Components of Cognitive Processing Therapy for Posttraumatic Stress Disorder in Female Victims of Interpersonal Violence

ERIC Educational Resources Information Center

Resick, Patricia A.; Galovski, Tara E.; Uhlmansiek, Mary O'Brien; Scher, Christine D.; Clum, Gretchen A.; Young-Xu, Yinong

2008-01-01

The purpose of this experiment was to conduct a dismantling study of cognitive processing therapy in which the full protocol was compared with its constituent components--cognitive therapy only (CPT-C) and written accounts (WA)--for the treatment of posttraumatic stress disorder (PTSD) and comorbid symptoms. The intent-to-treat (ITT) sample…

Effects of Project, Inquiry and Lecture-Demonstration Teaching Methods on Senior Secondary Students' Achievement in Separation of Mixtures Practical Test

ERIC Educational Resources Information Center

Sola, Agboola Omowunmi; Ojo, Oloyede Ezekiel

2007-01-01

This study assessed and compared the relative effectiveness of three methods for teaching and conducting experiments in separation of mixtures in chemistry. A pre-test, post-test experimental design with a control group was used. Two hundred and thirty three randomly selected Senior Secondary School I (SSS I) chemistry students were drawn from…

The Effects of Response Modes and Cues on Language Learning, Cognitive Load and Self-Efficacy Beliefs in Web-Based Learning

ERIC Educational Resources Information Center

Chen, Ching-Huei; Huang, Kun

2014-01-01

An experiment was conducted to examine how different response modes for practice questions and the presence or absence of cues influenced students' self-efficacy beliefs, perceived cognitive load, and performance in language recall and recognition tasks. One hundred fifty-seven 6th grade students were randomly assigned to one of four conditions:…

A Study of Student Opinion Toward Legal Needs and Interests. Office of Student Affairs Research Bulletin, Vol. 16, No. 7.

ERIC Educational Resources Information Center

Matross, Ronald; DeGidio, Carmen

A survey was conducted of the opinions of 393 randomly selected Twin Cities campus students toward student legal needs and interests. Key findings include: students have had extensive experience in their contact with legal transactions. Seventy-two percent have signed a contract, 66 percent have bought a car. Sixty-five percent stated they had at…

Comparative Effectiveness of Houghton Mifflin Harcourt Fuse: Algebra 1--A Report of Randomized Experiments in Four California Districts

ERIC Educational Resources Information Center

Toby, Megan; Ma, Boya; Lai, Garrett; Lin, Li; Jaciw, Andrew

2012-01-01

In spring 2010, Houghton Mifflin Harcourt (HMH) began planning a pilot of an application for the Apple iPad, "HMH Fuse: Algebra 1," which was then in development. The application was to be piloted in four California school districts during the 2010-2011 school year. HMH contracted with Empirical Education Inc. to conduct a one-year…

Experimental Evidence on the Effects of Home Computers on Academic Achievement among Schoolchildren. National Poverty Center Working Paper Series #13-02

ERIC Educational Resources Information Center

Fairlie, Robert W.; Robinson, Jonathan

2013-01-01

Computers are an important part of modern education, yet large segments of the population--especially low-income and minority children--lack access to a computer at home. Does this impede educational achievement? We test this hypothesis by conducting the largest-ever field experiment involving the random provision of free computers for home use to…

A "Politically Robust" Experimental Design for Public Policy Evaluation, with Application to the Mexican Universal Health Insurance Program

ERIC Educational Resources Information Center

King, Gary; Gakidou, Emmanuela; Ravishankar, Nirmala; Moore, Ryan T.; Lakin, Jason; Vargas, Manett; Tellez-Rojo, Martha Maria; Avila, Juan Eugenio Hernandez; Avila, Mauricio Hernandez; Llamas, Hector Hernandez

2007-01-01

We develop an approach to conducting large-scale randomized public policy experiments intended to be more robust to the political interventions that have ruined some or all parts of many similar previous efforts. Our proposed design is insulated from selection bias in some circumstances even if we lose observations; our inferences can still be…

WWC Review of the Report "Learning the Control of Variables Strategy in Higher and Lower Achieving Classrooms: Contributions of Explicit Instruction and Experimentation"

ERIC Educational Resources Information Center

What Works Clearinghouse, 2012

2012-01-01

The study reviewed in this paper examined three separate methods for teaching the "control of variables strategy" ("CVS"), a procedure for conducting a science experiment so that only one variable is tested and all others are held constant, or "controlled." The study analyzed data from a randomized controlled trial of…

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.

Apker Award Recipient: Renormalization-Group Study of Helium Mixtures Immersed in a Porous Medium

NASA Astrophysics Data System (ADS)

Lopatnikova, Anna

1998-03-01

Superfluidity and phase separation in ^3He-^4He mixtures immersed in aerogel are studied by renormalization-group theory. Firstly, the theory is applied to jungle-gym (non-random) aerogel.(A. Lopatnikova and A.N. Berker, Phys. Rev. B 55, 3798 (1997).) This calculation is conducted via the coupled renormalization-group mappings of interactions near and away from aerogel. Superfluidity at very low ^4He concentrations and a depressed tricritical temperature are found at the onset of superfludity. A superfluid-superfluid phase separation, terminating at an isolated critical point, is found entirely within the superfluid phase. Secondly, the theory is applied to true aerogel, which has quenched disorder at both atomic and geometric levels.(A. Lopatnikova and A.N. Berker, Phys. Rev. B 56, 11865 (1997).) This calculation is conducted via the coupled renormalization-group mappings, near and away from aerogel, of quenched probability distributions of random interactions. Random-bond effects on superfluidity onset and random-field effects on superfluid phase separation are seen. The quenched randomness causes the λ line of second-order phase transitions of superfluidity onset to reach zero temperature, in agreement with general prediction and experiments. Based on these studies, the experimentally observed(S.B. Kim, J. Ma, and M.H.W. Chan, Phys. Rev. Lett. 71, 2268 (1993); N. Mulders and M.H.W. Chan, Phys. Rev. Lett. 75, 3705 (1995).) distinctive characteristics of ^3He-^4He mixtures in aerogel are related to the aerogel properties of connectivity, tenuousness, and atomic and geometric randomness.

Testing the implementation and sustainment facilitation (ISF) strategy as an effective adjunct to the Addiction Technology Transfer Center (ATTC) strategy: study protocol for a cluster randomized trial.

PubMed

Garner, Bryan R; Zehner, Mark; Roosa, Mathew R; Martino, Steve; Gotham, Heather J; Ball, Elizabeth L; Stilen, Patricia; Speck, Kathryn; Vandersloot, Denna; Rieckmann, Traci R; Chaple, Michael; Martin, Erika G; Kaiser, David; Ford, James H

2017-11-17

Improving the extent to which evidence-based practices (EBPs)-treatments that have been empirically shown to be efficacious or effective-are integrated within routine practice is a well-documented challenge across numerous areas of health. In 2014, the National Institute on Drug Abuse funded a type 2 effectiveness-implementation hybrid trial titled the substance abuse treatment to HIV Care (SAT2HIV) Project. Aim 1 of the SAT2HIV Project tests the effectiveness of a motivational interviewing-based brief intervention (MIBI) for substance use as an adjunct to usual care within AIDS service organizations (ASOs) as part of its MIBI Experiment. Aim 2 of the SAT2HIV Project tests the effectiveness of implementation and sustainment facilitation (ISF) as an adjunct to the Addiction Technology Transfer Center (ATTC) model for training staff in motivational interviewing as part of its ISF Experiment. The current paper describes the study protocol for the ISF Experiment. Using a cluster randomized design, case management and leadership staff from 39 ASOs across the United States were randomized to receive either the ATTC strategy (control condition) or the ATTC + ISF strategy (experimental condition). The ATTC strategy is staff-focused and includes 10 discrete strategies (e.g., provide centralized technical assistance, conduct educational meetings, provide ongoing consultation). The ISF strategy is organization-focused and includes seven discrete strategies (e.g., use an implementation advisor, organize implementation team meetings, conduct cyclical small tests of change). Building upon the exploration-preparation-implementation-sustainment (EPIS) framework, the effectiveness of the ISF strategy is examined via three staff-level measures: (1) time-to-proficiency (i.e., preparation phase outcome), (2) implementation effectiveness (i.e., implementation phase outcome), and (3) level of sustainment (i.e., sustainment phase outcome). Although not without limitations, the ISF experiment has several strengths: a highly rigorous design (randomized, hypothesis-driven), high-need setting (ASOs), large sample size (39 ASOs), large geographic representation (23 states and the District of Columbia), and testing along multiple phases of the EPIS continuum (preparation, implementation, and sustainment). Thus, study findings will significantly improve generalizable knowledge regarding the best preparation, implementation, and sustainment strategies for advancing EBPs along the EPIS continuum. Moreover, increasing ASO's capacity to address substance use may improve the HIV Care Continuum. Trial registration ClinicalTrials.gov: NCT03120598.

Gene flow from transgenic common beans expressing the bar gene.

PubMed

Faria, Josias C; Carneiro, Geraldo E S; Aragão, Francisco J L

2010-01-01

Gene flow is a common phenomenon even in self-pollinated plant species. With the advent of genetically modified plants this subject has become of the utmost importance due to the need for controlling the spread of transgenes. This study was conducted to determine the occurrence and intensity of outcrossing in transgenic common beans. In order to evaluate the outcross rates, four experiments were conducted in Santo Antonio de Goiás (GO, Brazil) and one in Londrina (PR, Brazil), using transgenic cultivars resistant to the herbicide glufosinate ammonium and their conventional counterparts as recipients of the transgene. Experiments with cv. Olathe Pinto and the transgenic line Olathe M1/4 were conducted in a completely randomized design with ten replications for three years in one location, whereas the experiments with cv. Pérola and the transgenic line Pérola M1/4 were conducted at two locations for one year, with the transgenic cultivar surrounded on all sides by the conventional counterpart. The outcross occurred at a negligible rate of 0.00741% in cv. Pérola, while none was observed (0.0%) in cv. Olathe Pinto. The frequency of gene flow was cultivar dependent and most of the observed outcross was within 2.5 m from the edge of the pollen source. Index terms: Phaseolus vulgaris, outcross, glufosinate ammonium.

Ethical Considerations for Conducting Health Disparities Research in Community Health Centers: A Social-Ecological Perspective

PubMed Central

Scott, Ebony; Melendez, Jennifer; Rodriguez, Anna; Ramos, Rosio; Kanna, Balavenkatesh; Michelen, Walid

2013-01-01

Community health centers (CHCs) provide optimal research settings. They serve a high-risk, medically underserved population in the greatest need of intervention. Low socioeconomic status renders this population particularly vulnerable to research misconduct. Traditional principles of research ethics are often applied to participants only. The social-ecological model offers a comprehensive framework for applying these principles across multiple levels (participants, providers, organizations, communities, and policy). Our experience with the Trial Using Motivational Interviewing, Positive Affect and Self-Affirmation in African-Americans with Hypertension, a randomized trial conducted in CHCs, led us to propose a new platform for discussing research ethics; examine the social, community, and political factors surrounding research conducted in CHCs; and recommend how future research should be conducted in such settings. PMID:24134347

Ethical considerations for conducting health disparities research in community health centers: a social-ecological perspective.

PubMed

Boutin-Foster, Carla; Scott, Ebony; Melendez, Jennifer; Rodriguez, Anna; Ramos, Rosio; Kanna, Balavenkatesh; Michelen, Walid

2013-12-01

Community health centers (CHCs) provide optimal research settings. They serve a high-risk, medically underserved population in the greatest need of intervention. Low socioeconomic status renders this population particularly vulnerable to research misconduct. Traditional principles of research ethics are often applied to participants only. The social-ecological model offers a comprehensive framework for applying these principles across multiple levels (participants, providers, organizations, communities, and policy). Our experience with the Trial Using Motivational Interviewing, Positive Affect and Self-Affirmation in African-Americans with Hypertension, a randomized trial conducted in CHCs, led us to propose a new platform for discussing research ethics; examine the social, community, and political factors surrounding research conducted in CHCs; and recommend how future research should be conducted in such settings.

Identifying sensitive areas of adaptive observations for prediction of the Kuroshio large meander using a shallow-water model

NASA Astrophysics Data System (ADS)

Zou, Guang'an; Wang, Qiang; Mu, Mu

2016-09-01

Sensitive areas for prediction of the Kuroshio large meander using a 1.5-layer, shallow-water ocean model were investigated using the conditional nonlinear optimal perturbation (CNOP) and first singular vector (FSV) methods. A series of sensitivity experiments were designed to test the sensitivity of sensitive areas within the numerical model. The following results were obtained: (1) the eff ect of initial CNOP and FSV patterns in their sensitive areas is greater than that of the same patterns in randomly selected areas, with the eff ect of the initial CNOP patterns in CNOP sensitive areas being the greatest; (2) both CNOP- and FSV-type initial errors grow more quickly than random errors; (3) the eff ect of random errors superimposed on the sensitive areas is greater than that of random errors introduced into randomly selected areas, and initial errors in the CNOP sensitive areas have greater eff ects on final forecasts. These results reveal that the sensitive areas determined using the CNOP are more sensitive than those of FSV and other randomly selected areas. In addition, ideal hindcasting experiments were conducted to examine the validity of the sensitive areas. The results indicate that reduction (or elimination) of CNOP-type errors in CNOP sensitive areas at the initial time has a greater forecast benefit than the reduction (or elimination) of FSV-type errors in FSV sensitive areas. These results suggest that the CNOP method is suitable for determining sensitive areas in the prediction of the Kuroshio large-meander path.

Concepts for a theoretical and experimental study of lifting rotor random loads and vibrations (further experiments with progressing/regressing rotor flapping modes), Phase 7-C

NASA Technical Reports Server (NTRS)

Hohenemser, K. H.; Crews, S. T.

1973-01-01

The experiments with progressing/regressing forced rotor flapping modes have been extended in several directions and the data processing method has been considerably refined. The 16 inch hingeless 2-bladed rotor model was equipped with a new set of high precision blades which removed previously encountered tracking difficulties at high advance ratio, so that tests up to .8 rotor advance ratio could be conducted. In addition to data with 1.20 blade natural flapping frequency data at 1.10 flapping frequency were obtained. Outside the wind tunnel, tests with a ground plate located at different distances below the rotor were conducted while recording the dynamic downflow at a station .2R below the rotor plane with a hot wire anemometer.

Conductivity of Nanowire Arrays under Random and Ordered Orientation Configurations

PubMed Central

Jagota, Milind; Tansu, Nelson

2015-01-01

A computational model was developed to analyze electrical conductivity of random metal nanowire networks. It was demonstrated for the first time through use of this model that a performance gain in random metal nanowire networks can be achieved by slightly restricting nanowire orientation. It was furthermore shown that heavily ordered configurations do not outperform configurations with some degree of randomness; randomness in the case of metal nanowire orientations acts to increase conductivity. PMID:25976936

Lessons from the field: the conduct of randomized controlled trials in Botswana.

PubMed

Bonsu, Janice M; Frasso, Rosemary; Curry, Allison E

2017-10-27

The conduct of randomized controlled trials (RCTs) in low-resource settings may present unique financial, logistic, and process-related challenges. Middle-income countries that have comparable disease burdens to low-income countries, but greater availability of resources, may be conducive settings for RCTs. Indeed, the country of Botswana is experiencing a rapid increase in the conduct of RCTs. Our objective was to explore the experiences of individuals conducting RCTs in Botswana to gain an understanding of the challenges and adaptive strategies to their work. We conducted in-depth interviews with 14 national and international individuals working on RCTs in Botswana. Participants included principal investigators, research coordinators, lab technicians, research assistants, and other healthcare professionals. Interviews were audiotaped, transcribed verbatim, and coded for thematic analysis. Five primary themes were identified: ethics board relationships (including delays in the process); research staff management (including staff attrition and career development); study recruitment and retention (including the use of reimbursements); resource availability (including challenges accessing laboratory equipment); and capacity-building (including issues of exporting locally sourced samples). These themes were explored to discuss key challenges and adaptive strategies. This study offers a first-hand account of individuals engaged in conducting RCTs in Botswana, a nation that is experiencing a rapid increase in research activities. Findings provide a foundational understanding for researchers in Botswana and trial managers in similar settings when planning RCTs so that the conduct of research does not outpace the ability to manage, support, and regulate it.

Violence against women in the context of war: experiences of Shi'i women and Palestinian refugee women in Lebanon.

PubMed

Holt, Maria

2013-03-01

In times of war, women are likely to experience, in addition to the "normal" violence of peacetime, random cruelties perpetrated by the enemy against all members of the community. During research conducted with Palestinian refugees and Shi'i Muslims in Lebanon, women described various forms of violence and, in this article, I examine violence suffered by women in the context of conflict from three perspectives: victimization, trauma, and resistance. I argue that traumatic events have the effect of obliterating identity, but they can also strengthen the resolve to resist.

Text Summarization Model based on Maximum Coverage Problem and its Variant

NASA Astrophysics Data System (ADS)

Takamura, Hiroya; Okumura, Manabu

We discuss text summarization in terms of maximum coverage problem and its variant. To solve the optimization problem, we applied some decoding algorithms including the ones never used in this summarization formulation, such as a greedy algorithm with performance guarantee, a randomized algorithm, and a branch-and-bound method. We conduct comparative experiments. On the basis of the experimental results, we also augment the summarization model so that it takes into account the relevance to the document cluster. Through experiments, we showed that the augmented model is at least comparable to the best-performing method of DUC'04.

Design of Experiments for the Thermal Characterization of Metallic Foam

NASA Technical Reports Server (NTRS)

Crittenden, Paul E.; Cole, Kevin D.

2003-01-01

Metallic foams are being investigated for possible use in the thermal protection systems of reusable launch vehicles. As a result, the performance of these materials needs to be characterized over a wide range of temperatures and pressures. In this paper a radiation/conduction model is presented for heat transfer in metallic foams. Candidates for the optimal transient experiment to determine the intrinsic properties of the model are found by two methods. First, an optimality criterion is used to find an experiment to find all of the parameters using one heating event. Second, a pair of heating events is used to determine the parameters in which one heating event is optimal for finding the parameters related to conduction, while the other heating event is optimal for finding the parameters associated with radiation. Simulated data containing random noise was analyzed to determine the parameters using both methods. In all cases the parameter estimates could be improved by analyzing a larger data record than suggested by the optimality criterion.

A Short History of Randomized Experiments in Criminology: A Meager Feast.

ERIC Educational Resources Information Center

Farrington, David P.

2003-01-01

Discusses advantages of randomized experiments and key issues raised in this special issue. Focuses on growth and decrease in the use of randomized experiments by the California Youth Authority, the U.S. National Institute of Justice, and the British Home Office. Calls for increased recognition of the importance of randomized experiments. (SLD)

A randomized controlled trial of smartphone-based mindfulness training for smoking cessation: a study protocol.

PubMed

Garrison, Kathleen A; Pal, Prasanta; Rojiani, Rahil; Dallery, Jesse; O'Malley, Stephanie S; Brewer, Judson A

2015-04-14

Tobacco use is responsible for the death of about 1 in 10 individuals worldwide. Mindfulness training has shown preliminary efficacy as a behavioral treatment for smoking cessation. Recent advances in mobile health suggest advantages to smartphone-based smoking cessation treatment including smartphone-based mindfulness training. This study evaluates the efficacy of a smartphone app-based mindfulness training program for improving smoking cessation rates at 6-months follow-up. A two-group parallel-randomized clinical trial with allocation concealment will be conducted. Group assignment will be concealed from study researchers through to follow-up. The study will be conducted by smartphone and online. Daily smokers who are interested in quitting smoking and own a smartphone (n = 140) will be recruited through study advertisements posted online. After completion of a baseline survey, participants will be allocated randomly to the control or intervention group. Participants in both groups will receive a 22-day smartphone-based treatment program for smoking. Participants in the intervention group will receive mobile mindfulness training plus experience sampling. Participants in the control group will receive experience sampling-only. The primary outcome measure will be one-week point prevalence abstinence from smoking (at 6-months follow-up) assessed using carbon monoxide breath monitoring, which will be validated through smartphone-based video chat. This is the first intervention study to evaluate smartphone-based delivery of mindfulness training for smoking cessation. Such an intervention may provide treatment in-hand, in real-world contexts, to help individuals quit smoking. Clinicaltrials.gov NCT02134509 . Registered 7 May 2014.

Instructor feedback versus no instructor feedback on performance in a laparoscopic virtual reality simulator: a randomized educational trial.

PubMed

Oestergaard, Jeanett; Bjerrum, Flemming; Maagaard, Mathilde; Winkel, Per; Larsen, Christian Rifbjerg; Ringsted, Charlotte; Gluud, Christian; Grantcharov, Teodor; Ottesen, Bent; Soerensen, Jette Led

2012-02-28

Several studies have found a positive effect on the learning curve as well as the improvement of basic psychomotor skills in the operating room after virtual reality training. Despite this, the majority of surgical and gynecological departments encounter hurdles when implementing this form of training. This is mainly due to lack of knowledge concerning the time and human resources needed to train novice surgeons to an adequate level. The purpose of this trial is to investigate the impact of instructor feedback regarding time, repetitions and self-perception when training complex operational tasks on a virtual reality simulator. The study population consists of medical students on their 4th to 6th year without prior laparoscopic experience. The study is conducted in a skills laboratory at a centralized university hospital. Based on a sample size estimation 98 participants will be randomized to an intervention group or a control group. Both groups have to achieve a predefined proficiency level when conducting a laparoscopic salpingectomy using a surgical virtual reality simulator. The intervention group receives standardized instructor feedback of 10 to 12 min a maximum of three times. The control group receives no instructor feedback. Both groups receive the automated feedback generated by the virtual reality simulator. The study follows the CONSORT Statement for randomized trials. Main outcome measures are time and repetitions to reach the predefined proficiency level on the simulator. We include focus on potential sex differences, computer gaming experience and self-perception. The findings will contribute to a better understanding of optimal training methods in surgical education. NCT01497782.

Comparative Effectiveness of Houghton Mifflin Harcourt Fuse: Algebra 1--A Report of Randomized Experiments in Four California Districts. Research Summary

ERIC Educational Resources Information Center

Empirical Education Inc., 2012

2012-01-01

In spring 2010, Houghton Mifflin Harcourt (HMH) began planning a pilot of an application for the Apple iPad, "HMH Fuse: Algebra 1," which was then in development. The application was to be piloted in four California school districts during the 2010-2011 school year. HMH contracted with Empirical Education Inc. to conduct a one-year…

Material hardship and children's social-emotional development: Testing mitigating effects of Child Development Accounts in a randomized experiment.

PubMed

Huang, J; Kim, Y; Sherraden, M

2017-01-01

Research has established a negative association between household material hardship and children's mental health. This study examines whether Child Development Accounts (CDAs), an economic intervention that encourages families to accumulate assets for children's long-term development, mitigate the association between material hardship and children's social-emotional development. Researchers conducted a randomized experiment of CDAs in Oklahoma, USA, with a probability sample (N = 7328) of all infants born in two 3-month periods in 2007. After agreeing to participate in the experiment, caregivers of 2704 infants completed a baseline survey and were assigned randomly to the treatment (n = 1358) or control group (n = 1346). The intervention exposed the treatment group to a CDA, which consisted of an Oklahoma 529 College Savings Plan account, financial incentives and financial information. Material hardship has a negative association with the social-emotional development of children around the age of 4 years. Estimates from regression analysis indicate that CDAs mitigate about 50% of the negative association between material hardship and children's social-emotional development. Although they do not provide direct support for consumption in households experiencing material hardship, CDAs may improve child development by influencing parenting practices and parents' expectations for their children. We discuss the implications of using asset-building programmes to improve child development. © 2016 John Wiley & Sons Ltd.

Cardiac examination and the effect of dual-processing instruction in a cardiopulmonary simulator.

PubMed

Sibbald, Matt; McKinney, James; Cavalcanti, Rodrigo B; Yu, Eric; Wood, David A; Nair, Parvathy; Eva, Kevin W; Hatala, Rose

2013-08-01

Use of dual-processing has been widely touted as a strategy to reduce diagnostic error in clinical medicine. However, this strategy has not been tested among medical trainees with complex diagnostic problems. We sought to determine whether dual-processing instruction could reduce diagnostic error across a spectrum of experience with trainees undertaking cardiac physical exam. Three experiments were conducted using a similar design to teach cardiac physical exam using a cardiopulmonary simulator. One experiment was conducted in each of three groups: experienced, intermediate and novice trainees. In all three experiments, participants were randomized to receive undirected or dual-processing verbal instruction during teaching, practice and testing phases. When tested, dual-processing instruction did not change the probability assigned to the correct diagnosis in any of the three experiments. Among intermediates, there was an apparent interaction between the diagnosis tested and the effect of dual-processing instruction. Among relative novices, dual processing instruction may have dampened the harmful effect of a bias away from the correct diagnosis. Further work is needed to define the role of dual-processing instruction to reduce cognitive error. This study suggests that it cannot be blindly applied to complex diagnostic problems such as cardiac physical exam.

Coarsening in Solid-liquid Mixtures: Overview of Experiments on Shuttle and ISS

NASA Technical Reports Server (NTRS)

Duval, Walter M. B.; Hawersaat, Robert W.; Lorik, T.; Thompson, J.; Gulsoy, B.; Voorhees, P. W.

2013-01-01

The microgravity environment on the Shuttle and the International Space Station (ISS) provides the ideal condition to perform experiments on Coarsening in Solid-Liquid Mixtures (CSLM) as deleterious effects such as particle sedimentation and buoyancy-induced convection are suppressed. For an ideal system such as Lead-Tin in which all the thermophysical properties are known, the initial condition in microgravity of randomly dispersed particles with local clustering of solid Tin in eutectic liquid Lead-Tin matrix, permitted kinetic studies of competitive particle growth for a range of volume fractions. Verification that the quenching phase of the experiment had negligible effect of the spatial distribution of particles is shown through the computational solution of the dynamical equations of motion, thus insuring quench-free effects from the coarsened microstructure measurements. The low volume fraction experiments conducted on the Shuttle showed agreement with transient Ostwald ripening theory, and the steady-state requirement of LSW theory was not achieved. More recent experiments conducted on ISS with higher volume fractions have achieved steady-state condition and show that the kinetics follows the classical diffusion limited particle coarsening prediction and the measured 3D particle size distribution becomes broader as predicted from theory.

Pain following foraminal enlargement in mandibular molars with necrosis and apical periodontitis: A randomized controlled trial.

PubMed

Saini, H R; Sangwan, P; Sangwan, A

2016-12-01

This randomized controlled trial was conducted to evaluate the effect of foraminal enlargement during chemomechanical root canal preparation on postoperative pain. Seventy mandibular first molars with asymptomatic pulp necrosis and chronic apical periodontitis were randomized into two groups - foraminal enlargement (FE) and conventional nonforaminal enlargement (NFE). Canals were prepared according to the respective protocols, and the teeth were restored temporarily. Postoperatively, the patients were prescribed ibuprofen 400 mg, to be taken if required. Pain experience and analgesic intake were recorded for 7 days following chemomechanical preparation. The data were analysed using Mann-Whitney U-test and chi-square tests. Pain experience was higher with foraminal enlargement than when using a conventional technique. A significant difference was observed in postoperative pain during the first 4 days and the sixth day (P < 0.05), with greater pain in the FE as compared to the NFE group. There was no significant difference in prevalence of analgesic intake and number of doses between the experimental groups (P > 0.05). Enlargement of the apical foramen during root canal treatment increased the incidence and intensity of postoperative pain. © 2015 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Changes in work affect in response to lunchtime walking in previously physically inactive employees: A randomized trial.

PubMed

Thøgersen-Ntoumani, C; Loughren, E A; Kinnafick, F-E; Taylor, I M; Duda, J L; Fox, K R

2015-12-01

Physical activity may regulate affective experiences at work, but controlled studies are needed and there has been a reliance on retrospective accounts of experience. The purpose of the present study was to examine the effect of lunchtime walks on momentary work affect at the individual and group levels. Physically inactive employees (N = 56; M age = 47.68; 92.86% female) from a large university in the UK were randomized to immediate treatment or delayed treatment (DT). The DT participants completed both a control and intervention period. During the intervention period, participants partook in three weekly 30-min lunchtime group-led walks for 10 weeks. They completed twice daily affective reports at work (morning and afternoon) using mobile phones on two randomly chosen days per week. Multilevel modeling was used to analyze the data. Lunchtime walks improved enthusiasm, relaxation, and nervousness at work, although the pattern of results differed depending on whether between-group or within-person analyses were conducted. The intervention was effective in changing some affective states and may have broader implications for public health and workplace performance. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Provider Training to Screen and Initiate Evidence-Based Pediatric Obesity Treatment in Routine Practice Settings: A Randomized Pilot Trial.

PubMed

Kolko, Rachel P; Kass, Andrea E; Hayes, Jacqueline F; Levine, Michele D; Garbutt, Jane M; Proctor, Enola K; Wilfley, Denise E

This randomized pilot trial evaluated two training modalities for first-line, evidence-based pediatric obesity services (screening and goal setting) among nursing students. Participants (N = 63) were randomized to live interactive training or Web-facilitated self-study training. Pretraining, post-training, and 1-month follow-up assessments evaluated training feasibility, acceptability, and impact (knowledge and skill via simulation). Moderator (previous experience) and predictor (content engagement) analyses were conducted. Nearly all participants (98%) completed assessments. Both types of training were acceptable, with higher ratings for live training and participants with previous experience (ps < .05). Knowledge and skill improved from pretraining to post-training and follow-up in both conditions (ps < .001). Live training demonstrated greater content engagement (p < .01). The training package was feasible, acceptable, and efficacious among nursing students. Given that live training had higher acceptability and engagement and online training offers greater scalability, integrating interactive live training components within Web-based training may optimize outcomes, which may enhance practitioners' delivery of pediatric obesity services. Copyright © 2016 National Association of Pediatric Nurse Practitioners. Published by Elsevier Inc. All rights reserved.

Hypersonic Wind Tunnel Calibration Using the Modern Design of Experiments

NASA Technical Reports Server (NTRS)

Rhode, Matthew N.; DeLoach, Richard

2005-01-01

A calibration of a hypersonic wind tunnel has been conducted using formal experiment design techniques and response surface modeling. Data from a compact, highly efficient experiment was used to create a regression model of the pitot pressure as a function of the facility operating conditions as well as the longitudinal location within the test section. The new calibration utilized far fewer design points than prior experiments, but covered a wider range of the facility s operating envelope while revealing interactions between factors not captured in previous calibrations. A series of points chosen randomly within the design space was used to verify the accuracy of the response model. The development of the experiment design is discussed along with tactics used in the execution of the experiment to defend against systematic variation in the results. Trends in the data are illustrated, and comparisons are made to earlier findings.

Thermally Cross-Linked Anion Exchange Membranes from Solvent Processable Isoprene Containing Ionomers

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

Tsai, Tsung-Han; Ertem, S. Piril; Maes, Ashley M.

2015-01-28

Random copolymers of isoprene and 4-vinylbenzyl chloride (VBCl) with varying compositions were synthesized via nitroxide-mediated polymerization. Subsequent quaternization afforded solvent processable and cross-linkable ionomers with a wide range of ion exchange capacities (IECs). Solution cast membranes were thermally cross-linked to form anion exchange membranes. Cross-linking was achieved by taking advantage of the unsaturations on the polyisoprene backbone, without added cross-linkers. A strong correlation was found between water uptake and ion conductivity of the membranes: conductivities of the membranes with IECs beyond a critical value were found to be constant related to their high water absorption. Environmentally controlled small-angle X-ray scatteringmore » experiments revealed a correlation between the average distance between ionic clusters and the ion conductivity, indicating that a well-connected network of ion clusters is necessary for efficient ion conduction and high ion conductivity.« less

[Association between adverse experiences in childhood and risk of chronic diseases in adulthood].

PubMed

Nie, Junyan; Yu, Honghui; Wang, Zhiqiang; Wang, Leilei; Han, Juan; Wang, Youjie; Du, Yukai; Shen, Min

2015-09-01

To analyze the prevalence and characteristics of childhood adverse experiences among adults aged 18-59 years and understand the association between childhood adverse experiences and risk of chronic diseases in adulthood. A cross-sectional study was conducted with a questionnaire among adults aged 18-59 years selected through cluster random sampling from 3 communities in Macheng, Hubei province. Uinivariate and multivariate logistic regression analyses were conducted to evaluate the association between adverse experiences in childhood and the risk of chronic diseases in adulthood. A total of 1 767 adults aged 18-59 years were surveyed and 1 501 valid questionnaires were returned. The average age was (36.32± 10.20) years for males and (35.72±9.08) years for females. The prevalence rate of childhood adverse experiences was 66.22%. The risk of chronic disease in adults increased with the increase of the score indicating childhood adverse experiences (Z=-5.902 1, P<0.000 1). Multivariate logistic regression analysis showed that being physically abused (OR=1.93, 95% CI: 1.41-2.64), substance abuse in family (OR=2.82, 95% CI: 1.16-6.80), being bullied (OR=2.59, 95% CI: 1.39-4.80) and parents separation/divorce (OR=1.51, 95% CI: 1.09-2.09) were significantly associated with risk of chronic diseases in adulthood. The prevalence of adverse childhood experiences was high in adults aged 18-59 years, which was significantly associated with the risk of chronic diseases in adulthood. Early prevention of chronic diseases should be conducted in childhood.

Recruiting participants with peripheral arterial disease for clinical trials: experience from the Study to Improve Leg Circulation (SILC).

PubMed

McDermott, Mary M; Domanchuk, Kathryn; Dyer, Alan; Ades, Philip; Kibbe, Melina; Criqui, Michael H

2009-03-01

To describe the success of diverse recruitment methods in a randomized controlled clinical trial of exercise in persons with peripheral arterial disease (PAD). An analysis of recruitment sources conducted for the 746 men and women completing a baseline visit for the study to improve leg circulation (SILC), a randomized controlled trial of exercise for patients with PAD. For each recruitment source, we determined the number of randomized participants, the rate of randomization among those completing a baseline visit, and cost per randomized participant. Of the 746 individuals who completed a baseline visit, 156 were eligible and randomized. The most frequent sources of randomized participants were newspaper advertising (n = 67), mailed recruitment letters to patients with PAD identified at the study medical center (n = 25), and radio advertising (n = 18). Costs per randomized participant were $2750 for television advertising, $2167 for Life Line Screening, $2369 for newspaper advertising, $3931 for mailed postcards to older community dwelling men and women, and $5691 for radio advertising. Among those completing a baseline visit, randomization rates ranged from 10% for those identified from radio advertising to 32% for those identified from the Chicago Veterans Administration and 33% for those identified from posted flyers. Most participants in a randomized controlled trial of exercise were recruited from newspaper advertising and mailed recruitment letters to patients with known PAD. The highest randomization rates after a baseline visit occurred among participants identified from posted flyers and mailed recruitment letters to PAD patients.

Effects of the amount and composition of the forest floor on emergence and early establishment of loblolly pine seedlings

Treesearch

Michael G. Shelton

1995-01-01

Five forest floor weights (0, 10, 20, 30, and 40 MgJha), three forest floor compositions (pine, pine-hardwood, and hardwood), and two seed placements (forest floor and soil surface) were tested in a three-factorial. split-plot design with four incomplete, randomized blocks. The experiment was conducted in a nursery setting and used wooden frames to define 0.145-m

Can training improve the quality of inferences made by raters in competency modeling? A quasi-experiment.

PubMed

Lievens, Filip; Sanchez, Juan I

2007-05-01

A quasi-experiment was conducted to investigate the effects of frame-of-reference training on the quality of competency modeling ratings made by consultants. Human resources consultants from a large consulting firm were randomly assigned to either a training or a control condition. The discriminant validity, interrater reliability, and accuracy of the competency ratings were significantly higher in the training group than in the control group. Further, the discriminant validity and interrater reliability of competency inferences were highest among an additional group of trained consultants who also had competency modeling experience. Together, these results suggest that procedural interventions such as rater training can significantly enhance the quality of competency modeling. 2007 APA, all rights reserved

Volitional personality trait change: Can people choose to change their personality traits?

PubMed

Hudson, Nathan W; Fraley, R Chris

2015-09-01

Previous research has found that most people want to change their personality traits. But can people actually change their personalities just because they want to? To answer this question, we conducted 2, 16-week intensive longitudinal randomized experiments. Across both studies, people who expressed goals to increase with respect to any Big Five personality trait at Time 1 tended to experience actual increases in their self-reports of that trait-as well as trait-relevant daily behavior-over the subsequent 16 weeks. Furthermore, we tested 2 randomized interventions designed to help participants attain desired trait changes. Although 1 of the interventions was inefficacious, a second intervention that trained participants to generate implementation intentions catalyzed their ability to attain trait changes. We also tested several theoretical processes through which volitional changes might occur. These studies suggest that people may be able to change their self-reported personality traits through volitional means, and represent a first step toward understanding the processes that enable people to do so. (c) 2015 APA, all rights reserved).

Mass discrimination during weightlessness

NASA Technical Reports Server (NTRS)

Ross, H.

1981-01-01

An experiment concerned with the ability of astronauts to discriminate between the mass of objects when both the objects and the astronauts are in weightless states is described. The main object of the experiment is to compare the threshold for weight-discrimination on Earth with that for mass-discrimination in orbit. Tests will be conducted premission and postmission and early and late during the mission while the crew is experiencing weightlessness. A comparison of early and late tests inflight and postflight will reveal the rate of adaptation to zero-gravity and 1-g. The mass discrimination box holds 24 balls which the astronaut will compare to one another in a random routine.

The efficacy of sugar labeling formats: Implications for labeling policy.

PubMed

Vanderlee, Lana; White, Christine M; Bordes, Isabelle; Hobin, Erin P; Hammond, David

2015-12-01

To examine knowledge of sugar recommendations and test the efficacy of formats for labeling total and added sugar on pre-packaged foods. Online surveys were conducted among 2008 Canadians aged 16-24. Participants were asked to identify recommended limits for total and added sugar consumption. In Experiment 1, participants were randomized to one of six labeling conditions with varying information for total sugar for a high- or low-sugar product and were asked to identify the relative amount of total sugar in the product. In Experiment 2, participants were randomized to one of three labels with different added sugar formats and were asked if the product contained added sugar and the relative amount of added sugar. Few young people correctly identified recommendations for total sugar (5%) or added sugar (7%). In Experiment 1, those who were shown percent daily value information were more likely to correctly identify the relative amount of total sugar (P < 0.05). In Experiment 2, those shown added sugar information were more likely to correctly identify that the product contained added sugar and the relative amount of added sugar in the product (P < 0.05). Improved labeling may improve consumer understanding of the amount of sugars in food products. © 2015 The Obesity Society.

Laboratory experiment of seismic cycles using compliant viscoelastic materials

NASA Astrophysics Data System (ADS)

Yamaguchi, T.

2016-12-01

It is well known that surface asperities at fault interfaces play an essential role in stick-slip friction. There have been many laboratory experiments conducted using rocks and some analogue materials to understand the effects of asperities and the underlying mechanisms. Among such materials, soft polymer gels have great advantages of slowing down propagating rupture front speed as well as shear wave speed: it facilitates observation of the dynamic rupture behavior. However, most experiments were done with bimaterial interfaces (combination of soft and hard materials) and there are few experiments with an identical (gel on gel) setup. Furthermore, there have been also few studies mentioning the link between local asperity contact and macroscopic dynamic rupture behavior. In this talk, we report our experimental studies on stick-slip friction between gels having controlled artificial asperities. We show that, depending on number density and configuration randomness of the asperities, the rupture behavior greatly changes: when the asperities are located periodically with optimum number densities, fast rupture propagation occurs, while slow and heterogeneous slip behavior is observed for samples having randomly located asperities. We discuss the importance of low frequency (large wavelength) excitation of the normal displacement contributing to weakening the fault interface. We also discuss the observed regular to slow slip transition with a simple model.

Existence of the Harmonic Measure for Random Walks on Graphs and in Random Environments

NASA Astrophysics Data System (ADS)

Boivin, Daniel; Rau, Clément

2013-01-01

We give a sufficient condition for the existence of the harmonic measure from infinity of transient random walks on weighted graphs. In particular, this condition is verified by the random conductance model on ℤ d , d≥3, when the conductances are i.i.d. and the bonds with positive conductance percolate. The harmonic measure from infinity also exists for random walks on supercritical clusters of ℤ2. This is proved using results of Barlow (Ann. Probab. 32:3024-3084, 2004) and Barlow and Hambly (Electron. J. Probab. 14(1):1-27, 2009).

Effects of temperature and photoperiod on postponing bermudagrass (Cynodon dactylon [L.] Pers.) turf dormancy.

PubMed

Esmaili, Somayeh; Salehi, Hassan

2012-06-15

Growth chamber and field experiments were carried out to determine the effects of extended photoperiod under low and freezing temperatures on bermudagrass turf dormancy at Bajgah, in the southern part of Iran. The experiment in the growth chamber was conducted with four temperature regimes (15, 7.5, 0 and -7.5°C) and three light durations (8, 12 and 16h) in a completely randomized design with four replications. The field study was conducted in two consecutive years (2008-2009) with three light durations (8, 12 and 16h) in months with natural short day length and arranged in a randomized complete blocks design with three replications. Results in both experiments showed that decreasing temperature and photoperiod decreased verdure fresh and dry weight, shoot height, tiller density, leaf area and chlorophyll and relative water contents (RWC). However, rooting depth and fresh weight of roots increased in the growth chamber. Decreasing the temperature and light duration increased electrolyte leakage and proline content. Reducing sugars increased with decreasing temperature and declined with lowering light duration in both shoots and roots. Starch content of both shoots and roots showed an adverse trend compared to reducing sugars; starch content increased in both shoots and roots in all treatments by shortening the photoperiod. Practically, the problem of bermudagrass turf's dormancy could be solved via increasing the photoperiod in months with short day lengths. This treatment would be efficient and useful for turfgrass managers to apply in landscapes and stadiums. Copyright © 2012 Elsevier GmbH. All rights reserved.

HTR-PROTEUS PEBBLE BED EXPERIMENTAL PROGRAM CORE 4: RANDOM PACKING WITH A 1:1 MODERATOR-TO-FUEL PEBBLE RATIO

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

John D. Bess; Leland M. Montierth

2013-03-01

In its deployment as a pebble bed reactor (PBR) critical facility from 1992 to 1996, the PROTEUS facility was designated as HTR-PROTEUS. This experimental program was performed as part of an International Atomic Energy Agency (IAEA) Coordinated Research Project (CRP) on the Validation of Safety Related Physics Calculations for Low Enriched HTGRs. Within this project, critical experiments were conducted for graphite moderated LEU systems to determine core reactivity, flux and power profiles, reaction-rate ratios, the worth of control rods, both in-core and reflector based, the worth of burnable poisons, kinetic parameters, and the effects of moisture ingress on these parameters.more » One benchmark experiment was evaluated in this report: Core 4. Core 4 represents the only configuration with random pebble packing in the HTR-PROTEUS series of experiments, and has a moderator-to-fuel pebble ratio of 1:1. Three random configurations were performed. The initial configuration, Core 4.1, was rejected because the method for pebble loading, separate delivery tubes for the moderator and fuel pebbles, may not have been completely random; this core loading was rejected by the experimenters. Cores 4.2 and 4.3 were loaded using a single delivery tube, eliminating the possibility for systematic ordering effects. The second and third cores differed slightly in the quantity of pebbles loaded (40 each of moderator and fuel pebbles), stacked height of the pebbles in the core cavity (0.02 m), withdrawn distance of the stainless steel control rods (20 mm), and withdrawn distance of the autorod (30 mm). The 34 coolant channels in the upper axial reflector and the 33 coolant channels in the lower axial reflector were open. Additionally, the axial graphite fillers used in all other HTR-PROTEUS configurations to create a 12-sided core cavity were not used in the randomly packed cores. Instead, graphite fillers were placed on the cavity floor, creating a funnel-like base, to discourage ordering effects during pebble loading. Core 4 was determined to be acceptable benchmark experiment.« less

HTR-proteus pebble bed experimental program core 4: random packing with a 1:1 moderator-to-fuel pebble ratio

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

Bess, John D.; Montierth, Leland M.; Sterbentz, James W.

2014-03-01

In its deployment as a pebble bed reactor (PBR) critical facility from 1992 to 1996, the PROTEUS facility was designated as HTR-PROTEUS. This experimental program was performed as part of an International Atomic Energy Agency (IAEA) Coordinated Research Project (CRP) on the Validation of Safety Related Physics Calculations for Low Enriched HTGRs. Within this project, critical experiments were conducted for graphite moderated LEU systems to determine core reactivity, flux and power profiles, reaction-rate ratios, the worth of control rods, both in-core and reflector based, the worth of burnable poisons, kinetic parameters, and the effects of moisture ingress on these parameters.more » One benchmark experiment was evaluated in this report: Core 4. Core 4 represents the only configuration with random pebble packing in the HTR-PROTEUS series of experiments, and has a moderator-to-fuel pebble ratio of 1:1. Three random configurations were performed. The initial configuration, Core 4.1, was rejected because the method for pebble loading, separate delivery tubes for the moderator and fuel pebbles, may not have been completely random; this core loading was rejected by the experimenters. Cores 4.2 and 4.3 were loaded using a single delivery tube, eliminating the possibility for systematic ordering effects. The second and third cores differed slightly in the quantity of pebbles loaded (40 each of moderator and fuel pebbles), stacked height of the pebbles in the core cavity (0.02 m), withdrawn distance of the stainless steel control rods (20 mm), and withdrawn distance of the autorod (30 mm). The 34 coolant channels in the upper axial reflector and the 33 coolant channels in the lower axial reflector were open. Additionally, the axial graphite fillers used in all other HTR-PROTEUS configurations to create a 12-sided core cavity were not used in the randomly packed cores. Instead, graphite fillers were placed on the cavity floor, creating a funnel-like base, to discourage ordering effects during pebble loading. Core 4 was determined to be acceptable benchmark experiment.« less

Dealing with daily challenges in dementia (deal-id study): effectiveness of the experience sampling method intervention 'Partner in Sight' for spousal caregivers of people with dementia: design of a randomized controlled trial.

PubMed

van Knippenberg, Rosalia J M; de Vugt, Marjolein E; Ponds, Rudolf W; Myin-Germeys, Inez; Verhey, Frans R J

2016-05-11

There is an urgent need for psychosocial interventions that effectively support dementia caregivers in daily life. The Experience Sampling Methodology (ESM) offers the possibility to provide a more dynamic view of caregiver functioning. ESM-derived feedback may help to redirect caregivers' behavior towards situations that elicit positive emotions and to increase their feelings of competence in the caretaking process. This paper presents the design of a study that evaluates the process characteristics and effects of the ESM-based intervention 'Partner in Sight'. A randomized controlled trial with 90 spousal caregivers of people with dementia will be conducted. Participants will be randomly assigned to the experimental (6-week ESM intervention including feedback), pseudo-experimental (6-week ESM intervention without feedback), or control group (care as usual). Assessments will be performed pre- and post-intervention and at 2-, and 6-month follow-up. Main outcomes will be sense of competence, perceived control, momentary positive affect, and psychological complaints (depressive symptoms, perceived stress, anxiety, momentary negative affect). In addition to the effect evaluation, a process and economic evaluation will be conducted to investigate the credibility and generalizability of the intervention, and its cost-effectiveness. The potential effects of the ESM intervention may help caregivers to endure their care responsibilities and prevent them from becoming overburdened. This is the first ESM intervention for caregivers of people with dementia. The results of this study, therefore, provide a valuable contribution to the growing knowledge on m-health interventions for dementia caregivers. Dutch Trial Register NTR4847 ; date registered Oct 9, 2014.

Instructor feedback versus no instructor feedback on performance in a laparoscopic virtual reality simulator: a randomized educational trial

PubMed Central

2012-01-01

Abstract Background Several studies have found a positive effect on the learning curve as well as the improvement of basic psychomotor skills in the operating room after virtual reality training. Despite this, the majority of surgical and gynecological departments encounter hurdles when implementing this form of training. This is mainly due to lack of knowledge concerning the time and human resources needed to train novice surgeons to an adequate level. The purpose of this trial is to investigate the impact of instructor feedback regarding time, repetitions and self-perception when training complex operational tasks on a virtual reality simulator. Methods/Design The study population consists of medical students on their 4th to 6th year without prior laparoscopic experience. The study is conducted in a skills laboratory at a centralized university hospital. Based on a sample size estimation 98 participants will be randomized to an intervention group or a control group. Both groups have to achieve a predefined proficiency level when conducting a laparoscopic salpingectomy using a surgical virtual reality simulator. The intervention group receives standardized instructor feedback of 10 to 12 min a maximum of three times. The control group receives no instructor feedback. Both groups receive the automated feedback generated by the virtual reality simulator. The study follows the CONSORT Statement for randomized trials. Main outcome measures are time and repetitions to reach the predefined proficiency level on the simulator. We include focus on potential sex differences, computer gaming experience and self-perception. Discussion The findings will contribute to a better understanding of optimal training methods in surgical education. Trial Registration NCT01497782 PMID:22373062

Allelopathic potential of leaf and seed of Mucuna bracteata DC. ex Kurz on Eleusine indica (L.) gaertn

NASA Astrophysics Data System (ADS)

Halimshah, Syamimi; Ismail B., S.; Ahmad, Wan Juliana Wan

2015-09-01

A study was conducted to determine the allelopathic potential of leaf and seed of Mucuna bracteata on the growth of E. indica through aqueous extract and debris (incorporated into the soil) experiment. Three concentrations of leaf and seed aqueous extract (16.7, 33.3 and 66.7 g/L) and debris (2.5, 5.0 and 10.0 g/500 g soil) of M. bracteata were used in the experiment. Complete randomized design (CRD) with three replications was applied in this experiment which was conducted twice. Results demonstrated that the leaf and seed extracts of M. bracteata exhibited higher suppression effect on the growth and germination of E. indica as the concentration increased. The leaf and seed extracts significantly reduced all measured parameters at all concentrations except for the shoot length and germination of E. indica by seed extract at 16.7 g/L which recorded insignificant reduction by 40.5% and 4% respectively. The leaf and seed debris significantly reduced the root length of E. indica at all treatments. Seed debris also showed significant reduction on the germination at all treatments and other seedling growth parameters (shoot length, fresh weight and dry weight) at 2.5 and 10.0 g/500 g soil. Meanwhile, the leaf debris demonstrated stimulation effect on the seedling growth parameters. As a whole, the leaf showed higher suppression effect in aqueous extract experiment while the seed recorded higher suppression effect in the debris experiment. Further studies need to be conducted to investigate the type of inhibition mechanism involved in both experiments.

Modeling variability in porescale multiphase flow experiments

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

Ling, Bowen; Bao, Jie; Oostrom, Mart

Microfluidic devices and porescale numerical models are commonly used to study multiphase flow in biological, geological, and engineered porous materials. In this work, we perform a set of drainage and imbibition experiments in six identical microfluidic cells to study the reproducibility of multiphase flow experiments. We observe significant variations in the experimental results, which are smaller during the drainage stage and larger during the imbibition stage. We demonstrate that these variations are due to sub-porescale geometry differences in microcells (because of manufacturing defects) and variations in the boundary condition (i.e.,fluctuations in the injection rate inherent to syringe pumps). Computational simulationsmore » are conducted using commercial software STAR-CCM+, both with constant and randomly varying injection rate. Stochastic simulations are able to capture variability in the experiments associated with the varying pump injection rate.« less

Music-supported therapy in the rehabilitation of subacute stroke patients: a randomized controlled trial.

PubMed

Grau-Sánchez, Jennifer; Duarte, Esther; Ramos-Escobar, Neus; Sierpowska, Joanna; Rueda, Nohora; Redón, Susana; Veciana de Las Heras, Misericordia; Pedro, Jordi; Särkämö, Teppo; Rodríguez-Fornells, Antoni

2018-04-01

The effect of music-supported therapy (MST) as a tool to restore hemiparesis of the upper extremity after a stroke has not been appropriately contrasted with conventional therapy. The aim of this trial was to test the effectiveness of adding MST to a standard rehabilitation program in subacute stroke patients. A randomized controlled trial was conducted in which patients were randomized to MST or conventional therapy in addition to the rehabilitation program. The intensity and duration of the interventions were equated in both groups. Before and after 4 weeks of treatment, motor and cognitive functions, mood, and quality of life (QoL) of participants were evaluated. A follow-up at 3 months was conducted to examine the retention of motor gains. Both groups significantly improved their motor function, and no differences between groups were found. The only difference between groups was observed in the language domain for QoL. Importantly, an association was encountered between the capacity to experience pleasure from music activities and the motor improvement in the MST group. MST as an add-on treatment showed no superiority to conventional therapies for motor recovery. Importantly, patient's intrinsic motivation to engage in musical activities was associated with better motor improvement. © 2018 New York Academy of Sciences.

Selecting the best design for nonstandard toxicology experiments.

PubMed

Webb, Jennifer M; Smucker, Byran J; Bailer, A John

2014-10-01

Although many experiments in environmental toxicology use standard statistical experimental designs, there are situations that arise where no such standard design is natural or applicable because of logistical constraints. For example, the layout of a laboratory may suggest that each shelf serve as a block, with the number of experimental units per shelf either greater than or less than the number of treatments in a way that precludes the use of a typical block design. In such cases, an effective and powerful alternative is to employ optimal experimental design principles, a strategy that produces designs with precise statistical estimates. Here, a D-optimal design was generated for an experiment in environmental toxicology that has 2 factors, 16 treatments, and constraints similar to those described above. After initial consideration of a randomized complete block design and an intuitive cyclic design, it was decided to compare a D-optimal design and a slightly more complicated version of the cyclic design. Simulations were conducted generating random responses under a variety of scenarios that reflect conditions motivated by a similar toxicology study, and the designs were evaluated via D-efficiency as well as by a power analysis. The cyclic design performed well compared to the D-optimal design. © 2014 SETAC.

Unsupervised Metric Fusion Over Multiview Data by Graph Random Walk-Based Cross-View Diffusion.

PubMed

Wang, Yang; Zhang, Wenjie; Wu, Lin; Lin, Xuemin; Zhao, Xiang

2017-01-01

Learning an ideal metric is crucial to many tasks in computer vision. Diverse feature representations may combat this problem from different aspects; as visual data objects described by multiple features can be decomposed into multiple views, thus often provide complementary information. In this paper, we propose a cross-view fusion algorithm that leads to a similarity metric for multiview data by systematically fusing multiple similarity measures. Unlike existing paradigms, we focus on learning distance measure by exploiting a graph structure of data samples, where an input similarity matrix can be improved through a propagation of graph random walk. In particular, we construct multiple graphs with each one corresponding to an individual view, and a cross-view fusion approach based on graph random walk is presented to derive an optimal distance measure by fusing multiple metrics. Our method is scalable to a large amount of data by enforcing sparsity through an anchor graph representation. To adaptively control the effects of different views, we dynamically learn view-specific coefficients, which are leveraged into graph random walk to balance multiviews. However, such a strategy may lead to an over-smooth similarity metric where affinities between dissimilar samples may be enlarged by excessively conducting cross-view fusion. Thus, we figure out a heuristic approach to controlling the iteration number in the fusion process in order to avoid over smoothness. Extensive experiments conducted on real-world data sets validate the effectiveness and efficiency of our approach.

Cell cultivation under different gravitational loads using a novel random positioning incubator

PubMed Central

Benavides Damm, Tatiana; Walther, Isabelle; Wüest, Simon L; Sekler, Jörg; Egli, Marcel

2014-01-01

Important in biotechnology is the establishment of cell culture methods that reflect the in vivo situation accurately. One approach for reaching this goal is through 3D cell cultivation that mimics tissue or organ structures and functions. We present here a newly designed and constructed random positioning incubator (RPI) that enables 3D cell culture in simulated microgravity (0 g). In addition to growing cells in a weightlessness-like environment, our RPI enables long-duration cell cultivation under various gravitational loads, ranging from close to 0 g to almost 1 g. This allows the study of the mechanotransductional process of cells involved in the conversion of physical forces to an appropriate biochemical response. Gravity is a type of physical force with profound developmental implications in cellular systems as it modulates the resulting signaling cascades as a consequence of mechanical loading. The experiments presented here were conducted on mouse skeletal myoblasts and human lymphocytes, two types of cells that have been shown in the past to be particularly sensitive to changes in gravity. Our novel RPI will expand the horizon at which mechanobiological experiments are conducted. The scientific data gathered may not only improve the sustainment of human life in space, but also lead to the design of alternative countermeasures against diseases related to impaired mechanosensation and downstream signaling processes on earth. PMID:24375199

A Randomized, Controlled Trial of Emotional Disclosure in Rheumatoid Arthritis: Can Clinician Assistance Enhance the Effects?

PubMed Central

Keefe, Francis J.; Anderson, Timothy; Lumley, Mark; Caldwell, David; Stainbrook, David; Mckee, Daphne; Waters, Sandra J.; Connelly, Mark; Affleck, Glenn; Pope, Mary Susan; Weiss, Marianne; Riordan, Paul A.; Uhlin, Brian D.

2008-01-01

Emotional disclosure by writing or talking about stressful life experiences improves health status in non-clinical populations, but its success in clinical populations, particularly rheumatoid arthritis (RA), has been mixed. In this randomized, controlled trial, we attempted to increase the efficacy of emotional disclosure by having a trained clinician help patients emotionally disclose and process stressful experiences. We randomized 98 adults with RA to one of four conditions: a) private verbal emotional disclosure; b) clinician-assisted verbal emotional disclosure; c) arthritis information control (all of which engaged in four, 30-minute laboratory sessions); or d) no-treatment, standard care only control group. Outcome measures (pain, disability, affect, stress) were assessed at baseline, 2 months following treatment (2-month follow-up), and at 5-month, and 15-month follow-ups. A manipulation check demonstrated that, as expected, both types of emotional disclosure led to immediate (post-session) increases in negative affect compared with arthritis information. Outcome analyses at all three follow-ups revealed no clear pattern of effects for either clinician-assisted or private emotional disclosure compared with the two control groups. There were some benefits in terms of a reduction in pain behavior with private disclosure versus clinician-assisted disclosure at the 2 month follow-up, but no other significant between group differences. We conclude that verbal emotional disclosure about stressful experiences, whether conducted privately or assisted by a clinician, has little or no benefit for people with RA. PMID:17923329

Safer disclosure of HIV serostatus for women living with HIV who experience or fear violence: a systematic review.

PubMed

Kennedy, Caitlin E; Haberlen, Sabina; Amin, Avni; Baggaley, Rachel; Narasimhan, Manjulaa

2015-01-01

Supporting individuals as they disclose their HIV serostatus may lead to a variety of individual and public health benefits. However, many women living with HIV are hesitant to disclose their HIV status due to fear of negative outcomes such as violence, abandonment, relationship dissolution and stigma. We conducted a systematic review of studies evaluating interventions to facilitate safer disclosure of HIV status for women living with HIV who experience or fear violence. Articles, conference abstracts and programme reports were included if they reported post-intervention evaluation results and were published before 1 April 2015. Searching was conducted through electronic databases for peer-reviewed articles and conference abstracts, reviewing websites of relevant organizations for grey literature, hand searching reference lists of included studies and contacting experts. Systematic methods were used for screening and data abstraction, which was conducted in duplicate. Study quality (rigor) was assessed with the Cochrane risk of bias tool. Two interventions met the inclusion criteria: the Safe Homes and Respect for Everyone cluster-randomized trial of combination HIV and intimate partner violence (IPV) services in Rakai, Uganda, and the South Africa HIV/AIDS Antenatal Post-Test Support study individual randomized trial of an enhanced counselling intervention for pregnant women undergoing HIV testing and counselling. Both programmes integrated screening for IPV into HIV testing services and trained counsellors to facilitate discussions about disclosure based on a woman's risk of violence. However, both were implemented as part of multiple-component interventions, making it impossible to isolate the impact of the safer disclosure components. The existing evidence base for interventions to facilitate safe HIV serostatus disclosure for women who experience or fear violence is limited. Development and implementation of new approaches and rigorous evaluation of safe disclosure outcomes is needed to guide programme planners and policy makers.

Sample Selection in Randomized Experiments: A New Method Using Propensity Score Stratified Sampling

ERIC Educational Resources Information Center

Tipton, Elizabeth; Hedges, Larry; Vaden-Kiernan, Michael; Borman, Geoffrey; Sullivan, Kate; Caverly, Sarah

2014-01-01

Randomized experiments are often seen as the "gold standard" for causal research. Despite the fact that experiments use random assignment to treatment conditions, units are seldom selected into the experiment using probability sampling. Very little research on experimental design has focused on how to make generalizations to well-defined…

Searching for Survivors through Random Human-Body Movement Outdoors by Continuous-Wave Radar Array

PubMed Central

Liu, Miao; Li, Zhao; Liang, Fulai; Jing, Xijing; Lu, Guohua; Wang, Jianqi

2016-01-01

It is a major challenge to search for survivors after chemical or nuclear leakage or explosions. At present, biological radar can be used to achieve this goal by detecting the survivor’s respiration signal. However, owing to the random posture of an injured person at a rescue site, the radar wave may directly irradiate the person’s head or feet, in which it is difficult to detect the respiration signal. This paper describes a multichannel-based antenna array technology, which forms an omnidirectional detection system via 24-GHz Doppler biological radar, to address the random positioning relative to the antenna of an object to be detected. Furthermore, since the survivors often have random body movement such as struggling and twitching, the slight movements of the body caused by breathing are obscured by these movements. Therefore, a method is proposed to identify random human-body movement by utilizing multichannel information to calculate the background variance of the environment in combination with a constant-false-alarm-rate detector. The conducted outdoor experiments indicate that the system can realize the omnidirectional detection of random human-body movement and distinguish body movement from environmental interference such as movement of leaves and grass. The methods proposed in this paper will be a promising way to search for survivors outdoors. PMID:27073860

Searching for Survivors through Random Human-Body Movement Outdoors by Continuous-Wave Radar Array.

PubMed

Li, Chuantao; Chen, Fuming; Qi, Fugui; Liu, Miao; Li, Zhao; Liang, Fulai; Jing, Xijing; Lu, Guohua; Wang, Jianqi

2016-01-01

It is a major challenge to search for survivors after chemical or nuclear leakage or explosions. At present, biological radar can be used to achieve this goal by detecting the survivor's respiration signal. However, owing to the random posture of an injured person at a rescue site, the radar wave may directly irradiate the person's head or feet, in which it is difficult to detect the respiration signal. This paper describes a multichannel-based antenna array technology, which forms an omnidirectional detection system via 24-GHz Doppler biological radar, to address the random positioning relative to the antenna of an object to be detected. Furthermore, since the survivors often have random body movement such as struggling and twitching, the slight movements of the body caused by breathing are obscured by these movements. Therefore, a method is proposed to identify random human-body movement by utilizing multichannel information to calculate the background variance of the environment in combination with a constant-false-alarm-rate detector. The conducted outdoor experiments indicate that the system can realize the omnidirectional detection of random human-body movement and distinguish body movement from environmental interference such as movement of leaves and grass. The methods proposed in this paper will be a promising way to search for survivors outdoors.

Efficacy of abstinence promotion media messages: findings from an online randomized trial.

PubMed

Evans, W Douglas; Davis, Kevin C; Ashley, Olivia Silber; Blitstein, Jonathan; Koo, Helen; Zhang, Yun

2009-10-01

We conducted an online randomized experiment to evaluate the efficacy of messages from the Parents Speak Up National Campaign (PSUNC) to promote parent-child communication about sex. We randomly assigned a national sample of 1,969 mothers and fathers to treatment (PSUNC exposure) and control (no exposure) conditions. Mothers were further randomized into treatment and booster (additional messages) conditions to evaluate dose-response effects. Participants were surveyed at baseline, 4 weeks postexposure, and 6 months postexposure. We used multivariable logistic regression procedures in our analysis. Treatment fathers were more likely than control fathers to initiate conversations about sex at 4 weeks, and treatment fathers and mothers were more likely than controls at 6 months to recommend that their children wait to have sex. Treatment fathers and mothers were far more likely than controls to use the campaign Web site. There was a dose-response effect for mothers' Web site use. Using new media methods, this study shows that PSUNC messages are efficacious in promoting parent-child communication about sex and abstinence. Future research should evaluate mechanisms and effectiveness in natural settings.

Mental skills training with basic combat training soldiers: A group-randomized trial.

PubMed

Adler, Amy B; Bliese, Paul D; Pickering, Michael A; Hammermeister, Jon; Williams, Jason; Harada, Coreen; Csoka, Louis; Holliday, Bernie; Ohlson, Carl

2015-11-01

Cognitive skills training has been linked to greater skills, self-efficacy, and performance. Although research in a variety of organizational settings has demonstrated training efficacy, few studies have assessed cognitive skills training using rigorous, longitudinal, randomized trials with active controls. The present study examined cognitive skills training in a high-risk occupation by randomizing 48 platoons (N = 2,432 soldiers) in basic combat training to either (a) mental skills training or (b) an active comparison condition (military history). Surveys were conducted at baseline and 3 times across the 10-week course. Multilevel mixed-effects models revealed that soldiers in the mental skills training condition reported greater use of a range of cognitive skills and increased confidence relative to those in the control condition. Soldiers in the mental skills training condition also performed better on obstacle course events, rappelling, physical fitness, and initial weapons qualification scores, although effects were generally moderated by gender and previous experience. Overall, effects were small; however, given the rigor of the design, the findings clearly contribute to the broader literature by providing supporting evidence that cognitive training skills can enhance performance in occupational and sports settings. Future research should address gender and experience to determine the need for targeting such training appropriately. (c) 2015 APA, all rights reserved).

A Randomized Controlled Trial of Clinician-Supported Problem-Solving Bibliotherapy for Family Caregivers of People With First-Episode Psychosis.

PubMed

Chien, Wai Tong; Thompson, David R; Lubman, Dan I; McCann, Terence V

2016-11-01

Family interventions for first-episode psychosis (FEP) are an integral component of treatment, with positive effects mainly on patients' mental state and relapse rate. However, comparatively little attention has been paid to the effects of family interventions on caregivers' stress coping and well-being, especially in non-Western countries. We aimed to test the effects of a 5-month clinician-supported problem-solving bibliotherapy (CSPSB) for Chinese family caregivers of people with FEP in improving family burden and carers' problem-solving and caregiving experience, and in reducing psychotic symptoms and duration of re-hospitalizations, compared with those only received usual outpatient family support (UOFS). A randomized controlled trial was conducted across 2 early psychosis clinics in Hong Kong, where there might be inadequate usual family support services for FEP patients. A total of 116 caregivers were randomly selected, and after baseline measurement, randomly assigned to the CSPSB or UOFS. They were also assessed at 1-week and 6- and 12-month post-intervention. Intention-to-treat analyses were applied and indicated that the CSPSB group reported significantly greater improvements in family burden and caregiving experience, and reductions in severity of psychotic symptoms and duration of re-hospitalizations, than the UOFS group at 6- and 12-month follow-up. CSPSB produces moderate long-term benefits to caregivers and FEP patients, and is a low-cost adjunct to UOFS. © The Author 2016. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center.

Do health care institutions value research? A mixed methods study of barriers and facilitators to methodological rigor in pediatric randomized trials.

PubMed

Hamm, Michele P; Scott, Shannon D; Klassen, Terry P; Moher, David; Hartling, Lisa

2012-10-18

Pediatric randomized controlled trials (RCTs) are susceptible to a high risk of bias. We examined the barriers and facilitators that pediatric trialists face in the design and conduct of unbiased trials. We used a mixed methods design, with semi-structured interviews building upon the results of a quantitative survey. We surveyed Canadian (n=253) and international (n=600) pediatric trialists regarding their knowledge and awareness of bias and their perceived barriers and facilitators in conducting clinical trials. We then interviewed 13 participants from different subspecialties and geographic locations to gain a more detailed description of how their experiences and attitudes towards research interacted with trial design and conduct. The survey response rate was 23.0% (186/807). 68.1% of respondents agreed that bias is a problem in pediatric RCTs and 72.0% felt that there is sufficient evidence to support changing some aspects of how trials are conducted. Knowledge related to bias was variable, with inconsistent awareness of study design features that may introduce bias into a study. Interview participants highlighted a lack of formal training in research methods, a negative research culture, and the pragmatics of trial conduct as barriers. Facilitators included contact with knowledgeable and supportive colleagues and infrastructure for research. A lack of awareness of bias and negative attitudes towards research present significant barriers in terms of conducting methodologically rigorous pediatric RCTs. Knowledge translation efforts must focus on these issues to ensure the relevance and validity of trial results.

Scanning gate microscopy of quantum rings: effects of an external magnetic field and of charged defects.

PubMed

Pala, M G; Baltazar, S; Martins, F; Hackens, B; Sellier, H; Ouisse, T; Bayot, V; Huant, S

2009-07-01

We study scanning gate microscopy (SGM) in open quantum rings obtained from buried semiconductor InGaAs/InAlAs heterostructures. By performing a theoretical analysis based on the Keldysh-Green function approach we interpret the radial fringes observed in experiments as the effect of randomly distributed charged defects. We associate SGM conductance images with the local density of states (LDOS) of the system. We show that such an association cannot be made with the current density distribution. By varying an external magnetic field we are able to reproduce recursive quasi-classical orbits in LDOS and conductance images, which bear the same periodicity as the Aharonov-Bohm effect.

Cranberry Reduces the Risk of Urinary Tract Infection Recurrence in Otherwise Healthy Women: A Systematic Review and Meta-Analysis.

PubMed

Fu, Zhuxuan; Liska, DeAnn; Talan, David; Chung, Mei

2017-12-01

Background: Cranberry ( Vaccinium spp.) has been advocated for treatment of urinary tract infection (UTI); however, its efficacy is controversial. Women have a 50% risk of UTI over their lifetime, and ∼20-30% experience a subsequent UTI recurrence. Objective: We conducted this meta-analysis to assess the effect of cranberry on the risk of UTI recurrence in otherwise healthy women. Methods: Literature published before January 2011 was obtained from 2 published systematic reviews, and we conducted updated searches in EMBASE and MEDLINE (through July 2017). We included randomized controlled trials that were conducted in generally healthy nonpregnant women aged ≥18 y with a history of UTI, compared cranberry intervention to a placebo or control, and reported the outcome as the number of participants experiencing a UTI. Two researchers conducted abstract and full-text screenings, data extractions, and risk of bias assessments independently, and discrepancies were resolved by group consensus. Meta-analyses were performed by using Stata SE software (version 13). We employed a fixed-effect model using the Mantel-Haenszel method to estimate the summary risk if the heterogeneity was low to moderate ( I 2 < 50%). Otherwise, we applied a random-effects model using the DerSimonian-Laird method. Results: We identified 7 randomized controlled trials conducted in healthy women at risk of UTI ( n = 1498 participants). Results of the meta-analysis showed that cranberry reduced the risk of UTI by 26% (pooled risk ratio: 0.74; 95% CI: 0.55, 0.98; I 2 = 54%). Risk of bias indicated that 2 studies had high loss to follow-up or selective outcome reporting. Overall, the studies were relatively small, with only 2 having >300 participants. Conclusion: These results suggest that cranberry may be effective in preventing UTI recurrence in generally healthy women; however, larger high-quality studies are needed to confirm these findings. This trial was registered at crd.york.ac.uk/prospero as CRD42015024439. © 2017 American Society for Nutrition.

Anger, frustration, boredom and the Department of Motor Vehicles: Can negative emotions impede organ donor registration?

PubMed

Siegel, Jason T; Tan, Cara N; Rosenberg, Benjamin D; Navarro, Mario A; Thomson, Andrew L; Lyrintzis, Elena A; Alvaro, Eusebio M; Jones, Natalie D

2016-03-01

The IIFF Model (Information, Immediate and Complete Registration Mechanism, Focused Engagement, Favorable Activation) offers a checklist of considerations for interventions seeking to influence organ donor registration behavior. One aspect of the model, favorable activation, recommends considering the emotional and motivational state of a potential donor registrant. Given that most donor registrations occur at the Department of Motor Vehicles (DMV), we considered whether emotions experienced while at the DMV could influence registration rates. The current research effort investigated the emotions people experience while visiting the DMV, explored whether these emotions are associated with donor registration intentions, and experimentally assessed whether DMV experiences influence donor registration. Three studies were conducted through Amazon's Mechanical Turk. In Study 1, we randomly assigned participants to either recall a prior DMV experience or to a comparison condition. Emotions associated with the recalled experiences were the dependent variable. Study 2 assessed the correlations between nine different emotions and donor registration intentions. Study 3 randomly assigned participants to recall a prior frustrating DMV experience or to a comparison condition. Intention to register to donate was the dependent variable. Study 1 found that recalling a prior DMV experience was associated with more negative and less positive emotions than the comparison condition. Study 2 found that increased levels of negative emotion could be problematic, as negative emotions were associated with decreased donor intentions. Study 3 found that recalling a frustrating DMV experience resulted in significantly lower intentions to register as an organ donor (vs. a control condition). Although not all DMV experiences are negative, these data indicated a relationship between the DMV and negative emotions; an association between negative emotions and lower donor registration intentions; and, a causal relationship between negative DMV experiences and decreased registration intentions. Copyright © 2016 Elsevier Ltd. All rights reserved.

A comparison of two differential methods for nutrition education in elementary school: lecture-and experience-based learning program.

PubMed

Jung, Lan-Hee; Choi, Jeong-Hwa; Bang, Hyun-Mi; Shin, Jun-Ho; Heo, Young-Ran

2015-02-01

This research was conducted to compare lecture-and experience-based methods of nutritional education as well as provide fundamental data for developing an effective nutritional education program in elementary schools. A total of 110 students in three elementary schools in Jeollanam-do were recruited and randomly distributed in lecture-and experience-based groups. The effects of education on students' dietary knowledge, dietary behaviors, and dietary habits were analyzed using a pre/post-test. Lecture-and experience-based methods did not significantly alter total scores for dietary knowledge in any group, although lecture-based method led to improvement for some detailed questions. In the experience-based group, subjects showed significant alteration of dietary behaviors, whereas lecture-based method showed alteration of dietary habits. These outcomes suggest that lecture-and experience-based methods led to differential improvement of students' dietary habits, behaviors, and knowledge. To obtain better nutritional education results, both lectures and experiential activities need to be considered.

Reduced thermal conductivity of nanotwinned random layer structures: a promising nanostructuring towards efficient Si and Si/Ge thermoelectric materials

NASA Astrophysics Data System (ADS)

Samaraweera, Nalaka; Chan, Kin L.; Mithraratne, Kumar

2018-05-01

Si and Si/Ge based nanostructures of reduced lattice thermal conductivity are widely attractive for developing efficient thermoelectric materials. In this study, we demonstrate the reduced thermal conductivity of Si nanotwinned random layer (NTRL) structures over corresponding superlattice and twin-free counterparts. The participation ratio analysis of vibrational modes shows that a possible cause of thermal conductivity reduction is phonon localization due to the random arrangement of twin boundaries. Via non-equilibrium molecular dynamic simulations, it is shown that ~23 and ~27% reductions over superlattice counterparts and ~55 and 53% over twin-free counterparts can be attained for the structures of total lengths of 90 and 170 nm, respectively. Furthermore, a random twin boundary distribution is applied for Si/Ge random layer structures seeking further reduction of thermal conductivity. A significant reduction in thermal conductivity of Si/Ge structures exceeding the thermal insulating performance of the corresponding amorphous Si structure by ~31% for a total length of 90 nm can be achieved. This reduction is as high as ~98% compared to the twin-free Si counterpart. It is demonstrated that application of randomly organised nanoscale twin boundaries is a promising nanostructuring strategy towards developing efficient Si and Si/Ge based thermoelectric materials in the future.

Anomalous transport in fracture networks: field scale experiments and modelling

NASA Astrophysics Data System (ADS)

Kang, P. K.; Le Borgne, T.; Bour, O.; Dentz, M.; Juanes, R.

2012-12-01

Anomalous transport is widely observed in different settings and scales of transport through porous and fractured geologic media. A common signature of anomalous transport is the late-time power law tailing in breakthrough curves (BTCs) during tracer tests. Various conceptual models of anomalous transport have been proposed, including multirate mass transfer, continuous time random walk, and stream tube models. Since different conceptual models can produce equally good fits to a single BTC, tracer test interpretation has been plagued with ambiguity. Here, we propose to resolve such ambiguity by analyzing BTCs obtained from both convergent and push-pull flow configurations at two different fracture planes. We conducted field tracer tests in a fractured granite formation close to Ploemeur, France. We observe that BTC tailing depends on the flow configuration and the injection fracture. Specifically the tailing disappears under push-pull geometry, and when we injected at a fracture with high flux (Figure 1). This indicates that for this fractured granite, BTC tailing is controlled by heterogeneous advection and not by matrix diffusion. To explain the change in tailing behavior for different flow configurations, we employ a simple lattice network model with heterogeneous conductivity distribution. The model assigns random conductivities to the fractures and solves the Darcy equation for an incompressible fluid, enforcing mass conservation at fracture intersections. The mass conservation constraint yields a correlated random flow through the fracture system. We investigate whether BTC tailing can be explained by the spatial distribution of preferential flow paths and stagnation zones, which is controlled by the conductivity variance and correlation length. By combining the results from the field tests and numerical modeling, we show that the reversibility of spreading is a key mechanism that needs to be captured. We also demonstrate the dominant role of the injection fracture on the tailing behavior: where we inject makes the difference in the tailing. Blue line is a BTC with injection into a slow velocity zone under convergent flow configuration. The late-time tailing observed for the convergent test diminished for push-pull experiment performed in the same zone(red line). Black line is a BTC with injection into a high velocity zone under convergent flow configuration. Insets: illustration of convergent and push-pull tracer tests using a double packer system.

Individual Differences Methods for Randomized Experiments

ERIC Educational Resources Information Center

Tucker-Drob, Elliot M.

2011-01-01

Experiments allow researchers to randomly vary the key manipulation, the instruments of measurement, and the sequences of the measurements and manipulations across participants. To date, however, the advantages of randomized experiments to manipulate both the aspects of interest and the aspects that threaten internal validity have been primarily…

Challenges and Innovations in a Community-Based Participatory Randomized Controlled Trial.

PubMed

Goodkind, Jessica R; Amer, Suha; Christian, Charlisa; Hess, Julia Meredith; Bybee, Deborah; Isakson, Brian L; Baca, Brandon; Ndayisenga, Martin; Greene, R Neil; Shantzek, Cece

2017-02-01

Randomized controlled trials (RCTs) are a long-standing and important design for conducting rigorous tests of the effectiveness of health interventions. However, many questions have been raised about the external validity of RCTs, their utility in explicating mechanisms of intervention and participants' intervention experiences, and their feasibility and acceptability. In the current mixed-methods study, academic and community partners developed and implemented an RCT to test the effectiveness of a collaboratively developed community-based advocacy, learning, and social support intervention. The goals of the intervention were to address social determinants of health and build trust and connections with other mental health services in order to reduce mental health disparities among Afghan, Great Lakes Region African, and Iraqi refugee adults and to engage and retain refugees in trauma-focused treatment, if needed. Two cohorts completed the intervention between 2013 and 2015. Ninety-three adult refugees were randomly assigned to intervention or control group and completed four research interviews (pre-, mid-, and postintervention, and follow-up). Several challenges to conducting a community-based RCT emerged, including issues related to interviewer intervention to assist participants in the control group, diffusion of intervention resources throughout the small refugee communities, and staff and community concerns about the RCT design and what evidence is meaningful to demonstrate intervention effectiveness. These findings highlight important epistemological, methodological, and ethical challenges that should be considered when conducting community-based RCTs and interpreting results from them. In addition, several innovations were developed to address these challenges, which may be useful for other community-academic partnerships engaged in RCTs.

CHALLENGES AND INNOVATIONS IN A COMMUNITY-BASED PARTICIPATORY RANDOMIZED CONTROLLED TRIAL

PubMed Central

Goodkind, Jessica R.; Amer, Suha; Christian, Charlisa; Hess, Julia Meredith; Bybee, Deborah; Isakson, Brian; Baca, Brandon; Ndaysenga, Martin; Greene, R. Neil; Shantzek, Cece

2016-01-01

Randomized controlled trials (RCTs) are a long-standing and important design for conducting rigorous tests of the effectiveness of health interventions. However, many questions have been raised about the external validity of RCTs, their utility in explicating mechanisms of intervention and participants’ intervention experiences, and their feasibility and acceptability. In the current mixed methods study, academic and community partners developed and implemented an RCT to test the effectiveness of a collaboratively developed community-based advocacy, learning, and social support intervention. The goals of the intervention were to address social determinants of health and build trust and connections with other mental health services in order to reduce mental health disparities among Afghan, Great Lakes Region African and Iraqi refugee adults and engage and retain refugees in trauma-focused treatment, if needed. Two cohorts completed the intervention between 2013-2015. Ninety-three adult refugees were randomly assigned to intervention or control group and completed four research interviews (pre-, mid-, post-intervention, and follow-up). Several challenges to conducting a community-based RCT emerged, including issues related to interviewer intervention to assist participants in the control group, diffusion of intervention resources throughout the small refugee communities, and staff and community concerns about the RCT design and what evidence is meaningful to demonstrate intervention effectiveness. These findings highlight important epistemological, methodological, and ethical challenges that should be considered when conducting community-based RCTs and interpreting results from them. In addition, several innovations were developed to address these challenges, which may be useful for other community-academic partnerships engaged in RCTs. PMID:27179291

Maintaining Engagement in Long-term Interventions with Relational Agents

PubMed Central

Bickmore, Timothy; Schulman, Daniel; Yin, Langxuan

2011-01-01

We discuss issues in designing virtual humans for applications which require long-term voluntary use, and the problem of maintaining engagement with users over time. Concepts and theories related to engagement from a variety of disciplines are reviewed. We describe a platform for conducting studies into long-term interactions between humans and virtual agents, and present the results of two longitudinal randomized controlled experiments in which the effect of manipulations of agent behavior on user engagement was assessed. PMID:21318052

A Data Management System Integrating Web-based Training and Randomized Trials: Requirements, Experiences and Recommendations.

PubMed

Muroff, Jordana; Amodeo, Maryann; Larson, Mary Jo; Carey, Margaret; Loftin, Ralph D

2011-01-01

This article describes a data management system (DMS) developed to support a large-scale randomized study of an innovative web-course that was designed to improve substance abuse counselors' knowledge and skills in applying a substance abuse treatment method (i.e., cognitive behavioral therapy; CBT). The randomized trial compared the performance of web-course-trained participants (intervention group) and printed-manual-trained participants (comparison group) to determine the effectiveness of the web-course in teaching CBT skills. A single DMS was needed to support all aspects of the study: web-course delivery and management, as well as randomized trial management. The authors briefly reviewed several other systems that were described as built either to handle randomized trials or to deliver and evaluate web-based training. However it was clear that these systems fell short of meeting our needs for simultaneous, coordinated management of the web-course and the randomized trial. New England Research Institute's (NERI) proprietary Advanced Data Entry and Protocol Tracking (ADEPT) system was coupled with the web-programmed course and customized for our purposes. This article highlights the requirements for a DMS that operates at the intersection of web-based course management systems and randomized clinical trial systems, and the extent to which the coupled, customized ADEPT satisfied those requirements. Recommendations are included for institutions and individuals considering conducting randomized trials and web-based training programs, and seeking a DMS that can meet similar requirements.

Random gauge models of the superconductor-insulator transition in two-dimensional disordered superconductors

NASA Astrophysics Data System (ADS)

Granato, Enzo

2017-11-01

We study numerically the superconductor-insulator transition in two-dimensional inhomogeneous superconductors with gauge disorder, described by four different quantum rotor models: a gauge glass, a flux glass, a binary phase glass, and a Gaussian phase glass. The first two models describe the combined effect of geometrical disorder in the array of local superconducting islands and a uniform external magnetic field, while the last two describe the effects of random negative Josephson-junction couplings or π junctions. Monte Carlo simulations in the path-integral representation of the models are used to determine the critical exponents and the universal conductivity at the quantum phase transition. The gauge- and flux-glass models display the same critical behavior, within the estimated numerical uncertainties. Similar agreement is found for the binary and Gaussian phase-glass models. Despite the different symmetries and disorder correlations, we find that the universal conductivity of these models is approximately the same. In particular, the ratio of this value to that of the pure model agrees with recent experiments on nanohole thin-film superconductors in a magnetic field, in the large disorder limit.

The behaviour and welfare of sows and piglets in farrowing crates or lactation pens.

PubMed

Singh, C; Verdon, M; Cronin, G M; Hemsworth, P H

2017-07-01

Temporary confinement during parturition and early postpartum may provide an intermediary step preceding loose housing that offers improvement in sow and piglet welfare. Three experiments were conducted to investigate the implications of replacing farrowing crates (FCs) with an alternative housing system from 3 days postpartum until weaning. In each experiment sows farrowed in FCs and were randomly allocated at day 3 of lactation to either a FC or a pen with increased floor space (lactation pen (LP)) until weaning. In experiment 1, piglet growth and sow and piglet skin injuries were recorded for 32 sows and 128 focal piglets in these litters. Behaviour around nursing and piglet behavioural time budgets were also recorded for 24 of these litters (96 focal piglets for time budgets). In experiment 2, measures of skin injury and behavioural time budgets were conducted on 28 sows and 112 focal piglets. The behavioural response of sows to piglet vocalisation (maternal responsiveness test (MRT)) was also assessed. In experiment 3, piglet mortality from day 3 of lactation until weaning was recorded in 672 litters over 12 months. While housing did not affect piglet weight gain in experiment 1, or piglet skin injuries in experiments 1 or 2, sows in both experiments sustained more injuries in LP than FC (experiment 1, 2.9 v. 1.4; experiment 2, 2.5 v. 0.8 lesions/sow; P0.05). Thus, housing sows and litters in LP from day 3 of lactation minimises piglet mortality while improving maternal behaviour in sows and social behaviour in piglets.

Implementation of nitrogen-doped titanium-tungsten tunable heater in phase change random access memory and its effects on device performance

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

Tan, Chun Chia; Zhao, Rong, E-mail: zhao-rong@sutd.edu.sg; Chong, Tow Chong

2014-10-13

Nitrogen-doped titanium-tungsten (N-TiW) was proposed as a tunable heater in Phase Change Random Access Memory (PCRAM). By tuning N-TiW's material properties through doping, the heater can be tailored to optimize the access speed and programming current of PCRAM. Experiments reveal that N-TiW's resistivity increases and thermal conductivity decreases with increasing nitrogen-doping ratio, and N-TiW devices displayed (∼33% to ∼55%) reduced programming currents. However, there is a tradeoff between the current and speed for heater-based PCRAM. Analysis of devices with different N-TiW heaters shows that N-TiW doping levels could be optimized to enable low RESET currents and fast access speeds.

Kalman filter data assimilation: targeting observations and parameter estimation.

PubMed

Bellsky, Thomas; Kostelich, Eric J; Mahalov, Alex

2014-06-01

This paper studies the effect of targeted observations on state and parameter estimates determined with Kalman filter data assimilation (DA) techniques. We first provide an analytical result demonstrating that targeting observations within the Kalman filter for a linear model can significantly reduce state estimation error as opposed to fixed or randomly located observations. We next conduct observing system simulation experiments for a chaotic model of meteorological interest, where we demonstrate that the local ensemble transform Kalman filter (LETKF) with targeted observations based on largest ensemble variance is skillful in providing more accurate state estimates than the LETKF with randomly located observations. Additionally, we find that a hybrid ensemble Kalman filter parameter estimation method accurately updates model parameters within the targeted observation context to further improve state estimation.

Kalman filter data assimilation: Targeting observations and parameter estimation

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

Bellsky, Thomas, E-mail: bellskyt@asu.edu; Kostelich, Eric J.; Mahalov, Alex

2014-06-15

This paper studies the effect of targeted observations on state and parameter estimates determined with Kalman filter data assimilation (DA) techniques. We first provide an analytical result demonstrating that targeting observations within the Kalman filter for a linear model can significantly reduce state estimation error as opposed to fixed or randomly located observations. We next conduct observing system simulation experiments for a chaotic model of meteorological interest, where we demonstrate that the local ensemble transform Kalman filter (LETKF) with targeted observations based on largest ensemble variance is skillful in providing more accurate state estimates than the LETKF with randomly locatedmore » observations. Additionally, we find that a hybrid ensemble Kalman filter parameter estimation method accurately updates model parameters within the targeted observation context to further improve state estimation.« less

A short history of randomized experiments in criminology. A meager feast.

PubMed

Farrington, David P

2003-06-01

This article discusses advantages of randomized experiments and key issues raised in the following articles. The main concern is the growth and decrease in the use of randomized experiments by the California Youth Authority, the U.S. National Institute of Justice, and the British Home Office, although other experiments are also discussed. It is concluded that feast and famine periods are influenced by key individuals. It is recommended that policy makers, practitioners, funders, the mass media, and the general public need better education in research quality so that they can tell the difference between good and poor evaluation studies. They might then demand better evaluations using randomized experiments.

Causal inference from observational data.

PubMed

Listl, Stefan; Jürges, Hendrik; Watt, Richard G

2016-10-01

Randomized controlled trials have long been considered the 'gold standard' for causal inference in clinical research. In the absence of randomized experiments, identification of reliable intervention points to improve oral health is often perceived as a challenge. But other fields of science, such as social science, have always been challenged by ethical constraints to conducting randomized controlled trials. Methods have been established to make causal inference using observational data, and these methods are becoming increasingly relevant in clinical medicine, health policy and public health research. This study provides an overview of state-of-the-art methods specifically designed for causal inference in observational data, including difference-in-differences (DiD) analyses, instrumental variables (IV), regression discontinuity designs (RDD) and fixed-effects panel data analysis. The described methods may be particularly useful in dental research, not least because of the increasing availability of routinely collected administrative data and electronic health records ('big data'). © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Recruiting Filipino Immigrants in a Randomized Controlled Trial Promoting Enrollment in an Evidence-Based Parenting Intervention.

PubMed

Javier, Joyce R; Reyes, Angela; Coffey, Dean M; Schrager, Sheree M; Samson, Allan; Palinkas, Lawrence; Kipke, Michele D; Miranda, Jeanne

2018-05-17

Filipinos, the second largest Asian subgroup in the U.S., experience significant youth behavioral health disparities but remain under-represented in health research. We describe lessons learned from using the Matching Model of Recruitment to recruit 215 Filipinos to participate in a large, randomized controlled trial of a culturally tailored video aimed at increasing enrollment in the Incredible Years® Parent Program. We recruited participants from schools, churches, clinics, community events, and other community-based locations. Facilitators of participation included: partnership with local community groups, conducting research in familiar settings, building on existing social networks, and matching perspectives of community members and researchers. Findings suggest recruitment success occurs when there is a match between goals of Filipino parents, grandparents and the research community. Understanding the perspectives of ethnic minority communities and effectively communicating goals of research studies are critical to successful recruitment of hard-to-reach immigrant populations in randomized controlled trials.

A randomized trial of the impact of survey design characteristics on response rates among nursing home providers.

PubMed

Clark, Melissa; Rogers, Michelle; Foster, Andrew; Dvorchak, Faye; Saadeh, Frances; Weaver, Jessica; Mor, Vincent

2011-12-01

An experiment was conducted to maximize participation of both the Director of Nursing (DoN) and the Administrator (ADMIN) in long-term care facilities. Providers in each of the 224 randomly selected facilities were randomly assigned to 1 of 16 conditions based on the combination of data collection mode (web vs. mail), questionnaire length (short vs. long), and incentive structure. Incentive structures were determined by amount compensated if the individual completed and an additional amount per individual if the pair completed (a) $30 individual/$5 pair/$35 total; (b) $10 individual/$25 pair/$35 total; (c) $30 individual/$20 pair/$50 total; and (d) $10 individual/$40 pair/$50 total. Overall, 47.4% of eligible respondents participated; both respondents participated in 29.3% of facilities. In multivariable analyses, there were no differences in the likelihood of both respondents participating by mode, questionnaire length, or incentive structure. Providing incentives contingent on participation by both providers of a facility was an ineffective strategy for significantly increasing response rates.

The UAE Rainfall Enhancement Assessment Program: Implications of Thermodynamic Profiles on the Development of Precipitation in Convective Clouds over the Oman Mountains

NASA Astrophysics Data System (ADS)

Breed, D.; Bruintjes, R.; Jensen, T.; Salazar, V.; Fowler, T.

2005-12-01

During the winter and summer seasons of 2001 and 2002, data were collected to assess the efficacy of cloud seeding to enhance precipitation in the United Arab Emirates (UAE). The results of the feasibility study concluded: 1) that winter clouds in the UAE rarely produced conditions amenable to hygroscopic cloud seeding; 2) that summer convective clouds developed often enough, particularly over the Oman Mountains (e.g., the Hajar Mountains along the eastern UAE border and into Oman) to justify a randomized seeding experiment; 3) that collecting quantitative radar observations continues to be a complex but essential part of evaluating a cloud seeding experiment; 4) that successful flight operations would require solving several logistical issues; and 5) that several scientific questions would need to be studied in order to fully evaluate the efficacy and feasibility of hygroscopic cloud seeding, including cloud physical responses, radar-derived rainfall estimates as related to rainfall at the ground, and hydrological impacts. Based on these results, the UAE program proceeded through the design and implemention of a randomized hygroscopic cloud seeding experiment during the summer seasons to statistically quantify the potential for cloud seeding to enhance rainfall, specifically over the UAE and Oman Mountains, while collecting concurrent and separate physical measurements to support the statistical results and provide substantiation for the physical hypothesis. The randomized seeding experiment was carried out over the summers of 2003 and 2004, and a total of 134 cases were treated over the two summer seasons, of which 96 met the analysis criteria established in the experimental design of the program. The statistical evaluation of these cases yielded largely inconclusive results. Evidence will show that the thermodynamic profile had a large influence on storm characteristics and on precipitation development. This in turn provided a confounding factor in the conduct of the seeding experiment, particularly in the lateness of treatment in the storm cycle. The prevalence of capping inversions and the sensitivity of clouds to the level of the inversions as well as to wind shear will be shown using several data sets (soundings, aircraft, radar, numerical models). Concurrent physical measurements with the randomized experiment provided new insights into the physical processes of precipitation that developed in summertime convective clouds over the UAE that in turn helped in the interpretation of the statistical results.

A Comprehensive Lifestyle Randomized Clinical Trial: Design and Initial Patient Experience.

PubMed

Arun, Banu; Austin, Taylor; Babiera, Gildy V; Basen-Engquist, Karen; Carmack, Cindy L; Chaoul, Alejandro; Cohen, Lorenzo; Connelly, Lisa; Haddad, Robin; Harrison, Carol; Li, Yisheng; Mallaiah, Smitha; Nagarathna, Raghuram; Parker, Patricia A; Perkins, George H; Reuben, James M; Shih, Ya-Chen Tina; Spelman, Amy; Sood, Anil; Yang, Peiying; Yeung, Sai-Ching J

2017-03-01

Although epidemiological research demonstrates that there is an association between lifestyle factors and risk of breast cancer recurrence, progression of disease, and mortality, no comprehensive lifestyle change clinical trials have been conducted to determine if changing multiple risk factors leads to changes in biobehavioral processes and clinical outcomes in women with breast cancer. This article describes the design, feasibility, adherence to the intervention and data collection, and patient experience of a comprehensive lifestyle change clinical trial (CompLife). CompLife is a randomized, controlled trial of a multiple-behavior intervention focusing on diet, exercise, and mind-body practice along with behavioral counseling to support change. The initial exposure to the intervention takes place during the 4 to 6 weeks of radiotherapy (XRT) for women with stage III breast cancer and then across the subsequent 12 months. The intervention group will have 42 hours of in-person lifestyle counseling during XRT (7-10 hours a week) followed by up to 30 hours of counseling via video connection for the subsequent 12 months (weekly sessions for 6 months and then monthly for 6 months). The primary outcome is disease-free survival. Multiple secondary outcomes are being evaluated, including: (1) biological pathways; (2) overall survival; (3) patient-reported outcomes; (4) dietary patterns/fitness levels, anthropometrics, and body composition; and (5) economic outcomes. Qualitative data of the patient experience in the trial is collected from exit interviews, concluding remarks, direct email correspondences, and web postings from patients. Fifty-five patients have been recruited and randomized to the trial to date. Accrual of eligible patients is high (72%) and dropout rates extremely low (5%). Attendance to the in-person sessions is high (95% attending greater than 80% of sessions) as well as to the 30 hours of video counseling (88% attending more than 70% of sessions). Adherence to components of the behavior change intervention is high and compliance with the intensive amount of data collection is exceptional. Qualitative data collected from the participants reveals testimonials supporting the importance of the comprehensive nature of intervention, especially the mind-body/mindfulness component and social support, and meaningful lifestyle transformations. Conducting a comprehensive, multicomponent, lifestyle change clinical trial for women with breast was feasible and collection of biobehavioral outcomes successful. Adherence to behavior change was high and patient experience was overwhelmingly positive.

Recruitment and Enrollment for the Simultaneous Conduct of 2 Randomized Controlled Trials for Patients with Subacute and Chronic Low Back Pain at a CAM Research Center

PubMed Central

Long, Cynthia R.; Haan, Andrea G.; Spencer, Lori Byrd; Meeker, William C.

2008-01-01

Abstract Objective To describe recruitment and enrollment experiences of 2 low back pain (LBP) randomized controlled trials (RCTs). Design Descriptive report. Setting Chiropractic research center in the midwest United States that is not a fee-for-service clinic. Participants Both trials enrolled participants with subacute or chronic LBP without neurologic signs who had not received spinal manipulative care during the previous month. For study 1 we screened 1940 potential participants to enroll 192 participants (89 women and 103 men), mean age 40.0 ± 9.4 years (range, 21–54 years). For study 2 we screened 1849 potential participants to enroll 240 participants (105 women and 135 men) at least 55 years old (mean, 63.1 ± 6.7 years). Interventions Study 1 randomly assigned participants to 2 weeks of 2 different chiropractic techniques or a wait list control group. Study 2 randomly assigned participants to 6 weeks of 2 different chiropractic techniques or medical care consisting of 3 provider visits for medications. Outcome measures Recruitment source costs and yield, and baseline characteristics of enrolled versus nonparticipants were recorded. Results We conducted 3789 telephone screens for both trials to enroll 432 (11%) participants, at a cost in excess of $156,000 for recruitment efforts. The cost per call for all callers averaged $41, ranging from $4 to $300 based on recruitment method; for enrolled participants, the cost per call was $361, ranging from $33 to $750. Direct mail efforts accounted for 62% of all callers, 57% for enrolled participants, and had the second lowest cost per call for recruitment efforts. Conclusions It is important that complementary and alternative medicine (CAM) research can be successfully conducted at CAM institutions. However, the costs associated with recruitment efforts for studies conducted at CAM institutions may be higher than expected and many self-identified participants are users of the CAM therapy. Therefore, strategies for efficient recruitment methods and targeting nonusers of CAM therapies should be developed early for CAM trials. PMID:18990046

Building clinical trial capacity to develop a new treatment for multidrug-resistant tuberculosis.

PubMed

Tupasi, Thelma; Gupta, Rajesh; Danilovits, Manfred; Cirule, Andra; Sanchez-Garavito, Epifanio; Xiao, Heping; Cabrera-Rivero, Jose L; Vargas-Vasquez, Dante E; Gao, Mengqiu; Awad, Mohamed; Gentry, Leesa M; Geiter, Lawrence J; Wells, Charles D

2016-02-01

New drugs for infectious diseases often need to be evaluated in low-resource settings. While people working in such settings often provide high-quality care and perform operational research activities, they generally have less experience in conducting clinical trials designed for drug approval by stringent regulatory authorities. We carried out a capacity-building programme during a multi-centre randomized controlled trial of delamanid, a new drug for the treatment of multidrug-resistant tuberculosis. The programme included: (i) site identification and needs assessment; (ii) achieving International Conference on Harmonization - Good Clinical Practice (ICH-GCP) standards; (iii) establishing trial management; and (iv) increasing knowledge of global and local regulatory issues. Trials were conducted at 17 sites in nine countries (China, Egypt, Estonia, Japan, Latvia, Peru, the Philippines, the Republic of Korea and the United States of America). Eight of the 10 sites in low-resource settings had no experience in conducting the requisite clinical trials. Extensive capacity-building was done in all 10 sites. The programme resulted in improved local capacity in key areas such as trial design, data safety and monitoring, trial conduct and laboratory services. Clinical trials designed to generate data for regulatory approval require additional efforts beyond traditional research-capacity strengthening. Such capacity-building approaches provide an opportunity for product development partnerships to improve health systems beyond the direct conduct of the specific trial.

Trust as commodity: social value orientation affects the neural substrates of learning to cooperate

PubMed Central

Declerck, Carolyn H.; Emonds, Griet; Boone, Christophe

2017-01-01

Abstract Individuals differ in their motives and strategies to cooperate in social dilemmas. These differences are reflected by an individual’s social value orientation: proselfs are strategic and motivated to maximize self-interest, while prosocials are more trusting and value fairness. We hypothesize that when deciding whether or not to cooperate with a random member of a defined group, proselfs, more than prosocials, adapt their decisions based on past experiences: they ‘learn’ instrumentally to form a base-line expectation of reciprocity. We conducted an fMRI experiment where participants (19 proselfs and 19 prosocials) played 120 sequential prisoner’s dilemmas against randomly selected, anonymous and returning partners who cooperated 60% of the time. Results indicate that cooperation levels increased over time, but that the rate of learning was steeper for proselfs than for prosocials. At the neural level, caudate and precuneus activation were more pronounced for proselfs relative to prosocials, indicating a stronger reliance on instrumental learning and self-referencing to update their trust in the cooperative strategy. PMID:28119509

The Numerical Competency of Two Bird Species (Corvus splendens and Acridotheres tristis).

PubMed

Rahman, Nor Amira Abdul; Fadzly, Nik; Dzakwan, Najibah Mohd; Zulkifli, Nur Hazwani

2014-08-01

We conducted a series of experiments to test the numerical competency of two species of birds, Corvus splendens (House Crow) and Acridotheres tristis (Common Myna). Both species were allowed to choose from seven different groups of mealworms with varying proportions. We considered the birds to have made a correct choice when it selected the food group with the highest number of mealworms. Our overall results indicated that the Common Myna is able to count numbers (161 successful choices out of 247 trials) better than House Crows (133 successful choices out of 241 trials). We suspect that House Crows do not rely on a numerical sense when selecting food. Although House Crows mostly chose the cup with more mealworms (from seven food item proportions), only one proportion was chosen at rate above random chance. The Common Myna, however, were slow performers at the beginning but became increasingly more capable of numerical sense during the remainder of the experiment (four out of seven food proportion groups were chosen at a rate above random chance).

The Numerical Competency of Two Bird Species (Corvus splendens and Acridotheres tristis)

PubMed Central

Rahman, Nor Amira Abdul; Fadzly, Nik; Dzakwan, Najibah Mohd; Zulkifli, Nur Hazwani

2014-01-01

We conducted a series of experiments to test the numerical competency of two species of birds, Corvus splendens (House Crow) and Acridotheres tristis (Common Myna). Both species were allowed to choose from seven different groups of mealworms with varying proportions. We considered the birds to have made a correct choice when it selected the food group with the highest number of mealworms. Our overall results indicated that the Common Myna is able to count numbers (161 successful choices out of 247 trials) better than House Crows (133 successful choices out of 241 trials). We suspect that House Crows do not rely on a numerical sense when selecting food. Although House Crows mostly chose the cup with more mealworms (from seven food item proportions), only one proportion was chosen at rate above random chance. The Common Myna, however, were slow performers at the beginning but became increasingly more capable of numerical sense during the remainder of the experiment (four out of seven food proportion groups were chosen at a rate above random chance). PMID:25210590

Leisure education reduces stress among older adults.

PubMed

Chang, Liang-Chih

2014-01-01

The objectives of this study were to examine whether a leisure education program could facilitate leisure competence among older adults and whether it could also reduce their stress. A pre-test-post-test randomized experimental design was conducted. Subjects were randomly assigned to either an experimental group (n = 30) or a control group (n = 30). A leisure education program was used to serve as the intervention. A day before this experiment was carried out, pre-test data were collected using leisure competence and stress scales. Thirty minutes after this experiment ended, post-test data were collected using the same scales. These data were analyzed using an analysis of covariance. The results indicated that the average post-test scores of leisure competence in the experimental group were significantly higher than those in the control group and that the average post-test scores of stress in the experimental group were significantly lower than those in the control group. Healthcare practitioners should adopt the provision of leisure education as a priority to facilitate leisure competence and reduce stress among older adults.

Trust as commodity: social value orientation affects the neural substrates of learning to cooperate.

PubMed

Lambert, Bruno; Declerck, Carolyn H; Emonds, Griet; Boone, Christophe

2017-04-01

Individuals differ in their motives and strategies to cooperate in social dilemmas. These differences are reflected by an individual's social value orientation: proselfs are strategic and motivated to maximize self-interest, while prosocials are more trusting and value fairness. We hypothesize that when deciding whether or not to cooperate with a random member of a defined group, proselfs, more than prosocials, adapt their decisions based on past experiences: they 'learn' instrumentally to form a base-line expectation of reciprocity. We conducted an fMRI experiment where participants (19 proselfs and 19 prosocials) played 120 sequential prisoner's dilemmas against randomly selected, anonymous and returning partners who cooperated 60% of the time. Results indicate that cooperation levels increased over time, but that the rate of learning was steeper for proselfs than for prosocials. At the neural level, caudate and precuneus activation were more pronounced for proselfs relative to prosocials, indicating a stronger reliance on instrumental learning and self-referencing to update their trust in the cooperative strategy. © The Author (2017). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

Breakfast choice: An experiment combining a nutritional training workshop targeting adolescents and the promotion of unhealthy products

PubMed Central

Lopez‐Valcarcel, Beatriz G.

2017-01-01

Abstract A randomised control trial was conducted to determine changes in the food and drink choices of adolescents following their participation in a 50‐min nutrition workshop. The experiment was conducted at 104 schools in Barcelona (126 classes, 3,291 adolescents). Schools were randomly selected and stratified by district and by public or private status. The students were given three types of vouchers with different options regarding the type of food for which the vouchers could be exchanged (standard for healthy food and drink, two for one for unhealthy food, and two for one for unhealthy drink). Difference‐in‐differences linear models that control for individual, family, school or neighbourhood characteristics, and the influence of peers were applied. The probability of students' choosing unhealthy food and drink fell by 7.1% and 4.4%, respectively, following participation in the nutrition workshop. The promotion of unhealthy beverages counteracted the positive impact of the workshop on beverage choice. PMID:28744931

A comparison of traditional physical laboratory and computer-simulated laboratory experiences in relation to engineering undergraduate students' conceptual understandings of a communication systems topic

NASA Astrophysics Data System (ADS)

Javidi, Giti

2005-07-01

This study was designed to investigate an alternative to the use of traditional physical laboratory activities in a communication systems course. Specifically, this study examined whether as an alternative, computer simulation is as effective as physical laboratory activities in teaching college-level electronics engineering education students about the concepts of signal transmission, modulation and demodulation. Eighty undergraduate engineering students participated in the study, which was conducted at a southeastern four-year university. The students were randomly assigned to two groups. The groups were compared on understanding the concepts, remembering the concepts, completion time of the lab experiments and perception toward the laboratory experiments. The physical group's (n = 40) treatment was to conduct laboratory experiments in a physical laboratory. The students in this group used equipment in a controlled electronics laboratory. The Simulation group's (n = 40) treatment was to conduct similar experiments in a PC laboratory. The students in this group used a simulation program in a controlled PC lab. At the completion of the treatment, scores on a validated conceptual test were collected once after the treatment and again three weeks after the treatment. Attitude surveys and qualitative study were administered at the completion of the treatment. The findings revealed significant differences, in favor of the simulation group, between the two groups on both the conceptual post-test and the follow-up test. The findings also revealed significant correlation between simulation groups' attitude toward the simulation program and their post-test scores. Moreover, there was a significant difference between the two groups on their attitude toward their laboratory experience in favor of the simulation group. In addition, there was significant difference between the two groups on their lab completion time in favor of the simulation group. At the same time, the qualitative research has uncovered several issues not explored by the quantitative research. It was concluded that incorporating the recommendations acquired from the qualitative research, especially elements of incorporating hardware experience to avoid lack of hands-on skills, into the laboratory pedagogy should help improve students' experience regardless of the environment in which the laboratory is conducted.

Assessing the effectiveness and cost-effectiveness of audit and feedback on physician’s prescribing indicators: study protocol of a randomized controlled trial with economic evaluation

PubMed Central

2012-01-01

Background Physician prescribing is the most frequent medical intervention with a highest impact on healthcare costs and outcomes. Therefore improving and promoting rational drug use is a great interest. We aimed to assess the effectiveness and cost-effectiveness of two forms of conducting prescribing audit and feedback interventions and a printed educational material intervention in improving physician prescribing. Method/design A four-arm randomized trial with economic evaluation will be conducted in Tehran. Three interventions (routine feedback, revised feedback, and printed educational material) and a no intervention control arm will be compared. Physicians working in outpatient practices are randomly allocated to one of the four arms using stratified randomized sampling. The interventions are developed based on a review of literature, physician interviews, current experiences in Iran and with theoretical insights from the Theory of Planned Behavior. Effects of the interventions on improving antibiotics and corticosteroids prescribing will be assessed in regression analyses. Cost data will be assessed from a health care provider’s perspective and incremental cost-effectiveness ratios will be calculated. Discussion This study will determine the effectiveness and cost-effectiveness of three interventions and allow us to determine the most effective interventions in improving prescribing pattern. If the interventions are cost-effective, they will likely be applied nationwide. Trial registration Iranian Registry of Clinical Trials Registration Number: IRCT201106086740N1Pharmaceutical Sciences Research Center of TUMS Ethics Committee Registration Number: 90-02-27-07 PMID:23351564

Effectiveness of battlefield-ethics training during combat deployment: a programme assessment.

PubMed

Warner, Christopher H; Appenzeller, George N; Mobbs, Angela; Parker, Jessica R; Warner, Carolynn M; Grieger, Thomas; Hoge, Charles W

2011-09-03

Breakdowns in the ethical conduct of soldiers towards non-combatants on the battlefield are of grave concern in war. Evidence-based training approaches to prevent unethical conduct are scarce. We assessed the effectiveness of battlefield-ethics training and factors associated with unethical battlefield conduct. The training package, based on movie vignettes and leader-led discussions, was administered 7 to 8 months into a 15-month high-intensity combat deployment in Iraq, between Dec 11, 2007, and Jan 30, 2008. Soldiers from an infantry brigade combat team (total population about 3500) were randomly selected, on the basis of company and the last four digits of each soldier's social security number, and invited to complete an anonymous survey 3 months after completion of the training. Reports of unethical behaviour and attitudes in this sample were compared with a randomly selected pre-training sample from the same brigade. The response patterns for ethical behaviour and reporting of ethical violations were analysed with chi-square analyses. We developed two logistic regression models using self-reported unethical behaviours as dependent variables. Factors associated with unethical conduct, including combat experiences and post-traumatic stress disorder (PTSD), were assessed with validated scales. Of 500 randomly selected soldiers 421 agreed to participate in the anonymous post-training survey. A total of 397 soldiers of the same brigade completed the pre-training survey. Training was associated with significantly lower rates of unethical conduct of soldiers and greater willingness to report and address misconduct than in those before training. For example, reports of unnecessary damage or destruction of private property decreased from 13·6% (54 of 397; 95% CI 10·2-17·0) before training to 5·0% (21 of 421; 2·9-7·1) after training (percent difference -63·2%; p<0·0001), and willingness to report a unit member for mistreatment of a non-combatant increased from 36·0% (143 of 397; 31·3-40·7) to 58·9% (248 of 421; 54·2-63·6; percent difference 63·6; p<0·0001). Nearly all participants (410 [97%]) reported that training made it clear how to respond towards non-combatants. Combat frequency and intensity was the strongest predictor of unethical behaviour; PTSD was not a significant predictor of unethical behaviour after controlling for combat experiences. Leader-led battlefield ethics training positively influenced soldiers' understanding of how to interact with and treat non-combatants, and reduced reports of ethical misconduct. Unethical battlefield conduct was associated with high-intensity combat but not with PTSD. None. Copyright © 2011 Elsevier Ltd. All rights reserved.

Psilocybin occasioned mystical-type experiences: immediate and persisting dose-related effects.

PubMed

Griffiths, Roland R; Johnson, Matthew W; Richards, William A; Richards, Brian D; McCann, Una; Jesse, Robert

2011-12-01

This dose-effect study extends previous observations showing that psilocybin can occasion mystical-type experiences having persisting positive effects on attitudes, mood, and behavior. This double-blind study evaluated psilocybin (0, 5, 10, 20, 30 mg/70 kg, p.o.) administered under supportive conditions. Participants were 18 adults (17 hallucinogen-naïve). Five 8-h sessions were conducted individually for each participant at 1-month intervals. Participants were randomized to receive the four active doses in either ascending or descending order (nine participants each). Placebo was scheduled quasi-randomly. During sessions, volunteers used eyeshades and were instructed to direct their attention inward. Volunteers completed questionnaires assessing effects immediately after and 1 month after each session, and at 14 months follow-up. Psilocybin produced acute perceptual and subjective effects including, at 20 and/or 30 mg/70 kg, extreme anxiety/fear (39% of volunteers) and/or mystical-type experience (72% of volunteers). One month after sessions at the two highest doses, volunteers rated the psilocybin experience as having substantial personal and spiritual significance, and attributed to the experience sustained positive changes in attitudes, mood, and behavior, with the ascending dose sequence showing greater positive effects. At 14 months, ratings were undiminished and were consistent with changes rated by community observers. Both the acute and persisting effects of psilocybin were generally a monotonically increasing function of dose, with the lowest dose showing significant effects. Under supportive conditions, 20 and 30 mg/70 kg psilocybin occasioned mystical-type experiences having persisting positive effects on attitudes, mood, and behavior. Implications for therapeutic trials are discussed.

Is Virtual Reality Ready for Prime Time in the Medical Space? A Randomized Control Trial of Pediatric Virtual Reality for Acute Procedural Pain Management.

PubMed

Gold, Jeffrey I; Mahrer, Nicole E

2018-04-01

To conduct a randomized control trial to evaluate the feasibility and efficacy of virtual reality (VR) compared with standard of care (SOC) for reducing pain, anxiety, and improving satisfaction associated with blood draw in children ages 10-21 years. In total, 143 triads (patients, their caregiver, and the phlebotomist) were recruited in outpatient phlebotomy at a pediatric hospital and randomized to receive either VR or SOC when undergoing routine blood draw. Patients and caregivers completed preprocedural and postprocedural standardized measures of pain, anxiety, and satisfaction, and phlebotomists reported about the patient's experience during the procedure. Findings showed that VR significantly reduced acute procedural pain and anxiety compared with SOC. A significant interaction between patient-reported anxiety sensitivity and treatment condition indicated that patients undergoing routine blood draw benefit more from VR intervention when they are more fearful of physiological sensations related to anxiety. Patients and caregivers in the VR condition reported high levels of satisfaction with the procedure. VR is feasible, tolerated, and well-liked by patients, caregivers, and phlebotomists alike for routine blood draw. Given the immersive and engaging nature of the VR experience, VR has the capacity to act as a preventive intervention transforming the blood draw experience into a less distressing, potentially pain-free routine medical procedure, particularly for pediatric patients with high anxiety sensitivity. VR holds promise to reduce negative health outcomes for children and reduce distress in caregivers, while facilitating increased satisfaction and throughput in hectic outpatient phlebotomy clinics.

Does reviewing lead to better learning and decision making? Answers from a randomized stock market experiment.

PubMed

Wessa, Patrick; Holliday, Ian E

2012-01-01

The literature is not univocal about the effects of Peer Review (PR) within the context of constructivist learning. Due to the predominant focus on using PR as an assessment tool, rather than a constructivist learning activity, and because most studies implicitly assume that the benefits of PR are limited to the reviewee, little is known about the effects upon students who are required to review their peers. Much of the theoretical debate in the literature is focused on explaining how and why constructivist learning is beneficial. At the same time these discussions are marked by an underlying presupposition of a causal relationship between reviewing and deep learning. The purpose of the study is to investigate whether the writing of PR feedback causes students to benefit in terms of: perceived utility about statistics, actual use of statistics, better understanding of statistical concepts and associated methods, changed attitudes towards market risks, and outcomes of decisions that were made. We conducted a randomized experiment, assigning students randomly to receive PR or non-PR treatments and used two cohorts with a different time span. The paper discusses the experimental design and all the software components that we used to support the learning process: Reproducible Computing technology which allows students to reproduce or re-use statistical results from peers, Collaborative PR, and an AI-enhanced Stock Market Engine. The results establish that the writing of PR feedback messages causes students to experience benefits in terms of Behavior, Non-Rote Learning, and Attitudes, provided the sequence of PR activities are maintained for a period that is sufficiently long.

Expressed racial identity and hypertension in a telephone survey sample from Toronto and Vancouver, Canada: do socioeconomic status, perceived discrimination and psychosocial stress explain the relatively high risk of hypertension for Black Canadians?

PubMed

Veenstra, Gerry

2012-10-12

Canadian research on racial health inequalities that foregrounds socially constructed racial identities and social factors which can explain consequent racial health inequalities is rare. This paper adopts a social typology of salient racial identities in contemporary Canada, empirically documents consequent racial inequalities in hypertension in an original survey dataset from Toronto and Vancouver, Canada, and then attempts to explain the inequalities in hypertension with information on socioeconomic status, perceived experiences with institutionalized and interpersonal discrimination, and psychosocial stress. Telephone interviews were conducted in 2009 with 706 randomly selected adults living in the City of Toronto and 838 randomly selected adults living in the Vancouver Census Metropolitan Area. Bivariate analyses and logistic regression modeling were used to examine relationships between racial identity, hypertension, socio-demographic factors, socioeconomic status, perceived discrimination and psychosocial stress. The Black Canadians in the sample were the most likely to report major and routine discriminatory experiences and were the least educated and the poorest. Black respondents were significantly more likely than Asian, South Asian and White respondents to report hypertension controlling for age, immigrant status and city of residence. Of the explanatory factors examined in this study, only educational attainment explained some of the relative risk of hypertension for Black respondents. Most of the risk remained unexplained in the models. Consistent with previous Canadian research, socioeconomic status explained a small portion of the relatively high risk of hypertension documented for the Black respondents. Perceived experiences of discrimination both major and routine and self-reported psychosocial stress did not explain these racial inequalities in hypertension. Conducting subgroup analyses by gender, discerning between real and perceived experiences of discrimination and considering potentially moderating factors such as coping strategy and internalization of racial stereotypes are important issues to address in future Canadian racial inequalities research of this kind.

Challenges for consent and community engagement in the conduct of cluster randomized trial among school children in low income settings: experiences from Kenya.

PubMed

Okello, George; Jones, Caroline; Bonareri, Maureen; Ndegwa, Sarah N; McHaro, Carlos; Kengo, Juddy; Kinyua, Kevin; Dubeck, Margaret M; Halliday, Katherine E; Jukes, Matthew C H; Molyneux, Sassy; Brooker, Simon J

2013-05-16

There are a number of practical and ethical issues raised in school-based health research, particularly those related to obtaining consent from parents and assent from children. One approach to developing, strengthening, and supporting appropriate consent and assent processes is through community engagement. To date, much of the literature on community engagement in biomedical research has concentrated on community- or hospital-based research, with little documentation, if any, of community engagement in school-based health research. In this paper we discuss our experiences of consent, assent and community engagement in implementing a large school-based cluster randomized trial in rural Kenya. Data collected as part of a qualitative study investigating the acceptability of the main trial, focus group discussions with field staff, observations of practice and authors' experiences are used to: 1) highlight the challenges faced in obtaining assent/consent; and 2) strategies taken to try to both protect participant rights (including to refuse and to withdraw) and ensure the success of the trial. Early meetings with national, district and local level stakeholders were important in establishing their co-operation and support for the project. Despite this support, both practical and ethical challenges were encountered during consenting and assenting procedures. Our strategy for addressing these challenges focused on improving communication and understanding of the trial, and maintaining dialogue with all the relevant stakeholders throughout the study period. A range of stakeholders within and beyond schools play a key role in school based health trials. Community entry and information dissemination strategies need careful planning from the outset, and with on-going consultation and feedback mechanisms established in order to identify and address concerns as they arise. We believe our experiences, and the ethical and practical issues and dilemmas encountered, will be of interest for others planning to conduct school-based research in Africa. National Institute of Health NCT00878007.

Challenges for consent and community engagement in the conduct of cluster randomized trial among school children in low income settings: experiences from Kenya

PubMed Central

2013-01-01

Background There are a number of practical and ethical issues raised in school-based health research, particularly those related to obtaining consent from parents and assent from children. One approach to developing, strengthening, and supporting appropriate consent and assent processes is through community engagement. To date, much of the literature on community engagement in biomedical research has concentrated on community- or hospital-based research, with little documentation, if any, of community engagement in school-based health research. In this paper we discuss our experiences of consent, assent and community engagement in implementing a large school-based cluster randomized trial in rural Kenya. Methods Data collected as part of a qualitative study investigating the acceptability of the main trial, focus group discussions with field staff, observations of practice and authors’ experiences are used to: 1) highlight the challenges faced in obtaining assent/consent; and 2) strategies taken to try to both protect participant rights (including to refuse and to withdraw) and ensure the success of the trial. Results Early meetings with national, district and local level stakeholders were important in establishing their co-operation and support for the project. Despite this support, both practical and ethical challenges were encountered during consenting and assenting procedures. Our strategy for addressing these challenges focused on improving communication and understanding of the trial, and maintaining dialogue with all the relevant stakeholders throughout the study period. Conclusions A range of stakeholders within and beyond schools play a key role in school based health trials. Community entry and information dissemination strategies need careful planning from the outset, and with on-going consultation and feedback mechanisms established in order to identify and address concerns as they arise. We believe our experiences, and the ethical and practical issues and dilemmas encountered, will be of interest for others planning to conduct school-based research in Africa. Trial registration National Institute of Health NCT00878007 PMID:23680181

A direct broadcast satellite-audio experiment

NASA Technical Reports Server (NTRS)

Vaisnys, Arvydas; Abbe, Brian; Motamedi, Masoud

1992-01-01

System studies have been carried out over the past three years at the Jet Propulsion Laboratory (JPL) on digital audio broadcasting (DAB) via satellite. The thrust of the work to date has been on designing power and bandwidth efficient systems capable of providing reliable service to fixed, mobile, and portable radios. It is very difficult to predict performance in an environment which produces random periods of signal blockage, such as encountered in mobile reception where a vehicle can quickly move from one type of terrain to another. For this reason, some signal blockage mitigation techniques were built into an experimental DAB system and a satellite experiment was conducted to obtain both qualitative and quantitative measures of performance in a range of reception environments. This paper presents results from the experiment and some conclusions on the effectiveness of these blockage mitigation techniques.

Automobile ride quality experiments correlated to iso-weighted criteria

NASA Technical Reports Server (NTRS)

Healey, A. J.; Young, R. K.; Smith, C. C.

1975-01-01

As part of an overall study to evaluate the usefulness of ride quality criteria for the design of improved ground transportation systems an experiment was conducted involving subjective and objective measurement of ride vibrations found in an automobile riding over roadways of various roughness. Correlation of the results led to some very significant relationships between passenger rating and ride accelerations. The latter were collapsed using a frequency-weighted root mean square measure of the random vibration. The results suggest the form of a design criterion giving the relationship between ride vibration and acceptable automobile ride quality. Further the ride criterion is expressed in terms that relate to rides with which most people are familiar. The design of the experiment, the ride vibration data acquisition, the concept of frequency weighting and the correlations found between subjective and objective measurements are presented.

Effect of Random Thermal Spikes on Stirling Convertor Heater Head Reliability

NASA Technical Reports Server (NTRS)

Shah, Ashwin R.; Korovaichuk, Igor; Halford, Gary R.

2004-01-01

Onboard radioisotope power systems being developed to support future NASA exploration missions require reliable design lifetimes of up to 14 yr and beyond. The structurally critical heater head of the high-efficiency developmental Stirling power convertor has undergone extensive computational analysis of operating temperatures (up to 650 C), stresses, and creep resistance of the thin-walled Inconel 718 bill of material. Additionally, assessment of the effect of uncertainties in the creep behavior of the thin-walled heater head, the variation in the manufactured thickness, variation in control temperature, and variation in pressure on the durability and reliability were performed. However, it is possible for the heater head to experience rare incidences of random temperature spikes (excursions) of short duration. These incidences could occur randomly with random magnitude and duration during the desired mission life. These rare incidences could affect the creep strain rate and therefore the life. The paper accounts for these uncertainties and includes the effect of such rare incidences, random in nature, on the reliability. The sensitivities of variables affecting the reliability are quantified and guidelines developed to improve the reliability are outlined. Furthermore, the quantified reliability is being verified with test data from the accelerated benchmark tests being conducted at the NASA Glenn Research Center.

The persistence of the attentional bias to regularities in a changing environment.

PubMed

Yu, Ru Qi; Zhao, Jiaying

2015-10-01

The environment often is stable, but some aspects may change over time. The challenge for the visual system is to discover and flexibly adapt to the changes. We examined how attention is shifted in the presence of changes in the underlying structure of the environment. In six experiments, observers viewed four simultaneous streams of objects while performing a visual search task. In the first half of each experiment, the stream in the structured location contained regularities, the shapes in the random location were randomized, and gray squares appeared in two neutral locations. In the second half, the stream in the structured or the random location may change. In the first half of all experiments, visual search was facilitated in the structured location, suggesting that attention was consistently biased toward regularities. In the second half, this bias persisted in the structured location when no change occurred (Experiment 1), when the regularities were removed (Experiment 2), or when new regularities embedded in the original or novel stimuli emerged in the previously random location (Experiments 3 and 6). However, visual search was numerically but no longer reliably faster in the structured location when the initial regularities were removed and new regularities were introduced in the previously random location (Experiment 4), or when novel random stimuli appeared in the random location (Experiment 5). This suggests that the attentional bias was weakened. Overall, the results demonstrate that the attentional bias to regularities was persistent but also sensitive to changes in the environment.

Brain-Computer Interface Based on Generation of Visual Images

PubMed Central

Bobrov, Pavel; Frolov, Alexander; Cantor, Charles; Fedulova, Irina; Bakhnyan, Mikhail; Zhavoronkov, Alexander

2011-01-01

This paper examines the task of recognizing EEG patterns that correspond to performing three mental tasks: relaxation and imagining of two types of pictures: faces and houses. The experiments were performed using two EEG headsets: BrainProducts ActiCap and Emotiv EPOC. The Emotiv headset becomes widely used in consumer BCI application allowing for conducting large-scale EEG experiments in the future. Since classification accuracy significantly exceeded the level of random classification during the first three days of the experiment with EPOC headset, a control experiment was performed on the fourth day using ActiCap. The control experiment has shown that utilization of high-quality research equipment can enhance classification accuracy (up to 68% in some subjects) and that the accuracy is independent of the presence of EEG artifacts related to blinking and eye movement. This study also shows that computationally-inexpensive Bayesian classifier based on covariance matrix analysis yields similar classification accuracy in this problem as a more sophisticated Multi-class Common Spatial Patterns (MCSP) classifier. PMID:21695206

Effect of manure and plants spacing on yield and flavonoid content of Elephantopus scaber L.

NASA Astrophysics Data System (ADS)

Riyana, D.; Widiyastuti, Y.; Widodo, H.; Purwanto, E.; Samanhudi

2018-03-01

This experiment is aimed to observe the growth and flavonoid contain of Tapak Liman (Elephantopus scaber L.) with different manure types and plants spacing treatment. This experiment is conducted at Tegal Gede Village, Karanganyar District on June until August 2016. The analysis of secondary metabolism was done in B2P2TOOT, Tawangamangu. This experiment is conducted with Randomized Complete Block Design (RCBD) with two treatment factors, those are manure and plants spacing. Animal manure treatment had 3 levels, those are without manure, cow manure with 20 ton/ha dose, and chicken manure with 20 ton/ha dose. Plants spacing treatment had 3 phrase, those are 20 cm × 20 cm; 30 × 30 cm; 40 cm × 40 cm. The result of this experiment shows that chicken manure with 20 ton/ha dosage increase the development of leaves’ lengthiness, header’s diameter, plant’s fresh weight, and plant’s dry weight. Plants spacing 40 cm × 40 cm increase for the development of leaves’ lengthiness, header’s diameter, plant’s wet weight, and plant’s dry weight. The combination between chicken manure with 20 ton/ha dose and plants spacing 40 cm × 40cm treatments show the highest amount of tapak liman extract and alleged having the biggest amount of flavonoid substance.

Psychophysical studies of the performance of an image database retrieval system

NASA Astrophysics Data System (ADS)

Papathomas, Thomas V.; Conway, Tiffany E.; Cox, Ingemar J.; Ghosn, Joumana; Miller, Matt L.; Minka, Thomas P.; Yianilos, Peter N.

1998-07-01

We describe psychophysical experiments conducted to study PicHunter, a content-based image retrieval (CBIR) system. Experiment 1 studies the importance of using (a) semantic information, (2) memory of earlier input and (3) relative, rather than absolute, judgements of image similarity. The target testing paradigm is used in which a user must search for an image identical to a target. We find that the best performance comes from a version of PicHunter that uses only semantic cues, with memory and relative similarity judgements. Second best is use of both pictorial and semantic cues, with memory and relative similarity judgements. Most reports of CBIR systems provide only qualitative measures of performance based on how similar retrieved images are to a target. Experiment 2 puts PicHunter into this context with a more rigorous test. We first establish a baseline for our database by measuring the time required to find an image that is similar to a target when the images are presented in random order. Although PicHunter's performance is measurably better than this, the test is weak because even random presentation of images yields reasonably short search times. This casts doubt on the strength of results given in other reports where no baseline is established.

Random Assignment within Schools: Lessons Learned from the Teach for America Experiment

ERIC Educational Resources Information Center

Glazerman, Steven

2012-01-01

Randomized trials are a common way to provide rigorous evidence on the impacts of education programs. This article discusses the trade-offs associated with study designs that involve random assignment of students within schools and describes the experience from one such study of Teach for America (TFA). The TFA experiment faced challenges with…

Improving Generalizations from Experiments Using Propensity Score Subclassification: Assumptions, Properties, and Contexts

ERIC Educational Resources Information Center

Tipton, Elizabeth

2013-01-01

As a result of the use of random assignment to treatment, randomized experiments typically have high internal validity. However, units are very rarely randomly selected from a well-defined population of interest into an experiment; this results in low external validity. Under nonrandom sampling, this means that the estimate of the sample average…

Assessment of the geoavailability of trace elements from minerals in mine wastes: analytical techniques and assessment of selected copper minerals

USGS Publications Warehouse

Driscoll, Rhonda; Hageman, Phillip L.; Benzel, William M.; Diehl, Sharon F.; Adams, David T.; Morman, Suzette; Choate, LaDonna M.

2012-01-01

In this study, four randomly selected copper-bearing minerals were examined—azurite, malachite, bornite, and chalcopyrite. The objectives were to examine and enumerate the crystalline and chemical properties of each of the minerals, to determine which, if any, of the Cu-bearing minerals might adversely affect systems biota, and to provide a multi-procedure reference. Laboratory work included use of computational software for quantifying crystalline and amorphous material and optical and electron imaging instruments to model and project crystalline structures. Chemical weathering, human fluid, and enzyme simulation studies were also conducted. The analyses were conducted systematically: X-ray diffraction and microanalytical studies followed by a series of chemical, bio-leaching, and toxicity experiments.

Portraying mental illness and drug addiction as treatable health conditions: effects of a randomized experiment on stigma and discrimination.

PubMed

McGinty, Emma E; Goldman, Howard H; Pescosolido, Bernice; Barry, Colleen L

2015-02-01

Despite significant advances in treatment, stigma and discrimination toward persons with mental illness and drug addiction have remained constant in past decades. Prior work suggests that portraying other stigmatized health conditions (i.e., HIV/AIDS) as treatable can improve public attitudes toward those affected. Our study compared the effects of vignettes portraying persons with untreated and symptomatic versus successfully treated and asymptomatic mental illness and drug addiction on several dimensions of public attitudes about these conditions. We conducted a survey-embedded randomized experiment using a national sample (N = 3940) from an online panel. Respondents were randomly assigned to read one of ten vignettes. Vignette one was a control vignette, vignettes 2-5 portrayed individuals with untreated schizophrenia, depression, prescription pain medication addiction and heroin addiction, and vignettes 6-10 portrayed successfully treated individuals with the same conditions. After reading the randomly assigned vignette, respondents answered questions about their attitudes related to mental illness or drug addiction. Portrayals of untreated and symptomatic schizophrenia, depression, and heroin addiction heightened negative public attitudes toward persons with mental illness and drug addiction. In contrast, portrayals of successfully treated schizophrenia, prescription painkiller addiction, and heroin addiction led to less desire for social distance, greater belief in the effectiveness of treatment, and less willingness to discriminate against persons with these conditions. Portrayal of persons with successfully treated mental illness and drug addiction is a promising strategy for reducing stigma and discrimination toward persons with these conditions and improving public perceptions of treatment effectiveness. Copyright © 2014 Elsevier Ltd. All rights reserved.

A study of the influence of conductive paths and their directions in randomly generated conductor network.

NASA Astrophysics Data System (ADS)

Mandolesi, E.; Moorkamp, M.; Jones, A. G.

2014-12-01

Most electromagnetic (EM) geophysical methods focus on the electrical conductivity of rocks and sediments to determine the geological structure of the subsurface. Electric conductivity itself is measured in the laboratory with a wide range of instruments and techniques. These measurements seldom return a compatible result. The presence of partially-interconnected random pathways of electrically conductive materials in resistive hosts has been studied for decades, and recently with increasing interest. To comprehend which conductive mechanism scales from the microstructures up to field electrical conductivity measurements, two main branch of studies have been undertaken: statistical probability of having a conductive pathways and mixing laws. Several numerical approaches have been tested to understand the effects of interconnected pathways of conductors at field scale. Usually these studies were restricted in two ways: the sources are considered constant in time (i.e., DC) and the domain is, with few exception, two-dimensional. We simulated the effects of time-varying EM sources on the conductivity measured on the surface of a three-dimensional randomly generated body embedded in an uniform host by using electromagnetic induction equations. We modelled a two-phase mixture of resistive and conductive elements with the goal of comparing the conductivity measured on field scale with the one proper of the elements constituting the random rock, and to test how the internal structures influence the directionality of the responses. Moreover, we modelled data from randomly generated bodies characterized by coherent internal structures, to check the effect of the named structures on the anisotropy of the effective conductivity. We compared these values with the electrical conductivity limits predicted by Hashin-Shtrikman bounds and the effective conductivity predicted by the Archie's law, both cast in its classic form and in an updated that allow to take in account two materials. The same analysis was done for both the resistive and the conductive conductivity values for the anisotropic case.

Key Items to Get Right When Conducting a Randomized Controlled Trial in Education

ERIC Educational Resources Information Center

Coalition for Evidence-Based Policy, 2005

2005-01-01

This is a checklist of key items to get right when conducting a randomized controlled trial to evaluate an educational program or practice ("intervention"). It is intended as a practical resource for researchers and sponsors of research, describing items that are often critical to the success of a randomized controlled trial. A significant…

Effect of Educational Package on Lifestyle of Primiparous Mothers during Postpartum Period: A Randomized Controlled Clinical Trial

ERIC Educational Resources Information Center

Khodabandeh, Farzaneh; Mirghafourvand, Mojgan; KamaliFard, Mahin; Mohammad-Alizadeh-Charandabi, Sakineh; Asghari Jafarabadi, Mohammad

2017-01-01

A healthy lifestyle is important for mothers during the postpartum period. This study was conducted to determine the effects of a lifestyle educational package in primiparous women. This randomized clinical trial was conducted on 220 mothers assigned to two groups using block randomization. In the intervention group, the mothers received…

Heat conduction in periodic laminates with probabilistic distribution of material properties

NASA Astrophysics Data System (ADS)

Ostrowski, Piotr; Jędrysiak, Jarosław

2017-04-01

This contribution deals with a problem of heat conduction in a two-phase laminate made of periodically distributed micro-laminas along one direction. In general, the Fourier's Law describing the heat conduction in a considered composite has highly oscillating and discontinuous coefficients. Therefore, the tolerance averaging technique (cf. Woźniak et al. in Thermomechanics of microheterogeneous solids and structures. Monografie - Politechnika Łódzka, Wydawnictwo Politechniki Łódzkiej, Łódź, 2008) is applied. Based on this technique, the averaged differential equations for a tolerance-asymptotic model are derived and solved analytically for given initial-boundary conditions. The second part of this contribution is an investigation of the effect of material properties ratio ω of two components on the total temperature field θ, by the assumption that conductivities of micro-laminas are not necessary uniquely described. Numerical experiments (Monte Carlo simulation) are executed under assumption that ω is a random variable with a fixed probability distribution. At the end, based on the obtained results, a crucial hypothesis is formulated.

DG-IMEX Stochastic Galerkin Schemes for Linear Transport Equation with Random Inputs and Diffusive Scalings

DOE PAGES

Chen, Zheng; Liu, Liu; Mu, Lin

2017-05-03

In this paper, we consider the linear transport equation under diffusive scaling and with random inputs. The method is based on the generalized polynomial chaos approach in the stochastic Galerkin framework. Several theoretical aspects will be addressed. Additionally, a uniform numerical stability with respect to the Knudsen number ϵ, and a uniform in ϵ error estimate is given. For temporal and spatial discretizations, we apply the implicit–explicit scheme under the micro–macro decomposition framework and the discontinuous Galerkin method, as proposed in Jang et al. (SIAM J Numer Anal 52:2048–2072, 2014) for deterministic problem. Lastly, we provide a rigorous proof ofmore » the stochastic asymptotic-preserving (sAP) property. Extensive numerical experiments that validate the accuracy and sAP of the method are conducted.« less

A culturally tailored Internet cancer support group for Asian American breast cancer survivors: A randomized controlled pilot intervention study.

PubMed

Chee, Wonshik; Lee, Yaelim; Im, Eun-Ok; Chee, Eunice; Tsai, Hsiu-Min; Nishigaki, Masakazu; Yeo, Seon Ae; Schapira, Marilyn M; Mao, Jun James

2017-07-01

Introduction The necessity of culturally competent Internet Cancer Support Groups (ICSGs) for ethnic minorities has recently been highlighted in order to increase its attractiveness and usage. The purpose of this study was to determine the preliminary efficacy of a culturally tailored registered-nurse-moderated ICSG for Asian American breast cancer survivors in enhancing the women's breast cancer survivorship experience. Methods The study included two phases: (a) a usability test and an expert review; and (b) a randomized controlled pilot intervention study. The usability test was conducted among five Asian American breast cancer survivors using a one-month online forum, and the expert review was conducted among five experts using the Cognitive Walkthrough method. The randomized controlled pilot intervention study (a pre-test and post-test design) was conducted among 65 Asian American breast cancer survivors. The data were analysed using content analysis and descriptive and inferential statistics including the repeated ANOVA. Results All users and experts positively evaluated the program and provided their suggestions for the display, educational contents, and user-friendly structure. There were significant positive changes in the support care needs and physical and psychological symptoms ( p < 0.05) of the control group. There were significant negative changes in the uncertainty level of the intervention group ( p < 0.10). Controlling for background and disease factors, the intervention group showed significantly greater improvements than the control group in physical and psychological symptoms and quality of life ( p < 0.10). Discussion The findings supported the positive effects of ICSGs on support care needs, psychological and physical symptoms, and quality of life.

Feasibility study of a randomized controlled trial of a telephone-delivered problem-solving-occupational therapy intervention to reduce participation restrictions in rural breast cancer survivors undergoing chemotherapy.

PubMed

Hegel, Mark T; Lyons, Kathleen D; Hull, Jay G; Kaufman, Peter; Urquhart, Laura; Li, Zhongze; Ahles, Tim A

2011-10-01

Breast cancer patients receiving adjuvant chemotherapy often experience functional effects of treatment that limit participation in life activities. The purpose of this study was to examine the feasibility of conducting a randomized controlled trial (RCT) of a novel intervention for these restrictions, determine acceptability of the intervention, and preliminarily assess its effects. A pilot RCT of a telephone-delivered Problem-solving and Occupational Therapy intervention (PST-OT) to improve participation restrictions in rural breast cancer patients undergoing chemotherapy. Thirty-one participants with Stages 1-3 breast cancer were randomized to 6 weekly sessions of PST-OT (n = 15) and usual care (n = 16). The primary study outcome was the feasibility of conducting the trial. Secondary outcomes were functional, quality of life and emotional status as assessed at baseline, 6 and 12 weeks. Of 46 patients referred 31 were enrolled (67% recruitment rate), of which 6 participants withdrew (81% retention rate). Twenty-four participants completed all study-related assessments (77%). Ninety-two percent of PST-OT participants were highly satisfied with the intervention, and 92% reported PST-OT to be helpful/very helpful for overcoming participation restrictions. Ninety-seven percent of planned PST-OT treatment sessions were completed. Completion rates for PST-OT homework tasks were high. Measures of functioning, quality of life, and emotional state favored the PST-OT condition. This pilot study suggests that an RCT of the PST-OT intervention is feasible to conduct with rural breast cancer patients undergoing adjuvant chemotherapy and that PST-OT may have positive effects on function, quality of life, and emotional state. 2010 John Wiley & Sons, Ltd.

"Open mesh" or "strictly selected population" recruitment? The experience of the randomized controlled MeMeMe trial.

PubMed

Cortellini, Mauro; Berrino, Franco; Pasanisi, Patrizia

2017-01-01

Among randomized controlled trials (RCTs), trials for primary prevention require large samples and long follow-up to obtain a high-quality outcome; therefore the recruitment process and the drop-out rates largely dictate the adequacy of the results. We are conducting a Phase III trial on persons with metabolic syndrome to test the hypothesis that comprehensive lifestyle changes and/or metformin treatment prevents age-related chronic diseases (the MeMeMe trial, EudraCT number: 2012-005427-32, also registered on ClinicalTrials.gov [NCT02960711]). Here, we briefly analyze and discuss the reasons which may lead to participants dropping out from trials. In our experience, participants may back out of a trial for different reasons. Drug-induced side effects are certainly the most compelling reason. But what are the other reasons, relating to the participants' perception of the progress of the trial which led them to withdraw after randomization? What about the time-dependent drop-out rate in primary prevention trials? The primary outcome of this analysis is the point of drop-out from trial, defined as the time from the randomization date to the withdrawal date. Survival functions were non-parametrically estimated using the product-limit estimator. The curves were statistically compared using the log-rank test ( P =0.64, not significant). Researchers involved in primary prevention RCTs seem to have to deal with the paradox of the proverbial "short blanket syndrome". Recruiting only highly motivated candidates might be useful for the smooth progress of the trial but it may lead to a very low enrollment rate. On the other hand, what about enrolling all the eligible subjects without considering their motivation? This might boost the enrollment rate, but it can lead to biased results on account of large proportions of drop-outs. Our experience suggests that participants do not change their mind depending on the allocation group (intervention or control). There is no single answer to sort out the short blanket syndrome.

Rescaling quality of life values from discrete choice experiments for use as QALYs: a cautionary tale

PubMed Central

Flynn, Terry N; Louviere, Jordan J; Marley, Anthony AJ; Coast, Joanna; Peters, Tim J

2008-01-01

Background Researchers are increasingly investigating the potential for ordinal tasks such as ranking and discrete choice experiments to estimate QALY health state values. However, the assumptions of random utility theory, which underpin the statistical models used to provide these estimates, have received insufficient attention. In particular, the assumptions made about the decisions between living states and the death state are not satisfied, at least for some people. Estimated values are likely to be incorrectly anchored with respect to death (zero) in such circumstances. Methods Data from the Investigating Choice Experiments for the preferences of older people CAPability instrument (ICECAP) valuation exercise were analysed. The values (previously anchored to the worst possible state) were rescaled using an ordinal model proposed previously to estimate QALY-like values. Bootstrapping was conducted to vary artificially the proportion of people who conformed to the conventional random utility model underpinning the analyses. Results Only 26% of respondents conformed unequivocally to the assumptions of conventional random utility theory. At least 14% of respondents unequivocally violated the assumptions. Varying the relative proportions of conforming respondents in sensitivity analyses led to large changes in the estimated QALY values, particularly for lower-valued states. As a result these values could be either positive (considered to be better than death) or negative (considered to be worse than death). Conclusion Use of a statistical model such as conditional (multinomial) regression to anchor quality of life values from ordinal data to death is inappropriate in the presence of respondents who do not conform to the assumptions of conventional random utility theory. This is clearest when estimating values for that group of respondents observed in valuation samples who refuse to consider any living state to be worse than death: in such circumstances the model cannot be estimated. Only a valuation task requiring respondents to make choices in which both length and quality of life vary can produce estimates that properly reflect the preferences of all respondents. PMID:18945358

Having "The Talk": Youth-Parent Climate Conversations

NASA Astrophysics Data System (ADS)

Anderson, R. K.; Flora, J. A.; Lertzman, R.; Saphir, M.

2017-12-01

Youth are concerned about climate change. Recent research conducted by the Alliance for Climate Education, in partnership with the Skoll Global Threats Fund, demonstrates that youth have agency within their families regarding climate relevant behaviors, particularly resulting from conversations that rely on listening. In this pilot project, we examined whether youth involved in a year-long climate action program will carry out climate related conversations with their parents, and whether youth who have engaged online with a climate education group, will carry out similar conversations with their parents when asked to do so via SMS. In study one, we used mixed methods to determine if youth participating in a training would carry out a climate conversation with their parents, adhere to guidelines such as reflective listening, and have positive experiences. Further, we investigated to what extent parents would experience the conversation as a positive and impactful event. Parents overall reported a positive experience, and were proud of their child's work. In study two, in a randomized controlled trial conducted entirely via SMS, we investigated whether youth would watch a brief instructional animated video, and have a conversation with a parent. Results showed the majority of youth reported gained confidence in conducting a climate conversation and intended to speak to relatives. Preliminary results indicate when youth can express their climate engagement to a parent using these techniques, they have positive experiences, gain confidence in future engagements and can influence family. The studies highlight the positive impact of climate conversations as well as the potential to scale climate conversations to reach more youth and families.

Metformin monotherapy in youth with recent onset type 2 diabetes: experience from the pre-randomization run-in phase of the TODAY study

PubMed Central

Laffel, Lori; Chang, Nancy; Grey, Margaret; Hale, Dan; Higgins, Laurie; Hirst, Kathryn; Izquierdo, Roberto; Larkin, Mary; Macha, Christina; Pham, Trang; Wauters, Aimee; Weinstock, Ruth S.

2011-01-01

Background TODAY (Treatment Options for type 2 Diabetes in Adolescents and Youth) is a federally-funded multi-center randomized clinical trial comparing three treatments of youth-onset type 2 diabetes. Objective To describe the experience of youth participating in a 2–6 month run-in period in preparation for randomization into TODAY. Subjects An ethnically diverse sample of 927 youth, 65.4% female, aged 13.7±2.0 years old, with type 2 diabetes for a median of 2 months (0.7–7.8 months, 25th-75th percentiles). Methods A run-in period was conducted to achieve HbA1c <8% with metformin monotherapy and diabetes education, and to evaluate adherence to pill taking, visit attendance, and other procedures. Results At entry, mean BMI and z-BMI were 35.6±7.7 and 2.3±0.4, respectively, mean HbA1c was 7.7±2.2%, only 42.5% were on a hypoglycemic treatment, and 35.6% had HbA1c ≥8%. Co-morbid conditions were common; 18.8% had hypertension, 24.2% had elevated cholesterol, and 6.5% had abnormal liver enzymes. After a median 71 days of run-in, 90.9% had HbA1c <8%, 77.9% had HbA1c <7%, and 46.4% had HbA1c <6%. Of the 772 youth achieving the target HbA1c <8%, 704 (91.2%) were randomized; non-adherence to metformin treatment was the main cause for non-randomization. Youth proceeding to randomization decreased weight by 0.68 kg and HbA1c by 1.45% compared to a weight gain of 0.71 kg and HbA1c decrease of 0.74% in the non-randomized youth (p=0.01 in both cases). Change in z-BMI was not significantly different between the two groups, however. Conclusions Most youth with recent onset type 2 diabetes can achieve target HbA1c <8.0% with short-term metformin monotherapy and standard diabetes education. PMID:22369102

Impact of isotopic disorders on thermal transport properties of nanotubes and nanowires

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

Sun, Tao; Kang, Wei; Wang, Jianxiang, E-mail: jxwang@pku.edu.cn

2015-01-21

We present a one-dimensional lattice model to describe thermal transport in isotopically doped nanotubes and nanowires. The thermal conductivities thus predicted, as a function of isotopic concentration, agree well with recent experiments and other simulations. Our results display that for any given concentration of isotopic atoms in a lattice without sharp atomic interfaces, the maximum thermal conductivity is attained when isotopic atoms are placed regularly with an equal space, whereas the minimum is achieved when they are randomly inserted with a uniform distribution. Non-uniformity of disorder can further tune the thermal conductivity between the two values. Moreover, the dependence ofmore » the thermal conductivity on the nanoscale feature size becomes weak at low temperature when disorder exists. In addition, when self-consistent thermal reservoirs are included to describe diffusive nanomaterials, the thermal conductivities predicted by our model are in line with the results of macroscopic theories with an interfacial effect. Our results suggest that the disorder provides an additional freedom to tune the thermal properties of nanomaterials in many technological applications including nanoelectronics, solid-state lighting, energy conservation, and conversion.« less

How Cannabis Causes Paranoia: Using the Intravenous Administration of ∆9-Tetrahydrocannabinol (THC) to Identify Key Cognitive Mechanisms Leading to Paranoia

PubMed Central

Freeman, Daniel; Dunn, Graham; Murray, Robin M.; Evans, Nicole; Lister, Rachel; Antley, Angus; Slater, Mel; Godlewska, Beata; Cornish, Robert; Williams, Jonathan; Di Simplicio, Martina; Igoumenou, Artemis; Brenneisen, Rudolf; Tunbridge, Elizabeth M.; Harrison, Paul J.; Harmer, Catherine J.; Cowen, Philip; Morrison, Paul D.

2015-01-01

Paranoia is receiving increasing attention in its own right, since it is a central experience of psychotic disorders and a marker of the health of a society. Paranoia is associated with use of the most commonly taken illicit drug, cannabis. The objective was to determine whether the principal psychoactive ingredient of cannabis—∆9-tetrahydrocannabinol (THC)—causes paranoia and to use the drug as a probe to identify key cognitive mechanisms underlying paranoia. A randomized, placebo-controlled, between-groups test of the effects of intravenous THC was conducted. A total of 121 individuals with paranoid ideation were randomized to receive placebo, THC, or THC preceded by a cognitive awareness condition. Paranoia was assessed extensively via a real social situation, an immersive virtual reality experiment, and standard self-report and interviewer measures. Putative causal factors were assessed. Principal components analysis was used to create a composite paranoia score and composite causal variables to be tested in a mediation analysis. THC significantly increased paranoia, negative affect (anxiety, worry, depression, negative thoughts about the self), and a range of anomalous experiences, and reduced working memory capacity. The increase in negative affect and in anomalous experiences fully accounted for the increase in paranoia. Working memory changes did not lead to paranoia. Making participants aware of the effects of THC had little impact. In this largest study of intravenous THC, it was definitively demonstrated that the drug triggers paranoid thoughts in vulnerable individuals. The most likely mechanism of action causing paranoia was the generation of negative affect and anomalous experiences. PMID:25031222

Setting the stage for chronic health problems: cumulative childhood adversity among homeless adults with mental illness in Vancouver, British Columbia.

PubMed

Patterson, Michelle L; Moniruzzaman, Akm; Somers, Julian M

2014-04-12

It is well documented that childhood abuse, neglect and household dysfunction are disproportionately present in the backgrounds of homeless adults, and that these experiences adversely impact child development and a wide range of adult outcomes. However, few studies have examined the cumulative impact of adverse childhood experiences on homeless adults with mental illness. This study examines adverse events in childhood as predictors of duration of homelessness, psychiatric and substance use disorders, and physical health in a sample of homeless adults with mental illness. This study was conducted using baseline data from a randomized controlled trial in Vancouver, British Columbia for participants who completed the Adverse Childhood Experiences (ACE) scale at 18 months follow-up (n=364). Primary outcomes included current mental disorders; substance use including type, frequency and severity; physical health; duration of homelessness; and vocational functioning. In multivariable regression models, ACE total score independently predicted a range of mental health, physical health, and substance use problems, and marginally predicted duration of homelessness. Adverse childhood experiences are overrepresented among homeless adults with complex comorbidities and chronic homelessness. Our findings are consistent with a growing body of literature indicating that childhood traumas are potent risk factors for a number of adult health and psychiatric problems, particularly substance use problems. Results are discussed in the context of cumulative adversity and self-trauma theory. This trial has been registered with the International Standard Randomized Control Trial Number Register and assigned ISRCTN42520374.

"You gotta try it all": Parents' Experiences with Robotic Gait Training for their Children with Cerebral Palsy.

PubMed

Beveridge, Briony; Feltracco, Deanna; Struyf, Jillian; Strauss, Emily; Dang, Saniya; Phelan, Shanon; Wright, F Virginia; Gibson, Barbara E

2015-01-01

Innovative robotic technologies hold strong promise for improving walking abilities of children with cerebral palsy (CP), but may create expectations for parents pursuing the "newest thing" in treatment. The aim of this qualitative study was to explore parents' values about walking in relation to their experiences with robotic gait training for their children. Semi-structured interviews were conducted with parents of five ambulatory children with CP participating in a randomized trial investigating robotic gait training effectiveness. Parents valued walking, especially "correct" walking, as a key component of their children's present and future well-being. They continually sought the "next best thing" in therapy and viewed the robotic gait trainer as a potentially revolutionary technology despite mixed experiences. The results can help inform rehabilitation therapists' knowledge of parents' values and perspectives, and guide effective collaborations toward meeting the therapeutic needs of children with CP.

Race, Racial Discrimination, and the Risk of Work-Related Illness, Injury or Assault: Findings from a National Study

PubMed Central

Shannon, Candice A.; Rospenda, Kathleen M.; Richman, Judith A.; Minich, Lisa M.

2014-01-01

Objective: This study examines whether workplace racial harassment/discrimination mediates the relationship between race/ethnicity and work-related illness, injury or assault across time. Methods: A national random-digit dial phone survey was conducted at two points in time (W1: 2003-2004; W2: 2004-2005) among a sample of Black, Hispanic and non-Hispanic white workers. As part of the survey, respondents indicated their experiences with racial harassment or discrimination, and occupational illness, injury, or assault in the past 12 months. Results: Hispanic respondents were more likely than whites to experience work-related illness, injury or assault, and these associations were mediated by experiences of racial harassment/discrimination. Conclusions: Interventions to reduce workplace harassment and discrimination may help decrease risk for work-related illness, injury, or assault among Hispanic workers. PMID:19339900

ARCADO - Adding random case analysis to direct observation in workplace-based formative assessment of general practice registrars.

PubMed

Ingham, Gerard; Fry, Jennifer; Morgan, Simon; Ward, Bernadette

2015-12-10

Workplace-based formative assessments using consultation observation are currently conducted during the Australian general practice training program. Assessment reliability is improved by using multiple assessment methods. The aim of this study was to explore experiences of general practice medical educator assessors and registrars (trainees) when adding random case analysis to direct observation (ARCADO) during formative workplace-based assessments. A sample of general practice medical educators and matched registrars were recruited. Following the ARCADO workplace assessment, semi-structured qualitative interviews were conducted. The data was analysed thematically. Ten registrars and eight medical educators participated. Four major themes emerged - formative versus summative assessment; strengths (acceptability, flexibility, time efficiency, complementarity and authenticity); weaknesses (reduced observation and integrity risks); and contextual factors (variation in assessment content, assessment timing, registrar-medical educator relationship, medical educator's approach and registrar ability). ARCADO is a well-accepted workplace-based formative assessment perceived by registrars and assessors to be valid and flexible. The use of ARCADO enabled complementary insights that would not have been achieved with direct observation alone. Whilst there are some contextual factors to be considered in its implementation, ARCADO appears to have utility as formative assessment and, subject to further evaluation, high-stakes assessment.

Random Assignment: Practical Considerations from Field Experiments.

ERIC Educational Resources Information Center

Dunford, Franklyn W.

1990-01-01

Seven qualitative issues associated with randomization that have the potential to weaken or destroy otherwise sound experimental designs are reviewed and illustrated via actual field experiments. Issue areas include ethics and legality, liability risks, manipulation of randomized outcomes, hidden bias, design intrusiveness, case flow, and…

Psilocybin occasioned mystical-type experiences: Immediate and persisting dose-related effects

PubMed Central

Griffiths, R. R.; Johnson, M.W.; Richards, W. A.; Richards, B.D.; McCann, U.; Jesse, R.

2012-01-01

Rationale This dose-effect study extends previous observations showing that psilocybin can occasion mystical-type experiences having persisting positive effects on attitudes, mood, and behavior. Objectives This double-blind study evaluated psilocybin (0, 5, 10, 20, 30 mg/70 kg, p.o.) administered under supportive conditions. Methods Participants were 18 adults (17 hallucinogen-naïve). Five 8-hour sessions were conducted individually for each participant at 1-month intervals. Participants were randomized to receive the four active doses in either ascending or descending order (9 participants each). Placebo was scheduled quasi-randomly. During sessions volunteers used eyeshades and were instructed to direct their attention inward. Volunteers completed questionnaires assessing effects immediately after and 1 month after each session, and at 14 months follow-up. Results Psilocybin produced acute perceptual and subjective effects including, at 20 and/or 30 mg/70 kg, extreme anxiety/fear (39% of volunteers) and/or mystical-type experience (72% of volunteers). One month after sessions at the two highest doses, volunteers rated the psilocybin experience as having substantial personal and spiritual significance, and attributed to the experience sustained positive changes in attitudes, mood, and behavior, with the ascending dose sequence showing greater positive effects. At 14 months, ratings were undiminished and were consistent with changes rated by community observers. Both the acute and persisting effects of psilocybin were generally a monotonically increasing function of dose, with the lowest dose showing significant effects. Conclusions Under supportive conditions, 20 and 30 mg/70 kg psilocybin occasioned mystical-type experiences having persisting positive effects on attitudes, mood and behavior. Implications for therapeutic trials are discussed. PMID:21674151

Cognitive Behavior Therapy as Augmentation for Sertraline in Treating Patients with Persistent Postural-Perceptual Dizziness.

PubMed

Yu, Yi-Chuan; Xue, Hui; Zhang, Ying-Xin; Zhou, Jiying

2018-01-01

Persistent postural-perceptual dizziness (PPPD) is a common vestibular disorder. This study was conducted to assess whether the addition of cognitive behavior therapy (CBT) could significantly improve the efficacy and acceptability of sertraline in treating PPPD. PPPD patients were recruited and randomly assigned to control and experiment groups. Patients in both groups received sertraline 50-200 mg/day, and only patients in the experiment group received CBT (twice a week, one hour per time). The treatment was continued for eight weeks. At baseline, week 2, week 4, and week 8, the 25-item Dizziness Handicap Inventory (DHI), Hamilton Anxiety Rating Scale (HARS), and Hamilton Depression Rating Scale (HDRS) were used to assess the self-perceived handicapping effects caused by PPPD, anxiety, and depressive symptoms, respectively. The dose of sertraline used and the adverse events in both groups were recorded and analyzed. In total, 91 PPPD patients were randomly assigned to the control group ( n = 45) and experiment group ( n = 46). After eight weeks of treatment, the average DHI scores, HDRS scores, and HARS scores were significantly decreased in both groups. But compared to the control group, the experiment group had significantly lower average DHI score, HDRS score, and HARS score at weeks 4 and 8. Moreover, the dose of sertraline used in the experiment group was significantly lower than that in the control group, and adverse events occurred more frequently in the control group than in the experiment group (48.9% versus 26.1%, p = 0.025). These results demonstrated that the addition of CBT could significantly improve the efficacy and acceptability of sertraline in treating PPPD and reduce the dose of sertraline used.

Blocking for Sequential Political Experiments

PubMed Central

Moore, Sally A.

2013-01-01

In typical political experiments, researchers randomize a set of households, precincts, or individuals to treatments all at once, and characteristics of all units are known at the time of randomization. However, in many other experiments, subjects “trickle in” to be randomized to treatment conditions, usually via complete randomization. To take advantage of the rich background data that researchers often have (but underutilize) in these experiments, we develop methods that use continuous covariates to assign treatments sequentially. We build on biased coin and minimization procedures for discrete covariates and demonstrate that our methods outperform complete randomization, producing better covariate balance in simulated data. We then describe how we selected and deployed a sequential blocking method in a clinical trial and demonstrate the advantages of our having done so. Further, we show how that method would have performed in two larger sequential political trials. Finally, we compare causal effect estimates from differences in means, augmented inverse propensity weighted estimators, and randomization test inversion. PMID:24143061

Effect of a Website That Presents Patients’ Experiences on Self-Efficacy and Patient Competence of Colorectal Cancer Patients: Web-Based Randomized Controlled Trial

PubMed Central

Giesler, Jürgen M; Keller, Bettina; Repke, Tim; Leonhart, Rainer; Weis, Joachim; Muckelbauer, Rebecca; Rieckmann, Nina; Müller-Nordhorn, Jacqueline; Lucius-Hoene, Gabriele

2017-01-01

Background Patients often seek other patients’ experiences with the disease. The Internet provides a wide range of opportunities to share and learn about other people’s health and illness experiences via blogs or patient-initiated online discussion groups. There also exists a range of medical information devices that include experiential patient information. However, there are serious concerns about the use of such experiential information because narratives of others may be powerful and pervasive tools that may hinder informed decision making. The international research network DIPEx (Database of Individual Patients’ Experiences) aims to provide scientifically based online information on people’s experiences with health and illness to fulfill patients’ needs for experiential information, while ensuring that the presented information includes a wide variety of possible experiences. Objective The aim is to evaluate the colorectal cancer module of the German DIPEx website krankheitserfahrungen.de with regard to self-efficacy for coping with cancer and patient competence. Methods In 2015, a Web-based randomized controlled trial was conducted using a two-group between-subjects design and repeated measures. The study sample consisted of individuals who had been diagnosed with colorectal cancer within the past 3 years or who had metastasis or recurrent disease. Outcome measures included self-efficacy for coping with cancer and patient competence. Participants were randomly assigned to either an intervention group that had immediate access to the colorectal cancer module for 2 weeks or to a waiting list control group. Outcome criteria were measured at baseline before randomization and at 2 weeks and 6 weeks Results The study randomized 212 persons. On average, participants were 54 (SD 11.1) years old, 58.8% (124/211) were female, and 73.6% (156/212) had read or heard stories of other patients online before entering the study, thus excluding any influence of the colorectal cancer module on krankheitserfahrungen.de. No intervention effects were found at 2 and 6 weeks after baseline. Conclusions The results of this study do not support the hypothesis that the website studied may increase self-efficacy for coping with cancer or patient competencies such as self-regulation or managing emotional distress. Possible explanations may involve characteristics of the website itself, its use by participants, or methodological reasons. Future studies aimed at evaluating potential effects of websites providing patient experiences on the basis of methodological principles such as those of DIPEx might profit from extending the range of outcome measures, from including additional measures of website usage behavior and users’ motivation, and from expanding concepts, such as patient competency to include items that more directly reflect patients’ perceived effects of using such a website. Trial Registration Clinicaltrials.gov NCT02157454; https://clinicaltrials.gov/ct2/show/NCT02157454 (Archived by WebCite at http://www.webcitation.org/6syrvwXxi) PMID:29030329

Triple dissociation of duration perception regulating mechanisms: Top-down attention is inherent.

PubMed

Lin, Yong-Jun; Shimojo, Shinsuke

2017-01-01

The brain constantly adjusts perceived duration based on the recent event history. One such lab phenomenon is subjective time expansion induced in an oddball paradigm ("oddball chronostasis"), where the duration of a distinct item (oddball) appears subjectively longer when embedded in a series of other repeated items (standards). Three hypotheses have been separately proposed but it remains unresolved which or all of them are true: 1) attention prolongs oddball duration, 2) repetition suppression reduces standards duration, and 3) accumulative temporal preparation (anticipation) expedites the perceived item onset so as to lengthen its duration. We thus conducted critical systematic experiments to dissociate the relative contribution of all hypotheses, by orthogonally manipulating sequences types (repeated, ordered, or random) and target serial positions. Participants' task was to judge whether a target lasts shorter or longer than its reference. The main finding was that a random item sequence still elicited significant chronostasis even though each item was odd. That is, simply being a target draws top-down attention and induces chronostasis. In Experiments 1 (digits) and 2 (orientations), top-down attention explained about half of the effect while saliency/adaptation explained the other half. Additionally, for non-repeated (ordered and random) sequence types, a target with later serial position still elicited stronger chronostasis, favoring a temporal preparation over a repetition suppression account. By contrast, in Experiment 3 (colors), top-down attention was likely the sole factor. Consequently, top-down attention is necessary and sometimes sufficient to explain oddball chronostasis; saliency/adaptation and temporal preparation are contingent factors. These critical boundary conditions revealed in our study serve as quantitative constraints for neural models of duration perception.

Early Compared With Delayed Physician Rounds on Patient Satisfaction of Postpartum Women: A Randomized Controlled Trial.

PubMed

Roberts, Robyn P; Blackwell, Sean C; Brown, Kelly M; Pedroza, Claudia; Sibai, Baha M; Tyson, Jon E

2016-08-01

To investigate whether delayed timing of physician rounds improves patient satisfaction for postpartum women. Women were randomized to early (5-7 AM) or delayed (8-10 AM) physician rounding. Women with stillbirth, high-risk pregnancy, or complications precluding delayed rounding were excluded. At discharge, women completed a modified Hospital Consumer Assessment of Healthcare Providers and Systems survey. The primary outcome was rating of the hospital. Secondary outcomes included patient assessment of patient-physician communication, various hospital experiences, and timing of maternal and neonatal discharge. We estimated that 74 women were needed to detect a 20% difference in rating of the hospital (0-10 score) between groups (assumption P=.05, power 90%). Given limited information on primary outcome, an a priori plan was in place to conduct the study for 2 months. One hundred fifty-two women were randomized (n=76 early rounding; n=76 delayed rounding). More women had a cesarean delivery in the early compared with the delayed rounding group (47.4% compared with 22.4%). Median rating of the hospital was higher in the delayed as compared with the early rounding group (9.0 [7.0-9.0] compared with 7.0 [6.0-8.0]; P<.01). Median scores regarding physician communication and perception of hospital experiences were higher in the delayed compared with the early group (8.0 [7.0-9.0] compared with 6.0 [5.0-7.0]; P<.001). Adjustment for delivery mode did not alter results (P<.01). No differences in timing of maternal (P=.47) or neonatal hospital discharge (P=.35) were observed. Postpartum women receiving delayed physician rounding were more satisfied with their hospital experience and patient-physician communication without prolonging maternal or neonatal discharge. ClinicalTrials.gov, https://clinicaltrials.gov, NCT02432573.

Does Reviewing Lead to Better Learning and Decision Making? Answers from a Randomized Stock Market Experiment

PubMed Central

Wessa, Patrick; Holliday, Ian E.

2012-01-01

Background The literature is not univocal about the effects of Peer Review (PR) within the context of constructivist learning. Due to the predominant focus on using PR as an assessment tool, rather than a constructivist learning activity, and because most studies implicitly assume that the benefits of PR are limited to the reviewee, little is known about the effects upon students who are required to review their peers. Much of the theoretical debate in the literature is focused on explaining how and why constructivist learning is beneficial. At the same time these discussions are marked by an underlying presupposition of a causal relationship between reviewing and deep learning. Objectives The purpose of the study is to investigate whether the writing of PR feedback causes students to benefit in terms of: perceived utility about statistics, actual use of statistics, better understanding of statistical concepts and associated methods, changed attitudes towards market risks, and outcomes of decisions that were made. Methods We conducted a randomized experiment, assigning students randomly to receive PR or non–PR treatments and used two cohorts with a different time span. The paper discusses the experimental design and all the software components that we used to support the learning process: Reproducible Computing technology which allows students to reproduce or re–use statistical results from peers, Collaborative PR, and an AI–enhanced Stock Market Engine. Results The results establish that the writing of PR feedback messages causes students to experience benefits in terms of Behavior, Non–Rote Learning, and Attitudes, provided the sequence of PR activities are maintained for a period that is sufficiently long. PMID:22666385

Verbal Bullying Changes Among Students Following an Educational Intervention Using the Integrated Model for Behavior Change.

PubMed

Naidoo, Saloshni; Satorius, Benn K; de Vries, Hein; Taylor, Myra

2016-11-01

Bullying behavior in schools can lead to psychosocial problems. School-based interventions are important in raising student awareness, developing their skills and in planning to reduce bullying behavior. A randomized controlled trial, using a school-based educational intervention to reduce verbal bullying, was conducted among grade 10 students in 16 urban and rural schools in KwaZulu-Natal, South Africa in 2013. Baseline and postintervention questionnaires, developed using the Integrated Model for Behavior Change theoretical model, were used to assess changes in verbal bullying. Postintervention there were reduced verbal bullying experiences. Improved social norms and awareness of verbal bullying were associated with reduced verbal bullying experiences and behavior. Although less likely to bully others verbally, girls were more likely to experience verbal bullying. Students with no living father were more likely to bully others verbally. The study findings indicate that a school-based intervention can positively impact on verbal bullying experiences and behavior. © 2016, American School Health Association.

The effect of drawing on children's experiences of investigations following alleged child abuse.

PubMed

Katz, Carmit; Barnetz, Zion; Hershkowitz, Irit

2014-05-01

The primary aim of the study was to evaluate investigative interviews from the perspectives of the children, comparing children who drew with children who did not. One hundred twenty-five children, alleged victims of sexual abuse, were asked about their investigative experience. The uniqueness of the study is that all of the interviews were conducted according to the NICHD Protocol and that children were randomly assigned into one of the two research conditions (drawing vs. non-drawing). The results clearly demonstrate the advantage that drawing has on the children's experience of the investigation, with children in the drawing group more often reporting feelings of hope and success. This study provides practical guidelines for practitioners by emphasizing the beneficial effects that drawing can have. The study stresses the importance of integrating into forensic investigations interventions that enhance children's testimonies and ensure that the investigation is an empowering experience that generates feelings of trust, self-worth, and justice. Copyright © 2014 Elsevier Ltd. All rights reserved.

Divalproex Sodium for the Treatment of PTSD and Conduct Disordered Youth: A Pilot Randomized Controlled Clinical Trial

ERIC Educational Resources Information Center

Steiner, Hans; Saxena, Kirti S.; Carrion, Victor; Khanzode, Leena A.; Silverman, Melissa; Chang, Kiki

2007-01-01

We examined the efficacy of divalproex sodium (DVP) for the treatment of PTSD in conduct disorder, utilizing a previous study in which 71 youth were enrolled in a randomized controlled clinical trial. Twelve had PTSD. Subjects (all males, mean age 16, SD 1.0) were randomized into high and low dose conditions. Clinical Global Impression (CGI)…

A stop-restart solid propellant study with salt quench

NASA Technical Reports Server (NTRS)

Kumar, R. N.

1976-01-01

Experiments were conducted to gain insight into the unsatisfactory performance of the salt quench system of solid propellants in earlier studies. Nine open-air salt spray tests were conducted and high-speed cinematographic coverage was obtained of the events. It is shown that the salt spray by the detonator is generally a two-step process yielding two different fractions. The first fraction consists of finely powdered salt and moves practically unidirectionally at a high velocity (thousand of feet per second) while the second fraction consists of coarse particles and moves randomly at a low velocity (a few feet per second). Further investigation is required to verify the speculation that a lower quench charge ratio (weight of salt/propellant burning area) than previously employed may lead to an efficient quench

A Randomized Trial of the Impact of Survey Design Characteristics on Response Rates Among Nursing Home Providers

PubMed Central

Clark, Melissa; Rogers, Michelle; Foster, Andrew; Dvorchak, Faye; Saadeh, Frances; Weaver, Jessica; Mor, Vincent

2013-01-01

An experiment was conducted to maximize participation of both the Director of Nursing (DoN) and the Administrator (ADMIN) in long-term care facilities. Providers in each of the 224 randomly selected facilities were randomly assigned to 1 of 16 conditions based on the combination of data collection mode (web vs. mail), questionnaire length (short vs. long), and incentive structure. Incentive structures were determined by amount compensated if the individual completed and an additional amount per individual if the pair completed (a) $30 individual/$5 pair/$35 total; (b) $10 individual/$25 pair/$35 total; (c) $30 individual/$20 pair/$50 total; and (d) $10 individual/$40 pair/$50 total. Overall, 47.4% of eligible respondents participated; both respondents participated in 29.3% of facilities. In multivariable analyses, there were no differences in the likelihood of both respondents participating by mode, questionnaire length, or incentive structure. Providing incentives contingent on participation by both providers of a facility was an ineffective strategy for significantly increasing response rates. PMID:21411474

The use of telephone in genetic counseling versus in-person counseling: a randomized study on counselees' outcome.

PubMed

Platten, Ulla; Rantala, Johanna; Lindblom, Annika; Brandberg, Yvonne; Lindgren, Gunilla; Arver, Brita

2012-09-01

Increased demand for genetic counseling services necessitates exploring alternatives to in-person counseling. Telephone counseling is a less time-consuming and more cost-effective alternative. So far there is insufficient evidence to support a pre-counseling telephone model. This randomized questionnaire study aims to evaluate the oncogenetic counseling process and to compare the impact of the initial part of the oncogenetic counseling, when conducted via telephone versus in-person. The aspects of evaluations were: patients' expectations, satisfaction and experiences of genetic counseling, worry for developing hereditary cancer and health related quality of life. A total of 215 participants representing several cancer syndromes were randomized to counseling via telephone or in-person. The questionnaires were completed before and after oncogenetic nurse counseling, and 1 year after the entire counseling process. Overall, a high satisfaction rate with the oncogenetic counseling process was found among the participants regardless of whether the oncogenetic nurse counseling was conducted by telephone or in-person. The results show that a considerable number of participants experienced difficulties with the process of creating a pedigree and dissatisfaction with information on surveillance and prevention. Affected participants reported lower levels in most SF-36 domains compared to non-affected and both groups reported lower levels as compared to a Swedish reference group. The results indicate that telephone pre-counseling works as well as in-person counseling. Emotional support during genetic counseling and information on recommended cancer prevention and surveillance should be improved.

Reliability of Space-Shuttle Pressure Vessels with Random Batch Effects

NASA Technical Reports Server (NTRS)

Feiveson, Alan H.; Kulkarni, Pandurang M.

2000-01-01

In this article we revisit the problem of estimating the joint reliability against failure by stress rupture of a group of fiber-wrapped pressure vessels used on Space-Shuttle missions. The available test data were obtained from an experiment conducted at the U.S. Department of Energy Lawrence Livermore Laboratory (LLL) in which scaled-down vessels were subjected to life testing at four accelerated levels of pressure. We estimate the reliability assuming that both the Shuttle and LLL vessels were chosen at random in a two-stage process from an infinite population with spools of fiber as the primary sampling unit. Two main objectives of this work are: (1) to obtain practical estimates of reliability taking into account random spool effects and (2) to obtain a realistic assessment of estimation accuracy under the random model. Here, reliability is calculated in terms of a 'system' of 22 fiber-wrapped pressure vessels, taking into account typical pressures and exposure times experienced by Shuttle vessels. Comparisons are made with previous studies. The main conclusion of this study is that, although point estimates of reliability are still in the 'comfort zone,' it is advisable to plan for replacement of the pressure vessels well before the expected Lifetime of 100 missions per Shuttle Orbiter. Under a random-spool model, there is simply not enough information in the LLL data to provide reasonable assurance that such replacement would not be necessary.

Effect of theory-based intervention to promote physical activity among adolescent girls: a randomized control trial

PubMed Central

Darabi, Fatemeh; Kaveh, Mohammad Hossein; Majlessi, Fereshteh; Farahani, Farideh Khalaj Abadi; Yaseri, Mehdi; Shojaeizadeh, Davoud

2017-01-01

Background Physical activity (PA) rates decline among most high school female students, and due to cultural restrictions, the reduction of physical activity might be exacerbated in female Iranian adolescents. Objective To determine the effects of the physical activity education theory-based intervention to promote activity among adolescent girls. Methods This randomized clinical trial was conducted at public high schools in Tehran, Iran, from September 2015 to July 2016 on 578 girls. The subjects were assigned randomly to two groups of experiment and control (n=289 per group). All participants in the experimental group received an educational program based on a modified TPB. Measures were assessed before and 6 months after the experiment. The data were analyzed using SPSS version 23. We used descriptive statistics, multilevel analysis, Likelihood Ratio (LR) test, P-value less than 0.05 were considered statistically significant. Results Five hundred and seventy-eight participants with a mean age of 14.26±0.96 years were studied in two groups of experiment (n=289) and control (n=289). Moreover, adjusted for the baseline values, the mean of the scores of the knowledge (84.1±13.6), attitude (31.2±13.6), subjective norm (40.4±11.1), behavioral intention (34.3±14.7), perceived behavioral control (38.4±11.6), perceived parental control (42.9±14.2), behavioral (42.6±17.1) was significantly higher in the experiment group compared with the control group (p<0.001). Conclusions The results of this study implicate that theory based educational intervention is considered to be more effective in improving physical activity in adolescents. This result can be used to increase adolescent’s health promotion. Trial registration The trial was registered at the Iranian Registry of Clinical Trials (IRST) with the identification number: IRCT2015070623089N2. Funding The authors received no financial support for the research from Kermanshah University of Medical Sciences. PMID:28607661

RESILIENCE IN VULNERABLE POPULATIONS WITH TYPE 2 DIABETES MELLITUS AND HYPERTENSION: A SYSTEMATIC REVIEW AND META-ANALYSIS

PubMed Central

Pesantes, M. Amalia; Lazo-Porras, María; Abu Dabrh, Abd Moain; Avila-Ramirez, Jaime R.; Caycho, Maria; Villamonte, Georgina Y.; Sanchez-Perez, Grecia P.; Málaga, Germán; Bernabé-Ortiz, Antonio; Miranda, J. Jaime

2015-01-01

Background Patients with chronic conditions and limited access to healthcare experience stressful challenges due to the burden of managing both their conditions and their daily life demands. Resilience provides a mechanism of adapting to stressful experiences. We conducted a systematic review and meta-analysis to synthesize the evidence about interventions to enhance resiliency in managing hypertension or type-2 diabetes in vulnerable populations, and to assess the efficacy of these interventions on clinical outcomes. Methods We searched multiple databases from early inception through February 2015 including randomized controlled trials that enrolled patients with type-2 diabetes or hypertension. All interventions that targeted resilience in vulnerable populations were included. Data were synthesized to describe the characteristics and efficacy of resilience interventions. We pooled the total effects by calculating standardized mean difference using the random-effects model. Results The final search yielded seventeen studies. All studies were conducted in the United States and generally targeted minority participants. Resiliency interventions used diverse strategies; discussion groups or workshops were the most common approach. Conclusions Interventions aimed at enhancing the resiliency of patients from vulnerable groups are diverse. Outcomes were not fully conclusive. There was some evidence that resilience interventions had a positive effect on HbA1c levels, but not blood pressure. The incorporation of resiliency-oriented interventions into the arsenal of prevention and management of chronic conditions appears to be an opportunity that remains to be better investigated and exploited, and there is need to pursue further understanding of the core components of any intervention that claims to enhance resilience. PMID:26239007

Effect of Continued Support of Midwifery Students in Labour on the Childbirth and Labour Consequences: A Randomized Controlled Clinical Trial

PubMed Central

Bolbol-Haghighi, Nahid; Masoumi, Seyedeh Zahra

2016-01-01

Introduction Childbirth experience is a process throughout women’s life and the most important consequence of labour. Support is the key factor to have a positive experience of childbirth. In order to improve and reduce the stress and anxiety levels in women during labour and cope with the childbirth pain, the emotional, physical and educational support of doulas can be used. Aim This study was aimed to evaluate the effect of continued support of midwifery students in labour on the childbirth and labour consequences. Materials and Methods The present study was conducted using a randomized controlled clinical trial design on 100 pregnant women referred to the maternity ward at Fatemieh Hospital, Shahroud, Iran. The participants were assigned to the supportive or non-supportive group based on allocation sequence using a randomized block design and table of computer-generated random numbers prior to beginning the study. Supportive care was provided by the trained midwifery students. Childbirth and labour consequences were analysed by chi-square test, Fisher-exact test, independent t-test, Mann-Whitney U-test using SPSS-21 software. Results The results showed a significantly lower duration of the first stage of labour in the supportive group, as compared to that in the non-supportive group (p <0.001). Moreover, Apgar scores in the supportive group, compared to those in the non-supportive group, significantly increased at minutes 1 and 5 (p <0.001 and p = 0.04, respectively). Conclusion The findings of this study showed that the supportive care provided by the midwifery students shortens duration of the first stage of labour and improves the Apgar scores in the first and fifth minutes. PMID:27790526

Quality assurance experience with the randomized neuropathic bone pain trial (Trans-Tasman Radiation Oncology Group, 96.05).

PubMed

Roos, Daniel E; Davis, Sidney R; Turner, Sandra L; O'Brien, Peter C; Spry, Nigel A; Burmeister, Bryan H; Hoskin, Peter J; Ball, David L

2003-05-01

Trans-Tasman Radiation Oncology Group 96.05 is a prospective randomized controlled trial comparing a single 8 Gy with 20 Gy in five fractions of radiotherapy (RT) for neuropathic pain due to bone metastases. This paper summarizes the quality assurance (QA) activities for the first 234 patients (accrual target 270). Independent audits to assess compliance with eligibility/exclusion criteria and appropriateness of treatment of the index site were conducted after each cohort of approximately 45 consecutive patients. Reported serious adverse events (SAEs) in the form of cord/cauda equina compression or pathological fracture developing at the index site were investigated and presented in batches to the Independent Data Monitoring Committee. Finally, source data verification of the RT prescription page and treatment records was undertaken for each of the first 234 patients to assess compliance with the protocol. Only one patient was found conclusively not to have genuine neuropathic pain, and there were no detected 'geographical misses' with RT fields. The overall rate of detected infringements for other eligibility criteria over five audits (225 patients) was 8% with a dramatic improvement after the first audit. There has at no stage been a statistically significant difference in SAEs by randomization arm. There was a 22% rate of RT protocol variations involving ten of the 14 contributing centres, although the rate of major dose violations (more than +/-10% from protocol dose) was only 6% with no statistically significant difference by randomization arm (P=0.44). QA auditing is an essential but time-consuming component of RT trials, including those assessing palliative endpoints. Our experience confirms that all aspects should commence soon after study activation.

Social aggregation in pea aphids: experiment and random walk modeling.

PubMed

Nilsen, Christa; Paige, John; Warner, Olivia; Mayhew, Benjamin; Sutley, Ryan; Lam, Matthew; Bernoff, Andrew J; Topaz, Chad M

2013-01-01

From bird flocks to fish schools and ungulate herds to insect swarms, social biological aggregations are found across the natural world. An ongoing challenge in the mathematical modeling of aggregations is to strengthen the connection between models and biological data by quantifying the rules that individuals follow. We model aggregation of the pea aphid, Acyrthosiphon pisum. Specifically, we conduct experiments to track the motion of aphids walking in a featureless circular arena in order to deduce individual-level rules. We observe that each aphid transitions stochastically between a moving and a stationary state. Moving aphids follow a correlated random walk. The probabilities of motion state transitions, as well as the random walk parameters, depend strongly on distance to an aphid's nearest neighbor. For large nearest neighbor distances, when an aphid is essentially isolated, its motion is ballistic with aphids moving faster, turning less, and being less likely to stop. In contrast, for short nearest neighbor distances, aphids move more slowly, turn more, and are more likely to become stationary; this behavior constitutes an aggregation mechanism. From the experimental data, we estimate the state transition probabilities and correlated random walk parameters as a function of nearest neighbor distance. With the individual-level model established, we assess whether it reproduces the macroscopic patterns of movement at the group level. To do so, we consider three distributions, namely distance to nearest neighbor, angle to nearest neighbor, and percentage of population moving at any given time. For each of these three distributions, we compare our experimental data to the output of numerical simulations of our nearest neighbor model, and of a control model in which aphids do not interact socially. Our stochastic, social nearest neighbor model reproduces salient features of the experimental data that are not captured by the control.

Iron and cardiac ischemia: a natural, quasi-random experiment comparing eligible with disqualified blood donors.

PubMed

Germain, Marc; Delage, Gilles; Blais, Claudia; Maunsell, Elizabeth; Décary, Francine; Grégoire, Yves

2013-06-01

The theory that elevated iron stores can induce vascular injury and ischemia remains controversial. We conducted a cohort study of the effect of blood donation on the risk of coronary heart disease (CHD) by taking advantage of the quasi-random exclusion of donors who obtained a falsely reactive test for a transmissible disease (TD) marker. Whole blood donors who were permanently disqualified because of a false-reactive test between 1990 and 2007 in the province of Quebec were compared to donors who remained eligible, matched for baseline characteristics. The incidence of CHD after entry into the study was determined through hospitalization and death records. We compared eligible and disqualified donors using an "intention-to-treat" framework. Overall, 12,357 donors who were permanently disqualified were followed for 124,123 person-years of observation, plus 50,889 donors who remained eligible (516,823 person-years). On average, donors who remained eligible made 0.36 donation/year during follow-up and had an incidence of hospitalizations or deaths attributable to CHD of 3.60/1000 person-years, compared to 3.52 among permanently disqualified donors (rate ratio, 1.02; 95% confidence interval, 0.92-1.13). Donors who remained eligible did not have a lower risk of CHD, compared to donors who were permanently disqualified due to a false-reactive TD marker. Because of the quasi-random nature of false-reactive screening tests, this natural experiment has a level of validity approaching that of a randomized trial evaluating the effect of regular blood donation on CHD risk. These results do not support the iron hypothesis. © 2013 American Association of Blood Banks.

Ethical challenges in cluster randomized controlled trials: experiences from public health interventions in Africa and Asia

PubMed Central

Azad, Kishwar; Fernandez, Armida; Manandhar, Dharma S; Mwansambo, Charles W; Tripathy, Prasanta; Costello, Anthony M

2009-01-01

Abstract Public health interventions usually operate at the level of groups rather than individuals, and cluster randomized controlled trials (RCTs) are one means of evaluating their effectiveness. Using examples from six such trials in Bangladesh, India, Malawi and Nepal, we discuss our experience of the ethical issues that arise in their conduct. We set cluster RCTs in the broader context of public health research, highlighting debates about the need to reconcile individual autonomy with the common good and about the ethics of public health research in low-income settings in general. After a brief introduction to cluster RCTs, we discuss particular challenges we have faced. These include the nature of – and responsibility for – group consent, and the need for consent by individuals within groups to intervention and data collection. We discuss the timing of consent in relation to the implementation of public health strategies, and the problem of securing ethical review and approval in a complex domain. Finally, we consider the debate about benefits to control groups and the standard of care that they should receive, and the issue of post-trial adoption of the intervention under test. PMID:19876544

The effects of race and racial priming on self-report of contamination anxiety

PubMed Central

Williams, Monnica T.; Turkheimer, Eric; Magee, Emily; Guterbock, Thomas

2011-01-01

African Americans show unusually high endorsement rates on self-report measures of contamination anxiety. The purpose of this study was to replicate this finding in a nationally representative sample and conduct a randomized experiment to determine the effect of salience of race as a causal factor. Black and White participants were given contamination items from two popular measures of obsessive-compulsive disorder, half prior to being primed about ethnic identity and half after being primed, via the administration of an ethnic identity measure. The experiment took the form of a 2 (Black and White participant) X 2 (ethnicity salient and ethnicity non-salient) double-blind design, with ethnic saliency assigned at random by computer. Participants consisted of a geographically representative US sample of African Americans supplemented with a similar sample of European Americans (N=258). Black participants scored significantly higher than White participants on contamination scales. Participants from Southern states scored higher than those from other regions. Over-endorsements by Black participants were greater when awareness of ethnic and racial identification was increased. Clinical and research implications were discussed; these measures should be used with caution in African Americans. PMID:22163374

Patients' experiences with navigation for cancer care.

PubMed

Carroll, Jennifer K; Humiston, Sharon G; Meldrum, Sean C; Salamone, Charcy M; Jean-Pierre, Pascal; Epstein, Ronald M; Fiscella, Kevin

2010-08-01

We examined how navigation, defined as the assessment and alleviation of barriers to adequate health care, influences patients' perspectives on the quality of their cancer care. We conducted post-study patient interviews from a randomized controlled trial (usual care vs. patient navigation services) from cancer diagnosis through treatment completion. Patients were recruited from 11 primary care, hospital and community oncology practices in New York. We interviewed patients about their expectations and experience of patient navigation or, for non-navigated patients, other sources of assistance. Thirty-five patients newly diagnosed with breast or colorectal cancer. Valued aspects of navigation included emotional support, assistance with information needs and problem-solving, and logistical coordination of cancer care. Unmet cancer care needs expressed by patients randomized to usual care consisted of lack of assistance or support with childcare, household responsibilities, coordination of care, and emotional support. Cancer patients value navigation. Instrumental benefits were the most important expectations for navigation from navigated and non-navigated patients. Navigated patients received emotional support and assistance with information needs, problem-solving, and logistical aspects of cancer care coordination. Navigation services may help improve cancer care outcomes important to patients by addressing fragmented, confusing, uncoordinated, or inefficient care. Copyright 2009 Elsevier Ireland Ltd. All rights reserved.

An Examination of Strategy Implementation During Abstract Nonlinguistic Category Learning in Aphasia.

PubMed

Vallila-Rohter, Sofia; Kiran, Swathi

2015-08-01

Our purpose was to study strategy use during nonlinguistic category learning in aphasia. Twelve control participants without aphasia and 53 participants with aphasia (PWA) completed a computerized feedback-based category learning task consisting of training and testing phases. Accuracy rates of categorization in testing phases were calculated. To evaluate strategy use, strategy analyses were conducted over training and testing phases. Participant data were compared with model data that simulated complex multi-cue, single feature, and random pattern strategies. Learning success and strategy use were evaluated within the context of standardized cognitive-linguistic assessments. Categorization accuracy was higher among control participants than among PWA. The majority of control participants implemented suboptimal or optimal multi-cue and single-feature strategies by testing phases of the experiment. In contrast, a large subgroup of PWA implemented random patterns, or no strategy, during both training and testing phases of the experiment. Person-to-person variability arises not only in category learning ability but also in the strategies implemented to complete category learning tasks. PWA less frequently developed effective strategies during category learning tasks than control participants. Certain PWA may have impairments of strategy development or feedback processing not captured by language and currently probed cognitive abilities.

Kinesio Taping for pain control during labor: Protocol of a randomized, controlled trial.

PubMed

Miquelutti, Maria Amelia; Cecatti, José Guilherme

2017-03-01

This study protocol will evaluate the effectiveness and safety during labor and delivery of the Kinesio Taping bandage for pain sensation, satisfaction of patients, and obstetric and neonatal outcomes. A randomized controlled trial with 60 participants divided into two groups will be conducted. The intervention group will receive bandage application on the vertebral regions corresponding to uterine dermatomes - from T10 to L1 and from S2 to S4. The control group will receive bandage application away from uterine dermatomes, from T1 to T4. The primary endpoint is pain during labor. Secondary endpoints are perinatal outcomes and patient satisfaction with the bandage and with her labor. Pain levels will be evaluated on an hourly basis during labor, and intention-to-treat analysis will be performed. Risk ratios and 95% confidence intervals will be calculated. Findings on effectiveness of pain control with no adverse effects to both the mother and neonate are the first step in evaluating the systematic use of Kinesio Taping during labor. Since self-control may affect birthing experience satisfaction, discovering new alternatives for pain control may allow for a better experience. © 2017 John Wiley & Sons Australia, Ltd.

Patients' Experiences with Navigation for Cancer Care

PubMed Central

Carroll, Jennifer K.; Humiston, Sharon G.; Meldrum, Sean C.; Salamone, Charcy M.; Jean-Pierre, Pascal; Epstein, Ronald M.; Fiscella, Kevin

2010-01-01

Objective We examined how navigation, defined as the assessment and alleviation of barriers to adequate health care, influences patients' perspectives on the quality of their cancer care. Methods We conducted post-study patient interviews from a randomized controlled trial (usual care vs. patient navigation services) from cancer diagnosis through treatment completion. Patients were recruited from 11 primary care, hospital and community oncology practices in New York. We interviewed patients about their expectations and experience of patient navigation or, for non-navigated patients, other sources of assistance. Results Thirty-five patients newly diagnosed with breast or colorectal cancer. Valued aspects of navigation included emotional support, assistance with information needs and problem-solving, and logistical coordination of cancer care. Unmet cancer care needs expressed by patients randomized to usual care consisted of lack of assistance or support with childcare, household responsibilities, coordination of care, and emotional support. Conclusion Cancer patients value navigation. Instrumental benefits were the most important expectations for navigation from navigated and non-navigated patients. Navigated patients received emotional support and assistance with information needs, problem-solving, and logistical aspects of cancer care coordination. Practice Implications Navigation services may help improve cancer care outcomes important to patients by addressing fragmented, confusing, uncoordinated, or inefficient care. PMID:20006459

Align and random electrospun mat of PEDOT:PSS and PEDOT:PSS/RGO

NASA Astrophysics Data System (ADS)

Sarabi, Ghazale Asghari; Latifi, Masoud; Bagherzadeh, Roohollah

2018-01-01

In this research work we fabricated two ultrafine conductive nanofibrous layers to investigate the materilas composition and their properties for the preparation of supercapacitor materials application. In first layer, a polymer and a conductive polymer were used and second layer was a composition of polymer, conductive polymer and carbon-base material. In both cases align and randomized mat of conductive nanofibers were fabricated using electrospinning set up. Conductive poly (3,4-ethylenedioxythiophene)/ polystyrene sulfonate (PEDOT:PSS) nanofibers were electrospun by dissolving fiber-forming polymer and polyvinyl alcohol (PVA) in an aqueous dispersion of PEDOT:PSS. The effect of addition of reduced graphene oxide (RGO) was considered for nanocomposite layer. The ultrafine conductive polymer fibers and conductive nanocomposite fibrous materials were also fabricated using an electrospinning process. A fixed collector and a rotating drum were used for random and align nanofibers production, respectively. The resulted fibers were characterized and analyzed by SEM, FTIR and two-point probe conductivity test. The average diameter of nanofibers measured by ImageJ software indicated that the average fiber diameter for first layer was 100 nm and for nanocomposite layer was about 85 nm. The presence of PEDOT:PSS and RGO in the nanofibers was confirmed by FT-IR spectroscopy. The conductivity of align and random layers was characterized. The conductivity of PEDOT:PSS nanofibers showed higher enhancement by addition of RGO in aqueous dispersion. The obtained results showed that alignment of fibrous materials can be considered as an engineering tool for tuning the conductivity of fibrous materials for many different applications such as supercapacitors, conductive and transparent materials.

People's Intuitions about Randomness and Probability: An Empirical Study

ERIC Educational Resources Information Center

Lecoutre, Marie-Paule; Rovira, Katia; Lecoutre, Bruno; Poitevineau, Jacques

2006-01-01

What people mean by randomness should be taken into account when teaching statistical inference. This experiment explored subjective beliefs about randomness and probability through two successive tasks. Subjects were asked to categorize 16 familiar items: 8 real items from everyday life experiences, and 8 stochastic items involving a repeatable…

Establishing Sprinkling Requirements on Trailers Transporting Market Weight Pigs in Warm and Hot Weather.

PubMed

Kephart, Rebecca; Johnson, Anna; Sapkota, Avi; Stalder, Kenneth; McGlone, John

2014-04-11

This study was conducted July of 2012 in Iowa, in WARM (<26.7 °C) and HOT (≥26.7 °C) weather. Four sprinkling methods were compared, with one treatment being randomly assigned to each load: control- no sprinkling (not applied in HOT weather), pigs only, bedding only, or pigs and bedding. Experiment 1 used 51 loads in WARM- and 86 loads in HOT weather to determine sprinkling effects on pig measures (surface temperature, vocalizations, slips and falls, and stress signs). Experiment 2 used 82 loads in WARM- and 54 loads in HOT weather to determine the sprinkling effects on transport losses (non-ambulatory, dead, and total transport losses). Experiment 1 found that, in WARM weather, there were no differences between sprinkling treatments for surface temperature, vocalizations, or slips and falls (p ≥ 0.18). However, stress signs were 2% greater when sprinkling pigs- or bedding only- compared to control (p = 0.03). Experiment 2 found that, in WARM and HOT weather, sprinkling did not affect non-ambulatory, dead, or total transport losses (p ≥ 0.18). Although the current study did not find any observed sprinkling effects for pig measures or transport losses it is extremely important to note that the inference space of this study is relatively small, so further studies should be conducted to see if these results are applicable to other geographical regions and seasons.

Characteristics and fall experiences of older adults with and without fear of falling outdoors.

PubMed

Chippendale, Tracy; Lee, Chang Dae

2018-06-01

Using a theoretical model that combines an ecological perspective and Bandura's theory of self-efficacy as a guide, we sought to compare experiences and characteristics of community dwelling older adults with and without concern about falling outdoors. A survey of randomly selected community dwelling older adults across NYC (N = 120) was conducted using the outdoor falls questionnaire. Descriptive quantitative analyses of participant characteristics were conducted for all participants and for those with and without concern about falling outside. Conventional content analysis using two coders was employed to examine outdoor fall experiences for each group. A mixed methods matrix was used to integrate qualitative and quantitative findings. Some participant characteristics were more common among those with a concern about falling outside such as decreased functional status, female gender, and number of prior outdoor falls. As per descriptions of outdoor fall experiences, participants with concern were more likely to report a fall while climbing stairs or stepping up a curb, describe an intrinsic factor as a cause of their fall, use an injury prevention strategy during the fall, sustain a moderate to severe injury, seek medical attention, have had an ambulance called, require help to get up, and describe implementation of a behavioral change after the fall. Differences exist in participant characteristics and outdoor fall experiences of those with and without concern about falling outside. The proposed model can be used to understand fear of falling outdoors and can help to inform the target population and content of intervention programs.

TRANSFER OF AVERSIVE RESPONDENT ELICITATION IN ACCORDANCE WITH EQUIVALENCE RELATIONS

PubMed Central

Valverde, Miguel RodrÍguez; Luciano, Carmen; Barnes-Holmes, Dermot

2009-01-01

The present study investigates the transfer of aversively conditioned respondent elicitation through equivalence classes, using skin conductance as the measure of conditioning. The first experiment is an attempt to replicate Experiment 1 in Dougher, Augustson, Markham, Greenway, and Wulfert (1994), with different temporal parameters in the aversive conditioning procedure employed. Match-to-sample procedures were used to teach 17 participants two 4-member equivalence classes. Then, one member of one class was paired with electric shock and one member of the other class was presented without shock. The remaining stimuli from each class were presented in transfer tests. Unlike the findings in the original study, transfer of conditioning was not achieved. In Experiment 2, similar procedures were used with 30 participants, although several modifications were introduced (formation of five-member classes, direct conditioning with several elements of each class, random sequences of stimulus presentation in transfer tests, reversal in aversive conditioning contingencies). More than 80% of participants who had shown differential conditioning also showed the transfer of function effect. Moreover, this effect was replicated within subjects for 3 participants. This is the first demonstration of the transfer of aversive respondent elicitation through stimulus equivalence classes with the presentation of transfer test trials in random order. The latter prevents the possibility that transfer effects are an artefact of transfer test presentation order. PMID:20119523

Realization of the Switching Mechanism in Resistance Random Access Memory™ Devices: Structural and Electronic Properties Affecting Electron Conductivity in a Hafnium Oxide-Electrode System Through First-Principles Calculations

NASA Astrophysics Data System (ADS)

Aspera, Susan Meñez; Kasai, Hideaki; Kishi, Hirofumi; Awaya, Nobuyoshi; Ohnishi, Shigeo; Tamai, Yukio

2013-01-01

The resistance random access memory (RRAM™) device, with its electrically induced nanoscale resistive switching capacity, has attracted considerable attention as a future nonvolatile memory device. Here, we propose a mechanism of switching based on an oxygen vacancy migration-driven change in the electronic properties of the transition-metal oxide film stimulated by set pulse voltages. We used density functional theory-based calculations to account for the effect of oxygen vacancies and their migration on the electronic properties of HfO2 and Ta/HfO2 systems, thereby providing a complete explanation of the RRAM™ switching mechanism. Furthermore, computational results on the activation energy barrier for oxygen vacancy migration were found to be consistent with the set and reset pulse voltage obtained from experiments. Understanding this mechanism will be beneficial to effectively realizing the materials design in these devices.

A Systematic Review of Randomized Controlled Trials of Interventions to Improve the Health of Persons During Imprisonment and in the Year After Release

PubMed Central

McIsaac, Kathryn E.; Liauw, Jessica; Green, Samantha; Karachiwalla, Fareen; Siu, Winnie; Burkholder, Kaite; Binswanger, Ingrid; Kiefer, Lori; Kinner, Stuart A.; Korchinski, Mo; Matheson, Flora I.; Young, Pam; Hwang, Stephen W.

2015-01-01

We systematically reviewed randomized controlled trials of interventions to improve the health of people during imprisonment or in the year after release. We searched 14 biomedical and social science databases in 2014, and identified 95 studies. Most studies involved only men or a majority of men (70/83 studies in which gender was specified); only 16 studies focused on adolescents. Most studies were conducted in the United States (n = 57). The risk of bias for outcomes in almost all studies was unclear or high (n = 91). In 59 studies, interventions led to improved mental health, substance use, infectious diseases, or health service utilization outcomes; in 42 of these studies, outcomes were measured in the community after release. Improving the health of people who experience imprisonment requires knowledge generation and knowledge translation, including implementation of effective interventions. PMID:25713970

Impact of Attention Training on Academic Achievement, Executive Functioning, and Behavior: A Randomized Controlled Trial.

PubMed

Kirk, Hannah; Gray, Kylie; Ellis, Kirsten; Taffe, John; Cornish, Kim

2017-03-01

Children with intellectual and developmental disabilities (IDD) experience significant difficulties in attention, learning, executive functions, and behavioral regulation. Emerging evidence suggests that computerized cognitive training may remediate these impairments. In a double blind controlled trial, 76 children with IDD (4-11 years) were randomized to either an attention training (n = 38) or control program (n = 38). Both programs were completed at home over a 5-week period. Outcome measures assessed literacy, numeracy, executive functioning, and behavioral/emotional problems, and were conducted at baseline, post-training, and 3-month follow-up. No training effects were observed at post-training; however, children in the training group showed greater improvements in numeracy skills at the 3-month follow-up. These results suggest that attention training may be beneficial for children with IDD; however, the modest nature of the intervention effects indicate that caution should be taken when interpreting clinical significance.

Efficiency improvement by navigated safety inspection involving visual clutter based on the random search model.

PubMed

Sun, Xinlu; Chong, Heap-Yih; Liao, Pin-Chao

2018-06-25

Navigated inspection seeks to improve hazard identification (HI) accuracy. With tight inspection schedule, HI also requires efficiency. However, lacking quantification of HI efficiency, navigated inspection strategies cannot be comprehensively assessed. This work aims to determine inspection efficiency in navigated safety inspection, controlling for the HI accuracy. Based on a cognitive method of the random search model (RSM), an experiment was conducted to observe the HI efficiency in navigation, for a variety of visual clutter (VC) scenarios, while using eye-tracking devices to record the search process and analyze the search performance. The results show that the RSM is an appropriate instrument, and VC serves as a hazard classifier for navigation inspection in improving inspection efficiency. This suggests a new and effective solution for addressing the low accuracy and efficiency of manual inspection through navigated inspection involving VC and the RSM. It also provides insights into the inspectors' safety inspection ability.

Reducing Conduct Problems among Children Exposed to Intimate Partner Violence: A Randomized Clinical Trial Examining Effects of Project Support

ERIC Educational Resources Information Center

Jouriles, Ernest N.; McDonald, Renee; Rosenfield, David; Stephens, Nanette; Corbitt-Shindler, Deborah; Miller, Pamela C.

2009-01-01

This study was a randomized clinical trial of Project Support, an intervention designed to reduce conduct problems among children exposed to intimate partner violence. Participants were 66 families (mothers and children) with at least 1 child exhibiting clinical levels of conduct problems. Families were recruited from domestic violence shelters.…

A cluster randomized controlled trial to assess the impact on intimate partner violence of a 10-session participatory gender training curriculum delivered to women taking part in a group-based microfinance loan scheme in Tanzania (MAISHA CRT01): study protocol.

PubMed

Harvey, Sheila; Lees, Shelley; Mshana, Gerry; Pilger, Daniel; Hansen, Christian; Kapiga, Saidi; Watts, Charlotte

2018-04-02

Worldwide, almost one third (30%) of women who have been in a relationship have experienced physical and/or sexual violence from an intimate partner. Given the considerable negative impacts of intimate partner violence (IPV) on women's physical health and well-being, there is an urgent need for rigorous evidence on violence prevention interventions. The study, comprising a cluster randomized controlled trial (RCT) and in-depth qualitative study, will assess the impact on women's past year experience of physical and/or sexual IPV of a participatory gender training curriculum (MAISHA curriculum) delivered to women participating in group-based microfinance in Tanzania. More broadly, the study aims to learn more about the factors that contribute to women's vulnerability to violence and understand how the intervention impacts on the lives of women and their families. Sixty-six eligible microfinance loan groups are enrolled and randomly allocated to: the 10-session MAISHA curriculum, delivered over 20 weeks (n = 33); or, to no intervention (n = 33). Study participants are interviewed at baseline and at 24 months post-intervention about their: household; partner; income; health; attitudes and social norms; relationship (including experiences of different forms of violence); childhood; and community. For the qualitative study and process evaluation, focus group discussions are being conducted with study participants and MAISHA curriculum facilitators. In-depth interviews are being conducted with a purposive sample of 18 participants. The primary outcome, assessed at 24 months post-intervention, is a composite of women's reported experience of physical and/or sexual IPV during the past 12 months. Secondary outcomes include: reported experience of physical, sexual and emotional/psychological IPV during the past 12 months, attitudes towards IPV and reported disclosure of IPV to others. The study forms part of a wider programme of research (MAISHA) that includes: a complementary cluster RCT evaluating the impact of delivering the MAISHA curriculum to women not receiving formal group-based microfinance; an economic evaluation; and a cross-sectional survey of men to explore male risk factors associated with IPV. MAISHA will generate rigorous evidence on violence prevention interventions, as well as further insights into the different forms and consequences of violence and drivers of violence perpetration. ClinicalTrials.gov ID: NCT02592252 , registered retrospectively on 13 August 2015.

When Is It Possible to Conduct a Randomized Controlled Trial in Education at Reduced Cost, Using Existing Data Sources? A Brief Overview

ERIC Educational Resources Information Center

Coalition for Evidence-Based Policy, 2007

2007-01-01

The purpose of this Guide is to advise researchers, policymakers, and others on when it is possible to conduct a high-quality randomized controlled trial in education at reduced cost. Well-designed randomized controlled trials are recognized as the gold standard for evaluating the effectiveness of an intervention (i.e., program or practice) in…

Tunneling Conductivity and Piezoresistivity of Composites Containing Randomly Dispersed Conductive Nano-Platelets

PubMed Central

Oskouyi, Amirhossein Biabangard; Sundararaj, Uttandaraman; Mertiny, Pierre

2014-01-01

In this study, a three-dimensional continuum percolation model was developed based on a Monte Carlo simulation approach to investigate the percolation behavior of an electrically insulating matrix reinforced with conductive nano-platelet fillers. The conductivity behavior of composites rendered conductive by randomly dispersed conductive platelets was modeled by developing a three-dimensional finite element resistor network. Parameters related to the percolation threshold and a power-low describing the conductivity behavior were determined. The piezoresistivity behavior of conductive composites was studied employing a reoriented resistor network emulating a conductive composite subjected to mechanical strain. The effects of the governing parameters, i.e., electron tunneling distance, conductive particle aspect ratio and size effects on conductivity behavior were examined. PMID:28788580

Computer Modeling of Electrostatic Aggregation of Granular Materials in Planetary and Astrophysical Settings

NASA Technical Reports Server (NTRS)

Marshall, J.; Sauke, T.

1999-01-01

Electrostatic forces strongly influence the behavior of granular materials in both dispersed (cloud) systems and semi-packed systems. These forces can cause aggregation or dispersion of particles and are important in a variety of astrophysical and planetary settings. There are also many industrial and commercial settings where granular matter and electrostatics become partners for both good and bad. This partnership is important for human exploration on Mars where dust adheres to suits, machines, and habitats. Long-range Coulombic (electrostatic) forces, as opposed to contact-induced dipoles and van der Waals attractions, are generally regarded as resulting from net charge. We have proposed that in addition to net charge interactions, randomly distributed charge carriers on grains will result in a dipole moment regardless of any net charge. If grains are unconfined, or fluidized, they will rotate so that the dipole always induces attraction between grains. Aggregates are readily formed, and Coulombic polarity resulting from the dipole produces end-to-end stacking of grains to form filamentary aggregates. This has been demonstrated in USML experiments on Space Shuttle where microgravity facilitated the unmasking of static forces. It has also been demonstrated in a computer model using grains with charge carriers of both sign. Model results very closely resembled micro-g results with actual sand grains. Further computer modeling of the aggregation process has been conducted to improve our understanding of the aggregation process, and to provide a predictive tool for microgravity experiments slated for Space Station. These experiments will attempt to prove the dipole concept as outlined above. We have considerably enhanced the original computer model: refinements to the algorithm have improved the fidelity of grain behavior during grain contact, special attention has been paid to simulation time steps to enable establishment of a meaningful, quantitative time axis, and calibration of rounding accuracies have been conducted to test cumulative numerical influences in the model. The model has been run for larger grain populations, variable initial cloud densities, and we have introduced random net charging to individual grains, as well as a net charge to the cloud as a whole. The model uses 3 positive and 3 negative charges randomly distributed on each grain, with up to 160 grains contained within various size "boxes" that define the initial number densities in the clouds. Each charge represents localized charged region on a grain, but does not necessarily imply single quantized charge carriers. The Coulomb equations are then allowed to interact for each monopole: dipoles and any higher order charge coupling is a natural product of these "free" interactions over which the modeler exerts no influence. The charges are placed on surfaces of grains at random locations. A series of runs was conducted for neutral grains that had a perfect balance of negative and positive char carriers. Runs were also conducted with grains having additional fractional charges ranging between 0 and 1. By adding fractional charges of one sign, the model created grain populations in which all grains had excess charges the same sign, giving the cloud an overall net charge. This simulates clouds subjected to ionizing radiation (e. protoplanetary debris disk around a protosun), or any other process of charge biasing in a grain population (e.g., volcanic plumes). In another run series, random fractional charges of either sign were added to the grains so th some grains had a slight net positive charge while others had a slight net negative charge. This simulates triboelectrically-charged grain populations in which acquisition of an electron by one surface is at the expense creating a hole elsewhere. This dual sign charging was applied in two ways: in one case the cloud remained neutral by ensuring that all grain excess charges added to zero; in the other case, the cloud was permitted slight net char by not imposing a charge-balance condition. Additional information is contained in the original.

Incentive and Reminder Strategies to Improve Response Rate for Internet-Based Physician Surveys: A Randomized Experiment

PubMed Central

Wittich, Christopher M; Daniels, Wendlyn L; West, Colin P; Harris, Ann M; Beebe, Timothy J

2016-01-01

Background Most research on how to enhance response rates in physician surveys has been done using paper surveys. Uncertainties remain regarding how to enhance response rates in Internet-based surveys. Objective To evaluate the impact of a low-cost nonmonetary incentive and paper mail reminders (formal letter and postcard) on response rates in Internet-based physician surveys. Methods We executed a factorial-design randomized experiment while conducting a nationally representative Internet-based physician survey. We invited 3966 physicians (randomly selected from a commercial database of all licensed US physicians) via email to complete an Internet-based survey. We used 2 randomly assigned email messages: one message offered a book upon survey completion, whereas the other did not mention the book but was otherwise identical. All nonrespondents received several email reminders. Some physicians were further assigned at random to receive 1 reminder via paper mail (either a postcard or a letter) or no paper reminder. The primary outcome of this study was the survey response rate. Results Of the 3966 physicians who were invited, 451 (11.4%) responded to at least one survey question and 336 (8.5%) completed the entire survey. Of those who were offered a book, 345/2973 (11.6%) responded compared with 106/993 (10.7%) who were not offered a book (odds ratio 1.10, 95% CI 0.87-1.38, P=.42). Regarding the paper mail reminder, 168/1572 (10.7%) letter recipients, 148/1561 (9.5%) postcard recipients, and 69/767 (9.0%) email-only recipients responded (P=.35). The response rate for those receiving letters or postcards was similar (odds ratio 1.14, 95% CI 0.91-1.44, P=.26). Conclusions Offering a modest nonmonetary incentive and sending a paper reminder did not improve survey response rate. Further research on how to enhance response rates in Internet-based physician surveys is needed. PMID:27637296

Incentive and Reminder Strategies to Improve Response Rate for Internet-Based Physician Surveys: A Randomized Experiment.

PubMed

Cook, David A; Wittich, Christopher M; Daniels, Wendlyn L; West, Colin P; Harris, Ann M; Beebe, Timothy J

2016-09-16

Most research on how to enhance response rates in physician surveys has been done using paper surveys. Uncertainties remain regarding how to enhance response rates in Internet-based surveys. To evaluate the impact of a low-cost nonmonetary incentive and paper mail reminders (formal letter and postcard) on response rates in Internet-based physician surveys. We executed a factorial-design randomized experiment while conducting a nationally representative Internet-based physician survey. We invited 3966 physicians (randomly selected from a commercial database of all licensed US physicians) via email to complete an Internet-based survey. We used 2 randomly assigned email messages: one message offered a book upon survey completion, whereas the other did not mention the book but was otherwise identical. All nonrespondents received several email reminders. Some physicians were further assigned at random to receive 1 reminder via paper mail (either a postcard or a letter) or no paper reminder. The primary outcome of this study was the survey response rate. Of the 3966 physicians who were invited, 451 (11.4%) responded to at least one survey question and 336 (8.5%) completed the entire survey. Of those who were offered a book, 345/2973 (11.6%) responded compared with 106/993 (10.7%) who were not offered a book (odds ratio 1.10, 95% CI 0.87-1.38, P=.42). Regarding the paper mail reminder, 168/1572 (10.7%) letter recipients, 148/1561 (9.5%) postcard recipients, and 69/767 (9.0%) email-only recipients responded (P=.35). The response rate for those receiving letters or postcards was similar (odds ratio 1.14, 95% CI 0.91-1.44, P=.26). Offering a modest nonmonetary incentive and sending a paper reminder did not improve survey response rate. Further research on how to enhance response rates in Internet-based physician surveys is needed.

Balancing a U-Shaped Assembly Line by Applying Nested Partitions Method

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

Bhagwat, Nikhil V.

2005-01-01

In this study, we applied the Nested Partitions method to a U-line balancing problem and conducted experiments to evaluate the application. From the results, it is quite evident that the Nested Partitions method provided near optimal solutions (optimal in some cases). Besides, the execution time is quite short as compared to the Branch and Bound algorithm. However, for larger data sets, the algorithm took significantly longer times for execution. One of the reasons could be the way in which the random samples are generated. In the present study, a random sample is a solution in itself which requires assignment ofmore » tasks to various stations. The time taken to assign tasks to stations is directly proportional to the number of tasks. Thus, if the number of tasks increases, the time taken to generate random samples for the different regions also increases. The performance index for the Nested Partitions method in the present study was the number of stations in the random solutions (samples) generated. The total idle time for the samples can be used as another performance index. ULINO method is known to have used a combination of bounds to come up with good solutions. This approach of combining different performance indices can be used to evaluate the random samples and obtain even better solutions. Here, we used deterministic time values for the tasks. In industries where majority of tasks are performed manually, the stochastic version of the problem could be of vital importance. Experimenting with different objective functions (No. of stations was used in this study) could be of some significance to some industries where in the cost associated with creation of a new station is not the same. For such industries, the results obtained by using the present approach will not be of much value. Labor costs, task incompletion costs or a combination of those can be effectively used as alternate objective functions.« less

Openness to experience, work experience and patient safety.

PubMed

Chang, Hao-Yuan; Friesner, Daniel; Lee, I-Chen; Chu, Tsung-Lan; Chen, Hui-Ling; Wu, Wan-Er; Teng, Ching-I

2016-11-01

The purpose of this study is to examine how the interaction between nurse openness and work experience is related to patient safety. No study has yet examined the interactions between these, and how openness and work experience jointly impact patient safety. This study adopts a cross-sectional design, using self-reported work experience, perceived time pressure and measures of patient safety, and was conducted in a major medical centre. The sample consisted of 421 full-time nurses from all available units in the centre. Proportionate random sampling was used. Patient safety was measured using the self-reported frequency of common adverse events. Openness was self-rated using items identified in the relevant literature. Nurse openness is positively related to the patient safety construct (B = 0.08, P = 0.03). Moreover, work experience reduces the relation between openness and patient safety (B = -0.12, P < 0.01). The relationship between openness, work experience and patient safety suggests a new means of improving patient care in a health system setting. Nurse managers may enhance patient safety by assessing nurse openness and assigning highly open nurses to duties that make maximum use of that trait. © 2016 John Wiley & Sons Ltd.

A Randomized Controlled Trial of Bibliotherapy for Carers of Young People With First-Episode Psychosis

PubMed Central

McCann, Terence V.

2013-01-01

Caring for young people with first-episode psychosis (FEP) is challenging and can adversely affect carer well-being, with limited evidence-based support materials available. We aimed to examine whether completion of a self-directed problem-solving bibliotherapy among carers of young people with FEP led to a better experience of caring, less distress and expressed emotion, and better general health than carers who only received treatment as usual (TAU). A randomized controlled trial was conducted across two early-intervention psychosis services in Melbourne, Australia. A total of 124 carers were randomized to problem-solving bibliotherapy intervention (PSBI) or TAU and assessed at baseline, 6-week and 16-week follow-up. Intent-to-treat analyses were carried out and indicated that recipients of PSBI had a more favorable experience of caring than those receiving TAU, and these effects were sustained at both follow-up time points. Across the other measures, both groups demonstrated improvements by week 16, although the PBSI group tended to improve earlier. The PSBI group experienced a greater reduction in negative emotional evaluations of the need to provide additional support to young people with FEP than the TAU group by week 6, while the level of psychological distress decreased at a greater rate from baseline to 6 weeks in the PSBI compared with the TAU group. These findings support the use of problem-solving bibliotherapy for first-time carers, particularly as a cost-effective adjunct to TAU. PMID:23172001

The effect of cannabis on tremor in patients with multiple sclerosis.

PubMed

Fox, P; Bain, P G; Glickman, S; Carroll, C; Zajicek, J

2004-04-13

Disabling tremor is common in patients with multiple sclerosis (MS). Data from animal model experiments and subjective and small objective studies involving patients suggest that cannabis may be an effective treatment for tremor associated with MS. To our knowledge, there are no published double-blind randomized controlled trials of cannabis as a treatment for tremor in MS patients. The authors conducted a randomized double-blind placebo-controlled crossover trial to examine the effect of oral cannador (cannabis extract) on 14 patients with MS with upper limb tremors. There were eight women and six men, with a mean age of 45 years and mean Expanded Disability Status Scale score of 6.25. Patients were randomly assigned to receive each treatment and the doses escalated over a 2-week period before each assessment. The primary outcome was change on a tremor index, measured using a validated tremor rating scale. The study was powered to detect a functionally significant 50% improvement in the tremor index. Secondary outcomes included accelerometry, an ataxia scale, spiral drawing, finger tapping, and nine-hole pegboard test performance. Analysis of the data showed no significant improvement in any of the objective measures of upper limb tremor with cannabis extract compared to placebo. Finger tapping was faster on placebo compared to cannabis extract (p < 0.02). However, there was a nonsignificant trend for patients to experience more subjective relief from their tremors while on cannabis extract compared to placebo. Cannabis extract does not produce a functionally significant improvement in MS-associated tremor.

Results of the Thailand Warm-Cloud Hygroscopic Particle Seeding Experiment.

NASA Astrophysics Data System (ADS)

Silverman, Bernard A.; Sukarnjanaset, Wathana

2000-07-01

A randomized, warm-rain enhancement experiment was carried out during 1995-98 in the Bhumibol catchment area in northwestern Thailand. The experiment was conducted in accordance with a randomized, floating single-target design. The seeding targets were semi-isolated, warm convective clouds, contained within a well-defined experimental unit, that, upon qualification, were selected for seeding or not seeding with calcium chloride particles in a random manner. The seeding was done by dispensing the calcium chloride particles at an average rate of 21 kg km1 per seeding pass into the updrafts of growing warm convective clouds (about 1-2 km above cloud base) that have not yet developed or, at most, have just started to develop a precipitation radar echo. The experiment was carried out by the Bureau of Royal Rainmaking and Agricultural Aviation (BRRAA) of the Ministry of Agriculture and Cooperatives as part of its Applied Atmospheric Resources Research Program, Phase 2.During the 4 yr of the experiment, a total of 67 experimental units (34 seeded and 33 nonseeded units) were qualified in accordance with the experimental design. Volume-scan data from a 10-cm Doppler radar at 5-min intervals were used to track each experimental unit, from which various radar-estimated properties of the experimental units were obtained. The statistical evaluation of the experiment was based on a rerandomization analysis of the single ratio of seeded to unseeded experimental unit lifetime properties. In 1997, the BRRAA acquired two sophisticated King Air 350 cloud-physics aircraft, providing the opportunity to obtain physical measurements of the aerosol characteristics of the environment in which the warm clouds grow, of the hydrometeor characteristics of seeded and unseeded clouds, and of the calcium chloride seeding plume dimensions and particle size distribution-information directly related to the effectiveness of the seeding conceptual model that was not directly available up to then.The evaluation of the Thailand warm-rain enhancement experiment has provided statistically significant evidence and supporting physical evidence that the seeding of warm convective clouds with calcium chloride particles produced more rain than was produced by their unseeded counterparts. An exploratory analysis of the time evolution of the seeding effects resulted in a significant revision to the seeding conceptual model.

Effect of complementation of cattle cooling systems with feedline soakers on lactating dairy cows in a desert environment.

PubMed

Ortiz, X A; Smith, J F; Bradford, B J; Harner, J P; Oddy, A

2011-02-01

Two experiments were conducted on a commercial dairy farm in eastern Saudi Arabia to investigate the effects of Korral Kool (KK; Korral Kool Inc., Mesa, AZ) cattle cooling systems complemented with feedline soakers on core body temperature (CBT) of dairy cows. In both experiments, cows had access to KK 24h/d. In the first experiment, 7 primiparous and 6 multiparous lactating Holstein dairy cows were assigned to 1 of 2 pens, which were assigned randomly to treatment sequence over 4 d in a switchback design. Soakers were on (ON24) or off (OFF24) for 24h/d. For the second experiment, 20 multiparous lactating Holstein cows were assigned randomly to 1 of 2 pens, which were assigned randomly to treatment sequence in a switchback design. This experiment lasted 4 d and feedline soakers alternately remained off or were on (ON12) for 12h/d. In experiment 1, average ambient temperature was 30 ± 0.9°C and average relative humidity was 44 ± 14% (mean ± SD). Feedline soakers complementing KK systems for 24 h/d decreased the mean CBT of lactating dairy cows compared with KK systems alone (38.80 vs. 38.98 ± 0.061°C, respectively). A significant treatment by time interaction was found. The greatest treatment effects occurred at 2100 h; treatment means at this time were 39.26 and 38.85 ± 0.085°C for OFF24 and ON24 treatments, respectively. In experiment 2, average ambient temperature was 35 ± 1.5°C and average relative humidity was 33 ± 16%. Feedline soakers running for 12 h/d significantly decreased the mean 24-h CBT from 39.16 to 38.99 ± 0.084°C. Treatment by time interaction was also significant; the greatest treatment effects occurred at 1500 h, when ON12 reduced CBT from 39.38 to 38.81 ± 0.088°C. These results demonstrate that complementing the KK system with feedline soakers decreased the CBT of dairy cows housed in desert environments. However, the combined systems were not sufficient to lower CBT to normal temperatures in this extreme environment. Copyright © 2011 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Feeling the future: A meta-analysis of 90 experiments on the anomalous anticipation of random future events.

PubMed

Bem, Daryl; Tressoldi, Patrizio; Rabeyron, Thomas; Duggan, Michael

2015-01-01

In 2011, one of the authors (DJB) published a report of nine experiments in the Journal of Personality and Social Psychology purporting to demonstrate that an individual's cognitive and affective responses can be influenced by randomly selected stimulus events that do not occur until after his or her responses have already been made and recorded, a generalized variant of the phenomenon traditionally denoted by the term precognition. To encourage replications, all materials needed to conduct them were made available on request. We here report a meta-analysis of 90 experiments from 33 laboratories in 14 countries which yielded an overall effect greater than 6 sigma, z = 6.40, p = 1.2 × 10 (-10 ) with an effect size (Hedges' g) of 0.09. A Bayesian analysis yielded a Bayes Factor of 5.1 × 10 (9), greatly exceeding the criterion value of 100 for "decisive evidence" in support of the experimental hypothesis. When DJB's original experiments are excluded, the combined effect size for replications by independent investigators is 0.06, z = 4.16, p = 1.1 × 10 (-5), and the BF value is 3,853, again exceeding the criterion for "decisive evidence." The number of potentially unretrieved experiments required to reduce the overall effect size of the complete database to a trivial value of 0.01 is 544, and seven of eight additional statistical tests support the conclusion that the database is not significantly compromised by either selection bias or by intense " p-hacking"-the selective suppression of findings or analyses that failed to yield statistical significance. P-curve analysis, a recently introduced statistical technique, estimates the true effect size of the experiments to be 0.20 for the complete database and 0.24 for the independent replications, virtually identical to the effect size of DJB's original experiments (0.22) and the closely related "presentiment" experiments (0.21). We discuss the controversial status of precognition and other anomalous effects collectively known as psi.

Introducing rapid diagnostic tests for malaria into drug shops in Uganda: design and implementation of a cluster randomized trial.

PubMed

Mbonye, Anthony K; Magnussen, Pascal; Chandler, Clare I R; Hansen, Kristian S; Lal, Sham; Cundill, Bonnie; Lynch, Caroline A; Clarke, Siân E

2014-07-29

An intervention was designed to introduce rapid diagnostics tests for malaria (mRDTs) into registered drug shops in Uganda to encourage rational and appropriate treatment of malaria with artemisinin-based combination therapy (ACT). We conducted participatory training of drug shop vendors and implemented supporting interventions to orientate local communities (patients) and the public sector (health facility staff and district officials) to the behavioral changes in diagnosis, treatment and referral being introduced in drug shops. The intervention was designed to be evaluated through a cluster randomized trial. In this paper, we present detailed design, implementation and evaluation experiences in order to help inform future studies of a complex nature. Three preparatory studies (formative, baseline and willingness-to-pay) were conducted to explore perceptions on diagnosis and treatment of malaria at drug shops, and affordable prices for mRDTs and ACTs in order to inform the design of the intervention and implementation modalities. The intervention required careful design with the intention to be acceptable, sustainable and effective. Critical components of intervention were: community sensitization and creating awareness, training of drug shop vendors to diagnose malaria with mRDTs, treat and refer customers to formal health facilities, giving pre-referral rectal artesunate and improved record-keeping. The primary outcome was the proportion of patients receiving appropriately-targeted treatment with ACT, evaluated against microscopy on a research blood slide. Introducing mRDTs in drug shops may seem simple, but our experience of intervention design, conduct and evaluation showed this to be a complex process requiring multiple interventions and evaluation components drawing from a combination of epidemiological, social science and health economics methodologies. The trial was conducted in phases sequenced such that each benefited from the other. The main challenges in designing this trial were maintaining a balance between a robust intervention to support effective behaviour change and introducing practices that would be sustainable in a real-life situation in tropical Africa; as well as achieving a detailed evaluation without inadvertently influencing prescribing behaviour. NCT01194557 registered with ClinicalTrials.gov 2 September 2010.

Unbiased feature selection in learning random forests for high-dimensional data.

PubMed

Nguyen, Thanh-Tung; Huang, Joshua Zhexue; Nguyen, Thuy Thi

2015-01-01

Random forests (RFs) have been widely used as a powerful classification method. However, with the randomization in both bagging samples and feature selection, the trees in the forest tend to select uninformative features for node splitting. This makes RFs have poor accuracy when working with high-dimensional data. Besides that, RFs have bias in the feature selection process where multivalued features are favored. Aiming at debiasing feature selection in RFs, we propose a new RF algorithm, called xRF, to select good features in learning RFs for high-dimensional data. We first remove the uninformative features using p-value assessment, and the subset of unbiased features is then selected based on some statistical measures. This feature subset is then partitioned into two subsets. A feature weighting sampling technique is used to sample features from these two subsets for building trees. This approach enables one to generate more accurate trees, while allowing one to reduce dimensionality and the amount of data needed for learning RFs. An extensive set of experiments has been conducted on 47 high-dimensional real-world datasets including image datasets. The experimental results have shown that RFs with the proposed approach outperformed the existing random forests in increasing the accuracy and the AUC measures.

Predictors of nicotine withdrawal symptoms: findings from the first randomized smoking cessation trial in a low-income country setting.

PubMed

Ben Taleb, Ziyad; Ward, Kenneth D; Asfar, Taghrid; Jaber, Rana; Auf, Rehab; Maziak, Wasim

2016-07-01

To identify predictors of nicotine withdrawal symptoms among smokers who participated in a randomized cessation trial in a low-income country. We analyzed data from 269 smokers who participated in a randomized, placebo-controlled smoking cessation trial conducted in primary healthcare in Aleppo, Syria. All participants received behavioral counseling and were randomized to receive either 6 weeks of nicotine or placebo patch and were followed for one year. Throughout the study, lower total withdrawal score was associated with greater education (p = 0.044), older age of smoking initiation (p = 0.017), lower nicotine dependence (p = 0.024), higher confidence in ability to quit (p = 0.020), lower reported depression (p < 0.001), higher adherence to patch (p = 0.026), belief of receiving nicotine patches rather than placebo (p = 0.011), and waterpipe use (p = 0.047). Lower nicotine dependence, greater educational attainment, higher confidence in ability to quit and waterpipe use predict lower withdrawal severity. Waterpipe smoking may serve as a barrier to smoking cessation efforts in countries where its use is highly prevalent. Further, expectancies about the effects of pharmacotherapy appear to mediate the experience of nicotine withdrawal.

General Framework for Effect Sizes in Cluster Randomized Experiments

ERIC Educational Resources Information Center

VanHoudnos, Nathan

2016-01-01

Cluster randomized experiments are ubiquitous in modern education research. Although a variety of modeling approaches are used to analyze these data, perhaps the most common methodology is a normal mixed effects model where some effects, such as the treatment effect, are regarded as fixed, and others, such as the effect of group random assignment…

Pigeons' Choices between Fixed-Interval and Random-Interval Schedules: Utility of Variability?

ERIC Educational Resources Information Center

Andrzejewski, Matthew E.; Cardinal, Claudia D.; Field, Douglas P.; Flannery, Barbara A.; Johnson, Michael; Bailey, Kathleen; Hineline, Philip N.

2005-01-01

Pigeons' choosing between fixed-interval and random-interval schedules of reinforcement was investigated in three experiments using a discrete-trial procedure. In all three experiments, the random-interval schedule was generated by sampling a probability distribution at an interval (and in multiples of the interval) equal to that of the…

The relationships between hand coupling force and vibration biodynamic responses of the hand-arm system.

PubMed

Pan, Daniel; Xu, Xueyan S; Welcome, Daniel E; McDowell, Thomas W; Warren, Christopher; Wu, John; Dong, Ren G

2018-06-01

This study conducted two series of experiments to investigate the relationships between hand coupling force and biodynamic responses of the hand-arm system. In the first experiment, the vibration transmissibility on the system was measured as a continuous function of grip force while the hand was subjected to discrete sinusoidal excitations. In the second experiment, the biodynamic responses of the system subjected to a broadband random vibration were measured under five levels of grip forces and a combination of grip and push forces. This study found that the transmissibility at each given frequency increased with the increase in the grip force before reaching a maximum level. The transmissibility then tended to plateau or decrease when the grip force was further increased. This threshold force increased with an increase in the vibration frequency. These relationships remained the same for both types of vibrations. The implications of the experimental results are discussed. Practitioner Summary: Shocks and vibrations transmitted to the hand-arm system may cause injuries and disorders of the system. How to take hand coupling force into account in the risk assessment of vibration exposure remains an important issue for further studies. This study is designed and conducted to help resolve this issue.

Unexpected consequences: women's experiences of a self-hypnosis intervention to help with pain relief during labour.

PubMed

Finlayson, Kenneth; Downe, Soo; Hinder, Susan; Carr, Helen; Spiby, Helen; Whorwell, Peter

2015-09-25

Self-hypnosis is becoming increasingly popular as a means of labour pain management. Previous studies have produced mixed results. There are very few data on women's views and experiences of using hypnosis in this context. As part of a randomized controlled trial of self-hypnosis for intra-partum pain relief (the SHIP Trial) we conducted qualitative interviews with women randomized to the intervention arm to explore their views and experiences of using self-hypnosis during labour and birth. Participants were randomly selected from the intervention arm of the study, which consisted of two antenatal self-hypnosis training sessions and a supporting CD that women were encouraged to listen to daily from 32 weeks gestation until the birth of their baby. Those who consented were interviewed in their own homes 8-12 weeks after birth. Following transcription, the interviews were analysed iteratively and emerging concepts were discussed amongst the authors to generate organizing themes. These were then used to develop a principal organizing metaphor or global theme, in a process known as thematic networks analysis. Of the 343 women in the intervention group, 48 were invited to interview, and 16 were interviewed over a 12 month period from February 2012 to January 2013. Coding of the data and subsequent analysis revealed a global theme of 'unexpected consequences', supported by 5 organising themes, 'calmness in a climate of fear', 'from sceptic to believer', 'finding my space', 'delays and disappointments' and 'personal preferences'. Most respondents reported positive experiences of self-hypnosis and highlighted feelings of calmness, confidence and empowerment. They found the intervention to be beneficial and used a range of novel strategies to personalize their self-hypnosis practice. Occasionally women reported feeling frustrated or disappointed when their relaxed state was misinterpreted by midwives on admission or when their labour and birth experiences did not match their expectations. The women in this study generally appreciated antenatal self-hypnosis training and found it to be beneficial during labour and birth. The state of focused relaxation experienced by women using the technique needs to be recognized by providers if the intervention is to be implemented into the maternity service.

The impact of being bullied at school on psychological distress and work engagement in a community sample of adult workers in Japan

PubMed Central

Iwanaga, Mai; Imamura, Kotaro; Shimazu, Akihito

2018-01-01

Objective The aim of this study was to investigate the long-term impact of being bullied at school on current psychological distress and work engagement in adulthood among Japanese workers. We hypothesized that workers who had been bullied at school could have higher psychological distress and lower work engagement compared to those who had not been bullied. Methods We used data from the Japanese Study on Stratification, Health, Income, and Neighborhood (J-SHINE) project, conducted from July 2010 to February 2011 in Japan. This survey randomly selected the local residents around a metropolitan area in Japan. Of 13,920 adults originally selected, 4,317 people participated this survey, and the total response rate was 31%. The self-administered questionnaires assessed current psychological distress (K6), work engagement (UWES), the experiences of being bullied in elementary or junior high school and other covariates. Statistical analyses were conducted only for workers. Hierarchical multiple regression analyses were conducted to determine associations between experiences of being bullied at school and psychological distress/work engagement, with six steps. Result Statistical analysis was conducted for 3,111 workers. The number of respondents who reported being bullied in elementary or junior high school was 1,318 (42%). We found that the experience of being bullied at school was significantly associated with high psychological distress in adulthood (β = .079, p = < .0001); however, the work engagement scores of respondents who were bullied were significantly higher than for people who were not bullied at school (β = .068, p = < .0001), after adjusting all covariates. Conclusion Being bullied at school was positively associated with both psychological distress and work engagement in a sample of workers. Being bullied at school may be a predisposing factor for psychological distress, as previously reported. The higher levels of work engagement among people who experienced being bullied at school may be because some of them might have overcome the experience to gain more psychological resilience. PMID:29746552

The impact of being bullied at school on psychological distress and work engagement in a community sample of adult workers in Japan.

PubMed

Iwanaga, Mai; Imamura, Kotaro; Shimazu, Akihito; Kawakami, Norito

2018-01-01

The aim of this study was to investigate the long-term impact of being bullied at school on current psychological distress and work engagement in adulthood among Japanese workers. We hypothesized that workers who had been bullied at school could have higher psychological distress and lower work engagement compared to those who had not been bullied. We used data from the Japanese Study on Stratification, Health, Income, and Neighborhood (J-SHINE) project, conducted from July 2010 to February 2011 in Japan. This survey randomly selected the local residents around a metropolitan area in Japan. Of 13,920 adults originally selected, 4,317 people participated this survey, and the total response rate was 31%. The self-administered questionnaires assessed current psychological distress (K6), work engagement (UWES), the experiences of being bullied in elementary or junior high school and other covariates. Statistical analyses were conducted only for workers. Hierarchical multiple regression analyses were conducted to determine associations between experiences of being bullied at school and psychological distress/work engagement, with six steps. Statistical analysis was conducted for 3,111 workers. The number of respondents who reported being bullied in elementary or junior high school was 1,318 (42%). We found that the experience of being bullied at school was significantly associated with high psychological distress in adulthood (β = .079, p = < .0001); however, the work engagement scores of respondents who were bullied were significantly higher than for people who were not bullied at school (β = .068, p = < .0001), after adjusting all covariates. Being bullied at school was positively associated with both psychological distress and work engagement in a sample of workers. Being bullied at school may be a predisposing factor for psychological distress, as previously reported. The higher levels of work engagement among people who experienced being bullied at school may be because some of them might have overcome the experience to gain more psychological resilience.

Short term effectiveness and experiences of a peer guided web-based self-management intervention for young adults with juvenile idiopathic arthritis.

PubMed

Ammerlaan, Judy; van Os-Medendorp, Harmieke; de Boer-Nijhof, Nienke; Scholtus, Lieske; Kruize, Aike A; van Pelt, Philomine; Prakken, Berent; Bijlsma, Hans

2017-10-13

A web-based self-management intervention guided by peer-trainers was developed to support young adults' self-management in coping with Juvenile Idiopathic Arthritis (JIA). To investigate its effectiveness, a randomized controlled trial (RCT) was conducted. In addition, the content of the chat and participants' goals were studied to identify underlying processes. An RCT with a six-month follow up period was conducted among 72 young adults with JIA, aged between 16 and 25 years old, randomly assigned to the intervention or to the usual care control group. After 24 weeks, in both groups 24 participants completed all measurements. Intentions to treat analyses were carried out by means of linear mixed models for longitudinal measurements. With self-efficacy as primary outcome, self-management, disease activity, quality of life, absenteeism of school/work, health care medication use and adherence to the intervention were studied. The participants' goals, personal achievements, interactions on the chat, and their appreciation of the intervention were analyzed using thematic analyses. No significant differences were found on self-efficacy, quality of life, and self-management between the participants of the control group and the intervention group. In the intervention group, modeling and sharing experiences were the most recognized themes. Fifty-five goals were formulated and divided into the following categories: improvement and maintaining balance, setting and recognizing boundaries, communicating and coping with incomprehension. Adherence, appreciation of the own learning experience, and personal achievements were rated positively. The web-based intervention did not lead to an improvement of self-efficacy. However, additional qualitative analyses showed that the intervention was appreciated and valuable for the participants. More research is needed on how to measure the added value of this intervention compared to the usual care. Trial registration number NTR4679 .

[The results of a randomized open multicenter comparative study on the tolerability and safety of gilenya (fingolimod) in patients with remitting multiple sclerosis].

PubMed

Popova, E V; Boyko, A N; Boyko, O V

2015-01-01

At the present time, disease modifying drugs (DMD) for treatment of patients with multiple sclerosis are used to reduce the risk of exacerbations and, consequently, slowing the progression of disability in accordance to treatment standards. However, the application of the first line of this therapy is not always successful. In these situations, patients receive second-line DMD. Fingolimod is one of the second-line drugs in Russia. To gain experience in using fingolimod in routine neurological practice, we have conducted a post-marketing research - GIMN.

Accelerated lifetime test of vibration isolator made of Metal Rubber material

NASA Astrophysics Data System (ADS)

Ao, Hongrui; Ma, Yong; Wang, Xianbiao; Chen, Jianye; Jiang, Hongyuan

2017-01-01

The Metal Rubber material (MR) is a kind of material with nonlinear damping characteristics for its application in the field of aerospace, petrochemical industry and so on. The study on the lifetime of MR material is impendent to its application in engineering. Based on the dynamic characteristic of MR, the accelerated lifetime experiments of vibration isolators made of MR working under random vibration load were conducted. The effects of structural parameters of MR components on the lifetime of isolators were studied and modelled with the fitting curves of degradation data. The lifetime prediction methods were proposed based on the models.

Asymptotic approximation method of force reconstruction: Application and analysis of stationary random forces

NASA Astrophysics Data System (ADS)

Sanchez, J.

2018-06-01

In this paper, the application and analysis of the asymptotic approximation method to a single degree-of-freedom has recently been produced. The original concepts are summarized, and the necessary probabilistic concepts are developed and applied to single degree-of-freedom systems. Then, these concepts are united, and the theoretical and computational models are developed. To determine the viability of the proposed method in a probabilistic context, numerical experiments are conducted, and consist of a frequency analysis, analysis of the effects of measurement noise, and a statistical analysis. In addition, two examples are presented and discussed.

Two randomized trials provide no consistent evidence for nonmusical cognitive benefits of brief preschool music enrichment.

PubMed

Mehr, Samuel A; Schachner, Adena; Katz, Rachel C; Spelke, Elizabeth S

2013-01-01

Young children regularly engage in musical activities, but the effects of early music education on children's cognitive development are unknown. While some studies have found associations between musical training in childhood and later nonmusical cognitive outcomes, few randomized controlled trials (RCTs) have been employed to assess causal effects of music lessons on child cognition and no clear pattern of results has emerged. We conducted two RCTs with preschool children investigating the cognitive effects of a brief series of music classes, as compared to a similar but non-musical form of arts instruction (visual arts classes, Experiment 1) or to a no-treatment control (Experiment 2). Consistent with typical preschool arts enrichment programs, parents attended classes with their children, participating in a variety of developmentally appropriate arts activities. After six weeks of class, we assessed children's skills in four distinct cognitive areas in which older arts-trained students have been reported to excel: spatial-navigational reasoning, visual form analysis, numerical discrimination, and receptive vocabulary. We initially found that children from the music class showed greater spatial-navigational ability than did children from the visual arts class, while children from the visual arts class showed greater visual form analysis ability than children from the music class (Experiment 1). However, a partial replication attempt comparing music training to a no-treatment control failed to confirm these findings (Experiment 2), and the combined results of the two experiments were negative: overall, children provided with music classes performed no better than those with visual arts or no classes on any assessment. Our findings underscore the need for replication in RCTs, and suggest caution in interpreting the positive findings from past studies of cognitive effects of music instruction.

How cannabis causes paranoia: using the intravenous administration of ∆9-tetrahydrocannabinol (THC) to identify key cognitive mechanisms leading to paranoia.

PubMed

Freeman, Daniel; Dunn, Graham; Murray, Robin M; Evans, Nicole; Lister, Rachel; Antley, Angus; Slater, Mel; Godlewska, Beata; Cornish, Robert; Williams, Jonathan; Di Simplicio, Martina; Igoumenou, Artemis; Brenneisen, Rudolf; Tunbridge, Elizabeth M; Harrison, Paul J; Harmer, Catherine J; Cowen, Philip; Morrison, Paul D

2015-03-01

Paranoia is receiving increasing attention in its own right, since it is a central experience of psychotic disorders and a marker of the health of a society. Paranoia is associated with use of the most commonly taken illicit drug, cannabis. The objective was to determine whether the principal psychoactive ingredient of cannabis-∆(9)-tetrahydrocannabinol (THC)-causes paranoia and to use the drug as a probe to identify key cognitive mechanisms underlying paranoia. A randomized, placebo-controlled, between-groups test of the effects of intravenous THC was conducted. A total of 121 individuals with paranoid ideation were randomized to receive placebo, THC, or THC preceded by a cognitive awareness condition. Paranoia was assessed extensively via a real social situation, an immersive virtual reality experiment, and standard self-report and interviewer measures. Putative causal factors were assessed. Principal components analysis was used to create a composite paranoia score and composite causal variables to be tested in a mediation analysis. THC significantly increased paranoia, negative affect (anxiety, worry, depression, negative thoughts about the self), and a range of anomalous experiences, and reduced working memory capacity. The increase in negative affect and in anomalous experiences fully accounted for the increase in paranoia. Working memory changes did not lead to paranoia. Making participants aware of the effects of THC had little impact. In this largest study of intravenous THC, it was definitively demonstrated that the drug triggers paranoid thoughts in vulnerable individuals. The most likely mechanism of action causing paranoia was the generation of negative affect and anomalous experiences. © The Author 2014. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center.

Two Randomized Trials Provide No Consistent Evidence for Nonmusical Cognitive Benefits of Brief Preschool Music Enrichment

PubMed Central

Mehr, Samuel A.; Schachner, Adena; Katz, Rachel C.; Spelke, Elizabeth S.

2013-01-01

Young children regularly engage in musical activities, but the effects of early music education on children's cognitive development are unknown. While some studies have found associations between musical training in childhood and later nonmusical cognitive outcomes, few randomized controlled trials (RCTs) have been employed to assess causal effects of music lessons on child cognition and no clear pattern of results has emerged. We conducted two RCTs with preschool children investigating the cognitive effects of a brief series of music classes, as compared to a similar but non-musical form of arts instruction (visual arts classes, Experiment 1) or to a no-treatment control (Experiment 2). Consistent with typical preschool arts enrichment programs, parents attended classes with their children, participating in a variety of developmentally appropriate arts activities. After six weeks of class, we assessed children's skills in four distinct cognitive areas in which older arts-trained students have been reported to excel: spatial-navigational reasoning, visual form analysis, numerical discrimination, and receptive vocabulary. We initially found that children from the music class showed greater spatial-navigational ability than did children from the visual arts class, while children from the visual arts class showed greater visual form analysis ability than children from the music class (Experiment 1). However, a partial replication attempt comparing music training to a no-treatment control failed to confirm these findings (Experiment 2), and the combined results of the two experiments were negative: overall, children provided with music classes performed no better than those with visual arts or no classes on any assessment. Our findings underscore the need for replication in RCTs, and suggest caution in interpreting the positive findings from past studies of cognitive effects of music instruction. PMID:24349171

Metformin monotherapy in youth with recent onset type 2 diabetes: experience from the prerandomization run-in phase of the TODAY study.

PubMed

Laffel, Lori; Chang, Nancy; Grey, Margaret; Hale, Dan; Higgins, Laurie; Hirst, Kathryn; Izquierdo, Roberto; Larkin, Mary; Macha, Christina; Pham, Trang; Wauters, Aimee; Weinstock, Ruth S

2012-08-01

TODAY (Treatment Options for type 2 Diabetes in Adolescents and Youth) is a federally funded multicenter randomized clinical trial comparing three treatments of youth onset type 2 diabetes. To describe the experience of youth participating in a 2-6 month run-in period in preparation for randomization into TODAY. An ethnically diverse sample of 927 youth, 65.4% females, aged 13.7 ± 2.0 yr old, with type 2 diabetes for a median of 2 months (0.7-7.8 months, 25th-75th percentiles). A run-in period was conducted to achieve HbA1c <8% with metformin monotherapy and diabetes education, and to evaluate adherence to pill taking, visit attendance, and other procedures. At entry, mean body mass index (BMI) and z-BMI were 35.6 ± 7.7 and 2.3 ± 0.4, respectively, mean HbA1c was 7.7 ± 2.2%, only 42.5% were on a hypoglycemic treatment, and 35.6% had HbA1c ≥8%. Comorbid conditions were common; 18.8% had hypertension, 24.2% had elevated cholesterol, and 6.5% had abnormal liver enzymes. After a median 71 d of run-in, 90.9% had HbA1c <8%, 77.9% had HbA1c <7%, and 46.4% had HbA1c <6%. Of the 772 youth achieving the target HbA1c <8%, 704 (91.2%) were randomized; non-adherence to metformin treatment was the main cause for non-randomization. Youth proceeding to randomization decreased weight by 0.68 kg and HbA1c by 1.45% compared to a weight gain of 0.71 kg and HbA1c decrease of 0.74% in the non-randomized youth (p = 0.01 in both cases). However, change in z-BMI was not significantly different between the two groups. Most youth with recent onset type 2 diabetes can achieve target HbA1c <8.0% with short-term metformin monotherapy and standard diabetes education (ClinicalTrials.gov identifier: NCT00081328). © 2012 John Wiley & Sons A/S.

Effect of texture randomization on the slip and interfacial robustness in turbulent flows over superhydrophobic surfaces

NASA Astrophysics Data System (ADS)

Seo, Jongmin; Mani, Ali

2018-04-01

Superhydrophobic surfaces demonstrate promising potential for skin friction reduction in naval and hydrodynamic applications. Recent developments of superhydrophobic surfaces aiming for scalable applications use random distribution of roughness, such as spray coating and etched process. However, most previous analyses of the interaction between flows and superhydrophobic surfaces studied periodic geometries that are economically feasible only in laboratory-scale experiments. In order to assess the drag reduction effectiveness as well as interfacial robustness of superhydrophobic surfaces with randomly distributed textures, we conduct direct numerical simulations of turbulent flows over randomly patterned interfaces considering a range of texture widths w+≈4 -26 , and solid fractions ϕs=11 %-25 % . Slip and no-slip boundary conditions are implemented in a pattern, modeling the presence of gas-liquid interfaces and solid elements. Our results indicate that slip of randomly distributed textures under turbulent flows is about 30 % less than those of surfaces with aligned features of the same size. In the small texture size limit w+≈4 , the slip length of the randomly distributed textures in turbulent flows is well described by a previously introduced Stokes flow solution of randomly distributed shear-free holes. By comparing DNS results for patterned slip and no-slip boundary against the corresponding homogenized slip length boundary conditions, we show that turbulent flows over randomly distributed posts can be represented by an isotropic slip length in streamwise and spanwise direction. The average pressure fluctuation on a gas pocket is similar to that of the aligned features with the same texture size and gas fraction, but the maximum interface deformation at the leading edge of the roughness element is about twice as large when the textures are randomly distributed. The presented analyses provide insights on implications of texture randomness on drag reduction performance and robustness of superhydrophobic surfaces.

Child Health and Neighborhood Conditions: Results from a Randomized Housing Voucher Experiment

ERIC Educational Resources Information Center

Fortson, Jane G.; Sanbonmatsu, Lisa

2010-01-01

Using data from the Moving to Opportunity randomized housing voucher experiment, we estimate the direct effects of housing and neighborhood quality on child health. We show that, five years after random assignment, housing mobility has little impact on overall health status, asthma, injuries, and body mass index. The few effects that we observe…

Multivariable regression analysis of list experiment data on abortion: results from a large, randomly-selected population based study in Liberia.

PubMed

Moseson, Heidi; Gerdts, Caitlin; Dehlendorf, Christine; Hiatt, Robert A; Vittinghoff, Eric

2017-12-21

The list experiment is a promising measurement tool for eliciting truthful responses to stigmatized or sensitive health behaviors. However, investigators may be hesitant to adopt the method due to previously untestable assumptions and the perceived inability to conduct multivariable analysis. With a recently developed statistical test that can detect the presence of a design effect - the absence of which is a central assumption of the list experiment method - we sought to test the validity of a list experiment conducted on self-reported abortion in Liberia. We also aim to introduce recently developed multivariable regression estimators for the analysis of list experiment data, to explore relationships between respondent characteristics and having had an abortion - an important component of understanding the experiences of women who have abortions. To test the null hypothesis of no design effect in the Liberian list experiment data, we calculated the percentage of each respondent "type," characterized by response to the control items, and compared these percentages across treatment and control groups with a Bonferroni-adjusted alpha criterion. We then implemented two least squares and two maximum likelihood models (four total), each representing different bias-variance trade-offs, to estimate the association between respondent characteristics and abortion. We find no clear evidence of a design effect in list experiment data from Liberia (p = 0.18), affirming the first key assumption of the method. Multivariable analyses suggest a negative association between education and history of abortion. The retrospective nature of measuring lifetime experience of abortion, however, complicates interpretation of results, as the timing and safety of a respondent's abortion may have influenced her ability to pursue an education. Our work demonstrates that multivariable analyses, as well as statistical testing of a key design assumption, are possible with list experiment data, although with important limitations when considering lifetime measures. We outline how to implement this methodology with list experiment data in future research.

Random sampling of constrained phylogenies: conducting phylogenetic analyses when the phylogeny is partially known.

PubMed

Housworth, E A; Martins, E P

2001-01-01

Statistical randomization tests in evolutionary biology often require a set of random, computer-generated trees. For example, earlier studies have shown how large numbers of computer-generated trees can be used to conduct phylogenetic comparative analyses even when the phylogeny is uncertain or unknown. These methods were limited, however, in that (in the absence of molecular sequence or other data) they allowed users to assume that no phylogenetic information was available or that all possible trees were known. Intermediate situations where only a taxonomy or other limited phylogenetic information (e.g., polytomies) are available are technically more difficult. The current study describes a procedure for generating random samples of phylogenies while incorporating limited phylogenetic information (e.g., four taxa belong together in a subclade). The procedure can be used to conduct comparative analyses when the phylogeny is only partially resolved or can be used in other randomization tests in which large numbers of possible phylogenies are needed.

ASSISTments Dataset from Multiple Randomized Controlled Experiments

ERIC Educational Resources Information Center

Selent, Douglas; Patikorn, Thanaporn; Heffernan, Neil

2016-01-01

In this paper, we present a dataset consisting of data generated from 22 previously and currently running randomized controlled experiments inside the ASSISTments online learning platform. This dataset provides data mining opportunities for researchers to analyze ASSISTments data in a convenient format across multiple experiments at the same time.…

The Question of Education Science: "Experiment"ism Versus "Experimental"ism

ERIC Educational Resources Information Center

Howe, Kenneth R.

2005-01-01

The ascendant view in the current debate about education science -- experimentism -- is a reassertion of the randomized experiment as the methodological gold standard. Advocates of this view have ignored, not answered, long-standing criticisms of the randomized experiment: its frequent impracticality, its lack of external validity, its confinement…

Statistical Analysis Experiment for Freshman Chemistry Lab.

ERIC Educational Resources Information Center

Salzsieder, John C.

1995-01-01

Describes a laboratory experiment dissolving zinc from galvanized nails in which data can be gathered very quickly for statistical analysis. The data have sufficient significant figures and the experiment yields a nice distribution of random errors. Freshman students can gain an appreciation of the relationships between random error, number of…

Processing of Fear and Anger Facial Expressions: The Role of Spatial Frequency

PubMed Central

Comfort, William E.; Wang, Meng; Benton, Christopher P.; Zana, Yossi

2013-01-01

Spatial frequency (SF) components encode a portion of the affective value expressed in face images. The aim of this study was to estimate the relative weight of specific frequency spectrum bandwidth on the discrimination of anger and fear facial expressions. The general paradigm was a classification of the expression of faces morphed at varying proportions between anger and fear images in which SF adaptation and SF subtraction are expected to shift classification of facial emotion. A series of three experiments was conducted. In Experiment 1 subjects classified morphed face images that were unfiltered or filtered to remove either low (<8 cycles/face), middle (12–28 cycles/face), or high (>32 cycles/face) SF components. In Experiment 2 subjects were adapted to unfiltered or filtered prototypical (non-morphed) fear face images and subsequently classified morphed face images. In Experiment 3 subjects were adapted to unfiltered or filtered prototypical fear face images with the phase component randomized before classifying morphed face images. Removing mid frequency components from the target images shifted classification toward fear. The same shift was observed under adaptation condition to unfiltered and low- and middle-range filtered fear images. However, when the phase spectrum of the same adaptation stimuli was randomized, no adaptation effect was observed. These results suggest that medium SF components support the perception of fear more than anger at both low and high level of processing. They also suggest that the effect at high-level processing stage is related more to high-level featural and/or configural information than to the low-level frequency spectrum. PMID:23637687

Exploring Women's Preferences for the Mode of Delivery in Twin Gestations: Results of the Twin Birth Study.

PubMed

Murray-Davis, Beth; McVittie, Jennifer; Barrett, Jon F; Hutton, Eileen K

2016-12-01

The Twin Birth Study, an international, multi-center randomized controlled trial was conducted to compare the risks of planned cesarean with planned vaginal delivery for twin pregnancies. The aim of this component of the trial was to understand participants' perspectives of study participation and preferences for the mode of delivery. A mixed-methods questionnaire was distributed to study participants 3 months after giving birth. The questionnaire contained Likert scales and open-ended questions about the experience of being enrolled in a clinical trial and of childbirth, including the mode of delivery. Quantitative data were analyzed using SAS to generate descriptive statistics. Qualitative data were analyzed to identify categories and themes. Ninety-one percent of trial participants completed the questionnaire. Across all groups, the majority of women would participate in a study like this one again if given the opportunity. Main benefits of participating were as follows: benefits to one and one's babies, altruism, and receiving quality care. Randomization for the mode of delivery was challenging for women because of the desire to be involved in decision-making. Findings related to childbirth experience and the mode of delivery demonstrated a preference for vaginal birth across all groups. Those who had a vaginal birth were more satisfied with their birth experience. This study provides evidence to inform practitioners about what women who have twin pregnancies like or dislike about birth and their desire for involvement in decision-making. Vaginal birth was preferred across all study groups and was associated with greater satisfaction with childbirth experience. © 2016 Wiley Periodicals, Inc.

Video requirements for remote medical diagnosis

NASA Technical Reports Server (NTRS)

Davis, J. G.

1974-01-01

Minimal television system requirements for medical telediagnosis were studied. The experiment was conducted with the aid of a simulated telemedicine system. The first step involved making high quality videotape recordings of actual medical examinations conducted by a skilled nurse under the direction of a physician watching on closed circuit television. These recordings formed the baseline for the study. Next, these videotape recordings were electronically degraded to simulate television systems of less than broadcast quality. Finally, the baseline and degraded video recordings were shown (via a statistically randomized procedure) to a large number of physicians who attempted to reach a correct medical diagnosis and to visually recognize key physical signs for each patient. By careful scoring and analysis of the results of these viewings, the pictorial and diagnostic limitations as a function of technical video characteristics were to be defined.

Ionic conductivity and dielectric relaxation in Y doped La2Mo2O9 oxide-ion conductors

NASA Astrophysics Data System (ADS)

Paul, T.; Ghosh, A.

2014-10-01

In this work, we have studied electrical conductivity and dielectric properties of polycrystalline La2-xYxMo2O9 (0.05 ≤ x ≤ 0.3) compounds in the temperature range from 358 K to 1088 K and the frequency range from 10 Hz to 3 GHz. The bulk and grain boundary contributions to the overall conductivity of these compounds show Arrhenius type behavior at low temperatures. The random free-energy barrier model has been used to analyze the frequency dependence of the conductivity. The charge carrier relaxation time and its activation energy have been determined from the analysis of the conductivity spectra using this model. The results obtained from the random free-energy barrier model satisfy Barton-Nakajima-Namikawa relation. The conduction mechanism has been also predicted using random free-energy barrier model and the scaling formalism. We have observed that the dielectric relaxation peaks arise from the diffusion of oxygen ions via vacancies.

Theory of electrical conductivity and dielectric permittivity of highly aligned graphene-based nanocomposites.

PubMed

Xia, Xiaodong; Hao, Jia; Wang, Yang; Zhong, Zheng; Weng, George J

2017-05-24

Highly aligned graphene-based nanocomposites are of great interest due to their excellent electrical properties along the aligned direction. Graphene fillers in these composites are not necessarily perfectly aligned, but their orientations are highly confined to a certain angle, [Formula: see text] with 90° giving rise to the randomly oriented state and 0° to the perfectly aligned one. Recent experiments have shown that electrical conductivity and dielectric permittivity of highly aligned graphene-polymer nanocomposites are strongly dependent on this distribution angle, but at present no theory seems to exist to address this issue. In this work we present a new effective-medium theory that is derived from the underlying physical process including the effects of graphene orientation, filler loading, aspect ratio, percolation threshold, interfacial tunneling, and Maxwell-Wagner-Sillars polarization, to determine these two properties. The theory is formulated in the context of preferred orientational average. We highlight this new theory with an application to rGO/epoxy nanocomposites, and demonstrate that the calculated in-plane and out-of-plane conductivity and permittivity are in agreement with the experimental data as the range of graphene orientations changes from the randomly oriented to the highly aligned state. We also show that the percolation thresholds of highly aligned graphene nanocomposites are in general different along the planar and the normal directions, but they converge into a single one when the statistical distribution of graphene fillers is spherically symmetric.

Estimates of genetics and phenotypics parameters for the yield and quality of soybean seeds.

PubMed

Zambiazzi, E V; Bruzi, A T; Guilherme, S R; Pereira, D R; Lima, J G; Zuffo, A M; Ribeiro, F O; Mendes, A E S; Godinho, S H M; Carvalho, M L M

2017-09-27

Estimating genotype x environment (GxE) parameters for quality and yield in soybean seed grown in different environments in Minas Gerais State was the goal of this study, as well as to evaluate interaction effects of GxE for soybean seeds yield and quality. Seeds were produced in three locations in Minas Gerais State (Lavras, Inconfidentes, and Patos de Minas) in 2013/14 and 2014/15 seasons. Field experiments were conducted in randomized blocks in a factorial 17 x 6 (GxE), and three replications. Seed yield and quality were evaluated for germination in substrates paper and sand, seedling emergence, speed emergency index, mechanical damage by sodium hypochlorite, electrical conductivity, speed aging, vigor and viability of seeds by tetrazolium test in laboratory using completely randomized design. Quadratic component genotypic, GXE variance component, genotype determination coefficient, genetic variation coefficient and environmental variation coefficient were estimated using the Genes software. Percentage analysis of genotypes contribution, environments and genotype x environment interaction were conducted by sites combination two by two and three sites combination, using the R software. Considering genotypes selection of broad adaptation, TMG 1179 RR, CD 2737 RR, and CD 237 RR associated better yield performance at high physical and physiological potential of seed. Environmental effect was more expressive for most of the characters related to soybean seed quality. GxE interaction effects were expressive though genotypes did not present coincidental behavior in different environments.

Random Resistor Network Model of Minimal Conductivity in Graphene

NASA Astrophysics Data System (ADS)

Cheianov, Vadim V.; Fal'Ko, Vladimir I.; Altshuler, Boris L.; Aleiner, Igor L.

2007-10-01

Transport in undoped graphene is related to percolating current patterns in the networks of n- and p-type regions reflecting the strong bipolar charge density fluctuations. Finite transparency of the p-n junctions is vital in establishing the macroscopic conductivity. We propose a random resistor network model to analyze scaling dependencies of the conductance on the doping and disorder, the quantum magnetoresistance and the corresponding dephasing rate.

Deception and Shopping Behavior Among Current Cigarette Smokers: A Web-Based, Randomized Virtual Shopping Experiment.

PubMed

Dutra, Lauren McCarl; Nonnemaker, James; Taylor, Nathaniel; Kim, Annice E

2018-06-29

Virtual stores can be used to identify influences on consumer shopping behavior. Deception is one technique that may be used to attempt to increase the realism of virtual stores. The objective of the experiment was to test whether the purchasing behavior of participants in a virtual shopping task varied based on whether they were told that they would receive the products they selected in a virtual convenience store (a form of deception) or not. We recruited a US national sample of 402 adult current smokers by email from an online panel of survey participants. They completed a fully automated randomized virtual shopping experiment with a US $15 or US $20 budget in a Web-based virtual convenience store. We told a random half of participants that they would receive the products they chose in the virtual store or the cash equivalent (intervention condition), and the other random half simply to conduct a shopping task (control condition). We tested for differences in demographics, tobacco use behaviors, and in-store purchases (outcome variable, assessed by questionnaire) by experimental condition. The characteristics of the participants (398/402, 99.0% with complete data) were comparable across conditions except that the intervention group contained slightly more female participants (103/197, 52.3%) than the control group (84/201, 41.8%; P=.04). We did not find any other significant differences in any other demographic variables or tobacco use, or in virtual store shopping behaviors, including purchasing any tobacco (P=.44); purchasing cigarettes (P=.16), e-cigarettes (P=.54), cigars (P=.98), or smokeless tobacco (P=.72); amount spent overall (P=.63) or on tobacco (P=.66); percentage of budget spent overall (P=.84) or on tobacco (P=.74); number of total items (P=.64) and tobacco items purchased (P=.54); or total time spent in the store (P=.07). We found that telling participants that they will receive the products they select in a virtual store did not influence their purchases. This finding suggests that deception may not affect consumer behavior and, as a result, may not be necessary in virtual shopping experiments. ©Lauren McCarl Dutra, James Nonnemaker, Nathaniel Taylor, Annice E Kim. Originally published in JMIR Research Protocols (http://www.researchprotocols.org), 29.06.2018.

Comparing the onset of maxillary infiltration local anaesthesia and pain experience using the conventional technique vs. the Wand in children.

PubMed

Kandiah, P; Tahmassebi, J F

2012-11-01

This prospective, randomised, parallel, controlled study was conducted firstly to compare the onset of local anaesthesia (LA) when using the conventional technique versus the Wand computer-controlled LA and secondly to assess the pain experience in children. Thirty children were randomly allocated to the treatment group (Wand) or the control group (conventional). Lidocaine 2% with adrenaline (1:80,000) was given as a buccal infiltration. The onset of pulpal anaesthesia was tested using an analytic electric pulp tester (EPT). The pain experience during the LA was recorded using a modified visual analogue score (VAS). Median time for the onset of LA was 6.30 minutes for the control and 7.25 minutes for the Wand group. Mean pain experience score for the control group was 9.78% as opposed to 8.46% in the Wand group. Statistical analysis showed that there was no statistically significant difference in the onset of LA (p = 0.486) and the pain experience (p = 0.713) between the two groups. When placing a buccal infiltration on upper first permanent molars, the onset of LA and the pain experience was no different using the Wand and the conventional technique.

Gift from statistical learning: Visual statistical learning enhances memory for sequence elements and impairs memory for items that disrupt regularities.

PubMed

Otsuka, Sachio; Saiki, Jun

2016-02-01

Prior studies have shown that visual statistical learning (VSL) enhances familiarity (a type of memory) of sequences. How do statistical regularities influence the processing of each triplet element and inserted distractors that disrupt the regularity? Given that increased attention to triplets induced by VSL and inhibition of unattended triplets, we predicted that VSL would promote memory for each triplet constituent, and degrade memory for inserted stimuli. Across the first two experiments, we found that objects from structured sequences were more likely to be remembered than objects from random sequences, and that letters (Experiment 1) or objects (Experiment 2) inserted into structured sequences were less likely to be remembered than those inserted into random sequences. In the subsequent two experiments, we examined an alternative account for our results, whereby the difference in memory for inserted items between structured and random conditions is due to individuation of items within random sequences. Our findings replicated even when control letters (Experiment 3A) or objects (Experiment 3B) were presented before or after, rather than inserted into, random sequences. Our findings suggest that statistical learning enhances memory for each item in a regular set and impairs memory for items that disrupt the regularity. Copyright © 2015 Elsevier B.V. All rights reserved.

Effect of a Website That Presents Patients' Experiences on Self-Efficacy and Patient Competence of Colorectal Cancer Patients: Web-Based Randomized Controlled Trial.

PubMed

Giesler, Jürgen M; Keller, Bettina; Repke, Tim; Leonhart, Rainer; Weis, Joachim; Muckelbauer, Rebecca; Rieckmann, Nina; Müller-Nordhorn, Jacqueline; Lucius-Hoene, Gabriele; Holmberg, Christine

2017-10-13

Patients often seek other patients' experiences with the disease. The Internet provides a wide range of opportunities to share and learn about other people's health and illness experiences via blogs or patient-initiated online discussion groups. There also exists a range of medical information devices that include experiential patient information. However, there are serious concerns about the use of such experiential information because narratives of others may be powerful and pervasive tools that may hinder informed decision making. The international research network DIPEx (Database of Individual Patients' Experiences) aims to provide scientifically based online information on people's experiences with health and illness to fulfill patients' needs for experiential information, while ensuring that the presented information includes a wide variety of possible experiences. The aim is to evaluate the colorectal cancer module of the German DIPEx website krankheitserfahrungen.de with regard to self-efficacy for coping with cancer and patient competence. In 2015, a Web-based randomized controlled trial was conducted using a two-group between-subjects design and repeated measures. The study sample consisted of individuals who had been diagnosed with colorectal cancer within the past 3 years or who had metastasis or recurrent disease. Outcome measures included self-efficacy for coping with cancer and patient competence. Participants were randomly assigned to either an intervention group that had immediate access to the colorectal cancer module for 2 weeks or to a waiting list control group. Outcome criteria were measured at baseline before randomization and at 2 weeks and 6 weeks. The study randomized 212 persons. On average, participants were 54 (SD 11.1) years old, 58.8% (124/211) were female, and 73.6% (156/212) had read or heard stories of other patients online before entering the study, thus excluding any influence of the colorectal cancer module on krankheitserfahrungen.de. No intervention effects were found at 2 and 6 weeks after baseline. The results of this study do not support the hypothesis that the website studied may increase self-efficacy for coping with cancer or patient competencies such as self-regulation or managing emotional distress. Possible explanations may involve characteristics of the website itself, its use by participants, or methodological reasons. Future studies aimed at evaluating potential effects of websites providing patient experiences on the basis of methodological principles such as those of DIPEx might profit from extending the range of outcome measures, from including additional measures of website usage behavior and users' motivation, and from expanding concepts, such as patient competency to include items that more directly reflect patients' perceived effects of using such a website. Clinicaltrials.gov NCT02157454; https://clinicaltrials.gov/ct2/show/NCT02157454 (Archived by WebCite at http://www.webcitation.org/6syrvwXxi). ©Jürgen M Giesler, Bettina Keller, Tim Repke, Rainer Leonhart, Joachim Weis, Rebecca Muckelbauer, Nina Rieckmann, Jacqueline Müller-Nordhorn, Gabriele Lucius-Hoene, Christine Holmberg. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 13.10.2017.

Can Principals Promote Teacher Development as Evaluators? A Case Study of Principals' Views and Experiences.

PubMed

Kraft, Matthew A; Gilmour, Allison

2016-12-01

New teacher evaluation systems have expanded the role of principals as instructional leaders, but little is known about principals' ability to promote teacher development through the evaluation process. We conducted a case study of principals' perspectives on evaluation and their experiences implementing observation and feedback cycles to better understand whether principals feel as though they are able to promote teacher development as evaluators. We conducted interviews with a stratified random sample of 24 principals in an urban district that recently implemented major reforms to its teacher evaluation system. We analyzed these interviews by drafting thematic summaries, coding interview transcripts, creating data-analytic matrices, and writing analytic memos. We found that the evaluation reforms provided a common framework and language that helped facilitate principals' feedback conversations with teachers. However, we also found that tasking principals with primary responsibility for conducting evaluations resulted in a variety of unintended consequences which undercut the quality of evaluation feedback they provided. We analyze five broad solutions to these challenges: strategically targeting evaluations, reducing operational responsibilities, providing principal training, hiring instructional coaches, and developing peer evaluation systems. The quality of feedback teachers receive through the evaluation process depends critically on the time and training evaluators have to provide individualized and actionable feedback. Districts that task principals with primary responsibility for conducting observation and feedback cycles must attend to the many implementation challenges associated with this approach in order for next-generation evaluation systems to successfully promote teacher development.

Factorial Experiments: Efficient Tools for Evaluation of Intervention Components

PubMed Central

Collins, Linda M.; Dziak, John J.; Kugler, Kari C.; Trail, Jessica B.

2014-01-01

Background An understanding of the individual and combined effects of a set of intervention components is important for moving the science of preventive medicine interventions forward. This understanding can often be achieved in an efficient and economical way via a factorial experiment, in which two or more independent variables are manipulated. The factorial experiment is a complement to the randomized controlled trial (RCT); the two designs address different research questions. Purpose This article offers an introduction to factorial experiments aimed at investigators trained primarily in the RCT. Method The factorial experiment is compared and contrasted with other experimental designs used commonly in intervention science to highlight where each is most efficient and appropriate. Results Several points are made: factorial experiments make very efficient use of experimental subjects when the data are properly analyzed; a factorial experiment can have excellent statistical power even if it has relatively few subjects per experimental condition; and when conducting research to select components for inclusion in a multicomponent intervention, interactions should be studied rather than avoided. Conclusions Investigators in preventive medicine and related areas should begin considering factorial experiments alongside other approaches. Experimental designs should be chosen from a resource management perspective, which states that the best experimental design is the one that provides the greatest scientific benefit without exceeding available resources. PMID:25092122

Empowerment of personal injury victims through the internet: design of a randomized controlled trial.

PubMed

Elbers, Nieke A; Akkermans, Arno J; Cuijpers, Pim; Bruinvels, David J

2011-02-02

Research has shown that current claims settlement process can have a negative impact on psychological and physical recovery of personal injury (PI) victims. One of the explanations for the negative impact on health is that the claims settlement process is a stressful experience and victims suffer from renewed victimization caused by the claims settlement process. PI victims can experience a lack of information, lack of involvement, lack of 'voice', and poor communication. We present the first study that aims to empower PI victims with respect to the negative impact of the claims settlement process by means of an internet intervention. The study is a two armed, randomized controlled trial (RCT), in which 170 PI victims are randomized to either the intervention or control group. The intervention group will get access to a website providing 1) an information module, so participants learn what is happening and what to expect during the claims settlement process, and 2) an e-coach module, so participants learn to cope with problems they experience during the claims settlement process. The control group will get access to a website with hyperlinks to commonly available information only. Participants will be recruited via a PI claims settlement office. Participants are included if they have been involved in a traffic accident which happened less than two years ago, and are at least 18 years old.The main study parameter is the increase of empowerment within the intervention group compared to the control group. Empowerment will be measured by the mastery scale and a self-efficacy scale. The secondary outcomes are perceived justice, burden, well being, work ability, knowledge, amount of damages, and lawyer-client communication. Data are collected at baseline (T0 measurement before randomization), at three months, six months, and twelve months after baseline. Analyses will be conducted according to the intention-to-treat principle. This study evaluates the effectiveness of an internet intervention aimed at empowerment of PI victims. The results will give more insight into the impact of compensation proceedings on health over time, and they can have important consequences for legal claims settlement. Strengths and limitations of this study are discussed. Netherlands Trial Register NTR2360.

Analyzing social experiments as implemented: A reexamination of the evidence from the HighScope Perry Preschool Program

PubMed Central

Heckman, James; Moon, Seong Hyeok; Pinto, Rodrigo; Savelyev, Peter; Yavitz, Adam

2012-01-01

Social experiments are powerful sources of information about the effectiveness of interventions. In practice, initial randomization plans are almost always compromised. Multiple hypotheses are frequently tested. “Significant” effects are often reported with p-values that do not account for preliminary screening from a large candidate pool of possible effects. This paper develops tools for analyzing data from experiments as they are actually implemented. We apply these tools to analyze the influential HighScope Perry Preschool Program. The Perry program was a social experiment that provided preschool education and home visits to disadvantaged children during their preschool years. It was evaluated by the method of random assignment. Both treatments and controls have been followed from age 3 through age 40. Previous analyses of the Perry data assume that the planned randomization protocol was implemented. In fact, as in many social experiments, the intended randomization protocol was compromised. Accounting for compromised randomization, multiple-hypothesis testing, and small sample sizes, we find statistically significant and economically important program effects for both males and females. We also examine the representativeness of the Perry study. PMID:23255883

On the mechanisms of cation injection in conducting bridge memories: The case of HfO{sub 2} in contact with noble metal anodes (Au, Cu, Ag)

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

Saadi, M.; CNRS, LTM, F-38000 Grenoble; El Manar University, LMOP, 2092 Tunis

Resistance switching is studied in HfO{sub 2} as a function of the anode metal (Au, Cu, and Ag) in view of its application to resistive memories (resistive random access memories, RRAM). Current-voltage (I-V) and current-time (I-t) characteristics are presented. For Au anodes, resistance transition is controlled by oxygen vacancies (oxygen-based resistive random access memory, OxRRAM). For Ag anodes, resistance switching is governed by cation injection (Conducting Bridge random access memory, CBRAM). Cu anodes lead to an intermediate case. I-t experiments are shown to be a valuable tool to distinguish between OxRRAM and CBRAM behaviors. A model is proposed to explainmore » the high-to-low resistance transition in CBRAMs. The model is based on the theory of low-temperature oxidation of metals (Cabrera-Mott theory). Upon electron injection, oxygen vacancies and oxygen ions are generated in the oxide. Oxygen ions are drifted to the anode, and an interfacial oxide is formed at the HfO{sub 2}/anode interface. If oxygen ion mobility is low in the interfacial oxide, a negative space charge builds-up at the HfO{sub 2}/oxide interface. This negative space charge is the source of a strong electric field across the interfacial oxide thickness, which pulls out cations from the anode (CBRAM case). Inversely, if oxygen ions migration through the interfacial oxide is important (or if the anode does not oxidize such as Au), bulk oxygen vacancies govern resistance transition (OxRRAM case).« less

A 12-week interdisciplinary rehabilitation trial in patients with gliomas - a feasibility study.

PubMed

Hansen, Anders; Søgaard, Karen; Minet, Lisbeth Rosenbek; Jarden, Jens Ole

2018-06-01

This report aims to assess the safety and feasibility of using an interdisciplinary rehabilitation intervention for a future randomized controlled trial in patients with gliomas in the initial treatment phase. We conducted an outpatient two-part rehabilitation intervention that involved six weeks of therapeutic supervised training (part one) and six weeks of unsupervised training in a local gym following a training protocol (part two). Predefined feasibility objectives of safety (100%), consent rate (>80%), drop-out (<20%), adherence (>80%) and patient satisfaction (>80%) was achieved at part one. However, the failure to meet predefined feasibility objectives of drop-out, adherence and patient satisfaction of the unsupervised intervention at part two have led to a protocol revision for a future randomized controlled trial. This study demonstrates that an intensive rehabilitation intervention of physical therapy and occupational therapy in the initial treatment phase of patients with gliomas whose Karnofsky performance status is ≥70 is safe and feasible, if relevant inclusion criteria and precautionary screening are made. With the revised protocol, we are confident that the foundation for conducting a successful randomized controlled trial among these vulnerable patients has been established. Implications for rehabilitation Brain tumors constitute some of the most challenging cancer diagnoses presenting for rehabilitation intervention. Patients with gliomas experiences limitations in physical functioning, cognition, and emotional wellbeing. In a relatively small sample this study shows that supervised physical- and occupational therapy in patients with gliomas is safe and feasible in the initial treatment phase. Patients with gliomas can potentially improve functioning through interdisciplinary rehabilitation.

A pilot randomized placebo-controlled trial of adjunctive aripiprazole for chronic PTSD in US military Veterans resistant to antidepressant treatment.

PubMed

Naylor, Jennifer C; Kilts, Jason D; Bradford, Daniel W; Strauss, Jennifer L; Capehart, Bruce P; Szabo, Steven T; Smith, Karen D; Dunn, Charlotte E; Conner, Kathryn M; Davidson, Jonathan R T; Wagner, Henry Ryan; Hamer, Robert M; Marx, Christine E

2015-05-01

Many individuals with post-traumatic stress disorder (PTSD) experience persistent symptoms despite pharmacological treatment with antidepressants. Several open-label monotherapy and adjunctive studies have suggested that aripiprazole (a second-generation antipsychotic) may have clinical utility in PTSD. However, there have been no randomized placebo-controlled trials of aripiprazole use for PTSD. We thus conducted a pilot randomized controlled trial of adjunctive aripiprazole versus placebo among Veterans with chronic PTSD serving in the US military since 11 September 2001 to assess the feasibility, safety, tolerability, and therapeutic potential of aripiprazole. Sixteen Veterans were randomized, and 14 completed at least 4 weeks of the study; 12 completed the entire 8-week trial. Outcome measures included the Clinician-Administered PTSD Scale (CAPS), PTSD Checklist, Beck Depression Inventory, Second Edition, and Positive and Negative Syndrome Scale scores. Aripiprazole was well-tolerated in this cohort, and improvements in CAPS, PTSD Checklist, Beck Depression Inventory, Second Edition, and Positive and Negative Syndrome Scale scores were as hypothesized. Although CAPS change scores did not reach statistical significance, aripiprazole outperformed placebo by 9 points on the CAPS in the last observation carried forward analysis compared with the placebo group (n = 7 per group), and by 20 points in the group randomized to aripiprazole that completed the entire study (n = 5) compared with the placebo group (n = 7). Results suggest promise for aripiprazole as an adjunctive strategy for the treatment of PTSD.

Authorization of Animal Experiments Is Based on Confidence Rather than Evidence of Scientific Rigor

PubMed Central

Nathues, Christina; Würbel, Hanno

2016-01-01

Accumulating evidence indicates high risk of bias in preclinical animal research, questioning the scientific validity and reproducibility of published research findings. Systematic reviews found low rates of reporting of measures against risks of bias in the published literature (e.g., randomization, blinding, sample size calculation) and a correlation between low reporting rates and inflated treatment effects. That most animal research undergoes peer review or ethical review would offer the possibility to detect risks of bias at an earlier stage, before the research has been conducted. For example, in Switzerland, animal experiments are licensed based on a detailed description of the study protocol and a harm–benefit analysis. We therefore screened applications for animal experiments submitted to Swiss authorities (n = 1,277) for the rates at which the use of seven basic measures against bias (allocation concealment, blinding, randomization, sample size calculation, inclusion/exclusion criteria, primary outcome variable, and statistical analysis plan) were described and compared them with the reporting rates of the same measures in a representative sub-sample of publications (n = 50) resulting from studies described in these applications. Measures against bias were described at very low rates, ranging on average from 2.4% for statistical analysis plan to 19% for primary outcome variable in applications for animal experiments, and from 0.0% for sample size calculation to 34% for statistical analysis plan in publications from these experiments. Calculating an internal validity score (IVS) based on the proportion of the seven measures against bias, we found a weak positive correlation between the IVS of applications and that of publications (Spearman’s rho = 0.34, p = 0.014), indicating that the rates of description of these measures in applications partly predict their rates of reporting in publications. These results indicate that the authorities licensing animal experiments are lacking important information about experimental conduct that determines the scientific validity of the findings, which may be critical for the weight attributed to the benefit of the research in the harm–benefit analysis. Similar to manuscripts getting accepted for publication despite poor reporting of measures against bias, applications for animal experiments may often be approved based on implicit confidence rather than explicit evidence of scientific rigor. Our findings shed serious doubt on the current authorization procedure for animal experiments, as well as the peer-review process for scientific publications, which in the long run may undermine the credibility of research. Developing existing authorization procedures that are already in place in many countries towards a preregistration system for animal research is one promising way to reform the system. This would not only benefit the scientific validity of findings from animal experiments but also help to avoid unnecessary harm to animals for inconclusive research. PMID:27911892

Authorization of Animal Experiments Is Based on Confidence Rather than Evidence of Scientific Rigor.

PubMed

Vogt, Lucile; Reichlin, Thomas S; Nathues, Christina; Würbel, Hanno

2016-12-01

Accumulating evidence indicates high risk of bias in preclinical animal research, questioning the scientific validity and reproducibility of published research findings. Systematic reviews found low rates of reporting of measures against risks of bias in the published literature (e.g., randomization, blinding, sample size calculation) and a correlation between low reporting rates and inflated treatment effects. That most animal research undergoes peer review or ethical review would offer the possibility to detect risks of bias at an earlier stage, before the research has been conducted. For example, in Switzerland, animal experiments are licensed based on a detailed description of the study protocol and a harm-benefit analysis. We therefore screened applications for animal experiments submitted to Swiss authorities (n = 1,277) for the rates at which the use of seven basic measures against bias (allocation concealment, blinding, randomization, sample size calculation, inclusion/exclusion criteria, primary outcome variable, and statistical analysis plan) were described and compared them with the reporting rates of the same measures in a representative sub-sample of publications (n = 50) resulting from studies described in these applications. Measures against bias were described at very low rates, ranging on average from 2.4% for statistical analysis plan to 19% for primary outcome variable in applications for animal experiments, and from 0.0% for sample size calculation to 34% for statistical analysis plan in publications from these experiments. Calculating an internal validity score (IVS) based on the proportion of the seven measures against bias, we found a weak positive correlation between the IVS of applications and that of publications (Spearman's rho = 0.34, p = 0.014), indicating that the rates of description of these measures in applications partly predict their rates of reporting in publications. These results indicate that the authorities licensing animal experiments are lacking important information about experimental conduct that determines the scientific validity of the findings, which may be critical for the weight attributed to the benefit of the research in the harm-benefit analysis. Similar to manuscripts getting accepted for publication despite poor reporting of measures against bias, applications for animal experiments may often be approved based on implicit confidence rather than explicit evidence of scientific rigor. Our findings shed serious doubt on the current authorization procedure for animal experiments, as well as the peer-review process for scientific publications, which in the long run may undermine the credibility of research. Developing existing authorization procedures that are already in place in many countries towards a preregistration system for animal research is one promising way to reform the system. This would not only benefit the scientific validity of findings from animal experiments but also help to avoid unnecessary harm to animals for inconclusive research.

Intraclass Correlations and Covariate Outcome Correlations for Planning Two-and Three-Level Cluster-Randomized Experiments in Education

ERIC Educational Resources Information Center

Hedges, Larry V.; Hedberg, E. C.

2013-01-01

Background: Cluster-randomized experiments that assign intact groups such as schools or school districts to treatment conditions are increasingly common in educational research. Such experiments are inherently multilevel designs whose sensitivity (statistical power and precision of estimates) depends on the variance decomposition across levels.…

Site Selection in Experiments: A Follow-Up Evaluation of Site Recruitment in Two Scale-Up Studies

ERIC Educational Resources Information Center

Tipton, Elizabeth; Fellers, Lauren; Caverly, Sarah; Vaden-Kiernan, Michael; Borman, Geoffrey; Sullivan, Kate; Ruiz de Castillo, Veronica

2015-01-01

Randomized experiments are commonly used to evaluate if particular interventions improve student achievement. While these experiments can establish that a treatment actually "causes" changes, typically the participants are not randomly selected from a well-defined population and therefore the results do not readily generalize. Three…

Intraclass Correlations and Covariate Outcome Correlations for Planning 2 and 3 Level Cluster Randomized Experiments in Education

ERIC Educational Resources Information Center

Hedges, Larry V.; Hedberg, Eric C.

2013-01-01

Background: Cluster randomized experiments that assign intact groups such as schools or school districts to treatment conditions are increasingly common in educational research. Such experiments are inherently multilevel designs whose sensitivity (statistical power and precision of estimates) depends on the variance decomposition across levels.…

Ruminative Self-Focus and Negative Affect

PubMed Central

Moberly, Nicholas J.; Watkins, Edward R.

2008-01-01

The authors conducted an experience sampling study to investigate the relationship between momentary ruminative self-focus and negative affect. Ninety-three adults recorded these variables at quasi-random intervals 8 times daily for 1 week. Scores on questionnaire measures of dispositional rumination were associated with mean levels of momentary ruminative self-focus over the experience sampling week. Concurrently, momentary ruminative self-focus was positively associated with negative affect. Cross-lagged analyses revealed that whereas ruminative self-focus predicted negative affect at a subsequent occasion, negative affect also predicted ruminative self-focus at a subsequent occasion. Decomposition of the dispositional rumination measure suggested that brooding, but not reflective pondering, was associated with higher mean levels of negative affect. Though broadly consistent with Nolen-Hoeksema's (1991) response styles theory, these results suggest that a reciprocal relationship exists between ruminative self-focus and negative affect. PMID:18489207

Can Children Have a Relationship with a Robot?

NASA Astrophysics Data System (ADS)

Beran, Tanya N.; Ramirez-Serrano, Alejandro

As the development of autonomous robots has moved towards creating social robots, children's interactions with robots will soon need to be investigated. This paper examines how children think about and attribute features of friendship to a robot. A total of 184 children between ages 5 to 16 years visiting a science centre were randomly selected to participate in an experiment with an approximate even number of boys and girls. Children were interviewed after observing a traditional small 5 degree of freedom robot arm, perform a block stacking task. A set of experiments was conducted to measure children's perceptions of affiliation with the robot. Content analysis revealed that a large majority would consider a relationship with the robot, and participate in friendship-type behaviors with it. Significant sex differences in how children ascribe characteristics of friendship to a robot were also found.

Promoting the Positive Development of Boys in High-Poverty Neighborhoods: Evidence From Four Anti-Poverty Experiments

PubMed Central

Snell, Emily K.; Castells, Nina; Duncan, Greg; Gennetian, Lisa; Magnuson, Katherine; Morris, Pamela

2012-01-01

This study uses geocoded address data and information about parent’s economic behavior and children’s development from four random-assignment welfare and anti-poverty experiments conducted during the 1990s. We find that the impacts of these welfare and anti-poverty programs on boys’ and girls’ developmental outcomes during the transition to early adolescence differ as a function of neighborhood poverty levels. The strongest positive impacts of these programs are among boys who lived in high-poverty neighborhoods at the time their parents enrolled in the studies, with smaller or non-statistically significant effects for boys in lower poverty neighborhoods and for girls across all neighborhoods. This research informs our understanding of how neighborhood context and child gender may interact with employment-based policies to affect children’s well-being. PMID:24348000

"Damaging what wasn't damaged already": psychological tension and antiretroviral adherence among HIV-infected methadone-maintained drug users.

PubMed

Batchelder, A W; Brisbane, M; Litwin, A H; Nahvi, S; Berg, K M; Arnsten, J H

2013-01-01

Active drug use among HIV-infected persons is associated with poor adherence to highly active antiretroviral therapy (HAART) and suboptimal treatment outcomes. To understand adherence experiences among HIV-infected drug users, we conducted semistructured interviews with 15 participants in a randomized controlled trial evaluating the efficacy of directly observed HAART delivered in methadone maintenance clinics. Interviews were recorded, transcribed, and thematically analyzed. We identified negative and positive psychological themes associated with both drug use and adherence. Participants described tension between negative feelings (denial, shame, and perceived isolation) and positive feelings (acceptance, motivation, empowerment, and perceived connectedness), and they associated this tension with their own drug using and adherence behaviors. Sustained antiretroviral therapy adherence may require increased emphasis on understanding the psychological experience of HIV-infected drug users.

Modeling landslide susceptibility in data-scarce environments using optimized data mining and statistical methods

NASA Astrophysics Data System (ADS)

Lee, Jung-Hyun; Sameen, Maher Ibrahim; Pradhan, Biswajeet; Park, Hyuck-Jin

2018-02-01

This study evaluated the generalizability of five models to select a suitable approach for landslide susceptibility modeling in data-scarce environments. In total, 418 landslide inventories and 18 landslide conditioning factors were analyzed. Multicollinearity and factor optimization were investigated before data modeling, and two experiments were then conducted. In each experiment, five susceptibility maps were produced based on support vector machine (SVM), random forest (RF), weight-of-evidence (WoE), ridge regression (Rid_R), and robust regression (RR) models. The highest accuracy (AUC = 0.85) was achieved with the SVM model when either the full or limited landslide inventories were used. Furthermore, the RF and WoE models were severely affected when less landslide samples were used for training. The other models were affected slightly when the training samples were limited.

Resilience in Vulnerable Populations With Type 2 Diabetes Mellitus and Hypertension: A Systematic Review and Meta-analysis.

PubMed

Pesantes, M Amalia; Lazo-Porras, María; Abu Dabrh, Abd Moain; Ávila-Ramírez, Jaime R; Caycho, María; Villamonte, Georgina Y; Sánchez-Pérez, Grecia P; Málaga, Germán; Bernabé-Ortiz, Antonio; Miranda, J Jaime

2015-09-01

Patients with chronic conditions and limited access to health care experience stressful challenges resulting from the burden of managing both their conditions and their daily life demands. Resilience provides a mechanism of adapting to stressful experiences. We conducted a systematic review and meta-analysis to synthesize the evidence about interventions to enhance resiliency in managing hypertension or type 2 diabetes in vulnerable populations and to assess the efficacy of these interventions on clinical outcomes. We searched multiple databases from early inception through February 2015 including randomized controlled trials that enrolled patients with type 2 diabetes or hypertension. All interventions that targeted resilience in vulnerable populations were included. Data were synthesized to describe the characteristics and efficacy of resiliency interventions. We pooled the total effects by calculating standardized mean difference using the random-effects model. The final search yielded 17 studies. All studies were conducted in the United States and generally targeted minority participants. Resiliency interventions used diverse strategies; discussion groups or workshops were the most common approach. Interventions aimed at enhancing the resiliency of patients from vulnerable groups are diverse. Outcomes were not fully conclusive. There was some evidence that resiliency interventions had a positive effect on hemoglobin A1C levels but not blood pressure. The incorporation of resiliency-oriented interventions into the arsenal of preventing and managing chronic conditions appears to be an opportunity that remains to be better investigated and exploited, and there is need to pursue further understanding of the core components of any intervention that claims to enhance resilience. Copyright © 2015 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

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.

Social influence and political mobilization: Further evidence from a randomized experiment in the 2012 U.S. presidential election

PubMed Central

Bond, Robert M.; Bakshy, Eytan; Eckles, Dean; Fowler, James H.

2017-01-01

A large-scale experiment during the 2010 U.S. Congressional Election demonstrated a positive effect of an online get-out-the-vote message on real world voting behavior. Here, we report results from a replication of the experiment conducted during the U.S. Presidential Election in 2012. In spite of the fact that get-out-the-vote messages typically yield smaller effects during high-stakes elections due to saturation of mobilization efforts from many sources, a significant increase in voting was again observed. Voting also increased significantly among the close friends of those who received the message to go to the polls, and the total effect on the friends was likely larger than the direct effect, suggesting that understanding social influence effects is potentially even more important than understanding the direct effects of messaging. These results replicate earlier work and they add to growing evidence that online social networks can be instrumental for spreading offline behaviors. PMID:28445476

Social influence and political mobilization: Further evidence from a randomized experiment in the 2012 U.S. presidential election.

PubMed

Jones, Jason J; Bond, Robert M; Bakshy, Eytan; Eckles, Dean; Fowler, James H

2017-01-01

A large-scale experiment during the 2010 U.S. Congressional Election demonstrated a positive effect of an online get-out-the-vote message on real world voting behavior. Here, we report results from a replication of the experiment conducted during the U.S. Presidential Election in 2012. In spite of the fact that get-out-the-vote messages typically yield smaller effects during high-stakes elections due to saturation of mobilization efforts from many sources, a significant increase in voting was again observed. Voting also increased significantly among the close friends of those who received the message to go to the polls, and the total effect on the friends was likely larger than the direct effect, suggesting that understanding social influence effects is potentially even more important than understanding the direct effects of messaging. These results replicate earlier work and they add to growing evidence that online social networks can be instrumental for spreading offline behaviors.

SAME-GENDER SEX IN THE UNITED STATES IMPACT OF T-ACASI ON PREVALENCE ESTIMATES

PubMed Central

VILLARROEL, MARIA A.; TURNER, CHARLES F.; EGGLESTON, ELIZABETH; AL-TAYYIB, ALIA; ROGERS, SUSAN M.; ROMAN, ANTHONY M.; COOLEY, PHILIP C.; GORDEK, HARPER

2011-01-01

Well-conducted telephone surveys provide an economical means of estimating the prevalence of sexual and reproductive behaviors in a population. There is, however, a nontrivial potential for bias since respondents must report sensitive information to a human interviewer. The National STD and Behavior Measurement Experiment (NSBME) evaluates a new survey technology—telephone audio computer-assisted self-interviewing (T-ACASI)—that eliminates this requirement. The NSBME embedded a randomized experiment in a survey of probability samples of 1,543 U.S. and 744 Baltimore adults ages 18 to 45. Compared with NSBME respondents interviewed by human interviewers, respondents interviewed by T-ACASI were 1.5 to 1.6 times more likely to report same-gender sexual attraction, experience, and genital contact. The impact of T-ACASI was more pronounced (odds ratio = 2.5) for residents of locales that have historically been less tolerant of same-gender sexual behaviors and for respondents in households with children (odds ratio = 3.0). PMID:21998488

Field experiment evidence of substantive, attributional, and behavioral persuasion by members of Congress in online town halls.

PubMed

Minozzi, William; Neblo, Michael A; Esterling, Kevin M; Lazer, David M J

2015-03-31

Do leaders persuade? Social scientists have long studied the relationship between elite behavior and mass opinion. However, there is surprisingly little evidence regarding direct persuasion by leaders. Here we show that political leaders can persuade their constituents directly on three dimensions: substantive attitudes regarding policy issues, attributions regarding the leaders' qualities, and subsequent voting behavior. We ran two randomized controlled field experiments testing the causal effects of directly interacting with a sitting politician. Our experiments consist of 20 online town hall meetings with members of Congress conducted in 2006 and 2008. Study 1 examined 19 small meetings with members of the House of Representatives (average 20 participants per town hall). Study 2 examined a large (175 participants) town hall with a senator. In both experiments we find that participating has significant and substantively important causal effects on all three dimensions of persuasion but no such effects on issues that were not discussed extensively in the sessions. Further, persuasion was not driven solely by changes in copartisans' attitudes; the effects were consistent across groups.

Field experiment evidence of substantive, attributional, and behavioral persuasion by members of Congress in online town halls

PubMed Central

Minozzi, William; Neblo, Michael A.; Esterling, Kevin M.; Lazer, David M. J.

2015-01-01

Do leaders persuade? Social scientists have long studied the relationship between elite behavior and mass opinion. However, there is surprisingly little evidence regarding direct persuasion by leaders. Here we show that political leaders can persuade their constituents directly on three dimensions: substantive attitudes regarding policy issues, attributions regarding the leaders’ qualities, and subsequent voting behavior. We ran two randomized controlled field experiments testing the causal effects of directly interacting with a sitting politician. Our experiments consist of 20 online town hall meetings with members of Congress conducted in 2006 and 2008. Study 1 examined 19 small meetings with members of the House of Representatives (average 20 participants per town hall). Study 2 examined a large (175 participants) town hall with a senator. In both experiments we find that participating has significant and substantively important causal effects on all three dimensions of persuasion but no such effects on issues that were not discussed extensively in the sessions. Further, persuasion was not driven solely by changes in copartisans’ attitudes; the effects were consistent across groups. PMID:25775516

A low-order model for wave propagation in random waveguides

NASA Astrophysics Data System (ADS)

Millet, Christophe; Bertin, Michael; Bouche, Daniel

2014-11-01

In numerical modeling of infrasound propagation in the atmosphere, the wind and temperature profiles are usually obtained as a result of matching atmospheric models to empirical data and thus inevitably involve some random errors. In the present approach, the sound speed profiles are considered as random functions and the wave equation is solved using a reduced-order model, starting from the classical normal mode technique. We focus on the asymptotic behavior of the transmitted waves in the weakly heterogeneous regime (the coupling between the wave and the medium is weak), with a fixed number of propagating modes that can be obtained by rearranging the eigenvalues by decreasing Sobol indices. The most important feature of the stochastic approach lies in the fact that the model order can be computed to satisfy a given statistical accuracy whatever the frequency. The statistics of a transmitted broadband pulse are computed by decomposing the original pulse into a sum of modal pulses that can be described by a front pulse stabilization theory. The method is illustrated on two large-scale infrasound calibration experiments, that were conducted at the Sayarim Military Range, Israel, in 2009 and 2011.

The Effect of Group Discussion-based Education on Self-management of Adults with Type 2 Diabetes Mellitus Compared with Usual Care: A Randomized Control Trial.

PubMed

Habibzadeh, Hosein; Sofiani, Akbar; Alilu, Leyla; Gillespie, Mark

2017-11-01

We sought to determine the effect of group discussion-based education on the self-management capability of patients with type 2 diabetes in Iran. This randomized control trial was conducted on 90 patients with type 2 diabetes. Participants were allocated randomly into one of two groups; intervention and control. The intervention group received the group discussion-based education while the control group received routine care only. The Lin's self-management questionnaire was completed at baseline and three months post-intervention. Statistical analysis, including the use of independent t -test, identified that in comparison to the control group, significant increases were observed in the scores of self-organization ( t =11.24, p < 0.001), self-adjustment ( t = 7.53, p < 0.001), interaction with health experts ( t = 7.31, p < 0.001), blood sugar self-monitoring ( t = 6.42, p < 0.001), adherence to the proposed diet ( t = 5.22, p < 0.001), and total self-management ( t = 10.82, p < 0.001) in the intervention group. Sharing experiences through group discussions and receiving instructive feedback can improve the ability to self-manage diabetes.

Culturally targeted patient navigation for increasing african americans' adherence to screening colonoscopy: a randomized clinical trial.

PubMed

Jandorf, Lina; Braschi, Caitlyn; Ernstoff, Elizabeth; Wong, Carrie R; Thelemaque, Linda; Winkel, Gary; Thompson, Hayley S; Redd, William H; Itzkowitz, Steven H

2013-09-01

Patient navigation has been an effective intervention to increase cancer screening rates. This study focuses on predicting outcomes of screening colonoscopy for colorectal cancer among African Americans using different patient navigation formats. In a randomized clinical trial, patients more than 50 years of age without significant comorbidities were randomized into three navigation groups: peer-patient navigation (n = 181), pro-patient navigation (n = 123), and standard (n = 46). Pro-patient navigations were health care professionals who conducted culturally targeted navigation, whereas peer-patient navigations were community members trained in patient navigation who also discussed their personal experiences with screening colonoscopy. Two assessments gathered sociodemographic, medical, and intrapersonal information. Screening colonoscopy completion rate was 75.7% across all groups with no significant differences in completion between the three study arms. Annual income more than $10,000 was an independent predictor of screening colonoscopy adherence. Unexpectedly, low social influence also predicted screening colonoscopy completion. In an urban African American population, patient navigation was effective in increasing screening colonoscopy rates to 15% above the national average, regardless of patient navigation type or content. Because patient navigation successfully increases colonoscopy adherence, cultural targeting may not be necessary in some populations.

Inhibition of angiotensin-converting enzyme increases oestradiol production in ewes submitted to oestrous synchronization protocol.

PubMed

Costa, A s; Junior, A S; Viana, G E N; Muratori, M C S; Reis, A M; Costa, A P R

2014-10-01

This study aimed at evaluating the effects of angiotensin-converting enzyme inhibitor (enalapril) and angiotensin II antagonist (valsartan) on the oestradiol and progesterone production in ewes submitted to oestrous synchronization protocol. The animals were weighed and randomly divided into three groups (n = 7). A pre-experiment conducted to verify the effectiveness and toxicity of enalapril (0.5 mg/kg LW) and valsartan (2.2 mg/kg LW) showed that, in the doses used, these drugs were effective in reducing blood pressure without producing toxic effects. In the experiment, all animals were subjected to oestrous synchronization protocol during 12 days. On D10, D11 and D12, animals received saline, enalapril or valsartan (same doses of the pre-experiment), according to the group randomly divided. The hormonal analysis showed an increase in oestradiol on the last day of the protocol (D12) in animals that received enalapril (p < 0.05), but not in other groups, without changing the concentration of progesterone in any of the treatments. It is concluded that valsartan and enalapril are safe and effective subcutaneously for use in sheep and that the angiotensin-converting enzyme (ACE) inhibition with enalapril leads to an increase in oestradiol production near ovulation without changing the concentration of progesterone. This shows that ACE inhibition may be a useful tool in reproductive biotechnologies involving induction and synchronization of oestrus and ovulation in sheep. © 2014 Blackwell Verlag GmbH.

Reference Values of Within-District Intraclass Correlations of Academic Achievement by District Characteristics: Results from a Meta-Analysis of District-Specific Values

ERIC Educational Resources Information Center

Hedberg, E. C.; Hedges, Larry V.

2014-01-01

Randomized experiments are often considered the strongest designs to study the impact of educational interventions. Perhaps the most prevalent class of designs used in large scale education experiments is the cluster randomized design in which entire schools are assigned to treatments. In cluster randomized trials (CRTs) that assign schools to…

Simulation can contribute a part of cardiorespiratory physiotherapy clinical education: two randomized trials.

PubMed

Blackstock, Felicity C; Watson, Kathryn M; Morris, Norman R; Jones, Anne; Wright, Anthony; McMeeken, Joan M; Rivett, Darren A; O'Connor, Vivienne; Peterson, Raymond F; Haines, Terry P; Watson, Geoffrey; Jull, Gwendolen Anne

2013-02-01

Simulated learning environments (SLEs) are used worldwide in health professional education, including physiotherapy, to train certain attributes and skills. To date, no randomized controlled trial (RCT) has evaluated whether education in SLEs can partly replace time in the clinical environment for physiotherapy cardiorespiratory practice. Two independent single-blind multi-institutional RCTs were conducted in parallel using a noninferiority design. Participants were volunteer physiotherapy students (RCT 1, n = 176; RCT 2, n = 173) entering acute care cardiorespiratory physiotherapy clinical placements. Two SLE models were investigated as follows: RCT 1, 1 week in SLE before 3 weeks of clinical immersion; RCT 2, 2 weeks of interspersed SLE/clinical immersion (equivalent to 1 SLE week) within the 4-week clinical placement. Students in each RCT were stratified on academic grade and randomly allocated to an SLE plus clinical immersion or clinical immersion control group. The primary outcome was competency to practice measured in 2 clinical examinations using the Assessment of Physiotherapy Practice. Secondary outcomes were student perception of experience and clinical educator and patient rating of student performance. There were no significant differences in student competency between the SLE and control groups in either RCT, although students in the interspersed group (RCT 2) achieved a higher score in 5 of 7 Assessment of Physiotherapy Practice standards (all P < 0.05). Students rated the SLE experience positively. Clinical educators and patients reported comparability between groups. An SLE can replace clinical time in cardiorespiratory physiotherapy practice. Part education in the SLE satisfied clinical competency requirements, and all stakeholders were satisfied.

Supplemental nicotine preloading for smoking cessation in posttraumatic stress disorder: Results from a randomized controlled trial.

PubMed

Dennis, Paul A; Kimbrel, Nathan A; Dedert, Eric A; Beckham, Jean C; Dennis, Michelle F; Calhoun, Patrick S

2016-08-01

Individuals with posttraumatic stress disorder (PTSD) are more likely to smoke and more likely to relapse following a quit attempt than individuals without PTSD. Thus, there is a significant need to study promising interventions that might improve quit rates for smokers with PTSD. One such intervention, supplemental nicotine patch-preloading, entails the use of nicotine replacement therapy prior to quitting. Objective The objective of this study was to conduct a randomized controlled trial of the efficacy of supplemental nicotine patch-preloading among smokers with PTSD. We hypothesized that, relative to participants in the placebo condition, participants in the nicotine patch-preloading condition would: (1) smoke less and experience reduced craving for cigarettes during the nicotine patch-preloading phase; (2) experience less smoking-associated relief from PTSD symptoms and negative affect during the preloading phase; and (3) exhibit greater latency to lapse, and higher short- and long-term abstinence rates. Sixty-three smokers with PTSD were randomized to either nicotine or placebo patch for three weeks prior to their quit date. Ecological momentary assessment was used to assess craving, smoking, PTSD symptoms, and negative affect during the preloading period. Nicotine patch-preloading failed to reduce smoking or craving during the preloading phase, nor was it associated with less smoking-associated relief from PTSD symptoms and negative affect. Moreover, no differences were observed between the treatment conditions for time to lapse, 6-week abstinence, or 6-month abstinence. The findings from the present research suggest that supplemental nicotine patch-preloading is unlikely to substantially enhance quit rates among smokers with PTSD. Published by Elsevier Ltd.

Public attitudes toward child undervaccination: A randomized experiment on evaluations, stigmatizing orientations, and support for policies.

PubMed

Carpiano, Richard M; Fitz, Nicholas S

2017-07-01

Child undervaccination is a complex public health problem and a contentious social and political issue. Efforts to increase vaccination coverage require understanding how the public evaluates different reasons for child undervaccination, which may influence attitudes, stigmatizing behaviors, and support for vaccination policies. We conducted a vignette experiment with a United States national online sample (n = 1469) to investigate how and why different undervaccination actions shape evaluations (blame, anger, sympathy, differentness, credibility, dangerousness), stigmatizing orientations (social distance, discrimination), and support for particular policies (e.g., research funding, belief exemptions, fines). Each participant was randomly assigned to read one of four vignettes that described a mother who either refused vaccines, delayed vaccines, encountered social barriers to obtaining vaccines, or was up-to-date on vaccines for her child. Compared to the up-to-date condition, each undervaccination action predicted significantly more negative evaluations and stigmatizing orientations. Vaccine refusal was the most negatively appraised. Differences in social distance and discrimination were explained by negative evaluations about the parent. These evaluations and orientations predicted support for a range of policies. Negative parental evaluations were associated with increased support for more severe policies. We discuss the implications of these findings for addressing undervaccination and informing health scholarship on stigma. Copyright © 2017 Elsevier Ltd. All rights reserved.

An Examination of Strategy Implementation During Abstract Nonlinguistic Category Learning in Aphasia

PubMed Central

Kiran, Swathi

2015-01-01

Purpose Our purpose was to study strategy use during nonlinguistic category learning in aphasia. Method Twelve control participants without aphasia and 53 participants with aphasia (PWA) completed a computerized feedback-based category learning task consisting of training and testing phases. Accuracy rates of categorization in testing phases were calculated. To evaluate strategy use, strategy analyses were conducted over training and testing phases. Participant data were compared with model data that simulated complex multi-cue, single feature, and random pattern strategies. Learning success and strategy use were evaluated within the context of standardized cognitive–linguistic assessments. Results Categorization accuracy was higher among control participants than among PWA. The majority of control participants implemented suboptimal or optimal multi-cue and single-feature strategies by testing phases of the experiment. In contrast, a large subgroup of PWA implemented random patterns, or no strategy, during both training and testing phases of the experiment. Conclusions Person-to-person variability arises not only in category learning ability but also in the strategies implemented to complete category learning tasks. PWA less frequently developed effective strategies during category learning tasks than control participants. Certain PWA may have impairments of strategy development or feedback processing not captured by language and currently probed cognitive abilities. PMID:25908438

Simulated microgravity: critical review on the use of random positioning machines for mammalian cell culture.

PubMed

Wuest, Simon L; Richard, Stéphane; Kopp, Sascha; Grimm, Daniela; Egli, Marcel

2015-01-01

Random Positioning Machines (RPMs) have been used since many years as a ground-based model to simulate microgravity. In this review we discuss several aspects of the RPM. Recent technological development has expanded the operative range of the RPM substantially. New possibilities of live cell imaging and partial gravity simulations, for example, are of particular interest. For obtaining valuable and reliable results from RPM experiments, the appropriate use of the RPM is of utmost importance. The simulation of microgravity requires that the RPM's rotation is faster than the biological process under study, but not so fast that undesired side effects appear. It remains a legitimate question, however, whether the RPM can accurately and reliably simulate microgravity conditions comparable to real microgravity in space. We attempt to answer this question by mathematically analyzing the forces working on the samples while they are mounted on the operating RPM and by comparing data obtained under real microgravity in space and simulated microgravity on the RPM. In conclusion and after taking the mentioned constraints into consideration, we are convinced that simulated microgravity experiments on the RPM are a valid alternative for conducting examinations on the influence of the force of gravity in a fast and straightforward approach.

Simulated Microgravity: Critical Review on the Use of Random Positioning Machines for Mammalian Cell Culture

PubMed Central

Wuest, Simon L.; Richard, Stéphane; Kopp, Sascha

2015-01-01

Random Positioning Machines (RPMs) have been used since many years as a ground-based model to simulate microgravity. In this review we discuss several aspects of the RPM. Recent technological development has expanded the operative range of the RPM substantially. New possibilities of live cell imaging and partial gravity simulations, for example, are of particular interest. For obtaining valuable and reliable results from RPM experiments, the appropriate use of the RPM is of utmost importance. The simulation of microgravity requires that the RPM's rotation is faster than the biological process under study, but not so fast that undesired side effects appear. It remains a legitimate question, however, whether the RPM can accurately and reliably simulate microgravity conditions comparable to real microgravity in space. We attempt to answer this question by mathematically analyzing the forces working on the samples while they are mounted on the operating RPM and by comparing data obtained under real microgravity in space and simulated microgravity on the RPM. In conclusion and after taking the mentioned constraints into consideration, we are convinced that simulated microgravity experiments on the RPM are a valid alternative for conducting examinations on the influence of the force of gravity in a fast and straightforward approach. PMID:25649075

Mindfulness as an Intervention for Recalling Information from a Lecture as a Measure of Academic Performance in Higher Education: A Randomized Experiment

ERIC Educational Resources Information Center

Bennett, Rebecca Iranzo; Egan, Helen; Cook, Amy; Mantzios, Michail

2018-01-01

Higher education students experience heightened levels of stress and anxiety, and report experiencing negative thoughts and emotions, which influence information retention and recall. In a randomized experiment, we assigned participants to either a mindfulness meditation or an audiobook listening condition, and recorded the information recalled…

The Effects of Attrition on Baseline Comparability in Randomized Experiments in Education: A Meta-Analysis

ERIC Educational Resources Information Center

Valentine, Jeffrey C.; McHugh, Cathleen M.

2007-01-01

Using meta-analysis, randomized experiments in education that either clearly did or clearly did not experience student attrition were examined for the baseline comparability of groups. Results from 35 studies suggested that after attrition, the observed measures of baseline comparability of groups did not differ more than would be expected given…

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

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.

Generating random numbers by means of nonlinear dynamic systems

NASA Astrophysics Data System (ADS)

Zang, Jiaqi; Hu, Haojie; Zhong, Juhua; Luo, Duanbin; Fang, Yi

2018-07-01

To introduce the randomness of a physical process to students, a chaotic pendulum experiment was opened in East China University of Science and Technology (ECUST) on the undergraduate level in the physics department. It was shown chaotic motion could be initiated through adjusting the operation of a chaotic pendulum. By using the data of the angular displacements of chaotic motion, random binary numerical arrays can be generated. To check the randomness of generated numerical arrays, the NIST Special Publication 800-20 method was adopted. As a result, it was found that all the random arrays which were generated by the chaotic motion could pass the validity criteria and some of them were even better than the quality of pseudo-random numbers generated by a computer. Through the experiments, it is demonstrated that chaotic pendulum can be used as an efficient mechanical facility in generating random numbers, and can be applied in teaching random motion to the students.

Effects of Polymer Structure and Relaxations on Ionic Conductivity in Anion Exchange Membranes with Quaternary Ammonium Functional Groups

NASA Astrophysics Data System (ADS)

Maes, Ashley M.

Anion exchange membranes (AEMs) are of considerable interest to developers and researchers of electrochemical conversion and storage devices such as anion exchange membrane fuel cells (AAEMFCs), alkaline polymer electrolyte electrolysers, redox flow batteries and bioelectrochemical devices. AEMs are generally in competition with more established proton exchange membranes (PEMs), but offer the potential for reduction of materials costs and greater fuel flexibility across these applications. This work includes an introduction to AEMs in the context of fuel cell technologies and some key techniques for AEM characterization. There are many synthetic strategies to incorporate cationic functional groups, which promote anion transport, into a polymer matrix. Two membrane chemistries are investigated in the following chapters. The first is based on a simple synthesis procedure that produced a membrane consisting of random, crosslinked polypropylene- ran-polyethyleneimine with quaternary ammonium functional groups. This membrane had moderate chloride ionic conductivity of 0.03 S cm -1 at 95 °C and high water uptake with minimal dimensional swelling. However, the lack of control of crosslink location and density during synthesis produced a material with a very random nature, making it a poor candidate for more fundamental transport studies. The second membrane chemistry is a block copolymer with a hydrophobic and hydrophilic block. The hydrophobic block was selected to provide favorable mechanical and barrier characteristics while a hydrophilic block was selected to provide water uptake and anion conducting functionalities. Poly(vinyl benzyl trimethyl ammonium bromide)-b-poly(methylbutylene) ([PVBTMA][Br]- b-PMB) was synthesized by partners at the University of Massachusetts-Amherst with varied degrees of functionalization (DF) along the hydrophilic block, resulting in ion exchange capacities ranging from 0.77 to 2.20 mmol g -1. Water uptake, in-plane ionic conductivity and membrane morphology were measured across a series of membranes with the original bromide (Br -) counter-ion. These bulk materials characterization experiments demonstrated that this polymer structure produces well-ordered lamellar morphology with moderate water uptake and competitive ionic conductivity (ca. 40 mS cm-1 at 90 °C and 95% relative humidity). These characteristics make it an appropriate candidate for the following more fundamental investigations of ionic conductivity mechanisms. Broadband electrical spectroscopy (BES) was conducted on one [PVBTMA][Br]- b-PMB sample in the Br- form and analyzed in conjunction with thermal stability and relaxation experiments in Chapter 4. We were able to propose two separate ionic conductivity mechanisms and relate each to physical attributes of the polymer structure. A significant thermal transition was observed at Tdelta , which resulted in a dramatic drop in conductivity. In a continued effort to characterize the ionic conductivity of these block-copolymer membranes, another BES study was conducted on three samples with varying DFs. Samples were converted to hydroxide (OH- ) form so we could contrast the Br- conductivity mechanisms to those in a more relevant counter-ion form. After analysis of the electric response of the material, combined with the thermal analysis by TGA, MDSC and DMA, conductivity mechanisms were described. As in the Br- study, conductivity involves two distinct conduction pathways, sigmaEP and sigmaIP,1. Importantly, we again observed a drop in conductivity at Tdelta in each of these samples, with Tdelta decreasing as the density of functional groups along the hydrophilic block increased. It is undesirable for this transition to occur during operation in a fuel cell or other electrochemical device, so future work to investigate strategies for inhibition are recommended.

Randomized controlled trial of a six-week spiritual reminiscence intervention on hope, life satisfaction, and spiritual well-being in elderly with mild and moderate dementia.

PubMed

Wu, Li-Fen; Koo, Malcolm

2016-02-01

Reminiscence therapy has been reported to improve the well-being in patients with dementia. However, few studies have examined the effects of spiritual reminiscence, which emphasizes on reconnecting and enhancing the meaning of one's own experience, on patients with dementia. Therefore, this study aimed to investigate the effects of spiritual reminiscence on hope, life satisfaction, and spiritual well-being in elderly Taiwanese with mild or moderate dementia. A randomized controlled trial was conducted on 103 patients with mild or moderate dementia recruited from a medical center in central Taiwan. The patients were randomly assigned to either a 6-week spiritual reminiscence group (n = 53) or control group (n = 50). The Herth Hope Index, the Life Satisfaction Scale, the Spirituality Index of Well-Being were administered before and after the 6-week period. The interaction terms between group and time for the three outcome measures were found to be significant (P < 0.001), indicating that the changes over time in them were different between the intervention and control groups. Findings of this randomized controlled trial showed that hope, life satisfaction, and spiritual well-being of elderly patients with mild or moderate dementia could significantly be improved with a 6-week spiritual reminiscence intervention. Copyright © 2015 John Wiley & Sons, Ltd.

[Medical decision making in symptoms of type 2 diabetes mellitus in general practice].

PubMed

de Cruppé, W; von dem Knesebeck, O; Gerstenberger, E; Link, C; Marceau, L; Siegrist, J; Geraedts, M; McKinlay, J

2011-02-01

Patient and physician attributes influence medical decisions as non-medical factors. The current study examines the influence of patient age and gender and physicians' gender and years of clinical experience on medical decision making in patients with undiagnosed diabetes type 2. A factorial experiment was conducted to estimate the influence of patient and physician attributes. An identical physician patient encounter with a patient presenting with diabetes symptoms was videotaped with varying patient attributes. Professional actors played the "patients". A sample of 64 randomly chosen and stratified (gender and years of experience) primary care physicians was interviewed about the presented videos. Results show few significant differences in diagnostic decisions: Younger patients were asked more frequently about psychosocial problems while with older patients a cancer diagnosis was more often taken into consideration. Female physicians made an earlier second appointment date compared to male physicians. Physicians with more years of professional experience considered more often diabetes as the diagnosis than physicians with less experience. Medical decision making in patients with diabetes type 2 is only marginally influenced by patients' and physicians' characteristics under study. © Georg Thieme Verlag KG Stuttgart · New York.

Effect of vermicompost on growth, yield and nutrition status of tomato (Lycopersicum esculentum).

PubMed

Azarmi, Rasool; Ziveh, Parviz Sharifi; Satari, Mohammad Reza

2008-07-15

An experiment was conducted to determine the effects of vermicompost on growth, yield and fruit quality of tomato (Lycopersicum esculentum var. Super Beta) in a field condition. The experiment was a randomized complete block design with four replications. The different rates of vermicompost (0, 5, 10 and 15 t ha(-1)) was incorporated into the top 15 cm of soil. During experiment period, fruits were harvested twice in a week and total yield were recorded for two months. At the end of experiment, growth characteristics such as leaf number, leaf area and shoot dry weights were determined. The results revealed that addition of vermicompost at rate of 15 t ha(-1) significantly (at p < 0.05) increased growth and yield compared to control. Vermicompost with rate of 15 t ha(-1) increased EC of fruit juice and percentage of fruit dry matter up to 30 and 24%, respectively. The content of K, P, Fe and Zn in the plant tissue increased 55, 73, 32 and 36% compared to untreated plots respectively. The result of our experiment showed addition of vermicompost had significant (p < 0.05) positive effects on growth, yield and elemental content of plant as compared to control.

The effect of motivation and positive affect on ego depletion: Replenishment versus release mechanism.

PubMed

Zhu, Ze; Li, Jian; Zhang, Bo; Li, Ye; Zhang, Houcan

2017-12-01

In this study, 2 experiments were conducted to investigate whether motivation and positive affect can alleviate ego depletion and to elucidate their possible mechanisms. In Experiment 1, a crossing-out-letter task was adapted to reach an ego depletion state for Chinese participants. Participants were then randomly assigned to the extrinsic motivation group, the positive affect group or the depletion control group. After the experimental treatment, a dumbbell task was used to measure participants' remaining self-regulatory resources. The results showed that participants in the motivation and positive affect groups performed better on the dumbbell task than participants in the depletion control group. Experiment 2 was similar to Experiment 1 except that participants were asked to perform an additional unexpected dumbbell task after a neutral video following the above procedure. The results of Experiment 1 were replicated; however, participants' performance on the additional dumbbell task differed. The positive affect group performed better than the depletion control group, indicating an increase in self-regulatory resources and thus supporting the replenishment effect of positive affect. No significant difference was found between the motivation group and the depletion control group. © 2015 International Union of Psychological Science.

Economic evaluation of an experience sampling method intervention in depression compared with treatment as usual using data from a randomized controlled trial.

PubMed

Simons, Claudia J P; Drukker, Marjan; Evers, Silvia; van Mastrigt, Ghislaine A P G; Höhn, Petra; Kramer, Ingrid; Peeters, Frenk; Delespaul, Philippe; Menne-Lothmann, Claudia; Hartmann, Jessica A; van Os, Jim; Wichers, Marieke

2017-12-29

Experience sampling, a method for real-time self-monitoring of affective experiences, holds opportunities for person-tailored treatment. By focussing on dynamic patterns of positive affect, experience sampling method interventions (ESM-I) accommodate strategies to enhance personalized treatment of depression-at potentially low-costs. This study aimed to investigate the cost-effectiveness of an experience sampling method intervention in patients with depression, from a societal perspective. Participants were recruited between January 2010 and February 2012 from out-patient mental health care facilities in or near the Dutch cities of Eindhoven and Maastricht, and through local advertisements. Out-patients diagnosed with major depression (n = 101) receiving pharmacotherapy were randomized into: (i) ESM-I consisting of six weeks of ESM combined with weekly feedback regarding the individual's positive affective experiences, (ii) six weeks of ESM without feedback, or (iii) treatment as usual only. Alongside this randomised controlled trial, an economic evaluation was conducted consisting of a cost-effectiveness and a cost-utility analysis, using Hamilton Depression Rating Scale (HDRS) and quality adjusted life years (QALYs) as outcome, with willingness-to-pay threshold for a QALY set at €50,000 (based on Dutch guidelines for moderate severe to severe illnesses). The economic evaluation showed that ESM-I is an optimal strategy only when willingness to pay is around €3000 per unit HDRS and around €40,500 per QALY. ESM-I was the least favourable treatment when willingness to pay was lower than €30,000 per QALY. However, at the €50,000 willingness-to-pay threshold, ESM-I was, with a 46% probability, the most favourable treatment (base-case analysis). Sensitivity analyses confirmed the robustness of these results. We may tentatively conclude that ESM-I is a cost-effective add-on intervention to pharmacotherapy in outpatients with major depression. Netherlands Trial register, NTR1974 .

Emission Factors of Nitrous Oxide by Organic Manure Fertilizers in Japanese Upland Fields

NASA Astrophysics Data System (ADS)

Sudo, S.

2011-12-01

Preliminary data of field experiments which were conducted to estimate emission factors of nitrous oxide by organic manure fertilizers in 10 Japan-wide experiment sites, 2010 was reported. We compared nitrous oxide emission from urea as chemical fertilizers and cow manure as organic applications, in 1o Japanese prefectures of Yamagata, Fukushima, Ibaraki, Aichi, Shiga, Tokushima, Nagasaki, Kumamoto and Kagoshima. Same amounts of nitrogen were applied in organic and inorganic fertilizers in each field. In each site, 3 replication plots were organized in randomized block design with zero-nitrogen application plots. N2O gas fluxes were measured every one week or more during cultivation seasons. We also measured several soil physical and chemical parameters of inorganic nitrogen species, soil moisture contents or WFPS (Water Filled Pore Space), soil temperatures, bulk densities etc. Gas fluxes ware measured by automated Shimadzu GC-2014 ECD gas chromatograph. Soil moistures were measured by Camplel's Hydrosense in each site. Vegetation of conducting fields were cabbage in 7 fields, wheat in 1, pear orchard and onion in 1. Microorganisms' abundance was also considered to clarify N2O emission processes by the PCR-DGGE method.

Which Treatment is More Effective for Functional Ankle Instability: Strengthening or Combined Muscle Strengthening and Proprioceptive Exercises?

PubMed

Kim, Ki-Jong; Kim, Young-Eok; Jun, Hyun-Ju; Lee, Jin-Su; Ji, Sung-Ha; Ji, Sang-Goo; Seo, Tae-Hwa; Kim, Young-Ok

2014-03-01

[Purpose] The purpose of this study was to implement combined muscle strengthening and proprioceptive exercises to examine the effects of combined exercises on functional ankle instability. [Subjects and Methods] Experiments were conducted with 30 adult males and females. The study subjects were randomly assigned to either a control group (Group A), a muscle strengthening exercise group (Group B), or a combined muscle strengthening and proprioceptive exercise group (Group C) consisting of 10 subjects each. In Group A, measurements were only conducted before and after the experiment without any intervention, whereas the exercise programs for Group B and Group C were implemented three days per week for four weeks. [Results] Muscle strength showed significant increases in Groups B and C compared with the control group during plantar flexion, dorsiflexion, inversion, and eversion. The Cumberland ankle instability tool showed significant increases in Group B and Group C compared with Group A and significant increases in Group C compared with Group B. [Conclusion] Applying combined muscle strengthening and proprioceptive exercises to those who have functional ankle instability is more effective than applying only muscle strengthening exercises.

Knowledge, Attitudes, and Experiences of HIV Pre-Exposure Prophylaxis (PrEP) Trial Participants in Botswana.

PubMed

Toledo, Lauren; McLellan-Lemal, Eleanor; Henderson, Faith L; Kebaabetswe, Poloko M

2015-03-01

Recent clinical trials have shown that a daily dose of oral TDF/FTC pre-exposure prophylaxis (PrEP) is effective in reducing human immunodeficiency (HIV) risk. Understanding trial participants' perspectives about retention and PrEP adherence is critical to inform future PrEP trials and the scale-up and implementation of PrEP programs. We analyzed 53 in-depth interviews conducted in April 2010 with participants in the TDF2 study, a Phase 3, randomized, double-blind, placebo-controlled clinical trial of daily oral TDF/FTC with heterosexual men and women in Francistown and Gaborone, Botswana. We examined participants' knowledge, attitudes, and experiences of the trial, identified facilitators and barriers to enrollment and retention, and compared participant responses by study site, sex, and study drug adherence. Our findings point to several factors to consider for participant retention and adherence in PrEP trials and programs, including conducting pre-enrollment education and myth reduction counseling, providing accurate estimates of participant obligations and side effect symptoms, ensuring participant understanding of the effects of non-adherence, gauging personal commitment and interest in study outcomes, and developing a strong external social support network for participants.

Enhanced thermoelectric properties via oxygen non-stoichiometry in La2NiO4 and SrTiO3

NASA Astrophysics Data System (ADS)

Pardo, Victor; Botana, Antia S.; Bach, Paul M.; Leboran, Victor; Rivadulla, Francisco; Baldomir, Daniel

2013-03-01

We present the results of transport properties calculations and experiments on various oxides. A large enhancement of the thermoelectric properties is predicted[1] via ab initio calculations for La2NiO4+δ, with electronic-only thermoelectric figure of merit (zT) values exceeding unity for oxygen excess δ <= 0.10. The effects of lattice strain (caused, e.g. by growth of thin films on different substrates) enhance even further the thermoelectric response. A similar result is obtained at very low electron-doping in bulk SrTiO3 via oxygen removal. This is analyzed experimentally via thermal annealing that depletes oxygen (~ 1 oxygen vacancy per 106 unit cells). In both these systems, the increase in conductivity reached in the metallic limit retains a large thermopower, with the corresponding enhancement of zT . In the case of SrTiO3, experiments indicate[2] that such a small oxygen vacancy level reduces drastically the thermal conductivity by introducing random scattering centers. In the talk, we will discuss the electronic structure origin of the enhancement of the thermoelectric response and how this can be tuned. Results are general and applicable to other non-stoichiometric oxides.

Adolescent school experiences and dropout, adolescent pregnancy, and young adult deviant behavior.

PubMed

Kasen, S; Cohen, P; Brook, J S

1998-01-01

Outside of the family, schools are the most proximal socializing agent available to convey societal norms and prohibitions to young people. In some cases, a positive school experience can compensate for the antisocial influence of family and community. The present study investigated the predictive ability of school-related factors on later deviancy in a random sample of 452 US adolescents 12-18 years of age attending 150 junior or senior high schools in upstate New York and enrolled in a broader prospective study. A measure of conduct problems, obtained 2 years before measurement of school factors, was used to control for the predisposing effects of problematic behavior on later deviance. Academic achievement, academic aspirations, and a learning-focused school environment had deterrent effects on all deviant outcomes assessed--dropping out of school, adolescent pregnancy, engaging in criminal activities, criminal conviction, antisocial personality disorder, and alcohol abuse--independent of age, gender, intelligence quotient, socioeconomic status, childhood conduct problems, and proportion of deviance-oriented friends in adolescence. Given the persistence of deviant behavioral patterns of adolescence into adulthood, the systems-level influences identified in this study should be given careful attention.

A focus group study to understand biases and confounders in a cluster randomized controlled trial on low back pain in primary care in Norway.

PubMed

Werner, Erik L; Løchting, Ida; Storheim, Kjersti; Grotle, Margreth

2018-05-22

Cluster randomized controlled trials are often used in research in primary care but creates challenges regarding biases and confounders. We recently presented a study on low back pain from primary care in Norway with equal effects in the intervention and the control group. In order to understand the specific mechanisms that may produce biases in a cluster randomized trial we conducted a focus group study among the participating health care providers. The aim of this study was to understand how the participating providers themselves influenced on the study and thereby possibly on the results of the cluster randomized controlled trial. The providers were invited to share their experiences from their participation in the COPE study, from recruitment of patients to accomplishment of either the intervention or control consultations. Six clinicians from the intervention group and four from the control group took part in the focus group interviews. The group discussions focused on feasibility of the study in primary care and particularly on identifying potential biases and confounders in the study. The audio-recorded interviews were transcribed verbatim and analyzed according to a systematic text condensation. The themes for the analysis emerged from the group discussions. A personal interest for back pain, logistic factors at the clinics and an assessment of the patients' capacity to accomplish the study prior to their recruitment was reported. The providers were allowed to provide additional therapy to the intervention and it turned out that some of these could be regarded as opposed to the messages of the intervention. The providers seemed to select different items from the educational package according to personal beliefs and their perception of the patients' acceptance. The study disclosed several potential biases to the COPE study which may have impacted on the study results. Awareness of these is highly important when planning and conducting a cluster randomized controlled trial. Procedures in the recruitment of both providers and patients seem to be key factors and the providers should be aware of their role in a scientific study in order to standardize the provision of the intervention.

Predicting CD4 count changes among patients on antiretroviral treatment: Application of data mining techniques.

PubMed

Kebede, Mihiretu; Zegeye, Desalegn Tigabu; Zeleke, Berihun Megabiaw

2017-12-01

To monitor the progress of therapy and disease progression, periodic CD4 counts are required throughout the course of HIV/AIDS care and support. The demand for CD4 count measurement is increasing as ART programs expand over the last decade. This study aimed to predict CD4 count changes and to identify the predictors of CD4 count changes among patients on ART. A cross-sectional study was conducted at the University of Gondar Hospital from 3,104 adult patients on ART with CD4 counts measured at least twice (baseline and most recent). Data were retrieved from the HIV care clinic electronic database and patients` charts. Descriptive data were analyzed by SPSS version 20. Cross-Industry Standard Process for Data Mining (CRISP-DM) methodology was followed to undertake the study. WEKA version 3.8 was used to conduct a predictive data mining. Before building the predictive data mining models, information gain values and correlation-based Feature Selection methods were used for attribute selection. Variables were ranked according to their relevance based on their information gain values. J48, Neural Network, and Random Forest algorithms were experimented to assess model accuracies. The median duration of ART was 191.5 weeks. The mean CD4 count change was 243 (SD 191.14) cells per microliter. Overall, 2427 (78.2%) patients had their CD4 counts increased by at least 100 cells per microliter, while 4% had a decline from the baseline CD4 value. Baseline variables including age, educational status, CD8 count, ART regimen, and hemoglobin levels predicted CD4 count changes with predictive accuracies of J48, Neural Network, and Random Forest being 87.1%, 83.5%, and 99.8%, respectively. Random Forest algorithm had a superior performance accuracy level than both J48 and Artificial Neural Network. The precision, sensitivity and recall values of Random Forest were also more than 99%. Nearly accurate prediction results were obtained using Random Forest algorithm. This algorithm could be used in a low-resource setting to build a web-based prediction model for CD4 count changes. Copyright © 2017 Elsevier B.V. All rights reserved.

Equilibration of quantum hall edge states and its conductance fluctuations in graphene p-n junctions

NASA Astrophysics Data System (ADS)

Kumar, Chandan; Kuiri, Manabendra; Das, Anindya

2018-02-01

We report an observation of conductance fluctuations (CFs) in the bipolar regime of quantum hall (QH) plateaus in graphene (p-n-p/n-p-n) devices. The CFs in the bipolar regime are shown to decrease with increasing bias and temperature. At high temperature (above 7 K) the CFs vanishes completely and the flat quantized plateaus are recovered in the bipolar regime. The values of QH plateaus are in theoretical agreement based on full equilibration of chiral channels at the p-n junction. The amplitude of CFs for different filling factors follows a trend predicted by the random matrix theory. Although, there are mismatch in the values of CFs between the experiment and theory but at higher filling factors the experimental values become closer to the theoretical prediction. The suppression of CFs and its dependence has been understood in terms of time dependent disorders present at the p-n junctions.

Cluster randomized trials utilizing primary care electronic health records: methodological issues in design, conduct, and analysis (eCRT Study).

PubMed

Gulliford, Martin C; van Staa, Tjeerd P; McDermott, Lisa; McCann, Gerard; Charlton, Judith; Dregan, Alex

2014-06-11

There is growing interest in conducting clinical and cluster randomized trials through electronic health records. This paper reports on the methodological issues identified during the implementation of two cluster randomized trials using the electronic health records of the Clinical Practice Research Datalink (CPRD). Two trials were completed in primary care: one aimed to reduce inappropriate antibiotic prescribing for acute respiratory infection; the other aimed to increase physician adherence with secondary prevention interventions after first stroke. The paper draws on documentary records and trial datasets to report on the methodological experience with respect to research ethics and research governance approval, general practice recruitment and allocation, sample size calculation and power, intervention implementation, and trial analysis. We obtained research governance approvals from more than 150 primary care organizations in England, Wales, and Scotland. There were 104 CPRD general practices recruited to the antibiotic trial and 106 to the stroke trial, with the target number of practices being recruited within six months. Interventions were installed into practice information systems remotely over the internet. The mean number of participants per practice was 5,588 in the antibiotic trial and 110 in the stroke trial, with the coefficient of variation of practice sizes being 0.53 and 0.56 respectively. Outcome measures showed substantial correlations between the 12 months before, and after intervention, with coefficients ranging from 0.42 for diastolic blood pressure to 0.91 for proportion of consultations with antibiotics prescribed, defining practice and participant eligibility for analysis requires careful consideration. Cluster randomized trials may be performed efficiently in large samples from UK general practices using the electronic health records of a primary care database. The geographical dispersal of trial sites presents a difficulty for research governance approval and intervention implementation. Pretrial data analyses should inform trial design and analysis plans. Current Controlled Trials ISRCTN 47558792 and ISRCTN 35701810 (both registered on 17 March 2010).

Cluster randomized trials utilizing primary care electronic health records: methodological issues in design, conduct, and analysis (eCRT Study)

PubMed Central

2014-01-01

Background There is growing interest in conducting clinical and cluster randomized trials through electronic health records. This paper reports on the methodological issues identified during the implementation of two cluster randomized trials using the electronic health records of the Clinical Practice Research Datalink (CPRD). Methods Two trials were completed in primary care: one aimed to reduce inappropriate antibiotic prescribing for acute respiratory infection; the other aimed to increase physician adherence with secondary prevention interventions after first stroke. The paper draws on documentary records and trial datasets to report on the methodological experience with respect to research ethics and research governance approval, general practice recruitment and allocation, sample size calculation and power, intervention implementation, and trial analysis. Results We obtained research governance approvals from more than 150 primary care organizations in England, Wales, and Scotland. There were 104 CPRD general practices recruited to the antibiotic trial and 106 to the stroke trial, with the target number of practices being recruited within six months. Interventions were installed into practice information systems remotely over the internet. The mean number of participants per practice was 5,588 in the antibiotic trial and 110 in the stroke trial, with the coefficient of variation of practice sizes being 0.53 and 0.56 respectively. Outcome measures showed substantial correlations between the 12 months before, and after intervention, with coefficients ranging from 0.42 for diastolic blood pressure to 0.91 for proportion of consultations with antibiotics prescribed, defining practice and participant eligibility for analysis requires careful consideration. Conclusions Cluster randomized trials may be performed efficiently in large samples from UK general practices using the electronic health records of a primary care database. The geographical dispersal of trial sites presents a difficulty for research governance approval and intervention implementation. Pretrial data analyses should inform trial design and analysis plans. Trial registration Current Controlled Trials ISRCTN 47558792 and ISRCTN 35701810 (both registered on 17 March 2010). PMID:24919485

Azúcar y nervios: explanatory models and treatment experiences of Hispanics with diabetes and depression.

PubMed

Cabassa, Leopoldo J; Hansen, Marissa C; Palinkas, Lawrence A; Ell, Kathleen

2008-06-01

This study examined the explanatory models of depression, perceived relationships between diabetes and depression, and depression treatment experiences of low-income, Spanish-speaking, Hispanics with diabetes and depression. A purposive sample (n=19) was selected from participants enrolled in a randomized controlled trial conducted in Los Angeles, California (United States) testing the effectiveness of a health services quality improvement intervention. Four focus groups followed by 10 in-depth semi-structured qualitative interviews were conducted. Data were analyzed using the methodology of coding, consensus, co-occurrence, and comparison, an analytical strategy rooted in grounded theory. Depression was perceived as a serious condition linked to the accumulation of social stressors. Somatic and anxiety-like symptoms and the cultural idiom of nervios were central themes in low-income Hispanics' explanatory models of depression. The perceived reciprocal relationships between diabetes and depression highlighted the multiple pathways by which these two illnesses impact each other and support the integration of diabetes and depression treatments. Concerns about depression treatments included fears about the addictive and harmful properties of antidepressants, worries about taking too many pills, and the stigma attached to taking psychotropic medications. This study provides important insights about the cultural and social dynamics that shape low-income Hispanics' illness and treatment experiences and support the use of patient-centered approaches to reduce the morbidity and mortality associated with diabetes and depression.

“Azúcar y Nervios: Explanatory Models and Treatment Experiences of Hispanics with Diabetes and Depression”

PubMed Central

Hansen, Marissa C; Palinkas, Lawrence A; Ell, Kathleen

2008-01-01

This study examined the explanatory models of depression, perceived relationships between diabetes and depression, and depression treatment experiences of low-income, Spanish-speaking, Hispanics with diabetes and depression. A purposive sample (n =19) was selected from participants enrolled in a randomized controlled trial conducted in Los Angeles, California (US) testing the effectiveness of a health services quality improvement intervention. Four focus groups followed by 10 in-depth semi-structured qualitative interviews were conducted. Data were analyzed using the methodology of coding, consensus, co-occurrence, and comparison, an analytical strategy rooted in grounded theory. Depression was perceived as a serious condition linked to the accumulation of social stressors. Somatic and anxiety-like symptoms and the cultural idiom of nervios were central themes in low-income Hispanics’ explanatory models of depression. The perceived reciprocal relationships between diabetes and depression highlighted the multiple pathways by which these two illnesses impact each other and support the integration of diabetes and depression treatments. Concerns about depression treatments included fears about the addictive and harmful properties of antidepressants, worries about taking too many pills, and the stigma attached to taking psychotropic medications. This study provides important insights about the cultural and social dynamics that shape low-income Hispanics’ illness and treatment experiences and support the use of patient-centered approaches to reduce the morbidity and mortality associated with diabetes and depression. PMID:18339466

New Medicaid Enrollees See Health and Social Benefits in Pennsylvania's Expansion.

PubMed

Hom, Jeffrey K; Wong, Charlene; Stillson, Christian; Zha, Jessica; Cannuscio, Carolyn C; Cahill, Rachel; Grande, David

2016-01-01

Understanding how new Medicaid enrollees are approaching their own health and health care in the shifting health care landscape of the Affordable Care Act has implications for future outreach and enrollment efforts, as well as service planning for this population. The objective of this study was to explore the health care experiences and expectations of new Medicaid expansion beneficiaries in the immediate post-enrollment period. We conducted semistructured, qualitative interviews with a random sample of 40 adults in Philadelphia who had completed an application for Medicaid through a comprehensive benefits organization after January 1, 2015, when the Medicaid expansion in Pennsylvania took effect. We conducted an inductive, applied thematic analysis of interview transcripts. The new Medicaid beneficiaries described especially high levels of pent-up demand for care. Dental care was a far more pressing and motivating concern than medical care. Preventive services were also frequently mentioned. Participants anticipated that insurance would reduce both stress and financial strain and improve their experience in the health care system by raising their social standing. Participants highly valued the support of telephone application counselors in the Medicaid enrollment process to overcome bureaucratic obstacles they had encountered in the past. Dental care and preventive services appear to be high priorities for new Medicaid enrollees. Telephone outreach and enrollment support services can be an effective way to overcome past experiences with administrative barriers. © The Author(s) 2016.

Competition between rice (Oryza sativa L.) and (barnyardgrass (Echinochloa crus-galli (L.) P. Beauv.) as affected by methanol foliar application.

PubMed

Rezaeieh, Alireza D; Aminpanah, Hashem; Sadeghi, Seyed M

2015-01-01

Pot experiment was conducted in Iran, to evaluate the effect of methanol on competition between rice (Oryza sativa) and barnyardgrass (Echinochloa crus-galli). The experiment was conducted as a randomized complete block design with a factorial treatment arrangement and three replicates. Factors were two aqueous methanol foliar applications (0, and 14% v/v) and five rice: barnyardgrass ratios (100:0, 75:25, 50:50, 25:6, and 0:100). Replacement series diagrams for aboveground dry weight illustrated that 'Shiroudi' was more competitive than barnyardgrass as averaged across methanol foliar applications. When methanol was not sprayed, the lines for 'Shiroudi' and barnyardgrass intersected at 75:25 rice: barnyardgrass ratio, but when methanol was sprayed at 14% v/v, the lines for 'Shiroudi' and barnyardgrass intersect at the left of the 75:25 rice: barnyardgrass mixture proportion. These indicate that methanol application reduced competitive ability of 'Shiroudi' against barnyardgrass for aboveground biomass accumulation. At the same time, Methanol foliar application significantly reduced the relative crowding coefficient of 'Shiroudi' while simultaneously it significantly increased the relative crowding coefficient of barnyard grass. This indicates that methanol foliar application reduced the competitive ability of 'Shiroudi' against barnyardgrass for shoot biomass accumulation. This experiment illustrated that foliar spray of aqueous methanol can not be recommended for rice under weedy conditions.

New Medicaid Enrollees See Health and Social Benefits in Pennsylvania’s Expansion

PubMed Central

Hom, Jeffrey K.; Wong, Charlene; Stillson, Christian; Zha, Jessica; Cannuscio, Carolyn C.; Cahill, Rachel; Grande, David

2016-01-01

Understanding how new Medicaid enrollees are approaching their own health and health care in the shifting health care landscape of the Affordable Care Act has implications for future outreach and enrollment efforts, as well as service planning for this population. The objective of this study was to explore the health care experiences and expectations of new Medicaid expansion beneficiaries in the immediate post-enrollment period. We conducted semistructured, qualitative interviews with a random sample of 40 adults in Philadelphia who had completed an application for Medicaid through a comprehensive benefits organization after January 1, 2015, when the Medicaid expansion in Pennsylvania took effect. We conducted an inductive, applied thematic analysis of interview transcripts. The new Medicaid beneficiaries described especially high levels of pent-up demand for care. Dental care was a far more pressing and motivating concern than medical care. Preventive services were also frequently mentioned. Participants anticipated that insurance would reduce both stress and financial strain and improve their experience in the health care system by raising their social standing. Participants highly valued the support of telephone application counselors in the Medicaid enrollment process to overcome bureaucratic obstacles they had encountered in the past. Dental care and preventive services appear to be high priorities for new Medicaid enrollees. Telephone outreach and enrollment support services can be an effective way to overcome past experiences with administrative barriers. PMID:27789732

Stereoscopic visual fatigue assessment and modeling

NASA Astrophysics Data System (ADS)

Wang, Danli; Wang, Tingting; Gong, Yue

2014-03-01

Evaluation of stereoscopic visual fatigue is one of the focuses in the user experience research. It is measured in either subjective or objective methods. Objective measures are more preferred for their capability to quantify the degree of human visual fatigue without being affected by individual variation. However, little research has been conducted on the integration of objective indicators, or the sensibility of each objective indicator in reflecting subjective fatigue. The paper proposes a simply effective method to evaluate visual fatigue more objectively. The stereoscopic viewing process is divided into series of sessions, after each of which viewers rate their visual fatigue with subjective scores (SS) according to a five-grading scale, followed by tests of the punctum maximum accommodation (PMA) and visual reaction time (VRT). Throughout the entire viewing process, their eye movements are recorded by an infrared camera. The pupil size (PS) and percentage of eyelid closure over the pupil over time (PERCLOS) are extracted from the videos processed by the algorithm. Based on the method, an experiment with 14 subjects was conducted to assess visual fatigue induced by 3D images on polarized 3D display. The experiment consisted of 10 sessions (5min per session), each containing the same 75 images displayed randomly. The results show that PMA, VRT and PERCLOS are the most efficient indicators of subjective visual fatigue and finally a predictive model is derived from the stepwise multiple regressions.

Double Blind Test For Bio-Stimulation Effects On Pain Relief By Diode Laser

NASA Astrophysics Data System (ADS)

Saeki, Norio; Sembokuya, Iwajiro; Arakawa, Kazuo; Fujimasa, Iwao; Mabuchi, Kunihiko; Abe, Yuusuke; Atsumi, Kazuhiko

1989-09-01

The bio-stimulation effect of semiconductor laser on therapeutic pain relief was investigated by conducting a double blind test performed on more than one hundred patient subjects suffering from various neualgia. A compact laser therapeutic equipment with two laser probes each having 60 mW power was developed and utilized for the experiment. Each probe was driven by either the active or the dummy source selected randomly, and its results were stored in the memory for statistical processing. The therapeutic treatments including active and dummy treatments were performed on 102 subjects. The pain relief effects were confirmed for 85.5% of the subjects.

The importance of replication in wildlife research

USGS Publications Warehouse

Johnson, D.H.

2002-01-01

Wildlife ecology and management studies have been widely criticized for deficiencies in design or analysis. Manipulative experiments--with controls, randomization, and replication in space and time--provide powerful ways of learning about natural systems and establishing causal relationships, but such studies are rare in our field. Observational studies and sample surveys are more common; they also require appropriate design and analysis. More important than the design and analysis of individual studies is metareplication: replication of entire studies. Similar conclusions obtained from studies of the same phenomenon conducted under widely differing conditions will give us greater confidence in the generality of those findings than would any single study, however well designed and executed.

Inadvertently programmed bits in Samsung 128 Mbit flash devices: a flaky investigation

NASA Technical Reports Server (NTRS)

Swift, G.

2002-01-01

JPL's X2000 avionics design pioneers new territory by specifying a non-volatile memory (NVM) board based on flash memories. The Samsung 128Mb device chosen was found to demonstrate bit errors (mostly program disturbs) and block-erase failures that increase with cycling. Low temperature, certain pseudo- random patterns, and, probably, higher bias increase the observable bit errors. An experiment was conducted to determine the wearout dependence of the bit errors to 100k cycles at cold temperature using flight-lot devices (some pre-irradiated). The results show an exponential growth rate, a wide part-to-part variation, and some annealing behavior.

Conduct Problems and Peer Rejection in Childhood: A Randomized Trial of the Making Choices and Strong Families Programs

ERIC Educational Resources Information Center

Fraser, Mark W.; Day, Steven H.; Galinsky, Maeda J.; Hodges, Vanessa G.; Smokowski, Paul R.

2004-01-01

This article discusses the effectiveness of a multicomponent intervention designed to disrupt developmental processes associated with conduct problems and peer rejection in childhood. Compared with 41 children randomized to a wait list control condition, 45 children in an intervention condition received a social skills training program. At the…

Meals Enhancing Nutrition after Discharge (MEND): Findings from a Pilot Randomized Controlled Trial

PubMed Central

Campbell, Anthony D.; Godfryd, Alice; Flood, Kellie; Kitchin, Elizabeth; Kilgore, Meredith L.; Allocca, Sally; Locher, Julie L.

2016-01-01

Background After older adults experience episodes of poor health or are hospitalized, they may not return to pre-morbid eating behaviors. Furthermore, poor nutrition increases hospital readmission risk, but evidence-based interventions addressing these risks are limited. Objective The pilot study’s objective was to evaluate the feasibility of conducting a randomized controlled trial assessing a post-discharge home-delivered meals program’s impact on older adults’ nutritional intake and hospital readmissions and to assess patient acceptability and satisfaction with the program. The aims of the study were to 1) to evaluate successful recruitment, randomization, and retention of at least 80% of the 24 participants sought; 2) to compare the outcomes of hospital readmission and total daily caloric intake between participants in the intervention and control groups; and 3) to assess patient acceptability and satisfaction with the program. Design This study used a two-arm randomized controlled trial design, and baseline data were collected at enrollment; three 24-hour food recalls were collected during the intervention period; and health services utilization and intervention satisfaction was evaluated 45 days post-discharge. Participants/setting Twenty-four patients from the University of Alabama at Birmingham (UAB) Hospital’s Acute Care for Elders Unit were enrolled from May 2014 to June 2015. They were 65 or older, at risk of malnutrition, cognitively intact, able to communicate, discharged to a place where the patient or family was responsible for preparing meals, and diagnosed with congestive heart failure, chronic obstructive pulmonary disease, acute myocardial infarction, or pneumonia. Final analysis included 21 participants. Intervention The intervention group received 10 days of home-delivered meals and nutrition education; the control group received usual care and nutrition education. Main outcome measures The main outcome was intervention feasibility, measured by recruitment and retention goals. Hospital readmissions, caloric intake, and satisfaction with the intervention were also evaluated. Statistical analyses performed Univariate and bivariate parametric statistics were used to evaluate differences between groups. Goals for success were identified to assess feasibility of conducting a full-scale study, and outcomes were measured against the goals. Results 87.5% of randomized participants were retained for final data collection, indicating that this intervention study is feasible. There were no significant differences between groups for hospital readmissions; however, caloric intake during the intervention period was greater for intervention vs. control participants (1595 vs. 1235, p=.03). Participants were overwhelmingly satisfied (82–100% satisfied or very satisfied) with staff performance, meal quality, and delivery processes. Conclusions Conducting a randomized controlled trial to assess outcomes of providing home-delivered meals to older adults after hospital discharge in partnership with a small nonprofit organization is feasible and warrants future research. PMID:28065635

Long-Term Effects of Individual Development Accounts on Postsecondary Education: Follow-Up Evidence from a Randomized Experiment

ERIC Educational Resources Information Center

Grinstein-Weiss, Michal; Sherraden, Michael; Gale, William G.; Rohe, William M.; Schreiner, Mark; Key, Clinton

2013-01-01

This paper presents evidence from a randomized field experiment testing the impact of a 3-year matched savings program on educational outcomes 10 years after the start of the experiment. We examine the effect of an Individual Development Account (IDA) program on (1) educational enrollment, (2) degree completion, and (3) increased education level.…

Modeling the Impact of Control on the Attractiveness of Risk in a Prospect Theory Framework

PubMed Central

Young, Diana L.; Goodie, Adam S.; Hall, Daniel B.

2010-01-01

Many decisions involve a degree of personal control over event outcomes, which is exerted through one’s knowledge or skill. In three experiments we investigated differences in decision making between prospects based on a) the outcome of random events and b) the outcome of events characterized by control. In Experiment 1, participants estimated certainty equivalents (CEs) for bets based on either random events or the correctness of their answers to U.S. state population questions across the probability spectrum. In Experiment 2, participants estimated CEs for bets based on random events, answers to U.S. state population questions, or answers to questions about 2007 NCAA football game results. Experiment 3 extended the same procedure as Experiment 1 using a within-subjects design. We modeled data from all experiments in a prospect theory framework to establish psychological mechanisms underlying decision behavior. Participants weighted the probabilities associated with bets characterized by control so as to reflect greater risk attractiveness relative to bets based on random events, as evidenced by more elevated weighting functions under conditions of control. This research elucidates possible cognitive mechanisms behind increased risk taking for decisions characterized by control, and implications for various literatures are discussed. PMID:21278906

Modeling the Impact of Control on the Attractiveness of Risk in a Prospect Theory Framework.

PubMed

Young, Diana L; Goodie, Adam S; Hall, Daniel B

2011-01-01

Many decisions involve a degree of personal control over event outcomes, which is exerted through one's knowledge or skill. In three experiments we investigated differences in decision making between prospects based on a) the outcome of random events and b) the outcome of events characterized by control. In Experiment 1, participants estimated certainty equivalents (CEs) for bets based on either random events or the correctness of their answers to U.S. state population questions across the probability spectrum. In Experiment 2, participants estimated CEs for bets based on random events, answers to U.S. state population questions, or answers to questions about 2007 NCAA football game results. Experiment 3 extended the same procedure as Experiment 1 using a within-subjects design. We modeled data from all experiments in a prospect theory framework to establish psychological mechanisms underlying decision behavior. Participants weighted the probabilities associated with bets characterized by control so as to reflect greater risk attractiveness relative to bets based on random events, as evidenced by more elevated weighting functions under conditions of control. This research elucidates possible cognitive mechanisms behind increased risk taking for decisions characterized by control, and implications for various literatures are discussed.

Encapsulation of single cells into monodisperse droplets by fluorescence-activated droplet formation on a microfluidic chip.

PubMed

Hu, Rui; Liu, Pian; Chen, Pu; Wu, Liang; Wang, Yao; Feng, Xiaojun; Liu, Bi-Feng

2016-06-01

Random compartmentalization of cells by common droplet formation methods, i.e., T-junction and flow-focusing, results in low occupancy of droplets by single cells. To resolve this issue, a fluorescence-activated droplet formation method was developed for the on-command generation of droplets and encapsulation of single cells. In this method, droplets containing one cell were generated by switching on/off a two-phase hydrodynamic gating valve upon optical detection of single cells. To evaluate the developed method, flow visualization experiments were conducted with fluorescein. Results indicated that picoliter droplets of uniform sizes (RSD<4.9%) could be generated. Encapsulation of single fluorescent polystyrene beads demonstrated an average of 94.3% droplets contained one bead. Further application of the developed methods to the compartmentalization of individual HeLa cells indicated 82.5% occupancy of droplets by single cells, representing a 3 fold increase in comparison to random compartmentalization. Copyright © 2016 Elsevier B.V. All rights reserved.

Enhancing students’ mathematical problem posing skill through writing in performance tasks strategy

NASA Astrophysics Data System (ADS)

Kadir; Adelina, R.; Fatma, M.

2018-01-01

Many researchers have studied the Writing in Performance Task (WiPT) strategy in learning, but only a few paid attention on its relation to the problem-posing skill in mathematics. The problem-posing skill in mathematics covers problem reformulation, reconstruction, and imitation. The purpose of the present study was to examine the effect of WiPT strategy on students’ mathematical problem-posing skill. The research was conducted at a Public Junior Secondary School in Tangerang Selatan. It used a quasi-experimental method with randomized control group post-test. The samples were 64 students consists of 32 students of the experiment group and 32 students of the control. A cluster random sampling technique was used for sampling. The research data were obtained by testing. The research shows that the problem-posing skill of students taught by WiPT strategy is higher than students taught by a conventional strategy. The research concludes that the WiPT strategy is more effective in enhancing the students’ mathematical problem-posing skill compared to the conventional strategy.

Object-based change detection method using refined Markov random field

NASA Astrophysics Data System (ADS)

Peng, Daifeng; Zhang, Yongjun

2017-01-01

In order to fully consider the local spatial constraints between neighboring objects in object-based change detection (OBCD), an OBCD approach is presented by introducing a refined Markov random field (MRF). First, two periods of images are stacked and segmented to produce image objects. Second, object spectral and textual histogram features are extracted and G-statistic is implemented to measure the distance among different histogram distributions. Meanwhile, object heterogeneity is calculated by combining spectral and textual histogram distance using adaptive weight. Third, an expectation-maximization algorithm is applied for determining the change category of each object and the initial change map is then generated. Finally, a refined change map is produced by employing the proposed refined object-based MRF method. Three experiments were conducted and compared with some state-of-the-art unsupervised OBCD methods to evaluate the effectiveness of the proposed method. Experimental results demonstrate that the proposed method obtains the highest accuracy among the methods used in this paper, which confirms its validness and effectiveness in OBCD.

Building Diversified Multiple Trees for classification in high dimensional noisy biomedical data.

PubMed

Li, Jiuyong; Liu, Lin; Liu, Jixue; Green, Ryan

2017-12-01

It is common that a trained classification model is applied to the operating data that is deviated from the training data because of noise. This paper will test an ensemble method, Diversified Multiple Tree (DMT), on its capability for classifying instances in a new laboratory using the classifier built on the instances of another laboratory. DMT is tested on three real world biomedical data sets from different laboratories in comparison with four benchmark ensemble methods, AdaBoost, Bagging, Random Forests, and Random Trees. Experiments have also been conducted on studying the limitation of DMT and its possible variations. Experimental results show that DMT is significantly more accurate than other benchmark ensemble classifiers on classifying new instances of a different laboratory from the laboratory where instances are used to build the classifier. This paper demonstrates that an ensemble classifier, DMT, is more robust in classifying noisy data than other widely used ensemble methods. DMT works on the data set that supports multiple simple trees.

A randomized controlled trial of laparoscopic nissen fundoplication versus proton pump inhibitors for treatment of patients with chronic gastroesophageal reflux disease: One-year follow-up.

PubMed

Anvari, Mehran; Allen, Christopher; Marshall, John; Armstrong, David; Goeree, Ron; Ungar, Wendy; Goldsmith, Charles

2006-12-01

A randomized controlled trial conducted in patients with gastroesophageal reflux disease compared optimized medical therapy using proton pump inhibitor (n = 52) with laparoscopic Nissen fundoplication (n = 52). Patients were monitored for 1 year. The primary end point was frequency of gastroesophageal reflux dis-ease symptoms. Surgical patients had improved symptoms, pH control, and overall quality of life health index after surgery at 1 year compared with the medical group. The overall gastroesophageal reflux disease symptom score at 1 year was unchanged in the medical patients, but improved in the surgical patients. Fourteen patients in the medical arm experienced symptom relapse requiring titration of the proton pump inhibitor dose, but 6 had satisfactory symptom remission. No surgical patients required additional treatment for symptom control. Patients controlled on long-term proton pump inhibitor therapy for chronic gastroesophageal reflux disease are excellent surgical candidates and should experience improved symptom control after surgery at 1 year.

Classification of acoustic emission signals using wavelets and Random Forests : Application to localized corrosion

NASA Astrophysics Data System (ADS)

Morizet, N.; Godin, N.; Tang, J.; Maillet, E.; Fregonese, M.; Normand, B.

2016-03-01

This paper aims to propose a novel approach to classify acoustic emission (AE) signals deriving from corrosion experiments, even if embedded into a noisy environment. To validate this new methodology, synthetic data are first used throughout an in-depth analysis, comparing Random Forests (RF) to the k-Nearest Neighbor (k-NN) algorithm. Moreover, a new evaluation tool called the alter-class matrix (ACM) is introduced to simulate different degrees of uncertainty on labeled data for supervised classification. Then, tests on real cases involving noise and crevice corrosion are conducted, by preprocessing the waveforms including wavelet denoising and extracting a rich set of features as input of the RF algorithm. To this end, a software called RF-CAM has been developed. Results show that this approach is very efficient on ground truth data and is also very promising on real data, especially for its reliability, performance and speed, which are serious criteria for the chemical industry.

Investigating the origins of high multilevel resistive switching in forming free Ti/TiO2-x-based memory devices through experiments and simulations

NASA Astrophysics Data System (ADS)

Bousoulas, P.; Giannopoulos, I.; Asenov, P.; Karageorgiou, I.; Tsoukalas, D.

2017-03-01

Although multilevel capability is probably the most important property of resistive random access memory (RRAM) technology, it is vulnerable to reliability issues due to the stochastic nature of conducting filament (CF) creation. As a result, the various resistance states cannot be clearly distinguished, which leads to memory capacity failure. In this work, due to the gradual resistance switching pattern of TiO2-x-based RRAM devices, we demonstrate at least six resistance states with distinct memory margin and promising temporal variability. It is shown that the formation of small CFs with high density of oxygen vacancies enhances the uniformity of the switching characteristics in spite of the random nature of the switching effect. Insight into the origin of the gradual resistance modulation mechanisms is gained by the application of a trap-assisted-tunneling model together with numerical simulations of the filament formation physical processes.

Evaluating the Health Impact of Large-Scale Public Policy Changes: Classical and Novel Approaches

PubMed Central

Basu, Sanjay; Meghani, Ankita; Siddiqi, Arjumand

2018-01-01

Large-scale public policy changes are often recommended to improve public health. Despite varying widely—from tobacco taxes to poverty-relief programs—such policies present a common dilemma to public health researchers: how to evaluate their health effects when randomized controlled trials are not possible. Here, we review the state of knowledge and experience of public health researchers who rigorously evaluate the health consequences of large-scale public policy changes. We organize our discussion by detailing approaches to address three common challenges of conducting policy evaluations: distinguishing a policy effect from time trends in health outcomes or preexisting differences between policy-affected and -unaffected communities (using difference-in-differences approaches); constructing a comparison population when a policy affects a population for whom a well-matched comparator is not immediately available (using propensity score or synthetic control approaches); and addressing unobserved confounders by utilizing quasi-random variations in policy exposure (using regression discontinuity, instrumental variables, or near-far matching approaches). PMID:28384086

A Mock Randomized Controlled Trial With Audience Response Technology for Teaching and Learning Epidemiology.

PubMed

Baker, Philip R A; Francis, Daniel P; Cathcart, Abby

2017-04-01

The study's objective was to apply and assess an active learning approach to epidemiology and critical appraisal. Active learning comprised a mock, randomized controlled trial (RCT) conducted with learners in 3 countries. The mock trial consisted of blindly eating red Smarties candy (intervention) compared to yellow Smarties (control) to determine whether red Smarties increase happiness. Audience response devices were employed with the 3-fold purposes to produce outcome data for analysis of the effects of red Smarties, identify baseline and subsequent changes in participant's knowledge and confidence in understanding of RCTs, and assess the teaching approach. Of those attending, 82% (117 of 143 learners) participated in the trial component. Participating in the mock trial was a positive experience, and the use of the technology aided learning. The trial produced data that learners analyzed in "real time" during the class. The mock RCT is a fun and engaging approach to teaching RCTs and helping students to develop skills in critical appraisal.

Exploring the repetition bias in voluntary task switching.

PubMed

Mittelstädt, Victor; Dignath, David; Schmidt-Ott, Magdalena; Kiesel, Andrea

2018-01-01

In the voluntary task-switching paradigm, participants are required to randomly select tasks. We reasoned that the consistent finding of a repetition bias (i.e., participants repeat tasks more often than expected by chance) reflects reasonable adaptive task selection behavior to balance the goal of random task selection with the goals to minimize the time and effort for task performance. We conducted two experiments in which participants were provided with variable amount of preview for the non-chosen task stimuli (i.e., potential switch stimuli). We assumed that switch stimuli would initiate some pre-processing resulting in improved performance in switch trials. Results showed that reduced switch costs due to extra-preview in advance of each trial were accompanied by more task switches. This finding is in line with the characteristics of rational adaptive behavior. However, participants were not biased to switch tasks more often than chance despite large switch benefits. We suggest that participants might avoid effortful additional control processes that modulate the effects of preview on task performance and task choice.

Three-Dimensional Bayesian Geostatistical Aquifer Characterization at the Hanford 300 Area using Tracer Test Data

NASA Astrophysics Data System (ADS)

Chen, X.; Murakami, H.; Hahn, M. S.; Hammond, G. E.; Rockhold, M. L.; Rubin, Y.

2010-12-01

Tracer testing under natural or forced gradient flow provides useful information for characterizing subsurface properties, by monitoring and modeling the tracer plume migration in a heterogeneous aquifer. At the Hanford 300 Area, non-reactive tracer experiments, in addition to constant-rate injection tests and electromagnetic borehole flowmeter (EBF) profiling, were conducted to characterize the heterogeneous hydraulic conductivity field. A Bayesian data assimilation technique, method of anchored distributions (MAD), is applied to assimilate the experimental tracer test data and to infer the three-dimensional heterogeneous structure of the hydraulic conductivity in the saturated zone of the Hanford formation. In this study, the prior information of the underlying random hydraulic conductivity field was obtained from previous field characterization efforts using the constant-rate injection tests and the EBF data. The posterior distribution of the random field is obtained by further conditioning the field on the temporal moments of tracer breakthrough curves at various observation wells. The parallel three-dimensional flow and transport code PFLOTRAN is implemented to cope with the highly transient flow boundary conditions at the site and to meet the computational demand of the proposed method. The validation results show that the field conditioned on the tracer test data better reproduces the tracer transport behavior compared to the field characterized previously without the tracer test data. A synthetic study proves that the proposed method can effectively assimilate tracer test data to capture the essential spatial heterogeneity of the three-dimensional hydraulic conductivity field. These characterization results will improve conceptual models developed for the site, including reactive transport models. The study successfully demonstrates the capability of MAD to assimilate multi-scale multi-type field data within a consistent Bayesian framework. The MAD framework can potentially be applied to combine geophysical data with other types of data in site characterization.

Quasi-experimental study designs series-paper 2: complementary approaches to advancing global health knowledge.

PubMed

Geldsetzer, Pascal; Fawzi, Wafaie

2017-09-01

Quasi-experiments have been infrequently used in the health sciences. Focusing on health systems implementation research, this article details key advantages of quasi-experiments and argues that they can complement (but not replace) randomized evaluations. Specifically, it may be possible to use a quasi-experiment to study the causal effect of an intervention that cannot feasibly be randomized or that would be unethical (e.g., because the intervention has become the standard of care) to test in a randomized controlled trial (RCT). In addition, because they usually take advantage of routinely collected data, quasi-experiments may be feasible when it is too costly (either financially or in terms of the required time) to carry out a RCT - an important advantage in research on health systems, which vary widely between settings. Nonetheless, we argue that RCTs will continue to be indispensable for implementation research because i) the assumptions needed to establish causality with a quasi-experiment are often unverifiable, ii) available data frequently do not allow for a rigorous quasi-experiment, and iii) randomized designs tend to lend themselves more to informing policy makers of causal effects prior to (or during) the full-scale rollout of an intervention than quasi-experiments. Copyright © 2017 Elsevier Inc. All rights reserved.

Feature binding in visual short-term memory is unaffected by task-irrelevant changes of location, shape, and color.

PubMed

Logie, Robert H; Brockmole, James R; Jaswal, Snehlata

2011-01-01

Three experiments used a change detection paradigm across a range of study-test intervals to address the respective contributions of location, shape, and color to the formation of bindings of features in sensory memory and visual short-term memory (VSTM). In Experiment 1, location was designated task irrelevant and was randomized between study and test displays. The task was to detect changes in the bindings between shape and color. In Experiments 2 and 3, shape and color, respectively, were task irrelevant and randomized, with bindings tested between location and color (Experiment 2) and location and shape (Experiment 3). At shorter study-test intervals, randomizing location was most disruptive, followed by shape and then color. At longer intervals, randomizing any task-irrelevant feature had no impact on change detection for bindings between features, and location had no special role. Results suggest that location is crucial for initial perceptual binding but loses that special status once representations are formed in VSTM, which operates according to different principles, than do visual attention and perception.

Dimensions of Oppression in the Lives of Impoverished Black Women Who Use Drugs

PubMed Central

Windsor, Liliane Cambraia; Benoit, Ellen; Dunlap, Eloise

2010-01-01

Oppression against Black women continues to be a significant problem in the United States. The purpose of this study is to use grounded theory to identify multiple dimensions of oppression experienced by impoverished Black women who use drugs by examining several settings in which participants experience oppression. Three case studies of drug using, impoverished Black women were randomly selected from two large scale consecutive ethnographic studies conducted in New York City from 1998 to 2005. Analysis revealed five dimensions of oppression occurring within eight distinct settings. While dimensions constitute different manifestations of oppression, settings represented areas within participants’ lives or institutions with which participants interact. Dimensions of oppression included classism, sexism, familism, racism, and drugism. Settings included the school system, correction system, welfare system, housing and neighborhood, relationship with men, family, experiences with drug use, and employment. Findings have important implications for social justice, welfare, drug, and justice system policy. PMID:21113410

Partnerships for the Design, Conduct, and Analysis of Effectiveness, and Implementation Research: Experiences of the Prevention Science and Methodology Group

PubMed Central

Brown, C. Hendricks; Kellam, Sheppard G.; Kaupert, Sheila; Muthén, Bengt O.; Wang, Wei; Muthén, Linda K.; Chamberlain, Patricia; PoVey, Craig L.; Cady, Rick; Valente, Thomas W.; Ogihara, Mitsunori; Prado, Guillermo J.; Pantin, Hilda M.; Gallo, Carlos G.; Szapocznik, José; Czaja, Sara J.; McManus, John W.

2012-01-01

What progress prevention research has made comes through strategic partnerships with communities and institutions that host this research, as well as professional and practice networks that facilitate the diffusion of knowledge about prevention. We discuss partnership issues related to the design, analysis, and implementation of prevention research and especially how rigorous designs, including random assignment, get resolved through a partnership between community stakeholders, institutions, and researchers. These partnerships shape not only study design, but they determine the data that can be collected and how results and new methods are disseminated. We also examine a second type of partnership to improve the implementation of effective prevention programs into practice. We draw on social networks to studying partnership formation and function. The experience of the Prevention Science and Methodology Group, which itself is a networked partnership between scientists and methodologists, is highlighted. PMID:22160786

High-Intensity Radiated Field Fault-Injection Experiment for a Fault-Tolerant Distributed Communication System

NASA Technical Reports Server (NTRS)

Yates, Amy M.; Torres-Pomales, Wilfredo; Malekpour, Mahyar R.; Gonzalez, Oscar R.; Gray, W. Steven

2010-01-01

Safety-critical distributed flight control systems require robustness in the presence of faults. In general, these systems consist of a number of input/output (I/O) and computation nodes interacting through a fault-tolerant data communication system. The communication system transfers sensor data and control commands and can handle most faults under typical operating conditions. However, the performance of the closed-loop system can be adversely affected as a result of operating in harsh environments. In particular, High-Intensity Radiated Field (HIRF) environments have the potential to cause random fault manifestations in individual avionic components and to generate simultaneous system-wide communication faults that overwhelm existing fault management mechanisms. This paper presents the design of an experiment conducted at the NASA Langley Research Center's HIRF Laboratory to statistically characterize the faults that a HIRF environment can trigger on a single node of a distributed flight control system.

Partnerships for the design, conduct, and analysis of effectiveness, and implementation research: experiences of the prevention science and methodology group.

PubMed

Brown, C Hendricks; Kellam, Sheppard G; Kaupert, Sheila; Muthén, Bengt O; Wang, Wei; Muthén, Linda K; Chamberlain, Patricia; PoVey, Craig L; Cady, Rick; Valente, Thomas W; Ogihara, Mitsunori; Prado, Guillermo J; Pantin, Hilda M; Gallo, Carlos G; Szapocznik, José; Czaja, Sara J; McManus, John W

2012-07-01

What progress prevention research has made comes through strategic partnerships with communities and institutions that host this research, as well as professional and practice networks that facilitate the diffusion of knowledge about prevention. We discuss partnership issues related to the design, analysis, and implementation of prevention research and especially how rigorous designs, including random assignment, get resolved through a partnership between community stakeholders, institutions, and researchers. These partnerships shape not only study design, but they determine the data that can be collected and how results and new methods are disseminated. We also examine a second type of partnership to improve the implementation of effective prevention programs into practice. We draw on social networks to studying partnership formation and function. The experience of the Prevention Science and Methodology Group, which itself is a networked partnership between scientists and methodologists, is highlighted.

Linear Mixed Models: Gum and Beyond

NASA Astrophysics Data System (ADS)

Arendacká, Barbora; Täubner, Angelika; Eichstädt, Sascha; Bruns, Thomas; Elster, Clemens

2014-04-01

In Annex H.5, the Guide to the Evaluation of Uncertainty in Measurement (GUM) [1] recognizes the necessity to analyze certain types of experiments by applying random effects ANOVA models. These belong to the more general family of linear mixed models that we focus on in the current paper. Extending the short introduction provided by the GUM, our aim is to show that the more general, linear mixed models cover a wider range of situations occurring in practice and can be beneficial when employed in data analysis of long-term repeated experiments. Namely, we point out their potential as an aid in establishing an uncertainty budget and as means for gaining more insight into the measurement process. We also comment on computational issues and to make the explanations less abstract, we illustrate all the concepts with the help of a measurement campaign conducted in order to challenge the uncertainty budget in calibration of accelerometers.

Meta-analysis of randomized trials of percutaneous transluminal coronary angioplasty versus atherectomy, cutting balloon atherotomy, or laser angioplasty.

PubMed

Bittl, John A; Chew, Derek P; Topol, Eric J; Kong, David F; Califf, Robert M

2004-03-17

We conducted a systematic overview (meta-analysis) of randomized trials of balloon angioplasty versus coronary atherectomy, laser angioplasty, or cutting balloon atherotomy to evaluate the effects of plaque modification during percutaneous coronary intervention. Several mechanical approaches have been developed that ablate or section atheromatous plaque during percutaneous coronary interventions to optimize acute results, minimize intimal injury, and reduce complications and restenosis. Sixteen trials (9,222 patients) constitute the randomized controlled experience with atherectomy, laser, or atherotomy versus balloon angioplasty with or without coronary stenting. Each trial tested the hypothesis that ablative therapy would result in better clinical or angiographic results than balloon dilation alone. Short-term death rates (<31 days) were not improved by the use of ablative procedures (0.3% vs. 0.4%, odds ratio [OR] 0.94 [95% confidence interval 0.46 to 1.92]), but periprocedural myocardial infarctions (4.4% vs. 2.5%, OR 1.83 [95% CI 1.43 to 2.34]) and major adverse cardiac events (5.1% vs. 3.3%, OR 1.54 [95% CI 1.25 to 1.89]) were increased. Angiographic restenosis rates (6,958 patients) were not improved with the ablative devices (38.9% vs. 37.4%, OR 1.06 [95% CI 0.97 to 1.17]). No reduction in revascularization rates (25.2% vs. 24.5%, OR 1.04 [95% CI 0.94 to 1.14]) or cumulative adverse cardiac events rates up to one year after treatment were seen with ablative devices (27.8% vs. 26.1%, OR 1.09 [95% CI 0.99 to 1.20]). The combined experience from randomized trials suggests that ablative devices failed to achieve predefined clinical and angiographic outcomes. This meta-analysis does not support the hypothesis that routine ablation or sectioning of atheromatous tissue is beneficial during percutaneous coronary interventions.

Feeling the future: A meta-analysis of 90 experiments on the anomalous anticipation of random future events

PubMed Central

Bem, Daryl; Tressoldi, Patrizio; Rabeyron, Thomas; Duggan, Michael

2016-01-01

In 2011, one of the authors (DJB) published a report of nine experiments in the Journal of Personality and Social Psychology purporting to demonstrate that an individual’s cognitive and affective responses can be influenced by randomly selected stimulus events that do not occur until after his or her responses have already been made and recorded, a generalized variant of the phenomenon traditionally denoted by the term precognition. To encourage replications, all materials needed to conduct them were made available on request. We here report a meta-analysis of 90 experiments from 33 laboratories in 14 countries which yielded an overall effect greater than 6 sigma, z = 6.40, p = 1.2 × 10 -10  with an effect size (Hedges’ g) of 0.09. A Bayesian analysis yielded a Bayes Factor of 5.1 × 10 9, greatly exceeding the criterion value of 100 for “decisive evidence” in support of the experimental hypothesis. When DJB’s original experiments are excluded, the combined effect size for replications by independent investigators is 0.06, z = 4.16, p = 1.1 × 10 -5, and the BF value is 3,853, again exceeding the criterion for “decisive evidence.” The number of potentially unretrieved experiments required to reduce the overall effect size of the complete database to a trivial value of 0.01 is 544, and seven of eight additional statistical tests support the conclusion that the database is not significantly compromised by either selection bias or by intense “ p-hacking”—the selective suppression of findings or analyses that failed to yield statistical significance. P-curve analysis, a recently introduced statistical technique, estimates the true effect size of the experiments to be 0.20 for the complete database and 0.24 for the independent replications, virtually identical to the effect size of DJB’s original experiments (0.22) and the closely related “presentiment” experiments (0.21). We discuss the controversial status of precognition and other anomalous effects collectively known as psi. PMID:26834996

Antimonene: Experiments and theory of surface conductivity

NASA Astrophysics Data System (ADS)

Palacios, Juan Jose; Ares, Pablo; Pakdel, Sahar; Paz, Wendel; Zamora, Felix; Gomez-Herrero, Julio

Very recently antimony has been demonstrated to be amenable to standard exfoliation procedures opening the possibility of studying the electronic properties of isolated few-layers flakes of this material, a.k.a. antimonene. Antimony is a topological semimetal, meaning that its electronic structure presents spin-split helical states (or Dirac cones) on the surface, but it is still trivially metallic in bulk. Antimonene, on the other hand, may present a much reduced electronic bulk contribution for a small number of layers. A novel technique to make electrical contacts on the surface of individual thin flakes (5-10 monolayers) has allowed us to measure the (surface) conductivity of these in ambient conditions. Our measurements show a high conductivity in the range of 1 - 2e2 / h , which we attribute to the surface Dirac electrons. We have also carried out theoretical work to address the origin of this value, in particular, the importance of scattering between the Dirac electrons and the bulk bands. Our calculations are based on density functional theory for the electronic structure and Kubo formalism for the conductivity, the latter considering random disorder and the presence of water. Ministerio de Economia y Competitividad, Grant FIS2016-80434-P.

Classification of conductance traces with recurrent neural networks

NASA Astrophysics Data System (ADS)

Lauritzen, Kasper P.; Magyarkuti, András; Balogh, Zoltán; Halbritter, András; Solomon, Gemma C.

2018-02-01

We present a new automated method for structural classification of the traces obtained in break junction experiments. Using recurrent neural networks trained on the traces of minimal cross-sectional area in molecular dynamics simulations, we successfully separate the traces into two classes: point contact or nanowire. This is done without any assumptions about the expected features of each class. The trained neural network is applied to experimental break junction conductance traces, and it separates the classes as well as the previously used experimental methods. The effect of using partial conductance traces is explored, and we show that the method performs equally well using full or partial traces (as long as the trace just prior to breaking is included). When only the initial part of the trace is included, the results are still better than random chance. Finally, we show that the neural network classification method can be used to classify experimental conductance traces without using simulated results for training, but instead training the network on a few representative experimental traces. This offers a tool to recognize some characteristic motifs of the traces, which can be hard to find by simple data selection algorithms.

Effects of growth irradiance, nitrogen nutrition and watering regime on photosynthesis, leaf conductance and isoprene emission in leaves of Post Oak, Quercus stellata

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

Harley, P.; Archer, S.; Guenther, A.

1994-06-01

Seedlings of Post Oak (Quercus stellata), the dominant woody species of oak savannas of east-central Texas, were grown outside in College Station, TX from April to November 1993. Plants were randomly placed in one cell of a 3 [times] 2 [times] 2 factorial experiment, employing 3 nitrogen fertilization (25, 100 and 225 ppm NH[sub 4]NO[sub 23]), 2 light levels (70% and 20% of full sun) and 2 watering regimes (to maintain 80-100% or 30-50% of field capacity). In November, net photosynthesis, leaf conductance and leaf isoprene emission rates at 30[degrees]C and PPFD=1000 [mu]mol m[sup [minus]2]s[sup [minus]1] were determined for twomore » mature leaves on each of four plants from eight growth treatments and data were analyzed stastically. For plants grown under the lower watering regime, photosynthesis and isoprene emission increased with both increasing PPFD and nitrogen (effects significant at p<0.01). For plants grown at 70% full sun, effects of nitrogen treatment on photosynthesis, conductance and isoprene emission were significant (p<0.0001) while effects of watering treatment were not significant (p<0.2). Although watering treatment did not lead to significant differences between treatments, in a short-term drying experiment conducted on four plants, isoprene emissions increased through the drying period in previously well-watered plants, but decreased in previously droughted plants. Measurements were also made on two leaves to determine the effects of varying PPFD and temperature on rates of isoprene emission.« less

Can Principals Promote Teacher Development as Evaluators? A Case Study of Principals’ Views and Experiences

PubMed Central

Kraft, Matthew A.; Gilmour, Allison

2017-01-01

Purpose New teacher evaluation systems have expanded the role of principals as instructional leaders, but little is known about principals’ ability to promote teacher development through the evaluation process. We conducted a case study of principals’ perspectives on evaluation and their experiences implementing observation and feedback cycles to better understand whether principals feel as though they are able to promote teacher development as evaluators. Research Methods We conducted interviews with a stratified random sample of 24 principals in an urban district that recently implemented major reforms to its teacher evaluation system. We analyzed these interviews by drafting thematic summaries, coding interview transcripts, creating data-analytic matrices, and writing analytic memos. Findings We found that the evaluation reforms provided a common framework and language that helped facilitate principals’ feedback conversations with teachers. However, we also found that tasking principals with primary responsibility for conducting evaluations resulted in a variety of unintended consequences which undercut the quality of evaluation feedback they provided. We analyze five broad solutions to these challenges: strategically targeting evaluations, reducing operational responsibilities, providing principal training, hiring instructional coaches, and developing peer evaluation systems. Implications The quality of feedback teachers receive through the evaluation process depends critically on the time and training evaluators have to provide individualized and actionable feedback. Districts that task principals with primary responsibility for conducting observation and feedback cycles must attend to the many implementation challenges associated with this approach in order for next-generation evaluation systems to successfully promote teacher development. PMID:28729742

The effect of peer support on breast-feeding duration among primiparous women: a randomized controlled trial.

PubMed

Dennis, Cindy-Lee; Hodnett, Ellen; Gallop, Ruth; Chalmers, Beverley

2002-01-08

Most mothers stop breast-feeding before the recommended 6 months post partum. A systematic review showed that breast-feeding support programs by health care professionals did not substantially improve breast-feeding outcomes beyond 2 months post partum. We conducted a randomized controlled trial to evaluate the effect of peer (mother-to-mother) support on breast-feeding duration among first-time breast-feeding mothers. We recruited 256 breast-feeding mothers from 2 semi-urban community hospitals near Toronto and randomly assigned them to a control group (conventional care) or a peer support group (conventional care plus telephone-based support, initiated within 48 hours after hospital discharge, from a woman experienced with breast-feeding who attended a 2.5-hour orientation session). Follow-up of breast-feeding duration, maternal satisfaction with infant feeding method and perceptions of peer support received was conducted at 4, 8 and 12 weeks post partum. Significantly more mothers in the peer support group than in the control group continued to breast-feed at 3 months post partum (81.1% v. 66.9%, p = 0.01) and did so exclusively (56.8% v. 40.3%, p = 0.01). Breast-feeding rates at 4, 8 and 12 weeks post partum were 92.4%, 84.8% and 81.1% respectively among the mothers in the peer support group, as compared with 83.9%, 75.0% and 66.9% among those in the control group (p < or = 0.05 for all time periods). The corresponding relative risks were 1.10 (95% confidence interval [CI] 1.01-2.72) at 4 weeks, 1.13 (95% CI 1.00-1.28) at 8 weeks and 1.21 (95% CI 1.04-1.41) at 12 weeks post partum. In addition, when asked for an overall rating of their feeding experience, significantly fewer mothers in the peer support group than in the control group were dissatisfied (1.5% v. 10.5%) (p = 0.02). Of the 130 mothers who evaluated the peer support intervention, 81.6% were satisfied with their peer volunteer experience and 100% felt that all new breast-feeding mothers should be offered this peer support intervention. The telephone-based peer support intervention was effective in maintaining breast-feeding to 3 months post partum and improving satisfaction with the infant feeding experience. The high satisfaction with and acceptance of the intervention indicates that breast-feeding peer support programs, in conjunction with professional health services, are effective.

The effect of peer support on breast-feeding duration among primiparous women: a randomized controlled trial

PubMed Central

Dennis, Cindy-Lee; Hodnett, Ellen; Gallop, Ruth; Chalmers, Beverley

2002-01-01

Background Most mothers stop breast-feeding before the recommended 6 months post partum. A systematic review showed that breast-feeding support programs by health care professionals did not substantially improve breast-feeding outcomes beyond 2 months post partum. We conducted a randomized controlled trial to evaluate the effect of peer (mother-to-mother) support on breast-feeding duration among first-time breast-feeding mothers. Methods We recruited 256 breast-feeding mothers from 2 semi-urban community hospitals near Toronto and randomly assigned them to a control group (conventional care) or a peer support group (conventional care plus telephone-based support, initiated within 48 hours after hospital discharge, from a woman experienced with breast-feeding who attended a 2.5-hour orientation session). Follow-up of breast-feeding duration, maternal satisfaction with infant feeding method and perceptions of peer support received was conducted at 4, 8 and 12 weeks post partum. Results Significantly more mothers in the peer support group than in the control group continued to breast-feed at 3 months post partum (81.1% v. 66.9%, p = 0.01) and did so exclusively (56.8% v. 40.3%, p = 0.01). Breast-feeding rates at 4, 8 and 12 weeks post partum were 92.4%, 84.8% and 81.1% respectively among the mothers in the peer support group, as compared with 83.9%, 75.0% and 66.9% among those in the control group (p ≤ 0.05 for all time periods). The corresponding relative risks were 1.10 (95% confidence interval [CI] 1.01–2.72) at 4 weeks, 1.13 (95% CI 1.00–1.28) at 8 weeks and 1.21 (95% CI 1.04–1.41) at 12 weeks post partum. In addition, when asked for an overall rating of their feeding experience, significantly fewer mothers in the peer support group than in the control group were dissatisfied (1.5% v. 10.5%) (p = 0.02). Of the 130 mothers who evaluated the peer support intervention, 81.6% were satisfied with their peer volunteer experience and 100% felt that all new breast-feeding mothers should be offered this peer support intervention. Interpretation The telephone-based peer support intervention was effective in maintaining breast-feeding to 3 months post partum and improving satisfaction with the infant feeding experience. The high satisfaction with and acceptance of the intervention indicates that breast-feeding peer support programs, in conjunction with professional health services, are effective. PMID:11800243

Stress lowers the detection threshold for foul-smelling 2-mercaptoethanol.

PubMed

Pacharra, Marlene; Schäper, Michael; Kleinbeck, Stefan; Blaszkewicz, Meinolf; Wolf, Oliver T; van Thriel, Christoph

2016-01-01

Previous studies have reported enhanced vigilance for threat-related information in response to acute stress. While it is known that acute stress modulates sensory systems in humans, its impact on olfaction and the olfactory detection of potential threats is less clear. Two psychophysical experiments examined, if acute stress lowers the detection threshold for foul-smelling 2-mercaptoethanol. Participants in Experiment 1 (N = 30) and Experiment 2 (N = 32) were randomly allocated to a control group or a stress group. Participants in the stress group underwent a purely psychosocial stressor (public mental arithmetic) in Experiment 1 and a stressor that combined a physically demanding task with social-evaluative threat in Experiment 2 (socially evaluated cold-pressor test). In both experiments, olfactory detection thresholds were repeatedly assessed by means of dynamic dilution olfactometry. Each threshold measurement consisted of three trials conducted using an ascending method of limits. Participants in the stress groups showed the expected changes in heart rate, salivary cortisol, and mood measures in response to stress. About 20 min after the stressor, participants in the stress groups could detect 2-mercaptoethanol at a lower concentration than participants in the corresponding control groups. Our results show that acute stress lowers the detection threshold for a malodor.

Experimental demonstration of an active phase randomization and monitor module for quantum key distribution

NASA Astrophysics Data System (ADS)

Sun, Shi-Hai; Liang, Lin-Mei

2012-08-01

Phase randomization is a very important assumption in the BB84 quantum key distribution (QKD) system with weak coherent source; otherwise, eavesdropper may spy the final key. In this Letter, a stable and monitored active phase randomization scheme for the one-way and two-way QKD system is proposed and demonstrated in experiments. Furthermore, our scheme gives an easy way for Alice to monitor the degree of randomization in experiments. Therefore, we expect our scheme to become a standard part in future QKD systems due to its secure significance and feasibility.

Feasibility of Conducting a Randomized Trial to Promote Healthy Eating, Active Play and Sustainability Awareness in Early Childhood Curricula

ERIC Educational Resources Information Center

Morris, Heather; Skouteris, Helen; Edwards, Susan; Rutherford, Leonie Margaret; Cutter-Mackenzie, Amy; O'Connor, Amanda; Mantilla, Ana; Huang, Terry TK; Lording, Kate Marion; Williams-Smith, Janet

2016-01-01

We sought to evaluate the feasibility of conducting a randomized trial to evaluate the efficacy of a preschool/kindergarten curriculum intervention designed to increase 4-year-old children's knowledge of healthy eating, active play and the sustainability consequences of their food and toy choices. Ninety intervention and 65 control parent/child…

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

Effects of online games on student performance in undergraduate physics

NASA Astrophysics Data System (ADS)

Sadiq, Irfan

The present state of physics teaching and learning is a reflection of the difficulty of the subject matter which has resulted in students' low motivation toward physics as well as lack of meaningful and deeper learning experiences. In light of an overall decline in interest in physics, an investigation of alternate teaching and learning methods and tools was appropriate. The research posed the following question: To what extent do online games about kinematics and two-dimensional motion impact student performance in undergraduate general physics as measured by a unit posttest? Two intact classes of 20 students each were randomly assigned to either the experimental group or the control group. Only the experimental group received the treatment of using online games. The duration of topics covered in the game content was identical to the lecture on kinematics and two-dimensional motion. Instructors for the experimental group incorporated online games in their regular classroom teaching, whereas those in the control group continued with their previously used curriculum without games. This study was conducted in three weekly sessions. Although students were not selected using random sampling, existing classes were randomly assigned to either the experimental group or the control group. There were 20 students in the experimental group and 20 students in the control group. The independent samples t test was conducted to compare the means of two independently sampled experimental and control groups. Analysis of covariance (ANCOVA) was used to determine if the two groups were significantly different with regard to their general physics performance on the posttest while controlling for the pretest scores. Analysis of posttest and pretest scores revealed that game-based learning did not significantly impact student performance.

Chocolate and Prevention of Cardiovascular Disease: A Systematic Review

PubMed Central

Ding, Eric L; Hutfless, Susan M; Ding, Xin; Girotra, Saket

2006-01-01

Background Consumption of chocolate has been often hypothesized to reduce the risk of cardiovascular disease (CVD) due to chocolate's high levels of stearic acid and antioxidant flavonoids. However, debate still lingers regarding the true long term beneficial cardiovascular effects of chocolate overall. Methods We reviewed English-language MEDLINE publications from 1966 through January 2005 for experimental, observational, and clinical studies of relations between cocoa, cacao, chocolate, stearic acid, flavonoids (including flavonols, flavanols, catechins, epicatechins, and procynadins) and the risk of cardiovascular disease (coronary heart disease (CHD), stroke). A total of 136 publications were selected based on relevance, and quality of design and methods. An updated meta-analysis of flavonoid intake and CHD mortality was also conducted. Results The body of short-term randomized feeding trials suggests cocoa and chocolate may exert beneficial effects on cardiovascular risk via effects on lowering blood pressure, anti-inflammation, anti-platelet function, higher HDL, decreased LDL oxidation. Additionally, a large body of trials of stearic acid suggests it is indeed cholesterol-neutral. However, epidemiologic studies of serum and dietary stearic acid are inconclusive due to many methodologic limitations. Meanwhile, the large body of prospective studies of flavonoids suggests the flavonoid content of chocolate may reduce risk of cardiovascular mortality. Our updated meta-analysis indicates that intake of flavonoids may lower risk of CHD mortality, RR = 0.81 (95% CI: 0.71–0.92) comparing highest and lowest tertiles. Conclusion Multiple lines of evidence from laboratory experiments and randomized trials suggest stearic acid may be neutral, while flavonoids are likely protective against CHD mortality. The highest priority now is to conduct larger randomized trials to definitively investigate the impact of chocolate consumption on long-term cardiovascular outcomes. PMID:16390538

Chocolate and prevention of cardiovascular disease: a systematic review.

PubMed

Ding, Eric L; Hutfless, Susan M; Ding, Xin; Girotra, Saket

2006-01-03

Consumption of chocolate has been often hypothesized to reduce the risk of cardiovascular disease (CVD) due to chocolate's high levels of stearic acid and antioxidant flavonoids. However, debate still lingers regarding the true long term beneficial cardiovascular effects of chocolate overall. We reviewed English-language MEDLINE publications from 1966 through January 2005 for experimental, observational, and clinical studies of relations between cocoa, cacao, chocolate, stearic acid, flavonoids (including flavonols, flavanols, catechins, epicatechins, and procynadins) and the risk of cardiovascular disease (coronary heart disease (CHD), stroke). A total of 136 publications were selected based on relevance, and quality of design and methods. An updated meta-analysis of flavonoid intake and CHD mortality was also conducted. The body of short-term randomized feeding trials suggests cocoa and chocolate may exert beneficial effects on cardiovascular risk via effects on lowering blood pressure, anti-inflammation, anti-platelet function, higher HDL, decreased LDL oxidation. Additionally, a large body of trials of stearic acid suggests it is indeed cholesterol-neutral. However, epidemiologic studies of serum and dietary stearic acid are inconclusive due to many methodologic limitations. Meanwhile, the large body of prospective studies of flavonoids suggests the flavonoid content of chocolate may reduce risk of cardiovascular mortality. Our updated meta-analysis indicates that intake of flavonoids may lower risk of CHD mortality, RR = 0.81 (95% CI: 0.71-0.92) comparing highest and lowest tertiles. Multiple lines of evidence from laboratory experiments and randomized trials suggest stearic acid may be neutral, while flavonoids are likely protective against CHD mortality. The highest priority now is to conduct larger randomized trials to definitively investigate the impact of chocolate consumption on long-term cardiovascular outcomes.

Trauma and recent life events in individuals at ultra high risk for psychosis: review and meta-analysis.

PubMed

Kraan, Tamar; Velthorst, Eva; Smit, Filip; de Haan, Lieuwe; van der Gaag, Mark

2015-02-01

Childhood trauma and recent life-events have been related to psychotic disorders. The aim of the present study was to examine whether childhood trauma and recent life-events are significantly more prevalent in patients at Ultra High Risk (UHR) of developing a psychotic disorder compared to healthy controls. A search of PsychInfo and Embase was conducted, relevant papers were reviewed, and three random-effects meta-analyses were performed. One meta-analysis assessed the prevalence rate of childhood trauma in UHR subjects and two meta-analyses were conducted to compare UHR subjects and healthy control subjects on the experience of childhood trauma and recent life-events. We found 12 studies on the prevalence of (childhood) trauma in UHR populations and 4 studies on recent life-events in UHR populations. We performed a meta-analysis on 6 studies (of which trauma prevalence rates were available) on childhood trauma in UHR populations, yielding a mean prevalence rate of 86.8% (95% CI 77%-93%). Childhood trauma was significantly more prevalent in UHR subjects compared to healthy control groups (Random effects Hedges' g=1.09; Z=4.60, p<.001). In contrast to our hypothesis, life-event rates were significantly lower in UHR subjects compared to healthy controls (Random effects Hedges' g=-0.53; Z=-2.36, p<.02). Our meta-analytic results illustrate that childhood trauma is highly prevalent among UHR subjects and that childhood trauma is related to UHR status. These results are in line with studies on childhood trauma in psychotic populations. In contrast to studies on recent life-events in psychotic populations, our results show that recent life-events are not associated with UHR status. Copyright © 2014 Elsevier B.V. All rights reserved.

Care coordination experiences of people with disabilities enrolled in medicaid managed care.

PubMed

Bowers, Anne; Owen, Randall; Heller, Tamar

2017-10-01

To understand the impact of experience and contacts with care coordinators on Medicaid Managed Care (MMC) enrollees with disabilities. Primary data was collected from a random sample of 6000 out of the 100,000 people with disabilities enrolled in one state's mandatory MMC program. Surveys were conducted through the mail, telephone, and Internet; 1041 surveys were completed. The sample used for analysis included 442 MMC enrollees who received care coordination. Regression analyses were conducted with the outcomes of number of unmet health care needs and enrollee appraisal of the health services they received. Race, age, gender, and disability variables controlled for demographic differences, and the independent variables included enrollee experience with a care coordinator (coordinator knowledge of enrollee medical history and whether the coordinator took into account enrollee wishes and input) and frequency of contact with a care coordinator. Positive enrollee experiences with care coordinators significantly related to more positive enrollee health service appraisals and fewer unmet health care needs; frequency of contact did not have any significant impacts. People with mental health disabilities and intellectual/developmental disabilities had significantly lower health service appraisals. People with mental health disabilities had significantly more unmet needs. Quality of care coordination, but not frequency of contact alone, is associated with better health outcomes for MMC enrollees. Implications for rehabilitation Care coordination is a core component of managed care and facilitates effective healthcare management for people with complex chronic conditions and disabilities. Better experiences with care coordinators is related to fewer unmet healthcare needs and more positive health care service appraisals for Medicaid managed care enrollees. The continuous development of person-centered care coordination strategies and training programs emphasizing quality relationships between coordinators and consumers should be prioritized.

Efficient experimental design for uncertainty reduction in gene regulatory networks.

PubMed

Dehghannasiri, Roozbeh; Yoon, Byung-Jun; Dougherty, Edward R

2015-01-01

An accurate understanding of interactions among genes plays a major role in developing therapeutic intervention methods. Gene regulatory networks often contain a significant amount of uncertainty. The process of prioritizing biological experiments to reduce the uncertainty of gene regulatory networks is called experimental design. Under such a strategy, the experiments with high priority are suggested to be conducted first. The authors have already proposed an optimal experimental design method based upon the objective for modeling gene regulatory networks, such as deriving therapeutic interventions. The experimental design method utilizes the concept of mean objective cost of uncertainty (MOCU). MOCU quantifies the expected increase of cost resulting from uncertainty. The optimal experiment to be conducted first is the one which leads to the minimum expected remaining MOCU subsequent to the experiment. In the process, one must find the optimal intervention for every gene regulatory network compatible with the prior knowledge, which can be prohibitively expensive when the size of the network is large. In this paper, we propose a computationally efficient experimental design method. This method incorporates a network reduction scheme by introducing a novel cost function that takes into account the disruption in the ranking of potential experiments. We then estimate the approximate expected remaining MOCU at a lower computational cost using the reduced networks. Simulation results based on synthetic and real gene regulatory networks show that the proposed approximate method has close performance to that of the optimal method but at lower computational cost. The proposed approximate method also outperforms the random selection policy significantly. A MATLAB software implementing the proposed experimental design method is available at http://gsp.tamu.edu/Publications/supplementary/roozbeh15a/.

Efficient experimental design for uncertainty reduction in gene regulatory networks

PubMed Central

2015-01-01

Background An accurate understanding of interactions among genes plays a major role in developing therapeutic intervention methods. Gene regulatory networks often contain a significant amount of uncertainty. The process of prioritizing biological experiments to reduce the uncertainty of gene regulatory networks is called experimental design. Under such a strategy, the experiments with high priority are suggested to be conducted first. Results The authors have already proposed an optimal experimental design method based upon the objective for modeling gene regulatory networks, such as deriving therapeutic interventions. The experimental design method utilizes the concept of mean objective cost of uncertainty (MOCU). MOCU quantifies the expected increase of cost resulting from uncertainty. The optimal experiment to be conducted first is the one which leads to the minimum expected remaining MOCU subsequent to the experiment. In the process, one must find the optimal intervention for every gene regulatory network compatible with the prior knowledge, which can be prohibitively expensive when the size of the network is large. In this paper, we propose a computationally efficient experimental design method. This method incorporates a network reduction scheme by introducing a novel cost function that takes into account the disruption in the ranking of potential experiments. We then estimate the approximate expected remaining MOCU at a lower computational cost using the reduced networks. Conclusions Simulation results based on synthetic and real gene regulatory networks show that the proposed approximate method has close performance to that of the optimal method but at lower computational cost. The proposed approximate method also outperforms the random selection policy significantly. A MATLAB software implementing the proposed experimental design method is available at http://gsp.tamu.edu/Publications/supplementary/roozbeh15a/. PMID:26423515

Threats to validity in the design and conduct of preclinical efficacy studies: a systematic review of guidelines for in vivo animal experiments.

PubMed

Henderson, Valerie C; Kimmelman, Jonathan; Fergusson, Dean; Grimshaw, Jeremy M; Hackam, Dan G

2013-01-01

The vast majority of medical interventions introduced into clinical development prove unsafe or ineffective. One prominent explanation for the dismal success rate is flawed preclinical research. We conducted a systematic review of preclinical research guidelines and organized recommendations according to the type of validity threat (internal, construct, or external) or programmatic research activity they primarily address. We searched MEDLINE, Google Scholar, Google, and the EQUATOR Network website for all preclinical guideline documents published up to April 9, 2013 that addressed the design and conduct of in vivo animal experiments aimed at supporting clinical translation. To be eligible, documents had to provide guidance on the design or execution of preclinical animal experiments and represent the aggregated consensus of four or more investigators. Data from included guidelines were independently extracted by two individuals for discrete recommendations on the design and implementation of preclinical efficacy studies. These recommendations were then organized according to the type of validity threat they addressed. A total of 2,029 citations were identified through our search strategy. From these, we identified 26 guidelines that met our eligibility criteria--most of which were directed at neurological or cerebrovascular drug development. Together, these guidelines offered 55 different recommendations. Some of the most common recommendations included performance of a power calculation to determine sample size, randomized treatment allocation, and characterization of disease phenotype in the animal model prior to experimentation. By identifying the most recurrent recommendations among preclinical guidelines, we provide a starting point for developing preclinical guidelines in other disease domains. We also provide a basis for the study and evaluation of preclinical research practice. Please see later in the article for the Editors' Summary.

Investigation on the accuracy and reliability of in-situ stress measurements using hydraulic fracturing in perforated cased holes

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

Warpinski, N.R.

At present, the only viable technique for accurately measuring stresses at depth in a borehole is hydraulic fracturing. These have been termed microfracs because very small amounts of fluid are injected at low flow rates into the formation. When the well is shut in, the pressure immediately drops from the injection pressure to the instantaneous shut-in pressure (ISIP) which is approximately equal to sigma/sub min/. In general, the ISIP can be measured quite accurately in open holes. For most oil and gas applications, however, it is impossible or impractical to conduct these tests in an open-hole environment. The effects ofmore » the casing, cement annulus, explosive perforation damage, and random performation orientation are impossible to predict theoretically, and laboratory tests are usually conducted under nonrealistic conditions. A set of in situ experiments was conducted to evaluate the accuracy and reliability of this technique, to aid in the selection of an optimum perforation schedule, and to develop a diagnostic capability from the pressure response.« less

Dual nature of localization in guiding systems with randomly corrugated boundaries: Anderson-type versus entropic

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

Tarasov, Yu.V., E-mail: yutarasov@ire.kharkov.ua; Shostenko, L.D.

A unified theory for the conductance of an infinitely long multimode quantum wire whose finite segment has randomly rough lateral boundaries is developed. It enables one to rigorously take account of all feasible mechanisms of wave scattering, both related to boundary roughness and to contacts between the wire rough section and the perfect leads within the same technical frameworks. The rough part of the conducting wire is shown to act as a mode-specific randomly modulated effective potential barrier whose height is governed essentially by the asperity slope. The mean height of the barrier, which is proportional to the average slopemore » squared, specifies the number of conducting channels. Under relatively small asperity amplitude this number can take on arbitrary small, up to zero, values if the asperities are sufficiently sharp. The consecutive channel cut-off that arises when the asperity sharpness increases can be regarded as a kind of localization, which is not related to the disorder per se but rather is of entropic or (equivalently) geometric origin. The fluctuating part of the effective barrier results in two fundamentally different types of guided wave scattering, viz., inter- and intramode scattering. The intermode scattering is shown to be for the most part very strong except in the cases of (a) extremely smooth asperities, (b) excessively small length of the corrugated segment, and (c) the asperities sharp enough for only one conducting channel to remain in the wire. Under strong intermode scattering, a new set of conducting channels develops in the corrugated waveguide, which have the form of asymptotically decoupled extended modes subject to individual solely intramode random potentials. In view of this fact, two transport regimes only are realizable in randomly corrugated multimode waveguides, specifically, the ballistic and the localized regime, the latter characteristic of one-dimensional random systems. Two kinds of localization are thus shown to coexist in waveguide-like systems with randomly corrugated boundaries, specifically, the entropic localization and the one-dimensional Anderson (disorder-driven) localization. If the particular mode propagates across the rough segment ballistically, the Fabry–Pérot-type oscillations should be observed in the conductance, which are suppressed for the mode transferred in the Anderson-localized regime.« less

A qualitative exploration of the experiences of patients with breast cancer receiving outpatient-based chemotherapy.

PubMed

Lai, Xiao Bin; Ching, Shirley Siu Yin; Wong, Frances Kam Yuet

2017-10-01

The aim of this study was to understand the experiences of patients with breast cancer and their involvement during outpatient-based chemotherapy in Hong Kong. The outcome evaluation using a mixed-methods approach is not common in interventional studies of nurse-led chemotherapy care programmes. A qualitative approach could provide a deep understanding of the experiences of patients. A qualitative study was conducted. This is part of a randomized controlled trial of a nurse-led care programme (NCT02228200). Individual interviews were conducted in 2013 with 10 patients with breast cancer after they had completed the chemotherapy. Qualitative content analysis was adopted to analyse the interviews. Chemotherapy affected the patients in different ways. Some participants completed the chemotherapy treatment smoothly with minimum side effects, while others encountered many problems during the treatment, which had a great impact on their lives. Guided by their coping attitudes, which were affected by the Chinese culture, most participants adopted behavioural, social, cognitive and emotional strategies to actively cope with the chemotherapy. A few tolerated the treatment passively. Some thought that the process of undergoing chemotherapy was physically bearable, while some equated it with suffering. Others regarded it as a chance to get a new start. The experience of patients with breast cancer during chemotherapy can be likened to that of going on a hike. They reach the peak through different paths and bear different burdens. Yet, they have to go through until the end, regardless of how much of a burden they bear and how they achieve the peak. © 2017 John Wiley & Sons Ltd.

Unscented Kalman filter assimilation of time-lapse self-potential data for monitoring solute transport

NASA Astrophysics Data System (ADS)

Cui, Yi-an; Liu, Lanbo; Zhu, Xiaoxiong

2017-08-01

Monitoring the extent and evolution of contaminant plumes in local and regional groundwater systems from existing landfills is critical in contamination control and remediation. The self-potential survey is an efficient and economical nondestructive geophysical technique that can be used to investigate underground contaminant plumes. Based on the unscented transform, we have built a Kalman filtering cycle to conduct time-lapse data assimilation for monitoring the transport of solute based on the solute transport experiment using a bench-scale physical model. The data assimilation was formed by modeling the evolution based on the random walk model and observation correcting based on the self-potential forward. Thus, monitoring self-potential data can be inverted by the data assimilation technique. As a result, we can reconstruct the dynamic process of the contaminant plume instead of using traditional frame-to-frame static inversion, which may cause inversion artifacts. The data assimilation inversion algorithm was evaluated through noise-added synthetic time-lapse self-potential data. The result of the numerical experiment shows validity, accuracy and tolerance to the noise of the dynamic inversion. To validate the proposed algorithm, we conducted a scaled-down sandbox self-potential observation experiment to generate time-lapse data that closely mimics the real-world contaminant monitoring setup. The results of physical experiments support the idea that the data assimilation method is a potentially useful approach for characterizing the transport of contamination plumes using the unscented Kalman filter (UKF) data assimilation technique applied to field time-lapse self-potential data.

Robust random telegraph conductivity noise in single crystals of the ferromagnetic insulating manganite La0.86Ca0.14MnO3

NASA Astrophysics Data System (ADS)

Przybytek, J.; Fink-Finowicki, J.; Puźniak, R.; Shames, A.; Markovich, V.; Mogilyansky, D.; Jung, G.

2017-03-01

Robust random telegraph conductivity fluctuations have been observed in La0.86Ca0.14MnO3 manganite single crystals. At room temperatures, the spectra of conductivity fluctuations are featureless and follow a 1 /f shape in the entire experimental frequency and bias range. Upon lowering the temperature, clear Lorentzian bias-dependent excess noise appears on the 1 /f background and eventually dominates the spectral behavior. In the time domain, fully developed Lorentzian noise appears as pronounced two-level random telegraph noise with a thermally activated switching rate, which does not depend on bias current and applied magnetic field. The telegraph noise is very robust and persists in the exceptionally wide temperature range of more than 50 K. The amplitude of the telegraph noise decreases exponentially with increasing bias current in exactly the same manner as the sample resistance increases with the current, pointing out the dynamic current redistribution between percolation paths dominated by phase-separated clusters with different conductivity as a possible origin of two-level conductivity fluctuations.

Effects of zinc supplementation on subscales of anorexia in children: A randomized controlled trial.

PubMed

Khademian, Majid; Farhangpajouh, Neda; Shahsanaee, Armindokht; Bahreynian, Maryam; Mirshamsi, Mehran; Kelishadi, Roya

2014-01-01

This study aims to assess the effects of zinc supplementation on improving the appetite and its subscales in children. This study was conducted in 2013 in Isfahan, Iran. It had two phases. At the first step, after validation of the Child Eating Behaviour Questionaire (CEBQ), it was completed for 300 preschool children, who were randomly selected. The second phase was conducted as a randomized controlled trial. Eighty of these children were randomly selected, and were randomly assigned to two groups of equal number receiving zinc (10 mg/day) or placebo for 12 weeks. Overall 77 children completed the trial (39 in the case and 3 in the control group).The results showed that zinc supplement can improve calorie intake in children by affecting some CEBQ subscales like Emotional over Eating and Food Responsible. Zinc supplementation had positive impact in promoting the calorie intake and some subscales of anorexia.

Intraclass Correlation Values for Planning Group-Randomized Trials in Education

ERIC Educational Resources Information Center

Hedges, Larry V.; Hedberg, E. C.

2007-01-01

Experiments that assign intact groups to treatment conditions are increasingly common in social research. In educational research, the groups assigned are often schools. The design of group-randomized experiments requires knowledge of the intraclass correlation structure to compute statistical power and sample sizes required to achieve adequate…

Frequency of Examinations and Student Achievement in a Randomized Experiment

ERIC Educational Resources Information Center

De Paola, Maria; Scoppa, Vincenzo

2011-01-01

We carry out a randomized experiment involving undergraduate students enrolled at an Italian University attending two introductory economics classes to evaluate the impact on achievement of examination frequency and interim feedback provision. Students in the treated group were allowed to undertake an intermediate exam and were informed about the…

Randomized Controlled Studies and Alternative Designs in Outcome Studies: Challenges and Opportunities

ERIC Educational Resources Information Center

Shadish, William R.

2011-01-01

This article reviews several decades of the author's meta-analytic and experimental research on the conditions under which nonrandomized experiments can approximate the results from randomized experiments (REs). Several studies make clear that we can expect accurate effect estimates from the regression discontinuity design, though its statistical…

RANDOMIZATION PROCEDURES FOR THE ANALYSIS OF EDUCATIONAL EXPERIMENTS.

ERIC Educational Resources Information Center

COLLIER, RAYMOND O.

CERTAIN SPECIFIC ASPECTS OF HYPOTHESIS TESTS USED FOR ANALYSIS OF RESULTS IN RANDOMIZED EXPERIMENTS WERE STUDIED--(1) THE DEVELOPMENT OF THE THEORETICAL FACTOR, THAT OF PROVIDING INFORMATION ON STATISTICAL TESTS FOR CERTAIN EXPERIMENTAL DESIGNS AND (2) THE DEVELOPMENT OF THE APPLIED ELEMENT, THAT OF SUPPLYING THE EXPERIMENTER WITH MACHINERY FOR…

A New In Vitro Co-Culture Model Using Magnetic Force-Based Nanotechnology.

PubMed

Takanari, Hiroki; Miwa, Keiko; Fu, XianMing; Nakai, Junichi; Ito, Akira; Ino, Kousuke; Honda, Hiroyuki; Tonomura, Wataru; Konishi, Satoshi; Opthof, Tobias; van der Heyden, Marcel Ag; Kodama, Itsuo; Lee, Jong-Kook

2016-10-01

Skeletal myoblast (SkMB) transplantation has been conducted as a therapeutic strategy for severe heart failure. However, arrhythmogenicity following transplantation remains unsolved. We developed an in vitro model of myoblast transplantation with "patterned" or "randomly-mixed" co-culture of SkMBs and cardiomyocytes enabling subsequent electrophysiological, and arrhythmogenic evaluation. SkMBs were magnetically labeled with magnetite nanoparticles and co-cultured with neonatal rat ventricular myocytes (NRVMs) on multi-electrode arrays. SkMBs were patterned by a magnet beneath the arrays. Excitation synchronicity was evaluated by Ca(2+) imaging using a gene-encoded Ca(2+) indicator, G-CaMP2. In the monoculture of NRVMs (control), conduction was well-organized. In the randomly-mixed co-culture of NRVMs and SkMBs (random group), there was inhomogeneous conduction from multiple origins. In the "patterned" co-culture where an en bloc SKMB-layer was inserted into the NRVM-layer, excitation homogenously propagated although conduction was distorted by the SkMB-area. The 4-mm distance conduction time (CT) in the random group was significantly longer (197 ± 126 ms) than in control (17 ± 3 ms). In the patterned group, CT through NRVM-area did not change (25 ± 3 ms), although CT through the SkMB-area was significantly longer (132 ± 77 ms). The intervals between spontaneous excitation varied beat-to-beat in the random group, while regular beating was recorded in the control and patterned groups. Synchronized Ca(2+) transients of NRVMs were observed in the patterned group, whereas those in the random group were asynchronous. Patterned alignment of SkMBs is feasible with magnetic nanoparticles. Using the novel in vitro model mimicking cell transplantation, it may become possible to predict arrhythmogenicity due to heterogenous cell transplantation. J. Cell. Physiol. 231: 2249-2256, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Who Benefits and How Does It Work? Moderators and Mediators of Outcome in an Effectiveness Trial of a Parenting Intervention

ERIC Educational Resources Information Center

Gardner, Frances; Hutchings, Judy; Bywater, Tracey; Whitaker, Chris

2010-01-01

We examined mediators and moderators of change in conduct problems, in a multiagency randomized trial of the Incredible Years parenting program. Preschoolers (n = 153) at risk for conduct problems were randomly assigned to intervention (n = 104) and wait-list (n = 49) groups. Boys and younger children, and those with more depressed mothers, tended…

The best marketing strategy in aesthetic plastic surgery: evaluating patients' preferences by conjoint analysis.

PubMed

Marsidi, Nick; van den Bergh, Maurice W H M; Luijendijk, Roland W

2014-01-01

To provide the best marketing strategy for a private clinic, knowledge of patients' preferences is essential. In marketing, conjoint analysis has been frequently used to calculate which attributes of a product are most valuable to consumers. This study investigates the relative importance of attributes that influence the selection and decision-making process when choosing an aesthetic private clinic, using conjoint analysis. The following attributes were chosen by the senior author (R.W.L.) and a marketing and communications director after a preselection of 25 randomly selected people: relative cost of the procedure, travel time, experience of the plastic surgeon, size of the clinic, method of referral, and online presentation. The attributes were then divided into levels. Using a random factor conducted by SPSS, 18 different scenarios were created and rated online by 150 potential patients before their potential visit or consultation. The patients could rate these scenarios on a scale from 1 to 7 with respect to the likeliness of visiting the clinic. The most important attribute was experience of the surgeon (35.6 percent), followed by method of referral (21.5 percent), travel time (14.2 percent), cost of procedure (12.9 percent), online presentation (9.7 percent), and size of the clinic (6.1 percent). Six of 16 levels gave a negative influence on the decision making. The authors' study shows that the two most important attributes are the experience of the surgeon and the method of referral and that conjoint analysis is effective in determining patients' preferences. It also shows which levels positively or negatively contribute per attribute.

[From Nebuchadnezzar to the randomized controlled trial--milestones in the development of clinical research].

PubMed

Oberbaum, Menachem; Lysy, Joseph; Gropp, Cornelius

2011-08-01

The first clinical experiment is described in the bible: The prophet Daniel is reported being nourished during ten days by seeds and water only, in order to check if his physical state would deteriorate as a result of this minimal nutrition. In the 15th century, French surgeon Ambroise Parí experimented with a mixture of turpentine, egg protein and rose oil to treat combat wounds, which is thought to be the first clinical study to be reported. In the 19th century British scientist James Lind designed the first controlled prospective study with parallel groups, proving that ingesting citrus fruit prevents scurvy. A short time afterwards British scientist John Haygarth was the first to use a placebo drug in a clinical study. Important work on placebo was conducted by the American scientists Austin Flint and later by Henry K. Beecher, who showed that placebo itself has biological properties. The importance of comparative studies was first understood by French psychologist CLaude Bernard. He is considered the founder of the modern scientific method based on observation, analysis of data and examination of hypotheses. Bernard's work was based on the work of fellow Frenchman Pierre Charles Alexandre Louis, who is justly considered a founding father of modern epidemiology, and who was the first to use statistics in clinical experiments. Random distributions in clinical studies were reported even before this time, for instance in the work of the Flemish physician Johannes Baptista van Helmont. Danish Nobel prize winner Johannes Fibiger pioneered the use of selection bias in his work with diphtheria serum.

Efficacy and safety of acarbose chewable tablet in patients with type 2 diabetes: a multicentre, randomized, double-blinded, double-dummy positive controlled trial.

PubMed

Wu, Qian Lin; Liu, Yu Ping; Lu, Ju Ming; Wang, Chang Jiang; Yang, Tao; Dong, Ji Xiang; Li, Cheng Jiang; Ma, Jian Hua; Xue, Yao Ming; Sun, Rui Hua; Wei, Dong; Tian, Hao Ming

2012-08-01

To evaluate the effect and safety of HbA1c and glycemic control of acarbose chewable tablets in patients with type 2 diabetic. A multicentre, randomized, double-blinded, double-dummy, positive controlled clinical trial was conducted. Two hundred thirty-four Chinese patients with type 2 diabetic were enrolled in eight clinical centres, who were divided randomly into the acarbose chewable tablet group (experimental group, n = 116) and the acarbose treatment group (control group, n = 118). Two hundred seven patients (88.5%) took part in the 12-week trial. At the beginning and end of the clinical trial, HbA1c and blood glucose as well as safety indexes were measured. After the treatment, the level of finger two-hour postprandial blood glucose (PPBG) was decreased 4.15 mmol/L (26.82%) and 3.54 mmol/L (22.77%), respectively, in the experiment group and the control group. The levels of venous two-hour PPBG in the experiment group and the control group were decreased 4.04 mmol/L (25.38%) and 2.75 mmol/L (17.26%), respectively, with the means of HbA1c lowering 11.67% and 12.44%, respectively. Fasting blood glucose (FBG) also was reduced significantly in both groups. Patients in both groups showed obvious weight reduction (P < 0.0001). There were no significant differences in the incidence of adverse events between the two groups. In summary, acarbose chewable tablets have a definite curative effect in treating type 2 diabetic patients as HbA1c and blood glucose levels decreased significantly after the 12-week treatment. © 2012 Wiley Publishing Asia Pty Ltd and Chinese Cochrane Center, West China Hospital of Sichuan University.

Reconciling research and implementation in micro health insurance experiments in India: study protocol for a randomized controlled trial

PubMed Central

2011-01-01

Background Microinsurance or Community-Based Health Insurance is a promising healthcare financing mechanism, which is increasingly applied to aid rural poor persons in low-income countries. Robust empirical evidence on the causal relations between Community-Based Health Insurance and healthcare utilisation, financial protection and other areas is scarce and necessary. This paper contains a discussion of the research design of three Cluster Randomised Controlled Trials in India to measure the impact of Community-Based Health Insurance on several outcomes. Methods/Design Each trial sets up a Community-Based Health Insurance scheme among a group of micro-finance affiliate families. Villages are grouped into clusters which are congruous with pre-existing social groupings. These clusters are randomly assigned to one of three waves of implementation, ensuring the entire population is offered Community-Based Health Insurance by the end of the experiment. Each wave of treatment is preceded by a round of mixed methods evaluation, with quantitative, qualitative and spatial evidence on impact collected. Improving upon practices in published Cluster Randomised Controlled Trial literature, we detail how research design decisions have ensured that both the households offered insurance and the implementers of the Community-Based Health Insurance scheme operate in an environment replicating a non-experimental implementation. Discussion When a Cluster Randomised Controlled Trial involves randomizing within a community, generating adequate and valid conclusions requires that the research design must be made congruous with social structures within the target population, to ensure that such trials are conducted in an implementing environment which is a suitable analogue to that of a non-experimental implementing environment. PMID:21988774

Supplemental nicotine preloading for smoking cessation in posttraumatic stress disorder: Results from a randomized controlled trial

PubMed Central

Dennis, Paul A.; Kimbrel, Nathan A.; Dedert, Eric A.; Beckham, Jean C.; Dennis, Michelle F.; Calhoun, Patrick S.

2016-01-01

Background Individuals with posttraumatic stress disorder (PTSD) are more likely to smoke and more likely to relapse following a quit attempt than individuals without PTSD. Thus, there is a significant need to study promising interventions that might improve quit rates for smokers with PTSD. One such intervention, supplemental nicotine patch-preloading, entails the use of nicotine replacement therapy prior to quitting. Objective The objective of this study was to conduct a randomized controlled trial of the efficacy of supplemental nicotine patch-preloading among smokers with PTSD. We hypothesized that, relative to participants in the placebo condition, participants in the nicotine patch-preloading condition would: (1) smoke less and experience reduced craving for cigarettes during the nicotine patch-preloading phase; (2) experience less smoking-associated relief from PTSD symptoms and negative affect during the preloading phase; and (3) exhibit greater latency to lapse, and higher short- and long-term abstinence rates. Methods Sixty-three smokers with PTSD were randomized to either nicotine or placebo patch for three weeks prior to their quit date. Ecological momentary assessment was used to assess craving, smoking, PTSD symptoms, and negative affect during the preloading period. Results Nicotine patch-preloading failed to reduce smoking or craving during the preloading phase, nor was it associated with less smoking-associated relief from PTSD symptoms and negative affect. Moreover, no differences were observed between the treatment conditions for time to lapse, 6-week abstinence, or 6-month abstinence. Conclusions The findings from the present research suggest that supplemental nicotine patch-preloading is unlikely to substantially enhance quit rates among smokers with PTSD. PMID:27046670

The Impact of Prenatal Yoga on Exercise Attitudes and Behavior: Teachable moments from a Randomized Controlled Trial.

PubMed

Babbar, Shilpa; Porter, Blake W; Williams, Karen B

2017-11-01

Pregnancy serves as an opportune time for "teachable moments" to elicit positive behavior change. We evaluated change in exercise perception, behavior and gestational weight gain in participants engaged in a one-hour educational experience. Women between 28 0/7 to 36 6/7 weeks with no prior yoga experience carrying a non-anomalous singleton fetus participated in a randomized controlled trial on prenatal yoga. The yoga group engaged in a one-hour yoga class; the attention control educational group, in a one-hour presentation on exercise, nutrition and obesity in pregnancy. Maternal perception of yoga, exercise effects and current health status was conducted before and after the intervention. Gestational weight gain (GWG) and body mass index (BMI) were assessed. A postpartum survey was performed to determine self-reported behavioral changes during and after pregnancy. Over 6 months, 52 women were randomized and 46 (88%) completed the study. Women reported a more positive attitude towards exercise and yoga after the yoga intervention. Total GWG was similar (yoga 32.9 versus education 32.8 pounds, p = 0.98). Stratified by pre-pregnancy BMI, 13% gained within and 61% gained above the Institute of Medicine guidelines in each group. Of 29 inactive women prior to the intervention, 60% of the yoga group and 75% of the education group began prenatal exercises after the intervention and 50% of each group continued to exercise after delivery. There were no significant differences between groups. A one-time, one-hour intervention teaching a new exercise or educating women during pregnancy can positively impact pregnancy behaviors and perception with the potential to improve maternal and neonatal outcomes. Clinicaltrials.gov, www.clinicaltrials.gov , NCT02063711.

The Impact of Prenatal Yoga on Exercise Attitudes and Behavior: Teachable moments from a Randomized Controlled Trial.

PubMed

Babbar, Shilpa; Porter, Blake W; Williams, Karen B

2017-08-02

Pregnancy serves as an opportune time for "teachable moments" to elicit positive behavior change. We evaluated change in exercise perception, behavior and gestational weight gain in participants engaged in a one-hour educational experience. Women between 28 0/7 to 36 6/7 weeks with no prior yoga experience carrying a non-anomalous singleton fetus participated in a randomized controlled trial on prenatal yoga. The yoga group engaged in a one-hour yoga class; the attention control educational group, in a one-hour presentation on exercise, nutrition and obesity in pregnancy. Maternal perception of yoga, exercise effects and current health status was conducted before and after the intervention. Gestational weight gain (GWG) and body mass index (BMI) were assessed. A postpartum survey was performed to determine self-reported behavioral changes during and after pregnancy. Over 6 months, 52 women were randomized and 46 (88%) completed the study. Women reported a more positive attitude towards exercise and yoga after the yoga intervention. Total GWG was similar (yoga 32.9 versus education 32.8 pounds, p = 0.98). Stratified by pre-pregnancy BMI, 13% gained within and 61% gained above the Institute of Medicine guidelines in each group. Of 29 inactive women prior to the intervention, 60% of the yoga group and 75% of the education group began prenatal exercises after the intervention and 50% of each group continued to exercise after delivery. There were no significant differences between groups. A one-time, one-hour intervention teaching a new exercise or educating women during pregnancy can positively impact pregnancy behaviors and perception with the potential to improve maternal and neonatal outcomes.

Reconciling research and implementation in micro health insurance experiments in India: study protocol for a randomized controlled trial.

PubMed

Doyle, Conor; Panda, Pradeep; Van de Poel, Ellen; Radermacher, Ralf; Dror, David M

2011-10-11

Microinsurance or Community-Based Health Insurance is a promising healthcare financing mechanism, which is increasingly applied to aid rural poor persons in low-income countries. Robust empirical evidence on the causal relations between Community-Based Health Insurance and healthcare utilisation, financial protection and other areas is scarce and necessary. This paper contains a discussion of the research design of three Cluster Randomised Controlled Trials in India to measure the impact of Community-Based Health Insurance on several outcomes. Each trial sets up a Community-Based Health Insurance scheme among a group of micro-finance affiliate families. Villages are grouped into clusters which are congruous with pre-existing social groupings. These clusters are randomly assigned to one of three waves of implementation, ensuring the entire population is offered Community-Based Health Insurance by the end of the experiment. Each wave of treatment is preceded by a round of mixed methods evaluation, with quantitative, qualitative and spatial evidence on impact collected. Improving upon practices in published Cluster Randomised Controlled Trial literature, we detail how research design decisions have ensured that both the households offered insurance and the implementers of the Community-Based Health Insurance scheme operate in an environment replicating a non-experimental implementation. When a Cluster Randomised Controlled Trial involves randomizing within a community, generating adequate and valid conclusions requires that the research design must be made congruous with social structures within the target population, to ensure that such trials are conducted in an implementing environment which is a suitable analogue to that of a non-experimental implementing environment. © 2011 Doyle et al; licensee BioMed Central Ltd.

Effectiveness, usability, and cost-benefit of a virtual reality-based telerehabilitation program for balance recovery after stroke: a randomized controlled trial.

PubMed

Lloréns, Roberto; Noé, Enrique; Colomer, Carolina; Alcañiz, Mariano

2015-03-01

First, to evaluate the clinical effectiveness of a virtual reality (VR)-based telerehabilitation program in the balance recovery of individuals with hemiparesis after stroke in comparison with an in-clinic program; second, to compare the subjective experiences; and third, to contrast the costs of both programs. Single-blind, randomized, controlled trial. Neurorehabilitation unit. Chronic outpatients with stroke (N=30) with residual hemiparesis. Twenty 45-minute training sessions with the telerehabilitation system, conducted 3 times a week, in the clinic or in the home. First, Berg Balance Scale for balance assessment. The Performance-Oriented Mobility Assessment balance and gait subscales, and the Brunel Balance Assessment were secondary outcome measures. Clinical assessments were conducted at baseline, 8 weeks (posttreatment), and 12 weeks (follow-up). Second, the System Usability Scale and the Intrinsic Motivation Inventory for subjective experiences. Third, cost (in dollars). Significant improvement in both groups (in-clinic group [control] and a home-based telerehabilitation group) from the initial to the final assessment in the Berg Balance Scale (ηp(2)=.68; P=.001), in the balance (ηp(2)=.24; P=.006) and gait (ηp(2)=.57, P=.001) subscales of the Tinetti Performance-Oriented Mobility Assessment, and in the Brunel Balance Assessment (control: χ(2)=15.0; P=.002; experimental: χ(2)=21.9; P=.001). No significant differences were found between the groups in any balance scale or in the feedback questionnaires. With regard to subjective experiences, both groups considered the VR system similarly usable and motivating. The in-clinic intervention resulted in more expenses than did the telerehabilitation intervention ($654.72 per person). First, VR-based telerehabilitation interventions can promote the reacquisition of locomotor skills associated with balance in the same way as do in-clinic interventions, both complemented with a conventional therapy program; second, the usability of and motivation to use the 2 interventions can be similar; and third, telerehabilitation interventions can involve savings that vary depending on each scenario. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Effect of an Immersive Preoperative Virtual Reality Experience on Patient Reported Outcomes: A Randomized Controlled Trial.

PubMed

Bekelis, Kimon; Calnan, Daniel; Simmons, Nathan; MacKenzie, Todd A; Kakoulides, George

2017-06-01

To investigate the effect of exposure to a virtual reality (VR) environment preoperatively on patient-reported outcomes for surgical operations. There is a scarcity of well-developed quality improvement initiatives targeting patient satisfaction. We performed a randomized controlled trial of patients undergoing cranial and spinal operations in a tertiary referral center. Patients underwent a 1:1 randomization to an immersive preoperative VR experience or standard preoperative experience stratified on type of operation. The primary outcome measures were the Evaluation du Vecu de l'Anesthesie Generale (EVAN-G) score and the Amsterdam Preoperative Anxiety and Information (APAIS) score, as markers of the patient's experience during the surgical encounter. During the study period, a total of 127 patients (mean age 55.3 years, 41.9% females) underwent randomization. The average EVAN-G score was 84.3 (standard deviation, SD, 6.4) after VR, and 64.3 (SD, 11.7) after standard preoperative experience (difference, 20.0; 95% confidence interval, CI, 16.6-23.3). Exposure to an immersive VR experience also led to higher APAIS score (difference, 29.9; 95% CI, 24.5-35.2). In addition, VR led to lower preoperative VAS stress score (difference, -41.7; 95% CI, -33.1 to -50.2), and higher preoperative VAS preparedness (difference, 32.4; 95% CI, 24.9-39.8), and VAS satisfaction (difference, 33.2; 95% CI, 25.4-41.0) scores. No association was identified with VAS stress score (difference, -1.6; 95% CI, -13.4 to 10.2). In a randomized controlled trial, we demonstrated that patients exposed to preoperative VR had increased satisfaction during the surgical encounter. Harnessing the power of this technology, hospitals can create an immersive environment that minimizes stress, and enhances the perioperative experience.

Fear of childbirth in expectant fathers, subsequent childbirth experience and impact of antenatal education: subanalysis of results from a randomized controlled trial.

PubMed

Bergström, Malin; Rudman, Ann; Waldenström, Ulla; Kieler, Helle

2013-08-01

To explore if antenatal fear of childbirth in men affects their experience of the birth event and if this experience is associated with type of childbirth preparation. Data from a randomized controlled multicenter trial on antenatal education. 15 antenatal clinics in Sweden between January 2006 and May 2007. 762 men, of whom 83 (10.9%) suffered from fear of childbirth. Of these 83 men, 39 were randomized to psychoprophylaxis childbirth preparation where men were trained to coach their partners during labor and 44 to standard care antenatal preparation for childbirth and parenthood without such training. Experience of childbirth was compared between men with and without fear of childbirth regardless of randomization, and between fearful men in the randomized groups. Analyses by logistic regression adjusted for sociodemographic variables. Self-reported data on experience of childbirth including an adapted version of the Wijma Delivery Experience Questionnaire (W-DEQ B). Men with antenatal fear of childbirth more often experienced childbirth as frightening than men without fear: adjusted odds ratio 4.68, 95% confidence interval 2.67-8.20. Men with antenatal fear in the psychoprophylaxis group rated childbirth as frightening less often than those in standard care: adjusted odds ratio 0.30, 95% confidence interval 0.10-0.95. Men who suffer from antenatal fear of childbirth are at higher risk of experiencing childbirth as frightening. Childbirth preparation including training as a coach may help fearful men to a more positive childbirth experience. Additional studies are needed to support this conclusion. © 2013 Nordic Federation of Societies of Obstetrics and Gynecology.

The effects of potatoes and other carbohydrate side dishes consumed with meat on food intake, glycemia and satiety response in children

PubMed Central

Akilen, R; Deljoomanesh, N; Hunschede, S; Smith, C E; Arshad, M U; Kubant, R; Anderson, G H

2016-01-01

Background: The effect of carbohydrate (CHO) foods on blood glucose (BG) is ranked by their glycemic index (GI). Boiled and mashed potatoes (BMPs) are ranked as high GI foods, whereas pasta and rice have moderate GI rankings. The objective of this study was to compare ad libitum consumption of common CHO dishes consumed with meat on meal-time food intake and post-meal satiety, BG, insulin and gut hormones in 11- to 13-year-old normal weight children. Methods: Two randomized crossover studies were conducted. At weekly intervals, children (experiment 1: 12 males (M), 8 females (F); experiment 2: 6M, 6 F) received in random order 1 of 5 CHO side dishes of rice, pasta, BMP, fried French fries (FFF) or baked French fries (BFF) eaten freely together with a fixed amount of lean beef (100 g). In experiment-1, food intake over 30 min and subjective appetite were measured for 120 min. In experiment-2, the same outcomes were measured along with BG, plasma insulin and gut hormones. Results: The results for boys and girls were pooled as sex was not a factor. In both experiments, children consumed 30–40% less calories at meals with BMP (P<0.0001) compared with all other treatments, which were similar. BMP increased satiety, expressed as a change in appetite per kilocalorie, more than all other treatments (P<0.0001). FFF resulted in the lowest (P<0.0001) glucose and insulin at meal end and post-meal and peptide YY (PYY) post-meal. Blood measures were similar among all other treatments. Conclusions: The physiological functions of CHO foods consumed ad libitum at meal time on food intake, appetite, BG, insulin and gut hormone responses in children is not predicted by the GI. PMID:26878318

Hemoadsorption removes tumor necrosis factor, interleukin-6, and interleukin-10, reduces nuclear factor-kappaB DNA binding, and improves short-term survival in lethal endotoxemia.

PubMed

Kellum, John A; Song, Mingchen; Venkataraman, Ramesh

2004-03-01

Previous studies have shown that inflammatory mediators can be removed from the circulation with hemofiltration and that adsorption plays an important role. Because adsorptive capacity of hollow-fiber dialyzers is limited, we sought to determine whether hemoadsorption using high surface area beads would result in greater mediator removal and improved survival in experimental sepsis. Randomized controlled laboratory experiment. University laboratory. Sixty-six adult Sprague-Dawley rats. We conducted two ex vivo and two in vivo experiments. For in vivo experiments, we administered Escherichia coli endotoxin (20 mg/kg) by intravenous infusion and then randomized each animal to receive either hemoadsorption or a sham circuit for 4 hrs. Hemoadsorption was performed for 4 hrs using an arterial-venous circuit and a CytoSorb cartridge containing 10 g of polystyrene divinyl benzene copolymer beads with a biocompatible polyvinylpyrrolidone coating. Survival time was measured to a maximum of 12 hrs. In a separate set of experiments, we studied 12 animals using the same protocol except that we killed all animals at 4 hrs and removed standardized sections of liver for analysis of nuclear factor-kappaB DNA binding. Mean survival time among hemoadsorption-treated animals was 629+/-114 vs. 518+/-120 mins for sham-treated animals (p <.01). Overall survival (defined at 12 hrs) was also significantly better in the hemoadsorption group, seven of 20 vs. one of 20 (p <.05). Plasma interleukin-6 and interleukin-10 concentrations and liver nuclear factor-kappaB DNA binding were significantly reduced by hemoadsorption. Ex vivo experiments showed no endotoxin adsorption but strengthened our in vivo observations by showing rapid adsorption of tumor necrosis factor, interleukin-6, and interleukin-10. Hemoadsorption was associated with reduced inflammation and improved survival in this murine model of septic shock.

Probiotic Lactobacillus johnsonii BS15 Improves Blood Parameters Related to Immunity in Broilers Experimentally Infected with Subclinical Necrotic Enteritis

PubMed Central

Wang, Hesong; Ni, Xueqin; Qing, Xiaodan; Liu, Lei; Xin, Jinge; Luo, Min; Khalique, Abdul; Dan, Yan; Pan, Kangcheng; Jing, Bo; Zeng, Dong

2018-01-01

The probiotic strain Lactobacillus johnsonii BS15 could exert beneficial effects on growth performance, lipid metabolism, and intestinal microflora in healthy broilers and those afflicted with subclinical necrotic enteritis (SNE). In particular, BS15 prevents SNE by enhancing intestinal immunity. To further understand the immune regulatory mechanism of BS15, we evaluated its effects on the overall immunity of broilers by determining blood parameters in healthy and SNE broilers. In this study, two experiments were conducted. Experiment 1 involved a 42-day experimental period and used 450 1-day-old male chicks. The chicks were randomly divided into three groups and fed with a basal diet with or without 1 × 105 or 106 colony-forming units (cfu) BS15/g as feed. Experiment 2 involved a 28-day experimental period and used 180 1-day-old male chicks. The chicks were randomly allotted into three groups and given with or without 1 × 106 cfu BS15/g BS15 as feed. SNE infection was treated in all broilers, except in those in the normal diet group. Antioxidant abilities, immunoglobulins, and cytokines in the serum were assessed. T-lymphocyte subsets in peripheral blood were also determined. The first experiment demonstrated that BS15 enhanced the antioxidant abilities; the serum levels of immunoglobulins, interleukin-2, and interferon-gamma; and CD3+CD4+ T-lymphocyte percentage in peripheral blood on day 21. However, limited significant changes were observed on day 42. The second experiment revealed that BS15 supplementation positively influenced the antioxidant abilities and increased the serum levels of immunoglobulins and cytokines that were affected by SNE. BS15 also positively affected T-lymphocyte subsets in peripheral blood during SNE infection. These findings suggest that BS15 supplementation may prevent SNE in broilers by improving blood parameters related to immunity and enhancing intestinal immunity. Furthermore, BS15 supplementation can improve blood parameters in healthy broilers, especially at the starter phase. PMID:29441047

The effects of potatoes and other carbohydrate side dishes consumed with meat on food intake, glycemia and satiety response in children.

PubMed

Akilen, R; Deljoomanesh, N; Hunschede, S; Smith, C E; Arshad, M U; Kubant, R; Anderson, G H

2016-02-15

The effect of carbohydrate (CHO) foods on blood glucose (BG) is ranked by their glycemic index (GI). Boiled and mashed potatoes (BMPs) are ranked as high GI foods, whereas pasta and rice have moderate GI rankings. The objective of this study was to compare ad libitum consumption of common CHO dishes consumed with meat on meal-time food intake and post-meal satiety, BG, insulin and gut hormones in 11- to 13-year-old normal weight children. Two randomized crossover studies were conducted. At weekly intervals, children (experiment 1: 12 males (M), 8 females (F); experiment 2: 6M, 6 F) received in random order 1 of 5 CHO side dishes of rice, pasta, BMP, fried French fries (FFF) or baked French fries (BFF) eaten freely together with a fixed amount of lean beef (100 g). In experiment-1, food intake over 30 min and subjective appetite were measured for 120 min. In experiment-2, the same outcomes were measured along with BG, plasma insulin and gut hormones. The results for boys and girls were pooled as sex was not a factor. In both experiments, children consumed 30-40% less calories at meals with BMP (P<0.0001) compared with all other treatments, which were similar. BMP increased satiety, expressed as a change in appetite per kilocalorie, more than all other treatments (P<0.0001). FFF resulted in the lowest (P<0.0001) glucose and insulin at meal end and post-meal and peptide YY (PYY) post-meal. Blood measures were similar among all other treatments. The physiological functions of CHO foods consumed ad libitum at meal time on food intake, appetite, BG, insulin and gut hormone responses in children is not predicted by the GI.

Probiotic Lactobacillus johnsonii BS15 Improves Blood Parameters Related to Immunity in Broilers Experimentally Infected with Subclinical Necrotic Enteritis.

PubMed

Wang, Hesong; Ni, Xueqin; Qing, Xiaodan; Liu, Lei; Xin, Jinge; Luo, Min; Khalique, Abdul; Dan, Yan; Pan, Kangcheng; Jing, Bo; Zeng, Dong

2018-01-01

The probiotic strain Lactobacillus johnsonii BS15 could exert beneficial effects on growth performance, lipid metabolism, and intestinal microflora in healthy broilers and those afflicted with subclinical necrotic enteritis (SNE). In particular, BS15 prevents SNE by enhancing intestinal immunity. To further understand the immune regulatory mechanism of BS15, we evaluated its effects on the overall immunity of broilers by determining blood parameters in healthy and SNE broilers. In this study, two experiments were conducted. Experiment 1 involved a 42-day experimental period and used 450 1-day-old male chicks. The chicks were randomly divided into three groups and fed with a basal diet with or without 1 × 10 5 or 10 6 colony-forming units (cfu) BS15/g as feed. Experiment 2 involved a 28-day experimental period and used 180 1-day-old male chicks. The chicks were randomly allotted into three groups and given with or without 1 × 10 6 cfu BS15/g BS15 as feed. SNE infection was treated in all broilers, except in those in the normal diet group. Antioxidant abilities, immunoglobulins, and cytokines in the serum were assessed. T-lymphocyte subsets in peripheral blood were also determined. The first experiment demonstrated that BS15 enhanced the antioxidant abilities; the serum levels of immunoglobulins, interleukin-2, and interferon-gamma; and CD3 + CD4 + T-lymphocyte percentage in peripheral blood on day 21. However, limited significant changes were observed on day 42. The second experiment revealed that BS15 supplementation positively influenced the antioxidant abilities and increased the serum levels of immunoglobulins and cytokines that were affected by SNE. BS15 also positively affected T-lymphocyte subsets in peripheral blood during SNE infection. These findings suggest that BS15 supplementation may prevent SNE in broilers by improving blood parameters related to immunity and enhancing intestinal immunity. Furthermore, BS15 supplementation can improve blood parameters in healthy broilers, especially at the starter phase.