Sample records for quasi-experimental design involving
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Graphical Models for Quasi-Experimental Designs
ERIC Educational Resources Information Center
Kim, Yongnam; Steiner, Peter M.; Hall, Courtney E.; Su, Dan
2016-01-01
Experimental and quasi-experimental designs play a central role in estimating cause-effect relationships in education, psychology, and many other fields of the social and behavioral sciences. This paper presents and discusses the causal graphs of experimental and quasi-experimental designs. For quasi-experimental designs the authors demonstrate…
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Quasi-Experimental Designs for Causal Inference
ERIC Educational Resources Information Center
Kim, Yongnam; Steiner, Peter
2016-01-01
When randomized experiments are infeasible, quasi-experimental designs can be exploited to evaluate causal treatment effects. The strongest quasi-experimental designs for causal inference are regression discontinuity designs, instrumental variable designs, matching and propensity score designs, and comparative interrupted time series designs. This…
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Quasi experimental designs in pharmacist intervention research.
Krass, Ines
2016-06-01
Background In the field of pharmacist intervention research it is often difficult to conform to the rigorous requirements of the "true experimental" models, especially the requirement of randomization. When randomization is not feasible, a practice based researcher can choose from a range of "quasi-experimental designs" i.e., non-randomised and at time non controlled. Objective The aim of this article was to provide an overview of quasi-experimental designs, discuss their strengths and weaknesses and to investigate their application in pharmacist intervention research over the previous decade. Results In the literature quasi experimental studies may be classified into five broad categories: quasi-experimental design without control groups; quasi-experimental design that use control groups with no pre-test; quasi-experimental design that use control groups and pre-tests; interrupted time series and stepped wedge designs. Quasi-experimental study design has consistently featured in the evolution of pharmacist intervention research. The most commonly applied of all quasi experimental designs in the practice based research literature are the one group pre-post-test design and the non-equivalent control group design i.e., (untreated control group with dependent pre-tests and post-tests) and have been used to test the impact of pharmacist interventions in general medications management as well as in specific disease states. Conclusion Quasi experimental studies have a role to play as proof of concept, in the pilot phases of interventions when testing different intervention components, especially in complex interventions. They serve to develop an understanding of possible intervention effects: while in isolation they yield weak evidence of clinical efficacy, taken collectively, they help build a body of evidence in support of the value of pharmacist interventions across different practice settings and countries. However, when a traditional RCT is not feasible for
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Quasi-experimental study designs series-paper 9: collecting data from quasi-experimental studies.
Aloe, Ariel M; Becker, Betsy Jane; Duvendack, Maren; Valentine, Jeffrey C; Shemilt, Ian; Waddington, Hugh
2017-09-01
To identify variables that must be coded when synthesizing primary studies that use quasi-experimental designs. All quasi-experimental (QE) designs. When designing a systematic review of QE studies, potential sources of heterogeneity-both theory-based and methodological-must be identified. We outline key components of inclusion criteria for syntheses of quasi-experimental studies. We provide recommendations for coding content-relevant and methodological variables and outlined the distinction between bivariate effect sizes and partial (i.e., adjusted) effect sizes. Designs used and controls used are viewed as of greatest importance. Potential sources of bias and confounding are also addressed. Careful consideration must be given to inclusion criteria and the coding of theoretical and methodological variables during the design phase of a synthesis of quasi-experimental studies. The success of the meta-regression analysis relies on the data available to the meta-analyst. Omission of critical moderator variables (i.e., effect modifiers) will undermine the conclusions of a meta-analysis. Copyright © 2017 Elsevier Inc. All rights reserved.
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True and Quasi-Experimental Designs. ERIC/AE Digest.
ERIC Educational Resources Information Center
Gribbons, Barry; Herman, Joan
Among the different types of experimental design are two general categories: true experimental designs and quasi- experimental designs. True experimental designs include more than one purposively created group, common measured outcomes, and random assignment. Quasi-experimental designs are commonly used when random assignment is not practical or…
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Schweizer, Marin L; Braun, Barbara I; Milstone, Aaron M
2016-10-01
Quasi-experimental studies evaluate the association between an intervention and an outcome using experiments in which the intervention is not randomly assigned. Quasi-experimental studies are often used to evaluate rapid responses to outbreaks or other patient safety problems requiring prompt, nonrandomized interventions. Quasi-experimental studies can be categorized into 3 major types: interrupted time-series designs, designs with control groups, and designs without control groups. This methods paper highlights key considerations for quasi-experimental studies in healthcare epidemiology and antimicrobial stewardship, including study design and analytic approaches to avoid selection bias and other common pitfalls of quasi-experimental studies. Infect Control Hosp Epidemiol 2016;1-6.
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Graphical Models for Quasi-Experimental Designs
ERIC Educational Resources Information Center
Steiner, Peter M.; Kim, Yongnam; Hall, Courtney E.; Su, Dan
2017-01-01
Randomized controlled trials (RCTs) and quasi-experimental designs like regression discontinuity (RD) designs, instrumental variable (IV) designs, and matching and propensity score (PS) designs are frequently used for inferring causal effects. It is well known that the features of these designs facilitate the identification of a causal estimand…
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Schweizer, Marin L.; Braun, Barbara I.; Milstone, Aaron M.
2016-01-01
Quasi-experimental studies evaluate the association between an intervention and an outcome using experiments in which the intervention is not randomly assigned. Quasi-experimental studies are often used to evaluate rapid responses to outbreaks or other patient safety problems requiring prompt non-randomized interventions. Quasi-experimental studies can be categorized into three major types: interrupted time series designs, designs with control groups, and designs without control groups. This methods paper highlights key considerations for quasi-experimental studies in healthcare epidemiology and antimicrobial stewardship including study design and analytic approaches to avoid selection bias and other common pitfalls of quasi-experimental studies. PMID:27267457
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Using Propensity Scores in Quasi-Experimental Designs to Equate Groups
ERIC Educational Resources Information Center
Lane, Forrest C.; Henson, Robin K.
2010-01-01
Education research rarely lends itself to large scale experimental research and true randomization, leaving the researcher to quasi-experimental designs. The problem with quasi-experimental research is that underlying factors may impact group selection and lead to potentially biased results. One way to minimize the impact of non-randomization is…
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Quasi-experimental study designs series-paper 7: assessing the assumptions.
Bärnighausen, Till; Oldenburg, Catherine; Tugwell, Peter; Bommer, Christian; Ebert, Cara; Barreto, Mauricio; Djimeu, Eric; Haber, Noah; Waddington, Hugh; Rockers, Peter; Sianesi, Barbara; Bor, Jacob; Fink, Günther; Valentine, Jeffrey; Tanner, Jeffrey; Stanley, Tom; Sierra, Eduardo; Tchetgen, Eric Tchetgen; Atun, Rifat; Vollmer, Sebastian
2017-09-01
Quasi-experimental designs are gaining popularity in epidemiology and health systems research-in particular for the evaluation of health care practice, programs, and policy-because they allow strong causal inferences without randomized controlled experiments. We describe the concepts underlying five important quasi-experimental designs: Instrumental Variables, Regression Discontinuity, Interrupted Time Series, Fixed Effects, and Difference-in-Differences designs. We illustrate each of the designs with an example from health research. We then describe the assumptions required for each of the designs to ensure valid causal inference and discuss the tests available to examine the assumptions. Copyright © 2017 Elsevier Inc. All rights reserved.
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Study design elements for rigorous quasi-experimental comparative effectiveness research.
Maciejewski, Matthew L; Curtis, Lesley H; Dowd, Bryan
2013-03-01
Quasi-experiments are likely to be the workhorse study design used to generate evidence about the comparative effectiveness of alternative treatments, because of their feasibility, timeliness, affordability and external validity compared with randomized trials. In this review, we outline potential sources of discordance in results between quasi-experiments and experiments, review study design choices that can improve the internal validity of quasi-experiments, and outline innovative data linkage strategies that may be particularly useful in quasi-experimental comparative effectiveness research. There is an urgent need to resolve the debate about the evidentiary value of quasi-experiments since equal consideration of rigorous quasi-experiments will broaden the base of evidence that can be brought to bear in clinical decision-making and governmental policy-making.
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A More Rigorous Quasi-Experimental Alternative to the One-Group Pretest-Posttest Design.
ERIC Educational Resources Information Center
Johnson, Craig W.
1986-01-01
A simple quasi-experimental design is described which may have utility in a variety of applied and laboratory research settings where ordinarily the one-group pretest-posttest pre-experimental design might otherwise be the procedure of choice. The design approaches the internal validity of true experimental designs while optimizing external…
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Quasi-experimental study designs series-paper 1: introduction: two historical lineages.
Bärnighausen, Till; Røttingen, John-Arne; Rockers, Peter; Shemilt, Ian; Tugwell, Peter
2017-09-01
The objective of this study was to contrast the historical development of experiments and quasi-experiments and provide the motivation for a journal series on quasi-experimental designs in health research. A short historical narrative, with concrete examples, and arguments based on an understanding of the practice of health research and evidence synthesis. Health research has played a key role in developing today's gold standard for causal inference-the randomized controlled multiply blinded trial. Historically, allocation approaches developed from convenience and purposive allocation to alternate and, finally, to random allocation. This development was motivated both by concerns for manipulation in allocation as well as statistical and theoretical developments demonstrating the power of randomization in creating counterfactuals for causal inference. In contrast to the sequential development of experiments, quasi-experiments originated at very different points in time, from very different scientific perspectives, and with frequent and long interruptions in their methodological development. Health researchers have only recently started to recognize the value of quasi-experiments for generating novel insights on causal relationships. While quasi-experiments are unlikely to replace experiments in generating the efficacy and safety evidence required for clinical guidelines and regulatory approval of medical technologies, quasi-experiments can play an important role in establishing the effectiveness of health care practice, programs, and policies. The papers in this series describe and discuss a range of important issues in utilizing quasi-experimental designs for primary research and quasi-experimental results for evidence synthesis. Copyright © 2017 Elsevier Inc. All rights reserved.
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Segmented Polynomial Models in Quasi-Experimental Research.
ERIC Educational Resources Information Center
Wasik, John L.
1981-01-01
The use of segmented polynomial models is explained. Examples of design matrices of dummy variables are given for the least squares analyses of time series and discontinuity quasi-experimental research designs. Linear combinations of dummy variable vectors appear to provide tests of effects in the two quasi-experimental designs. (Author/BW)
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Quasi-experimental study designs series-paper 6: risk of bias assessment.
Waddington, Hugh; Aloe, Ariel M; Becker, Betsy Jane; Djimeu, Eric W; Hombrados, Jorge Garcia; Tugwell, Peter; Wells, George; Reeves, Barney
2017-09-01
Rigorous and transparent bias assessment is a core component of high-quality systematic reviews. We assess modifications to existing risk of bias approaches to incorporate rigorous quasi-experimental approaches with selection on unobservables. These are nonrandomized studies using design-based approaches to control for unobservable sources of confounding such as difference studies, instrumental variables, interrupted time series, natural experiments, and regression-discontinuity designs. We review existing risk of bias tools. Drawing on these tools, we present domains of bias and suggest directions for evaluation questions. The review suggests that existing risk of bias tools provide, to different degrees, incomplete transparent criteria to assess the validity of these designs. The paper then presents an approach to evaluating the internal validity of quasi-experiments with selection on unobservables. We conclude that tools for nonrandomized studies of interventions need to be further developed to incorporate evaluation questions for quasi-experiments with selection on unobservables. Copyright © 2017 Elsevier Inc. All rights reserved.
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Lavis, John N; Bärnighausen, Till; El-Jardali, Fadi
2017-09-01
To describe the infrastructure available to support the production of policy-relevant health systems research syntheses, particularly those incorporating quasi-experimental evidence, and the tools available to support the use of these syntheses. Literature review. The general challenges associated with the available infrastructure include their sporadic nature or limited coverage of issues and countries, whereas the specific ones related to policy-relevant syntheses of quasi-experimental evidence include the lack of mechanism to register synthesis titles and scoping review protocols, the limited number of groups preparing user-friendly summaries, and the difficulty of finding quasi-experimental studies for inclusion in rapid syntheses and research syntheses more generally. Although some new tools have emerged in recent years, such as guidance workbooks and citizen briefs and panels, challenges related to using available tools to support the use of policy-relevant syntheses of quasi-experimental evidence arise from such studies potentially being harder for policymakers and stakeholders to commission and understand. Policymakers, stakeholders, and researchers need to expand the coverage and institutionalize the use of the available infrastructure and tools to support the use of health system research syntheses containing quasi-experimental evidence. Copyright © 2017 Elsevier Inc. All rights reserved.
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Rockers, Peter C; Tugwell, Peter; Røttingen, John-Arne; Bärnighausen, Till
2017-09-01
Although the number of quasi-experiments conducted by health researchers has increased in recent years, there clearly remains unrealized potential for using these methods for causal evaluation of health policies and programs globally. This article proposes five prescriptions for capturing the full value of quasi-experiments for health research. First, new funding opportunities targeting proposals that use quasi-experimental methods should be made available to a broad pool of health researchers. Second, administrative data from health programs, often amenable to quasi-experimental analysis, should be made more accessible to researchers. Third, training in quasi-experimental methods should be integrated into existing health science graduate programs to increase global capacity to use these methods. Fourth, clear guidelines for primary research and synthesis of evidence from quasi-experiments should be developed. Fifth, strategic investments should be made to continue to develop new innovations in quasi-experimental methodologies. Tremendous opportunities exist to expand the use of quasi-experimental methods to increase our understanding of which health programs and policies work and which do not. Health researchers should continue to expand their commitment to rigorous causal evaluation with quasi-experimental methods, and international institutions should increase their support for these efforts. Copyright © 2017 Elsevier Inc. All rights reserved.
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Lahey, Benjamin B.; Turkheimer, Eric; Lichtenstein, Paul
2013-01-01
Researchers have identified environmental risks that predict subsequent psychological and medical problems. Based on these correlational findings, researchers have developed and tested complex developmental models and have examined biological moderating factors (e.g., gene–environment interactions). In this context, we stress the critical need for researchers to use family-based, quasi-experimental designs when trying to integrate genetic and social science research involving environmental variables because these designs rigorously examine causal inferences by testing competing hypotheses. We argue that sibling comparison, offspring of twins or siblings, in vitro fertilization designs, and other genetically informed approaches play a unique role in bridging gaps between basic biological and social science research. We use studies on maternal smoking during pregnancy to exemplify these principles. PMID:23927516
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D'Onofrio, Brian M; Lahey, Benjamin B; Turkheimer, Eric; Lichtenstein, Paul
2013-10-01
Researchers have identified environmental risks that predict subsequent psychological and medical problems. Based on these correlational findings, researchers have developed and tested complex developmental models and have examined biological moderating factors (e.g., gene-environment interactions). In this context, we stress the critical need for researchers to use family-based, quasi-experimental designs when trying to integrate genetic and social science research involving environmental variables because these designs rigorously examine causal inferences by testing competing hypotheses. We argue that sibling comparison, offspring of twins or siblings, in vitro fertilization designs, and other genetically informed approaches play a unique role in bridging gaps between basic biological and social science research. We use studies on maternal smoking during pregnancy to exemplify these principles.
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The Use and Interpretation of Quasi-Experimental Studies in Medical Informatics
Harris, Anthony D.; McGregor, Jessina C.; Perencevich, Eli N.; Furuno, Jon P.; Zhu, Jingkun; Peterson, Dan E.; Finkelstein, Joseph
2006-01-01
Quasi-experimental study designs, often described as nonrandomized, pre-post intervention studies, are common in the medical informatics literature. Yet little has been written about the benefits and limitations of the quasi-experimental approach as applied to informatics studies. This paper outlines a relative hierarchy and nomenclature of quasi-experimental study designs that is applicable to medical informatics intervention studies. In addition, the authors performed a systematic review of two medical informatics journals, the Journal of the American Medical Informatics Association (JAMIA) and the International Journal of Medical Informatics (IJMI), to determine the number of quasi-experimental studies published and how the studies are classified on the above-mentioned relative hierarchy. They hope that future medical informatics studies will implement higher level quasi-experimental study designs that yield more convincing evidence for causal links between medical informatics interventions and outcomes. PMID:16221933
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Experimental and Quasi-Experimental Design.
ERIC Educational Resources Information Center
Cottrell, Edward B.
With an emphasis on the problems of control of extraneous variables and threats to internal and external validity, the arrangement or design of experiments is discussed. The purpose of experimentation in an educational institution, and the principles governing true experimentation (randomization, replication, and control) are presented, as are…
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Wang, Jiale; Alves, Tiago V; Trindade, Fabiane J; de Aquino, Caroline B; Pieretti, Joana C; Domingues, Sergio H; Ando, Romulo A; Ornellas, Fernando R; Camargo, Pedro H C
2015-11-23
By a combination of theoretical and experimental design, we probed the effect of a quasi-single electron on the surface plasmon resonance (SPR)-mediated catalytic activities of Ag nanoparticles. Specifically, we started by theoretically investigating how the E-field distribution around the surface of a Ag nanosphere was influenced by static electric field induced by one, two, or three extra fixed electrons embedded in graphene oxide (GO) next to the Ag nanosphere. We found that the presence of the extra electron(s) changed the E-field distributions and led to higher electric field intensities. Then, we experimentally observed that a quasi-single electron trapped at the interface between GO and Ag NPs in Ag NPs supported on graphene oxide (GO-Ag NPs) led to higher catalytic activities as compared to Ag and GO-Ag NPs without electrons trapped at the interface, representing the first observation of catalytic enhancement promoted by a quasi-single electron. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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Rockers, Peter C; Tugwell, Peter; Grimshaw, Jeremy; Oliver, Sandy; Atun, Rifat; Røttingen, John-Arne; Fretheim, Atle; Ranson, M Kent; Daniels, Karen; Luiza, Vera Lucia; Bärnighausen, Till
2017-09-01
Evidence from quasi-experimental studies is often excluded from systematic reviews of health systems research despite the fact that such studies can provide strong causal evidence when well conducted. This article discusses global coordination of efforts to institutionalize the inclusion of causal evidence from quasi-experiments in systematic reviews of health systems research. In particular, we are concerned with identifying opportunities for strengthening capacity at the global and local level for implementing protocols necessary to ensure that reviews that include quasi-experiments are consistently of the highest quality. We first describe the current state of the global infrastructure that facilitates the production of systematic reviews of health systems research. We identify five important types of actors operating within this infrastructure: review authors; synthesis collaborations that facilitate the review process; synthesis interest groups that supplement the work of the larger collaborations; review funders; and end users, including policymakers. Then, we examine opportunities for intervening to build the capacity of each type of actors to support the inclusion of quasi-experiments in reviews. Finally, we suggest practical next steps for proceeding with capacity building efforts. Because of the complexity and relative nascence of the field, we recommend a carefully planned and executed approach to strengthening global capacity for the inclusion of quasi-experimental studies in systematic reviews. Copyright © 2017 Elsevier Inc. All rights reserved.
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Selecting and Improving Quasi-Experimental Designs in Effectiveness and Implementation Research.
Handley, Margaret A; Lyles, Courtney R; McCulloch, Charles; Cattamanchi, Adithya
2018-04-01
Interventional researchers face many design challenges when assessing intervention implementation in real-world settings. Intervention implementation requires holding fast on internal validity needs while incorporating external validity considerations (such as uptake by diverse subpopulations, acceptability, cost, and sustainability). Quasi-experimental designs (QEDs) are increasingly employed to achieve a balance between internal and external validity. Although these designs are often referred to and summarized in terms of logistical benefits, there is still uncertainty about (a) selecting from among various QEDs and (b) developing strategies to strengthen the internal and external validity of QEDs. We focus here on commonly used QEDs (prepost designs with nonequivalent control groups, interrupted time series, and stepped-wedge designs) and discuss several variants that maximize internal and external validity at the design, execution and implementation, and analysis stages.
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Multiple Measures of Juvenile Drug Court Effectiveness: Results of a Quasi-Experimental Design
ERIC Educational Resources Information Center
Rodriguez, Nancy; Webb, Vincent J.
2004-01-01
Prior studies of juvenile drug courts have been constrained by small samples, inadequate comparison groups, or limited outcome measures. The authors report on a 3-year evaluation that examines the impact of juvenile drug court participation on recidivism and drug use. A quasi-experimental design is used to compare juveniles assigned to drug court…
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Inclusion of quasi-experimental studies in systematic reviews of health systems research.
Rockers, Peter C; Røttingen, John-Arne; Shemilt, Ian; Tugwell, Peter; Bärnighausen, Till
2015-04-01
Systematic reviews of health systems research commonly limit studies for evidence synthesis to randomized controlled trials. However, well-conducted quasi-experimental studies can provide strong evidence for causal inference. With this article, we aim to stimulate and inform discussions on including quasi-experiments in systematic reviews of health systems research. We define quasi-experimental studies as those that estimate causal effect sizes using exogenous variation in the exposure of interest that is not directly controlled by the researcher. We incorporate this definition into a non-hierarchical three-class taxonomy of study designs - experiments, quasi-experiments, and non-experiments. Based on a review of practice in three disciplines related to health systems research (epidemiology, economics, and political science), we discuss five commonly used study designs that fit our definition of quasi-experiments: natural experiments, instrumental variable analyses, regression discontinuity analyses, interrupted times series studies, and difference studies including controlled before-and-after designs, difference-in-difference designs and fixed effects analyses of panel data. We further review current practices regarding quasi-experimental studies in three non-health fields that utilize systematic reviews (education, development, and environment studies) to inform the design of approaches for synthesizing quasi-experimental evidence in health systems research. Ultimately, the aim of any review is practical: to provide useful information for policymakers, practitioners, and researchers. Future work should focus on building a consensus among users and producers of systematic reviews regarding the inclusion of quasi-experiments. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
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Quasi-experimental study designs series-paper 4: uses and value.
Bärnighausen, Till; Tugwell, Peter; Røttingen, John-Arne; Shemilt, Ian; Rockers, Peter; Geldsetzer, Pascal; Lavis, John; Grimshaw, Jeremy; Daniels, Karen; Brown, Annette; Bor, Jacob; Tanner, Jeffery; Rashidian, Arash; Barreto, Mauricio; Vollmer, Sebastian; Atun, Rifat
2017-09-01
Quasi-experimental studies are increasingly used to establish causal relationships in epidemiology and health systems research. Quasi-experimental studies offer important opportunities to increase and improve evidence on causal effects: (1) they can generate causal evidence when randomized controlled trials are impossible; (2) they typically generate causal evidence with a high degree of external validity; (3) they avoid the threats to internal validity that arise when participants in nonblinded experiments change their behavior in response to the experimental assignment to either intervention or control arm (such as compensatory rivalry or resentful demoralization); (4) they are often well suited to generate causal evidence on long-term health outcomes of an intervention, as well as nonhealth outcomes such as economic and social consequences; and (5) they can often generate evidence faster and at lower cost than experiments and other intervention studies. Copyright © 2017 Elsevier Inc. All rights reserved.
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Handley, Margaret A; Schillinger, Dean; Shiboski, Stephen
2011-01-01
Although randomized controlled trials are often a gold standard for determining intervention effects, in the area of practice-based research (PBR), there are many situations in which individual randomization is not possible. Alternative approaches to evaluating interventions have received increased attention, particularly those that can retain elements of randomization such that they can be considered "controlled" trials. Methodological design elements and practical implementation considerations for two quasi-experimental design approaches that have considerable promise in PBR settings--the stepped-wedge design, and a variant of this design, a wait-list cross-over design, are presented along with a case study from a recent PBR intervention for patients with diabetes. PBR-relevant design features include: creation of a cohort over time that collects control data but allows all participants (clusters or patients) to receive the intervention; staggered introduction of clusters; multiple data collection points; and one-way cross-over into the intervention arm. Practical considerations include: randomization versus stratification, training run in phases; and extended time period for overall study completion. Several design features of practice based research studies can be adapted to local circumstances yet retain elements to improve methodological rigor. Studies that utilize these methods, such as the stepped-wedge design and the wait-list cross-over design, can increase the evidence base for controlled studies conducted within the complex environment of PBR.
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A Customized Intervention for Dementia Caregivers: A Quasi-Experimental Design.
Wawrziczny, Emilie; Larochette, Clotilde; Papo, David; Constant, Emilie; Ducharme, Francine; Kergoat, Marie-Jeanne; Pasquier, Florence; Antoine, Pascal
2018-04-01
The aim of this study is to test the effects of a customized intervention on distress among caregivers of persons with dementia (PWD) using a quasi-experimental design. Fifty-one spouse caregivers in the experimental group and 51 in the control group participated in the study. The effects of the intervention were examined by comparing caregivers' responses with questionnaires at pre-intervention baseline (T0) and immediately after intervention (T1). Differences were quantified using repeated-measures ANOVA. The analyses indicated a stabilizing effect of the intervention on caregivers' perceptions of PWD's daily functioning, self-esteem related to caregiving, quality of family support, and feeling of distress. Linear increases were observed regarding sense of preparedness and impact on daily routine, while no differences (interaction and linear effects) were observed for degree of self-efficacy, depression, impact on finances, or self-rated health. These findings show a preliminary efficacy of the intervention proposed in this study to prevent the exacerbation of caregivers' distress.
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Markert, Ronald J; O'Neill, Sally C; Bhatia, Subhash C
2003-01-01
The objectives of continuing medical education (CME) programs include knowledge acquisition, skill development, clinical reasoning and decision making, and health care outcomes. We conducted a year-long medical education research study in which knowledge acquisition in our CME programs was assessed. A randomized separate-sample pretest/past-test design, a quasi-experimental technique, was used. Nine CME programs with a sufficient number of participants were identified a priori. Knowledge acquisition was compared between the control group and the intervention group for the nine individual programs and for the combined programs. A total of 667 physicians, nurses, and other health professionals participated. Significant gain in knowledge was found for six programs: Perinatology, Pain Management, Fertility Care 2, Pediatrics, Colorectal Diseases, and Alzheimer's Disease (each p < .001). Also, the intervention group differed from the control group when the nine programs were combined (p < .001), with an effect size of .84. The use of sound quasi-experimental research methodology (separate-sample pretest/post-test design), the inclusion of a representative sample of CME programs, and the analysis of nearly 700 subjects led us to have confidence in concluding that our CME participants acquired a meaningful amount of new knowledge.
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Glanville, Julie; Eyers, John; Jones, Andrew M; Shemilt, Ian; Wang, Grace; Johansen, Marit; Fiander, Michelle; Rothstein, Hannah
2017-09-01
This article reviews the available evidence and guidance on methods to identify reports of quasi-experimental (QE) studies to inform systematic reviews of health care, public health, international development, education, crime and justice, and social welfare. Research, guidance, and examples of search strategies were identified by searching a range of databases, key guidance documents, selected reviews, conference proceedings, and personal communication. Current practice and research evidence were summarized. Four thousand nine hundred twenty-four records were retrieved by database searches, and additional documents were obtained by other searches. QE studies are challenging to identify efficiently because they have no standardized nomenclature and may be indexed in various ways. Reliable search filters are not available. There is a lack of specific resources devoted to collecting QE studies and little evidence on where best to search. Searches to identify QE studies should search a range of resources and, until indexing improves, use strategies that focus on the topic rather than the study design. Better definitions, better indexing in databases, prospective registers, and reporting guidance are required to improve the retrieval of QE studies and promote systematic reviews of what works based on the evidence from such studies. Copyright © 2017 Elsevier Inc. All rights reserved.
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NASA Astrophysics Data System (ADS)
Saini, K. K.; Sehgal, R. K.; Sethi, B. L.
2008-10-01
In this paper major reliability estimators are analyzed and there comparatively result are discussed. There strengths and weaknesses are evaluated in this case study. Each of the reliability estimators has certain advantages and disadvantages. Inter-rater reliability is one of the best ways to estimate reliability when your measure is an observation. However, it requires multiple raters or observers. As an alternative, you could look at the correlation of ratings of the same single observer repeated on two different occasions. Each of the reliability estimators will give a different value for reliability. In general, the test-retest and inter-rater reliability estimates will be lower in value than the parallel forms and internal consistency ones because they involve measuring at different times or with different raters. Since reliability estimates are often used in statistical analyses of quasi-experimental designs.
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Alsaggaf, Rotana; O'Hara, Lyndsay M; Stafford, Kristen A; Leekha, Surbhi; Harris, Anthony D
2018-02-01
OBJECTIVE A systematic review of quasi-experimental studies in the field of infectious diseases was published in 2005. The aim of this study was to assess improvements in the design and reporting of quasi-experiments 10 years after the initial review. We also aimed to report the statistical methods used to analyze quasi-experimental data. DESIGN Systematic review of articles published from January 1, 2013, to December 31, 2014, in 4 major infectious disease journals. METHODS Quasi-experimental studies focused on infection control and antibiotic resistance were identified and classified based on 4 criteria: (1) type of quasi-experimental design used, (2) justification of the use of the design, (3) use of correct nomenclature to describe the design, and (4) statistical methods used. RESULTS Of 2,600 articles, 173 (7%) featured a quasi-experimental design, compared to 73 of 2,320 articles (3%) in the previous review (P<.01). Moreover, 21 articles (12%) utilized a study design with a control group; 6 (3.5%) justified the use of a quasi-experimental design; and 68 (39%) identified their design using the correct nomenclature. In addition, 2-group statistical tests were used in 75 studies (43%); 58 studies (34%) used standard regression analysis; 18 (10%) used segmented regression analysis; 7 (4%) used standard time-series analysis; 5 (3%) used segmented time-series analysis; and 10 (6%) did not utilize statistical methods for comparisons. CONCLUSIONS While some progress occurred over the decade, it is crucial to continue improving the design and reporting of quasi-experimental studies in the fields of infection control and antibiotic resistance to better evaluate the effectiveness of important interventions. Infect Control Hosp Epidemiol 2018;39:170-176.
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ERIC Educational Resources Information Center
Petridou, Alexandra; Nicolaidou, Maria; Karagiorgi, Yiasemina
2017-01-01
Self-efficacy is extensively discussed within social cognitive theory. This study aimed to explore the impact of professional development and practice on school leaders' self-efficacy in Cyprus. A quasi-experimental design involving 2 groups of novice secondary deputy head teachers was employed. All participants practised leadership at the time,…
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Threats to the Internal Validity of Experimental and Quasi-Experimental Research in Healthcare.
Flannelly, Kevin J; Flannelly, Laura T; Jankowski, Katherine R B
2018-01-01
The article defines, describes, and discusses the seven threats to the internal validity of experiments discussed by Donald T. Campbell in his classic 1957 article: history, maturation, testing, instrument decay, statistical regression, selection, and mortality. These concepts are said to be threats to the internal validity of experiments because they pose alternate explanations for the apparent causal relationship between the independent variable and dependent variable of an experiment if they are not adequately controlled. A series of simple diagrams illustrate three pre-experimental designs and three true experimental designs discussed by Campbell in 1957 and several quasi-experimental designs described in his book written with Julian C. Stanley in 1966. The current article explains why each design controls for or fails to control for these seven threats to internal validity.
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Preliminary Experimental Investigation of Quasi Achromat scheme at Advanced Photon Source
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sun, Yipeng; Shang, Hairong
Next generation storage rings require weaker dipolemagnets and stronger quadrupole focusing to achieve very low emittance. To suppress the geometric and chromatic optics aberrations introduced by the strong sextupoles, achromat and quasi achromat schemes are applied in the lattice design to improve the beam dynamics performance. In this paper, some preliminary experimental investigation of the quasi achromat scheme at the Advanced Photon Source (APS) are presented. Three different operation lattices are compared on their beam dynamics performance. Although none of these operation lattices achieve ideal quasi achromat condition, they have certain relevant features. It is observed that fewer resonances aremore » present in the nominal operation lattice which is most close to quasi achromat required conditions.« less
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Designing and Conducting Strong Quasi-Experiments in Education. Version 2
ERIC Educational Resources Information Center
Scher, Lauren; Kisker, Ellen; Dynarski, Mark
2015-01-01
The purpose of this paper is to describe best practices in designing and implementing strong quasi-experimental designs (QED) when assessing the effectiveness of policies, programs or practices. The paper first discusses the issues researchers face when choosing to conduct a QED, as opposed to a more rigorous randomized controlled trial design.…
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Design of a 9-loop quasi-exponential waveform generator
NASA Astrophysics Data System (ADS)
Banerjee, Partha; Shukla, Rohit; Shyam, Anurag
2015-12-01
We know in an under-damped L-C-R series circuit, current follows a damped sinusoidal waveform. But if a number of sinusoidal waveforms of decreasing time period, generated in an L-C-R circuit, be combined in first quarter cycle of time period, then a quasi-exponential nature of output current waveform can be achieved. In an L-C-R series circuit, quasi-exponential current waveform shows a rising current derivative and thereby finds many applications in pulsed power. Here, we have described design and experiment details of a 9-loop quasi-exponential waveform generator. In that, design details of magnetic switches have also been described. In the experiment, output current of 26 kA has been achieved. It has been shown that how well the experimentally obtained output current profile matches with the numerically computed output.
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Design of a 9-loop quasi-exponential waveform generator.
Banerjee, Partha; Shukla, Rohit; Shyam, Anurag
2015-12-01
We know in an under-damped L-C-R series circuit, current follows a damped sinusoidal waveform. But if a number of sinusoidal waveforms of decreasing time period, generated in an L-C-R circuit, be combined in first quarter cycle of time period, then a quasi-exponential nature of output current waveform can be achieved. In an L-C-R series circuit, quasi-exponential current waveform shows a rising current derivative and thereby finds many applications in pulsed power. Here, we have described design and experiment details of a 9-loop quasi-exponential waveform generator. In that, design details of magnetic switches have also been described. In the experiment, output current of 26 kA has been achieved. It has been shown that how well the experimentally obtained output current profile matches with the numerically computed output.
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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.
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Holgado-Tello, Fco P; Chacón-Moscoso, Salvador; Sanduvete-Chaves, Susana; Pérez-Gil, José A
2016-01-01
The Campbellian tradition provides a conceptual framework to assess threats to validity. On the other hand, different models of causal analysis have been developed to control estimation biases in different research designs. However, the link between design features, measurement issues, and concrete impact estimation analyses is weak. In order to provide an empirical solution to this problem, we use Structural Equation Modeling (SEM) as a first approximation to operationalize the analytical implications of threats to validity in quasi-experimental designs. Based on the analogies established between the Classical Test Theory (CTT) and causal analysis, we describe an empirical study based on SEM in which range restriction and statistical power have been simulated in two different models: (1) A multistate model in the control condition (pre-test); and (2) A single-trait-multistate model in the control condition (post-test), adding a new mediator latent exogenous (independent) variable that represents a threat to validity. Results show, empirically, how the differences between both the models could be partially or totally attributed to these threats. Therefore, SEM provides a useful tool to analyze the influence of potential threats to validity.
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Holgado-Tello, Fco. P.; Chacón-Moscoso, Salvador; Sanduvete-Chaves, Susana; Pérez-Gil, José A.
2016-01-01
The Campbellian tradition provides a conceptual framework to assess threats to validity. On the other hand, different models of causal analysis have been developed to control estimation biases in different research designs. However, the link between design features, measurement issues, and concrete impact estimation analyses is weak. In order to provide an empirical solution to this problem, we use Structural Equation Modeling (SEM) as a first approximation to operationalize the analytical implications of threats to validity in quasi-experimental designs. Based on the analogies established between the Classical Test Theory (CTT) and causal analysis, we describe an empirical study based on SEM in which range restriction and statistical power have been simulated in two different models: (1) A multistate model in the control condition (pre-test); and (2) A single-trait-multistate model in the control condition (post-test), adding a new mediator latent exogenous (independent) variable that represents a threat to validity. Results show, empirically, how the differences between both the models could be partially or totally attributed to these threats. Therefore, SEM provides a useful tool to analyze the influence of potential threats to validity. PMID:27378991
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Evaluating the Cooperative Component in Cooperative Learning: A Quasi-Experimental Study
ERIC Educational Resources Information Center
Emerson, Tisha L. N.; English, Linda K.; McGoldrick, KimMarie
2015-01-01
In this study, the authors employed a quasi-experimental research design to examine the efficacy of a cooperative learning pedagogy (i.e., think-pair-share exercises) integrated into sections of microeconomic principles. Materials, exercises, and assessment instruments for all study sections are identical except for the nature of the…
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Promoting Healthy Eating in Nursery Schoolchildren: A Quasi-Experimental Intervention Study
ERIC Educational Resources Information Center
Korwanich, Kanyarat; Sheiham, Aubrey; Srisuphan, Wichit; Srisilapanan, Patcharawan
2008-01-01
Objective: To evaluate the effects of implementing a healthy eating policy on nursery schoolchildren's dietary practices in nurseries in Phrae Province, Thailand. Design: Quasi-experimental action research was used to compare the effects of school healthy eating policy on the diets of nursery schoolchildren in eight intervention and eight matched…
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Activating schoolyards: study design of a quasi-experimental schoolyard intervention study.
Andersen, Henriette Bondo; Pawlowski, Charlotte Skau; Scheller, Hanne Bebendorf; Troelsen, Jens; Toftager, Mette; Schipperijn, Jasper
2015-05-31
The aim of the Activating Schoolyards Study is to develop, implement, document and assess a comprehensive schoolyard intervention to promote physical activity (PA) during school recess for primary school children (grade 4-8). The intervention is designed to implement organizational and structural changes in the physical environment. The study builds on a quasi-experimental study design using a mixed method approach including: 1) an exploratory study aimed at providing input for the developing process; 2) an evaluation of the effect of the interventions using a combination of accelerometer, GPS and GIS; 3) a process evaluation facilitating the intervention development process and identifying barriers and facilitators in the implementation process; 4) a post-intervention end-user evaluation aimed at exploring who uses the schoolyards and how the schoolyards are used. The seven project schools (cases) were selected by means of an open competition and the interventions were developed using a participatory bottom-up approach. The participatory approach and case selection strategy make the study design novel. The use of a mixed methods design including qualitative as well as quantitative methods can be seen as a strength, as the different types of data complement each other and results of one part of the study informed the following parts. A unique aspect of our study is the use of accelerometers in combination with GPS and GIS in the effect evaluation to objectively determine where and how active the students are in the schoolyard, before and after the intervention. This provides a type of data that, to our knowledge, has not been used before in schoolyard interventions. Exploring the change in behavior in relation to specific intervention elements in the schoolyard will lead to recommendations for schools undergoing schoolyard renovations at some point in the future.
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South Korean military service promotes smoking: a quasi-experimental design.
Allem, Jon-Patrick; Ayers, John W; Irvin, Veronica L; Hofstetter, C Richard; Hovell, Melbourne F
2012-03-01
The South Korean (SK) government monopolizes the tobacco industry and is accused of pushing smoking on captive military personnel. However, estimating the association between military service and smoking is difficult, since military service is required for all SK men and the few civilian waivers are usually based on smoking determinants, e.g., social status. Using a quasi-experimental design we validly estimate the association between military service and smoking. Military service was assigned by immigration patterns to the United States, instead of an experimenter, by comparing Korean Americans who happened to immigrate before or after the age(s) of mandated service. Smoking promotion in the military was also described among SK veterans, to identify the probable mechanisms for veterans' smoking tendencies. Veterans were 15% [95% confidence interval (CI), 4 to 27] more likely to ever-puff and 10% (95% CI, 0 to 23) more likely to ever-smoke cigarettes, compared to a similar group of civilians. Among veterans, 92% (95% CI, 89 to 95) recalled cigarettes were free, 30% (95% CI, 25 to 35) recalled smokers were given more work breaks and 38% (95% CI, 32 to 43) felt explicit "social pressure" to smoke. Free cigarettes was the strongest mechanism for veterans' smoking tendencies, e.g., veterans recalling free cigarette distribution were 16% (95% CI, 1 to 37) more likely to ever-smoke than veterans not recalling. These patterns suggest military service is strongly associated with smoking, and differences between veterans and civilians smoking may carry over long after military service. Given military service remains entirely in government purview, actively changing military smoking policies may prove most efficacious. This highlights the importance of recent bans on military cigarette distribution, but policies eliminating other smoking encouragements described by veterans are necessary and could effectively reduce the smoking prevalence by as much as 10% in SK.
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Dijkstra, Arie; Zuidema, Rixt; Vos, Diederick; van Kalken, Marike
2014-09-13
The Allen Carr training (ACt) is a popular one-session smoking cessation group training that is provided by licensed organizations that have the permission to use the Allen Carr method. However, few data are available on the effectiveness of the training. In a quasi-experimental design the effects of the existing practice of providing the ACt to smokers (n = 124) in companies on abstinence, were compared to changes in abstinence in a cohort of similar smokers in the general population (n = 161). To increase comparability of the smokers in both conditions, smokers in the control condition were matched on the group level on baseline characteristics (fourteen variables) to the smokers in the ACt. The main outcome measure was self-reported continuous abstinence after 13 months, which was validated using a CO measurement in the Act condition. Logistic regression analyses showed that when baseline characteristics were comparable, significantly more responding smokers were continuously abstinent in the ACt condition compared to the control condition, Exp(B) = 6.52 (41.1% and 9.6%, respectively). The all-cases analysis was also significant, Exp(B) = 5.09 (31.5% and 8.3%, respectively). Smokers following the ACt in their company were about 6 times more likely to be abstinent, assessed after 13 months, compared to similar smokers in the general population. Although smokers in both conditions did not differ significantly on 14 variables that might be related to cessation success, the quasi-experimental design allows no definite conclusion about the effectiveness of the ACt. Still, these data support the provision of the ACt in companies.
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ERIC Educational Resources Information Center
Little, Priscilla M. D.; Harris, Erin
As the amount of resources allocated to out-of-school (OST) programming and policymakers' demands for research-based results increase, there is increasing interest in rigorous research designs to examine OST program outcomes. This issue of "Out-of-School Time Evaluation Snapshots" reviews 27 quasi-experimental and experimental OST…
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Belt restraint reduction in nursing homes: design of a quasi-experimental study.
Gulpers, Math J M; Bleijlevens, Michel H C; van Rossum, Erik; Capezuti, Elizabeth; Hamers, Jan P H
2010-02-25
The use of physical restraints still is common practice in the nursing home care. Since physical restraints have been shown to be an ineffective and sometimes even hazardous measure, interventions are needed to reduce their usage. Several attempts have been made to reduce the use of physical restraints. Most studies used educational approaches and introduced a nurse specialist as a consultant. However, the success rate of these interventions has been inconsistent. We developed a new multi-component intervention (EXBELT) comprising an educational intervention for nursing home staff in combination with a policy change (belt use is prohibited by the nursing home management), availability of a nurse specialist and nursing home manager as consultants, and availability of alternative interventions. The first aim of this study is to further develop and test the effectiveness of EXBELT on belt restraint reduction in Dutch psychogeriatric nursing homes. However, the reduction of belts should not result in an increase of other restrictive restraints (such as a chair with locked tray table) or psychoactive drug use. The overall aim is an effective and feasible intervention that can be employed on a large scale in Dutch nursing homes. Effects of EXBELT will be studied in a quasi-experimental longitudinal study design. Alongside the effect evaluation, a process evaluation will be carried out in order to further develop EXBELT. Data regarding age, gender, use of physical restraints, the number of falls and fall related injuries, psychoactive drug use, and the use of alternative interventions will be collected at baseline and after four and eight months of follow-up. Data regarding the process evaluation will be gathered in a period of eight months between baseline and the last measurement. Furthermore, changing attitudes will become an important addition to the educational part of EXBELT. A quasi-experimental study is presented to investigate the effects of EXBELT on the use of
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Becker, Betsy Jane; Aloe, Ariel M; Duvendack, Maren; Stanley, T D; Valentine, Jeffrey C; Fretheim, Atle; Tugwell, Peter
2017-09-01
To outline issues of importance to analytic approaches to the synthesis of quasi-experiments (QEs) and to provide a statistical model for use in analysis. We drew on studies of statistics, epidemiology, and social-science methodology to outline methods for synthesis of QE studies. The design and conduct of QEs, effect sizes from QEs, and moderator variables for the analysis of those effect sizes were discussed. Biases, confounding, design complexities, and comparisons across designs offer serious challenges to syntheses of QEs. Key components of meta-analyses of QEs were identified, including the aspects of QE study design to be coded and analyzed. Of utmost importance are the design and statistical controls implemented in the QEs. Such controls and any potential sources of bias and confounding must be modeled in analyses, along with aspects of the interventions and populations studied. Because of such controls, effect sizes from QEs are more complex than those from randomized experiments. A statistical meta-regression model that incorporates important features of the QEs under review was presented. Meta-analyses of QEs provide particular challenges, but thorough coding of intervention characteristics and study methods, along with careful analysis, should allow for sound inferences. Copyright © 2017 Elsevier Inc. All rights reserved.
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D’Onofrio, Brian M.; Class, Quetzal A.; Lahey, Benjamin B.; Larsson, Henrik
2014-01-01
The Developmental Origin of Health and Disease (DOHaD) hypothesis is a broad theoretical framework that emphasizes how early risk factors have a causal influence on psychopathology. Researchers have raised concerns about the causal interpretation of statistical associations between early risk factors and later psychopathology because most existing studies have been unable to rule out the possibility of environmental and genetic confounding. In this paper we illustrate how family-based quasi-experimental designs can test the DOHaD hypothesis by ruling out alternative hypotheses. We review the logic underlying sibling-comparison, co-twin control, offspring of siblings/twins, adoption, and in vitro fertilization designs. We then present results from studies using these designs focused on broad indices of fetal development (low birth weight and gestational age) and a particular teratogen, smoking during pregnancy. The results provide mixed support for the DOHaD hypothesis for psychopathology, illustrating the critical need to use design features that rule out unmeasured confounding. PMID:25364377
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Zeeman, Heidi; Kendall, Elizabeth; Whitty, Jennifer A; Wright, Courtney J; Townsend, Clare; Smith, Dianne; Lakhani, Ali; Kennerley, Samantha
2016-03-15
Identifying the housing preferences of people with complex disabilities is a much needed, but under-developed area of practice and scholarship. Despite the recognition that housing is a social determinant of health and quality of life, there is an absence of empirical methodologies that can practically and systematically involve consumers in this complex service delivery and housing design market. A rigorous process for making effective and consistent development decisions is needed to ensure resources are used effectively and the needs of consumers with complex disability are properly met. This 3-year project aims to identify how the public and private housing market in Australia can better respond to the needs of people with complex disabilities whilst simultaneously achieving key corporate objectives. First, using the Customer Relationship Management framework, qualitative (Nominal Group Technique) and quantitative (Discrete Choice Experiment) methods will be used to quantify the housing preferences of consumers and their carers. A systematic mixed-method, quasi-experimental design will then be used to quantify the development priorities of other key stakeholders (e.g., architects, developers, Government housing services etc.) in relation to inclusive housing for people with complex disabilities. Stakeholders randomly assigned to Group 1 (experimental group) will participate in a series of focus groups employing Analytical Hierarchical Process (AHP) methodology. Stakeholders randomly assigned to Group 2 (control group) will participate in focus groups employing existing decision making processes to inclusive housing development (e.g., Risk, Opportunity, Cost, Benefit considerations). Using comparative stakeholder analysis, this research design will enable the AHP methodology (a proposed tool to guide inclusive housing development decisions) to be tested. It is anticipated that the findings of this study will enable stakeholders to incorporate consumer housing
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Quasi-Experimental Evaluation of a National Primary School HIV Intervention in Kenya
ERIC Educational Resources Information Center
Maticka-Tyndale, Eleanor; Wildish, Janet; Gichuru, Mary
2007-01-01
This study examined the impact of a primary-school HIV education initiative on the knowledge, self-efficacy and sexual and condom use activities of upper primary-school pupils in Kenya. A quasi-experimental mixed qualitative-quantitative pre- and 18-month post-design using 40 intervention and 40 matched control schools demonstrated significant…
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The effects of survey question wording on rape estimates: evidence from a quasi-experimental design.
Fisher, Bonnie S
2009-02-01
The measurement of rape is among the leading methodological issues in the violence against women field. Methodological discussion continues to focus on decreasing measurement errors and improving the accuracy of rape estimates. The current study used a quasi-experimental design to examine the effect of survey question wording on estimates of completed and attempted rape and verbal threats of rape. Specifically, the study statistically compares self-reported rape estimates from two nationally representative studies of college women's sexual victimization experiences, the National College Women Sexual Victimization study and the National Violence Against College Women study. Results show significant differences between the two sets of rape estimates, with National Violence Against College Women study rape estimates ranging from 4.4% to 10.4% lower than the National College Women Sexual Victimization study rape estimates. Implications for future methodological research are discussed.
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Concurrent design of quasi-random photonic nanostructures
Lee, Won-Kyu; Yu, Shuangcheng; Engel, Clifford J.; Reese, Thaddeus; Rhee, Dongjoon; Chen, Wei
2017-01-01
Nanostructured surfaces with quasi-random geometries can manipulate light over broadband wavelengths and wide ranges of angles. Optimization and realization of stochastic patterns have typically relied on serial, direct-write fabrication methods combined with real-space design. However, this approach is not suitable for customizable features or scalable nanomanufacturing. Moreover, trial-and-error processing cannot guarantee fabrication feasibility because processing–structure relations are not included in conventional designs. Here, we report wrinkle lithography integrated with concurrent design to produce quasi-random nanostructures in amorphous silicon at wafer scales that achieved over 160% light absorption enhancement from 800 to 1,200 nm. The quasi-periodicity of patterns, materials filling ratio, and feature depths could be independently controlled. We statistically represented the quasi-random patterns by Fourier spectral density functions (SDFs) that could bridge the processing–structure and structure–performance relations. Iterative search of the optimal structure via the SDF representation enabled concurrent design of nanostructures and processing. PMID:28760975
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2010-01-01
Social isolation and disengagement fragments local communities. Evidence indicates that refugee families are highly vulnerable to social isolation in their countries of resettlement. Research to identify approaches to best address this is needed. Football United is a program that aims to foster social inclusion and cohesion in areas with high refugee settlement in New South Wales, Australia, through skills and leadership development, mentoring, and the creation of links with local community and corporate leaders and organisations. The Social Cohesion through Football study's broad goal is to examine the implementation of a complex health promotion program, and to analyse the processes involved in program implementation. The study will consider program impact on individual health and wellbeing, social inclusion and cohesion, as well as analyse how the program by necessity interacts and adapts to context during implementation, a concept we refer to as plasticity. The proposed study will be the first prospective cohort impact study to our knowledge to assess the impact of a comprehensive integrated program using football as a vehicle for fostering social inclusion and cohesion in communities with high refugee settlement. Methods/design A quasi-experimental cohort study design with treatment partitioning involving four study sites. The study employs a 'dose response' model, comparing those with no involvement in the Football United program with those with lower or higher levels of participation. A range of qualitative and quantitative measures will be used in the study. Study participants' emotional well being, resilience, ethnic identity and other group orientation, feelings of social inclusion and belonging will be measured using a survey instrument complemented by relevant data drawn from in-depth interviews, self reporting measures and participant observation. The views of key informants from the program and the wider community will also be solicited. Discussion
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ERIC Educational Resources Information Center
Eggleston, Jessica
2017-01-01
Elementary students spend an average of five and a quarter hours per day seated on a hard surface which provides little sensory input and possibly contributes to discomfort. Sensory integration was found to improve executive functioning skills in elementary students by helping their comfort level at being seated. This quasi-experimental study…
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Verbeek, Hilde; van Rossum, Erik; Zwakhalen, Sandra M G; Ambergen, Ton; Kempen, Gertrudis I J M; Hamers, Jan P H
2009-01-20
Small-scale and homelike facilities for older people with dementia are rising in current dementia care. In these facilities, a small number of residents live together and form a household with staff. Normal, daily life and social participation are emphasized. It is expected that these facilities improve residents' quality of life. Moreover, it may have a positive influence on staff's job satisfaction and families involvement and satisfaction with care. However, effects of these small-scale and homelike facilities have hardly been investigated. Since the number of people with dementia increases, and institutional long-term care is more and more organized in small-scale and homelike facilities, more research into effects is necessary. This paper presents the design of a study investigating effects of small-scale living facilities in the Netherlands on residents, family caregivers and nursing staff. A longitudinal, quasi-experimental study is carried out, in which 2 dementia care settings are compared: small-scale living facilities and regular psychogeriatric wards in traditional nursing homes. Data is collected from residents, their family caregivers and nursing staff at baseline and after 6 and 12 months of follow-up. Approximately 2 weeks prior to baseline measurement, residents are screened on cognition and activities of daily living (ADL). Based on this screening profile, residents in psychogeriatric wards are matched to residents living in small-scale living facilities. The primary outcome measure for residents is quality of life. In addition, neuropsychiatric symptoms, depressive symptoms and social engagement are assessed. Involvement with care, perceived burden and satisfaction with care provision are primary outcome variables for family caregivers. The primary outcomes for nursing staff are job satisfaction and motivation. Furthermore, job characteristics social support, autonomy and workload are measured. A process evaluation is performed to investigate to
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Nathan, Sally; Bunde-Birouste, Anne; Evers, Clifton; Kemp, Lynn; MacKenzie, Julie; Henley, Robert
2010-10-05
Social isolation and disengagement fragments local communities. Evidence indicates that refugee families are highly vulnerable to social isolation in their countries of resettlement. Research to identify approaches to best address this is needed. Football United is a program that aims to foster social inclusion and cohesion in areas with high refugee settlement in New South Wales, Australia, through skills and leadership development, mentoring, and the creation of links with local community and corporate leaders and organisations. The Social Cohesion through Football study's broad goal is to examine the implementation of a complex health promotion program, and to analyse the processes involved in program implementation. The study will consider program impact on individual health and wellbeing, social inclusion and cohesion, as well as analyse how the program by necessity interacts and adapts to context during implementation, a concept we refer to as plasticity. The proposed study will be the first prospective cohort impact study to our knowledge to assess the impact of a comprehensive integrated program using football as a vehicle for fostering social inclusion and cohesion in communities with high refugee settlement. A quasi-experimental cohort study design with treatment partitioning involving four study sites. The study employs a 'dose response' model, comparing those with no involvement in the Football United program with those with lower or higher levels of participation. A range of qualitative and quantitative measures will be used in the study. Study participants' emotional well being, resilience, ethnic identity and other group orientation, feelings of social inclusion and belonging will be measured using a survey instrument complemented by relevant data drawn from in-depth interviews, self reporting measures and participant observation. The views of key informants from the program and the wider community will also be solicited. The complexity of the
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Yu, Mi; Kang, Kyung Ja
2017-06-01
Accurate, skilled communication in handover is of high priority in maintaining patients' safety. Nursing students have few chances to practice nurse-to-doctor handover in clinical training, and some have little knowledge of what constitutes effective handover or lack confidence in conveying information. This study aimed to develop a role-play simulation program involving the Situation, Background, Assessment, Recommendation technique for nurse-to-doctor handover; implement the program; and analyze its effects on situation, background, assessment, recommendation communication, communication clarity, handover confidence, and education satisfaction in nursing students. Non-equivalent control-group pretest-posttest quasi-experimental. A convenience sample of 62 senior nursing students from two Korean universities. The differences in SBAR communication, communication clarity, handover confidence, and education satisfaction between the control and intervention groups were measured before and after program participation. The intervention group showed higher Situation, Background, Assessment, Recommendation communication scores (t=-3.05, p=0.003); communication clarity scores in doctor notification scenarios (t=-5.50, p<0.001); and Situation, Background, Assessment, Recommendation education satisfaction scores (t=-4.94, p<0.001) relative to those of the control group. There was no significant difference in handover confidence between groups (t=-1.97, p=0.054). The role-play simulation program developed in this study could be used to promote communication skills in nurse-to-doctor handover and cultivate communicative competence in nursing students. Copyright © 2017. Published by Elsevier Ltd.
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A Study of the Generalizability of Teacher Change Quasi-Experiments
ERIC Educational Resources Information Center
Stringfield, Samuel; Schaffer, Eugene; Devlin-Scherer, Roberta
2017-01-01
Quasi-experimental teacher effectiveness studies have indicated that properly designed staff development programs can lead to changes in teacher and student behavior and to gains in student achievement. Those studies involved workshop series led by nationally known scholars. Using instructors from varied backgrounds, the current study examined the…
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Wang, Jeng; Chen, Chu-Yeh; Lai, Li-Ju; Chen, Min-Li; Chen, Mei-Yen
2014-08-01
A community-based health promotion program (CBHP) might be beneficial for the elderly, but evidence is limited. We therefore examined the effect of a CBHP on change of lifestyle, physiological indicators and depression score among seniors in 2 rural areas. A prospective quasi-experimental design involved a total of 520 senior participants living in 6 rural villages, who were clustered and conveniently assigned to 2 intervention groups. Senior nursing students were the interveners for group 1 and community peer supporters for group 2. The primary outcome measure was the change in health-related behavior measured on the geriatric health promotion scale (GHPS). The secondary outcome comprised changes in the short form of the Chinese geriatric depression scale (CGDS-15), fasting blood sugar, total cholesterol, waist circumference and blood pressure. Paired-t test and analysis of covariance were used for statistical inspection. Most of the participants were retired farmers or fishermen >75years of age who had little education. The total scores and all subscales of GHPS, along with some physiological indicators, improved significantly between pretest and post-test in both groups. After adjustment for confounders, intervention in group 1 was more effective than that in group 2 regarding self-protection behaviors. Systolic and diastolic blood pressure was significantly lower in group 2. CBHP programs are valuable for improving healthy lifestyle, fasting blood sugar, blood pressure and depression score among seniors. The low cost and effectiveness of incorporating multidisciplinary resources to help rural elders to maintain a healthy status and a healthier lifestyle. Copyright © 2014 Elsevier Inc. All rights reserved.
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Quasi-experimental evaluation without regression analysis.
Rohrer, James E
2009-01-01
Evaluators of public health programs in field settings cannot always randomize subjects into experimental or control groups. By default, they may choose to employ the weakest study design available: the pretest, posttest approach without a comparison group. This essay argues that natural experiments involving comparison groups are within reach of public health program managers. Methods for analyzing natural experiments are discussed.
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Surgenor, Paul Wg; Freeman, Joan; O'Connor, Cindy
2015-01-01
While most crisis intervention models adhere to a generalised theoretical framework, the lack of clarity around how these should be enacted has resulted in a proliferation of models, most of which have little to no empirical support. The primary aim of this research was to propose a suicide intervention model that would resolve the client's suicidal crisis by decreasing their suicidal ideation and improve their outlook through enhancing a range of protective factors. The secondary aim was to assess the impact of this model on negative and positive outlook. A quasi-experimental, pre-test post-test repeated measures design was employed. A questionnaire assessing self-esteem, depression, and positive and negative suicidal ideation was administered to the same participants pre- and post- therapy facilitating paired responses. Multiple analysis of variance and paired-samples t-tests were conducted to establish whether therapy using the PH-SIM had a significant effect on the clients' negative and positive outlook. Analyses revealed a statistically significant effect of therapy for depression, negative suicidal ideation, self-esteem, and positive suicidal ideation. Negative outlook was significantly lower after therapy and positive outlook significantly higher. The decreased negative outlook and increased positive outlook following therapy provide some support for the proposed model in fulfilling its role, though additional research is required to establish the precise role of the intervention model in achieving this.
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NASA Astrophysics Data System (ADS)
Zhu, Ning; Sun, Shou-Guang; Li, Qiang; Zou, Hua
2014-12-01
One of the major problems in structural fatigue life analysis is establishing structural load spectra under actual operating conditions. This study conducts theoretical research and experimental validation of quasi-static load spectra on bogie frame structures of high-speed trains. The quasistatic load series that corresponds to quasi-static deformation modes are identified according to the structural form and bearing conditions of high-speed train bogie frames. Moreover, a force-measuring frame is designed and manufactured based on the quasi-static load series. The load decoupling model of the quasi-static load series is then established via calibration tests. Quasi-static load-time histories, together with online tests and decoupling analysis, are obtained for the intermediate range of the Beijing—Shanghai dedicated passenger line. The damage consistency calibration of the quasi-static discrete load spectra is performed according to a damage consistency criterion and a genetic algorithm. The calibrated damage that corresponds with the quasi-static discrete load spectra satisfies the safety requirements of bogie frames.
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Design of Quasi-Terminator Orbits near Primitive Bodies
NASA Technical Reports Server (NTRS)
Lantoine, Gregory; Broschart, Stephen B.; Grebow, Daniel J.
2013-01-01
Quasi-terminator orbits are a class of quasi-periodic orbits around a primitive body that exist in the vicinity of the well-known terminator orbits. The inherent stability of quasi-terminator trajectories and their wide variety of viewing geometries make them a very compelling option for primitive body mapping missions. In this paper, we discuss orbit design methodologies for selection of an appropriate quasi-terminator orbit that would meet the needs of a specific mission. Convergence of these orbits in an eccentric, higher-fidelity model is also discussed with an example case at Bennu, the target of the upcoming NASA's OSIRIS-REx mission.
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Quasi-symmetric designs and equiangular tight frames
NASA Astrophysics Data System (ADS)
Fickus, Matthew; Jasper, John; Mixon, Dustin; Peterson, Jesse
2015-08-01
An equiangular tight frame (ETF) is an M×N matrix which has orthogonal equal norm rows, equal norm columns, and the inner products of all pairs of columns have the same modulus. ETFs arise in numerous applications, including compressed sensing. They also seem to be rare: despite over a decade of active research by the community, only a few construction methods have been discovered. In this article we introduce a new construction of ETFs which uses a particular set of combinatorial designs called quasi-symmetric designs. For ETFs whose entries are contained in {+1;-1}, called real constant amplitude ETFs (RCAETFs), we see that this construction is reversible, giving new quasi-symmetric designs from the known constructions RCAETFs.
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Fletcher, Jason M
2014-01-01
This article uses a gene-environment interaction framework to examine the differential responses to an objective external stressor based on genetic variation in the production of depressive symptoms. This article advances the literature by utilizing a quasi-experimental environmental exposure design, as well as a regression discontinuity design, to control for seasonal trends, which limit the potential for gene-environment correlation and allow stronger causal claims. Replications are attempted for two prominent genes (5-HTT and MAOA), and three additional genes are explored (DRD2, DRD4, and DAT1). This article provides evidence of a main effect of 9/11 on reports of feelings of sadness and fails to replicate a common finding of interaction using 5-HTT but does show support for interaction with MAOA in men. It also provides new evidence that variation in the DRD4 gene modifies an individual's response to the exposure, with individuals with no 7-repeats found to have a muted response.
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Quasi-static Design of Electrically Small Ultra-Wideband Antennas
2017-02-01
this design reduces the width of the antenna, which implies that the bulb shape can be non -spherical at high frequencies. The stored energy in an...conclusion. The Quasi-static Antenna Design Algorithm generates three UWB non -spherical bulb shapes. The non -spherical bulb shape performs as well...TECHNICAL REPORT 3056 February 2017 Quasi-static Design of Electrically Small Ultra-Wideband Antennas Thomas O. Jones III Approved for public
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ERIC Educational Resources Information Center
Varnell, Matt
2013-01-01
The purpose of this study was to evaluate the effect of rhythm and tonality on an academic memory task by comparing three different treatment conditions: a poem, a rhythmic chant (or rap), and a melodic rhythm (or song). A quasi-experimental experiment was designed and implemented, specifically a pretest-posttest-posttest control-group design.…
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Law, Yik-Wa; Yip, Paul S F; Lai, Carmen C S; Kwok, Chi Leung; Wong, Paul W C; Liu, Kwong-Sun; Ng, Pauline W L; Liao, Carmen W M; Wong, Tai-Wai
2016-11-01
Studies have shown that postdischarge care for self-harm patients is effective in reducing repeated suicidal behaviors. Little is known about whether volunteer support can help reduce self-harm repetition and improve psychosocial well-being. This study investigated the efficacy of volunteer support in preventing repetition of self-harm. This study used a quasi-experimental design by assigning self-harm patients admitted to the emergency departments to an intervention group with volunteer support and treatment as usual (TAU) for 9 months and to a control group of TAU. Outcome measures include repetition of self-harm, suicidal ideation, hopelessness, and level of depressive and anxiety symptoms. A total of 74 cases were recruited (38 participants; 36 controls). There were no significant differences in age, gender, and clinical condition between the two groups at the baseline. The intervention group showed significant improvements in hopelessness and depressive symptoms. However, the number of cases of suicide ideation and of repetition of self-harm episodes was similar for both groups at the postintervention period. Postdischarge care provided by volunteers showed significant improvement in hopelessness and depression. Volunteers have been commonly involved in suicide prevention services. Further research using rigorous methods is recommended for improving service quality in the long term.
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The impact of retirement on health: quasi-experimental methods using administrative data.
Horner, Elizabeth Mokyr; Cullen, Mark R
2016-02-19
Is retirement good or bad for health? Disentangling causality is difficult. Much of the previous quasi-experimental research on the effect of health on retirement used self-reported health and relied upon discontinuities in public retirement incentives across Europe. The current study investigated the effect of retirement on health by exploiting discontinuities in private retirement incentives to test the effect of retirement on health using a quasi-experimental study design. Secondary data (1997-2009) on a cohort of male manufacturing workers in a United States setting. Health status was determined using claims data from private insurance and Medicare. Analyses used employer-based administrative and claims data and claim data from Medicare. Widely used selection on observables models overstate the negative impact of retirement due to the endogeneity of the decision to retire. In addition, health status as measured by administrative claims data provide some advantages over the more commonly used survey items. Using an instrument and administrative health records, we find null to positive effects from retirement on all fronts, with a possible exception of increased risk for diabetes. This study provides evidence that retirement is not detrimental and may be beneficial to health for a sample of manufacturing workers. In addition, it supports previous research indicating that quasi-experimental methodologies are necessary to evaluate the relationship between retirement and health, as any selection on observable model will overstate the negative relationship of retirement on health. Further, it provides a model for how such research could be implemented in countries like the United States that do not have a strong public pension program. Finally, it demonstrates that such research need-not rely upon survey data, which has certain shortcomings and is not always available for homogenous samples.
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ERIC Educational Resources Information Center
Olejnik, Stephen
The measurement of change in quasi-experimental educational research was discussed. Problems related to measuring change exist to varying degrees in all research designs; these issues are less troublesome in experimental studies because the investigator can manipulate the interest variables and observe their effects on other variables. Measuring…
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ERIC Educational Resources Information Center
Reber, Jeffrey S.; Downs, Samuel D.; Peterson Nelson, Julie A.
2017-01-01
This study employed a quasi-experimental design to test the effects of three pedagogies on learning outcomes in a simulated psychology of gender lecture. Results showed that meaning and relational pedagogies, as well as a combination of meaning, relational, and explanatory pedagogies, significantly improved participant learning beyond self-study…
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Early-Life Nutritional Programming of Type 2 Diabetes: Experimental and Quasi-Experimental Evidence.
Vaiserman, Alexander M
2017-03-05
Consistent evidence from both experimental and human studies suggest that inadequate nutrition in early life can contribute to risk of developing metabolic disorders including type 2 diabetes (T2D) in adult life. In human populations, most findings supporting a causative relationship between early-life malnutrition and subsequent risk of T2D were obtained from quasi-experimental studies ('natural experiments'). Prenatal and/or early postnatal exposures to famine were demonstrated to be associated with higher risk of T2D in many cohorts around the world. Recent studies have highlighted the importance of epigenetic regulation of gene expression as a possible major contributor to the link between the early-life famine exposure and T2D in adulthood. Findings from these studies suggest that prenatal exposure to the famine may result in induction of persistent epigenetic changes that have adaptive significance in postnatal development but can predispose to metabolic disorders including T2D at the late stages of life. In this review, quasi-experimental data on the developmental programming of T2D are summarized and recent research findings on changes in DNA methylation that mediate these effects are discussed.
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Early-Life Nutritional Programming of Type 2 Diabetes: Experimental and Quasi-Experimental Evidence
Vaiserman, Alexander M.
2017-01-01
Consistent evidence from both experimental and human studies suggest that inadequate nutrition in early life can contribute to risk of developing metabolic disorders including type 2 diabetes (T2D) in adult life. In human populations, most findings supporting a causative relationship between early-life malnutrition and subsequent risk of T2D were obtained from quasi-experimental studies (‘natural experiments’). Prenatal and/or early postnatal exposures to famine were demonstrated to be associated with higher risk of T2D in many cohorts around the world. Recent studies have highlighted the importance of epigenetic regulation of gene expression as a possible major contributor to the link between the early-life famine exposure and T2D in adulthood. Findings from these studies suggest that prenatal exposure to the famine may result in induction of persistent epigenetic changes that have adaptive significance in postnatal development but can predispose to metabolic disorders including T2D at the late stages of life. In this review, quasi-experimental data on the developmental programming of T2D are summarized and recent research findings on changes in DNA methylation that mediate these effects are discussed. PMID:28273874
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Of taps and toilets: quasi-experimental protocol for evaluating community-demand-driven projects.
Pattanayak, Subhrendu K; Poulos, Christine; Yang, Jui-Chen; Patil, Sumeet R; Wendland, Kelly J
2009-09-01
Sustainable and equitable access to safe water and adequate sanitation are widely acknowledged as vital, yet neglected, development goals. Water supply and sanitation (WSS) policies are justified because of the usual efficiency criteria, but also major equity concerns. Yet, to date there are few scientific impact evaluations showing that WSS policies are effective in delivering social welfare outcomes. This lack of an evaluation culture is partly because WSS policies are characterized by diverse mechanisms, broad goals and the increasing importance of decentralized delivery, and partly because programme administrators are unaware of appropriate methods. We describe a protocol for a quasi-experimental evaluation of a community-demand-driven programme for water and sanitation in rural India, which addresses several evaluation challenges. After briefly reviewing policy and implementation issues in the sector, we describe key features of our protocol, including control group identification, pre-post measurement, programme theory, sample sufficiency and robust indicators. At its core, our protocol proposes to combine propensity score matching and difference-in-difference estimation. We conclude by briefly summarizing how quasi-experimental impact evaluations can address key issues in WSS policy design and when such evaluations are needed.
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Training informal caregivers to care for older people after stroke: a quasi-experimental study.
Araújo, Odete; Lage, Isabel; Cabrita, José; Teixeira, Laetitia
2018-05-12
The present study aimed at evaluating whether training on practical skills involved in providing care reduces the burden experienced by informal caregivers and improves their general health condition. A substantial number of informal caregivers lack skills to deliver post-stroke assistance to older people after hospital discharge, which leads to burden situations as well as mental and physical health deterioration of the former. A quasi-experimental design. This study involved 174 informal caregivers of older people who overcame a stroke. The control group (N= 89) received the usual type of care delivered in healthcare units. The experimental group (N=85) adopted the InCARE programme for 1 week (T0), 1 month (T1) and 3 (T2) months and received telephone support by counselling caregivers on the subsequent 3rd, 6th, 8th and 10th weeks to hospital discharge. It aimed at facilitating the caregiver's adjustment to the demands of a post- stroke stage and at increasing knowledge and practical skills to support the decision making. Data collection occurred between February - December 2014 at the Community Home Care Services in northern Portugal. The experimental group obtained significantly better results regarding practical skills as well as lower burden levels and a better general mental health condition when compared with the control group 1 (T1) and 3 (T2) months after intervention. Findings suggest that our programme improved practical skills, helped reduce burden levels with better scores and improvement regarding general mental health condition of informal caregivers. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
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A Primer on Experimental and Quasi-experimental Design.
ERIC Educational Resources Information Center
Dawson, Thomas E.
Counseling psychology is a relatively new field that is gaining autonomy and respect. Unfortunately, research efforts in the field may lack an appropriate research design. This paper considers some of the more common types of research design and the associated threats to their validity. An example of each design type is drawn from the counseling…
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Shields, Linda; Zhou, Huaqiong; Taylor, Marjory; Hunter, Judith; Munns, Ailsa; Watts, Robin
Family-centred care is an approach to the planning, delivery, and evaluation of health care that is grounded in mutually beneficial partnerships among health care providers, patients, and families. It is a widely used model in paediatrics, and is felt instinctively to be the best way to provide care to children in hospital. However, its effectiveness has not been established. The objective of this review was to identify the effectiveness of family-centred models of care for children (excluding premature neonates) when compared to standard models of care. The review considered quasi-experimental studies of children aged 0-12 years, their families and/or attending health professionals. Interventions for inclusion were family-centred polices, family support, communication, educational and environmental. Outcomes of interest covered three categories: the child, parent and staff. These included psychological, behavioural, physical, developmental, knowledge, satisfaction and attitudinal outcomes. The degree of family-centredness for eligible studies was scored using a modified rating scale based on that developed by Trivette.This review considered studies that included hospitalised children aged 0-12 years (excluding premature neonates), their family and/or health care professionals.The review considered studies that evaluated the effectiveness of family-centred models of care for hospitalised children when compared to standard models of care.The review considered quasi-experimental studies for inclusion to enable the identification of current best evidence regarding the effectiveness of family-centred models of care on child, family and health service outcomes. Quasi-experimental design includes experimental studies in which participants are not randomly assigned to treatment conditions.This review considered studies that included the following outcome measures: SEARCH STRATEGY: The search strategy identified published and unpublished studies dated from 2004 to December
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Providing Guidance in Virtual Lab Experimentation: The Case of an Experiment Design Tool
ERIC Educational Resources Information Center
Efstathiou, Charalampos; Hovardas, Tasos; Xenofontos, Nikoletta A.; Zacharia, Zacharias C.; deJong, Ton; Anjewierden, Anjo; van Riesen, Siswa A. N.
2018-01-01
The present study employed a quasi-experimental design to assess a computer-based tool, which was intended to scaffold the task of designing experiments when using a virtual lab for the process of experimentation. In particular, we assessed the impact of this tool on primary school students' cognitive processes and inquiry skills before and after…
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Quasi-Experimental Analysis: A Mixture of Methods and Judgment.
ERIC Educational Resources Information Center
Cordray, David S.
1986-01-01
The role of human judgment in the development and synthesis of evidence has not been adequately developed or acknowledged within quasi-experimental analysis. Corrective solutions need to confront the fact that causal analysis within complex environments will require a more active assessment that entails reasoning and statistical modeling.…
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ERIC Educational Resources Information Center
Vincent, Claude; Lachance, Jean-Paul; Deaudelin, Isabelle
2012-01-01
This study sought to compare road safety of new drivers with low vision who have followed a specific pilot bioptic training program with other groups of drivers all matched for age and driving experience. A quasi-experimental design was used two years after drivers obtained their license. Drivers were classified in the experimental group (n = 10,…
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Learning with older people--Outcomes of a quasi-experimental study.
Koskinen, Sanna; Salminen, Leena; Puukka, Pauli; Leino-Kilpi, Helena
2016-02-01
Nursing students' interest in older people nursing needs to be enhanced, as there is a demand for competent nurses who prefer to work in older people nursing. Educational approaches involving older people are encouraging; they increase positive learning outcomes. The aim of this study was to evaluate the outcomes of the Learning with Older People Programme (LOPP) in terms of nursing students' interest in older people nursing, their attitudes towards older people and their knowledge level about ageing. A quasi-experimental, pre-post-test design with non-equivalent comparison group was used. Two different Finnish nursing schools geographically apart from each other. A nonprobability, convenience sample of nursing students (n=87; n=46 in the intervention group, n=41 in the comparison group) in the middle of their 3.5 year bachelor degree studies and enrolled in compulsory theoretical older people nursing courses participated in the study. Data were collected in 2014 using a structured questionnaire that included background questions, students' interest in older people nursing as a primary outcome measure and their attitudes towards older people and knowledge level about ageing as secondary outcome measures. The data were analysed statistically. In the intervention group, students' interest in older people nursing was significantly higher and their attitudes towards older people were more positive than those of students in the comparison group. There were no significant differences between the groups in terms of the students' knowledge level about ageing. An educational approach involving older people resulted in encouraging outcomes. It is worth considering whether or not older people could be a valuable resource for nursing education. Copyright © 2015 Elsevier Ltd. All rights reserved.
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Shen, Huixia; Edwards, Helen; Courtney, Mary; McDowell, Jan; Wu, Ming
2012-12-01
A protocol for a new peer-led self-management programme for community-dwelling older people with diabetes in Shanghai, China. The increasing prevalence of type 2 diabetes poses major public health challenges. Appropriate education programmes could help people with diabetes to achieve self-management and better health outcomes. Providing education programmes to the fast growing number of people with diabetes present a real challenge to Chinese healthcare system, which is strained for personnel and funding shortages. Empirical literature and expert opinions suggest that peer education programmes are promising. Quasi-experimental. This study is a non-equivalent control group design (protocol approved in January, 2008). A total of 190 people, with 95 participants in each group, will be recruited from two different, but similar, communities. The programme, based on Social Cognitive Theory, will consist of basic diabetes instruction and social support and self-efficacy enhancing group activities. Basic diabetes instruction sessions will be delivered by health professionals, whereas social support and self-efficacy enhancing group activities will be led by peer leaders. Outcome variables include: self-efficacy, social support, self-management behaviours, depressive status, quality of life and healthcare utilization, which will be measured at baseline, 4 and 12 weeks. This theory-based programme tailored to Chinese patients has potential for improving diabetes self-management and subsequent health outcomes. In addition, the delivery mode, through involvement of peer leaders and existing community networks, is especially promising considering healthcare resource shortage in China. © 2012 Blackwell Publishing Ltd.
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Dose-finding designs using a novel quasi-continuous endpoint for multiple toxicities
Ezzalfani, Monia; Zohar, Sarah; Qin, Rui; Mandrekar, Sumithra J; Deley, Marie-Cécile Le
2013-01-01
The aim of a phase I oncology trial is to identify a dose with an acceptable safety profile. Most phase I designs use the dose-limiting toxicity, a binary endpoint, to assess the unacceptable level of toxicity. The dose-limiting toxicity might be incomplete for investigating molecularly targeted therapies as much useful toxicity information is discarded. In this work, we propose a quasi-continuous toxicity score, the total toxicity profile (TTP), to measure quantitatively and comprehensively the overall severity of multiple toxicities. We define the TTP as the Euclidean norm of the weights of toxicities experienced by a patient, where the weights reflect the relative clinical importance of each grade and toxicity type. We propose a dose-finding design, the quasi-likelihood continual reassessment method (CRM), incorporating the TTP score into the CRM, with a logistic model for the dose–toxicity relationship in a frequentist framework. Using simulations, we compared our design with three existing designs for quasi-continuous toxicity score (the Bayesian quasi-CRM with an empiric model and two nonparametric designs), all using the TTP score, under eight different scenarios. All designs using the TTP score to identify the recommended dose had good performance characteristics for most scenarios, with good overdosing control. For a sample size of 36, the percentage of correct selection for the quasi-likelihood CRM ranged from 80% to 90%, with similar results for the quasi-CRM design. These designs with TTP score present an appealing alternative to the conventional dose-finding designs, especially in the context of molecularly targeted agents. PMID:23335156
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Narrative Enhancement and Cognitive Therapy (NECT) Effectiveness: A Quasi-Experimental Study
Roe, David; Hasson-Ohayon, Ilanit; Mashiach-Eizenberg, Michal; Derhy, Oren; Lysaker, Paul H.; Yanos, Philip T.
2014-01-01
Objective Accumulated evidence suggests that approximately one third of people with a serious mental illness (SMI) experience elevated self-stigma. Narrative enhancement and cognitive therapy (NECT) is a structured group-based intervention aimed to reduce self-stigma. The current study aims to examine the effectiveness of NECT. A quasi-experimental design. Design Baseline and follow-up data were collected and outcomes were compared between 63 persons with SMI who participated in NECT and 56 persons who received treatment as usual. Results The NECT treatment group showed significant (p < .05) reductions in self-stigma and increases in self-esteem, quality of life, and Hope-Agency scores between pre- and posttreatment assessments, compared with the control group. Conclusions The current results provide preliminary support for the use of NECT as an effective treatment to reduce self-stigma and its implications for treatment and practice are discussed. PMID:24114797
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ERIC Educational Resources Information Center
Walsh, Mary; Raczek, Anastasia; Sibley, Erin; Lee-St. John, Terrence; An, Chen; Akbayin, Bercem; Dearing, Eric; Foley, Claire
2015-01-01
While randomized experimental designs are the gold standard in education research concerned with causal inference, non-experimental designs are ubiquitous. For researchers who work with non-experimental data and are no less concerned for causal inference, the major problem is potential omitted variable bias. In this presentation, the authors…
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Application of Three Quasi-Experimental Designs.
ERIC Educational Resources Information Center
Cordray, David S.
Presented as part of a symposium on evaluation on juvenile diversion programs, this brief paper describes several specific research procedures which have been utilized to help decide which type of diversion approach is best for specific types of clients. Procedures discussed are the regression discontinuity design, the tie-breaker design, and the…
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Student and Teacher Outcomes of The Superkids Quasi-Experimental Study
ERIC Educational Resources Information Center
Borman, Geoffrey D.; Dowling, N. Maritza
2009-01-01
In this article, we report kindergarten student and teacher outcomes from a quasi-experimental evaluation of The Superkids, a systematic, phonics-based, comprehensive K-2 reading program. We recruited 23 kindergarten teachers to implement The Superkids program from a diverse, yet predominantly ethnic minority, group of classrooms from across the…
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Reflections on Critical Thinking: Lessons from a Quasi-Experimental Study
ERIC Educational Resources Information Center
Grussendorf, Jeannie; Rogol, Natalie C.
2018-01-01
In a pre/post quasi-experimental study assessing the impact of a specific curriculum on critical thinking, the authors employed a critical thinking curriculum in two sections of a U.S. foreign policy class. The authors found that the interactive and scaffolded critical thinking curriculum yielded statistically significant critical thinking…
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Robinson, Whitney R
2012-12-01
In countries undergoing nutrition transition and historically poor minority groups in wealthy countries, obesity tends to be more common in women than men. A potential contributor to this female excess of obesity is a mismatch between perinatal nutritional restriction and a later calorie-rich environment. Several epidemiologic and quasi-experimental studies support a gender-differential effect of early nutritional deprivation on adult obesity. The quasi-experimental studies are of particular interest because results of quasi-experimental studies are typically less vulnerable to confounding bias than observational studies. Four quasi-experimental studies-exploiting 20th century famines that occurred in Europe, Africa, and Asia-provide evidence that perinatal nutritional restriction followed by relative caloric abundance may increase adult obesity risk to a greater extent in women than men. If the findings are accurate and generalizable to contemporary food environments, they suggest that the female offspring of poor, or otherwise nutritionally restricted, women in rapidly developing and wealthy countries may be at particularly high risk of adult obesity. Research into gender-specific effects of early life nutritional deprivation and its interactions with later environmental exposures may provide insight into global gender differences in obesity prevalence.
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Comparison of a quasi-3D analysis and experimental performance for three compact radial turbines
NASA Technical Reports Server (NTRS)
Simonyi, P. S.; Boyle, R. J.
1991-01-01
An experimental aerodynamic evaluation of three compact radial turbine builds was performed. Two rotors which were 40-50 percent shorter in axial length than conventional state-of-the-art radial rotors were tested. A single nozzle design was used. One rotor was tested with the nozzle at two stagger angle settings. A second rotor was tested with the nozzle in only the closed down setting. Experimental results were compared to predicted results from a quasi-3D inviscid and boundary layer analysis, called MTSB (Meridl/Tsonic/Blayer). This analysis was used to predict turbine performance. It has previously been calibrated only for axial, not radial, turbomachinery. The predicted and measured efficiencies were compared at the design point for the three turbines. At the design points the analysis overpredicted the efficiency by less than 1.7 points. Comparisons were also made at off-design operating points. The results of these comparisons showed the importance of an accurate clearance model for efficiency predictions and also that there are deficiencies in the incidence loss model used.
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Comparison of a quasi-3D analysis and experimental performance for three compact radial turbines
NASA Technical Reports Server (NTRS)
Simonyi, P. S.; Boyle, R. J.
1991-01-01
An experimental aerodynamic evaluation of three compact radial turbine builds was performed. Two rotors which were 40 to 50 percent shorter in axial length than conventional state of the art radial rotors were tested. A single nozzle design was used. One rotor was tested with the nozzle at two stagger angle settings. A second rotor was tested with the nozzle in only the closed down setting. Experimental results were compared to predict results from a quasi-3D inviscid and boundary layer analysis, called Meridl/Tsonic/Blayer (MTSB). This analysis was used to predict turbine performance. It has previously been calibrated only for axial, not radial, turbomachinery. The predicted and measured efficiencies were compared at the design point for the three turbines. At the design points the analysis overpredicted the efficiency by less than 1.7 points. Comparisons were also made at off-design operating points. The results of these comparisons showed the importance of an accurate clearance model for efficiency predictions and also that there are deficiencies in the incidence loss model used.
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ERIC Educational Resources Information Center
Iman, Jaya Nur
2017-01-01
This research was conducted to find out whether or not using short stories significantly improve the speaking and writing achievements. A quasi-experimental study of non-equivalent pretest-posttest control group design or comparison group design was used in this research. The population of this research was the all first semester undergraduate…
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School Context and Educational Outcomes: Results from a Quasi-Experimental Study
Casciano, Rebecca; Massey, Douglas S.
2013-01-01
In this study we draw on data from a quasi-experimental study to test whether moving into a subsidized housing development in an affluent suburb yields educational benefits to the children of residents, compared to the educations they would have received had they not moved into the development. Results suggest that resident children experienced a significant improvement in school quality compared with a comparison group of students whose parents also had applied for residence. Parents who were residents of the development also displayed higher levels of school involvement compared with the comparison group of non-resident parents, and their children were exposed to significantly lower levels of school disorder and violence within school and spent more time reading outside of school. Living in the development did not influence GPA directly, but did indirectly increase GPA by increasing the time residents spent reading outside of school. PMID:25342878
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ERIC Educational Resources Information Center
Moore, Kristin Anderson
2008-01-01
Although experimental studies are described as the "gold standard" for assessing the effectiveness of a program in changing outcomes, in some cases, quasi-experimental studies may be more feasible or appropriate. Many types of quasi-experimental studies are possible. For example, an implementation study can provide valuable information on whether,…
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Development of a Woven-Grid Quasi-Bipolar Battery
NASA Technical Reports Server (NTRS)
Tokumaru, P.; Rippel, W.; Zambrano, T.
1998-01-01
This report describes an analytical and experimental investigation of AeroVironment's Quasi-Bipolar battery concept. The modelling/battery design part of the study demonstrates that there is a trade-off between thermal and specified electrical performance. Even so, quasi-bipolar batteries can be designed, with ten times better thermal uniformity, that meet or exceed current state-of-the-art hybrid-electric vehicle battery pack performance, even using the same active materials. The thermal uniformity, power, and energy for these quasi-bipolar battery packs is projected to be very good. The experimental part of the investigation demonstrates the concept of the quasi-bipolar plate applied to a lead foil current collector wrapping around two sides of an inexpensive plastic film core. Approximately 50 quasi-biplate samples were fabricated using a hot laminating press. Hot lamination with "texture" between the plastic and lead shows some promise as a low cost method for fabricating the plates. Five of these plates were assembled into two cells plus one two-cell battery. Data from these test cells were compared with existing data for similar true bipolar batteries. The positive side of the plates exhibited corrosion where not protected by the active material.
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Experimental Design and Some Threats to Experimental Validity: A Primer
ERIC Educational Resources Information Center
Skidmore, Susan
2008-01-01
Experimental designs are distinguished as the best method to respond to questions involving causality. The purpose of the present paper is to explicate the logic of experimental design and why it is so vital to questions that demand causal conclusions. In addition, types of internal and external validity threats are discussed. To emphasize the…
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NASA Astrophysics Data System (ADS)
Kazmi, K. R.; Khan, F. A.
2008-01-01
In this paper, using proximal-point mapping technique of P-[eta]-accretive mapping and the property of the fixed-point set of set-valued contractive mappings, we study the behavior and sensitivity analysis of the solution set of a parametric generalized implicit quasi-variational-like inclusion involving P-[eta]-accretive mapping in real uniformly smooth Banach space. Further, under suitable conditions, we discuss the Lipschitz continuity of the solution set with respect to the parameter. The technique and results presented in this paper can be viewed as extension of the techniques and corresponding results given in [R.P. Agarwal, Y.-J. Cho, N.-J. Huang, Sensitivity analysis for strongly nonlinear quasi-variational inclusions, Appl. MathE Lett. 13 (2002) 19-24; S. Dafermos, Sensitivity analysis in variational inequalities, Math. Oper. Res. 13 (1988) 421-434; X.-P. Ding, Sensitivity analysis for generalized nonlinear implicit quasi-variational inclusions, Appl. Math. Lett. 17 (2) (2004) 225-235; X.-P. Ding, Parametric completely generalized mixed implicit quasi-variational inclusions involving h-maximal monotone mappings, J. Comput. Appl. Math. 182 (2) (2005) 252-269; X.-P. Ding, C.L. Luo, On parametric generalized quasi-variational inequalities, J. Optim. Theory Appl. 100 (1999) 195-205; Z. Liu, L. Debnath, S.M. Kang, J.S. Ume, Sensitivity analysis for parametric completely generalized nonlinear implicit quasi-variational inclusions, J. Math. Anal. Appl. 277 (1) (2003) 142-154; R.N. Mukherjee, H.L. Verma, Sensitivity analysis of generalized variational inequalities, J. Math. Anal. Appl. 167 (1992) 299-304; M.A. Noor, Sensitivity analysis framework for general quasi-variational inclusions, Comput. Math. Appl. 44 (2002) 1175-1181; M.A. Noor, Sensitivity analysis for quasivariational inclusions, J. Math. Anal. Appl. 236 (1999) 290-299; J.Y. Park, J.U. Jeong, Parametric generalized mixed variational inequalities, Appl. Math. Lett. 17 (2004) 43-48].
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Rogers, Catherine; Anderson, Sarah E; Dollahite, Jamie S; Hill, Tisa F; Holloman, Chris; Miller, Carla K; Pratt, Keeley J; Gunther, Carolyn
2017-01-09
Given the ongoing childhood obesity public health crisis and potential protective effect of family meals, there is need for additional family meals research, specifically experimental studies with expanded health outcomes that focus on the at-risk populations in highest need of intervention. Future research, specifically intervention work, would also benefit from an expansion of the target age range to include younger children, who are laying the foundation of their eating patterns and capable of participating in family meal preparations. The purpose of this paper is to address this research gap by presenting the objectives and research methods of a 10-week multi-component family meals intervention study aimed at eliciting positive changes in child diet and weight status. This will be a group quasi-experimental trial with staggered cohort design. Data will be collected via direct measure and questionnaires at baseline, intervention completion (or waiting period for controls), and 10-weeks post-intervention. Setting will be faith-based community center. Participants will be 60 underserved families with at least 1, 4-10 year old child will be recruited and enrolled in the intervention (n = 30) or waitlist control group (n = 30). The intervention (Simple Suppers) is a 10-week family meals program designed for underserved families from racial/ethnic diverse backgrounds. The 10, 90-min program lessons will be delivered weekly over the dinner hour. Session components include: a) interactive group discussion of strategies to overcome family meal barriers, plus weekly goal setting for caregivers; b) engagement in age-appropriate food preparation activities for children; and c) group family meal for caregivers and children. Main outcome measures are change in: child diet quality; child standardized body mass index; and frequency of family meals. Regression models will be used to compare response variables results of intervention to control group, controlling for
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Left-turn phase: permissive, protected, or both? A quasi-experimental design in New York City.
Chen, Li; Chen, Cynthia; Ewing, Reid
2015-03-01
The practice of left-turn phasing selection (permissive, protected-only, or both) varies from one locality to another. The literature evidence on this issue is equally mixed and insufficient. In this study, we evaluate the safety impacts of changing left-turn signal phasing from permissive to protected/permissive or protected-only at 68 intersections in New York City using a rigorous quasi-experimental design accompanied with regression modeling. Changes in police reported crashes including total crashes, multiple-vehicle crashes, left-turn crashes, pedestrian crashes and bicyclist crashes were compared between before period and after period for the treatment group and comparison group by means of negative binomial regression using a Generalized Estimating Equations (GEE) technique. Confounding factors such as the built environment characteristics that were not controlled in comparison group selection are accounted for by this approach. The results show that the change of permissive left-turn signal phasing to protected/permissive or protected-only signal phasing does not result in a significant reduction in intersection crashes. Though the protected-only signal phasing does reduce the left-turn crashes and pedestrian crashes, this reduction was offset by a possible increase in over-taking crashes. These results suggest that left-turn phasing should not be treated as a universal solution that is always better than the permissive control for left-turn vehicles. The selection and implementation of left-turn signal phasing needs to be done carefully, considering potential trade-offs between safety and delay, and many other factors such as geometry, traffic flows and operations. Copyright © 2014 Elsevier Ltd. All rights reserved.
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Evaluating E-Training for Public Library Staff: A Quasi-Experimental Investigation
ERIC Educational Resources Information Center
Dalston, Teresa
2009-01-01
A comparative evaluation framework of instructional interventions for implementation of online training for public library staff would enable a better understanding of how to improve the effectiveness, efficiency and efficacy of training in certain training environments. This dissertation describes a quasi-experimental study of a two-week,…
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The effectiveness of ethics education: a quasi-experimental field study.
May, Douglas R; Luth, Matthew T
2013-06-01
Ethical conduct is the hallmark of excellence in engineering and scientific research, design, and practice. While undergraduate and graduate programs in these areas routinely emphasize ethical conduct, few receive formal ethics training as part of their curricula. The first purpose of this research study was to assess the relative effectiveness of ethics education in enhancing individuals' general knowledge of the responsible conduct of research practices and their level of moral reasoning. Secondly, we examined the effects of ethics education on the positive psychological outcomes of perspective-taking, moral efficacy, moral courage, and moral meaningfulness. To examine our research hypotheses, we utilized a pretest-posttest quasi-experimental design consisting of three ethics education groups (control, embedded modules, and stand-alone courses). Findings revealed that both embedded and stand alone courses were effective in enhancing participants' perspective-taking, moral efficacy, and moral courage. Moral meaningfulness was marginally enhanced for the embedded module condition. Moral judgment and knowledge of responsible conduct of research practices were not influenced by either ethics education condition. Contrary to expectations, stand alone courses were not superior to embedded modules in influencing the positive psychological outcomes investigated. Implications of these findings for future research and practice are discussed.
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Father's Role in Breastfeeding Promotion: Lessons from a Quasi-Experimental Trial in China.
Su, Min; Ouyang, Yan-Qiong
2016-04-01
The aims of this study were to evaluate the effectiveness of an educational intervention involving fathers on breastfeeding initiation and exclusive breastfeeding rate, and to explore mothers' perceptions of their partners' support of breastfeeding. This study was a quasi-experimental pretest-posttest design with two groups. A convenience sample consisting of 72 expectant mothers was recruited. Thirty-six women with their partners were assigned to the intervention group, and 36 women alone were in the control group. Both groups were offered similar education contents, and the intervention group was given additional information on how fathers could support their partners, both emotionally and physically, during the breastfeeding process. Student's t test, chi-square test, and Mann-Whitney U test were used to detect group differences. The prevalence rates of exclusive breastfeeding at 4 months and 6 months of the intervention group were significantly higher than there were in the control group (51.4% and 26.4%, p = 0.034; 40.0% and 17.6%, p = 0.041). Women in the intervention group were less likely to use infant formula at 1 and 6 months postpartum (5.6% and 23.5%, p = 0.032; 20.0% and 44.1%, p = 0.032). Related to the process of breastfeeding, partners in the intervention group supported their partners by taking care of the infant, doing housework, and providing emotional support. Involving the fathers in breastfeeding education could improve the exclusive breastfeeding rate and prolong the duration of exclusive breastfeeding. The mothers appreciated support from the fathers.
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Class, Quetzal A.; D’Onofrio, Brian M.; Singh, Amber L.; Ganiban, Jody M.; Spotts, E. L.; Lichtenstein, Paul; Reiss, David; Neiderhiser, Jenae M.
2013-01-01
A genetically-informed, quasi-experimental design was used to examine the genetic and environmental processes underlying associations between current parental depressive symptoms and offspring perceived self-competence. Participants, drawn from a population-based Swedish sample, were 852 twin pairs and their male (52%) and female offspring aged 15.7 ± 2.4 years. Parental depressive symptoms were measured using the Center for Epidemiological Studies Depression scale. Offspring perceived self-competence was measured using a modified Harter Perceived Competence Scale. Cousin comparisons and Children of Twins (CoT) designs suggested that associations between maternal depressive symptoms and offspring perceived self-competence were due to shared genetic/environmental liability. The mechanism responsible for father-offspring associations, however, was independent of genetic factors and of extended-family environmental factors, supporting a causal inference. Thus, mothers and fathers may impact offspring perceived self-competence via different mechanisms and unmeasured genetic and environmental selection factors must be considered when studying the intergenerational transmission of cognitive vulnerabilities for depression. PMID:22692226
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Class, Quetzal A; D'Onofrio, Brian M; Singh, Amber L; Ganiban, Jody M; Spotts, E L; Lichtenstein, Paul; Reiss, David; Neiderhiser, Jenae M
2012-09-01
A genetically-informed, quasi-experimental design was used to examine the genetic and environmental processes underlying associations between current parental depressive symptoms and offspring perceived self-competence. Participants, drawn from a population-based Swedish sample, were 852 twin pairs and their male (52 %) and female offspring aged 15.7 ± 2.4 years. Parental depressive symptoms were measured using the Center for Epidemiological Studies Depression scale. Offspring perceived self-competence was measured using a modified Harter Perceived Competence Scale. Cousin comparisons and Children of Twins designs suggested that associations between maternal depressive symptoms and offspring perceived self-competence were due to shared genetic/environmental liability. The mechanism responsible for father-offspring associations, however, was independent of genetic factors and of extended family environmental factors, supporting a causal inference. Thus, mothers and fathers may impact offspring perceived self-competence via different mechanisms and unmeasured genetic and environmental selection factors must be considered when studying the intergenerational transmission of cognitive vulnerabilities for depression.
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Quasi-Experimental Approaches to Evaluating the Impact of Air Pollution on Children’s Health
Heep, Samantha; Neidell, Matthew
2016-01-01
Many studies have shown a correlation between air pollution and poor children’s health. This paper focuses on recent studies that employ quasi-experimental designs in an effort to minimize the effect of confounding factors. These studies are complementary to studies using other designs and confirm that reducing air pollution reduces infant mortality, low birth weight, prematurity, congenital anomalies, asthma hospitalizations, and school absences. These results suggest that lowering the thresholds for acceptable air pollution levels may be prudent, as research has consistently found that some pollutants have negative impacts even at levels below current regulatory thresholds. Policy makers should also consider providing more information to pregnant women and families about when and where the risk of pollution exposure is highest so that they can employ avoidance behavior. PMID:22147868
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ERIC Educational Resources Information Center
Wilhelm, William J.; Czyzewski, Alan B.
2006-01-01
This study was designed to identify classroom interventions that can be used by core business course instructors (as opposed to trained business ethicists) to positively affect levels of moral reasoning in undergraduate business students. The quasi-experimental study conducted at a Midwestern university, focused on determining if the utilization…
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Santaeugènia, Sebastià J; García-Lázaro, Manuela; Alventosa, Ana María; Gutiérrez-Benito, Alícia; Monterde, Albert; Cunill, Joan
To evaluate the clinical effectiveness of an intermediate care model based on a system of care focused on integrated care pathways compared to the traditional model of geriatric care (usual care) in Catalonia. The design is a quasi-experimental pre-post non-randomised study with non-synchronous control group. The intervention consists of the development and implementation of integrated care pathways and the creation of specialised interdisciplinary teams in each of the processes. The two groups will be compared for demographic, clinical variables on admission and discharge, geriatric syndromes, and use of resources. This quasi-experimental study, aims to assess the clinical impact of the transformation of a traditional model of geriatric care to an intermediate care model in an integrated healthcare organisation. It is believed that the results of this study may be useful for future randomised controlled studies. Copyright © 2016 SEGG. Publicado por Elsevier España, S.L.U. All rights reserved.
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Abel, Eileen Mazur; Chung-Canine, Unju; Broussard, Karen
2013-01-01
Despite the fact that children are negatively impacted by family separation and divorce (Amato, 2001 ; Dreman & Shemi, 2004 ; Kelly, 2000 ) there is a paucity of information regarding evidence-based social work practice with children coping with family disruption. In order to address this gap, the authors describe the process and outcomes of a quasi-experimental evaluation (N = 79) designed to reduce the behavioral, emotional, and academic problems that children often face when experiencing divorce or parental separation. Results of data analysis (paired t-tests, independent t-tests, and analysis of variance) suggest (p < .05) that the intervention is effective in helping children cope with family disruption.
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Evidence for several dipolar quasi-invariants in liquid crystals
NASA Astrophysics Data System (ADS)
Bonin, C. J.; González, C. E.; Segnorile, H. H.; Zamar, R. C.
2013-10-01
The quasi-equilibrium states of an observed quantum system involve as many constants of motion as the dimension of the operator basis which spans the blocks of all the degenerate eigenvalues of the Hamiltonian that drives the system dynamics, however, the possibility of observing such quasi-invariants in solid-like spin systems in Nuclear Magnetic Resonance (NMR) is not a strictly exact prediction. The aim of this work is to provide experimental evidence of several quasi-invariants, in the proton NMR of small spin clusters, like nematic liquid crystal molecules, in which the use of thermodynamic arguments is not justified. We explore the spin states prepared with the Jeener-Broekaert pulse sequence by analyzing the time-domain signals yielded by this sequence as a function of the preparation times, in a variety of dipolar networks, solids, and liquid crystals. We observe that the signals can be explained with two dipolar quasi-invariants only within a range of short preparation times, however at longer times liquid crystal signals show an echo-like behaviour whose description requires assuming more quasi-invariants. We study the multiple quantum coherence content of such signals on a basis orthogonal to the z-basis and see that such states involve a significant number of correlated spins. Therefore, we show that the NMR signals within the whole preparation time-scale can only be reconstructed by assuming the occurrence of multiple quasi-invariants which we experimentally isolate.
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Cadiz, David M; O'Neill, Chris; Butell, Sue S; Epeneter, Beverly J; Basin, Basilia
2012-07-01
This article reports on a study that evaluated the effectiveness of an educational intervention, Addressing Nurse Impairment, for addressing nursing students' knowledge acquisition, changes in self-efficacy to intervene, and changes in substance abuse stigma. A gap exists in nursing students' education regarding the risks of addiction within the profession and how to handle a colleague suspected of having a substance use disorder. The seminar was adapted from an existing evidence-based prevention program called Team Awareness, as well as information from focus groups and a pilot test. A quasi-experimental pretest-posttest design was used to evaluate the effect of the seminar. When the control and experimental groups were compared, the results indicated that the seminar significantly affected knowledge and self-efficacy to intervene but did not significantly affect stigma. This research contributes to the body of evidence related to educational interventions for nursing students regarding substance abuse in the nursing profession. Copyright 2012, SLACK Incorporated.
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Riddle, Daniel L.; Keefe, Francis J.; Nay, William T.; McKee, Daphne; Attarian, David E.; Jensen, Mark P.
2011-01-01
Objectives To (1) describe a behavioral intervention designed for patients with elevated pain catastrophizing who are scheduled for knee arthroplasty, and (2) use a quasi-experimental design to evaluate the potential efficacy of the intervention on pain severity, catastrophizing cognitions, and disability. Design Quasi-experimental non-equivalent control group design with a 2 month follow-up. Setting Two university-based Orthopedic Surgery departments. Participants Adults scheduled for knee replacement surgery who reported elevated levels of pain catastrophizing. Patients were recruited from two clinics and were assessed prior to surgery and 2 months following surgery. Intervention A group of 18 patients received a psychologist directed pain coping skills training intervention comprising 8 sessions and the other group, a historical cohort of 45 patients, received usual care. Main Outcome Measures WOMAC Pain and Disability scores as well as scores on the Pain Catastrophizing Scale. Results Two months following surgery, the patients who received pain coping skills training reported significantly greater reductions in pain severity and catastrophizing, and greater improvements in function as compared to the usual care cohort. Conclusion Pain catastrophizing is known to increase risk of poor outcome following knee arthroplasty. The findings provide preliminary evidence that the treatment may be highly efficacious for reducing pain, catastrophizing, and disability, in patients reporting elevated catastrophizing prior to knee arthroplasty. A randomized clinical trial is warranted to confirm these effects. PMID:21530943
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Henderson, Amanda; Burmeister, Liz; Schoonbeek, Sue; Ossenberg, Christine; Gneilding, Julieanne
2014-11-01
This study evaluated the impact of different levels of engaging middle management in ward based strategies implemented by a project educator. The challenge for learning in practice is to develop effective teams where experienced staff engage and foster learning with students and other novice staff. A quasi-experimental pre- and post- intervention four group design was conducted from November 2009 to May 2010 across four general surgical and four general medical inpatient matched units in two settings in South East Queensland, Australia. Staff survey data was used to compare control and intervention groups (one actively engaging nurse managers) before and after 'practice learning' interventions. The survey comprised demographic data and data from two validated scales (support instrument for nurses facilitating learning and clinical learning organisational culture). Number of surveys returned pre- and post-intervention was 336 from 713 (47%). There were significant differences across many subscales pertaining to staff perception of support in the intervention groups, with only one change in the control group. The number of significant different subscales in the learning culture was also greater when middle management supported the intervention. Middle management should work closely with facilitators to assist embedding practice interventions. © 2013 John Wiley & Sons Ltd.
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Chen, Chia-Ying; Kao, Chia-Chan; Hsu, Hsiu-Yueh; Wang, Ruey-Hsia; Hsu, Shu-Hua
2015-10-01
The purpose of this quasi-experimental study was to assess the efficacy of a family-based (FB) weight-loss and behavior-modification intervention among overweight/obese children (age 9-11 years) and their parents in Taiwan. The intervention group (52 child-parent dyads) participated in an FB program for 7 weeks. The control group (55 child-parent dyads) received an educational pamphlet about obesity prevention. The children's body mass index (BMI) z-scores were the primary outcome variable. The parents' BMI, high-calorie (HC) food-intake behaviors, screen-related behaviors, and restrictions on children's consumption of HC foods and screen-related behaviors and the availability of HC foods at home were the secondary outcome variables. Outcome variables were measured at baseline (T0), at the end of the intervention (T1), and 4 weeks after the end of the intervention (T2). A linear mixed model was used to assess the efficacy of the FB program. Results indicated that the children's BMI z-scores decreased significantly more from T0 to T2 in the experimental group than in the control group. The decreases in parents' HC food-intake behaviors and availability of HC foods at home and the increase in parental restrictions on children's consumption of HC foods were significantly greater in the experimental than in the control group from T0 to T1 and T0 to T2. The FB program was effective in modifying parental behaviors and the weight of overweight/obese children in a Taiwanese population. © The Author(s) 2015.
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Interprofessional teamwork among students in simulated codes: a quasi-experimental study.
Garbee, Deborah D; Paige, John; Barrier, Kendra; Kozmenko, Valeriy; Kozmenko, Lyubov; Zamjahn, John; Bonanno, Laura; Cefalu, Jean
2013-01-01
The purpose of this study was to evaluate the efficacy of using crisis resource management (CRM) principles and high-fidelity human patient simulation (HFHPS) for interprofessional (IP) team training of students from undergraduate nursing, nurse anesthesia, medical, and respiratory therapy. IP education using simulation-based training has the potential to transform education by improving teamwork and communication and breaking down silos in education. This one-year study used a quasi-experimental design to evaluate students' acquisition and retention of teamwork and communication skills. A convenience sample consisted of 52 students in the fall semester, with 40 students returning in the spring. Mean scores increased after training, and skills were retained fairly well. Any loss was regained with repeat training in the spring. The results suggest that using CRM and HFHPS is an effective pedagogy for teaching communication and teamwork skills to IP student teams.
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Efficacy of a footbath for post-partum fatigue in South Korea: A quasi-experimental study.
Choi, Eunsun; Song, Eunju
2017-04-01
The purpose of this study was to identify the effects of a footbath on post-partum fatigue. This study used a quasi-experimental design by using an unequivalent control group, pre-post-test design. The participants were divided into experimental and control groups. Fifty post-partum women who were admitted to an obstetrics and gynecology ward of a general hospital were the experimental group and 50 post-partum women who were admitted to an obstetrics and gynecology ward of a women's hospital were the control group. Two hospitals were providing similar postnatal care to their patients and they were located in the same city. The experimental group received a footbath along with postnatal care at the hospital, while the control group received only postnatal care from the hospital. Each group completed the Fatigue Continuum Form at a specified time. The general characteristics and pretest dependent variables were homogenous between the two groups. The hypothesis was supported post-test as the Fatigue Continuum Form scores differed significantly between the experimental and the control groups. This study showed that a footbath helps to decrease fatigue among post-partum women. In addition, it is a good preventative strategy for post-partum women who should initiate it in the early post-partum period. © 2016 Japan Academy of Nursing Science.
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Borglin, Gunilla; Gustafsson, Markus; Krona, Hans
2011-09-23
Pain is one of the most frequent problems among patients diagnosed with cancer. Despite the availability of effective pharmacological treatments, this group of patients often receives less than optimal treatment. Research into nurses' pain management highlights certain factors, such as lack of knowledge and attitudes and inadequate procedures for systematic pain assessment, as common barriers to effective pain management. However, educational interventions targeting nurses' pain management have shown promise. As cancer-related pain is also known to have a negative effect on vital aspects of the patient's life, as well as being commonly associated with problems such as sleep, fatigue, depression and anxiety, further development of knowledge within this area is warranted. A quasi-experimental study design will be used to investigate whether the implementation of guidelines for systematic daily pain assessments following a theory-based educational intervention will result in an improvement in knowledge and attitude among nurses. A further aim is to investigate whether the intervention that targets nurses' behaviour will improve hospital patients' perception of pain. Data regarding nurses' knowledge and attitudes to pain (primary outcome), patient perception regarding pain (secondary outcome), together with socio-demographic variables, will be collected at baseline and at four weeks and 12 weeks following the intervention. Nursing care is nowadays acknowledged as an increasingly complicated activity and "nursing complexity is such that it can be seen as the quintessential complex intervention." To be able to change and improve clinical practice thus requires multiple points of attack appropriate to meet complex challenges. Consequently, we expect the theory-based intervention used in our quasi-experimental study to improve care as well as quality of life for this group of patients and we also envisage that evidence-based guidelines targeting this patient group's pain
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A millimeter wave quasi-optical mixer and multiplier
NASA Technical Reports Server (NTRS)
1977-01-01
The results of an experimental study of a biconical quasi-optical Schottky barrier diode mount design which could be used for mixing and multiplying in the frequency range 200-1000 Ghz are reported. The biconical mount is described and characteristics measured at 185 Ghz are presented. The use of the mount for quasi-optical frequency doubling from 56 to 112 Ghz is described and efficiency estimates given.
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Hsieh, Ching-Hsing; Chen, Chien-Lan; Chung, Feng-Fang; Lin, Su-Ying
2017-05-01
Postpartum fatigue is one of the most common complaints among women following childbirth. As a postpartum ritual practice, Taiwanese women refrain from taking showers while "doing the month." However, warm showers are the systemic application of moist heat, and they maintain physical hygiene, stimulate blood circulation, mitigate discomfort, and provide relaxation. As Taiwanese society becomes increasingly receptive to scientific and contemporary health care practice, more and more women choose to take warm showers after childbirth. The purpose of this study was to evaluate the efficacy of warm showers on postpartum fatigue among vaginal-birth women in Taiwan. This was a two-group quasi-experimental design. Women took showers in warm water with temperatures ranging between 40 °C and 43 °C for approximately 20 minutes. Postpartum women's fatigue is measured using the 10-item Postpartum Fatigue Scale (PFS). The intervention effect was analyzed using a generalized estimating equation (GEE) model. The study population consisted of 358 vaginal-birth postpartum Taiwanese women aged 20-43 years. Postpartum women who took warm showers showed improvements from their pretest to posttest mean scores of postpartum fatigue compared to postpartum women who did not take warm showers. Warm showers helped to reduce postpartum fatigue among vaginal-birth women during the study period. Nurses have the unique opportunity to provide the intervention to Taiwanese women who have vaginal birth to help them relieve postpartum fatigue with warm showers while "doing the month" without the taboo of no-showering customary practices in the early postpartum period.
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NASA Astrophysics Data System (ADS)
Gurovich, V.; Virozub, A.; Rososhek, A.; Bland, S.; Spielman, R. B.; Krasik, Ya. E.
2018-05-01
A major experimental research area in material equation-of-state today involves the use of off-Hugoniot measurements rather than shock experiments that give only Hugoniot data. There is a wide range of applications using quasi-isentropic compression of matter including the direct measurement of the complete isentrope of materials in a single experiment and minimizing the heating of flyer plates for high-velocity shock measurements. We propose a novel approach to generating quasi-isentropic compression of matter. Using analytical modeling and hydrodynamic simulations, we show that a working fluid composed of compressed water, generated by an underwater electrical explosion of a planar wire array, might be used to efficiently drive the quasi-isentropic compression of a copper target to pressures ˜2 × 1011 Pa without any complex target designs.
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Leysen, Bert; Van den Eynden, Bart; Gielen, Birgit; Bastiaens, Hilde; Wens, Johan
2015-09-28
Starting with early identification of palliative care patients by general practitioners (GPs), the Care Pathway for Primary Palliative Care (CPPPC) is believed to help primary health care workers to deliver patient- and family-centered care in the last year of life. The care pathway has been pilot-tested, and will now be implemented in 5 Belgian regions: 2 Dutch-speaking regions, 2 French-speaking regions and the bilingual capital region of Brussels. The overall aim of the CPPPC is to provide better quality of primary palliative care, and in the end to reduce the hospital death rate. The aim of this article is to describe the quantitative design and innovative data collection strategy used in the evaluation of this complex intervention. A quasi-experimental stepped wedge cluster design is set up with the 5 regions being 5 non-randomized clusters. The primary outcome is reduced hospital death rate per GPs' patient population. Secondary outcomes are increased death at home and health care consumption patterns suggesting high quality palliative care. Per research cluster, GPs will be recruited via convenience sampling. These GPs -volunteering to be involved will recruit people with reduced life expectancy and their informal care givers. Health care consumption data in the last year of life, available for all deceased people having lived in the research clusters in the study period, will be used for comparison between patient populations of participating GPs and patient populations of non-participating GPs. Description of baseline characteristics of participating GPs and patients and monitoring of the level of involvement by GPs, patients and informal care givers will happen through regular, privacy-secured web-surveys. Web-survey data and health consumption data are linked in a secure way, respecting Belgian privacy laws. To evaluate this complex intervention, a quasi-experimental stepped wedge cluster design has been set up. Context characteristics and involvement
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Navarro-Patón, R; Freire-Tellado, M; Basanta-Camiño, S; Barcala-Furelos, R; Arufe-Giraldez, V; Rodriguez-Fernández, J E
2018-05-01
To evaluate the learning of basic life support (BLS) measures on the part of laypersons after 3different teaching programs. A quasi-experimental before-after study involving a non-probabilistic sample without a control group was carried out. Primary school teacher students from the University of Santiago (Spain). A total of 124 students (68.8% women and 31.2% men) aged 20-39 years (M=22.23; SD=3.79), with no previous knowledge of BLS, were studied. Three teaching programs were used: a traditional course, an audio-visual approach and feedback devices. Chest compressions as sole cardiopulmonary resuscitation skill evaluation: average compression depth, compression rate, chest recoil percentage and percentage of correct compressions. Automated external defibrillator: time needed to apply a shock before and after the course. There were significant differences in the results obtained after 2minutes of chest compressions, depending on the training program received, with feedback devices having a clear advantage referred to average compression depth (p<0.001), compression rate (p<0.001), chest recoil percentage (p<0.001) and percentage of correct compressions (p<0.001). Regarding automated external defibrillator, statistically significant differences were found in T after (p=0.025). The teaching course using feedback devices obtained the best results in terms of the quality of chest compressions, followed by the traditional course and audio-visual approach. These favorable results were present in both men and women. All 3teaching methods reached the goal of reducing defibrillation time. Copyright © 2017 Elsevier España, S.L.U. y SEMICYUC. All rights reserved.
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Spatial Visualization Ability and Impact of Drafting Models: A Quasi Experimental Study
ERIC Educational Resources Information Center
Katsioloudis, Petros J.; Jovanovic, Vukica
2014-01-01
A quasi experimental study was done to determine significant positive effects among three different types of visual models and to identify whether any individual type or combination contributed towards a positive increase of spatial visualization ability for students in engineering technology courses. In particular, the study compared the use of…
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Evaluating the Madrasa Preschool Programme in East Africa: A Quasi-Experimental Study
ERIC Educational Resources Information Center
Mwaura, Peter A. M.; Sylva, Kathy; Malmberg, Lars-Erik
2008-01-01
This study investigated the effect of preschool experience (two types of preschool: Madrasa and non-Madrasa) on the cognitive development of children in East Africa. In the three countries studied (Kenya, Uganda, and Tanzania/Zanzibar) preschool education is burgeoning and government standards are being set. This quasi experimental evaluation used…
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Robitaille, Yvonne; Fournier, Michel; Laforest, Sophie; Gauvin, Lise; Filiatrault, Johanne; Corriveau, Hélène
2012-08-01
To examine the effect of a fall prevention program offered under real-world conditions on balance maintenance several months after the program. To explore the program's impact on falls. A quasi-experimental study was conducted among community-dwelling seniors, with pre- and postintervention measures of balance performance and self-reported falls. Ten community-based organizations offered the intervention (98 participants) and 7 recruited participants to the study's control arm (102 participants). An earlier study examined balance immediately after the 12-week program. The present study focuses on the 12-month effect. Linear regression (balance) and negative binomial regression (falls) procedures were performed.falls. During the 12-month study period, experimental participants improved and maintained their balance as reflected by their scores on three performance tests. There was no evidence of an effect on falls.falls. Structured group exercise programs offered in community-based settings can maintain selected components of balance for several months after the program's end.
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Quasi-Experiments in Schools: The Case for Historical Cohort Control Groups
ERIC Educational Resources Information Center
Walser, Tamara M.
2014-01-01
There is increased emphasis on using experimental and quasi-experimental methods to evaluate educational programs; however, educational evaluators and school leaders are often faced with challenges when implementing such designs in educational settings. Use of a historical cohort control group design provides a viable option for conducting…
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Breastfeeding and externalising problems: a quasi-experimental design with a national cohort.
Girard, Lisa-Christine; Doyle, Orla; Tremblay, Richard E
2018-07-01
Evidence from correlational studies supporting the benefits of breastfeeding on children's externalising problems is mixed. Quasi-experimental approaches can help in better understanding possible 'effects'. We aimed to investigate the longitudinal impact of breastfeeding on externalising problems from childhood into adolescence. Participants included ~ 5000 full-term children, from the Growing Up in Ireland Child Cohort. Externalising problems (conduct problems and hyperactivity) were assessed using both the parent and teacher versions of the Strengths and Difficulties Questionnaire when children were age 9 and 13. Maternal reports were used to collect retrospective information on breastfeeding. Propensity score matching, and adjusting for multiple testing were used to compare the average treatment effects for children who were breastfed. Post matching results revealed statistically significant reductions in hyperactivity at age nine, using both maternal and teacher reports (difference score - 0.48, 95% CI - 0.85, - 0.11; and - 0.51, 95% CI - 0.90, - 0.12, respectively), for children who were breastfed between 6 and 12 months, but not thereafter. These effects were not maintained at age 13. Moreover, no effects of breastfeeding on conduct problems were found at any age, regardless of duration, using either maternal or teacher report. While some benefits of breastfeeding were found, compatible with a temporary modest reduction in hyperactivity, related to being breastfed for 26-50 weeks, these results must be viewed in the context of reliance of propensity score matching on observable characteristics. Additionally, our results are suggestive of a potential non-linear dose-response of breastfeeding on hyperactivity.
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Shorey, Shefaly; Kowitlawakul, Yanika; Devi, M Kamala; Chen, Hui-Chen; Soong, Swee Kit Alan; Ang, Emily
2018-02-01
Effective communication is important for nurse and patient outcomes. Nursing students often feel unprepared to communicate effectively with patients and other healthcare workers within the clinical environment. Blended learning pedagogy-based communication skills training can provide an alternative to traditional methods of teaching to enhance students' satisfaction and self-efficacy levels in communicating with others. To examine the effectiveness of blended learning pedagogy in a redesigned communication module among nursing undergraduates in enhancing their satisfaction levels and attitudes towards learning communication module as well as self-efficacy in communication. A single group pre-test and post-test quasi-experimental design was adopted. Data were collected from August 2016 to November 2016 from 124 nursing undergraduates from a leading nursing school. Blended learning pedagogy was adopted to redesign a communication module that offered a wide array of learning opportunities via face-to-face classroom and online sessions. Validated and reliable instruments were used to measure satisfaction levels with blended learning pedagogy, attitudes towards learning communication, and communication self-efficacy. Descriptive and inferential statistics were used to analyze the data. Participants had enhanced satisfaction levels with blended learning pedagogy, better attitudes in learning communication skills, and improved communication self-efficacies at posttest (week 13 of the semester) when compared with their pre-test scores (week one of the semester). Participants scored higher in the Blended Learning Satisfaction Scale, the Communication Skills Attitude Scale, and the communication skills subscale of the Nursing Students Self-Efficacy Scale. Blended learning pedagogy can be effectively used in facilitating communication modules and enhancing student outcomes among nursing undergraduates. The long-term effectiveness of using blended learning pedagogy in
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Gisladottir, Margret; Treasure, Janet; Svavarsdottir, Erla Kolbrun
2017-03-01
The aim of this study was to evaluate the effectiveness of therapeutic conversation intervention in group and caregiver sessions on the supporting role of caregivers. Caregivers of people with eating disorders are known to suffer major difficulties and are in great need of support. Unhelpful parental support strategies can delay the recovery of an individual with an eating disorder. Skill training interventions can equip parents with skills, guidance and techniques by helping them to be a support person and making them one of the most important links in the treatment process. The therapeutic conversation intervention consisted of five group and caregiver sessions and three booster sessions. The Calgary Family Assessment and Calgary Family Intervention Models, the Illness Beliefs Model and the New Maudsley Method were used as theoretical frameworks. The content of the intervention consisted of work on difficult behaviours, feelings and helpful strategies. The participants (n = 58) included primary and secondary caregivers of 12- to 24-year-old patients with eating disorders. Eight caregivers dropped out of treatment. This study had a quasi-experimental design with one pre- and two post-test measures. Between 90-96% of caregivers rated the therapeutic conversation intervention as supportive. Furthermore, the study revealed significant differences in caregiver emotional and cognitive support, illness beliefs, disruptive behaviour and quality of life, negative aspects of care giving demands and caregiver and patient behavioural difficulties after the intervention and/or at follow-up. Therapeutic conversation intervention with caregivers in group and private sessions proved to be beneficial. This outcome provides information for healthcare professionals on how they can help primary caregivers in their supporting role, which can, in turn, improve services in healthcare centres and psychiatric hospitals. © 2016 John Wiley & Sons Ltd.
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Shardell, Michelle; Harris, Anthony D; El-Kamary, Samer S; Furuno, Jon P; Miller, Ram R; Perencevich, Eli N
2007-10-01
Quasi-experimental study designs are frequently used to assess interventions that aim to limit the emergence of antimicrobial-resistant pathogens. However, previous studies using these designs have often used suboptimal statistical methods, which may result in researchers making spurious conclusions. Methods used to analyze quasi-experimental data include 2-group tests, regression analysis, and time-series analysis, and they all have specific assumptions, data requirements, strengths, and limitations. An example of a hospital-based intervention to reduce methicillin-resistant Staphylococcus aureus infection rates and reduce overall length of stay is used to explore these methods.
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Stijnen, Mandy M N; Duimel-Peeters, Inge G P; Jansen, Maria W J; Vrijhoef, Hubertus J M
2013-01-18
Due to the ageing of the population, the number of frail older people who suffer from multiple, complex health complaints increases and this ultimately threatens their ability to function independently. Many interventions for frail older people attempt to prevent or delay functional decline, but they show contradicting results. Recent studies emphasise the importance of embedding these interventions into existing primary care systems and tailoring care to older people's needs and wishes. This article presents the design of an evaluation study, aiming to investigate the effects and feasibility of the early detection of health problems among community-dwelling older people and their subsequent referral to appropriate care and/or well-being facilities by general practices. A longitudinal, quasi-experimental study is designed comparing 13 intervention practices with 11 control practices. General practices select eligible community-dwelling older people (≥ 75 years). Practice nurses from intervention practices (1) visit older people at home for a comprehensive assessment of their health and well-being; (2) discuss results with the GP; (3) formulate - if required - a care and treatment plan together with the patient; (4) refer patient to care and/or well-being facilities; and (5) monitor and coordinate care and follow-up. Control practices provide usual care and match the intervention practices on the presence of different primary care professionals within the practice. Primary outcome measures are health-related quality of life and disability. Additionally, attitude towards ageing, care satisfaction, health care utilisation, nursing home admission and mortality are measured. Some outcomes are assessed by means of a postal questionnaire (at baseline and after 6, 12, and 18 months follow-up), others through continuous registration over the 18-month period. A profound process evaluation will provide insight into barriers and facilitators for implementing the intervention
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Pimperl, Alexander; Schulte, Timo; Mühlbacher, Axel; Rosenmöller, Magdalena; Busse, Reinhard; Groene, Oliver; Rodriguez, Hector P; Hildebrandt, Helmut
2017-06-01
A central goal of accountable care organizations (ACOs) is to improve the health of their accountable population. No evidence currently links ACO development to improved population health. A major challenge to establishing the evidence base for the impact of ACOs on population health is the absence of a theoretically grounded, robust, operationally feasible, and meaningful research design. The authors present an evaluation study design, provide an empirical example, and discuss considerations for generating the evidence base for ACO implementation. A quasi-experimental study design using propensity score matching in combination with small-scale exact matching is implemented. Outcome indicators based on claims data were constructed and analyzed. Population health is measured by using a range of mortality indicators: mortality ratio, age at time of death, years of potential life lost/gained, and survival time. The application is assessed using longitudinal data from Gesundes Kinzigtal, one of the leading population-based ACOs in Germany. The proposed matching approach resulted in a balanced control of observable differences between the intervention (ACO) and control groups. The mortality indicators used indicate positive results. For example, 635.6 fewer years of potential life lost (2005.8 vs. 2641.4; t-test: sig. P < 0.05*) in the ACO intervention group (n = 5411) attributable to the ACO, also after controlling for a potential (indirect) immortal time bias by excluding the first half year after enrollment from the outcome measurement. This empirical example of the impact of a German ACO on population health can be extended to the evaluation of ACOs and other integrated delivery models of care.
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Reeves, Barnaby C; Wells, George A; Waddington, Hugh
2017-09-01
The aim of the study was to extend a previously published checklist of study design features to include study designs often used by health systems researchers and economists. Our intention is to help review authors in any field to set eligibility criteria for studies to include in a systematic review that relate directly to the intrinsic strength of the studies in inferring causality. We also seek to clarify key equivalences and differences in terminology used by different research communities. Expert consensus meeting. The checklist comprises seven questions, each with a list of response items, addressing: clustering of an intervention as an aspect of allocation or due to the intrinsic nature of the delivery of the intervention; for whom, and when, outcome data are available; how the intervention effect was estimated; the principle underlying control for confounding; how groups were formed; the features of a study carried out after it was designed; and the variables measured before intervention. The checklist clarifies the basis of credible quasi-experimental studies, reconciling different terminology used in different fields of investigation and facilitating communications across research communities. By applying the checklist, review authors' attention is also directed to the assumptions underpinning the methods for inferring causality. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.
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May, Douglas R; Reed, Kendra; Schwoerer, Catherine E; Potter, Paul
2004-04-01
A naturally occurring quasi-experimental longitudinal field study of 87 municipal employees using pretest and posttest measures investigated the effects of an office workstation ergonomics intervention program on employees' perceptions of their workstation characteristics, levels of persistent pain, eyestrain, and workstation satisfaction. The study examined whether reactions differed between younger and older employees. Results revealed that workstation improvements were associated with enhanced perceptions of the workstation's ergonomic qualities, less upper back pain, and greater workstation satisfaction. Among those experiencing an improvement, the perceptions of workstation ergonomic qualities increased more for younger than older employees, supporting the "impressionable years" framework in the psychological literature on aging. Implications for human resources managers are discussed.
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Chiang, Chun-Ying; Sun, Fan-Ko
2009-01-01
Hypertension is known to have high rates among Chinese Americans. Identifying culturally specific interventions to reduce sedentary behavior may be effective in reducing hypertension. This study examines the effects of an 8-week walking program with and without cultural modification. The study used a 2-group, pretest and posttest, quasi-experimental design. A total sample of 128 Chinese American immigrants with hypertension were assigned to walking groups. The results showed that the walking program had no significant effects upon participant blood pressure or walking endurance. The results also revealed that individuals in the maintenance stage walked longer than those in the preparation stage. A comparison of demographic data showed that subjects with a lower level of education walked more minutes per week, which contributed to lower systolic blood pressures among this group as compared with those with a higher level of education. These results suggest that this walking protocol, when translated into Chinese and when accompanied by a weekly telephone reminder and other interactions with a Chinese-speaking nurse, is appropriate to use without additional cultural modification. Future research should examine other components of Chinese culture or should apply this protocol for a longer period of time.
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Effects of International Student Exchange on Pre-Service Teachers: A Quasi-Experimental Study
ERIC Educational Resources Information Center
Leutwyler, Bruno; Meierhans, Claudia
2016-01-01
This contribution provides empirical answers to the question of how teaching-specific competencies develop during participation in an international student exchange programme. The quantitative analyses of this quasi-experimental study suggest that, generally speaking, no specific developments occur during an exchange experience. These findings…
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ERIC Educational Resources Information Center
Long, Russell L.
2014-01-01
The purpose of this study was to offer evidence for the development of student character through the integration of historical storytelling into a social studies classroom. A quasi-experimental study was conducted to determine the effect of character education through historical storytelling integrated into a United States history curriculum on…
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ERIC Educational Resources Information Center
Pahnke, Johan; Lundgren, Tobias; Hursti, Timo; Hirvikoski, Tatja
2014-01-01
Autism spectrum disorder is characterized by social impairments and behavioural inflexibility. In this pilot study, the feasibility and outcomes of a 6-week acceptance and commitment therapy-based skills training group were evaluated in a special school setting using a quasi-experimental design (acceptance and commitment therapy/school classes as…
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Experimental quasi-single-photon transmission from satellite to earth.
Yin, Juan; Cao, Yuan; Liu, Shu-Bin; Pan, Ge-Sheng; Wang, Jin-Hong; Yang, Tao; Zhang, Zhong-Ping; Yang, Fu-Min; Chen, Yu-Ao; Peng, Cheng-Zhi; Pan, Jian-Wei
2013-08-26
Free-space quantum communication with satellites opens a promising avenue for global secure quantum network and large-scale test of quantum foundations. Recently, numerous experimental efforts have been carried out towards this ambitious goal. However, one essential step--transmitting single photons from the satellite to the ground with high signal-to-noise ratio (SNR) at realistic environments--remains experimental challenging. Here, we report a direct experimental demonstration of the satellite-ground transmission of a quasi-single-photon source. In the experiment, single photons (~0.85 photon per pulse) are generated by reflecting weak laser pulses back to earth with a cube-corner retro-reflector on the satellite CHAMP, collected by a 600-mm diameter telescope at the ground station, and finally detected by single-photon counting modules after 400-km free-space link transmission. With the help of high accuracy time synchronization, narrow receiver field-of-view and high-repetition-rate pulses (76 MHz), a SNR of better than 16:1 is obtained, which is sufficient for a secure quantum key distribution. Our experimental results represent an important step towards satellite-ground quantum communication.
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Laser pulse shape design for laser-indirect-driven quasi-isentropic compression experiments
NASA Astrophysics Data System (ADS)
Xue, Quanxi; Jiang, Shaoen; Wang, Zhebin; Wang, Feng; Zhao, Xueqing; Ding, Yongkun
2018-02-01
Laser pulse shape design is a key work in the design of indirect-laser-driven experiments, especially for long pulse laser driven quasi-isentropic compression experiments. A method for designing such a laser pulse shape is given here. What's more, application experiments were performed, and the results of a typical shot are presented. At last of this article, the details of the application of the method are discussed, such as the equation parameter choice, radiation ablation pressure expression, and approximations in the method. The application shows that the method can provide reliable descriptions of the energy distribution in a hohlraum target; thus, it can be used in the design of long-pulse laser driven quasi-isentropic compression experiments and even other indirect-laser-driven experiments.
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Gao, Hui; Li, Yang; Chen, Lianwei; Jin, Jinjin; Pu, Mingbo; Li, Xiong; Gao, Ping; Wang, Changtao; Luo, Xiangang; Hong, Minghui
2018-01-03
The quasi-Talbot effect of orbital angular momentum (OAM) beams, in which the centers are placed in a rotationally symmetric position, is demonstrated both numerically and experimentally for the first time. Since its multiplication factor is much higher than the conventional fractional Talbot effect, the quasi-Talbot effect can be used in the generation of vortex beam arrays. A metasurface based on this theory was designed and fabricated to test the validity of this assumption. The agreement between the numerical and measured results suggests the practicability of this method to realize vortex beam arrays with high integrated levels, which can open a new door to achieve various potential uses related to optical vortex arrays in integrated optical systems for wide-ranging applications.
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Trads, Mette; Deutch, Søren Rasmussen; Pedersen, Preben Ulrich
2017-09-07
The prevalence of constipation in the general population is 2-28%. Patients with constipation report symptoms of abdominal pain, bloating, nausea, straining to defecate and general discomfort. Strategies for preventing constipation include laxatives, exercise and increased fluid and fibre intake, but life style adjustments, such as exercise, eating more fibres and drinking more fluids, were not considered a solution by older patients. Previous studies have shown that actively involving patients through individualised care and support increases patients' outcome. To test the efficacy of a nursing intervention based on active patient involvement including individualised nursing care plans and daily dialogues for patients with hip fractures in preventing constipation after surgery. A quasi-experimental design was applied. Inclusion criteria hip fracture needing surgery, understand Danish. Exclusion criteria dementia, gastrointestinal disease. A total of 186 patients were included and 155 completed. An admission interview including Constipation Risk Assessment Scale was undertaken. On that basis an individualised nursing care plan was made. At admission, discharge and 30 days after surgery constipation, intake of fibres and fluid were measured. The Bristol Stool Scale and Rasmussen's scale were used to measure constipation. Patients in the control group received standard care of the ward. After 30 days constipation rates for patients in the intervention group were significantly lower than for patients in the control group (p = 0.042). The fibre intakes and fluid intakes were significantly higher in the intervention group (p ≤ 0.001). The effect of liquid intake was statistically significant (OR = 1.1, 95% CI: 1.0-1.2). Likewise, the effect of fibre intake was statistically significant; the odds of constipation decreased with increasing fibre intake (OR = 0.4, 95% CI: 0.2-0.8). Patients with hip fractures that were actively involved in their own care in preventing
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A comparison of the calculated and experimental off-design performance of a radial flow turbine
NASA Technical Reports Server (NTRS)
Tirres, Lizet
1992-01-01
Off design aerodynamic performance of the solid version of a cooled radial inflow turbine is analyzed. Rotor surface static pressure data and other performance parameters were obtained experimentally. Overall stage performance and turbine blade surface static to inlet total pressure ratios were calculated by using a quasi-three dimensional inviscid code. The off design prediction capability of this code for radial inflow turbines shows accurate static pressure prediction. Solutions show a difference of 3 to 5 points between the experimentally obtained efficiencies and the calculated values.
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A comparison of the calculated and experimental off-design performance of a radial flow turbine
NASA Technical Reports Server (NTRS)
Tirres, Lizet
1991-01-01
Off design aerodynamic performance of the solid version of a cooled radial inflow turbine is analyzed. Rotor surface static pressure data and other performance parameters were obtained experimentally. Overall stage performance and turbine blade surface static to inlet total pressure ratios were calculated by using a quasi-three dimensional inviscid code. The off design prediction capability of this code for radial inflow turbines shows accurate static pressure prediction. Solutions show a difference of 3 to 5 points between the experimentally obtained efficiencies and the calculated values.
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Full three-dimensional isotropic carpet cloak designed by quasi-conformal transformation optics.
Silva, Daniely G; Teixeira, Poliane A; Gabrielli, Lucas H; Junqueira, Mateus A F C; Spadoti, Danilo H
2017-09-18
A fully three-dimensional carpet cloak presenting invisibility in all viewing angles is theoretically demonstrated. The design is developed using transformation optics and three-dimensional quasi-conformal mapping. Parametrization strategy and numerical optimization of the coordinate transformation deploying a quasi-Newton method is applied. A discussion about the minimum achievable anisotropy in the 3D transformation optics is presented. The method allows to reduce the anisotropy in the cloak and an isotropic medium could be considered. Numerical simulations confirm the strategy employed enabling the design of an isotropic reflectionless broadband carpet cloak independently of the incident light direction and polarization.
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Historic and Ethnic Music Found to Increase Geographic Understanding: A Quasi-Experimental Study
ERIC Educational Resources Information Center
Richardson, Ronald; Brouillette, Liane
2013-01-01
This article summarizes a quasi-experimental study, which demonstrated that integration of historic and ethnic music into the American history curriculum may lead to increased knowledge of the cultural and physical geography of the United States as well as enhanced student engagement. An experiment (n = 215) conducted with eighth grade students…
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ERIC Educational Resources Information Center
Stellmack, Mark A.
2013-01-01
Studies of the effects of class attendance on class performance typically are quasi-experimental because students choose whether or not to attend class; that is, the samples are self-selecting. The lack of random assignment prevents one from establishing a causal relationship between attendance and performance. Relating attendance to performance…
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Halldorsson, Brynjar; Salkovskis, Paul M
2017-11-01
Cognitive behavioural interventions for excessive reassurance seeking (ERS) typically focus on encouraging individuals to refrain from seeking any reassurance and in some cases banning caregivers (e.g. family members) from providing it. However, this blanket consideration that reassurance is a bad thing that should simply be stopped may not always be appropriate or helpful. Cognitive behavioural treatment (CBT) targeting ERS by helping the sufferer to shift from seeking reassurance to seeking support may be a promising treatment intervention. This study aims to examine the targeted treatment of ERS in an older adult who has been suffering from severe obsessive compulsive disorder (OCD) for seven decades. Using a single case quasi-experimental design (ABCD), the frequency of reassurance seeking, urges to seek reassurance, OCD beliefs and anxiety were measured daily for almost a year in addition to standard symptom measures. At the end of treatment, visual inspection showed that reassurance seeking was no longer considered excessive and OCD severity fell from the severe to non-clinical range across the treatment sessions. All treatment gains were maintained at follow-up. This study illustrates how CBT can be successfully applied to treat long-standing OCD and ERS in an older adult. Engendering support as an alternative to reassurance seeking in CBT may be a particularly promising intervention for ERS.
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Orem's Self-Care Model With Trauma Patients: A Quasi-Experimental Study.
Khatiban, Mahnaz; Shirani, Fatemeh; Oshvandi, Khodayar; Soltanian, Ali Reza; Ebrahimian, Ramin
2018-07-01
To examine if the application of Orem's self-care model could improve self-care knowledge, attitudes, practices, and respiratory conditions of trauma patients with chest tubes, a quasi-experimental study was conducted. The participants were assigned to two groups-namely, Orem's model and routine care. Although the patients' self-care knowledge, attitudes, and practices were improved in both groups over the course of 3 days since the initial assessments, there was a greater degree of improvement in the experimental group than that in the control group. However, there were no differences in the improvement of the chest parameters between the two groups. Orem's model was effective in improving self-care in patients with chest tube.
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Verberne, Lisa D M; Hendriks, Marike R C; Rutten, Geert M; Spronk, Inge; Savelberg, Hans H C M; Veenhof, Cindy; Nielen, Mark M J
2016-12-01
Combined lifestyle interventions (CLIs) are designed to reduce risk factors for lifestyle-related diseases through increasing physical activity and improvement of dietary behaviour. To evaluate the effects of a CLI for overweight and obese patients on lifestyle-related risk factors and health care consumption, in comparison to usual care. Data on anthropometric and metabolic measurements, morbidity, drugs prescriptions and general practitioner (GP) consultations were extracted from electronic health records (timeframe: July 2009-August 2013). Using a quasi-experimental design, health outcomes of 127 patients who participated in a 1-year CLI were compared to a group of 254 matched patients that received usual care. Baseline to post-intervention changes in health outcomes between intervention and comparison group were evaluated using mixed model analyses. Compared to baseline, both groups showed reductions in body mass index (BMI), blood pressure, total cholesterol and low density lipoprotein cholesterol in year post-intervention. For these outcome measures, no significant differences in changes were observed between intervention and comparison group. A significant improvement of 0.08 mmol/l in high density lipoprotein (HDL) cholesterol was observed for the intervention group above the comparison group (P < 0.01). No significant intergroup differences were shown in drugs prescriptions and number of GP consultations. A CLI for overweight and obese patients in primary health care resulted in similar effects on health outcomes compared to usual care. Only an improvement on HDL cholesterol was shown. This study indicates that implementation and evaluation of a lifestyle intervention in primary health care is challenging due to political and financial barriers. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
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Quasi-Phase-Matched Supercontinuum Generation in Photonic Waveguides
NASA Astrophysics Data System (ADS)
Hickstein, Daniel D.; Kerber, Grace C.; Carlson, David R.; Chang, Lin; Westly, Daron; Srinivasan, Kartik; Kowligy, Abijith; Bowers, John E.; Diddams, Scott A.; Papp, Scott B.
2018-02-01
Supercontinuum generation (SCG) in integrated photonic waveguides is a versatile source of broadband light, and the generated spectrum is largely determined by the phase-matching conditions. Here we show that quasi-phase-matching via periodic modulations of the waveguide structure provides a useful mechanism to control the evolution of ultrafast pulses during supercontinuum generation. We experimentally demonstrate a quasi-phase-matched supercontinuum to the TE20 and TE00 waveguide modes, which enhances the intensity of the SCG in specific spectral regions by as much as 20 dB. We utilize higher-order quasi-phase-matching (up to the 16th order) to enhance the intensity in numerous locations across the spectrum. Quasi-phase-matching adds a unique dimension to the design space for SCG waveguides, allowing the spectrum to be engineered for specific applications.
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Feicke, Janine; Spörhase, Ulrike; Köhler, Jürgen; Busch, Claudia; Wirtz, Markus
2014-12-01
To determine the impact of the self-management training program "S.MS" for new multiple sclerosis (MS) patients. Multicenter, prospective, quasi-experimental study with 31 MS patients in the intervention group (training program) and 33 participants in the control group (CG) (brochures). Data were collected before, after and 6 months after the interventions. Analysis of change was done by ANCOVA with repeated measurements. At baseline, participants in CG were younger at the time of diagnosis, suffered more frequently from relapsing-remitting MS and took more MS-medication on a permanent basis. The intervention had a stable significant effect on each dimension of self-management ability, on total self-management ability (ES=0.194, p<0.001), on anxiety (ES=0.193, p=0.001), and on disease-specific quality of life (ES=0.120, p=0.007). Regarding depression, a significant interaction effect of time and intervention could be observed (ES=0.106, p=0.011). No effect was found on disease-specific knowledge. High participant acceptance was reported. "S.MS" participation was associated with a significant and sustained improvement of self-management abilities, anxiety and disease-specific quality of life in a quasi-experimental study design. Using RCT or CRT-designs would be desirable to further improve the evidence of treatment effectiveness. This study provides substantial evidence that "S.MS" fosters patients' self-management ability. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.
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Convergence of the Quasi-static Antenna Design Algorithm
2013-04-01
was the first antenna design with quasi-static methods. In electrostatics, a perfect conductor is the same as an equipotential surface . A line of...which can cause the equipotential surface to terminate on the disk or feed wire. This requires an additional step in the solution process; the... equipotential surface is sampled to verify that the charge is enclosed by the equipotential surface . The final solution must be verified with a detailed
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Design and quasi-static characterization of SMASH (SMA stabilizing handgrip)
NASA Astrophysics Data System (ADS)
Pathak, Anupam; Brei, Diann; Luntz, Jonathan; LaVigna, Chris; Kwatny, Harry
2007-04-01
Due to physiologically induced body tremors, there is a need for active stabilization in many hand-held devices such as surgical tools, optical equipment (cameras), manufacturing tools, and small arms weapons. While active stabilization has been achieved with electromagnetic and piezoceramics actuators for cameras and surgical equipment, the hostile environment along with larger loads introduced by manufacturing and battlefield environments make these approaches unsuitable. Shape Memory Alloy (SMA) actuators are capable of alleviating these limitations with their large force/stroke generation, smaller size, lower weight, and increased ruggedness. This paper presents the actuator design and quasi-static characterization of a SMA Stabilizing Handgrip (SMASH). SMASH is an antagonistically SMA actuated two degree-of-freedom stabilizer for disturbances in the elevation and azimuth directions. The design of the SMASH for a given application is challenging because of the difficulty in accurately modeling systems loads such as friction and unknown shakedown SMA material behavior (which is dependent upon the system loads). Thus, an iterative empirical design process is introduced that provides a method to estimate system loads, a SMA shakedown procedure using the system loads to reduce material creep, and a final selection and prediction for the full SMASH system performance. As means to demonstrate this process, a SMASH was designed, built and experimentally characterized for the extreme case study of small arms stabilization for a US Army M16 rifle. This study successfully demonstrated the new SMASH technology along with the unique design procedure that can be applied to small arms along with a variety of other hand-held devices.
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Commisso, Maria S; Martínez-Reina, Javier; Mayo, Juana; Domínguez, Jaime
2013-02-01
The main objectives of this work are: (a) to introduce an algorithm for adjusting the quasi-linear viscoelastic model to fit a material using a stress relaxation test and (b) to validate a protocol for performing such tests in temporomandibular joint discs. This algorithm is intended for fitting the Prony series coefficients and the hyperelastic constants of the quasi-linear viscoelastic model by considering that the relaxation test is performed with an initial ramp loading at a certain rate. This algorithm was validated before being applied to achieve the second objective. Generally, the complete three-dimensional formulation of the quasi-linear viscoelastic model is very complex. Therefore, it is necessary to design an experimental test to ensure a simple stress state, such as uniaxial compression to facilitate obtaining the viscoelastic properties. This work provides some recommendations about the experimental setup, which are important to follow, as an inadequate setup could produce a stress state far from uniaxial, thus, distorting the material constants determined from the experiment. The test considered is a stress relaxation test using unconfined compression performed in cylindrical specimens extracted from temporomandibular joint discs. To validate the experimental protocol, the test was numerically simulated using finite-element modelling. The disc was arbitrarily assigned a set of quasi-linear viscoelastic constants (c1) in the finite-element model. Another set of constants (c2) was obtained by fitting the results of the simulated test with the proposed algorithm. The deviation of constants c2 from constants c1 measures how far the stresses are from the uniaxial state. The effects of the following features of the experimental setup on this deviation have been analysed: (a) the friction coefficient between the compression plates and the specimen (which should be as low as possible); (b) the portion of the specimen glued to the compression plates (smaller
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A Quasi-Experimental Comparison of Student Satisfaction in Hybrid versus and Online-Only Course
ERIC Educational Resources Information Center
Griffith, John D.
2014-01-01
While online education is becoming more popular in the United States, there are a number of justifiable concerns with students adjusting to this particular learning environment. One of the concerns from a student's perspective is a sense of isolation. The purpose of this quantitative, quasi-experimental study was to investigate whether…
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Giroux, Dominique; Robichaud, Line; Paradis, Martin
2010-01-01
The choice of activities responding to the needs of people with moderate to severe dementia is a growing concern for care providers trying to target the need for a feeling of self-accomplishment by adapting activities to the abilities of elderly patients. The activities created by Maria Montessori seem to be adaptable to this clientele. This study evaluates the short-term effects, as compared to regular activities offered in the milieu. This is a quasi-experimental study where each of the 14 participants was observed and filmed in two conditions: during Montessori activities, during regular activities, and one control condition (no activity). The results show that Montessori activities have a significant effect on affect and on participation in the activity. They support the hypothesis that when activities correspond to the needs and abilities of a person with dementia, these positive effects are also observed on behaviours. This study enabled its authors to corroborate the findings presented in the literature and to contribute additional elements on the positive effects of the use of Montessori activities and philosophy. Used with people with moderate to severe dementia these allow the satisfaction of their basic psychological needs, their well being, and hence, on their quality of life.
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ERIC Educational Resources Information Center
Rienties, Bart; Héliot, YingFei
2018-01-01
While interdisciplinary courses are regarded as a promising method for students to learn and apply knowledge from other disciplines, there is limited empirical evidence available whether interdisciplinary courses can effectively "create" interdisciplinary students. In this innovative quasi-experimental study amongst 377 Master's…
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Educational intervention for collecting sputum for tuberculosis: a quasi-experimental study 1
Sicsú, Amélia Nunes; Salem, Julia Ignez; Fujimoto, Luciana Botinelly Mendonça; Gonzales, Roxana Isabel Cardozo; Cardoso, Maria do Socorro de Lucena; Palha, Pedro Fredemir
2016-01-01
Abstract Objective: to evaluate the quality of the sputum sample before and after the Nursing guidance to patients. Methods: this is a quasi-experimental research design, single group type, before and after, non-randomized study. The study enrolled patients with suspected pulmonary tuberculosis, respiratory symptomatic patients for over three weeks, aged over 18 years, of both genders and without tuberculosis history in the last two years. The educational intervention consisted of individualized guidance on the collection of sputum sample, which was based on the guidelines of the Ministry of Health of Brazil and on the explanatory folder delivery. Results: in this study participated 138 patients with suspected pulmonary tuberculosis. The results showed significant increase of the samples with purulent particles, volume greater than 5 mL and increased rate of patients diagnosed with tuberculosis, after the educational intervention. Conclusion: it was shown that after the educational intervention, it was observed sputum samples with better quality, with satisfactory aspect and volume for the effectiveness of the bacilloscopic examination. PMID:27276015
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A quasi-experimental study of after-event reviews and leadership development.
Derue, D Scott; Nahrgang, Jennifer D; Hollenbeck, John R; Workman, Kristina
2012-09-01
We examine how structured reflection through after-event reviews (AERs) promotes experience-based leadership development and how people's prior experiences and personality attributes influence the impact of AERs on leadership development. We test our hypotheses in a time-lagged, quasi-experimental study that followed 173 research participants for 9 months and across 4 distinct developmental experiences. Findings indicate that AERs have a positive effect on leadership development, and this effect is accentuated when people are conscientious, open to experience, and emotionally stable and have a rich base of prior developmental experiences.
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Maguire, Aideen; Rosato, Michael; O'Reilly, Dermot
2017-10-01
To determine if providing informal care to a co-resident with dementia symptoms places an additional risk on the likelihood of poor mental health or mortality compared with co-resident non-caregivers. A quasi-experimental design of caregiving and non-caregiving co-residents of individuals with dementia symptoms provides a natural comparator for the additive effects of caregiving on top of living with an individual with dementia symptoms. Census records, providing information on household structure, intensity of caregiving, presence of dementia symptoms and self-reported mental health were linked to mortality records over the following 33 months. Multi-level regression models were constructed to determine the risk of poor mental health and death in co-resident caregivers of individuals with dementia symptoms compared with co-resident non-caregivers, adjusting for the clustering of individuals within households. The cohort consisted of 10 982 co-residents (55.1% caregivers), with 12.1% of non-caregivers reporting poor mental health compared with 8.4% of intense caregivers (>20 h of care per week). During follow-up, the cohort experienced 560 deaths (245 to caregivers). Overall, caregiving co-residents were at no greater risk of poor mental health but had lower mortality risk than non-caregiving co-residents (adjusted odds ratio (ORadj) = 0.93, 95% confidence interval (CI) 0.79, 1.10 and ORadj = 0.67, 95% CI 0.56, 0.81, respectively); this lower mortality risk was also seen amongst the most intensive caregivers (ORadj = 0.65, 95% CI 0.53, 0.79). Caregiving poses no additional risk to mental health over and above the risk associated with merely living with someone with dementia and is associated with a lower mortality risk compared with non-caregiving co-residents. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.
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Larsson, Henrik
2016-04-01
Standard observational studies have reported a robust correlation between maternal smoking during pregnancy and risk of ADHD in offspring. In the accompanying article, Obel et al. used sibling-comparisons to explore the extent to which unmeasured familial confounding explains this association. This commentary highlights three important implications of the study. At a general level, Obel et al. illustrates how (1) family-based quasi-experimental designs and (2) national registers can be used to address confounding in risk factor studies of psychopathology. At a more specific level, the study suggests that maternal smoking during pregnancy is probably not a causal risk factor for ADHD. © 2016 Association for Child and Adolescent Mental Health.
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Riemersma, Ivon; van Santvoort, Floor; Janssens, Jan M A M; Hosman, Clemens M H; van Doesum, Karin T M
2015-12-24
Children of parents with a mental illness or substance use disorder (COPMI) have an increased risk of developing social-emotional problems themselves. Fear of stigmatisation or unawareness of problems prevents children and parents from understanding each other. Little is known about COPMI with mild intellectual disabilities (ID), except that they have a high risk of developing social-emotional problems and require additional support. In this study, we introduce a program for this group, the effectiveness of which we will study using a quasi-experimental design based on matching. The program 'You are okay' consists of a support group for children and an online educational program for parents. The goal of the program is to increase children and parents' perceived competence with an aim to prevent social-emotional problems in children. Children between ten and twenty years old with mild ID (IQ between 50 and 85) and at least one of their parents with a mental illness will be included in the study. The children will receive part time treatment or residential care from an institute for children with mild ID and behavioural problems. Participants will be assigned to the intervention or the control group. The study has a quasi-experimental design. The children in the intervention group will join a support group, and their parents will be offered an online educational program. Children in the control group will receive care as usual, and their parents will have no extra offer. Assessments will be conducted at baseline, post-test, and follow up (6 months). Children, parents, and social workers will fill out the questionnaires. The 'You are okay' program is expected to increase children and parents' perceived competence, which can prevent (further) social-emotional problem development. Because the mental illness of parents can be related to the behavioural problems of their children, it is important that children and parents understand each other. When talking about the
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ERIC Educational Resources Information Center
Karazsia, Bryan T.; Wong, Kendal
2016-01-01
Quantitative and statistical literacy are core domains in the undergraduate psychology curriculum. An important component of such literacy includes interpretation of visual aids, such as tables containing results from statistical analyses. This article presents results of a quasi-experimental study with longitudinal follow-up that tested the…
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Length of perineal pain relief after ice pack application: A quasi-experimental study.
de Souza Bosco Paiva, Caroline; Junqueira Vasconcellos de Oliveira, Sonia Maria; Amorim Francisco, Adriana; da Silva, Renata Luana; de Paula Batista Mendes, Edilaine; Steen, Mary
2016-04-01
Ice pack is effective for alleviating postpartum perineal pain in primiparous women while multiparous women's levels of perineal pain appear to be poorly explored. Ice pack is a low-cost non-invasive localised treatment that can be used with no impact on breastfeeding. However, how long perineal analgesia persists after applying an ice pack is still unknown. To evaluate if perineal analgesia is maintained up to 2h after applying an ice pack to the perineum for 20min. A quasi-experimental study, using a pre and post-test design, was undertaken with a sample size of 50 multiparous women in Brazil. Data was collected by structured interview. The intervention involved a single application of an ice pack applied for 20min to the perineal area of women who reported perineal pain ≥3 by use of a numeric rating scale (0-10), with intact perineum, 1st or 2nd degree lacerations or episiotomy, between 6 and 24h after spontaneous vaginal birth. Perineal pain was evaluated at three points of time: before, immediately after and 2h after applying an ice pack. Immediately after applying an ice pack to the perineal area, there was a significant reduction in the severity of perineal pain reported (5.4 vs. 1.0, p<0.0005), which continued for 1h 35min up to 2h after the local application. Ice pack application for 20min is effective for alleviating postpartum perineal pain and continues to be effective between 1h 35min for up to 2h. Copyright © 2015 Australian College of Midwives. Published by Elsevier Ltd. All rights reserved.
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Wong, Arkers Kwan Ching; Wong, Frances Kam Yuet; Chan, Lap Ki; Chan, Namkiu; Ganotice, Fraide A; Ho, Jacqueline
2017-06-01
Although interprofessional education has received attention in recent years as a means of providing opportunities for health-care professionals to learn with, from and about other disciplines and enhance the quality of patient care, evidence of its effectiveness is limited. Interprofessional team-based learning was introduced to make it possible for students in different healthcare disciplines to interact with each other, and to prepare them to function effectively within a team in their future career. To examine the effects of interprofessional team-based learning for undergraduate nursing students in terms of knowledge level, readiness for interprofessional learning, attitude towards various aspects of team learning, and perceived collective efficacy. The study employed a one-group pretest-posttest quasi-experimental design. An interprofessional education program was given to students from two universities in Hong Kong who were in different healthcare disciplines including medicine, nursing, pharmacy, biomedical science, and Chinese medicine programs. The program was based on four phases of student learning- individual readiness assessment test, ice breaking session, team readiness assessment test, and application exercise. Nursing students involved in the program were invited to complete anonymous questionnaires to evaluate their interprofessional team experience. A total of 40 nursing students (9 male, 31 female) participated in the study. A statistically significant improvement was identified in their knowledge level (p<0.001), attitude towards readiness for interprofessional learning, team learning, and perceived collective efficacy (p<0.001). This study suggests that interprofessional team-based learning can enhance cross-disciplinary learning and outcomes resulting from team efforts. Copyright © 2017 Elsevier Ltd. All rights reserved.
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Study of a quasi-microscope design for planetary landers
NASA Technical Reports Server (NTRS)
Giat, O.; Brown, E. B.
1973-01-01
The Viking Lander fascimile camera, in its present form, provides for a minimum object distance of 1.9 meters, at which distance its resolution of 0.0007 radian provides an object resolution of 1.33 millimeters. It was deemed desirable, especially for follow-on Viking missions, to provide means for examing Martian terrain at resolutions considerably higher than that now provided. This led to the concept of quasi-microscope, an attachment to be used in conjunction with the fascimile camera to convert it to a low power microscope. The results are reported of an investigation to consider alternate optical configurations for the quasi-microscope and to develop optical designs for the selected system or systems. Initial requirements included consideration of object resolutions in the range of 2 to 50 micrometers, an available field of view of the order of 500 pixels, and no significant modifications to the fascimile camera.
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2014-01-01
Background New high-voltage power transmission lines will be introduced due to increasing demand for reliable and renewable energy supplies. Some residents associate non-specific health complaints with exposure to electromagnetic fields from nearby power lines. This study protocol describes the design and rationale of a prospective study investigating whether the introduction of a new power line triggers health responses in residents living nearby. Methods/Design The study is designed as a quasi-experimental field study with two pretests during the construction of a new power line route, and two posttests after it has been put into operation. Key outcomes are self-reported non-specific somatic and cognitive health complaints, and attribution of these health complaints to a power line. The main determinant is proximity to the new power line route. One member of every household (n = 2379) residing in close proximity (0-500 meters) to the overhead parts of a new power line route in the Netherlands is invited to participate, as well as a sample of household members (n = 2382) residing farther away (500-2000 meters). Multilevel analysis will be employed to test whether an increase in key outcome measures is related to proximity to the line. Longitudinal structural equation models will be applied to test to what extent health responses are mediated by psychosocial health mechanisms and moderated by negative oriented personality traits. Discussion This is the first study to investigate health responses to a new power line route in a prospective manner. The results will provide theoretical insight into psychosocial mechanisms operating during the introduction of an environmental health risk, and may offer suggestions to policymakers and other stakeholders for minimizing adverse health responses when introducing new high-voltage power lines. PMID:24606914
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Methodological convergence of program evaluation designs.
Chacón-Moscoso, Salvador; Anguera, M Teresa; Sanduvete-Chaves, Susana; Sánchez-Martín, Milagrosa
2014-01-01
Nowadays, the confronting dichotomous view between experimental/quasi-experimental and non-experimental/ethnographic studies still exists but, despite the extensive use of non-experimental/ethnographic studies, the most systematic work on methodological quality has been developed based on experimental and quasi-experimental studies. This hinders evaluators and planners' practice of empirical program evaluation, a sphere in which the distinction between types of study is changing continually and is less clear. Based on the classical validity framework of experimental/quasi-experimental studies, we carry out a review of the literature in order to analyze the convergence of design elements in methodological quality in primary studies in systematic reviews and ethnographic research. We specify the relevant design elements that should be taken into account in order to improve validity and generalization in program evaluation practice in different methodologies from a practical methodological and complementary view. We recommend ways to improve design elements so as to enhance validity and generalization in program evaluation practice.
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Kang, Jung Sun; Choi, So Young; Ryu, Eun Jung
2008-01-01
This quasi-experimental study examined the effects of a new breastfeeding empowerment programme provided to post-partum mothers within 3 days of entering post-partum care centres on their breastfeeding empowerment, problems and practice rate. The study employed a non-equivalent control group non-synchronized design. Participants who conformed with the selection criteria were selected from two post-partum care centres affiliated with hospitals in a city in South Korea. Each of the two study groups included 30 participants. The breastfeeding empowerment programme comprised four 60-minute sessions, and was applied for 4 weeks to mothers in the experimental group. The breastfeeding empowerment scores were higher in the experimental group than in the control group (p=0.007), and there were fewer breastfeeding problems in the former group (p=0.012) and the breastfeeding rates were higher in the former group (p=0.017, 0.002 and 0.002 at 4, 8 and 12 weeks post-partum, respectively). These results indicate that the provision of breastfeeding empowerment programmes to help mothers to identify and solve problems by themselves can improve breastfeeding empowerment, problem and practice rates, and hence should be considered useful as a post-partum nursing intervention in clinical settings. The effectiveness of the various components of the breastfeeding empowerment programme developed in this study should be verified in field trials.
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NASA Astrophysics Data System (ADS)
Doganca Kucuk, Zerrin; Saysel, Ali Kerem
2017-03-01
A systems-based classroom intervention on environmental education was designed for seventh grade students; the results were evaluated to see its impact on the development of systems thinking skills and standard science achievement and whether the systems approach is a more effective way to teach environmental issues that are dynamic and complex. A quasi-experimental methodology was used to compare performances of the participants in various dimensions, including systems thinking skills, competence in dynamic environmental problem solving and success in science achievement tests. The same pre-, post- and delayed tests were used with both the comparison and experimental groups in the same public middle school in Istanbul. Classroom activities designed for the comparison group (N = 20) followed the directives of the Science and Technology Curriculum, while the experimental group (N = 22) covered the same subject matter through activities benefiting from systems tools and representations such as behaviour over time graphs, causal loop diagrams, stock-flow structures and hands-on dynamic modelling. After a one-month systems-based instruction, the experimental group demonstrated significantly better systems thinking and dynamic environmental problem solving skills. Achievement in dynamic problem solving was found to be relatively stable over time. However, standard science achievement did not improve at all. This paper focuses on the quantitative analysis of the results, the weaknesses of the curriculum and educational implications.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Cao, Qifo; Liu, Yong; Zhao, Hailin, E-mail: zhaohailin@ipp.ac.cn
A system to simultaneously diagnose the electron temperature and density fluctuations is proposed for Experimental Advanced Superconducting Tokamak device. This system includes a common quasi-optical antenna, a correlation electron cyclotron emission (CECE) system that is used to measure the electron temperature fluctuations and a Doppler backscattering (DBS) system that is used to measure the electron density fluctuations. The frequency range of the proposed CECE system is 108-120 GHz, and this corresponds to a radial coverage of normalized radius ((R − R{sub 0})/a, R{sub 0} = 1850 mm, a = 450 mm) from 0.2 to 0.67 for the plasma operation withmore » a toroidal magnetic field of 2.26 T. This paper focuses on the design of the quasi-optical antenna and aims at optimizing the poloidal resolution for different frequency bands. An optimum result gives the beam radius for the CECE system of 13-15 mm and this corresponds to a wave number range of k{sub θ} < 2.4 cm{sup −1}. The beam radius is 20-30 mm for V band (50-75 GHz) and 15-20 mm for W band (75-110 GHz).« less
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Pålsson, Ylva; Mårtensson, Gunilla; Swenne, Christine Leo; Ädel, Eva; Engström, Maria
2017-04-01
Studies of peer learning indicate that the model enables students to practice skills useful in their future profession, such as communication, cooperation, reflection and independence. However, so far most studies have used a qualitative approach and none have used a quasi-experimental design to study effects of nursing students' peer learning in clinical practice. To investigate the effects of peer learning in clinical practice education on nursing students' self-rated performance. Quasi-experimental. The study was conducted during nursing students' clinical practice. All undergraduate nursing students (n=87) attending their first clinical practice were approached. Seventy students out of 87 answered the questionnaires at both baseline and follow-up (42 of 46 in the intervention group and 28 of 39 in the comparison group). During the first two weeks of the clinical practice period, all students were supervised traditionally. Thereafter, the intervention group received peer learning the last two weeks, and the comparison group received traditional supervision. Questionnaire data were collected on nursing students' self-rated performance during the second (baseline) and last (follow-up) week of their clinical practice. Self-efficacy was improved in the intervention group and a significant interaction effect was found for changes over time between the two groups. For the other self-rated variables/tests, there were no differences in changes over time between the groups. Studying each group separately, the intervention group significantly improved on thirteen of the twenty variables/tests over time and the comparison group improved on four. The results indicate that peer learning is a useful method which improves nursing students' self-efficacy to a greater degree than traditional supervision does. Regarding the other self-rated performance variables, no interaction effects were found. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.
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A Quasi-Experimental Evaluation of an On-Line Formative Assessment and Tutoring System
ERIC Educational Resources Information Center
Koedinger, Kenneth R.; McLaughlin, Elizabeth A.; Heffernan, Neil T.
2010-01-01
ASSISTments is a web-based math tutor designed to address the need for timely student assessment while simultaneously providing instruction, thereby avoiding lost instruction time that typically occurs during assessment. This article presents a quasi-experiment that evaluates whether ASSISTments use has an effect on improving middle school…
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Chang, Beh-Huan; Chen, Bo-Wei; Beckstead, Jason W; Yang, Chiu-Yueh
2018-06-01
Many studies have shown that music therapy improves patients' symptoms. However, interventions using music creation as their core await further development for patients with severe mental illness (SMI). The current study investigated the effect of a music-creation programme on the anxiety, self-esteem, and quality of life of patients with SMI. A quasi-experimental design using convenience sampling was adopted to recruit patients with SMI from a psychiatric day care centre. Participants were grouped based on their willingness to undergo an intervention (26 patients in the experimental group and 23 patients in the control group). The control groups participated in conventional mental rehabilitation therapy activities. The experimental group participated in a music-creation session for 90 min every week over a 32-week period. The outcome indicators before and after the intervention were assessed using the Hamilton Anxiety Rating Scale (HAM-A), Rosenberg Self-Esteem Scale (RSES), and World Health Organization Quality of Life-BREF (WHOQOL-BREF). Finally, the intervention effect was determined using generalized estimating equations (GEEs). After 32 weeks of intervention activities, the experimental group showed significant improvements in their HAM-A total scores (P < 0.001) and RSES total scores (P = 0.005). Regarding quality of life, the improvements of the experimental group in terms of the psychological (P = 0.016) and social relationship domains (P = 0.033) were superior to those of the control group. Music-creation programmes are recommended for inclusion in the routine rehabilitation activities of patients with SMI. © 2017 Australian College of Mental Health Nurses Inc.
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Quasi-Experimental Evidence of Peer Effects in First-Year Economics Courses at a Chinese University
ERIC Educational Resources Information Center
Chen, Qihui; Tian, Guoqiang; Okediji, Tade O.
2014-01-01
The authors of this article implement a quasi-experimental strategy to estimate peer effects in economic education by exploiting the institutional setting in a large public university in China, where roommates are randomly assigned conditional on a student's major and province of origin. They found significant impacts of peer academic quality,…
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ERIC Educational Resources Information Center
Evans, Retta R.; Horton, Jacqueline A.; Ahmad, Wajih A.; Davies, Susan L.; Snyder, Scott W.; Macrina, David M.
2013-01-01
Purpose: A breast health educational program was administered in two public high school settings in north Alabama to subjects enrolled in health related courses. The purpose of this quasi-experimental study was to determine if teaching breast health with or without interactive learning would affect the breast health knowledge and beliefs of…
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Nierkens, Vera; Kunst, Anton E; De Vries, Hein; Voorham, Toon A J; Stronks, Karien
2013-01-01
Community interventions have been considered promising strategies to reduce smoking prevalence among ethnic minority populations. We assessed the reach and effectiveness of a community program targeted at the Turkish population in Rotterdam, the Netherlands. The study had a quasi-experimental design, with 1 pretest and 1 posttest among 18- to 60-year-old Turkish residents in a district in Rotterdam (n = 388 at pretest) and in a comparison area in the city of Utrecht (n = 389 at pretest). The surveys included measures of reach and measures of effectiveness. Logistic regression analysis assessed changes in the outcome measures over time, adjusting for sex, age, and educational level. At posttest, more smokers (62.5%) perceived pros of quitting, and 8.2% had quit. Compared with the comparison group, in the intervention group the changes tended to be greater, but differences were not statistically significant. Of all respondents, 61.2% recognized at least 1 program component, and 23.1% participated in at least 1. Based on the greater changes in the intervention group (particularly regarding quit rates and pros of smoking), this community intervention can become a promising strategy. To increase potential effectiveness, participation rates need to increase and interventions should last longer and include smoking-cessation support.
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Van Kann, Dave H H; Jansen, M W J; de Vries, S I; de Vries, N K; Kremers, S P J
2015-12-29
The worldwide increase in the rates of childhood overweight and physical inactivity requires successful prevention and intervention programs for children. The aim of the Active Living project is to increase physical activity and decrease sedentary behavior of Dutch primary school children by developing and implementing tailored, multicomponent interventions at and around schools. In this project, school-centered interventions have been developed at 10 schools in the south of the Netherlands, using a combined top-down and bottom-up approach in which a research unit and a practice unit continuously interact. The interventions consist of a combination of physical and social interventions tailored to local needs of intervention schools. The process and short- and long-term effectiveness of the interventions will be evaluated using a quasi-experimental study design in which 10 intervention schools are matched with 10 control schools. Baseline and follow-up measurements (after 12 and 24 months) have been conducted in grades 6 and 7 and included accelerometry, GPS, and questionnaires. Primary outcome of the Active Living study is the change in physical activity levels, i.e. sedentary behavior (SB), light physical activity (LPA), moderate-to-vigorous physical activity (MVPA), and counts-per-minute (CPM). Multilevel regression analyses will be used to assess the effectiveness of isolated and combined physical and social interventions on children's PA levels. The current intervention study is unique in its combined approach of physical and social environmental PA interventions both at school(yard)s as well as in the local neighborhood around the schools. The strength of the study lies in the quasi-experimental design including objective measurement techniques, i.e. accelerometry and GPS, combined with more subjective techniques, i.e. questionnaires, implementation logbooks, and neighborhood observations. Current Controlled Trials ISRCTN25497687 (registration date 21
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Optimized emission in nanorod arrays through quasi-aperiodic inverse design.
Anderson, P Duke; Povinelli, Michelle L
2015-06-01
We investigate a new class of quasi-aperiodic nanorod structures for the enhancement of incoherent light emission. We identify one optimized structure using an inverse design algorithm and the finite-difference time-domain method. We carry out emission calculations on both the optimized structure as well as a simple periodic array. The optimized structure achieves nearly perfect light extraction while maintaining a high spontaneous emission rate. Overall, the optimized structure can achieve a 20%-42% increase in external quantum efficiency relative to a simple periodic design, depending on material quality.
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Somers, Julian M; Moniruzzaman, Akm; Rezansoff, Stefanie N; Patterson, Michelle
2014-01-01
Problem solving courts (PSC) have been implemented internationally, with a common objective to prevent reoffending by addressing criminogenic needs and strengthening social determinants of health. There has been no empirical research on the effectiveness of community courts, which are a form of PSC designed to harness community resources and inter-disciplinary expertise to reduce recidivism in a geographic catchment area. We used the propensity score matching method to examine the effectiveness of Vancouver's Downtown Community Court (DCC). We focused on the subset of DCC participants who were identified as having the highest criminogenic risk and were assigned to a case management team (CMT). A comparison group was derived using one-to-one matching on a large array variables including static and dynamic criminogenic factors, geography, and time. Reductions in offences (one year pre minus one year post) were compared between CMT and comparison groups. Compared to other DCC offenders, those triaged to CMT (9.5% of the DCC population) had significantly higher levels of healthcare, social service use, and justice system involvement over the ten years prior to the index offence. Compared to matched offenders who received traditional court outcomes, those assigned to CMT (n=249) exhibited significantly greater reductions in overall offending (p<0.001), primarily comprised of significant reductions in property offences (p<0.001). Our findings indicate that CMT achieved significantly greater reductions in recidivism than traditional court among offenders with complex needs and high numbers of previous offences. Limitations of this research include a non-experimental design and one year follow up. Strengths include a robust matching process and extensive client level data spanning multiple sectors. Further research is needed to replicate the observed outcomes, to investigate the extension of community courts to settings with divergent offender needs and local resources
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A quasi-experimental investigation of message appeal variations on organ donor registration rates.
Siegel, Jason T; Alvaro, Eusebio M; Crano, William D; Lac, Andrew; Ting, Sarah; Jones, Sara Pace
2008-03-01
Approximately 6,000 Americans die every year awaiting an organ transplant. Health promotion interventions may alleviate the shortage of viable organs by increasing the number of registered organ donors. This study is the first to evaluate the differential effectiveness of various organ donor messages in naturalistic settings. A 4 (Appeal)x4 (Exemplar)x4 (Location) counterbalanced quasi-experimental design was implemented. The behavioral outcome measure was the number of individuals who registered to be organ donors at computer kiosks. A number of significant main effects and interactions emerged. Most notably, of the 4 different appeals (counterargument, emotional, motivating action, dissonance), counterargument was by far the most efficacious, especially in academic-type settings (library, university, community college); the emotional appeal was most successful in hospitals. The findings from this study have implications for both organ donor investigations and health campaign research in general. Statistical interactions highlight the importance of evaluating multiple exemplars in multiple locations for each type of appeal when conducting health campaign research. Copyright (c) 2008 APA, all rights reserved.
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ERIC Educational Resources Information Center
Powell, Tara; Thompson, Sanna J.
2016-01-01
Objective: This article presents the Journey of Hope (JoH), a school-based intervention for children who have experienced a collective trauma such as a natural disaster. Through the use of group work, the JoH focuses on building coping skills and enhancing protective factors to help children recover. Method: This quasi-experimental research…
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Sustaining a Global Social Network: a quasi-experimental study.
Benton, D C; Ferguson, S L
2017-03-01
To examine the longer term impact on the social network of participating nurses in the Global Nursing Leadership Institute (GNLI2013) through using differing frequencies of follow-up to assess impact on maintenance of network cohesion. Social network analysis is increasingly been used by nurse researchers, however, studies tend to use single point-in-time descriptive methods. This study utilizes a repeated measures, block group, control-intervention, quasi-experimental design. Twenty-eight nurse leaders, competitively selected through a double-blind peer review process, were allocated to five action learning-based learning groups. Network architecture, measures of cohesion and node degree frequency were all used to assess programme impact. The programme initiated and sustained connections between nurse leaders drawn from a geographically dispersed heterogeneous group. Modest inputs of two to three e-mails over a 6-month period seem sufficient to maintain connectivity as indicated by measures of network density, diameter and path length. Due to the teaching methodology used, the study sample was relatively small and the follow-up data collection took place after a relatively short time. Replication and further cohort data collection would be advantageous. In an era where many policy solutions are being debated and initiated at the global level, action learning leadership development that utilizes new technology follow-up appears to show significant impact and is worthy of wider application. The approach warrants further inquiry and testing as to its longer term effects on nursing's influence on policy formulation and implementation. © 2016 International Council of Nurses.
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Goldman, Anna L; McCormick, Danny; Haas, Jennifer S; Sommers, Benjamin D
2018-04-01
Descriptive studies have suggested that the Affordable Care Act's (ACA's) health insurance Marketplaces improved access to care. However, no evidence from quasi-experimental studies is available to support these findings. We used longitudinal survey data to compare previously uninsured adults with incomes that made them eligible for subsidized Marketplace coverage (138-400 percent of the federal poverty level) to those who had employer-sponsored insurance before the ACA with incomes in the same range. Among the previously uninsured group, the ACA led to a significant decline in the uninsurance rate, decreased barriers to medical care, increased the use of outpatient services and prescription drugs, and increased diagnoses of hypertension, compared to a control group with stable employer-sponsored insurance. Changes were largest among previously uninsured people with incomes of 138-250 percent of poverty, who were eligible for the ACA's cost-sharing reductions. Our quasi-experimental approach provides rigorous new evidence that the ACA's Marketplaces led to improvements in several important health care outcomes, particularly among low-income adults.
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Chen, Su-Hui; Huang, Yu-Ping; Shao, Jung-Hua
2017-09-01
Nutritional health plays a crucial role in determining successful ageing and differs by different living area. Although nutritional interventions have long been advocated, little research has directly assessed the effectiveness of nutritional interventions on community-dwelling older adults in urban and rural areas and compared intervention effects on these two populations. To examine the effectiveness of a 12-week dietary self-management programme for salt-, fluid-, fat- and cholesterol-intake behaviours of community-dwelling older adults and to compare these effects in rural- and urban-dwelling older adults. For this quasi-experimental two-group study, older adults (≥65 years old) were recruited from two randomly selected public health centres in a rural north-eastern county and a northern city of Taiwan from January through December 2011. Outcomes included nutritional status, nutritional self-efficacy and health locus of control. Data were collected at baseline and 12 weeks later. To compare changes in outcome variables over time between the control (usual care) and intervention (nutritional programme) groups and between the urban- and rural-dwelling participants in the experimental group, we used generalised estimating equation analysis. Of the 129 participants, 120 completed this study (58 in the intervention group and 62 in the control group). After 12 weeks, the intervention group had significantly better nutritional status and higher internal health locus of control than the control group. Moreover, older rural participants who received the intervention tended towards higher nutritional self-efficacy and internal health locus of control than their urban counterparts. Our research findings support the positive effect of our nutritional self-management programme for community-dwelling older adults. The knowledge gained from this study can help stakeholders recognise the need for healthcare policy to establish effective strategies and sustainable
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D-Optimal Experimental Design for Contaminant Source Identification
NASA Astrophysics Data System (ADS)
Sai Baba, A. K.; Alexanderian, A.
2016-12-01
Contaminant source identification seeks to estimate the release history of a conservative solute given point concentration measurements at some time after the release. This can be mathematically expressed as an inverse problem, with a linear observation operator or a parameter-to-observation map, which we tackle using a Bayesian approach. Acquisition of experimental data can be laborious and expensive. The goal is to control the experimental parameters - in our case, the sparsity of the sensors, to maximize the information gain subject to some physical or budget constraints. This is known as optimal experimental design (OED). D-optimal experimental design seeks to maximize the expected information gain, and has long been considered the gold standard in the statistics community. Our goal is to develop scalable methods for D-optimal experimental designs involving large-scale PDE constrained problems with high-dimensional parameter fields. A major challenge for the OED, is that a nonlinear optimization algorithm for the D-optimality criterion requires repeated evaluation of objective function and gradient involving the determinant of large and dense matrices - this cost can be prohibitively expensive for applications of interest. We propose novel randomized matrix techniques that bring down the computational costs of the objective function and gradient evaluations by several orders of magnitude compared to the naive approach. The effect of randomized estimators on the accuracy and the convergence of the optimization solver will be discussed. The features and benefits of our new approach will be demonstrated on a challenging model problem from contaminant source identification involving the inference of the initial condition from spatio-temporal observations in a time-dependent advection-diffusion problem.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Xue, Yaosuo
The battery energy stored quasi-Z-source (BES-qZS) based photovoltaic (PV) power generation system combines advantages of the qZS inverter and the battery energy storage system. However, the second harmonic (2 ) power ripple will degrade the system's performance and affect the system's design. An accurate model to analyze the 2 ripple is very important. The existing models did not consider the battery, and with the assumption L1=L2 and C1=C2, which causes the non-optimized design for the impedance parameters of qZS network. This paper proposes a comprehensive model for single-phase BES-qZS-PV inverter system, where the battery is considered and without any restrictionmore » of L1, L2, C1, and C2. A BES-qZS impedance design method based on the built model is proposed to mitigate the 2 ripple. Simulation and experimental results verify the proposed 2 ripple model and design method.« less
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Sun, Chunran; Wang, Muguang; Jian, Shuisheng
2017-08-21
In this paper, a novel quasi-fan Solc structure filter based on elliptical-core spun fiber for twist sensing has been experimentally investigated and theoretically analyzed. The discrete model of spun fiber has been built to analyze the transmission characteristics of proposed sensor. Both experimental and simulated results indicate that the extinction ratio of the comb spectrum based on quasi-fan Solc birefringent fiber filter varies with twist angle and agrees well with each other. Based on the intensity modulation, the proposed twist sensor exhibits a high sensitivity of 0.02219 dB/(°/m). Moreover, thanks to the invariability of the fiber birefringence and the state of polarization of the input light, the proposed twist sensor has a very low temperature and strain sensitivity, which can avoid the cross-sensitivity problem existing in most twist sensors.
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Optimal designs based on the maximum quasi-likelihood estimator
Shen, Gang; Hyun, Seung Won; Wong, Weng Kee
2016-01-01
We use optimal design theory and construct locally optimal designs based on the maximum quasi-likelihood estimator (MqLE), which is derived under less stringent conditions than those required for the MLE method. We show that the proposed locally optimal designs are asymptotically as efficient as those based on the MLE when the error distribution is from an exponential family, and they perform just as well or better than optimal designs based on any other asymptotically linear unbiased estimators such as the least square estimator (LSE). In addition, we show current algorithms for finding optimal designs can be directly used to find optimal designs based on the MqLE. As an illustrative application, we construct a variety of locally optimal designs based on the MqLE for the 4-parameter logistic (4PL) model and study their robustness properties to misspecifications in the model using asymptotic relative efficiency. The results suggest that optimal designs based on the MqLE can be easily generated and they are quite robust to mis-specification in the probability distribution of the responses. PMID:28163359
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Laschober, Tanja C.
2013-01-01
Background On July 24, 2008, New York State (NYS) became the first state to require all state-funded or state-certified substance use disorder (SUD) treatment organizations to be 100% tobacco-free and offer tobacco cessation (TC) treatment. Methods The current study used a quasi-experimental, non-equivalent control group design with a pretest and posttest to examine the effect of the NYS tobacco-free regulation on three clinical practice behaviors (use of TC-related intake procedures, use of guideline recommended counseling for TC, and pharmacotherapy availability) in a diverse sample of SUD treatment programs. Repeated cross-sectional data were collected from NYS counselors (experimental group) and non-NYS counselors (control group) approximately 4 months pre-regulation (N = 282 and 659, respectively) and 10-12 months post-regulation (N = 364 and 733, respectively). Results Using mixed-effects models, results at pre-regulation indicate no group differences in the three clinical practice behaviors. However, significant post-regulation effects were found such that the experimental group reports greater use of TC-related intake procedures, guideline recommended counseling, and availability of pharmacotherapy than the control group. Additionally, the experimental but not the control group shows increases in all three clinical practice behaviors from pre-regulation to post-regulation. Conclusions We conclude that the NYS tobacco-free regulation had a significant and positive effect on promoting patient TC efforts among counselors. PMID:23428317
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Abeid, Muzdalifat; Muganyizi, Projestine; Mpembeni, Rose; Darj, Elisabeth; Axemo, Pia
2016-01-01
Background Sexual violence against women and children in Tanzania and globally is a human rights violation and a developmental challenge. Objective The aim of this study was to assess the impact of training health professionals on rape management. The specific objectives were to evaluate the changes of knowledge and attitudes toward sexual violence among a selected population of health professionals at primary health care level. Design A quasi-experimental design using cross-sectional surveys was conducted to evaluate health care workers’ knowledge, attitude, and clinical practice toward sexual violence before and after the training program. The study involved the Kilombero (intervention) and Ulanga (comparison) districts in Morogoro region. A total of 151 health professionals at baseline (2012) and 169 in the final assessment (2014) participated in the survey. Data were collected using the same structured questionnaire. The amount of change in key indicators from baseline to final assessment in the two areas was compared using composite scores in the pre- and post-interventions, and the net intervention effect was calculated by the difference in difference method. Results Overall, there was improved knowledge in the intervention district from 55% at baseline to 86% and a decreased knowledge from 58.5 to 36.2% in the comparison area with a net effect of 53.7% and a p-value less than 0.0001. The proportion of participants who exhibited an accepting attitude toward violence declined from 15.3 to 11.2% in the intervention area but increased from 13.2 to 20.0% in the comparison area. Conclusions Training on the management of sexual violence is feasible and the results indicate improvement in healthcare workers’ knowledge and practice but not attitudes. Lessons learned from this study for successful replication of such an intervention in similar settings require commitment from those at strategic level within the health service to ensure that adequate resources are
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NASA Astrophysics Data System (ADS)
Chokchai, Jaewijarn; Khanti, Toedtanya; Sura, Wuttiprom
2017-09-01
The purposes of this research were: to construct packages of operations on buoyancy and the involvement of Newton’s third law, to enhance achievement score of students on buoyancy and the involvement of Newton’s third law, to enhance experimental skills on buoyancy and the involvement of Newton’s third law and to evaluate students’ attitude towards the packages of operations on buoyancy and the involvement of Newton’s third law using inquiry method. The samples were 42 grade 11 students in academic year 2016 at Hatyaiwittayalai School, Hatyai, Songkhla. The research method was one group pretest-posttest design. The research tools consisted of experimental set on buoyancy and the involvement of Newton’s third law, the learning achievement test on buoyancy and the involvement of Newton’s third law and the students’ attitude questionnaires. The experimental skills of most students was in a good level . The satisfaction of most students was in a good level. The research showed the learning achievement after instruction higher than that before instruction using experimental set at the significant level of 0.05 and the class average normalized gain is in the medium gain
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Bernstein, Kunsook; Park, So-Young; Hahm, Sohee; Lee, Young Na; Seo, Jin Young; Nokes, Kathleen M.
2016-01-01
Background Asian American women are more prone to suffer with depression compared to their non-Asian American counterparts and have lower rates of seeking mental healthcare services due to lack of available culturally appropriate therapies. Two prior studies of a culturally tailored therapeutic intervention called LogoAutobiography were helpful in treating depressed Korean American women. The LogoAutobiography program was revised to enhance its efficacy not only for depressive symptoms and purpose in life but also to increase coping strategies. Objectives To test the efficacy of the Enhanced LogoAutobiography program on depressive symptoms, purpose in life, and coping strategies of depressed community-dwelling Korean American women. Design Two-group, non-randomized quasi-experimental design. Settings Local Korean community areas located in New York City and eastern New Jersey of the United States. Participants A total of 54 depressed women with Korean heritage completed either experimental group (n1= 25) or control group (n2= 29). Sample inclusion criteria were adult women with Korean heritage, depressive symptoms as measured by a CES-D score 16 or higher, fluent Korean language, and able to participate independently. Sample exclusion criteria were those who presented active suicidal ideation and history of episodes of mania or psychosis screened by the psychosocial survey questionnaire. Methods The experimental group received Enhanced Logo-Autobiography program which was guided by a facilitator who used a manualized intervention for 90 minute sessions over 8 weeks; the control group attended routine weekly community activities. Data were collected during the first session (pretest), the end of 8 weeks (posttest), and the 3 months follow-up session. Time and group changes in depressive symptoms, purpose in life, and coping strategies were computed using Repeated Measures General Linear Model (RMGLM). Results Findings suggested that the experimental group showed
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ERIC Educational Resources Information Center
Yang, Ya-Ting C.; Wu, Wan-Chi I.
2012-01-01
The purpose of this study was to explore the impact of Digital storytelling (DST) on the academic achievement, critical thinking, and learning motivation of senior high school students learning English as a foreign language. The one-year study adopted a pretest and posttest quasi-experimental design involving 110 10th grade students in two English…
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Richmond, Melissa K; Pampel, Fred C; Wood, Randi C; Nunes, Ana P
2016-07-01
To test the impact of Employee Assistance Programs (EAPs) on reducing employee depression, anxiety, and risky alcohol use, and whether improvements in clinical symptoms lead to improved work outcomes. The study used a prospective, quasi-experimental design with propensity score matching. Participants (n = 344) came from 20 areas of state government. EAP (n = 156) and non-EAP (n = 188) employees were matched on baseline demographic, psychosocial, and work-related characteristics that differentiate EAP from non-EAP users. Follow-up surveys were collected 2 to 12 months later (M = 6.0). EAP significantly reduced symptoms of depression and anxiety, but not at-risk alcohol use. EAP reductions in depression and anxiety mediated EAP-based reductions in absenteeism and presenteeism. EAPs provide easy-to-access work-based services that are effective at improving employee mental health.
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Folded Fabry-Perot quasi-optical ring resonator diplexer Theory and experiment
NASA Technical Reports Server (NTRS)
Pickett, H. M.; Chiou, A. E. T.
1983-01-01
Performance of folded Fabry-Perot quasi-optical ring resonator diplexers with different geometries of reflecting surfaces is investigated both theoretically and experimentally. Design of optimum surface geometry for minimum diffraction, together with the figure of merit indicating improvement in performance, are given.
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Porsius, Jarry T; Claassen, Liesbeth; Smid, Tjabe; Woudenberg, Fred; Timmermans, Danielle R M
2014-03-07
New high-voltage power transmission lines will be introduced due to increasing demand for reliable and renewable energy supplies. Some residents associate non-specific health complaints with exposure to electromagnetic fields from nearby power lines. This study protocol describes the design and rationale of a prospective study investigating whether the introduction of a new power line triggers health responses in residents living nearby. The study is designed as a quasi-experimental field study with two pretests during the construction of a new power line route, and two posttests after it has been put into operation. Key outcomes are self-reported non-specific somatic and cognitive health complaints, and attribution of these health complaints to a power line. The main determinant is proximity to the new power line route. One member of every household (n=2379) residing in close proximity (0-500 meters) to the overhead parts of a new power line route in the Netherlands is invited to participate, as well as a sample of household members (n=2382) residing farther away (500-2000 meters). Multilevel analysis will be employed to test whether an increase in key outcome measures is related to proximity to the line. Longitudinal structural equation models will be applied to test to what extent health responses are mediated by psychosocial health mechanisms and moderated by negative oriented personality traits. This is the first study to investigate health responses to a new power line route in a prospective manner. The results will provide theoretical insight into psychosocial mechanisms operating during the introduction of an environmental health risk, and may offer suggestions to policymakers and other stakeholders for minimizing adverse health responses when introducing new high-voltage power lines.
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Yorifuji, Takashi; Kashima, Saori; Doi, Hiroyuki
2016-11-01
Evidence linking air pollution with adverse health outcomes is accumulating. However, few studies have adopted a quasi-experimental design to evaluate whether decline in air pollution from regulatory action improves public health. We evaluated the effect of a diesel emission control ordinance introduced in 2003 on mortality rates in 23 wards of the Tokyo metropolitan area, Japan, from October 2000 to September 2012, taking into account change in mortality rates in a reference population (Osaka) with a introduction of such a regulation in 2009. We obtained daily counts of all-cause and cause-specific mortality and concentrations of nitrogen dioxide (NO2) and particulate matter less than 2.5 μm in diameter (PM2.5) during the study period. We employed interrupted time-series analysis to analyze the data. Decline in NO2 during the study period was similar in the two areas, while decline in PM2.5 and the improvement in age-standardized mortality rates were greater in Tokyo's 23 wards compared with Osaka. Even after adjusting for age-standardized mortality rates in Osaka, percent changes in mortality between the first 3-year interval (October 2000 to September 2003) and the last 3-year interval (October 2009 to September 2012) were -6.0% for all causes, -11% for cardiovascular disease, -10% for ischemic heart disease, -6.2% for cerebrovascular disease, -22% for pulmonary disease, and -4.9% for lung cancer. We did not observe a decline in mortality from other causes. This quasi-experimental study in Tokyo suggests that emission control was associated with improvements in both air quality and health outcomes.
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Go!: results from a quasi-experimental obesity prevention trial with hospital employees.
LaCaille, Lara J; Schultz, Jennifer Feenstra; Goei, Ryan; LaCaille, Rick A; Dauner, Kim Nichols; de Souza, Rebecca; Nowak, Amy Versnik; Regal, Ronald
2016-02-19
Worksite obesity prevention interventions using an ecological approach may hold promise for reducing typical weight gain. The purpose of this study was to examine the effectiveness of Go!, an innovative 12-month multi-component worksite obesity prevention intervention. A quasi-experimental non-equivalent control group design was utilized; 407 eligible hospital employees (intervention arm) and 93 eligible clinic employees (comparison arm) participated. The intervention involved pedometer distribution, labeling of all foods in the worksite cafeteria and vending machines (with calories, step equivalent, and a traffic light based on energy density signaling recommended portion), persuasive messaging throughout the hospital, and the integration of influential employees to reinforce healthy social norms. Changes in weight, BMI, waist circumference, physical activity, and dietary behavior after 6 months and 1 year were primary outcomes. Secondary outcomes included knowledge, perceptions of employer commitment to employee health, availability of information about diet, exercise, and weight loss, perceptions of coworker support and frequency of health discussions with coworkers. A process evaluation was conducted as part of the study. Repeated measures ANCOVA indicated that neither group showed significant increases in weight, BMI, or waist circumference over 12 months. The intervention group showed a modest increase in physical activity in the form of walking, but decreases in fruit and vegetable servings and fiber intake. They also reported significant increases in knowledge, information, perceptions of employer commitment, and health discussions with peers. Employees expressed positive attitudes towards all components of the Go! This low-intensity intervention was well-received by employees but had little effect on their weight over the course of 12 months. Such results are consistent with other worksite obesity prevention studies using ecological approaches
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ERIC Educational Resources Information Center
Markette, Jo Ann Alicia Foley
2012-01-01
The purpose of this study was to examine whether or not a change in religiosity would occur in undergraduate students at a West Coast Christian university as a result of their participation in an online Christian worldview course. Twenty-six undergraduate students participated in this pretest posttest quasi-experimental study which employed the…
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NASA Astrophysics Data System (ADS)
Moin, Laura
2009-10-01
The American Recovery and Reinvestment Act national policy established in 2009 calls for ``meaningful data'' that demonstrate educational improvements, including the recruitment of high-quality teachers. The scant data available and the low credibility of many K-12 math/science teacher recruitment program evaluations remain the major barriers for the identification of effective recruitment strategies. Our study presents a methodology to better evaluate the impact of recruitment programs on increasing participants' interest in teaching careers. The research capitalizes on the use of several control groups and presents a non-equivalent groups quasi-experimental evaluation design that produces program effect claims with higher internal validity than claims generated by current program evaluations. With this method that compares responses to a teaching career interest question from undergraduates all along a continuum from just attending an information session to participating (or not) in the recruitment program, we were able to compare the effect of the program in increasing participants' interest in teaching careers versus the evolution of the same interest but in the absence of the program. We were also able to make suggestions for program improvement and further research. While our findings may not apply to other K-12 math/science teacher recruitment programs, we believe that our evaluation methodology does and will contribute to conduct stronger program evaluations. In so doing, our evaluation procedure may inform recruitment program designers and policy makers.
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Wu, Shu-Fang Vivienne; Liang, Shu-Yuan; Lee, Mei-Chen; Yu, Neng-Chun; Kao, Mu-Jung
2014-09-01
To analyse the efficacy of improving disease management after implementing a self-management programme for people with type 2 diabetes administered by healthcare workers who have received special training. The needs for diabetic care include increased training for healthcare providers to enhance their confidence and skills in managing patients, both physically and mentally. Quasi-experimental design. This study recruited participants from outpatient clinics in 10 hospitals in Taiwan. In 2010, purposive sampling was used to recruit 228 participants from two medical centres, five regional hospitals and three district hospitals. Participants were enrolled in a 'diabetes self-management programme' (watching patient videos, reading a diabetes self-care handbook, participating in four consultation courses of diabetes self-efficacy improvement, telephone follow-up and positive reinforcement). Efficacy analysis of post-test diabetes outcome variables of the experimental group was carried out. Sex, age and pretest score were used as the control variables for ancova test. Patients in the experimental group had significant improvement in body mass index (p < 0·01), waistline circumference (p < 0·001), haemoglobin A1C levels (p < 0·001), degrees of anxiety and depression (p < 0·001), self-efficacy (p < 0·001) and levels of self-care (p < 0·001). Self-efficacy of people with diabetes can be effectively improved by planned implementation of a 'diabetes self-management programme' by trained healthcare workers. The diabetes care professionals are provided the self-management programme to strengthen the awareness and importance of self-management in diabetes care. © 2013 John Wiley & Sons Ltd.
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Hains, Guy; Boucher, Pierre B; Lamy, Anne-Marie
2015-03-01
The aim of this study was to evaluate the efficacy of myofascial therapy involving ischemic compression on trigger points in combination with mobilization therapy on patients with chronic nonspecific foot pain. Two quasi-experimental before-and-after studies involving two different baseline states. Foot pain patients at a private clinic were divided into two separate cohorts: A, custom orthotic users; and B, non-users. In Study A, 31 users received 15 experimental treatments consisting of ischemic compressions on trigger points and mobilization of articulations through the foot immediately after study enrollment. In study B, ten non-users were prescribed a soft prefabricated insole and were monitored for five weeks before subsequently receiving 15 experimental treatments after the initial five-week delay. The Foot Function Index (FFI) and patients' perceived improvement score (PIS) on a scale from 0% to 100%. The Study A group (n=31) maintained a significant reduction in the FFI at all three follow-up evaluations. Mean improvement from baseline in FFI was 47%, 49% and 56% at 0, 1 and 6 months, respectively, post-treatment. Mean PIS was 58%, 57%, and 58%, again at 0, 1 and 6 months post-treatment. For the Study B group, mean improvement in FFI was only 19% after the monitoring period, and 64% after the experimental treatment period. Mean PIS was 31% after monitoring, and 78% after experimental treatment. In repeated measures analyses, experimental treatment was associated with a significant main effect in both of these before-and after studies (all P values<0.01). Combined treatment involving ischemic compression and joint mobilization for chronic foot pain is associated with significant improvements in functional and self-perceived improvement immediately and at up to six-months post-treatment. Further validation of this treatment approach within a randomized controlled trial is needed.
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The quasi-equilibrium response of MOS structures: Quasi-static factor
NASA Astrophysics Data System (ADS)
Okeke, M.; Balland, B.
1984-07-01
The dynamic response of a MOS structure driven into a non-equilibrium behaviour by a voltage ramp is presented. In contrast to Khun's quasi-static technique it is shown that any ramp-driven MOS structure has some degree of non-equilibrium. A quasi staticity factor μAK which serves as a measure of the degree of quasi-equilibrium, has been introduced for the first time. The mathematical model presented in the paper allows a better explanation of the experimental recordings. It is shown that this model could be used to analyse the various features of the response of the structure and that such physical parameters as the generation-rate, trap activation energy, and the effective capture constants could be obtained.
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Eby, Lillian T; Laschober, Tanja C
2013-09-01
On July 24, 2008, New York State (NYS) became the first state to require all state-funded or state-certified substance use disorder (SUD) treatment organizations to be 100% tobacco-free and offer tobacco cessation (TC) treatment. The current study used a quasi-experimental, non-equivalent control group design with a pretest and posttest to examine the effect of the NYS tobacco-free regulation on three clinical practice behaviors (use of TC-related intake procedures, use of guideline recommended counseling for TC, and pharmacotherapy availability) in a diverse sample of SUD treatment programs. Repeated cross-sectional data were collected from NYS counselors (experimental group) and non-NYS counselors (control group) approximately 4 months pre-regulation (N=282 and 659, respectively) and 10-12 months post-regulation (N=364 and 733, respectively). Using mixed-effects models, results at pre-regulation indicate no group differences in the three clinical practice behaviors. However, significant post-regulation effects were found such that the experimental group reports greater use of TC-related intake procedures, guideline recommended counseling, and availability of pharmacotherapy than the control group. Additionally, the experimental but not the control group shows increases in all three clinical practice behaviors from pre-regulation to post-regulation. We conclude that the NYS tobacco-free regulation had a significant and positive effect on promoting patient TC efforts among counselors. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.
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Richmond, Sarah A; Rothman, Linda; Buliung, Ron; Schwartz, Naomi; Larsen, Kristian; Howard, Andrew
2014-10-01
The frequency of pedestrian collisions is strongly influenced by the built environment, including road width, street connectivity and public transit design. In 2010, 2159 pedestrian collisions were reported in the City of Toronto, Canada with 20 fatalities. Previous studies have reported that streetcars operating in mixed traffic pose safety risks to pedestrians; however, few studies evaluate the effects on pedestrian-motor vehicle collisions (PMVC). The objective of this study was to examine changes in the rate and spatial patterning of PMVC, pre to post right-of-way (ROW) installation of the St. Clair Avenue West streetcar in the City of Toronto, Canada. A quasi-experimental design was used to evaluate changes in PMVC rate, following implementation of a streetcar ROW. Collision data were extracted from all police-reported PMVC, complied and verified by the City of Toronto, from January 1, 2000 to December 31, 2011. A zero-inflated Poisson regression analysis estimated the change in PMVC, pre to post ROW. Age and injury severity were also examined. Changes in the spatial pattern of collisions were examined by applying the G function to describe the proportion of collision events that shared a nearest neighbor distance less than or equal to a threshold distance. A total of 23,607 PMVC occurred on roadways during the study period; 441 occurring on St. Clair Ave, 153 during the period of analysis. There was a 48% decrease in the rate of collisions on St. Clair [Incidence rate ratio (IRR)=0.52, 95% CI: 0.37-0.74], post ROW installation. There were also decreases noted for children (IRR=0.13, 95% CI: 0.04-0.44), adults (IRR=0.61, 95% CI: 0.38-0.97), and minor injuries (IRR=0.56, 95% CI: 0.40-0.80). Spatial analyses indicated increased dispersion of collision events across each redeveloped route segment following the changes in ROW design. Construction of a raised ROW operating on St. Clair Ave. was associated with a reduction in the rate of collisions. Differences in
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Abeid, Muzdalifat; Muganyizi, Projestine; Mpembeni, Rose; Darj, Elisabeth; Axemo, Pia
2016-01-01
Sexual violence against women and children in Tanzania and globally is a human rights violation and a developmental challenge. The aim of this study was to assess the impact of training health professionals on rape management. The specific objectives were to evaluate the changes of knowledge and attitudes toward sexual violence among a selected population of health professionals at primary health care level. A quasi-experimental design using cross-sectional surveys was conducted to evaluate health care workers' knowledge, attitude, and clinical practice toward sexual violence before and after the training program. The study involved the Kilombero (intervention) and Ulanga (comparison) districts in Morogoro region. A total of 151 health professionals at baseline (2012) and 169 in the final assessment (2014) participated in the survey. Data were collected using the same structured questionnaire. The amount of change in key indicators from baseline to final assessment in the two areas was compared using composite scores in the pre- and post-interventions, and the net intervention effect was calculated by the difference in difference method. Overall, there was improved knowledge in the intervention district from 55% at baseline to 86% and a decreased knowledge from 58.5 to 36.2% in the comparison area with a net effect of 53.7% and a p-value less than 0.0001. The proportion of participants who exhibited an accepting attitude toward violence declined from 15.3 to 11.2% in the intervention area but increased from 13.2 to 20.0% in the comparison area. Training on the management of sexual violence is feasible and the results indicate improvement in healthcare workers' knowledge and practice but not attitudes. Lessons learned from this study for successful replication of such an intervention in similar settings require commitment from those at strategic level within the health service to ensure that adequate resources are made available.
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Bi-Frequency Modulated Quasi-Resonant Converters: Theory and Applications
NASA Astrophysics Data System (ADS)
Zhang, Yuefeng
1995-01-01
To avoid the variable frequency operation of quasi -resonant converters, many soft-switching PWM converters have been proposed, all of them require an auxiliary switch, which will increase the cost and complexity of the power supply system. In this thesis, a new kind of technique for quasi -resonant converters has been proposed, which is called the bi-frequency modulation technique. By operating the quasi-resonant converters at two switching frequencies, this technique enables quasi-resonant converters to achieve the soft-switching, at fixed switching frequencies, without an auxiliary switch. The steady-state analysis of four commonly used quasi-resonant converters, namely, ZVS buck, ZCS buck, ZVS boost, and ZCS boost converter has been presented. Using the concepts of equivalent sources, equivalent sinks, and resonant tank, the large signal models of these four quasi -resonant converters were developed. Based on these models, the steady-state control characteristics of BFM ZVS buck, BFM ZCS buck, BFM ZVS boost, and BFM ZCS boost converter have been derived. The functional block and design consideration of the bi-frequency controller were presented, and one of the implementations of the bi-frequency controller was given. A complete design example has been presented. Both computer simulations and experimental results have verified that the bi-frequency modulated quasi-resonant converters can achieve soft-switching, at fixed switching frequencies, without an auxiliary switch. One of the application of bi-frequency modulation technique is for EMI reduction. The basic principle of using BFM technique for EMI reduction was introduced. Based on the spectral analysis, the EMI performances of the PWM, variable-frequency, and bi-frequency modulated control signals was evaluated, and the BFM control signals show the lowest EMI emission. The bi-frequency modulated technique has also been applied to the power factor correction. A BFM zero -current switching boost converter has
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Laguerre-Gaussian quasi-modal q-plates from nanostructured glasses
NASA Astrophysics Data System (ADS)
Rafayelyan, Mushegh; Gertus, Titas; Brasselet, Etienne
2017-06-01
A quasi-modal version of the recently introduced Laguerre-Gaussian modal q-plates [Rafayelyan and Brasselet, Opt. Lett. 42, 1966-1969 (2017)] is proposed and implemented using femtosecond direct laser writing of space-variant nanogratings in the bulk of silica glass. The corresponding design consists of linear azimuthal modulation of the optical axis orientation and polynomial radial modulation of the retardance profile. Experimental demonstration is made for Laguerre-Gaussian modes with azimuthal indices l =(1, 2, 3) and radial index p = 0. Such quasi-modal q-plates overcome previous limitations regarding the robustness of modality against the handedness of the incident circular polarization state.
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ERIC Educational Resources Information Center
Tourigny, Andre; Durand, Pierre J.; Bonin, Lucie; Hebert, Rejean; Rochette, Louis
2004-01-01
The aim of this study was to examine the effectiveness of a new, integrated service delivery (ISD) network of health and social services for frail elderly living in a semi-urban community. A quasi-experimental study was conducted from 1997 to 2000, with measures taken before implementation (T0) and every 12 months after implementation for a 3-year…
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A Short-Term, Quasi-Experimental Evaluation of D.A.R.E.'s Revised Elementary School Curriculum
ERIC Educational Resources Information Center
Vincus, Amy A.; Ringwalt, Chris; Harris, Melissa S.; Shamblen, Stephen R.
2010-01-01
We present the short-term results of a quasi-experimental evaluation of the revised D. A. R. E. (Drug Abuse Resistance Education) curriculum. Study outcomes examined were D. A. R. E.'s effects on three substances, namely students' lifetime and 30-day use of tobacco, alcohol, and marijuana, as well as their school attendance and academic…
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NASA Astrophysics Data System (ADS)
Wong, Chi Ho
In this PhD project, the feasibility of establishing a state with vanishing resistance in quasi-1D superconductors are studied. In the first stage, extrinsic quasi-1D superconductors based on composite materials made by metallic nanowire arrays embedded in mesoporous silica substrates, such as Pb-SBA-15 and NbN-SBA-15 (fabricated by a Chemical Vapor Deposition technique) are investigated. Two impressive outcomes in Pb-SBA-15 are found, including an enormous enhancement of the upper critical field from 0.08T to 14T and an increase of the superconducting transition temperature onset s from 7.2 to 11K. The second stage is to apply Monte Carlo simulations to model the quasi-1D superconductor, considering its penetration depth, coherence length, defects, electron mean free path, tunneling barrier and insulating width between the nanowires. The Monte Carlo results provide a clear picture to approach to stage 3, which represents a study of the intrinsic quasi-1D superconductor Sc3CoC4, which contains parallel arrays of 1D superconducting CoC4 ribbons with weak transverse Josephson or Proximity interaction, embedded in a Sc matrix. According to our previous work, a BKT transition in the lateral plane is believed to be the physics behind the vanishing resistance of quasi-1D superconductors, because it activates a dimensional crossover from a 1D fluctuating superconductivity at high temperature to a 3D bulk phase coherent state in the entire material at low temperatures. Moreover, we decided to study thin 1D Sn nanowires without substrate, which display very similar superconducting properties to Pb-SBA-15 with a strong critical field and Tc enhancement. Finally, a preliminary research on a novel quasi-2D superconductor formed by parallel 2D mercury sheets that are separated by organic molecules is presented. The latter material may represent a model system to study the effect of a layered structure, which is believed to be an effective ingredient to design high temperature
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Gisladottir, M; Svavarsdottir, E K
2017-02-01
WHAT IS KNOWN ON THE SUBJECT?: Caregivers of adolescents with ADHD experience major difficulties as care providers and are in need of guidance and support. Adolescents with ADHD may develop oppositional and criminal behaviour. More than 50 % have the symptoms in adulthood, and up to one-fourth with severe emotional or antisocial difficulties. There is a lack of evidence of caregivers' supporting intervention although caregiver groups have been found to contribute to better coping, decreased stress and improvements in ADHD symptoms. WHAT DOES THIS PAPER ADD TO EXISTING KNOWLEDGE?: Primary caregivers of adolescents with ADHD experienced better quality of life after the Therapeutic Conversation Intervention. The intervention contributed to better social functioning among secondary caregivers. WHAT ARE THE IMPLICATIONS FOR PRACTICE?: The content of the Therapeutic Conversation Intervention is significant and highlights the utility of a combination of group and private sessions for caregivers of people with ADHD. The intervention can influence how services for families are organized, such that a Therapeutic Conversation Intervention could be offered on a regular basis. Introduction Caregivers of adolescents with Attention Deficit Hyperactivity Disorder are burdened with tasks and many suffer from distress. Adolescents with ADHD may develop antisocial behaviour and caregiver's group can empower caregiver's supporting role. Aim/Question To evaluate the effectiveness of a Therapeutic Conversation Intervention on caregivers of adolescents with ADHD regarding strengthening the supportive role. Method The study utilized a quasi-experimental design. The participants (n = 60) were caregivers of adolescents (13-17 years old) with ADHD. The intervention consisted in-group and parent sessions. The Calgary Family Model and the Family Illness Beliefs Model were used as theoretical frameworks. Results The study revealed significant differences in the improvement of quality of life
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Talbot effect of quasi-periodic grating.
Zhang, Chong; Zhang, Wei; Li, Furui; Wang, Junhong; Teng, Shuyun
2013-07-20
Theoretic and experimental studies of the Talbot effect of quasi-periodic gratings are performed in this paper. The diffractions of periodic and quasi-periodic square aperture arrays in Fresnel fields are analyzed according to the scalar diffraction theory. The expressions of the diffraction intensities of two types of quasi-periodic gratings are deduced. Talbot images of the quasi-periodic gratings are predicted to appear at multiple certain distances. The quasi-periodic square aperture arrays are produced with the aid of a liquid crystal light modulator, and the self-images of the quasi-periodic gratings are measured successfully in the experiment. This study indicates that even a structure in short-range disorder may take on the self-imaging effect in a Fresnel field.
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Quasi-optical antenna-mixer-array design for terahertz frequencies
NASA Technical Reports Server (NTRS)
Guo, Yong; Potter, Kent A.; Rutledge, David B.
1992-01-01
A new quasi-optical antenna-mixer-array design for terahertz frequencies is presented. In the design, antenna and mixer are combined into an entity, based on the technology in which millimeter-wave horn antenna arrays have been fabricated in silicon wafers. It consists of a set of forward- and backward-looking horns made with a set of silicon wafers. The front side is used to receive incoming signal, and the back side is used to feed local oscillator signal. Intermediate frequency is led out from the side of the array. Signal received by the horn array is picked up by antenna probes suspended on thin silicon-oxynitride membranes inside the horns. Mixer diodes will be located on the membranes inside the horns. Modeling of such an antenna-mixer-array design is done on a scaled model at microwave frequencies. The impedance matching, RF and LO isolation, and patterns of the array have been tested and analyzed.
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ERIC Educational Resources Information Center
Smith, Kasee L.; Rayfield, John
2017-01-01
Understanding methods for effectively instructing STEM education concepts is essential in the current climate of education (Freeman, Marginson, & Tyler 2014). Kolb's experiential learning theory (ELT) outlines four specific modes of learning, based on preferences for grasping and transforming information. This quasi-experimental study was…
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Do cooperative learning and family involvement improve variables linked to academic performance?
Santos Rego, Miguel A; Ferraces Otero, María J; Godas Otero, Agustín; Lorenzo Moledo, María M
2018-05-01
One of the most serious problems in the Spanish education system is the high percentage of school failure in Compulsory Secondary Education. The aim of this study is to analyze the influence of a socio-educational program based on cooperative learning and family involvement on a series of variables related to academic performance, paying particular attention to the differences between retained and non-retained students. A two-group quasi-experimental design incorporating pre-testing and post-testing was used. The study involved 146 students in the experimental group and 123 in the control group, 8 teachers, and 89 parents or other family members. The program was observed to have a positive effect on self-image, study habits, satisfaction with the subject, maternal support and control, and opinions about the school. In addition, the results for non-retained students are better. Cooperative work and family involvement in education affect the variables which research links to improving school performance.
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ERIC Educational Resources Information Center
Muller, Eugene W.
1985-01-01
Develops generalizations for empirical evaluation of software based upon suitability of several research designs--pretest posttest control group, single-group pretest posttest, nonequivalent control group, time series, and regression discontinuity--to type of software being evaluated, and on circumstances under which evaluation is conducted. (MBR)
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Dambi, Jermaine M; Jelsma, Jennifer
2014-12-05
Cerebral palsy requires appropriate on-going rehabilitation intervention which should effectively meet the needs of both children and parents/care-givers. The provision of effective support is a challenge, particularly in resource constrained settings. A quasi-experimental pragmatic research design was used to compare the impact of two models of rehabilitation service delivery currently offered in Harare, Zimbabwe, an outreach-based programme and the other institution-based. Questionnaires were distributed to 46 caregivers of children with cerebral palsy at baseline and after three months. Twenty children received rehabilitation services in a community setting and 26 received services as outpatients at a central hospital. The Gross Motor Function Measurement was used to assess functional change. The burden of care was measured using the Caregiver Strain Index, satisfaction with physiotherapy was assessed using the modified Medrisk satisfaction with physiotherapy services questionnaire and compliance was measured as the proportion met of the scheduled appointments. Children receiving outreach-based treatment were significantly older than children in the institution-based group. Regression analysis revealed that, once age and level of severity were controlled for, children in the outreach-based treatment group improved their motor function 6% more than children receiving institution-based services. There were no differences detected between the groups with regard to caregiver well-being and 51% of the caregivers reported signs consistent with clinical distress/depression. Most caregivers (83%) expressed that they were overwhelmed by the caregiving role and this increased with the chronicity of care. The financial burden of caregiver was predictive of caregiver strain. Caregivers in the outreach-based group reported greater satisfaction with services and were more compliant (p < .001) as compared to recipients of institution-based services. Long term caregiving
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Yang, Chiu-Yueh; Lee, Tien-Hao; Lo, Su-Chen; Beckstead, Jason W
2015-12-01
To examine the effectiveness of an auditory hallucinatory symptom management programme in patients with chronic schizophrenia. Thirty per cent of chronic schizophrenia patients are still disturbed by hallucinations, which influence their psychological and social well-being, even when they take medication regularly. Fifty-eight people experiencing schizophrenia with auditory hallucinations from psychiatric inpatient rehabilitation wards in northern Taiwan participated in the study, with 29 in the experimental group and 29 in the control group. The experimental group received an auditory hallucinatory symptom management programme. The auditory hallucinatory symptom management programme involved 60-minute meetings once a week, for a total of 10 meetings. The control group received routine care, which included free recreation for 40 minutes and walking for 20 minutes. The participants completed three self-report questionnaires: the Beck Depressive Inventory II, the Beck Anxiety Inventory and the Characteristics of Auditory Hallucinations Questionnaire. Data were collected at baseline, immediately following the intervention and at 3 months and 6 months post intervention. Data collection occurred between March 2010-May 2013. The experimental group showed a non-significant improvement in anxiety symptoms over time. Generalized estimating equations revealed that the experimental group achieved a greater drop in Characteristics of Auditory Hallucinations Questionnaire score than the controls at three and 6 months post intervention. Beck Depressive Inventory II scores in the experimental group (n = 29) had significantly improved in 3 months. The auditory hallucinatory symptom management programme seems to be effective in improving auditory hallucinatory symptoms and depressive symptoms in patients with schizophrenia. © 2015 John Wiley & Sons Ltd.
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Screening Mammography & Breast Cancer Mortality: Meta-Analysis of Quasi-Experimental Studies
Irvin, Veronica L.; Kaplan, Robert M.
2014-01-01
Background The magnitude of the benefit associated with screening has been debated. We present a meta-analysis of quasi-experimental studies on the effects of mammography screening. Methods We searched MEDLINE/PubMed and Embase for articles published through January 31, 2013. Studies were included if they reported: 1) a population-wide breast cancer screening program using mammography with 5+ years of data post-implementation; 2) a comparison group with equal access to therapies; and 3) breast cancer mortality. Studies excluded were: RCTs, case-control, or simulation studies. We defined quasi-experimental as studies that compared either geographical, historical or birth cohorts with a screening program to an equivalent cohort without a screening program. Meta-analyses were conducted in Stata using the metan command, random effects. Meta-analyses were conducted separately for ages screened: under 50, 50 to 69 and over 70 and weighted by population and person-years. Results Among 4,903 published papers that were retrieved, 19 studies matched eligibility criteria. Birth cohort studies reported a significant benefit for women screened
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Promoting walking to school: results of a quasi-experimental trial.
McKee, Rosie; Mutrie, Nanette; Crawford, Fiona; Green, Brian
2007-09-01
To assess the impact of a combined intervention on children's travel behaviour, stage of behavioural change and motivations for and barriers to actively commuting to school. A quasi-experimental trial involving pre- and post-intervention mapping of routes to school by active and inactive mode of travel and surveys of "stage of behaviour change" and motivations for and barriers to actively commuting to school. The intervention school participated in a school-based active travel project for one school term. Active travel was integrated into the curriculum and participants used interactive travel-planning resources at home. The control school participated in before and after measurements but did not receive the intervention. Two primary schools in Scotland with similar socioeconomic and demographic profiles. Two classes of primary 5 children and their families and teachers. Post intervention, the mean distance travelled to school by walking by intervention children increased significantly from baseline, from 198 to 772 m (389% increase). In the control group mean distance walked increased from 242 to 285 m (17% increase). The difference between the schools was significant (t (38) = -4.679, p<0.001 (95% confidence interval -315 to -795 m)). Post intervention, the mean distance travelled to school by car by intervention children reduced significantly from baseline, from 2018 to 933 m (57.5% reduction). The mean distance travelled to school by car by control children increased from baseline, from 933 to 947 m (1.5% increase). The difference in the change between schools was significant (t (32) = 4.282, p<0.001 (95% confidence interval 445 to 1255 m)). Intervention was effective in achieving an increase in the mean distance travelled by active mode and a reduction in the mean distance travelled by inactive mode on school journey.
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Liang, Weihua; Liu, Yushan; Ge, Baoming; ...
2017-09-08
The battery energy stored quasi-Z-source (BESqZS) based photovoltaic (PV) power generation system combines advantages of the qZS inverter and the battery energy storage system. But, the second harmonic (2ω) power ripple degrades the system’s performance and affects the system’s design. An accurate model to analyze the 2ω ripple is very important. The existing models did not consider the battery, or assumed a symmetric qZS network with L 1=L 2 and C 1=C 2, which limits the design freedom and causes oversized impedance parameters. Our paper proposes a comprehensive model for the single-phase BES-qZS-PV inverter system, where the battery is consideredmore » and there is no restriction of L 1=L 2 and C 1=C 2. Based on the built model, a BES-qZS impedance design method is proposed to mitigate the 2ω ripple with asymmetric qZS network. Simulation and experimental results verify the proposed 2ω ripple model and impedance design method.« less
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Liang, Weihua; Liu, Yushan; Ge, Baoming
The battery energy stored quasi-Z-source (BESqZS) based photovoltaic (PV) power generation system combines advantages of the qZS inverter and the battery energy storage system. But, the second harmonic (2ω) power ripple degrades the system’s performance and affects the system’s design. An accurate model to analyze the 2ω ripple is very important. The existing models did not consider the battery, or assumed a symmetric qZS network with L 1=L 2 and C 1=C 2, which limits the design freedom and causes oversized impedance parameters. Our paper proposes a comprehensive model for the single-phase BES-qZS-PV inverter system, where the battery is consideredmore » and there is no restriction of L 1=L 2 and C 1=C 2. Based on the built model, a BES-qZS impedance design method is proposed to mitigate the 2ω ripple with asymmetric qZS network. Simulation and experimental results verify the proposed 2ω ripple model and impedance design method.« less
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ERIC Educational Resources Information Center
Bordoloi Pazich, Loni
2014-01-01
This study uses statewide longitudinal data from Texas to estimate the impact of a state grant program intended to encourage low-income community college students to transfer to four-year institutions and complete the baccalaureate. Quasi-experimental methods employed include propensity score matching and regression discontinuity. Results indicate…
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ERIC Educational Resources Information Center
Leap, Evelyn M.
2013-01-01
This quasi-experimental study was conducted with two fifth grade classrooms to investigate the effect of scent on students' acquisition and retention of multiplication facts and math anxiety. Forty participants received daily instruction for nine weeks, using a strategy-rich multiplication program called Factivation. Students in the Double Smencil…
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Socia, Kelly M
2015-04-01
This study examines whether the presence of state residence restrictions resulted in changes in statewide rates of forcible rape. It builds on the limited geographic coverage of prior studies by including state-level Uniform Crime Report (UCR) data across 19 years for 49 states and the District of Columbia. It uses a quasi-experimental research method based on a longitudinal fixed-effects panel model design, which can help control for relatively static differences between states. Results indicate that when a state residence restriction was present, regardless of how it was measured, rates of UCR forcible rape were higher in the state than when the policy was not present. This suggests that residence restrictions, at least at the state level, are not useful as an overall crime prevention measure, but may be useful for increasing detection or reporting levels of such crimes. However, results also suggest that the size of the increase varied by whether the policy only applied to offenders with child victims or also included those with adult victims. Implications for research and policy are discussed. © The Author(s) 2013.
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Quasi-experimental evaluation of a national primary school HIV intervention in Kenya.
Maticka-Tyndale, Eleanor; Wildish, Janet; Gichuru, Mary
2007-05-01
This study examined the impact of a primary-school HIV education initiative on the knowledge, self-efficacy and sexual and condom use activities of upper primary-school pupils in Kenya. A quasi-experimental mixed qualitative-quantitative pre- and 18-month post-design using 40 intervention and 40 matched control schools demonstrated significant program impact on targeted objectives of (1) adequate program delivery and, for standard 6 and 7 pupils (ages 11-16 years), (2) increased HIV-related knowledge; (3) increased communication with parents and teachers about HIV and sexuality; (4) increased assistance to fellow pupils to avoid sexual activity; (5) increased self-efficacy related to abstinence and condom use; (6) decreased exposure to HIV through delayed first intercourse, decreased sexual activity and increased condom. Results support the conclusions that the existing infrastructure is adequate for national roll-out of the program; that the program has its most beneficial effect on sexually inexperienced youth and should therefore be implemented with the youngest age groups possible; and that gains are gender specific, with boys reporting increased condom use while girls are more likely to decrease or delay sexual activity. Based on these results, the program began national roll-out to all primary schools in 2005. By June 2006, the program was operating in 11,000 of the country's nearly 19,000 schools.
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Skerfving, Annemi; Johansson, Fredrik; Elgán, Tobias H
2014-01-24
Support groups for children in troubled families are available in a majority of Swedish municipalities. They are used as a preventive effort for children in families with different parental problems such as addiction to alcohol/other drugs, mental illness, domestic violence, divorce situations, or even imprisonment. Children from families with these problems are a well-known at-risk group for various mental health and social problems. Support groups aim at strengthening children's coping behaviour, to improve their mental health and to prevent a negative psycho-social development. To date, evaluations using a control-group study design are scarce. The aim of the current study is to evaluate the effects of support groups. This paper describes the design of an effectiveness study, initially intended as a randomized controlled trial, but instead is pursued as a quasi-experimental study using a non-randomized control group. The aim is to include 116 children, aged 7-13 years and one parent/another closely related adult, in the study. Participants are recruited via existing support groups in the Stockholm county district and are allocated either into an intervention group or a waiting list control group, representing care as usual. The assessment consists of questionnaires that are to be filled in at baseline and at four months following the baseline. Additionally, the intervention group completes a 12-month follow-up. The outcomes include the Strength and Difficulties Questionnaire (SDQ S11-16), the Kids Coping Scale, the "Ladder of life" which measures overall life satisfaction, and "Jag tycker jag är" (I think I am) which measures self-perception and self-esteem. The parents complete the SDQ P4-16 (parent-report version) and the Swedish scale "Familjeklimat" (Family Climate), which measures the emotional climate in the family. There is a need for evaluating the effects of support groups targeted to children from troubled families. This quasi-experimental study
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NASA Astrophysics Data System (ADS)
Zhang, Jiu-Chang
2018-02-01
Triaxial compression tests are conducted on a quasi-brittle rock, limestone. The analyses show that elastoplastic deformation is coupled with damage. Based on the experimental investigation, a coupled elastoplastic damage model is developed within the framework of irreversible thermodynamics. The coupling effects between the plastic and damage dissipations are described by introducing an isotropic damage variable into the elastic stiffness and yield criterion. The novelty of the model is in the description of the thermodynamic force associated with damage, which is formulated as a state function of both elastic and plastic strain energies. The latter gives a full consideration on the comprehensive effects of plastic strain and stress changing processes in rock material on the development of damage. The damage criterion and potential are constructed to determine the onset and evolution of damage variable. The return mapping algorithms of the coupled model are deduced for three different inelastic corrections. Comparisons between test data and numerical simulations show that the coupled elastoplastic damage model is capable of describing the main mechanical behaviours of the quasi-brittle rock.
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ERIC Educational Resources Information Center
Negley, Sandra Anne
The main purpose of this study was to determine and describe the effects of the comprehension component of the criterion-referenced reading program, Wisconsin Design for Reading Skills Development (WDRSD), on reading achievement and self-concept of sixth-grade students. Parametric techniques were employed in a quasi-experimental study involving 44…
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ERIC Educational Resources Information Center
Maruska, K.; Morgenstern, M.; Isensee, B.; Hanewinkel, R.
2010-01-01
Effects of the life skills programme "Eigenstandig werden" (Becoming independent) on life skills and on identified antecedents of adolescent health risk behaviour, childhood internalizing and externalizing behaviour were tested in an elementary school setting. A quasi-experimental controlled trial with five repeated measures was…
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Bor, Jacob; Geldsetzer, Pascal; Venkataramani, Atheendar; Bärnighausen, Till
2015-01-01
Purpose of review Randomized, population-representative trials of clinical interventions are rare. Quasi-experiments have been used successfully to generate causal evidence on the cascade of HIV care in a broad range of real-world settings. Recent findings Quasi-experiments exploit exogenous, or quasi-random, variation occurring naturally in the world or because of an administrative rule or policy change to estimate causal effects. Well designed quasi-experiments have greater internal validity than typical observational research designs. At the same time, quasi-experiments may also have potential for greater external validity than experiments and can be implemented when randomized clinical trials are infeasible or unethical. Quasi-experimental studies have established the causal effects of HIV testing and initiation of antiretroviral therapy on health, economic outcomes and sexual behaviors, as well as indirect effects on other community members. Recent quasi-experiments have evaluated specific interventions to improve patient performance in the cascade of care, providing causal evidence to optimize clinical management of HIV. Summary Quasi-experiments have generated important data on the real-world impacts of HIV testing and treatment and on interventions to improve the cascade of care. With the growth in large-scale clinical and administrative data, quasi-experiments enable rigorous evaluation of policies implemented in real-world settings. PMID:26371463
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Bor, Jacob; Geldsetzer, Pascal; Venkataramani, Atheendar; Bärnighausen, Till
2015-11-01
Randomized, population-representative trials of clinical interventions are rare. Quasi-experiments have been used successfully to generate causal evidence on the cascade of HIV care in a broad range of real-world settings. Quasi-experiments exploit exogenous, or quasi-random, variation occurring naturally in the world or because of an administrative rule or policy change to estimate causal effects. Well designed quasi-experiments have greater internal validity than typical observational research designs. At the same time, quasi-experiments may also have potential for greater external validity than experiments and can be implemented when randomized clinical trials are infeasible or unethical. Quasi-experimental studies have established the causal effects of HIV testing and initiation of antiretroviral therapy on health, economic outcomes and sexual behaviors, as well as indirect effects on other community members. Recent quasi-experiments have evaluated specific interventions to improve patient performance in the cascade of care, providing causal evidence to optimize clinical management of HIV. Quasi-experiments have generated important data on the real-world impacts of HIV testing and treatment and on interventions to improve the cascade of care. With the growth in large-scale clinical and administrative data, quasi-experiments enable rigorous evaluation of policies implemented in real-world settings.
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Nabe-Nielsen, Kirsten; Garde, Anne Helene; Diderichsen, Finn
2011-08-01
The aim of this study was to investigate the effect of work-time influence on stress and energy, work-family conflicts, lifestyle factors, and biomarkers of cardiovascular disease risk. The study was a quasi-experimental intervention study with a one-year follow-up among eldercare workers (baseline: n = 309; follow-up: n = 297). The nine work units in the intervention group designed their own intervention. We categorized these work units into three subgroups according to the interventions that they initiated: (A) self-scheduling via a computer program (n = 35), (B) setting up a task group that developed a questionnaire on work-time preference and participated in a one-day course on flexible working hours with the intention to increase employee influence on the fixed rota (n = 62), and (C) discussions of how employee work-time influence could be increased (n = 25). These subgroups were compared with a reference group consisting of ten work units (n = 187). Data consisted of questionnaires, blood samples, and measurements of waist and hip circumference. The employees in subgroup A became increasingly involved in the planning of their own work schedule. Nevertheless, we found no effect on health and well-being attributable to the intervention. The introduction of self-scheduling can successfully increase employee work-time influence. Yet, this study does not support the theory that increased work-time influence leads to better health and well-being.
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2013-01-01
Background Registered Nurses (RNs) play an important role in caring for patients suffering from cancer pain. A lack of knowledge regarding pain management and the RNs’ own perception of cancer pain could act as barriers to effective pain management. Educational interventions that target RNs’ knowledge and attitudes have proved promising. However, an intervention consisting of evidence-based practice is a multifaceted process and demands behavioural and cognitive changes to sustain the effects of the intervention. Therefore, our study aimed to investigate if a theory-based educational intervention could change RNs’ knowledge and attitudes to cancer pain and pain management, both four and 12 weeks after the start of the intervention. Methods A quasi-experimental design with non-equivalent control groups was used. The primary outcome was measured using a modified version of the instrument Nurses’ Knowledge and Attitudes Survey Regarding Pain (NKAS) at baseline, four weeks and 12 weeks after the start of the intervention to evaluate its persistence. The intervention’s educational curriculum was based on the principles of Ajzen’s Theory of Planned Behaviour and consisted of interactive learning activities conducted in workshops founded on evidence-based knowledge. The RN’s own experiences from cancer pain management were used in the learning process. Results The theory-based educational intervention aimed at changing RNs knowledge and attitudes regarding cancer pain management measured by primary outcome NKAS resulted in a statistical significant (p<0.05) improvement of total mean score from baseline to four weeks at the intervention ward. Conclusions The findings of this study, suggest that a theory-based educational intervention focused at RNs can be effective in changing RN’s knowledge and attitudes regarding cancer pain management. However, the high number of dropouts between baseline and four weeks needs to be taken into account when evaluating our
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Vanneste, Yvonne T M; Mathijssen, Jolanda J P; van de Goor, Ien A M; Rots-de Vries, Carin M C; Feron, Frans J M
2016-10-21
Students' health and school absenteeism affect educational level, with adverse effects on their future health. This interdependence is reflected in medical absenteeism. In the Netherlands, a public health intervention has been developed to address medical absenteeism in pre-vocational secondary education. This study aims to investigate the effectiveness of this intervention on students' medical absenteeism, compared to "medical absenteeism policy as usual". A quasi-experimental design with an intervention group (493 students) and a control group (445 students) was applied. Multilevel analysis was used to study differences in the development of the level of a student's medical absence over time (after 3 and 12 months). In the intervention group, the level of absenteeism decreased from 8.5 days reported sick in 12 school weeks to 5.7 days after 3 months, and to 4.9 days after 12 months. The number of absence periods fell from 3.9 in 12 school weeks to 2.5 after 3 months, and to 2.2 after 12 months. In the control group, the absence days initially decreased from 9.9 days reported sick in 12 school weeks to 8.4 days after 3 months, after which an increase to 8.9 days was measured. The number of absence periods initially decreased from 4.5 in 12 school weeks to 3.5, after which an increase to 3.7 was measured. The number of absence days per period remained about the same in both groups. The study provides first indications for the intervention to be effective for Dutch pre-vocational secondary students with increased medical absence rates. The intervention, which consists of personalised management of medical absenteeism by systematic identification of students with extensive medical absenteeism and consistent referral to youth health care physicians, appears to reduce the absence rates more effectively than "medical absenteeism policy as usual". The effectiveness of the intervention is shown primarily by a decrease in the number of periods reported sick.
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Gustafsson, Markus; Borglin, Gunilla
2013-08-19
Registered Nurses (RNs) play an important role in caring for patients suffering from cancer pain. A lack of knowledge regarding pain management and the RNs' own perception of cancer pain could act as barriers to effective pain management. Educational interventions that target RNs' knowledge and attitudes have proved promising. However, an intervention consisting of evidence-based practice is a multifaceted process and demands behavioural and cognitive changes to sustain the effects of the intervention. Therefore, our study aimed to investigate if a theory-based educational intervention could change RNs' knowledge and attitudes to cancer pain and pain management, both four and 12 weeks after the start of the intervention. A quasi-experimental design with non-equivalent control groups was used. The primary outcome was measured using a modified version of the instrument Nurses' Knowledge and Attitudes Survey Regarding Pain (NKAS) at baseline, four weeks and 12 weeks after the start of the intervention to evaluate its persistence. The intervention's educational curriculum was based on the principles of Ajzen's Theory of Planned Behaviour and consisted of interactive learning activities conducted in workshops founded on evidence-based knowledge. The RN's own experiences from cancer pain management were used in the learning process. The theory-based educational intervention aimed at changing RNs knowledge and attitudes regarding cancer pain management measured by primary outcome NKAS resulted in a statistical significant (p<0.05) improvement of total mean score from baseline to four weeks at the intervention ward. The findings of this study, suggest that a theory-based educational intervention focused at RNs can be effective in changing RN's knowledge and attitudes regarding cancer pain management. However, the high number of dropouts between baseline and four weeks needs to be taken into account when evaluating our findings. Finally, this kind of theory
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Ge, Weiqing; Roth, Emily; Sansone, Alyssa
2017-04-01
[Purpose] Instrument Assisted Soft Tissue Mobilization (IASTM) is a form of manual therapy. Despite its growing popularity and an increasing number of patients receiving IASTM each year, there is a lack of high-level evidence to elucidate its therapeutic mechanisms and to support its clinical applications. The purpose of this research project was to determine the effects of IASTM on activities of mechanosensitive neurons in skin. [Subjects and Methods] Twenty-three subjects, 9 females and 14 males, mean age 25.7 (SD 6.4) years old were recruited through a convenience sampling on the university campus. The study design was a quasi-experimental study using single group pretest-posttest design. The activities of mechanosensitive neurons were measured before and after the application of IASTM. [Results] The mean 2-point discrimination was 40.2 (SD 9.4) mm before IASTM and increased to 44.9 (SD 12.0) mm after IASTM. The increase was statistically significant pre and post IASTM. The mean pain threshold was 18.2 (SD 6.6) lb and increased slightly to 18.7 (SD 6.8) lb after IASTM; however, no statistical significance was found pre and post IASTM. [Conclusion] The data indicates that IASTM changes the neural activities in 2-point discrimination but not in pain threshold.
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Yang, Ke-Ping; Su, Whei-Ming; Huang, Chen-Kuan
2009-12-01
Physical stress and mental stress are increasingly common phenomena in our rapidly changing and stressful modern society. Research has found meditation to produce positive and demonstrable stress reduction effects on brain and immune functions. This study is grounded in traditional Chinese philosophical mores that teach a process summarized by the keynote activities of "calm, still, quiet, consider, and get" and the potential of this process to reduce stress in adolescents. The purpose of this study was to examine the effects of meditation on the physical and mental health of junior college students. This research employed a quasi-experimental design. Participants included 242 freshmen from a junior college in Taiwan selected using a convenience sampling technique. Participants were then randomly separated into experimental (n = 119) and control (n = 123) groups. The project duration was 18 weeks, during which the experimental group received 2 hours of meditation treatment per week, for a total of 36 hours. Both groups completed pretest and posttest Life Adaptation Scale forms, which included questionnaires addressing information on physical and mental distress and positive and negative coping strategies. Data were analyzed using analysis of covariance. Findings showed that the effect of the experiment treatment was significant when student physical and mental distress pretest scores were controlled. Physical and mental symptoms in the experimental group were lower than those in the control group. Meditation can help students to adapt to life stressors. This study also provides support for traditional Chinese wisdom, which promotes meditation as one way to improve health.
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Bernstein, Kunsook; Park, So-Young; Hahm, Sohee; Lee, Young Na; Seo, Jin Young; Nokes, Kathleen M
2016-02-01
Asian American women are more prone to suffer from depression compared to their non-Asian American counterparts and have lower rates of seeking mental healthcare services due to lack of available culturally appropriate therapies. Two prior studies of a culturally tailored therapeutic intervention called LogoAutobiography were helpful in treating depressed Korean American women. The LogoAutobiography program was revised to enhance its efficacy not only for depressive symptoms and purpose in life but also to increase coping strategies. To test the efficacy of the Enhanced LogoAutobiography program on depressive symptoms, purpose in life, and coping strategies of depressed community-dwelling Korean American women. Two-group, non-randomized quasi-experimental design. Local Korean community areas located in New York City and eastern New Jersey of the United States. A total of 54 depressed women with Korean heritage completed either experimental group (n1=25) or control group (n2=29). Sample inclusion criteria were adult women with Korean heritage, depressive symptoms as measured by a CES-D score 16 or higher, fluent Korean language, and able to participate independently. Sample exclusion criteria were those who presented active suicidal ideation and history of episodes of mania or psychosis screened by the psychosocial survey questionnaire. The experimental group received Enhanced Logo-Autobiography program which was guided by a facilitator who used a manualized intervention for 90minute sessions over 8weeks; the control group attended routine weekly community activities. Data were collected during the first session (pretest), the end of 8weeks (posttest), and the 3months follow-up session. Time and group changes in depressive symptoms, purpose in life, and coping strategies were computed using Repeated Measures General Linear Model (RMGLM). Findings suggested that the experimental group showed greater improvement in depressive symptoms (F=6.94 (2, 88), p<0.01), active
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A reflective-type, quasi-optical metasurface filter
NASA Astrophysics Data System (ADS)
Sima, Boyu; Momeni Hasan Abadi, Seyed Mohamad Amin; Behdad, Nader
2017-08-01
We introduce a new technique for designing quasi-optical, reflective-type spatial filters. The proposed filter is a reflective metasurface with a one dimensional, frequency-dependent phase gradient along the aperture. By careful design of each unit cell of the metasurface, the phase shift gradient provided by the adjacent unit cells can be engineered to steer the beam towards a desired, anomalous reflection direction over the passband region of the filter. Outside of that range, the phase shift gradient required to produce the anomalous reflection is not present and hence, the wave is reflected towards the specular reflection direction. This way, the metasurface acts as a reflective filter in a quasi-optical system where the detector is placed along the direction of anomalous reflection. The spectral selectivity of this filter is determined by the frequency dispersion of the metasurface's phase response. Based on this principle, a prototype of the proposed metasurface filter, which operates at 10 GHz and has a bandwidth of 3%, is designed. The device is modeled using a combination of theoretical analysis using the phased-array theory and full-wave electromagnetic simulations. A prototype of this device is also fabricated and characterized using a free-space measurement system. Experimental results agree well with the simulations.
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Ekstam, Lisa; Carlsson, Gunilla; Chiatti, Carlos; Nilsson, Maria H; Malmgren Fänge, Agneta
2014-11-29
The primary aim of this paper is to describe the design of a project evaluating the effects of using a research-based strategy for managing housing adaptations (HAs). The evaluation targets clients' perspectives in terms of activity, participation, usability, fear of falling, fall incidence, use of mobility devices, and health-related quality of life, and determines the societal effects of HAs in terms of costs. Additional aims of the project are to explore and describe this strategy in relation to experiences and expectations (a) among clients and cohabitants and (b) occupational therapists in ordinary practice. This study is a quasi-experimental trial applying a multiphase design, combining quantitative and qualitative data. At the experimental sites, the occupational therapists (OTs) apply the intervention, i.e. a standardized research-based strategy for HA case management. At the control site, the occupational therapists are following their regular routine in relation to HA. Three municipalities in south Sweden will be included based on their population, their geographical dispersion, and their similar organizational structures for HA administration. Identical data on outcomes is being collected at all the sites at the same four time points: before the HA and then 3, 6, and 12 months after the HA. The data-collection methods are semi-structured qualitative interviews, observations, clinical assessments, and certificates related to each client's HA. The intervention in this study has been developed and tested through many years of research and in collaboration with practitioners. This process includes methodological development and testing research aimed at identifying the most important outcomes and research targeting current HA case-management procedures in Swedish municipalities. When the study is completed, the results will be used for further optimization of the practice strategy for HA, in close collaboration with the data-collecting OTs. No: NCT01960582.
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Friche, Amélia Augusta de Lima; Dias, Maria Angélica de Salles; Reis, Priscila Brandão Dos; Dias, Cláudia Silva; Caiaffa, Waleska Teixeira
2015-11-01
There is little scientific evidence that urban upgrading helps improve health or reduce inequities. This article presents the design for the BH-Viva Project, a "quasi-experimental", multiphase, mixed-methods study with quantitative and qualitative components, proposing an analytical model for monitoring the effects that interventions in the urban environment can have on residents' health in slums in Belo Horizonte, Minas Gerais State, Brazil. A preliminary analysis revealed intra-urban differences in age-specific mortality when comparing areas with and without interventions; the mortality rate from 2002 to 2012 was stable in the "formal city", increased in slums without interventions, and decreased in slums with interventions. BH-Viva represents an effort at advancing methodological issues, providing learning and theoretical backing for urban health research and research methods, allowing their application and extension to other urban contexts.
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Design and characterization of a biologically inspired quasi-passive prosthetic ankle-foot.
Mooney, Luke M; Lai, Cara H; Rouse, Elliott J
2014-01-01
By design, commonly worn energy storage and release (ESR) prosthetic feet cannot provide biologically realistic ankle joint torque and angle profiles during walking. Additionally, their anthropomorphic, cantilever architecture causes their mechanical stiffness to decrease throughout the stance phase of walking, opposing the known trend of the biological ankle. In this study, the design of a quasi-passive pneumatic ankle-foot prosthesis is detailed that is able to replicate the biological ankle's torque and angle profiles during walking. The prosthetic ankle is comprised of a pneumatic piston, bending spring and solenoid valve. The mechanical properties of the pneumatic ankle prosthesis are characterized using a materials testing machine and the properties are compared to those from a common, passive ESR prosthetic foot. The characterization spanned a range of ankle equilibrium pressures and testing locations beneath the foot, analogous to the location of center of pressure within the stance phase of walking. The pneumatic ankle prosthesis was shown to provide biologically appropriate trends and magnitudes of torque, angle and stiffness behavior, when compared to the passive ESR prosthetic foot. Future work will focus on the development of a control system for the quasi-passive device and clinical testing of the pneumatic ankle to demonstrate efficacy.
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ERIC Educational Resources Information Center
Harper, Gary W.; Bangi, Audrey K.; Sanchez, Bernadette; Doll, Mimi; Pedraza, Ana
2009-01-01
This article describes a quasi-experimental evaluation of a community-based, culturally and ecologically tailored HIV prevention intervention for Mexican American female adolescents grounded in the AIDS risk reduction model. A total of 378 Mexican American female adolescents (mean age = 15.2) participated in either the nine-session SHERO's (a…
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Storm, Marianne; Schulz, Jörn; Aase, Karina
2018-01-01
Objective The study objective was to assess the effects of an interorganisational educational intervention called the ‘Meeting Point’ on patient safety culture among staff in hospital and nursing home wards. Design The study employs a quasi-experimental, non-randomised design with a hospital and nursing home intervention group and a hospital and nursing home control group. The study uses one preintervention and two postintervention survey measurements. The intervention group participated in an educational programme ‘The Meeting Point’ including interorganisational staff meetings combining educational sessions with a discussion platform focusing on quality and safety in transitional care of the elderly. Results The results show a stable development over time for the patient safety culture factor ‘Handoff and transitions’, and small improvements for ‘Overall perceptions of patient safety culture’ and ‘Organisational learning - continuous improvement’ for the hospital intervention group. No similar development was reported in the nursing home intervention group, which is most likely explained by ongoing organisational changes. Qualitative data show the existence of ongoing initiatives in the hospital to improve transitional care, but not all were connected to the ‘Meeting Point’. Conclusion The ‘Meeting Point’ has the potential to be a useful measure for healthcare professionals when aiming to improve patient safety culture in transitional care. Further refinement of the key components and testing with a more robust study design will be beneficial. PMID:29391363
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Quasi-isotropic VHF antenna array design study for the International Ultraviolet Explorer satellite
NASA Technical Reports Server (NTRS)
Raines, J. K.
1975-01-01
Results of a study to design a quasi-isotropic VHF antenna array for the IUE satellite are presented. A free space configuration was obtained that has no nulls deeper than -6.4 dbi in each of two orthogonal polarizations. A computer program named SOAP that analyzes the electromagnetic interaction between antennas and complicated conducting bodies, such as satellites was developed.
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Fry, Derek J
2014-01-01
Awareness of poor design and published concerns over study quality stimulated the development of courses on experimental design intended to improve matters. This article describes some of the thinking behind these courses and how the topics can be presented in a variety of formats. The premises are that education in experimental design should be undertaken with an awareness of educational principles, of how adults learn, and of the particular topics in the subject that need emphasis. For those using laboratory animals, it should include ethical considerations, particularly severity issues, and accommodate learners not confident with mathematics. Basic principles, explanation of fully randomized, randomized block, and factorial designs, and discussion of how to size an experiment form the minimum set of topics. A problem-solving approach can help develop the skills of deciding what are correct experimental units and suitable controls in different experimental scenarios, identifying when an experiment has not been properly randomized or blinded, and selecting the most efficient design for particular experimental situations. Content, pace, and presentation should suit the audience and time available, and variety both within a presentation and in ways of interacting with those being taught is likely to be effective. Details are given of a three-day course based on these ideas, which has been rated informative, educational, and enjoyable, and can form a postgraduate module. It has oral presentations reinforced by group exercises and discussions based on realistic problems, and computer exercises which include some analysis. Other case studies consider a half-day format and a module for animal technicians. © The Author 2014. Published by Oxford University Press on behalf of the Institute for Laboratory Animal Research. All rights reserved. For permissions, please email: journals.permissions@oup.com.
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Viani, Gustavo Arruda; Sakamoto, Aline
2017-07-01
The aim of this quasi-experimental study is to evaluate a novel technique for an outpatient application of formalin for chronic rectal bleeding after prostate irradiation. This is a quasi- experimental clinical trial developed between January 2010 and July 2015, including 35 patients with chronic radiation rectitis (CRP) due to a previous prostate radiation course. The study's eligibility was (1) completed external beam radiation therapy for prostate carcinoma >6 months previously, (2) rectal bleeding, defined as a frequency of >1× per week and/or needing of blood transfusions, and (3) diagnosis of chronic proctitis at colonoscopy. The 5% formalin application was performed by a custom applicator, which requires neither anesthesia nor sigmoidoscopy. The endpoint of the study was bleeding cessation and hemoglobin level. The onset of bleeding due to chronic rectitis was 12 months (6-36). During a median follow-up of 24 months, the rate of overall efficacy was 94%. The sustained complete response in 1 and 2 years was 80% and 73%, respectively. The Hb mean pre- and post-treatment differed significantly (12.2 vs 14.4, p = 0.0001). The rates of blood transfusion differed significantly, pre- and post-treatment (17% vs 5.7%, p = 0.031). The technique is very effective and safe, resulting to a significant improvement of hemoglobin levels and quality of life scores. Further studies are warranted to compare this technique with other treatment options for chronic radiation-induced rectal bleeding.
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Numerical simulations of quasi-perpendicular collisionless shocks
NASA Technical Reports Server (NTRS)
Goodrich, C. C.
1985-01-01
Numerical simulations of collisionless quasi-perpendicular shock waves are reviewed. The strengths and limitations of these simulations are discussed and their experimental (laboratory and spacecraft) context is given. Recent simulation results are emphasized that, with ISEE bow shock observations, are responsible for recent progress in understanding quasi-steady shock structure.
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Experimental validation of a quasi-steady theory for the flow through the glottis
NASA Astrophysics Data System (ADS)
Vilain, C. E.; Pelorson, X.; Fraysse, C.; Deverge, M.; Hirschberg, A.; Willems, J.
2004-09-01
In this paper a theoretical description of the flow through the glottis based on a quasi-steady boundary layer theory is presented. The Thwaites method is used to solve the von Kármán equations within the boundary layers. In practice this makes the theory much easier to use compared to Pohlhausen's polynomial approximations. This theoretical description is evaluated on the basis of systematic comparison with experimental data obtained under steady flow or unsteady (oscillating) flow without and with moving vocal folds. Results tend to show that the theory reasonably explains the measured data except when unsteady or viscous terms become predominant. This happens particularly during the collision of the vocal folds.
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Feasibility of quasi-random band model in evaluating atmospheric radiance
NASA Technical Reports Server (NTRS)
Tiwari, S. N.; Mirakhur, N.
1980-01-01
The use of the quasi-random band model in evaluating upwelling atmospheric radiation is investigated. The spectral transmittance and total band adsorptance are evaluated for selected molecular bands by using the line by line model, quasi-random band model, exponential sum fit method, and empirical correlations, and these are compared with the available experimental results. The atmospheric transmittance and upwelling radiance were calculated by using the line by line and quasi random band models and were compared with the results of an existing program called LOWTRAN. The results obtained by the exponential sum fit and empirical relations were not in good agreement with experimental results and their use cannot be justified for atmospheric studies. The line by line model was found to be the best model for atmospheric applications, but it is not practical because of high computational costs. The results of the quasi random band model compare well with the line by line and experimental results. The use of the quasi random band model is recommended for evaluation of the atmospheric radiation.
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Seliner, Brigitte; Latal, Beatrice; Spirig, Rebecca
2017-07-01
The aim of this study was to assess the effectiveness of a family-centered care (FCC) intervention provided by an advanced practice nurse (APN) for parents of children with profound disabilities undergoing surgery. In a quasi-experimental design, we used the MPOC-20 to assess satisfaction with FCC and interviews to identify potential mechanisms for improving satisfaction. There was a positive effect on the MPOC-20 domain "general information," albeit with a small effect size (Cohen's d = 0.35). The interviewed parents expected additional support. Emphasis should be placed on providing comprehensive care coordination by an experienced APN. Shared care management is crucial in improving FCC. © 2017 Wiley Periodicals, Inc.
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The Experimental Design Assistant.
Percie du Sert, Nathalie; Bamsey, Ian; Bate, Simon T; Berdoy, Manuel; Clark, Robin A; Cuthill, Innes; Fry, Derek; Karp, Natasha A; Macleod, Malcolm; Moon, Lawrence; Stanford, S Clare; Lings, Brian
2017-09-01
Addressing the common problems that researchers encounter when designing and analysing animal experiments will improve the reliability of in vivo research. In this article, the Experimental Design Assistant (EDA) is introduced. The EDA is a web-based tool that guides the in vivo researcher through the experimental design and analysis process, providing automated feedback on the proposed design and generating a graphical summary that aids communication with colleagues, funders, regulatory authorities, and the wider scientific community. It will have an important role in addressing causes of irreproducibility.
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The effects of footbath on sleep among the older adults in nursing home: A quasi-experimental study.
Kim, Hyun-Joo; Lee, Yaelim; Sohng, Kyeong-Yae
2016-06-01
To examine the long-term effects of foot-bathing therapy, using different water temperatures, on the sleep quality of older adults living in nursing homes. A quasi-experimental study design with non-equivalent control group. Thirty participants were recruited from a nursing home in Gyeong-gi Province, South Korea. The participants were randomly assigned to experimental, placebo, and control groups. The foot-bathing therapy was performed for 30min daily for four weeks. Water at 40°C was used for the experimental group, while water at 36.5°C was used for the placebo group. The control group did not receive any intervention. The participants' sleep patterns (total sleep amount, sleep efficiency, and sleep latency) and sleep-disturbed behaviors were compared based on group, using actigraphy and a sleep disorder inventory. The total amount of sleep and sleep efficiency were significantly different for the experimental group, especially those with poor sleep quality. There were no differences in sleep latency or sleep-disturbed behaviors among the groups. The long-term effect of the therapy decreased in the third week of the therapy. Daily, 30-min foot-bathing therapy sessions with water at 40°C were effective in improving sleep quality for older adults. The therapy was more effective for participants with poor sleep quality at baseline assessment than those with relatively good sleep quality. The long-term effects of foot-bathing therapy decreased three weeks after initiation; therefore, it might be desirable to deliver the therapy for two weeks, pause it for a week, and then resume it. Copyright © 2016 Elsevier Ltd. All rights reserved.
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Boucher, Danielle; Gagné, Camille; Côté, Françoise
2015-01-01
This study evaluates the effectiveness of an intervention mapping developed to promote fruit and vegetable consumption. Students (n = 394) from two similar public colleges in the Quebec City area (Canada) were asked to participate. A quasi-experimental design was used with a 14-week pause between the pretest and posttest. The control and experimental groups both received information on Canada's Food Guide recommendations. The experimental group was submitted to an intervention consisting of six interactive workshops carried out inside the college, and three personal exercises to be completed at home. proportion of respondents consuming at least five servings of fruits and vegetables daily. psychosocial variables assessed (theory of planned behaviour). The data collected from 344 participants by means of a self-administered questionnaire were analysed (167 experimental and 177 control). The posttest revealed a significant increase (15%) in the number of participants in the experimental group achieving the primary outcome (d = .38). The intervention also had a significant effect on the targeted psychosocial variables (η(2) = .03 to .06). Regularity of consumption acts as a mediator between intention and behaviour. These results may be used to guide health promoters working with college students.
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The Experimental Design Assistant
Bamsey, Ian; Bate, Simon T.; Berdoy, Manuel; Clark, Robin A.; Cuthill, Innes; Fry, Derek; Karp, Natasha A.; Macleod, Malcolm; Moon, Lawrence; Stanford, S. Clare; Lings, Brian
2017-01-01
Addressing the common problems that researchers encounter when designing and analysing animal experiments will improve the reliability of in vivo research. In this article, the Experimental Design Assistant (EDA) is introduced. The EDA is a web-based tool that guides the in vivo researcher through the experimental design and analysis process, providing automated feedback on the proposed design and generating a graphical summary that aids communication with colleagues, funders, regulatory authorities, and the wider scientific community. It will have an important role in addressing causes of irreproducibility. PMID:28957312
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ERIC Educational Resources Information Center
Campero, Lourdes; Walker, Dilys; Atienzo, Erika E.; Gutierrez, Juan Pablo
2011-01-01
Objective: To evaluate the effectiveness of an educational intervention for parents of first year high school students in the State of Morelos, Mexico, whose aim was to impact adolescents' sexual behavior, knowledge and access to contraception. Material and methods: Quasi-experimental prospective study with eleven control and eleven intervention…
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Yuan, Haobin; Kunaviktikul, Wipada; Klunklin, Areewan; Williams, Beverly A
2008-03-01
A quasi-experimental, two-group pretest-post-test design was conducted to examine the effect of problem-based learning on the critical thinking skills of 46 Year 2 undergraduate nursing students in the People's Republic of China. The California Critical Thinking Skills Test Form A, Chinese-Taiwanese version was used as both a pretest and as a post-test for a semester-long nursing course. There was no significant difference in critical thinking skills at pretest, whereas, significant differences in critical thinking skills existed between the problem-based learning and lecture groups at post-test. The problem-based learning students had a significantly greater improvement on the overall California Critical Thinking Skills Test, analysis, and induction subscale scores compared with the lecture students. Problem-based learning fostered nursing students' critical thinking skills.
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NASA Astrophysics Data System (ADS)
Chen, Michael; Abdo-Sánchez, Elena; Epstein, Ariel; Eleftheriades, George V.
2018-03-01
Huygens' metasurfaces are electrically thin devices which allow arbitrary field transformations. Beam refraction is among the first demonstrations of realized metasurfaces. As previously shown for extreme-angle refraction, control over only the electric impedance and magnetic admittance of the Huygens' metasurface proved insufficient to produce the desired reflectionless field transformation. To maintain zero reflections for wide refraction angles, magnetoelectric coupling between the electric and magnetic response of the metasurface, leading to bianisotropy, can be introduced. In this paper, we report the theory, design, and experimental characterization of a reflectionless bianisotropic metasurface for extreme-angle refraction of a normally incident plane wave towards 71.8° at 20 GHz. The theory and design of three-layer asymmetric bianisotropic unit cells are discussed. The realized printed circuit board structure was tested via full-wave simulations as well as experimental characterization. To experimentally verify the prototype, two setups were used. A quasi-optical experiment was conducted to assess the specular reflections of the metasurface, while a far-field antenna measurement characterized its refraction nature. The measurements verify that the fabricated metasurface has negligible reflections and the majority of the scattered power is refracted to the desired Floquet mode. This provides an experimental demonstration of a reflectionless wide-angle refracting metasurface using a bianisotropic Huygens' metasurface at microwave frequencies.
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Ebrahimi Moghadam, Hosein; Karimi, Ahoo; Seifi, Kimia
2017-01-01
This study aimed to investigate the effectiveness of cognitive-behavioral therapy on relieving migraine headaches in migraine sufferers. In this quasi-experimental study with pre-test and post-test method, the samples were outpatients of public hospitals in Ilam City, southwestern Iran since May-Jul 2010. They were selected based on inclusion and exclusion criteria, and divided into experimental and control groups. The data were analyzed using SPSS ver. 16 and via multivariate covariance method. Cognitive-behavioral therapy affected on reducing the duration of symptoms of migraine in sufferers ( P <0.05). Cognitive behavioral therapy effects on reducing the time duration of symptoms of migraine headaches. Thistherapeutic method increases the level of individual, familial, social and occupational activities by reducing the time duration of symptoms and this method helps the individuals to resume their activities and regain their previous control instead of founding themselves incapable and helpless due to the pain they suffer from.
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Lee, Kwo-Chen; Yu, Chin-Ching; Hsieh, Pei-Ling; Li, Chin-Ching; Chao, Yann-Fen C
2018-05-01
Empathy is an important clinical skill for nursing students, but it is a characteristic difficult to teach and assess. To evaluate the effect of situated teaching on empathy learning among undergraduate nursing students. A cohort study with pre-post-test quasi-experimental design. The 2nd-year students were enrolled from two BSN programs. The teaching program was completed over 4 months on the basis of experiential learning theory which integrated the following four elements: classroom-based role play, self-reflection, situated learning and acting. The Jefferson Scale of Empathy-Health Profession-Student version was administered before and after the program. Objective Structure Clinical Examination (OSCE) was administered at the end of program and a rubrics scale was used to measure empathy. A generalized estimation equation was used to identify the effect of subjective empathy, and an independent t-test was used for the objective assessment between two groups. A total of 103 students were enrolled. The results showed that subjective empathy increased significantly in experimental group. In the Objective Structured Clinical Examination, examiners and standard patients gave significantly higher empathy scores to the situated teaching group than the control group. The present study indicated that situated teaching can improve empathy learning of the nursing students. However different methods of assessment of empathy produce different results. We therefore recommend that multiple measurements from difference perspectives are preferable in the assessment of empathy. Copyright © 2018 Elsevier Ltd. All rights reserved.
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Estimation of Quasi-Stiffness of the Human Knee in the Stance Phase of Walking
Shamaei, Kamran; Sawicki, Gregory S.; Dollar, Aaron M.
2013-01-01
Biomechanical data characterizing the quasi-stiffness of lower-limb joints during human locomotion is limited. Understanding joint stiffness is critical for evaluating gait function and designing devices such as prostheses and orthoses intended to emulate biological properties of human legs. The knee joint moment-angle relationship is approximately linear in the flexion and extension stages of stance, exhibiting nearly constant stiffnesses, known as the quasi-stiffnesses of each stage. Using a generalized inverse dynamics analysis approach, we identify the key independent variables needed to predict knee quasi-stiffness during walking, including gait speed, knee excursion, and subject height and weight. Then, based on the identified key variables, we used experimental walking data for 136 conditions (speeds of 0.75–2.63 m/s) across 14 subjects to obtain best fit linear regressions for a set of general models, which were further simplified for the optimal gait speed. We found R2 > 86% for the most general models of knee quasi-stiffnesses for the flexion and extension stages of stance. With only subject height and weight, we could predict knee quasi-stiffness for preferred walking speed with average error of 9% with only one outlier. These results provide a useful framework and foundation for selecting subject-specific stiffness for prosthetic and exoskeletal devices designed to emulate biological knee function during walking. PMID:23533662
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Semahegn, Agumasie; Torpey, Kwasi; Manu, Abubakar; Assefa, Nega; Ankomah, Augustine
2017-11-21
Violence against women is a well understood devastating global pandemic, and human right violation. One in three women experienced intimate partner violence worldwide. In Ethiopia, the level of domestic violence against women is one of the highest in the world. However, Ethiopia is signatory for various conventions and incorporated in legal frameworks. Nevertheless, effective implementation of the existing policy documents, and engaging different stakeholders is very limited. Therefore, we aimed to pilot feasibility of implementing available research evidence and policy documents at community level to prevent domestic violence against women in Awi zone, northwestern Ethiopia. A community-based quasi-experimental study design will be employed using mixed method. Multistage stratified systematic sampling and purposive sampling will be used to recruit quantitative and qualitative study participants, respectively. A total of 1,269 women will be participated in the intervention, active comparator and control groups. Pre and post-test quantitative data will be collected using face-to-face interview. Qualitative data will be collected through in-depth, key informant interview and focus group discussions. advocacy meeting will be held to persuade local politicians and sustain the implementation of community based intervention to prevent domestic violence against women. Community representatives will be trained to enhance peer education to promote community awareness and engage stakeholders to transform the traditional gender norm within local context. Awareness creation and husband involvement will be made through integrating the intervention with community health extension program. Only husband involvement will not be promoted in the active comparator to test the role of husband involvement on the domestic violence prevention activities. Intervention progress will be monitored regularly. Gathered data will be entered in Epidata and exported to SPSS (23.0) software for
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ERIC Educational Resources Information Center
Saunders, William M.; Goldenberg, Claude N.; Gallimore, Ronald
2009-01-01
The authors conducted a quasi-experimental investigation of effects on achievement by grade-level teams focused on improving learning. For 2 years (Phase 1), principals-only training was provided. During the final 3 years (Phase 2), school-based training was provided for principals and teacher leaders on stabilizing team settings and using…
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ERIC Educational Resources Information Center
Mokher, Christine; Cavalluzzo, Linda
2011-01-01
This presentation focuses on the quasi-experimental methods used to select comparison schools for an evaluation of a federal investing in innovation (i3) validation grant. The Northeast Tennessee College and Career Ready Consortium (NETCO) consists of 29 high schools participating in a five-year program to expand students' access to rigorous…
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Klaja, P.; Janusz, M.; Jarczyk, L.
2005-10-26
The COSY-11 experimental setup is an internal facility installed at the COoler SYnchrotron COSY in Juelich. It allows to investigate meson production in free and quasi-free nucleon-nucleon collisions, eg. pp {yields} pp meson and pd {yields} pspnp meson reactions. Drift chambers and scintillators permit to measure outgoing protons, separated in the magnetic field of the COSY-11 dipole. Neutrons are registered in the neutron modular detector installed downstream from the target. Recently, the experimental setup has been extended with spectator detector, deuteron drift chamber and polarization monitoring system, and since then meson production can be investigated also as a function ofmore » spin and isospin of colliding nucleons.« less
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Oluyomi, Abiodun O; Byars, Allison; Byrd-Williams, Courtney; Sharma, Shreela V; Durand, Casey; Hoelscher, Deanna M; Butte, Nancy F; Kelder, Steven H
2015-02-01
The Texas Childhood Obesity Research Demonstration project (TX CORD) uses a systems-oriented approach to address obesity that includes individual and family interventions, community-level action, as well as environmental and policy initiatives. Given that randomization is seldom possible in community-level intervention studies, TX CORD uses a quasi-experimental design. Comparable intervention and comparison study sites are needed to address internal validity bias. TX CORD was designed to be implemented in low-income, ethnically diverse communities in Austin and Houston, Texas. A three-stage Geographical Information System (GIS) methodology was used to establish and ascertain the comparability of the intervention and comparison study sites. Census tract (stage 1) and school (stage 2) data were used to identify spatially exclusive geographic areas that were comparable. In stage 3, study sites were compared on demographic characteristics, socioeconomic status (SES), food assets, and physical activity (PA) assets. Student's t-test was used to examine significant differences between the selected sites. The methodology that was used resulted in the selection of catchment areas with demographic and socioeconomic characteristics that fit the target population: ethnically diverse population; lower-median household income; and lower home ownership rates. Additionally, the intervention and comparison sites were statistically comparable on demographic and SES variables, as well as food assets and PA assets. This GIS approach can provide researchers, program evaluators, and policy makers with useful tools for both research and practice. Area-level information that allows for robust understanding of communities can enhance analytical procedures in community health research and offer significant contributions in terms of community assessment and engagement.
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Quasi-cylindrical wave contribution in experiments on extraordinary optical transmission.
van Beijnum, Frerik; Rétif, Chris; Smiet, Chris B; Liu, Haitao; Lalanne, Philippe; van Exter, Martin P
2012-12-20
A metal film perforated by a regular array of subwavelength holes shows unexpectedly large transmission at particular wavelengths, a phenomenon known as the extraordinary optical transmission (EOT) of metal hole arrays. EOT was first attributed to surface plasmon polaritons, stimulating a renewed interest in plasmonics and metallic surfaces with subwavelength features. Experiments soon revealed that the field diffracted at a hole or slit is not a surface plasmon polariton mode alone. Further theoretical analysis predicted that the extra contribution, from quasi-cylindrical waves, also affects EOT. Here we report the experimental demonstration of the relative importance of surface plasmon polaritons and quasi-cylindrical waves in EOT by considering hole arrays of different hole densities. From the measured transmission spectra, we determine microscopic scattering parameters which allow us to show that quasi-cylindrical waves affect EOT only for high densities, when the hole spacing is roughly one wavelength. Apart from providing a deeper understanding of EOT, the determination of microscopic scattering parameters from the measurement of macroscopic optical properties paves the way to novel design strategies.
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Experimental design methods for bioengineering applications.
Keskin Gündoğdu, Tuğba; Deniz, İrem; Çalışkan, Gülizar; Şahin, Erdem Sefa; Azbar, Nuri
2016-01-01
Experimental design is a form of process analysis in which certain factors are selected to obtain the desired responses of interest. It may also be used for the determination of the effects of various independent factors on a dependent factor. The bioengineering discipline includes many different areas of scientific interest, and each study area is affected and governed by many different factors. Briefly analyzing the important factors and selecting an experimental design for optimization are very effective tools for the design of any bioprocess under question. This review summarizes experimental design methods that can be used to investigate various factors relating to bioengineering processes. The experimental methods generally used in bioengineering are as follows: full factorial design, fractional factorial design, Plackett-Burman design, Taguchi design, Box-Behnken design and central composite design. These design methods are briefly introduced, and then the application of these design methods to study different bioengineering processes is analyzed.
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Wang, Su-Chin; Yu, Ching-Len; Chang, Su-Hsien
2017-02-01
The purpose was to examine the effectiveness of music care on cognitive function, depression, and behavioral problems among elderly people with dementia in long-term care facilities in Taiwan. The study had a quasi-experimental, longitudinal research design and used two groups of subjects. Subjects were not randomly assigned to experimental group (n = 90) or comparison group (n = 56). Based on Bandura's social cognition theory, subjects in the experimental group received Kagayashiki music care (KMC) twice per week for 24 weeks. Subjects in the comparison group were provided with activities as usual. Results found, using the control score of the Clifton Assessment Procedures for the Elderly Behavior Rating Scale (baseline) and time of attending KMC activities as a covariate, the two groups of subjects had statistically significant differences in the mini-mental state examination (MMSE). Results also showed that, using the control score of the Cornell Scale for Depression in Dementia (baseline) and MMSE (baseline) as a covariate, the two groups of subjects had statistically significant differences in the Clifton Assessment Procedures for the Elderly Behavior Rating Scale. These findings provide information for staff caregivers in long-term care facilities to develop a non-invasive care model for elderly people with dementia to deal with depression, anxiety, and behavioral problems.
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Experimental design matters for statistical analysis: how to handle blocking.
Jensen, Signe M; Schaarschmidt, Frank; Onofri, Andrea; Ritz, Christian
2018-03-01
Nowadays, evaluation of the effects of pesticides often relies on experimental designs that involve multiple concentrations of the pesticide of interest or multiple pesticides at specific comparable concentrations and, possibly, secondary factors of interest. Unfortunately, the experimental design is often more or less neglected when analysing data. Two data examples were analysed using different modelling strategies. First, in a randomized complete block design, mean heights of maize treated with a herbicide and one of several adjuvants were compared. Second, translocation of an insecticide applied to maize as a seed treatment was evaluated using incomplete data from an unbalanced design with several layers of hierarchical sampling. Extensive simulations were carried out to further substantiate the effects of different modelling strategies. It was shown that results from suboptimal approaches (two-sample t-tests and ordinary ANOVA assuming independent observations) may be both quantitatively and qualitatively different from the results obtained using an appropriate linear mixed model. The simulations demonstrated that the different approaches may lead to differences in coverage percentages of confidence intervals and type 1 error rates, confirming that misleading conclusions can easily happen when an inappropriate statistical approach is chosen. To ensure that experimental data are summarized appropriately, avoiding misleading conclusions, the experimental design should duly be reflected in the choice of statistical approaches and models. We recommend that author guidelines should explicitly point out that authors need to indicate how the statistical analysis reflects the experimental design. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.
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Sarbaz, Masoumeh; Kimiafar, Khalil; Taherzadeh, Zhila; Naderi, HamidReza; Eslami, Saeid
2017-01-01
This study was a quasi-experimental design to assess the effect of a Web-based information system on the occupational exposure to blood and body fluids (BBFs) among health care workers (HCWs). The outcome was the number of exposure incidents with BBFs among HCWs in both hospital A (intervention) and hospital B (control). The findings showed that the implementation of the Web-based information system about infection prevention and control in hospital A decreased exposure incidents with BBFs among the HCWs (P < .001). Copyright © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.
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Entropy-Based Search Algorithm for Experimental Design
NASA Astrophysics Data System (ADS)
Malakar, N. K.; Knuth, K. H.
2011-03-01
The scientific method relies on the iterated processes of inference and inquiry. The inference phase consists of selecting the most probable models based on the available data; whereas the inquiry phase consists of using what is known about the models to select the most relevant experiment. Optimizing inquiry involves searching the parameterized space of experiments to select the experiment that promises, on average, to be maximally informative. In the case where it is important to learn about each of the model parameters, the relevance of an experiment is quantified by Shannon entropy of the distribution of experimental outcomes predicted by a probable set of models. If the set of potential experiments is described by many parameters, we must search this high-dimensional entropy space. Brute force search methods will be slow and computationally expensive. We present an entropy-based search algorithm, called nested entropy sampling, to select the most informative experiment for efficient experimental design. This algorithm is inspired by Skilling's nested sampling algorithm used in inference and borrows the concept of a rising threshold while a set of experiment samples are maintained. We demonstrate that this algorithm not only selects highly relevant experiments, but also is more efficient than brute force search. Such entropic search techniques promise to greatly benefit autonomous experimental design.
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Karam, Eli A; Sterrett, Emma M; Kiaer, Lynn
2017-06-01
The current study employed a quasi-experimental design using both intent-to-treat and protocol adherence analysis of 155 moderate- to high-risk juvenile offenders to evaluate the effectiveness of Parenting with Love and Limits® (PLL), an integrative group and family therapy approach. Youth completing PLL had significantly lower rates of recidivism than the comparison group. Parents also reported statistically significant improvements in youth behavior. Lengths of service were also significantly shorter for the treatment sample than the matched comparison group by an average of 4 months. This study contributes to the literature by suggesting that intensive community-based combined family and group treatment is effective in curbing recidivism among high-risk juveniles. © 2015 Family Process Institute.
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Design approaches to experimental mediation☆
Pirlott, Angela G.; MacKinnon, David P.
2016-01-01
Identifying causal mechanisms has become a cornerstone of experimental social psychology, and editors in top social psychology journals champion the use of mediation methods, particularly innovative ones when possible (e.g. Halberstadt, 2010, Smith, 2012). Commonly, studies in experimental social psychology randomly assign participants to levels of the independent variable and measure the mediating and dependent variables, and the mediator is assumed to causally affect the dependent variable. However, participants are not randomly assigned to levels of the mediating variable(s), i.e., the relationship between the mediating and dependent variables is correlational. Although researchers likely know that correlational studies pose a risk of confounding, this problem seems forgotten when thinking about experimental designs randomly assigning participants to levels of the independent variable and measuring the mediator (i.e., “measurement-of-mediation” designs). Experimentally manipulating the mediator provides an approach to solving these problems, yet these methods contain their own set of challenges (e.g., Bullock, Green, & Ha, 2010). We describe types of experimental manipulations targeting the mediator (manipulations demonstrating a causal effect of the mediator on the dependent variable and manipulations targeting the strength of the causal effect of the mediator) and types of experimental designs (double randomization, concurrent double randomization, and parallel), provide published examples of the designs, and discuss the strengths and challenges of each design. Therefore, the goals of this paper include providing a practical guide to manipulation-of-mediator designs in light of their challenges and encouraging researchers to use more rigorous approaches to mediation because manipulation-of-mediator designs strengthen the ability to infer causality of the mediating variable on the dependent variable. PMID:27570259
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Design approaches to experimental mediation.
Pirlott, Angela G; MacKinnon, David P
2016-09-01
Identifying causal mechanisms has become a cornerstone of experimental social psychology, and editors in top social psychology journals champion the use of mediation methods, particularly innovative ones when possible (e.g. Halberstadt, 2010, Smith, 2012). Commonly, studies in experimental social psychology randomly assign participants to levels of the independent variable and measure the mediating and dependent variables, and the mediator is assumed to causally affect the dependent variable. However, participants are not randomly assigned to levels of the mediating variable(s), i.e., the relationship between the mediating and dependent variables is correlational. Although researchers likely know that correlational studies pose a risk of confounding, this problem seems forgotten when thinking about experimental designs randomly assigning participants to levels of the independent variable and measuring the mediator (i.e., "measurement-of-mediation" designs). Experimentally manipulating the mediator provides an approach to solving these problems, yet these methods contain their own set of challenges (e.g., Bullock, Green, & Ha, 2010). We describe types of experimental manipulations targeting the mediator (manipulations demonstrating a causal effect of the mediator on the dependent variable and manipulations targeting the strength of the causal effect of the mediator) and types of experimental designs (double randomization, concurrent double randomization, and parallel), provide published examples of the designs, and discuss the strengths and challenges of each design. Therefore, the goals of this paper include providing a practical guide to manipulation-of-mediator designs in light of their challenges and encouraging researchers to use more rigorous approaches to mediation because manipulation-of-mediator designs strengthen the ability to infer causality of the mediating variable on the dependent variable.
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Experimental Investigation of a Point Design Optimized Arrow Wing HSCT Configuration
NASA Technical Reports Server (NTRS)
Narducci, Robert P.; Sundaram, P.; Agrawal, Shreekant; Cheung, S.; Arslan, A. E.; Martin, G. L.
1999-01-01
The M2.4-7A Arrow Wing HSCT configuration was optimized for straight and level cruise at a Mach number of 2.4 and a lift coefficient of 0.10. A quasi-Newton optimization scheme maximized the lift-to-drag ratio (by minimizing drag-to-lift) using Euler solutions from FL067 to estimate the lift and drag forces. A 1.675% wind-tunnel model of the Opt5 HSCT configuration was built to validate the design methodology. Experimental data gathered at the NASA Langley Unitary Plan Wind Tunnel (UPWT) section #2 facility verified CFL3D Euler and Navier-Stokes predictions of the Opt5 performance at the design point. In turn, CFL3D confirmed the improvement in the lift-to-drag ratio obtained during the optimization, thus validating the design procedure. A data base at off-design conditions was obtained during three wind-tunnel tests. The entry into NASA Langley UPWT section #2 obtained data at a free stream Mach number, M(sub infinity), of 2.55 as well as the design Mach number, M(sub infinity)=2.4. Data from a Mach number range of 1.8 to 2.4 was taken at UPWT section #1. Transonic and low supersonic Mach numbers, M(sub infinity)=0.6 to 1.2, was gathered at the NASA Langley 16 ft. Transonic Wind Tunnel (TWT). In addition to good agreement between CFD and experimental data, highlights from the wind-tunnel tests include a trip dot study suggesting a linear relationship between trip dot drag and Mach number, an aeroelastic study that measured the outboard wing deflection and twist, and a flap scheduling study that identifies the possibility of only one leading-edge and trailing-edge flap setting for transonic cruise and another for low supersonic acceleration.
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Clarke, Chris; Hill, Vivian; Charman, Tony
2017-12-01
Children with a diagnosis of autism are more likely to experience anxiety than their typically developing peers. Research suggests that Cognitive Behavioural Therapy (CBT) could offer a way to help children with autism manage their anxiety but most evidence is based on clinical trials. This study investigated a school-based CBT programme using a quasi-experimental design incorporating the child and parent versions of the Spence Children's Anxiety Scale (Spence, J Abnorm Psy 106(2):280-297, 1997) and the Coping Scale for Children and Youth (Brodzinsky et al., J Appl Dev Psychol 13:195-214, 1992). Interview data was incorporated to help understand the process of change further. Children in the experimental condition had lower levels of anxiety, maintained at follow-up and changes were found in coping behaviours such as lower behavioural avoidance strategies but increased problem solving strategies at follow-up. Limitations of the research together with future directions are also discussed.
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Kaya, Fadime; Buzlu, Sevim
2016-12-01
The research was conducted by a pretest and post-test conducted in a quasi-experimental design which aimed to determine effectiveness of Aggression Replacement Training (ART) on problem solving, anger and aggressive behaviour among adolescents with criminal attempts in Turkey. The study included 65 adolescents with criminal attempts (32 intervention, 33 control). There was no difference between the groups in terms of average age (16.13±1.10 in the experimental group and 16.21±0.89 in the control group). After the intervention, the experimental group showed significantly decreased Trait Anger levels (t=1.906; P=0.033), increased Anger Control scores (t=2.522; P=0.008), decreased Physical Aggression scores (t=1.925; P=0.031), decreased Hostility scores (t=2.496; P=0.009), increased Social Problem Solving total scores (t=2.937; P=0.005). Increased Anger Control scores were found to be significant when compared with the control group (t=2.273, P=0.026). These results showed that ART was effective on problem solving, anger and aggressive behaviour and can be used to develop positive behaviours among adolescents with criminal attempts. Copyright © 2016 Elsevier Inc. All rights reserved.
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Gaupp, Rainer; Körner, Mirjam; Fabry, Götz
2016-07-11
Patient safety (PS) is influenced by a set of factors on various levels of the healthcare system. Therefore, a systems-level approach and systems thinking is required to understand and improve PS. The use of e-learning may help to develop a systems thinking approach in medical students, as case studies featuring audiovisual media can be used to visualize systemic relationships in organizations. The goal of this quasi-experimental study was to determine if an e-learning can be utilized to improve systems thinking, knowledge, and attitudes towards PS. A quasi-experimental, longitudinal within- subjects design was employed. Participants were 321 third-year medical students who received online surveys before and after they participated in an e-learning course on PS. Primary outcome measures where levels of systems thinking and attitudes towards PS. Secondary outcome measures were the improvement of PS specific knowledge through the e-learning course. Levels of systems thinking showed significant improvement (58.72 vs. 61.27; p < .001) after the e-learning. Student's attitudes towards patient safety improved in several dimensions: After the course, students rated the influence of fatigue on safety higher (6.23 vs. 6.42, p < .01), considered patient empowerment more important (5.16 vs. 5.93, p < .001) and realized more often that human error is inevitable (5.75 vs. 5.97, p < .05). Knowledge on PS improved from 36.27 % correct answers before to 76.45 % after the e-learning (p < .001). Our results suggest that e-learning can be used to teach PS. Attitudes towards PS improved on several dimensions. Furthermore, we were able to demonstrate that a specifically designed e-learning program can foster the development of conceptual frameworks such as systems thinking, which facilitates the understanding of complex socio-technical systems within healthcare organisations.
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ERIC Educational Resources Information Center
Barnette, J. Jackson; Wallis, Anne Baber
2005-01-01
We rely a great deal on the schematic descriptions that represent experimental and quasi-experimental design arrangements, as well as the discussions of threats to validity associated with these, provided by Campbell and his associates: Stanley, Cook, and Shadish. Some of these designs include descriptions of treatments removed, removed and then…
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Schwanke, Natalí Lippert; Pohl, Hildegard Hedwig; Reuter, Cézane Priscila; Borges, Tássia Silvana; de Souza, Sonimar; Burgos, Miria Suzana
2016-04-01
Body posture and its components have been widely discussed, given the high prevalence of musculoskeletal disorders in children and adolescents. Among children and adolescents with overweight and obesity issues, these changes can be pronounced. This study sought to investigate whether a global exercise routine could result in positive changes in the angles and distances measured in postural assessments and in the number of abdominal and flexibility exercise repetitions performed by children and adolescents with overweight or obesity. A quasi-experimental design including an experimental group (EG) and a control group (CG) was used. The primary outcome variables included ratings of body posture (using SAPO software) and measures of abdominal muscle strength (number of sit-ups) and flexibility. The EG received an interdisciplinary intervention the included 48 sessions of global postural exercises performed three times a week. Of the 46 schoolchildren evaluated (EG, n = 23 and CG, n = 23), significant changes were observed in the EG from pre-to post-test in the thoracic angle (p = 0.001) and abdominal muscle strength (p = 0.016) for boys and in the thoracic angle (p = 0.010), abdominal muscle strength (p = 0.003) and flexibility (p = 0.010) for girls. Overall, the exercise program led to changes in the angle and distance measurements obtained in postural evaluations and contributed to increases in the number of repetitions of abdominal and flexibility exercises, indicating improvements in the EG group's body posture and health indicators. Copyright © 2015 Elsevier Ltd. All rights reserved.
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2017-06-30
description of a com- monly used material model that is modified in Chapter 5 based on the experimental data found in this work. 2.1 Background The quasi ...materials with varying levels of mi- crocracks. One of the intentions of this work is to establish experimental methods that can be applied to all quasi ...Projectile penetration into concrete target. To show how the experimental data obtained in this work can be used to improve quasi -brittle material
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Cummins, S.; Petticrew, M.; Higgins, C.; Findlay, A.; Sparks, L.
2005-01-01
Design: Prospective quasi-experimental design comparing baseline and follow up data in an "intervention" community with a matched "comparison" community in Glasgow, UK. Participants: 412 men and women aged 16 or over for whom follow up data on fruit and vegetable consumption and GHQ-12 were available. Main outcome measures: Fruit and vegetable consumption in portions per day, poor self reported health, and poor psychological health (GHQ-12). Main results: Adjusting for age, sex, educational attainment, and employment status there was no population impact on daily fruit and vegetable consumption, self reported, and psychological health. There was some evidence for a net reduction in the prevalence of poor psychological health for residents who directly engaged with the intervention. Conclusions: Government policy has advocated using large scale food retailing as a social intervention to improve diet and health in poor communities. In contrast with a previous uncontrolled study this study did not find evidence for a net intervention effect on fruit and vegetable consumption, although there was evidence for an improvement in psychological health for those who directly engaged with the intervention. Although definitive conclusions about the effect of large scale retailing on diet and health in deprived communities cannot be drawn from non-randomised controlled study designs, evaluations of the impacts of natural experiments may offer the best opportunity to generate evidence about the health impacts of retail interventions in poor communities. PMID:16286490
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Prashanth, N S; Elias, Maya Annie; Pati, Manoj Kumar; Aivalli, Praveenkumar; Munegowda, C M; Bhanuprakash, Srinath; Sadhana, S M; Criel, Bart; Bigdeli, Maryam; Devadasan, Narayanan
2016-08-22
India has the distinction of financing its healthcare mainly through out-of-pocket expenses by individual families contributing to catastrophic health expenditure and impoverishment. Nearly 70 % of the expenditure is on medicines purchased at private pharmacies. Patients with chronic ailments are especially affected, as they often need lifelong medicines. Over the past years in India, there have been several efforts to improve drug availability at government primary health centres. In this study, we aim to understand health system factors that affect utilisation and access to generic medicines for people with non-communicable diseases. This study aims to understand if (and how) a package of interventions targeting primary health centres and community participation platforms affect utilisation and access to generic medicines for people with non-communicable diseases in the current district context in India. This study will employ a quasi-experimental design and a qualitative theory-driven approach. PHCs will be randomly assigned to one of three arms of the intervention. In one arm, PHCs will receive inputs to optimise service delivery for non-communicable diseases, while the second arm will receive an additional package of interventions to strengthen community participation platforms for improving non-communicable disease care. The third arm will be the control. We will conduct household and facility surveys, before and after the intervention and will estimate the effect of the intervention by difference-in-difference analysis. Sample size for measuring effects was calculated based on obtaining at least 30 households for each primary health centre spread across three distance-based clusters. Primary outcomes include availability and utilisation of medicines at primary health centres and out-of-pocket expenditure for medicines by non-communicable disease households. Focus group discussions with patients and in-depth interviews with health workers will also be
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Optimizing Experimental Designs: Finding Hidden Treasure.
USDA-ARS?s Scientific Manuscript database
Classical experimental design theory, the predominant treatment in most textbooks, promotes the use of blocking designs for control of spatial variability in field studies and other situations in which there is significant variation among heterogeneity among experimental units. Many blocking design...
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Designing a placebo device: involving service users in clinical trial design.
Gooberman-Hill, Rachael; Jinks, Clare; Bouças, Sofia Barbosa; Hislop, Kelly; Dziedzic, Krysia S; Rhodes, Carol; Burston, Amanda; Adams, Jo
2013-12-01
Service users are increasingly involved in the design of clinical trials and in product and device development. Service user involvement in placebo development is crucial to a credible and acceptable placebo for clinical trials, but such involvement has not yet been reported. To enhance the design of a future clinical trial of hand splints for thumb-base osteoarthritis (OA), service users were involved in splint selection and design of a placebo splint. This article describes and reflects on this process. Two fora of service users were convened in 2011. Service users who had been prescribed a thumb splint for thumb-base OA were approached about involvement by Occupational Therapy (OT) practitioners. A total of eight service users took part in the fora. Service users discussed their experience of OA and their own splints and then tried a variety of alternative splints. Through this they identified the active features of splints alongside acceptable and unacceptable design features. Service users focused on wearability and support with or without immobilization. Fora discussed whether a placebo group ('arm') was an acceptable feature of a future trial, and service users developed a potential design for a placebo splint. This is the first project that to involve service users in placebo design. Service users are increasingly involved in product and device design and are ideally placed to identify features to make a placebo credible yet lacking key active ingredients. The future trial will include research into its acceptability. © 2013 John Wiley & Sons Ltd.
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Li, Yongfeng; Ma, Hua; Wang, Jiafu; Pang, Yongqiang; Zheng, Qiqi; Chen, Hongya; Han, Yajuan; Zhang, Jieqiu; Qu, Shaobo
2017-01-01
A high-efficiency tri-band quasi-continuous phase gradient metamaterial is designed and demonstrated based on spoof surface plasmon polaritons (SSPPs). High-efficiency polarizaiton conversion transmission is firstly achieved via tailoring phase differece between the transmisive SSPP and the space wave in orthogonal directions. As an example, a tri-band circular-to-circular (CTC) polarization conversion metamateiral (PCM) was designed by a nonlinearly dispersive phase difference. Using such PCM unit cell, a tri-band quasi-continuous phase gradient metamaterial (PGM) was then realized by virtue of the Pancharatnam-Berry phase. The distribution of the cross-polarization transmission phase along the x-direction is continuous except for two infinitely small intervals near the phases 0° and 360°, and thus the phase gradient has definition at any point along the x-direction. The simulated normalized polarization conversion transmission spectrums together with the electric field distributions for circularly polarized wave and linearly polarized wave demonstrated the high-efficiency anomalous refraction of the quasi-continuous PGM. The experimental verification for the linearly polarized incidence was also provided. PMID:28079185
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Biomechanics of the incudo-malleolar-joint - Experimental investigations for quasi-static loads.
Ihrle, S; Gerig, R; Dobrev, I; Röösli, C; Sim, J H; Huber, A M; Eiber, A
2016-10-01
Under large quasi-static loads, the incudo-malleolar joint (IMJ), connecting the malleus and the incus, is highly mobile. It can be classified as a mechanical filter decoupling large quasi-static motions while transferring small dynamic excitations. This is presumed to be due to the complex geometry of the joint inducing a spatial decoupling between the malleus and incus under large quasi-static loads. Spatial Laser Doppler Vibrometer (LDV) displacement measurements on isolated malleus-incus-complexes (MICs) were performed. With the malleus firmly attached to a probe holder, the incus was excited by applying quasi-static forces at different points. For each force application point the resulting displacement was measured subsequently at different points on the incus. The location of the force application point and the LDV measurement points were calculated in a post-processing step combining the position of the LDV points with geometric data of the MIC. The rigid body motion of the incus was then calculated from the multiple displacement measurements for each force application point. The contact regions of the articular surfaces for different load configurations were calculated by applying the reconstructed motion to the geometry model of the MIC and calculate the minimal distance of the articular surfaces. The reconstructed motion has a complex spatial characteristic and varies for different force application points. The motion changed with increasing load caused by the kinematic guidance of the articular surfaces of the joint. The IMJ permits a relative large rotation around the anterior-posterior axis through the joint when a force is applied at the lenticularis in lateral direction before impeding the motion. This is part of the decoupling of the malleus motion from the incus motion in case of large quasi-static loads. Copyright © 2015 Elsevier B.V. All rights reserved.
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Powell-Jackson, Timothy; Pereira, Shreya K; Dutt, Varun; Tougher, Sarah; Haldar, Kaveri; Kumar, Paresh
2016-08-01
Maternal depression is an important public health concern. We investigated whether a national-scale initiative that provides cash transfers to women giving birth in government health facilities, the Janani Suraksha Yojana (JSY), reduced maternal depression in India's largest state, Uttar Pradesh. Using primary data on 1695 women collected in early 2015, our quasi-experimental design exploited the fact that some women did not receive the JSY cash due to administrative problems in its disbursement - reasons that are unlikely to be correlated with determinants of maternal depression. We found that receipt of the cash was associated with an 8.5% reduction in the continuous measure of maternal depression and a 36% reduction in moderate depression. There was no evidence of an association with measures of emotional well-being, namely happiness and worry. The results suggest that the JSY had a clinically meaningful effect in reducing the burden of maternal depression, possibly by lessening the financial strain of delivery care. They contribute to the evidence that financial incentive schemes may have public health benefits beyond improving uptake of targeted health services. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.
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Patelarou, Athina; Melidoniotis, Evangelos; Sgouraki, Maria; Karatzi, Maria; Souvatzis, Xenia
2014-06-01
Surgical procedures pose stressful events for patients and their family members. The main purpose of this study was to determine if visiting patients in the postanesthesia care unit (PACU) would reduce the anxiety levels of Greek patients' family members. A prospective study with a one-group quasi-experimental pretest/post-test design was used. Situational anxiety of surgical patients' relatives was assessed using the state subscale of the State-Trait Anxiety Inventory (STAI; Greek validation) at the beginning of the surgical procedure and again after their visitation of patients in the PACU. STAI scores were significantly higher preoperatively (57 [23-80]) than postoperatively (51 [21-77]; P=.000008). Clinically significant levels of anxiety were present in 76% and 58% of the participants, pre- and postoperatively, respectively. Although postoperative STAI scores were reduced, family visitation in the PACU did not sufficiently reduce the anxiety of Greek family members to clinically acceptable levels. Copyright © 2014 American Society of PeriAnesthesia Nurses. Published by Elsevier Inc. All rights reserved.
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Characteristics of Quasi-Terminator Orbits Near Primitive Bodies
NASA Technical Reports Server (NTRS)
Broschart, Stephen B.; Lantoine, Gregory; Grebow, Daniel J.
2013-01-01
Quasi-terminator orbits are introduced as a class of quasi-periodic trajectories in the solar radiation pressure (SRP) perturbed Hill dynamics. These orbits offer significant displacements along the Sun-direction without the need for station-keeping maneuvers. Thus, quasi-terminator orbits have application to primitive-body missions, where a variety of observation geometries relative to the Sun (or other directions) can be achieved. This paper describes the characteristics of these orbits as a function of normalized SRP strength and invariant torus frequency ratio and presents a discussion of mission design considerations for a global surface mapping orbit design.
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Goudarzian, Amir Hossein; Nesami, Masoumeh Bagheri; Sedghi, Parisa; Gholami, Mahsan; Faraji, Maryam; Hatkehlouei, Mahdi Babaei
2018-01-20
This study aimed to determine the effect of self-care training on emotional intelligence of nursing students. This quasi-experimental study was conducted on nursing students of Mazandaran University of Medical Sciences in 2016. The subjects (60 students) that were collected with random sampling method were divided into experimental and control groups, and then, self-care behaviors were taught to the experimental group' students in 12 sessions by using a checklist. The subjects of control group were not taught. Emotional intelligence was measured by using Bradberry and Greaves' standard questionnaire before and after the intervention. Emotional intelligence scores of students in the experimental group showed positive and significant change between before (75.33 ± 7.23) and after (125.70 ± 7.79) of training (P < 0.001). Also t test shows a significant change in control (78.73 ± 6.54) and experimental groups (125.70 ± 7.79), after of training (P < 0.001). It is recommended that special programs be organized in order to improve the emotional intelligence of students that improve the likelihood of their success in life.
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Schwarzkopf, Daniel; Rüddel, Hendrik; Gründling, Matthias; Putensen, Christian; Reinhart, Konrad
2018-01-18
While sepsis-related mortality decreased substantially in other developed countries, mortality of severe sepsis remained as high as 44% in Germany. A recent German cluster randomized trial was not able to improve guideline adherence and decrease sepsis-related mortality within the participating hospitals, partly based on lacking support by hospital management and lacking resources for documentation of prospective data. Thus, more pragmatic approaches are needed to improve quality of sepsis care in Germany. The primary objective of the study is to decrease sepsis-related hospital mortality within a quality collaborative relying on claims data. The German Quality Network Sepsis (GQNS) is a quality collaborative involving 75 hospitals. This study protocol describes the conduction and evaluation of the start-up period of the GQNS running from March 2016 to August 2018. Democratic structures assure participatory action, a study coordination bureau provides central support and resources, and local interdisciplinary quality improvement teams implement changes within the participating hospitals. Quarterly quality reports focusing on risk-adjusted hospital mortality in cases with sepsis based on claims data are provided. Hospitals committed to publish their individual risk-adjusted mortality compared to the German average. A complex risk-model is used to control for differences in patient-related risk factors. Hospitals are encouraged to implement a bundle of interventions, e.g., interdisciplinary case analyses, external peer-reviews, hospital-wide staff education, and implementation of rapid response teams. The effectiveness of the GQNS is evaluated in a quasi-experimental difference-in-differences design by comparing the change of hospital mortality of cases with sepsis with organ dysfunction from a retrospective baseline period (January 2014 to December 2015) and the intervention period (April 2016 to March 2018) between the participating hospitals and all other German
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Peña-Purcell, Ninfa C; Boggess, May M; Jimenez, Natalia
2011-01-01
The purpose of this pilot study was to evaluate the effects of a culturally sensitive, empowerment-based diabetes self-management education program for Spanish-speaking Hispanic/Latinos. A prospective quasi-experimental repeated measures design tested the effectiveness of the ¡Si, Yo Puedo Controlar Mi Diabetes! diabetes self-management education program. In sum, 144 persons residing in 2 Texas counties at the Texas-Mexico border (Starr and Hidalgo) served as participants. Two groups were formed, an intervention and a control (wait list). Clinical (A1C), cognitive, attitudinal, behavioral, and cultural assessments were collected at baseline and 3 months. Demographic characteristics for the intervention and control groups were similar. Both groups were predominately female, low income, older than 40 years, and minimally acculturated. Baseline and posttest findings showed that the intervention group had a significant reduction in A1C values; median difference was 0.3 (n = 45), especially for those with higher baseline values. Participants in the intervention group also improved in their self-efficacy and self-care scores. Findings from the study suggest that additional dissemination of a diabetes self-management education program for Spanish-speaking Hispanic/Latinos is warranted to improve clinical outcomes and associated diabetes self-efficacy and self-care behaviors.
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Bohn-Goldbaum, Erika E; Phongsavan, Philayrath; Merom, Dafna; Rogers, Kris; Kamalesh, Venugopal; Bauman, Adrian E
2013-01-01
Outdoor recreational spaces have the potential to increase physical activity. This study used a quasi-experimental evaluation design to determine how a playground renovation impacts usage and physical activity of children and whether the visitations correlate with children's physical activity levels and parental impressions of the playground. Observational data and intercept interviews were collected simultaneously on park use and park-based activity among playground visitors at pre- and postrenovation at an intervention and a comparison park during three 2-hour periods each day over two weeks. No detectable difference in use between parks was observed at followup. In the intervention park, attendance increased among boys, but decreased among girls although this (nonsignificant) decline was less marked than in the comparison park. Following renovation, there was no detectable difference between parks in the number of children engaged in MVPA (interaction between park and time: P = 0.73). At the intervention park, there was a significant decline in girls engaging in MVPA at followup (P = 0.04). Usage was correlated with parental/carer perceptions of playground features but not with physical activity levels. Renovations have limited the potential to increase physical activity until factors influencing usage and physical activity behavior are better understood.
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Choi, Mona; Lee, HyeongSuk; Park, Joon Ho
2018-02-01
The academic electronic medical record (AEMR) system is applied with the expectation that nursing students will be able to attain competence in healthcare decision-making and nursing informatics competencies. However, there is insufficient evidence regarding the advantage of applying mobile devices to clinical practicum. This study aimed to examine the effect of an experiment that introduced a mobile AEMR application for undergraduate nursing students in their practicum. A quasi-experimental design was used. The subjects were 75 third-year nursing students enrolled in clinical practicum and were divided into an experimental (practicum with AEMR) and a control (conventional practicum) group. Nursing informatics competencies, critical thinking disposition, and satisfaction with clinical practicum were measured before and after the clinical practicum for each group. The usability of the AEMR application was also examined for the experimental group after the experiment. After the experiment, the experimental group showed a significant increase in the informatics knowledge domain of nursing informatics competencies in the post-test. The difference in critical thinking between the experimental and control groups was not statistically significant. Regarding satisfaction with the clinical practicum, the experimental group exhibited a significantly higher level of satisfaction in "preparation of a diagnostic test or laboratory test and understanding of the results" and "nursing intervention and documentation" than the control group. Students who participated in the practicum using the AEMR application considered it useful. The AEMR application was an effective educational method for practicing the immediate documentation of students' observations and interventions and was available at the patients' bedsides. To improve critical thinking, it is necessary to apply a variety of approaches when solving clinical problems. Copyright © 2017 Elsevier Ltd. All rights reserved.
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Why crying does and sometimes does not seem to alleviate mood: a quasi-experimental study.
Gračanin, Asmir; Vingerhoets, Ad J J M; Kardum, Igor; Zupčić, Marina; Šantek, Maja; Šimić, Mia
Whereas retrospective studies suggest that crying can be beneficial in terms of mood enhancement, results of quasi-experimental laboratory studies consistently demonstrate its negative effects on mood. The present study was specifically designed to evaluate a parsimonious explanation for this paradox by assessing mood after crying in a laboratory, both immediately and at follow up. Mood ratings of 28 objectively established criers and 32 non-criers were compared before and immediately after the exposure to an emotional movie, as well as 20 and 90 min later. As expected, immediately after the film, negative mood significantly increased in criers, while it did not change in non-criers. This mood deterioration was followed by a recovery that resulted in return to the baseline mood levels at the third measurement. Criers subsequently reported mood enhancements at the final measurement compared to the pre-film measurement. Crying frequency did not predict mood changes above those predicted by the presence of crying. The observed relation between crying and more long-term mood recovery reconciles seemingly contrasting earlier results and provides a simple and obvious explanation. After the initial deterioration of mood following crying that was observed in laboratory studies, it apparently takes some time for the mood, not just to recover, but also to become even less negative than before the emotional event, which corresponds to the results of retrospective studies.
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The Experimental Design Ability Test (EDAT)
ERIC Educational Resources Information Center
Sirum, Karen; Humburg, Jennifer
2011-01-01
Higher education goals include helping students develop evidence based reasoning skills; therefore, scientific thinking skills such as those required to understand the design of a basic experiment are important. The Experimental Design Ability Test (EDAT) measures students' understanding of the criteria for good experimental design through their…
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Estimation of Quasi-Stiffness and Propulsive Work of the Human Ankle in the Stance Phase of Walking
Shamaei, Kamran; Sawicki, Gregory S.; Dollar, Aaron M.
2013-01-01
Characterizing the quasi-stiffness and work of lower extremity joints is critical for evaluating human locomotion and designing assistive devices such as prostheses and orthoses intended to emulate the biological behavior of human legs. This work aims to establish statistical models that allow us to predict the ankle quasi-stiffness and net mechanical work for adults walking on level ground. During the stance phase of walking, the ankle joint propels the body through three distinctive phases of nearly constant stiffness known as the quasi-stiffness of each phase. Using a generic equation for the ankle moment obtained through an inverse dynamics analysis, we identify key independent parameters needed to predict ankle quasi-stiffness and propulsive work and also the functional form of each correlation. These parameters include gait speed, ankle excursion, and subject height and weight. Based on the identified form of the correlation and key variables, we applied linear regression on experimental walking data for 216 gait trials across 26 subjects (speeds from 0.75–2.63 m/s) to obtain statistical models of varying complexity. The most general forms of the statistical models include all the key parameters and have an R2 of 75% to 81% in the prediction of the ankle quasi-stiffnesses and propulsive work. The most specific models include only subject height and weight and could predict the ankle quasi-stiffnesses and work for optimal walking speed with average error of 13% to 30%. We discuss how these models provide a useful framework and foundation for designing subject- and gait-specific prosthetic and exoskeletal devices designed to emulate biological ankle function during level ground walking. PMID:23555839
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Controlled experiments for dense gas diffusion: Experimental design and execution, model comparison
DOE Office of Scientific and Technical Information (OSTI.GOV)
Egami, R.; Bowen, J.; Coulombe, W.
1995-07-01
An experimental baseline CO2 release experiment at the DOE Spill Test Facility on the Nevada Test Site in Southern Nevada is described. This experiment was unique in its use of CO2 as a surrogate gas representative of a variety of specific chemicals. Introductory discussion places the experiment in historical perspective. CO2 was selected as a surrogate gas to provide a data base suitable for evaluation of model scenarios involving a variety of specific dense gases. The experiment design and setup are described, including design rationale and quality assurance methods employed. Resulting experimental data are summarized. Data usefulness is examined throughmore » a preliminary comparison of experimental results with simulations performed using the SLAV and DEGADIS dense gas models.« less
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Charbonneau-Lefort, Mathieu; Afeyan, Bedros; Fejer, M. M.
Chirped quasi-phase-matched optical parametric amplifiers (chirped QPM OPAs) are investigated experimentally. The measured collinear gain is constant over a broad bandwidth, which makes these devices attractive candidates for use in femtosecond amplifier systems. The experiment also shows that chirped QPM OPAs support noncollinear gain-guided modes. These modes can dominate the desired collinear gain and generate intense parametric fluorescence. Finally, design guidelines to mitigate these parasitic processes are discussed.
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Nguyen, Ly Thuy; Alexander, Kimberly; Yates, Patsy
2018-06-01
To assess the feasibility of conducting a trial of a psychoeducational intervention involving the provision of tailored information and coaching to improve management of a cancer-related symptom cluster (fatigue, pain, and sleep disturbance) and reduce symptom cluster impacts on patient health outcomes in the Vietnamese context and to undertake a preliminary evaluation of the intervention. A parallel-group single-blind pilot quasi-experimental trial was conducted with 102 cancer patients in one Vietnamese hospital. The intervention group received one face-to-face session and two phone sessions delivered by a nurse one week apart, and the comparison group received usual care. Patient outcomes were measured at baseline before the chemotherapy cycle and immediately preceding the next chemotherapy cycle. Separate linear mixed models were used to evaluate the impact of the intervention on total symptom cluster severity, symptom scores, functional status, depressive symptoms, and health-related quality of life. The study design was feasible with a recruitment rate of 22.6% and attrition rate of 9.8%. Compared to the control group, the intervention group showed a significant reduction in symptom cluster severity, fatigue severity, fatigue interference, sleep disturbance, depression, and anxiety. Significant differences were not observed for pain severity, pain interference, functional status, and health-related quality of life. The intervention was acceptable to the study population, with a high attendance rate of 78% and adherence rate of 95.7%. On the basis of the present study findings, future randomized controlled trials are needed to test the effectiveness of a symptom cluster psychoeducational intervention in Vietnam. Copyright © 2018 American Academy of Hospice and Palliative Medicine. Published by Elsevier Inc. All rights reserved.
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ERIC Educational Resources Information Center
Hantla, Bryce F.
2014-01-01
This quasi-experimental, mixed methods study analyzes the effects of the flipped classroom on the variables of a critical thinking rubric used by a Christian liberal arts college and compares these results with those of the California Critical Thinking Skills Test (CCTST). Second, this dissertation examines the effects of the flipped classroom on…
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Learning Effects of an Experimental EFL Program in Second Life
ERIC Educational Resources Information Center
Wang, Charles Xiaoxue; Calandra, Brendan; Hibbard, Susan T.; McDowell Lefaiver, Mary L.
2012-01-01
This paper reports on the effects an experimental English as a Foreign Language (EFL) program in Second Life (SL) had on Chinese student EFL learning. The study took an evaluative approach using quasi-experimental design with participants from one Chinese university and one American university in the southeastern United States. Results indicated…
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Quasi-Particle Self-Consistent GW for Molecules.
Kaplan, F; Harding, M E; Seiler, C; Weigend, F; Evers, F; van Setten, M J
2016-06-14
We present the formalism and implementation of quasi-particle self-consistent GW (qsGW) and eigenvalue only quasi-particle self-consistent GW (evGW) adapted to standard quantum chemistry packages. Our implementation is benchmarked against high-level quantum chemistry computations (coupled-cluster theory) and experimental results using a representative set of molecules. Furthermore, we compare the qsGW approach for five molecules relevant for organic photovoltaics to self-consistent GW results (scGW) and analyze the effects of the self-consistency on the ground state density by comparing calculated dipole moments to their experimental values. We show that qsGW makes a significant improvement over conventional G0W0 and that partially self-consistent flavors (in particular evGW) can be excellent alternatives.
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NASA Astrophysics Data System (ADS)
Butchart, Neal; Anstey, James A.; Hamilton, Kevin; Osprey, Scott; McLandress, Charles; Bushell, Andrew C.; Kawatani, Yoshio; Kim, Young-Ha; Lott, Francois; Scinocca, John; Stockdale, Timothy N.; Andrews, Martin; Bellprat, Omar; Braesicke, Peter; Cagnazzo, Chiara; Chen, Chih-Chieh; Chun, Hye-Yeong; Dobrynin, Mikhail; Garcia, Rolando R.; Garcia-Serrano, Javier; Gray, Lesley J.; Holt, Laura; Kerzenmacher, Tobias; Naoe, Hiroaki; Pohlmann, Holger; Richter, Jadwiga H.; Scaife, Adam A.; Schenzinger, Verena; Serva, Federico; Versick, Stefan; Watanabe, Shingo; Yoshida, Kohei; Yukimoto, Seiji
2018-03-01
The Stratosphere-troposphere Processes And their Role in Climate (SPARC) Quasi-Biennial Oscillation initiative (QBOi) aims to improve the fidelity of tropical stratospheric variability in general circulation and Earth system models by conducting coordinated numerical experiments and analysis. In the equatorial stratosphere, the QBO is the most conspicuous mode of variability. Five coordinated experiments have therefore been designed to (i) evaluate and compare the verisimilitude of modelled QBOs under present-day conditions, (ii) identify robustness (or alternatively the spread and uncertainty) in the simulated QBO response to commonly imposed changes in model climate forcings (e.g. a doubling of CO2 amounts), and (iii) examine model dependence of QBO predictability. This paper documents these experiments and the recommended output diagnostics. The rationale behind the experimental design and choice of diagnostics is presented. To facilitate scientific interpretation of the results in other planned QBOi studies, consistent descriptions of the models performing each experiment set are given, with those aspects particularly relevant for simulating the QBO tabulated for easy comparison.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Charbonneau-Lefort, Mathieu; Afeyan, Bedros; Fejer, M. M.
Optical parametric amplifiers using chirped quasi-phase-matching (QPM) gratings offer the possibility of engineering the gain and group delay spectra. We give practical formulas for the design of such amplifiers. We consider linearly chirped QPM gratings providing constant gain over a broad bandwidth, sinusoidally modulated profiles for selective frequency amplification and a pair of QPM gratings working in tandem to ensure constant gain and constant group delay at the same time across the spectrum. Finally, the analysis is carried out in the frequency domain using Wentzel–Kramers–Brillouin analysis.
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Physical activity loyalty cards for behavior change: a quasi-experimental study.
Hunter, Ruth F; Tully, Mark A; Davis, Michael; Stevenson, Michael; Kee, Frank
2013-07-01
Financial incentives have been advocated by the UK and U.S. governments to encourage adoption of healthy lifestyles. However, evidence to support the use of incentives for changing physical activity (PA) behavior is sparse. To investigate the effectiveness of financial incentives to increase PA in adults in the workplace. Two-arm quasi-experimental design. Employees (n=406) in a workplace setting in Belfast, Northern Ireland, UK. Using a loyalty card to collect points and earn rewards, participants (n=199) in the Incentive Group monitored their PA levels and received financial incentives (retail vouchers) for minutes of PA completed over the course of a 12-week intervention period. Participants (n=207) in the comparison group used their loyalty card to self-monitor their PA levels but were not able to earn points or obtain incentives (No Incentive Group). The primary outcome was minutes of PA objectively measured using a novel PA tracking system at baseline (April 2011); Week 6 (June 2011); and Week 12 (July 2011). Other outcomes, including a self-report measure of PA, were collected at baseline, Week 12, and 6 months (October 2011). Data were analyzed in June 2012. No significant differences between groups were found for primary or secondary outcomes at the 12-week and 6-month assessments. Participants in the Incentive Group recorded 17.52 minutes of PA/week (95% CI=12.49, 22.56) compared to 16.63 minutes/week (95% CI=11.76, 21.51) in the No Incentive Group at Week 12 (p=0.59). At 6 months, participants in the Incentive Group recorded 26.18 minutes of PA/week (95% CI=20.06, 32.29) compared to 24.00 minutes/week (95% CI=17.45, 30.54) in the No Incentive Group (p=0.45). Financial incentives did not encourage participants to undertake more PA than self-monitoring PA. This study contributes to the evidence base and has important implications for increasing participation in physical activity and fostering links with the business sector. Copyright © 2013 American
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Quasi-Airy beams along tunable propagation trajectories and directions.
Qian, Yixian; Zhang, Site
2016-05-02
We present a theoretical and experimental exhibit that accelerates quasi-Airy beams propagating along arbitrarily appointed parabolic trajectories and directions in free space. We also demonstrate that such quasi-Airy beams can be generated by a tunable phase pattern, where two disturbance factors are introduced. The topological structures of quasi-Airy beams are readily manipulated with tunable phase patterns. Quasi-Airy beams still possess the characteristics of non-diffraction, self-healing to some extent, although they are not the solutions for paraxial wave equation. The experiments show the results are consistent with theoretical predictions. It is believed that the property of propagation along arbitrarily desired parabolic trajectories will provide a broad application in trapping atom and living cell manipulation.
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Lee, Kyung Eun
2018-04-01
An important goal of nursing education is helping students achieve core competencies efficiently. One proposed way of improving nursing education is team-based learning (TBL). The aim of this study was to assess the comparative effectiveness of TBL and lecture-style classes in terms of teaching core competencies in nursing education, which include clinical competence skills, problem-solving ability, communication competencies, critical thinking ability, and self-leadership. This quasi-experimental study enrolled 183 students as participants, with 95 and 88 in the experimental and control groups, respectively. These two groups attended 6 hours (2 hours weekly for 3 weeks) of TBL and lecture-style classes, respectively. Differences in core competencies between the two groups were compared before and after the intervention. The experimental group achieved significantly higher scores for clinical competence skills, communication competence, critical thinking ability, and self-leadership at posttest than at pretest, whereas the control group achieved significantly higher scores for clinical competence skills and critical thinking ability at posttest than at pretest. After the intervention, the experimental group had significantly better clinical competence skills, communication competence, and self-leadership than the control group. TBL is an effective approach method to teaching core competencies in nursing education.
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ERIC Educational Resources Information Center
Katsioloudis, Petros; Jovanovic, Vukica; Jones, Mildred
2016-01-01
Several theorists believe that different types of visual cues influence cognition and behavior through learned associations; however, research provides inconsistent results. Considering this, a quasi-experimental study was done to determine if there are significant positive effects of visual cues (color blue) and to identify if a positive increase…
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Optimal Experimental Design for Model Discrimination
Myung, Jay I.; Pitt, Mark A.
2009-01-01
Models of a psychological process can be difficult to discriminate experimentally because it is not easy to determine the values of the critical design variables (e.g., presentation schedule, stimulus structure) that will be most informative in differentiating them. Recent developments in sampling-based search methods in statistics make it possible to determine these values, and thereby identify an optimal experimental design. After describing the method, it is demonstrated in two content areas in cognitive psychology in which models are highly competitive: retention (i.e., forgetting) and categorization. The optimal design is compared with the quality of designs used in the literature. The findings demonstrate that design optimization has the potential to increase the informativeness of the experimental method. PMID:19618983
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Photoproduction of Mesons on Quasi-Free Nucleons
NASA Astrophysics Data System (ADS)
Keshelashvili, I.
2014-11-01
The investigation of excited baryon states is important to understand the underling nature/symmetries of hadronic matter. Historically, the first nucleon excitation experiments have been done using charged pion and kaon secondary beams. Later the antiproton-proton scattering has also been involved. However, since the beginning of the 90's meson photoproduction reactions have been considered as a powerful tool in baryon spectroscopy. In this contribution, we overview our experimental programs conducted at the bremsstrahlung photon beams of the MAMI accelerator in Mainz and the ELSA accelerator in Bonn. The results are differential and total cross sections for photoproduction of light neutral mesons and of meson pairs off quasi-free nucleons bound in the deuteron (and sometimes other light nuclei). The scientific programs of this experiments also include single and double polarization measurements as well.
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An experimental study of a quasi-two dimensional rising foam
NASA Astrophysics Data System (ADS)
Bennani, Nora; Fujiwara, Akiko; Takagi, Shu; Matsumoto, Yoichiro
2006-11-01
Motivated by the use of the flotation process to clean a non-homogeneous liquid, we here report on an experimental study of quasi-two dimensional flowing foam. Conditions are free-drainage which is driven by gravity and capillarity. The coarsening process, which is due to the aging of the foam, is also occurring, changing the general shape of this polydispersed foam cells. Tea seed saponin was used as surfactant, and Rhodamine-B fluorescent particles were tracked using the Particle Tracking Velocimetry technique. Experiments were performed in an acrylic tank filled with tap water (height H= 1m, width W= 0.15 m and Depth D= 8mm). The air was injected from its bottom part with a fixed flow rate, and went through a porous plate (size of the pores was 10μm), and created 3mm diameter non-spherical bubbles. The void fraction, in the liquid phase, was estimated to be around 1%. Fluorescent particles were beforehand added in the liquid phase in order to trace wastewater particle motion. The generated foam gas cells sizes were in the range of 0.5 to 5 cm, depending on the surfactant concentration and the coarsening process. The behaviours of these particle tracers and of the liquid, with these herein foaming conditions, are here presented and are compared to available data and theories.
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S Potash, Jordan; Hy Ho, Andy; Chan, Faye; Lu Wang, Xiao; Cheng, Carol
2014-05-01
The need for empathy and the difficulties of coping with mortality when caring for the dying and the bereaved can cause psychological, emotional, and spiritual strain. The aim of this study was to examine the effectiveness of art-therapy-based supervision in reducing burnout and death anxiety among end-of-life care workers in Hong Kong. Through a quasi-experimental design, 69 participants enrolled in a 6-week, 18-hour art-therapy-based supervision group, and another 63 enrolled in a 3-day, 18-hour standard skills-based supervision group (n=132). Pre- and post-intervention assessments were carried out with three outcome measures: the Maslach Burnout Inventory-General Survey, the Five Facet Mindfulness Questionnaire, and the Death Attitude Profile-Revised. The data was analysed using paired sample t-tests. Significant reductions in exhaustion and death anxiety and significant increases in emotional awareness were observed for participants in the art-therapy-based supervision group. This study provides preliminary evidence that art-therapy-based supervision for end-of-life care workers can reduce burnout by enhancing emotional awareness and regulation, fostering meaning-making, and promoting reflection on death.
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Lai, Eliza S. Y.; Kwok, Chi-Leung; Wong, Paul W. C.; Fu, King-Wa; Law, Yik-Wa; Yip, Paul S. F.
2016-01-01
Background A pilot study about the effectiveness of a universal school-based programme, “The Little Prince is Depressed”, for preventing depression in Chinese adolescents in Hong Kong was conducted and reported previously. This study used a larger sample to examine the effectiveness and sustainability of the programme. Methods This study used quasi-experimental design. Twelve schools enrolled in “The Little Prince is Depressed” programme either as an intervention or a control condition. The intervention schools carried out the 12-session programme in two phases: the professional-led first phase and the teacher-led second phase. All participants were required to complete a questionnaire at three time points measuring their (1) depressive, anxiety, and stress levels; (2) knowledge of mental health; (3) attitudes towards mental illness; (4) perceived social support; and (5) help-seeking behaviours. Results A total of 3,391 students participated in the study. The level of depressive symptoms did not reduce significantly at post-intervention; however, a delayed effect was observed at follow-up assessment for the participants of the teacher-led group in reducing anxiety and stress levels. Also, the knowledge of mental health and attitudes towards mental illness of the intervention-group participants significantly improved at post-test, and the outcomes were maintained at 4 to 5 months after the intervention in both the professional-led and the teacher-led conditions (p<.05). A preference among schoolchildren for whom to seek help from was identified. Conclusions The universal depression prevention programme was effective in enhancing knowledge of mental health and promoting a more positive attitude towards mental illness among adolescents in Hong Kong. In particular, the teacher-led group showed better outcomes than the professional-led group in reducing students’ anxiety and stress at follow-up period. The programme can achieve sustainability in schools if
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Lai, Eliza S Y; Kwok, Chi-Leung; Wong, Paul W C; Fu, King-Wa; Law, Yik-Wa; Yip, Paul S F
2016-01-01
A pilot study about the effectiveness of a universal school-based programme, "The Little Prince is Depressed", for preventing depression in Chinese adolescents in Hong Kong was conducted and reported previously. This study used a larger sample to examine the effectiveness and sustainability of the programme. This study used quasi-experimental design. Twelve schools enrolled in "The Little Prince is Depressed" programme either as an intervention or a control condition. The intervention schools carried out the 12-session programme in two phases: the professional-led first phase and the teacher-led second phase. All participants were required to complete a questionnaire at three time points measuring their (1) depressive, anxiety, and stress levels; (2) knowledge of mental health; (3) attitudes towards mental illness; (4) perceived social support; and (5) help-seeking behaviours. A total of 3,391 students participated in the study. The level of depressive symptoms did not reduce significantly at post-intervention; however, a delayed effect was observed at follow-up assessment for the participants of the teacher-led group in reducing anxiety and stress levels. Also, the knowledge of mental health and attitudes towards mental illness of the intervention-group participants significantly improved at post-test, and the outcomes were maintained at 4 to 5 months after the intervention in both the professional-led and the teacher-led conditions (p<.05). A preference among schoolchildren for whom to seek help from was identified. The universal depression prevention programme was effective in enhancing knowledge of mental health and promoting a more positive attitude towards mental illness among adolescents in Hong Kong. In particular, the teacher-led group showed better outcomes than the professional-led group in reducing students' anxiety and stress at follow-up period. The programme can achieve sustainability in schools if teachers are provided with adequate support.
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Newspapers in Science Education: A Study Involving Sixth Grade Students
ERIC Educational Resources Information Center
Lai, Ching-San; Wang, Yun-Fei
2016-01-01
The purpose of this study was to explore the learning performance of sixth grade elementary school students using newspapers in science teaching. A quasi-experimental design with a single group was used in this study. Thirty-three sixth grade elementary school students participated in this study. The research instruments consisted of three…
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Taylor, Lisa; Poland, Fiona; Harrison, Peter; Stephenson, Richard
2011-01-01
To evaluate a systematic treatment programme developed by the researcher that targeted aspects of visual functioning affected by visual field deficits following stroke. The study design was a non-equivalent control (conventional) group pretest-posttest quasi-experimental feasibility design, using multisite data collection methods at specified stages. The study was undertaken within three acute hospital settings as outpatient follow-up sessions. Individuals who had visual field deficits three months post stroke were studied. A treatment group received routine occupational therapy and an experimental group received, in addition, a systematic treatment programme. The treatment phase of both groups lasted six weeks. The Nottingham Adjustment Scale, a measure developed specifically for visual impairment, was used as the primary outcome measure. The change in Nottingham Adjustment Scale score was compared between the experimental (n = 7) and conventional (n = 8) treatment groups using the Wilcoxon signed ranks test. The result of Z = -2.028 (P = 0.043) showed that there was a statistically significant difference between the change in Nottingham Adjustment Scale score between both groups. The introduction of the systematic treatment programme resulted in a statistically significant change in the scores of the Nottingham Adjustment Scale.
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Lapchuk, A; Pashkevich, G A; Prygun, O V; Yurlov, V; Borodin, Y; Kryuchyn, A; Korchovyi, A A; Shylo, S
2015-10-01
The quasi-spiral 2D diffractive optical element (DOE) based on M-sequence of length N=15 is designed and manufactured. The speckle suppression efficiency by the DOE rotation is measured. The speckle suppression coefficients of 10.5, 6, and 4 are obtained for green, violet, and red laser beams, respectively. The results of numerical simulation and experimental data show that the quasi-spiral binary DOE structure can be as effective in speckle reduction as a periodic 2D DOE structure. The numerical simulation and experimental results show that the speckle suppression efficiency of the 2D DOE structure decreases approximately twice at the boundaries of the visible range. It is shown that a replacement of this structure with the bilateral 1D DOE allows obtaining the maximum speckle suppression efficiency in the entire visible range of light.
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Selecting Models for Measuring Change When True Experimental Conditions Do Not Exist.
ERIC Educational Resources Information Center
Fortune, Jim C.; Hutson, Barbara A.
1984-01-01
Measuring change when true experimental conditions do not exist is a difficult process. This article reviews the artifacts of change measurement in evaluations and quasi-experimental designs, delineates considerations in choosing a model to measure change under nonideal conditions, and suggests ways to organize models to facilitate selection.…
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Quasi-multi-pulse voltage source converter design with two control degrees of freedom
NASA Astrophysics Data System (ADS)
Vural, A. M.; Bayindir, K. C.
2015-05-01
In this article, the design details of a quasi-multi-pulse voltage source converter (VSC) switched at line frequency of 50 Hz are given in a step-by-step process. The proposed converter is comprised of four 12-pulse converter units, which is suitable for the simulation of single-/multi-converter flexible alternating current transmission system devices as well as high voltage direct current systems operating at the transmission level. The magnetic interface of the converter is originally designed with given all parameters for 100 MVA operation. The so-called two-angle control method is adopted to control the voltage magnitude and the phase angle of the converter independently. PSCAD simulation results verify both four-quadrant converter operation and closed-loop control of the converter operated as static synchronous compensator (STATCOM).
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D-OPTIMAL EXPERIMENTAL DESIGNS TO TEST FOR DEPARTURE FROM ADDITIVITY IN A FIXED-RATIO MIXTURE RAY.
Traditional factorial designs for evaluating interactions among chemicals in a mixture are prohibitive when the number of chemicals is large. However, recent advances in statistically-based experimental design have made it easier to evaluate interactions involving many chemicals...
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Richmond, Melissa K; Pampel, Fred C; Wood, Randi C; Nunes, Ana P
2017-04-01
Employee Assistance Programs (EAPs) are widely used to help employees experiencing personal or work-related difficulties that impact work productivity. However, rigorous research on the effectiveness of programs to improve work-related outcomes is lacking. The current study represents a major advance in EAP research by using a prospective, quasi-experimental design with a large and diverse employee base. Using propensity scores calculated from demographic, social, work-related, and psychological variables collected on baseline surveys, we matched 156 employees receiving EAP to 188 non-EAP employees. Follow-up surveys were collected from 2 to 12 months post-baseline (M = 6.0). At follow-up, EAP employees had significantly greater reductions in absenteeism (b = -.596, p = .001) and presenteeism (b = -.217, p = .038), but not workplace distress (b = -.079, p = .448), than did non-EAP employees. Tests of moderation of baseline alcohol use, depression, anxiety, and productivity indicate that for the most part, the program works equally well for all groups. However, EAP did more to reduce absenteeism for those who began with lower severity of depression and anxiety at baseline. Results provide the scientific rigor needed to demonstrate EAP impact on improved work outcomes. In the first study of its kind, findings confirm the value of EAPs to help employees address personal and work-related concerns that are affecting job performance. (PsycINFO Database Record (c) 2017 APA, all rights reserved).
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Enhancing public involvement in assistive technology design research.
Williamson, Tracey; Kenney, Laurence; Barker, Anthony T; Cooper, Glen; Good, Tim; Healey, Jamie; Heller, Ben; Howard, David; Matthews, Martin; Prenton, Sarah; Ryan, Julia; Smith, Christine
2015-05-01
To appraise the application of accepted good practice guidance on public involvement in assistive technology research and to identify its impact on the research team, the public, device and trial design. Critical reflection and within-project evaluation were undertaken in a case study of the development of a functional electrical stimulation device. Individual and group interviews were undertaken with lay members of a 10 strong study user advisory group and also research team members. Public involvement was seen positively by research team members, who reported a positive impact on device and study designs. The public identified positive impact on confidence, skills, self-esteem, enjoyment, contribution to improving the care of others and opportunities for further involvement in research. A negative impact concerned the challenge of engaging the public in dissemination after the study end. The public were able to impact significantly on the design of an assistive technology device which was made more fit for purpose. Research team attitudes to public involvement were more positive after having witnessed its potential first hand. Within-project evaluation underpins this case study which presents a much needed detailed account of public involvement in assistive technology design research to add to the existing weak evidence base. The evidence base for impact of public involvement in rehabilitation technology design is in need of development. Public involvement in co-design of rehabilitation devices can lead to technologies that are fit for purpose. Rehabilitation researchers need to consider the merits of active public involvement in research.
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Exploring biological interaction networks with tailored weighted quasi-bicliques
2012-01-01
Background Biological networks provide fundamental insights into the functional characterization of genes and their products, the characterization of DNA-protein interactions, the identification of regulatory mechanisms, and other biological tasks. Due to the experimental and biological complexity, their computational exploitation faces many algorithmic challenges. Results We introduce novel weighted quasi-biclique problems to identify functional modules in biological networks when represented by bipartite graphs. In difference to previous quasi-biclique problems, we include biological interaction levels by using edge-weighted quasi-bicliques. While we prove that our problems are NP-hard, we also describe IP formulations to compute exact solutions for moderately sized networks. Conclusions We verify the effectiveness of our IP solutions using both simulation and empirical data. The simulation shows high quasi-biclique recall rates, and the empirical data corroborate the abilities of our weighted quasi-bicliques in extracting features and recovering missing interactions from biological networks. PMID:22759421
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Goodnight, Jackson A.; Lahey, Benjamin B.; Van Hulle, Carol A.; Rodgers, Joseph L.; Rathouz, Paul J.; Waldman, Irwin D.; D’Onofrio, Brian M.
2012-01-01
A quasi-experimental comparison of cousins differentially exposed to levels of neighborhood disadvantage (ND) was used with extensive measured covariates to test the hypothesis that neighborhood risk has independent effects on youth conduct problems (CPs). Multilevel analyses were based on mother-rated ND and both mother-reported CPs across 4–13 years (n = 7,077) and youth-reported CPs across 10–13 years (n = 4,524) from the Children of the National Longitudinal Survey of Youth. ND was robustly related to CPs reported by both informants when controlling for both measured risk factors that are correlated with ND and unmeasured confounds. These findings are consistent with the hypothesis that ND has influence on conduct problems. PMID:21942334
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Relation between experimental and non-experimental study designs. HB vaccines: a case study
Jefferson, T.; Demicheli, V.
1999-01-01
STUDY OBJECTIVE: To examine the relation between experimental and non- experimental study design in vaccinology. DESIGN: Assessment of each study design's capability of testing four aspects of vaccine performance, namely immunogenicity (the capacity to stimulate the immune system), duration of immunity conferred, incidence and seriousness of side effects, and number of infections prevented by vaccination. SETTING: Experimental and non-experimental studies on hepatitis B (HB) vaccines in the Cochrane Vaccines Field Database. RESULTS: Experimental and non-experimental vaccine study designs are frequently complementary but some aspects of vaccine quality can only be assessed by one of the types of study. More work needs to be done on the relation between study quality and its significance in terms of effect size. PMID:10326054
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Vu-Bac, N.; Bessa, M. A.; Rabczuk, Timon; ...
2015-09-10
In this paper, we present experimentally validated molecular dynamics predictions of the quasi- static yield and post-yield behavior for a highly cross-linked epoxy polymer under gen- eral stress states and for different temperatures. In addition, a hierarchical multiscale model is presented where the nano-scale simulations obtained from molecular dynamics were homogenized to a continuum thermoplastic constitutive model for the epoxy that can be used to describe the macroscopic behavior of the material. Three major conclusions were achieved: (1) the yield surfaces generated from the nano-scale model for different temperatures agree well with the paraboloid yield crite- rion, supporting previous macroscopicmore » experimental observations; (2) rescaling of the entire yield surfaces to the quasi-static case is possible by considering Argon’s theoretical predictions for pure compression of the polymer at absolute zero temperature; (3) nano- scale simulations can be used for an experimentally-free calibration of macroscopic con- tinuum models, opening new avenues for the design of materials and structures through multi-scale simulations that provide structure-property-performance relationships.« less
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ERIC Educational Resources Information Center
Shobo, Yetty; Wong, Jen D.; Bell, Angie
2014-01-01
Regression discontinuity (RD), an "as good as randomized," research design is increasingly prominent in education research in recent years; the design gets eligible quasi-experimental designs as close as possible to experimental designs by using a stated threshold on a continuous baseline variable to assign individuals to a…
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High School Student Information Access and Engineering Design Performance
ERIC Educational Resources Information Center
Mentzer, Nathan
2014-01-01
Developing solutions to engineering design problems requires access to information. Research has shown that appropriately accessing and using information in the design process improves solution quality. This quasi-experimental study provides two groups of high school students with a design problem in a three hour design experience. One group has…
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Bayesian experimental design for models with intractable likelihoods.
Drovandi, Christopher C; Pettitt, Anthony N
2013-12-01
In this paper we present a methodology for designing experiments for efficiently estimating the parameters of models with computationally intractable likelihoods. The approach combines a commonly used methodology for robust experimental design, based on Markov chain Monte Carlo sampling, with approximate Bayesian computation (ABC) to ensure that no likelihood evaluations are required. The utility function considered for precise parameter estimation is based upon the precision of the ABC posterior distribution, which we form efficiently via the ABC rejection algorithm based on pre-computed model simulations. Our focus is on stochastic models and, in particular, we investigate the methodology for Markov process models of epidemics and macroparasite population evolution. The macroparasite example involves a multivariate process and we assess the loss of information from not observing all variables. © 2013, The International Biometric Society.
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Hanewinkel, Reiner; Isensee, Barbara; Sargent, James D; Morgenstern, Matthis
2010-07-01
To assess the effect of an antismoking advertisement under real-world conditions. Design Quasi-experimental study. Multiplex cinema in Kiel, Germany; 4073 patrons were surveyed after having viewed a movie. Some 4005 patrons were > or = 10 years old (28.7% between 10 and 17 years). A total of 654 subjects (16.3%) were smokers. In the intervention condition (weeks 1 and 3), a 30-second antismoking advertisement-accentuating long-term health consequences of smoking and promoting cessation-was shown prior to all movies; in the control condition (weeks 2 and 4) no such spot was shown. (i) Awareness of smoking in the movie, (ii) approval of smoking in the movie, (iii) attitude towards smoking, (iv) intention to smoke in the future and (v) desire to smoke among smokers. Findings Patrons who were exposed to the antismoking advertisement were more likely to be female, but did not differ with respect to smoking status. After controlling for gender differences, patrons exposed to the antismoking advertisement had (i) higher awareness of smoking in the movies, (ii) lower levels of approval of smoking in the movies, and (iii) a more negative attitude towards smoking in general compared with those not exposed. Among smokers, smoking in the movies increased urge to smoke, but there was no interaction between smoking in the movies and experimental condition. Study results suggest that placing an antismoking advertisement before movies can affect attitudes towards smoking, bolstering evidence in support of such policies.
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Shanks, Ryan A; Robertson, Chuck L; Haygood, Christian S; Herdliksa, Anna M; Herdliska, Heather R; Lloyd, Steven A
2017-01-01
Introductory biology courses provide an important opportunity to prepare students for future courses, yet existing cookbook labs, although important in their own way, fail to provide many of the advantages of semester-long research experiences. Engaging, authentic research experiences aid biology students in meeting many learning goals. Therefore, overlaying a research experience onto the existing lab structure allows faculty to overcome barriers involving curricular change. Here we propose a working model for this overlay design in an introductory biology course and detail a means to conduct this lab with minimal increases in student and faculty workloads. Furthermore, we conducted exploratory factor analysis of the Experimental Design Ability Test (EDAT) and uncovered two latent factors which provide valid means to assess this overlay model's ability to increase advanced experimental design abilities. In a pre-test/post-test design, we demonstrate significant increases in both basic and advanced experimental design abilities in an experimental and comparison group. We measured significantly higher gains in advanced experimental design understanding in students in the experimental group. We believe this overlay model and EDAT factor analysis contribute a novel means to conduct and assess the effectiveness of authentic research experiences in an introductory course without major changes to the course curriculum and with minimal increases in faculty and student workloads.
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Experimental design in chemistry: A tutorial.
Leardi, Riccardo
2009-10-12
In this tutorial the main concepts and applications of experimental design in chemistry will be explained. Unfortunately, nowadays experimental design is not as known and applied as it should be, and many papers can be found in which the "optimization" of a procedure is performed one variable at a time. Goal of this paper is to show the real advantages in terms of reduced experimental effort and of increased quality of information that can be obtained if this approach is followed. To do that, three real examples will be shown. Rather than on the mathematical aspects, this paper will focus on the mental attitude required by experimental design. The readers being interested to deepen their knowledge of the mathematical and algorithmical part can find very good books and tutorials in the references [G.E.P. Box, W.G. Hunter, J.S. Hunter, Statistics for Experimenters: An Introduction to Design, Data Analysis, and Model Building, John Wiley & Sons, New York, 1978; R. Brereton, Chemometrics: Data Analysis for the Laboratory and Chemical Plant, John Wiley & Sons, New York, 1978; R. Carlson, J.E. Carlson, Design and Optimization in Organic Synthesis: Second Revised and Enlarged Edition, in: Data Handling in Science and Technology, vol. 24, Elsevier, Amsterdam, 2005; J.A. Cornell, Experiments with Mixtures: Designs, Models and the Analysis of Mixture Data, in: Series in Probability and Statistics, John Wiley & Sons, New York, 1991; R.E. Bruns, I.S. Scarminio, B. de Barros Neto, Statistical Design-Chemometrics, in: Data Handling in Science and Technology, vol. 25, Elsevier, Amsterdam, 2006; D.C. Montgomery, Design and Analysis of Experiments, 7th edition, John Wiley & Sons, Inc., 2009; T. Lundstedt, E. Seifert, L. Abramo, B. Thelin, A. Nyström, J. Pettersen, R. Bergman, Chemolab 42 (1998) 3; Y. Vander Heyden, LC-GC Europe 19 (9) (2006) 469].
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Plasmons in quasi-two-dimensional metals
NASA Astrophysics Data System (ADS)
da Jornada, Felipe H.; Xian, Lede; Sen, H. Sener; Rubio, Angel; Louie, Steven G.
We employ ab initio density-functional theory (DFT) and GW calculations to understand and predict the plasmon dispersion in quasi-two-dimensional (quasi-2D) metals. We show that, unlike what is found in idealized 2D electron gases, plasmons are virtually dispersionless in real quasi-2D metals for a wide range of excitation wave vectors that are experimentally accessible. We further develop a simpler model that captures this plasmon dispersion in quasi-2D metals and which depends on a single parameter: the characteristic screening length due to interband transitions. Our ab initio calculations further predict that monolayer metallic transition metal dichalcogenides are excellent candidates to explore these dispersionless (flat) plasmons: having large excitation energy that is away from the Landau damping regions makes them ideal systems to support long-lived, spatially-localized 2D plasmons which are highly tunable with substrate. This work is supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division; the National Science Foundation; the European Research Council project (ERC-2015-AdG-694097), and the AFOSR Grant No. FA2386-15-1-0006 AOARD 144088.
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Fakhri, Moloud; Hamzehgardeshi, Zeinab; Hajikhani Golchin, Nayereh Azam; Komili, Abdulhay
2012-03-15
Research in the past decade has revealed average to poor menstrual health among many Iranian girls. The present study investigated the effectiveness of a health promotion project on improving menstrual health in adolescent girls in Iran. A quasi-experimental study was conducted to evaluate the effectiveness of the health intervention program. A total of 698 students (study participants and controls) in several schools in Mazandaran province, Iran were included. The project comprised 10 two-hour educational sessions. Educational topics included the significance of adolescence, physical and emotional changes during adolescence, pubertal and menstruation health and premenstrual syndrome. A self-administered questionnaire measuring demographic characteristics, behaviors during menstruation, menstrual patterns, sources of information about menstruation and personal health data was administered. The questionnaire was administered to all participating students after the experimental group received the training. Among the most significant results was the impact of educational sessions on bathing and genital hygiene. A total of 61.6% in the experimental group compared with 49.3% in the control group engaged in usual bathing during menstruation (p = 0.002). Individual health status was significantly statistically correlated with menstrual health. Attitude towards menstruation was also significantly related to menstrual health. The present study confirms that educational interventions, such as the health promotion project in this study, can be quite effective in promoting menstrual health.
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2012-01-01
Background Research in the past decade has revealed average to poor menstrual health among many Iranian girls. The present study investigated the effectiveness of a health promotion project on improving menstrual health in adolescent girls in Iran. Methods A quasi-experimental study was conducted to evaluate the effectiveness of the health intervention program. A total of 698 students (study participants and controls) in several schools in Mazandaran province, Iran were included. The project comprised 10 two-hour educational sessions. Educational topics included the significance of adolescence, physical and emotional changes during adolescence, pubertal and menstruation health and premenstrual syndrome. A self-administered questionnaire measuring demographic characteristics, behaviors during menstruation, menstrual patterns, sources of information about menstruation and personal health data was administered. The questionnaire was administered to all participating students after the experimental group received the training. Results Among the most significant results was the impact of educational sessions on bathing and genital hygiene. A total of 61.6% in the experimental group compared with 49.3% in the control group engaged in usual bathing during menstruation (p = 0.002). Individual health status was significantly statistically correlated with menstrual health. Attitude towards menstruation was also significantly related to menstrual health. Conclusions The present study confirms that educational interventions, such as the health promotion project in this study, can be quite effective in promoting menstrual health. PMID:22420743
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Smoke-Free School Policy and Exposure to Secondhand Smoke: A Quasi-Experimental Analysis.
Azagba, Sunday; Kennedy, Ryan David; Baskerville, Neill Bruce
2016-02-01
Tobacco control prevention efforts are important to protect people from exposure to dangerous tobacco smoke, support cessation, and reduce tobacco-use initiation. While smoke-free laws have been a widespread tobacco control strategy, little work has been done to examine the impact of smoke-free school policies. The objective of this study is to evaluate the impact of provincial smoke-free school ground policies on youth-reported exposure to secondhand smoke (SHS) on school property. This study used a nationally representative sample of 20 388 youth aged 15-18 from the 2005-2012 Canadian Tobacco Use Monitoring Survey. A quasi-experimental design was used to evaluate the impact of smoke-free school policies on SHS exposure. Approximately over half (52%) of respondents reported SHS exposure on a school property in the past month. Smoke-free school policy had a statistically significant effect on SHS exposure. Specifically, the adoption of smoke-free school reduced the probability of SHS exposure by about 8 percentage points. Respondents who were smokers were more likely to report being exposed to SHS than nonsmokers. Likewise, those living in urban areas had higher probability of being exposed to SHS than those living in rural parts of Canada. Reported exposure to tobacco smoke did decrease after the introduction of smoke-free ground policies; however, almost half of high-school aged youth report exposure in the last month. Across Canada, provincial health authorities as well as school administers may need to assess the implementation of these smoke-free policies and improve enforcement strategies to further reduce exposure to dangerous SHS. © The Author 2015. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco.
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"Teamwork in hospitals": a quasi-experimental study protocol applying a human factors approach.
Ballangrud, Randi; Husebø, Sissel Eikeland; Aase, Karina; Aaberg, Oddveig Reiersdal; Vifladt, Anne; Berg, Geir Vegard; Hall-Lord, Marie Louise
2017-01-01
Effective teamwork and sufficient communication are critical components essential to patient safety in today's specialized and complex healthcare services. Team training is important for an improved efficiency in inter-professional teamwork within hospitals, however the scientific rigor of studies must be strengthen and more research is required to compare studies across samples, settings and countries. The aims of the study are to translate and validate teamwork questionnaires and investigate healthcare personnel's perception of teamwork in hospitals (Part 1). Further to explore the impact of an inter-professional teamwork intervention in a surgical ward on structure, process and outcome (Part 2). To address the aims, a descriptive, and explorative design (Part 1), and a quasi-experimental interventional design will be applied (Part 2). The study will be carried out in five different hospitals (A-E) in three hospital trusts in Norway. Frontline healthcare personnel in Hospitals A and B, from both acute and non-acute departments, will be invited to respond to three Norwegian translated teamwork questionnaires (Part 1). An inter-professional teamwork intervention in line with the TeamSTEPPS recommend Model of Change will be implemented in a surgical ward at Hospital C. All physicians, registered nurses and assistant nurses in the intervention ward and two control wards (Hospitals D and E) will be invited to to survey their perception of teamwork, team decision making, safety culture and attitude towards teamwork before intervention and after six and 12 months. Adult patients admitted to the intervention surgical unit will be invited to survey their perception of quality of care during their hospital stay before intervention and after six and 12 month. Moreover, anonymous patient registry data from local registers and data from patients' medical records will be collected (Part 2). This study will help to understand the impact of an inter-professional teamwork
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Relation between experimental and non-experimental study designs. HB vaccines: a case study.
Jefferson, T; Demicheli, V
1999-01-01
To examine the relation between experimental and non-experimental study design in vaccinology. Assessment of each study design's capability of testing four aspects of vaccine performance, namely immunogenicity (the capacity to stimulate the immune system), duration of immunity conferred, incidence and seriousness of side effects, and number of infections prevented by vaccination. Experimental and non-experimental studies on hepatitis B (HB) vaccines in the Cochrane Vaccines Field Database. Experimental and non-experimental vaccine study designs are frequently complementary but some aspects of vaccine quality can only be assessed by one of the types of study. More work needs to be done on the relation between study quality and its significance in terms of effect size.
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Halek, Margareta; Dichter, Martin Nikolaus; Quasdorf, Tina; Riesner, Christine; Bartholomeyczik, Sabine
2013-06-01
The main objective of care for people with dementia is the maintenance and promotion of quality of life (Qol). Most of the residents in nursing homes have challenging behaviors that strongly affect their Qol. Person-centered care (PCC) is an approach that aims to achieve the best possible Qol and to reduce challenging behaviors. Dementia Care Mapping (DCM) is a method of implementing PCC that has been used in Germany for several years. However, there are no data on the effectiveness of DCM or the challenges of implementation of DCM in German nursing homes. In this quasi-experimental non-randomized cluster-controlled study, the effects of DCM will be compared to 2 comparison groups. 9 nursing homes will take part: 3 will implement DCM, 3 will implement a comparison intervention using an alternative Qol assessment, and 3 have already implemented DCM. The main effect outcomes are Qol, challenging behaviors, staff attitudes toward dementia, job satisfaction and burnout of caregivers. These outcomes will be measured on 3 data points. Different quantitative and qualitative data sources will be collected through the course of the study to investigate the degree of implementation as well as facilitators of and barriers to the implementation process. This study will provide new information about the effectiveness of DCM and the implementation process of DCM in German nursing homes. The study results will provide important information to guide the national discussion about the improvement of dementia-specific Qol, quality of care in nursing homes and allocation of resources. In addition, the study results will provide information for decision-making and implementation of complex psychosocial interventions such as DCM. The findings will also be important for the design of a subsequent randomized controlled trial (e.g. appropriateness of outcomes and measurements, inclusion criteria for participating nursing homes) and the development of a successful implementation strategy
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NASA Astrophysics Data System (ADS)
Chen, M.; Ju, Y. L.
2017-07-01
Periodic and spontaneous on-off oscillation belongs to the onset and damping behaviors of thermoacoustic engines, and investigations on this phenomenon lead to better operation of the thermoacoustic engines with stable performances. In this paper, the quasi- periodic on-off oscillation in a small-scale traveling wave thermoacoustic heat engine with a resonator length of only 1 m was experimentally investigated. The type of working media, mean pressure and the input heating power are the main operating parameters, which significantly affect the formation of the periodic on-off oscillation. The experimental results demonstrated there was a critical charge pressure over which the periodic on-off oscillation could happen. For the small- scale engine with helium gas as the working media, the mean pressure threshold value was about 1.4 MPa and the on-off oscillation occurred with a single frequency. Using nitrogen and argon gas as the working media, the on-off oscillation was not observed. The reason was qualitatively analyzed as well.
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Designing Studies That Would Address the Multilayered Nature of Health Care
Pennell, Michael; Rhoda, Dale; Hade, Erinn M.; Paskett, Electra D.
2010-01-01
We review design and analytic methods available for multilevel interventions in cancer research with particular attention to study design, sample size requirements, and potential to provide statistical evidence for causal inference. The most appropriate methods will depend on the stage of development of the research and whether randomization is possible. Early on, fractional factorial designs may be used to screen intervention components, particularly when randomization of individuals is possible. Quasi-experimental designs, including time-series and multiple baseline designs, can be useful once the intervention is designed because they require few sites and can provide the preliminary evidence to plan efficacy studies. In efficacy and effectiveness studies, group-randomized trials are preferred when randomization is possible and regression discontinuity designs are preferred otherwise if assignment based on a quantitative score is possible. Quasi-experimental designs may be used, especially when combined with recent developments in analytic methods to reduce bias in effect estimates. PMID:20386057
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Dubovi, Ilana; Dagan, Efrat; Sader Mazbar, Ola; Nassar, Laila; Levy, Sharona T
2018-02-01
Pharmacology is a crucial component of medications administration in nursing, yet nursing students generally find it difficult and self-rate their pharmacology skills as low. To evaluate nursing students learning pharmacology with the Pharmacology Inter-Leaved Learning-Cells environment, a novel approach to modeling biochemical interactions using a multiscale, computer-based model with a complexity perspective based on a small set of entities and simple rules. This environment represents molecules, organelles and cells to enhance the understanding of cellular processes, and combines these cells at a higher scale to obtain whole-body interactions. Sophomore nursing students who learned the pharmacology of diabetes mellitus with the Pharmacology Inter-Leaved Learning-Cells environment (experimental group; n=94) or via a lecture-based curriculum (comparison group; n=54). A quasi-experimental pre- and post-test design was conducted. The Pharmacology-Diabetes-Mellitus questionnaire and the course's final exam were used to evaluate students' knowledge of the pharmacology of diabetes mellitus. Conceptual learning was significantly higher for the experimental than for the comparison group for the course final exam scores (unpaired t=-3.8, p<0.001) and for the Pharmacology-Diabetes-Mellitus questionnaire (U=942, p<0.001). The largest effect size for the Pharmacology-Diabetes-Mellitus questionnaire was for the medication action subscale. Analysis of complex-systems component reasoning revealed a significant difference for micro-macro transitions between the levels (F(1, 82)=6.9, p<0.05). Learning with complexity-based computerized models is highly effective and enhances the understanding of moving between micro and macro levels of the biochemical phenomena, this is then related to better understanding of medication actions. Moreover, the Pharmacology Inter-Leaved Learning-Cells approach provides a more general reasoning scheme for biochemical processes, which enhances
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Reducing salt in bread: a quasi-experimental feasibility study in a bakery in Lima, Peru.
Saavedra-Garcia, Lorena; Sosa-Zevallos, Vanessa; Diez-Canseco, Francisco; Miranda, J Jaime; Bernabe-Ortiz, Antonio
2016-04-01
To explore salt content in bread and to evaluate the feasibility of reducing salt contained in 'pan francés' bread. The study had two phases. Phase 1, an exploratory phase, involved the estimation of salt contained in bread as well as a triangle taste test to establish the amount of salt to be reduced in 'pan francés' bread without detection by consumers. In Phase 2, a quasi-experimental, pre-post intervention study assessed the effects of the introduction of low-salt bread on bakery sales. A municipal bakery in Miraflores, Lima, Peru. Sixty-five clients of the bakery in Phase 1 of the study; sales to usual costumers in Phase 2. On average, there was 1·25 g of salt per 100 g of bread. Sixty-five consumers were enrolled in the triangle taste test: fifty-four (83·1 %) females, mean age 58·9 (sd 13·7) years. Based on taste, bread samples prepared with salt reductions of 10 % (P=0·82) and 20 % (P=0·37) were not discernible from regular bread. The introduction of bread with 20 % of salt reduction, which contained 1 g of salt per 100 g of bread, did not change sales of 'pan francés' (P=0·70) or other types of bread (P=0·36). Results were consistent when using different statistical techniques. The introduction of bread with a 20 % reduction in salt is feasible without affecting taste or bakery sales. Results suggest that these interventions are easily implementable, with the potential to contribute to larger sodium reduction strategies impacting the population's cardiovascular health.
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Kang, Kyungja; Yu, Mi
2018-06-01
Student self-debriefing promotes self-confidence, helps to increase clinical performance, and is a more cost-effective method than is traditional instructor-led debriefing in simulation-based learning. This study compared the effectiveness of debriefing-in terms of the problem-solving process, team effectiveness, debriefing assessment, and debriefing satisfaction-between an experimental group who received both student self-debriefing (SSD) and instructor debriefing (ID) and a control group who received only instructor debriefing. This quasi-experimental study used a pretest-posttest non-equivalent control group design. Two universities in South Korea. A convenience sample of 123 senior nursing students. The data were collected between 15 April and 9 June 2016. Differences in the problem-solving process, team effectiveness, debriefing assessment, and debriefing satisfaction between the SSD + ID group and the ID-only group were measured. The SSD + ID group showed significant improvements in the problem-solving process (t = 4.32, p < .001) and debriefing satisfaction (t = 3.19, p = .002), but not in debriefing assessment (t = 1.67, p = .097) or team effectiveness (t = 1.84, p = .069) compared to ID-only group. Specifically, as the number of student sessions increased, we observed significant differences in problem-solving ability (F = 9.44, p < .001), debriefing satisfaction (F = 7.78, p < .001), and the subdomains of debriefing assessment: 'maintains an engaging environment' (F = 3.78, p = .025), 'structures the debriefing in an organized way' (F = 4.27, p = .016), and 'helps trainees achieve or sustain future performance' (F = 3.17, p = .045). Our results can be used to develop guidelines for effective debriefing following simulation in nursing education. Specifically, combining SSD and ID in simulation debriefing and increasing the number of SSD sessions could help improve the problem
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NASA Astrophysics Data System (ADS)
Masuda, Y.; Cook, J.
2012-12-01
This paper analyzes the impact of improved water access on child school attendance using two years of primary panel data from a quasi-experimental study in Oromiya, Ethiopia. A predominant form of child labor in rural poor households in least developed countries is water collection. Girls are often the primary water collectors for households, and because of the time intensive nature of water collection improved water access may allow for time to be reallocated to schooling (Rosen and Vincent 1999; Nankhuni and Findeis 2004). Understanding how improved water access may increase schooling for girls has important development policy implications. Indeed, abundant research on returns to education suggests increased schooling for girls is tied to improved future child and maternal health, economic opportunities, and lower fertility rates (Handa 1996; Schultz 1998; Michaelowa 2000). The literature to date finds that improved water access leads to increased schooling; however, there still exists a clear gap in the literature for understanding this relationship for two reasons. First, only four studies have directly examined the relationship between improved water access and schooling in sub-Saharan Africa, and analyses have been limited due to the use of cross-sectional data and research designs (Nankhuni and Findeis 2004; Koolwal and Van de Walle 2010; Ndiritu and Nyangan 2011; Nauges and Strand 2011). Indeed, only two studies have attempted to control for the endogenous nature of water access. Second, all studies use a binary school enrollment indicator from household surveys, which may suffer from response bias and may be an imperfect measure for actual schooling. Respondents may feel pressured to report that their children are enrolled in school if, like in Ethiopia, there are compulsory education laws. This may result in an overestimation of school enrollment. In addition, most children from rural poor households combine work and school, and a binary indicator does
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ERIC Educational Resources Information Center
Van Gundy, Karen; Morton, Beth A.; Liu, Hope Q.; Kline, Jennifer
2006-01-01
To explore the effects of web-based instruction (WBI) on math anxiety, the sense of mastery, and global self-esteem, we use quasi-experimental data from undergraduate statistics students in classes assigned to three study conditions, each with varied access to, and incentive for, the use of online technologies. Results suggest that when statistics…
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Considering RNAi experimental design in parasitic helminths.
Dalzell, Johnathan J; Warnock, Neil D; McVeigh, Paul; Marks, Nikki J; Mousley, Angela; Atkinson, Louise; Maule, Aaron G
2012-04-01
Almost a decade has passed since the first report of RNA interference (RNAi) in a parasitic helminth. Whilst much progress has been made with RNAi informing gene function studies in disparate nematode and flatworm parasites, substantial and seemingly prohibitive difficulties have been encountered in some species, hindering progress. An appraisal of current practices, trends and ideals of RNAi experimental design in parasitic helminths is both timely and necessary for a number of reasons: firstly, the increasing availability of parasitic helminth genome/transcriptome resources means there is a growing need for gene function tools such as RNAi; secondly, fundamental differences and unique challenges exist for parasite species which do not apply to model organisms; thirdly, the inherent variation in experimental design, and reported difficulties with reproducibility undermine confidence. Ideally, RNAi studies of gene function should adopt standardised experimental design to aid reproducibility, interpretation and comparative analyses. Although the huge variations in parasite biology and experimental endpoints make RNAi experimental design standardization difficult or impractical, we must strive to validate RNAi experimentation in helminth parasites. To aid this process we identify multiple approaches to RNAi experimental validation and highlight those which we deem to be critical for gene function studies in helminth parasites.
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Quasi-periodicity of vector solitons in a graphene mode-locked fiber laser
NASA Astrophysics Data System (ADS)
Song, Yu Feng; Li, Lei; Tang, Ding Yuan; Shen, De Yuan
2013-12-01
We report on the experimental observation of quasi-periodic dynamics of vector solitons in an erbium-doped fiber laser passively mode-locked with atomic layer graphene. Apart from the stable polarization-locked vector soliton emission, it was found that under certain conditions the fiber laser could also emit vector solitons with quasi-periodic pulse energy variation and polarization rotation during the cavity roundtrips. We show that the physical mechanism for the quasi-periodic vector soliton evolution is cavity-induced soliton modulation instability. Quasi-periodic evolution of multiple vector solitons was also observed in the same laser.
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Using experimental design to define boundary manikins.
Bertilsson, Erik; Högberg, Dan; Hanson, Lars
2012-01-01
When evaluating human-machine interaction it is central to consider anthropometric diversity to ensure intended accommodation levels. A well-known method is the use of boundary cases where manikins with extreme but likely measurement combinations are derived by mathematical treatment of anthropometric data. The supposition by that method is that the use of these manikins will facilitate accommodation of the expected part of the total, less extreme, population. In literature sources there are differences in how many and in what way these manikins should be defined. A similar field to the boundary case method is the use of experimental design in where relationships between affecting factors of a process is studied by a systematic approach. This paper examines the possibilities to adopt methodology used in experimental design to define a group of manikins. Different experimental designs were adopted to be used together with a confidence region and its axes. The result from the study shows that it is possible to adapt the methodology of experimental design when creating groups of manikins. The size of these groups of manikins depends heavily on the number of key measurements but also on the type of chosen experimental design.
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Magic Mirror, on the Wall-Which Is the Right Study Design of Them All?-Part I.
Vetter, Thomas R
2017-06-01
The assessment of a new or existing treatment or intervention typically answers 1 of 3 research-related questions: (1) "Can it work?" (efficacy); (2) "Does it work?" (effectiveness); and (3) "Is it worth it?" (efficiency or cost-effectiveness). There are a number of study designs that on a situational basis are appropriate to apply in conducting research. These study designs are classified as experimental, quasi-experimental, or observational, with observational studies being further divided into descriptive and analytic categories. This first of a 2-part statistical tutorial reviews these 3 salient research questions and describes a subset of the most common types of experimental and quasi-experimental study design. Attention is focused on the strengths and weaknesses of each study design to assist in choosing which is appropriate for a given study objective and hypothesis as well as the particular study setting and available resources and data. Specific studies and papers are highlighted as examples of a well-chosen, clearly stated, and properly executed study design type.
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Shanks, Ryan A.; Robertson, Chuck L.; Haygood, Christian S.; Herdliksa, Anna M.; Herdliska, Heather R.; Lloyd, Steven A.
2017-01-01
Introductory biology courses provide an important opportunity to prepare students for future courses, yet existing cookbook labs, although important in their own way, fail to provide many of the advantages of semester-long research experiences. Engaging, authentic research experiences aid biology students in meeting many learning goals. Therefore, overlaying a research experience onto the existing lab structure allows faculty to overcome barriers involving curricular change. Here we propose a working model for this overlay design in an introductory biology course and detail a means to conduct this lab with minimal increases in student and faculty workloads. Furthermore, we conducted exploratory factor analysis of the Experimental Design Ability Test (EDAT) and uncovered two latent factors which provide valid means to assess this overlay model’s ability to increase advanced experimental design abilities. In a pre-test/post-test design, we demonstrate significant increases in both basic and advanced experimental design abilities in an experimental and comparison group. We measured significantly higher gains in advanced experimental design understanding in students in the experimental group. We believe this overlay model and EDAT factor analysis contribute a novel means to conduct and assess the effectiveness of authentic research experiences in an introductory course without major changes to the course curriculum and with minimal increases in faculty and student workloads. PMID:28904647
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Panda, Bhuputra; Pati, Sanghamitra; Nallala, Srinivas; Chauhan, Abhimanyu S; Anasuya, Anita; Som, Meena; Zodpey, Sanjay
2015-01-01
Routine immunization (RI) is a key child survival intervention. Ensuring acceptable standards of RI service delivery is critical for optimal outcomes. Accumulated evidences suggest that 'supportive supervision' improves the quality of health care services in general. During 2009-2010, the Government of Odisha and UNICEF jointly piloted this strategy in four districts to improve RI program outcomes. The present study aims to assess the effect of this strategy on improvement of skills and practices at immunization session sites. A quasi-experimental 'post-test only' study design was adopted to compare the opinion and practices of frontline health workers and their supervisors in four intervention districts (IDs) with two control districts (CDs). Altogether, we interviewed 111 supervisor-supervisee (health worker) pairs using semi-structured interview schedules and case vignettes. We also directly observed health workers' practices during immunization sessions at 111 sites. Data were analyzed with SPSS version 16.0. The mean knowledge score of supervisors in CDs was significantly higher than in intervention groups. Variegated responses were obtained on case vignettes. The control group performed better in solving certain hypothetically asked problems, whereas the intervention group scored better in others. Health workers in IDs gave a lower rating to their respective supervisors' knowledge, skill, and frequency of supervision. Logistics and vaccine availability were better in CDs. Notwithstanding other limitations, supportive supervision may not have independent effects on improving the quality of immunization services. Addressing systemic issues, such as the availability of essential logistics, supply chain management, timely indenting, and financial resources, could complement the supportive supervision strategy in improving immunization service delivery.
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16 CFR 1702.10 - Human experimental data involving the testing of human subjects.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 16 Commercial Practices 2 2011-01-01 2011-01-01 false Human experimental data involving the testing of human subjects. 1702.10 Section 1702.10 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION... PACKAGING ACT REQUIREMENTS; PETITION PROCEDURES AND REQUIREMENTS § 1702.10 Human experimental data involving...
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16 CFR 1702.10 - Human experimental data involving the testing of human subjects.
Code of Federal Regulations, 2012 CFR
2012-01-01
... 16 Commercial Practices 2 2012-01-01 2012-01-01 false Human experimental data involving the testing of human subjects. 1702.10 Section 1702.10 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION... PACKAGING ACT REQUIREMENTS; PETITION PROCEDURES AND REQUIREMENTS § 1702.10 Human experimental data involving...
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16 CFR 1702.10 - Human experimental data involving the testing of human subjects.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 16 Commercial Practices 2 2014-01-01 2014-01-01 false Human experimental data involving the testing of human subjects. 1702.10 Section 1702.10 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION... PACKAGING ACT REQUIREMENTS; PETITION PROCEDURES AND REQUIREMENTS § 1702.10 Human experimental data involving...
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16 CFR 1702.10 - Human experimental data involving the testing of human subjects.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Human experimental data involving the testing of human subjects. 1702.10 Section 1702.10 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION... PACKAGING ACT REQUIREMENTS; PETITION PROCEDURES AND REQUIREMENTS § 1702.10 Human experimental data involving...
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Experimental Design for Hanford Low-Activity Waste Glasses with High Waste Loading
DOE Office of Scientific and Technical Information (OSTI.GOV)
Piepel, Gregory F.; Cooley, Scott K.; Vienna, John D.
This report discusses the development of an experimental design for the initial phase of the Hanford low-activity waste (LAW) enhanced glass study. This report is based on a manuscript written for an applied statistics journal. Appendices A, B, and E include additional information relevant to the LAW enhanced glass experimental design that is not included in the journal manuscript. The glass composition experimental region is defined by single-component constraints (SCCs), linear multiple-component constraints (MCCs), and a nonlinear MCC involving 15 LAW glass components. Traditional methods and software for designing constrained mixture experiments with SCCs and linear MCCs are not directlymore » applicable because of the nonlinear MCC. A modification of existing methodology to account for the nonlinear MCC was developed and is described in this report. One of the glass components, SO 3, has a solubility limit in glass that depends on the composition of the balance of the glass. A goal was to design the experiment so that SO 3 would not exceed its predicted solubility limit for any of the experimental glasses. The SO 3 solubility limit had previously been modeled by a partial quadratic mixture model expressed in the relative proportions of the 14 other components. The partial quadratic mixture model was used to construct a nonlinear MCC in terms of all 15 components. In addition, there were SCCs and linear MCCs. This report describes how a layered design was generated to (i) account for the SCCs, linear MCCs, and nonlinear MCC and (ii) meet the goals of the study. A layered design consists of points on an outer layer, and inner layer, and a center point. There were 18 outer-layer glasses chosen using optimal experimental design software to augment 147 existing glass compositions that were within the LAW glass composition experimental region. Then 13 inner-layer glasses were chosen with the software to augment the existing and outer-layer glasses. The
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Vázquez, María-Luisa; Vargas, Ingrid; Unger, Jean-Pierre; De Paepe, Pierre; Mogollón-Pérez, Amparo Susana; Samico, Isabella; Albuquerque, Paulette; Eguiguren, Pamela; Cisneros, Angelica Ivonne; Rovere, Mario; Bertolotto, Fernando
2015-01-01
Introduction Although fragmentation in the provision of healthcare is considered an important obstacle to effective care, there is scant evidence on best practices in care coordination in Latin America. The aim is to evaluate the effectiveness of a participatory shared care strategy in improving coordination across care levels and related care quality, in health services networks in six different healthcare systems of Latin America. Methods and analysis A controlled before and after quasi-experimental study taking a participatory action research approach. In each country, two comparable healthcare networks were selected—intervention and control. The study contains four phases: (1) A baseline study to establish network performance in care coordination and continuity across care levels, using (A) qualitative methods: semi-structured interviews and focus groups with a criterion sample of health managers, professionals and users; and (B) quantitative methods: two questionnaire surveys with samples of 174 primary and secondary care physicians and 392 users with chronic conditions per network. Sample size was calculated to detect a proportion difference of 15% and 10%, before and after intervention (α=0.05; β=0.2 in a two-sided test); (2) a bottom-up participatory design and implementation of shared care strategies involving micro-level care coordination interventions to improve the adequacy of patient referral and information transfer. Strategies are selected through a participatory process by the local steering committee (local policymakers, health care network professionals, managers, users and researchers), supported by appropriate training; (3) Evaluation of the effectiveness of interventions by measuring changes in levels of care coordination and continuity 18 months after implementation, applying the same design as in the baseline study; (4) Cross-country comparative analysis. Ethics and dissemination This study complies with international and national legal
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NASA Technical Reports Server (NTRS)
Usab, William J., Jr.; Jiang, Yi-Tsann
1991-01-01
The objective of the present research is to develop a general solution adaptive scheme for the accurate prediction of inviscid quasi-three-dimensional flow in advanced compressor and turbine designs. The adaptive solution scheme combines an explicit finite-volume time-marching scheme for unstructured triangular meshes and an advancing front triangular mesh scheme with a remeshing procedure for adapting the mesh as the solution evolves. The unstructured flow solver has been tested on a series of two-dimensional airfoil configurations including a three-element analytic test case presented here. Mesh adapted quasi-three-dimensional Euler solutions are presented for three spanwise stations of the NASA rotor 67 transonic fan. Computed solutions are compared with available experimental data.
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Chang, Hsiao-Yun Annie; Chan, Luke; Siren, Betty
2013-06-01
This is a report of a study which evaluated simulation-based learning as a teaching strategy for improving participants' ENP reading proficiency in the senior college program of students whose first language is Chinese, not English. Simulation-based learning is known to be one of most effective teaching strategies in the healthcare professional curricula, which brings a clinical setting into the classroom. However, developing English reading skills for English written nursing journals through simulation-based learning in the nursing curricula, is largely unknown. We used a quasi-experimental approach with nonequivalent control group design to collect the causal connections between intervention and outcomes. 101 students were enrolled in this study (response rate 92.6%) of these 48 students volunteered for the intervention group, and 53 students for the control group. The findings indicated that the intervention group had significantly higher mean scores in ENP reading proficiency with unknown words in the article (p=.004), vocabulary (p<.001), and comprehension (p<.001) compared to the control group. Also, the intervention students showed more improvement in their English reading, both from quantitative and qualitative findings. Simulation-based learning may have some advantages in improving the English reading ability on English written nursing journals among nursing students. However, the benefits to the students of this study is still to be determined, and further exploration is needed with well designed research and a universal method of outcome measurement. Copyright © 2012 Elsevier Ltd. All rights reserved.
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Photonic quasi-crystal terahertz lasers
Vitiello, Miriam Serena; Nobile, Michele; Ronzani, Alberto; Tredicucci, Alessandro; Castellano, Fabrizio; Talora, Valerio; Li, Lianhe; Linfield, Edmund H.; Davies, A. Giles
2014-01-01
Quasi-crystal structures do not present a full spatial periodicity but are nevertheless constructed starting from deterministic generation rules. When made of different dielectric materials, they often possess fascinating optical properties, which lie between those of periodic photonic crystals and those of a random arrangement of scatterers. Indeed, they can support extended band-like states with pseudogaps in the energy spectrum, but lacking translational invariance, they also intrinsically feature a pattern of ‘defects’, which can give rise to critically localized modes confined in space, similar to Anderson modes in random structures. If used as laser resonators, photonic quasi-crystals open up design possibilities that are simply not possible in a conventional periodic photonic crystal. In this letter, we exploit the concept of a 2D photonic quasi crystal in an electrically injected laser; specifically, we pattern the top surface of a terahertz quantum-cascade laser with a Penrose tiling of pentagonal rotational symmetry, reaching 0.1–0.2% wall-plug efficiencies and 65 mW peak output powers with characteristic surface-emitting conical beam profiles, result of the rich quasi-crystal Fourier spectrum. PMID:25523102
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Photonic quasi-crystal terahertz lasers
NASA Astrophysics Data System (ADS)
Vitiello, Miriam Serena; Nobile, Michele; Ronzani, Alberto; Tredicucci, Alessandro; Castellano, Fabrizio; Talora, Valerio; Li, Lianhe; Linfield, Edmund H.; Davies, A. Giles
2014-12-01
Quasi-crystal structures do not present a full spatial periodicity but are nevertheless constructed starting from deterministic generation rules. When made of different dielectric materials, they often possess fascinating optical properties, which lie between those of periodic photonic crystals and those of a random arrangement of scatterers. Indeed, they can support extended band-like states with pseudogaps in the energy spectrum, but lacking translational invariance, they also intrinsically feature a pattern of ‘defects’, which can give rise to critically localized modes confined in space, similar to Anderson modes in random structures. If used as laser resonators, photonic quasi-crystals open up design possibilities that are simply not possible in a conventional periodic photonic crystal. In this letter, we exploit the concept of a 2D photonic quasi crystal in an electrically injected laser; specifically, we pattern the top surface of a terahertz quantum-cascade laser with a Penrose tiling of pentagonal rotational symmetry, reaching 0.1-0.2% wall-plug efficiencies and 65 mW peak output powers with characteristic surface-emitting conical beam profiles, result of the rich quasi-crystal Fourier spectrum.
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Photonic quasi-crystal terahertz lasers.
Vitiello, Miriam Serena; Nobile, Michele; Ronzani, Alberto; Tredicucci, Alessandro; Castellano, Fabrizio; Talora, Valerio; Li, Lianhe; Linfield, Edmund H; Davies, A Giles
2014-12-19
Quasi-crystal structures do not present a full spatial periodicity but are nevertheless constructed starting from deterministic generation rules. When made of different dielectric materials, they often possess fascinating optical properties, which lie between those of periodic photonic crystals and those of a random arrangement of scatterers. Indeed, they can support extended band-like states with pseudogaps in the energy spectrum, but lacking translational invariance, they also intrinsically feature a pattern of 'defects', which can give rise to critically localized modes confined in space, similar to Anderson modes in random structures. If used as laser resonators, photonic quasi-crystals open up design possibilities that are simply not possible in a conventional periodic photonic crystal. In this letter, we exploit the concept of a 2D photonic quasi crystal in an electrically injected laser; specifically, we pattern the top surface of a terahertz quantum-cascade laser with a Penrose tiling of pentagonal rotational symmetry, reaching 0.1-0.2% wall-plug efficiencies and 65 mW peak output powers with characteristic surface-emitting conical beam profiles, result of the rich quasi-crystal Fourier spectrum.
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Tobacco control policies and perinatal health: a national quasi-experimental study.
Peelen, Myrthe J; Sheikh, Aziz; Kok, Marjolein; Hajenius, Petra; Zimmermann, Luc J; Kramer, Boris W; Hukkelhoven, Chantal W; Reiss, Irwin K; Mol, Ben W; Been, Jasper V
2016-04-22
We investigated whether changes in perinatal outcomes occurred following introduction of key tobacco control policies in the Netherlands: smoke-free legislation in workplaces plus a tobacco tax increase and mass media campaign (January-February 2004); and extension of the smoke-free law to the hospitality industry, accompanied by another tax increase and mass media campaign (July 2008). This was a national quasi-experimental study using Netherlands Perinatal Registry data (2000-2011; registration: ClinicalTrials.gov NCT02189265). Primary outcome measures were: perinatal mortality, preterm birth, and being small-for-gestational age (SGA). The association with timing of the tobacco control policies was investigated using interrupted time series logistic regression analyses with adjustment for confounders. Among 2,069,695 singleton births, there were 13,027 (0.6%) perinatal deaths, 116,043 (5.6%) preterm live-births and 187,966 (9.1%) SGA live-births. The 2004 policies were not associated with significant changes in the odds of developing any of the primary outcomes. After the 2008 policy change, a -4.4% (95% CI -2.4; -6.4, p < 0.001) decrease in odds of being SGA was observed. A reduction in SGA births, but not preterm birth or perinatal mortality, was observed in the Netherlands after extension of the smoke-free workplace law to bars and restaurants in conjunction with a tax increase and mass media campaign.
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Tobacco control policies and perinatal health: a national quasi-experimental study
Peelen, Myrthe J.; Sheikh, Aziz; Kok, Marjolein; Hajenius, Petra; Zimmermann, Luc J.; Kramer, Boris W.; Hukkelhoven, Chantal W.; Reiss, Irwin K.; Mol, Ben W.; Been, Jasper V.
2016-01-01
We investigated whether changes in perinatal outcomes occurred following introduction of key tobacco control policies in the Netherlands: smoke-free legislation in workplaces plus a tobacco tax increase and mass media campaign (January-February 2004); and extension of the smoke-free law to the hospitality industry, accompanied by another tax increase and mass media campaign (July 2008). This was a national quasi-experimental study using Netherlands Perinatal Registry data (2000–2011; registration: ClinicalTrials.gov NCT02189265). Primary outcome measures were: perinatal mortality, preterm birth, and being small-for-gestational age (SGA). The association with timing of the tobacco control policies was investigated using interrupted time series logistic regression analyses with adjustment for confounders. Among 2,069,695 singleton births, there were 13,027 (0.6%) perinatal deaths, 116,043 (5.6%) preterm live-births and 187,966 (9.1%) SGA live-births. The 2004 policies were not associated with significant changes in the odds of developing any of the primary outcomes. After the 2008 policy change, a -4.4% (95% CI -2.4; -6.4, p < 0.001) decrease in odds of being SGA was observed. A reduction in SGA births, but not preterm birth or perinatal mortality, was observed in the Netherlands after extension of the smoke-free workplace law to bars and restaurants in conjunction with a tax increase and mass media campaign. PMID:27103591
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Kimani-Murage, E W; Norris, S A; Mutua, M K; Wekesah, F; Wanjohi, M; Muhia, N; Muriuki, P; Egondi, T; Kyobutungi, C; Ezeh, A C; Musoke, R N; McGarvey, S T; Madise, N J; Griffiths, P L
2016-04-01
Early nutrition is critical for later health and sustainable development. We determined potential effectiveness of the Kenyan Community Health Strategy in promoting exclusive breastfeeding (EBF) in urban poor settings in Nairobi, Kenya. We used a quasi-experimental study design, based on three studies [Pre-intervention (2007-2011; n=5824), Intervention (2012-2015; n=1110) and Comparison (2012-2014; n=487)], which followed mother-child pairs longitudinally to establish EBF rates from 0 to 6 months. The Maternal, Infant and Young Child Nutrition (MIYCN) study was a cluster randomized trial; the control arm (MIYCN-Control) received standard care involving community health workers (CHWs) visits for counselling on antenatal and postnatal care. The intervention arm (MIYCN-Intervention) received standard care and regular MIYCN counselling by trained CHWs. Both groups received MIYCN information materials. We tested differences in EBF rates from 0 to 6 months among four study groups (Pre-intervention, MIYCN-Intervention, MIYCN-Control and Comparison) using a χ(2) test and logistic regression. At 6 months, the prevalence of EBF was 2% in the Pre-intervention group compared with 55% in the MIYCN-Intervention group, 55% in the MIYCN-Control group and 3% in the Comparison group (P<0.05). After adjusting for baseline characteristics, the odds ratio for EBF from birth to 6 months was 66.9 (95% CI 45.4-96.4), 84.3 (95% CI 40.7-174.6) and 3.9 (95% CI 1.8-8.4) for the MIYCN-Intervention, MIYCN-Control and Comparison group, respectively, compared with the Pre-intervention group. There is potential effectiveness of the Kenya national Community Health Strategy in promoting EBF in urban poor settings where health care access is limited.
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Cummins, Steven; Petticrew, Mark; Higgins, Cassie; Findlay, Anne; Sparks, Leigh
2005-12-01
To assess the effect on fruit and vegetable consumption, self reported, and psychological health of a "natural experiment"-the introduction of large scale food retailing in a deprived Scottish community. Prospective quasi-experimental design comparing baseline and follow up data in an "intervention" community with a matched "comparison" community in Glasgow, UK. 412 men and women aged 16 or over for whom follow up data on fruit and vegetable consumption and GHQ-12 were available. Fruit and vegetable consumption in portions per day, poor self reported health, and poor psychological health (GHQ-12). Adjusting for age, sex, educational attainment, and employment status there was no population impact on daily fruit and vegetable consumption, self reported, and psychological health. There was some evidence for a net reduction in the prevalence of poor psychological health for residents who directly engaged with the intervention. Government policy has advocated using large scale food retailing as a social intervention to improve diet and health in poor communities. In contrast with a previous uncontrolled study this study did not find evidence for a net intervention effect on fruit and vegetable consumption, although there was evidence for an improvement in psychological health for those who directly engaged with the intervention. Although definitive conclusions about the effect of large scale retailing on diet and health in deprived communities cannot be drawn from non-randomised controlled study designs, evaluations of the impacts of natural experiments may offer the best opportunity to generate evidence about the health impacts of retail interventions in poor communities.
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Lee, Danbi; Fischer, Heidi; Zera, Sarah; Robertson, Rosetta; Hammel, Joy
2017-12-01
Background People with stroke often find discharge from rehabilitation distressing because they do not feel prepared to participate in life roles as they want. A self-management approach can facilitate improvement in confidence and ability to manage post-stroke community living and participation after transitioning into the community. Objective To evaluate the feasibility and effectiveness of the Improving Participation After Stroke Self-management program - Rehab version (IPASS-R) in a day rehabilitation setting. Methods We used a mixed-method non-randomized quasi-experimental design. The IPASS-R program is a six-session group-based intervention led by a trained occupational therapist and lay person with stroke. The program uses an efficacy building approach to support aging adults to maintain active participation in home and community activities post-stroke. Primary outcome measures were the Reintegration to Normal Living Index (RNLI), Stroke Impact Scale (SIS), and Participation Strategies Self-Efficacy Scale. Qualitative feedback was collected post-treatment. Results Seventeen participants with stroke (intervention n = 9; control n = 8) were enrolled across two sites. Non-parametric effect sizes calculated using the Wilcoxon Signed-Rank test revealed larger effects on RNLI and SIS outcomes in the intervention group. The Mann-Whitney U test showed significant differences between the two groups' changes in scores on perceived recovery and strength. Conclusions The result shows that IPASS-R has the potential to be integrated into a day rehabilitation setting with a positive impact on community integration and perceived recovery outcomes. Future study is needed to investigate the IPASS-R with a larger sample size and more rigorous study design.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Chen, Dong; Zhou, Jun, E-mail: zhoujun@nbu.edu.cn; Rippa, Massimo
A set of periodic and quasi-periodic Au nanoarrays with different morphologies have been fabricated by using electron beam lithography technique, and their optical properties have been examined experimentally and analyzed theoretically by scanning near-field optical microscope and finite element method, respectively. Results present that the localized surface plasmon resonance of the as-prepared Au nanoarrays exhibit the structure-depended characteristics. Comparing with the periodic nanoarrays, the quasi-periodic ones demonstrate stronger electric field enhancement, especially for Thue-Morse nanoarray. Meanwhile, the surface enhanced Raman scattering (SERS) spectra of 4-mercaptobenzoic acid molecular labeled nanoarrays show that the quasi-periodic nanoarrays exhibit distinct SERS enhancement, for example,more » a higher enhancement factor of ∼10{sup 7} is obtained for the Thue-Morse nanoarray consisted of square pillars of 100 nm size. Therefore, it is significant to optimally design and fabricate the chip-scale quasi-periodic nanoarrays with high localized electric field enhancement for SERS applications in biosensing field.« less
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ERIC Educational Resources Information Center
Wheeler, Kimberly W.
2014-01-01
This quasi-experimental pretest, posttest nonequivalent control group study investigated the comprehension scores and motivation levels of post-secondary remedial reading students in a two-year technical college in Northwest Georgia using an eBook, an eBook with audio, and a print book. After reading a module on Purpose and Tone in the three book…
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Ashton, Carol M; Khan, Myrna M; Johnson, Michael L; Walder, Annette; Stanberry, Elizabeth; Beyth, Rebecca J; Collins, Tracie C; Gordon, Howard S; Haidet, Paul; Kimmel, Barbara; Kolpakchi, Anna; Lu, Lee B; Naik, Aanand D; Petersen, Laura A; Singh, Hardeep; Wray, Nelda P
2007-02-13
Despite recent high-quality evidence for their cost-effectiveness, thiazides are underused for controlling hypertension. The goal of this study was to design and test a practice-based intervention aimed at increasing the use of thiazide-based antihypertensive regimens. This quasi-experimental study was carried out in general medicine ambulatory practices of a large, academically-affiliated Veterans Affairs hospital. The intervention group consisted of the practitioners (13 staff and 215 trainees), nurses, and patients (3,502) of the teaching practice; non-randomized concurrent controls were the practitioners (31 providers) and patients (18,292) of the non-teaching practices. Design of the implementation intervention was based on Rogers' Diffusion of Innovations model. Over 10.5 months, intervention teams met weekly or biweekly and developed and disseminated informational materials among themselves and to trainees, patients, and administrators. These teams also reviewed summary electronic-medical-record data on thiazide use and blood pressure (BP) goal attainment. Outcome measures were the proportion of hypertensive patients prescribed a thiazide-based regimen, and the proportion of hypertensive patients attaining BP goals regardless of regimen. Thirty-three months of time-series data were available; statistical process control charts, change point analyses, and before-after analyses were used to estimate the intervention's effects. Baseline use of thiazides and rates of BP control were higher in the intervention group than controls. During the intervention, thiazide use and BP control increased in both groups, but changes occurred earlier in the intervention group, and primary change points were observed only in the intervention group. Overall, the pre-post intervention difference in proportion of patients prescribed thiazides was greater in intervention patients (0.091 vs. 0.058; p = 0.0092), as was the proportion achieving BP goals (0.092 vs. 0.044; p = 0
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van de Geer, Joep; Veeger, Nic; Groot, Marieke; Zock, Hetty; Leget, Carlo; Prins, Jelle; Vissers, Kris
2018-02-01
Patients value health-care professionals' attention to their spiritual needs. However, this is undervalued in health-care professionals' education. Additional training is essential for implementation of a national multidisciplinary guideline on spiritual care (SC) in palliative care (PC). Aim of this study is to measure effects of a training program on SC in PC based on the guideline. A pragmatic multicenter trial using a quasi-experimental pretest-posttest design as part of an action research study. Eight multidisciplinary teams in regular wards and 1 team of PC consultants, in 8 Dutch teaching hospitals, received questionnaires before training about perceived barriers for SC, spiritual attitudes and involvement, and SC competencies. The effect on the barriers on SC and SC competencies were measured both 1 and 6 months after the training. For nurses (n = 214), 7 of 8 barriers to SC were decreased after 1 month, but only 2 were still after 6 months. For physicians (n = 41), the training had no effect on the barriers to SC. Nurses improved in 4 of 6 competencies after both 1 and 6 months. Physicians improved in 3 of 6 competencies after 1 month but in only 1 competency after 6 months. Concise SC training programs for clinical teams can effect quality of care, by improving hospital staff competencies and decreasing the barriers they perceive. Differences in the effects of the SC training on nurses and physicians show the need for further research on physicians' educational needs on SC.
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Compression dynamics of quasi-spherical wire arrays with different linear mass profiles
DOE Office of Scientific and Technical Information (OSTI.GOV)
Mitrofanov, K. N., E-mail: mitrofan@triniti.ru; Aleksandrov, V. V.; Gritsuk, A. N.
Results of experimental studies of the implosion of quasi-spherical wire (or metalized fiber) arrays are presented. The goal of the experiments was to achieve synchronous three-dimensional compression of the plasma produced in different regions of a quasi-spherical array into its geometrical center. To search for optimal synchronization conditions, quasi-spherical arrays with different initial profiles of the linear mass were used. The following dependences of the linear mass on the poloidal angle were used: m{sub l}(θ) ∝ sin{sup –1}θ and m{sub l}(θ) ∝ sin{sup –2}θ. The compression dynamics of such arrays was compared with that of quasi-spherical arrays without linear massmore » profiling, m{sub l}(θ) = const. To verify the experimental data, the spatiotemporal dynamics of plasma compression in quasi-spherical arrays was studied using various diagnostics. The experiments on three-dimensional implosion of quasi-spherical arrays made it possible to study how the frozen-in magnetic field of the discharge current penetrates into the array. By measuring the magnetic field in the plasma of a quasi-spherical array, information is obtained on the processes of plasma production and formation of plasma flows from the wire/fiber regions with and without an additionally deposited mass. It is found that penetration of the magnetic flux depends on the initial linear mass profile m{sub l}(θ) of the quasi-spherical array. From space-resolved spectral measurements and frame imaging of plasma X-ray emission, information is obtained on the dimensions and shape of the X-ray source formed during the implosion of a quasi-spherical array. The intensity of this source is estimated and compared with that of the Z-pinch formed during the implosion of a cylindrical array.« less
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Modeling Gene-Environment Interactions With Quasi-Natural Experiments.
Schmitz, Lauren; Conley, Dalton
2017-02-01
This overview develops new empirical models that can effectively document Gene × Environment (G×E) interactions in observational data. Current G×E studies are often unable to support causal inference because they use endogenous measures of the environment or fail to adequately address the nonrandom distribution of genes across environments, confounding estimates. Comprehensive measures of genetic variation are incorporated into quasi-natural experimental designs to exploit exogenous environmental shocks or isolate variation in environmental exposure to avoid potential confounders. In addition, we offer insights from population genetics that improve upon extant approaches to address problems from population stratification. Together, these tools offer a powerful way forward for G×E research on the origin and development of social inequality across the life course. © 2015 Wiley Periodicals, Inc.
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ERIC Educational Resources Information Center
d'Ham, Cedric; de Vries, Erica; Girault, Isabelle; Marzin, Patricia
2004-01-01
This paper deals with the design process of a remote laboratory for labwork in chemistry. In particular, it focuses on the mutual dependency of theoretical conjectures about learning in the experimental sciences and technological opportunities in creating learning environments. The design process involves a detailed analysis of the expert task and…
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Experimental Study of Grit Particle Enhancement in Non-Shock Ignition
NASA Astrophysics Data System (ADS)
Browning, Richard V.; Peterson, Paul D.; Roemer, Edward L.; Oldenborg, Michael R.; Thompson, Darla G.; Deluca, Racci
2006-07-01
The drop weight impact test is the most commonly used configuration for evaluating sensitivity of explosives to non-shock ignition. Although developed 60 years ago and widely used both as a material compression test and as a test bed for understanding the ignition process itself, little is known about the flow mechanisms or involvement of grit particles as sensitizing agents. In this paper, we present the results of a series of experiments designed to study the flow mechanisms and events leading up to ignition. The experimental configuration used involves two pellet sizes, 3 and 5 mm in diameter, tested with three conditions: (1) smooth steel anvils, (2) standard flint sandpaper, and (3) shed grit particles loaded between the steel anvils and the pellet faces. Diagnostics include optical micrographs, and scanning electron micrographs. Un-reacted samples show a variety of morphologies, including what appear to be quenched reaction sites, even at very low drop heights. Quasi-static crushing experiments were also done to quantify load-time histories.
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Behavior of tunnel form buildings under quasi-static cyclic lateral loading
Yuksel, S.B.; Kalkan, E.
2007-01-01
In this paper, experimental investigations on the inelastic seismic behavior of tunnel form buildings (i.e., box-type or panel systems) are presented. Two four-story scaled building specimens were tested under quasi-static cyclic lateral loading in longitudinal and transverse directions. The experimental results and supplemental finite element simulations collectively indicate that lightly reinforced structural walls of tunnel form buildings may exhibit brittle flexural failure under seismic action. The global tension/compression couple triggers this failure mechanism by creating pure axial tension in outermost shear-walls. This type of failure takes place due to rupturing of longitudinal reinforcement without crushing of concrete, therefore is of particular interest in emphasizing the mode of failure that is not routinely considered during seismic design of shear-wall dominant structural systems.
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NASA Astrophysics Data System (ADS)
Wang, Ying-Mei; Wang, Wen-Xiu; Chen, He-Sheng; Zhang, Kai; Jiang, Yu-Mei; Wang, Xu-Ming; He, Da-Ren
2002-03-01
A system concatenated by two area-preserving maps may be addressed as "quasi- dissipative," since such a system can display dissipative behaviors^1. This is due to noninvertibility induced by discontinuity in the system function. In such a system, the image set of the discontinuous border forms a chaotic quasi-attractor. At a critical control parameter value the quasi-attractor suddenly vanishes. The chaotic iterations escape, via a leaking hole, to an emergent period-8 elliptic island. The hole is the intersection of the chaotic quasi-attractor and the period-8 island. The chaotic quasi-attractor thus changes to chaotic quasi-transients. The scaling behavior that drives the quasi-crisis has been investigated numerically. It reads:
∝ (p-p_c)^-ν , where is defined as the averaged length of quasi-transients. The scaling exponent ν=1.66 ± 0.04. The critical parameter value equals p_c=-1.0069799. ^1 J. Wang et al., Phys.Rev.E, 64(2001)026202. -
Parental involvement laws and fertility behavior.
Levine, Phillip B
2003-09-01
This paper considers the impact of the introduction of laws requiring parental involvement in a minor's decision to abort a pregnancy. State-level data over the 1985-1996 period are used to examine abortion, birth, and pregnancy outcomes, while microdata from the 1988 and 1995 National Surveys of Family Growth (NSFG) are utilized to examine sexual activity and contraception. Quasi-experimental methods are employed that examine whether minors' fertility outcomes were affected in those locations that introduced these laws following their introduction and occurred for minors but not other women. I find that parental involvement laws resulted in fewer abortions for minors resulting from fewer pregnancies; there is no statistically significant impact on births. The reduction in pregnancy seems to be attributable to increased use of contraception rather than a reduction in sexual activity.
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Automotive HMI design and participatory user involvement: review and perspectives.
François, Mathilde; Osiurak, François; Fort, Alexandra; Crave, Philippe; Navarro, Jordan
2017-04-01
Automotive human-machine interface (HMI) design is facing new challenges due to the technological advances of the last decades. The design process has to be adapted in order to address human factors and road safety challenges. It is now widely accepted that user involvement in the HMI design process is valuable. However, the current form of user involvement in industry remains at the stages of concept assessment and usability tests. Moreover, the literature in other fields (e.g. information systems) promotes a broader user involvement with participatory design (i.e. the user is fully involved in the development process). This article reviews the established benefits of participatory design and reveals perspectives for automotive HMI quality improvement in a cognitive ergonomic framework. Practitioner Summary: Automotive HMI quality determines, in part, drivers' ability to perform primary driving tasks while using in-vehicle devices. User involvement in the design process is a key point to contribute to HMI quality. This article reports the potential benefits of a broad involvement from drivers to meet automotive HMI design challenges.
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Educational intervention for collecting sputum for tuberculosis: a quasi-experimental study.
Sicsú, Amélia Nunes; Salem, Julia Ignez; Fujimoto, Luciana Botinelly Mendonça; Gonzales, Roxana Isabel Cardozo; Cardoso, Maria do Socorro de Lucena; Palha, Pedro Fredemir
2016-06-07
to evaluate the quality of the sputum sample before and after the Nursing guidance to patients. this is a quasi-experimental research design, single group type, before and after, non-randomized study. The study enrolled patients with suspected pulmonary tuberculosis, respiratory symptomatic patients for over three weeks, aged over 18 years, of both genders and without tuberculosis history in the last two years. The educational intervention consisted of individualized guidance on the collection of sputum sample, which was based on the guidelines of the Ministry of Health of Brazil and on the explanatory folder delivery. in this study participated 138 patients with suspected pulmonary tuberculosis. The results showed significant increase of the samples with purulent particles, volume greater than 5 mL and increased rate of patients diagnosed with tuberculosis, after the educational intervention. it was shown that after the educational intervention, it was observed sputum samples with better quality, with satisfactory aspect and volume for the effectiveness of the bacilloscopic examination. avaliar a qualidade da amostra de escarro antes e após as orientações de Enfermagem ao paciente. estudo com delineamento de pesquisa quase experimental, do tipo grupo único, antes e depois, não randomizado. Participaram do estudo pacientes com suspeita de tuberculose pulmonar, sintomáticos respiratórios por mais de três semanas, maiores de 18 anos, de ambos os sexos e sem antecedente de tuberculose nos últimos dois anos. A intervenção educativa consistiu em orientações individualizadas sobre a coleta da amostra de escarro, fundamentadas nas diretrizes do Ministério da Saúde do Brasil e na entrega de folder explicativo. participaram 138 pacientes com suspeita de tuberculose pulmonar. Os resultados evidenciaram importante acréscimo das amostras com partículas purulentas, volume maior que 5mL e aumento na taxa de pacientes diagnosticados com tuberculose, após a
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Quasi-modal vibration control by means of active control bearings
NASA Technical Reports Server (NTRS)
Nonami, K.; Fleming, D. P.
1986-01-01
This paper investigates a design method of an active control bearing system with only velocity feedback. The study provides a new quasi-modal control method for a control system design of an active control bearing system in which feedback coefficients are determined on the basis of a modal analysis. Although the number of sensors and actuators is small, this quasi-modal control method produces a control effect close to an ideal modal control.
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Retrieving quasi-phase-matching structure with discrete layer-peeling method.
Zhang, Q W; Zeng, X L; Wang, M; Wang, T Y; Chen, X F
2012-07-02
An approach to reconstruct a quasi-phase-matching grating by using a discrete layer-peeling algorithm is presented. Experimentally measured output spectra of Šolc-type filters, based on uniform and chirped QPM structures, are used in the discrete layer-peeling algorithm. The reconstructed QPM structures are in agreement with the exact structures used in the experiment and the method is verified to be accurate and efficient in quality inspection on quasi-phase-matching grating.
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The Propagation of Errors in Experimental Data Analysis: A Comparison of Pre-and Post-Test Designs
ERIC Educational Resources Information Center
Gorard, Stephen
2013-01-01
Experimental designs involving the randomization of cases to treatment and control groups are powerful and under-used in many areas of social science and social policy. This paper reminds readers of the pre-and post-test, and the post-test only, designs, before explaining briefly how measurement errors propagate according to error theory. The…
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Alam, Nazmul; Alam, Anadil; Fournier, Pierre
2015-01-01
This study used a quasi-experimental pre-post design to test whether short training can improve medicine sellers' (MSs) practices and skills for prevention and control of sexually transmitted infections (STIs) in Bangladesh. The training included lectures, printed materials, and identification of referral sites. Difference-in-differences estimation was used to determine the effects of intervention on key primary and secondary outcomes. Advice given by the MSs in intervention group for partner treatment and condoms use increased significantly by 11% and 9%, respectively, after adjusting for baseline differences in education, religion, age, duration of training, and study site. Referral of clients to qualified service providers increased by 5% in the intervention group compared to the comparison group, but this change was not found to be statistically significant. Significantly higher proportion of MSs in the intervention group recognized the recommended medications as per the national syndromic management guidelines in Bangladesh for treatment of urethral discharge and genital ulcer symptoms. Short training intervention was found to be effective in improving MSs' practice of promoting condom use and partner treatment to the clients. We anticipate the need for broad based training programs of MSs to improve their skills for the prevention and control of STI/HIV in Bangladesh.
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Pahnke, Johan; Lundgren, Tobias; Hursti, Timo; Hirvikoski, Tatja
2014-11-01
Autism spectrum disorder is characterized by social impairments and behavioural inflexibility. In this pilot study, the feasibility and outcomes of a 6-week acceptance and commitment therapy-based skills training group were evaluated in a special school setting using a quasi-experimental design (acceptance and commitment therapy/school classes as usual). A total of 28 high-functioning students with autism spectrum disorder (aged 13-21 years) were assessed using self- and teacher-ratings at pre- and post-assessment and 2-month follow-up. All participants completed the skills training, and treatment satisfaction was high. Levels of stress, hyperactivity and emotional distress were reduced in the treatment group. The acceptance and commitment therapy group also reported increased prosocial behaviour. These changes were stable or further improved at the 2-month follow-up. Larger studies are needed to further evaluate the benefits of acceptance and commitment therapy for autism spectrum disorder. © The Author(s) 2013.
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NASA Astrophysics Data System (ADS)
Azhari, Budi; Prawinnetou, Wassy; Hutama, Dewangga Adhyaksa
2017-03-01
Indonesia has several potential ocean energies to utilize. One of them is tidal wave energy, which the potential is about 49 GW. To convert the tidal wave energy to electricity, linear permanent magnet generator (LPMG) is considered as the best appliance. In this paper, a pico-scale tidal wave power converter was designed using quasi-flat LPMG. The generator was meant to be applied in southern coast of Yogyakarta, Indonesia and was expected to generate 1 kW output. First, a quasi-flat LPMG was designed based on the expected output power and the wave characteristic at the placement site. The design was then simulated using finite element software of FEMM. Finally, the output values were calculated and the output characteristics were analyzed. The results showed that the designed power plant was able to produce output power of 725.78 Wp for each phase, with electrical efficiency of 64.5%. The output characteristics of the LPMG: output power would increase as the average wave height or wave period increases. Besides, the efficiency would increase if the external load resistance increases. Meanwhile the output power of the generator would be maximum at load resistance equals 11 Ω.
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Choe, Kwisoon; Park, Sunghee; Yoo, So Yeon
2014-05-01
In order to help nurses advocate for the patient's human rights and ensure respect for life in clinical situations, it is of utmost importance to improve nursing students' capacity to make ethical decisions. This study compares the effects of two constructivist teaching strategies (action learning and cross-examination debate) on nursing students' recognition of bioethical issues, experience of bioethical issues, and attainment of ethical competence. This study used a quasi-experimental (two-group pretest-posttest) design. A nursing college in South Korea. A total of 93 Korean nursing students participated in the study (46 in the action learning group and 47 in the cross-examination debate group). Participants took a bioethics class employing one or the other of the strategies mentioned, 2h a week for 15 weeks. All participants responded twice to a set of questionnaires, at the beginning of the first session and at the end of the last session. After their bioethics education, the students' recognition of bioethical issues improved for both classes; however, the knowledge of students who had participated in action learning improved more than that of the students in the debate-based class. Students in both groups reported more experience of bioethics and exposure to better-quality instruction in bioethics after their classes than previously. Students in both groups also reported improved ethical competency after this education. Positive effects of action learning and cross-examination debate implemented as teaching strategies on nursing students' understanding of bioethical issues and their ethical competency were identified; these findings will be important in the essential task of teaching bioethics to nursing students in order to foster more ethical decision-making and other ethical behavior. © 2013.
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Deater-Deckard, Kirby
2016-05-01
Most of the individual difference variance in the population is found within families, yet studying the processes causing this variation is difficult due to confounds between genetic and nongenetic influences. Quasi-experiments can be used to test hypotheses regarding environment exposure (e.g., timing, duration) while controlling for genetic confounds. To illustrate, two studies of cognitive self-regulation in childhood (i.e., working memory [WM], effortful control [EC], attention span/persistence [A/P]) are presented. Study 1 utilized an identical twin differences design ( N = 85 to 98 pairs) to control for genetic differences while using relative twin birth weight difference to predict relative twin difference in WM and EC. Larger relative twin difference in WM and EF was predicted by the combination of shorter gestation and larger relative birth weight difference. Study 2 utilized an adoptive sibling relative difference design ( N = 123 same-sex pairs) to control for genetic similarity while using relative sibling difference in the age at time of adoption to predict relative sibling difference in A/P. Larger relative sibling difference in A/P was predicted by the combination of larger relative difference in time in the adoptive home and age at adoption. Within-family quasi-experimental designs allow stronger inferences about hypothesized environmental influences than between-family designs permit.
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Park, Esther O; Park, Ji Hyun
2018-04-01
The effectiveness of flipped learning as one of the teaching methods of active learning has been left unexamined in nursing majors, compared to the frequent attempts to uncover the effectiveness of it in other disciplines. The purpose of this study was to reveal the effectiveness of flipped learning pedagogy in an adult health nursing course, controlling for other variables. The study applied a quasi-experimental approach, comparing pre- and post-test results in learning outcomes. Included in this analysis were the records of 81 junior nursing major students. The convenience sampling method was used to select the participants. Those in the experimental group were exposed to a flipped classroom experience that was given after the completion of their traditional class. The students' learning outcomes and the level of critical thinking skills were evaluated before and after the intervention of the flipped classroom. After the flipped classroom experience, the scores of the students' achievement in subject topics and critical thinking skills, specifically intellectual integrity and creativity, showed a greater level of increase than those of their controlled counterparts. This remained true even after controlling for previous academic performance and the level of creativity. This study confirmed the effectiveness of the flipped classroom as a measure of active learning by applying a quantitative approach. But, regarding the significance of the initial contribution of flipped learning in the discipline of nursing science, carrying out a more authentic experimental study could justify the impact of flipped learning pedagogy. © 2017 Japan Academy of Nursing Science.
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Sequential experimental design based generalised ANOVA
NASA Astrophysics Data System (ADS)
Chakraborty, Souvik; Chowdhury, Rajib
2016-07-01
Over the last decade, surrogate modelling technique has gained wide popularity in the field of uncertainty quantification, optimization, model exploration and sensitivity analysis. This approach relies on experimental design to generate training points and regression/interpolation for generating the surrogate. In this work, it is argued that conventional experimental design may render a surrogate model inefficient. In order to address this issue, this paper presents a novel distribution adaptive sequential experimental design (DA-SED). The proposed DA-SED has been coupled with a variant of generalised analysis of variance (G-ANOVA), developed by representing the component function using the generalised polynomial chaos expansion. Moreover, generalised analytical expressions for calculating the first two statistical moments of the response, which are utilized in predicting the probability of failure, have also been developed. The proposed approach has been utilized in predicting probability of failure of three structural mechanics problems. It is observed that the proposed approach yields accurate and computationally efficient estimate of the failure probability.
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Boal, Ashley L; Abroms, Lorien C; Simmens, Samuel; Graham, Amanda L; Carpenter, Kelly M
2016-05-01
This study seeks to determine whether comprehensive quitline services combined with text messaging improve smoking cessation rates beyond those achieved by offering comprehensive quitline services alone. The study sample consisted of callers to the Alere Wellbeing, Inc, commercial quitline in 2012. A quasi-experimental design was implemented using propensity score matching to create the intervention and control groups. The intervention group consisted of those who were offered and accepted a text message intervention in addition to usual quitline services, while the control group consisted of those who were not offered the text message intervention. Analyses utilized baseline data collected at intake, program use data (eg, call history and text message use), and reports of smoking behaviors and program satisfaction collected 6 months after intake. Similar rates of 7-day abstinence were reported regardless of whether participants received combined multi-call quitline services plus text messaging (25.3%) or multi-call quitline services in isolation (25.5%), though those who received combined services reported higher treatment satisfaction (P < .05). Among those who received combined services, the number of text messages sent to the text message program predicted 7-day abstinence such that those who sent more text messages were less likely to report 7-day abstinence. Text messaging may not confer additional benefits over and above those received through multi-modal, multi-call quitline programs. Future research should investigate whether text messaging programs improve quit rates when combined with less intensive services such as single-call phone counseling. While the impact of quitline and text messaging services for smoking cessation have been examined in isolation, no study has explored the impact of combined services on smoking outcomes. This study examines the role of text messaging in combination with comprehensive quitline services including multi-call phone
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Titanium-doped sapphire laser research and design study
NASA Technical Reports Server (NTRS)
Moulton, Peter F.
1987-01-01
Three main topics were considered in this study: the fundamental laser parameters of titanium-doped sapphire, characterization of commercially grown material, and design of a tunable, narrow-linewidth laser. Fundamental parameters investigated included the gain cross section, upper-state lifetime as a function of temperature and the surface-damage threshold. Commercial material was found to vary widely in the level of absorption of the laser wavelength with the highest absorption in Czochralski-grown crystals. Several Yi:sapphire lasers were constructed, including a multimode laser with greater than 50mJ of output energy and a single-transverse-mode ring laser, whose spectral and temporal characteristics were completely characterized. A design for a narrow-linewidth (single-frequency) Ti:sapphire laser was developed, based on the results of the experimental work. The design involves the use of a single-frequency, quasi-cw master oscillator, employed as an injection source for a pulsed ring laser.
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Webb, Michelle; Ronan, Kevin R
2014-10-01
A pilot study of an interactive hazards education program was carried out in Canberra (Australia), with direct input from youth participants. Effects were evaluated in relation to youths' interest in disasters, motivation to prepare, risk awareness, knowledge indicators, perceived preparedness levels, planning and practice for emergencies, and fear and anxiety indicators. Parents also provided ratings, including of actual home-based preparedness activities. Using a single group pretest-posttest with benchmarking design, a sample of 20 youths and their parents from a low SES community participated. Findings indicated beneficial changes on a number of indicators. Preparedness indicators increased significantly from pre- to posttest on both youth (p < 0.01) and parent ratings (p < 0.01). Parent ratings reflected an increase of just under six home-based preparedness activities. Youth knowledge about disaster mitigation also was seen to increase significantly (p < 0.001), increasing 39% from pretest levels. While personalized risk perceptions significantly increased (p < 0.01), anxiety and worry levels were seen either not to change (generalized anxiety, p > 0.05) or to reduce between pre- and posttest (hazards-specific fears, worry, and distress, ps ranged from p < 0.05 to < 0.001). In terms of predictors of preparedness, a number of variables were found to predict posttest preparedness levels, including information searching done by participants between education sessions. These pilot findings are the first to reflect quasi-experimental outcomes for a youth hazards education program carried out in a setting other than a school that focused on a sample of youth from a low SES community. © 2014 Society for Risk Analysis.
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Frequency-domain nonlinear optics in two-dimensionally patterned quasi-phase-matching media.
Phillips, C R; Mayer, B W; Gallmann, L; Keller, U
2016-07-11
Advances in the amplification and manipulation of ultrashort laser pulses have led to revolutions in several areas. Examples include chirped pulse amplification for generating high peak-power lasers, power-scalable amplification techniques, pulse shaping via modulation of spatially-dispersed laser pulses, and efficient frequency-mixing in quasi-phase-matched nonlinear crystals to access new spectral regions. In this work, we introduce and demonstrate a new platform for nonlinear optics which has the potential to combine these separate functionalities (pulse amplification, frequency transfer, and pulse shaping) into a single monolithic device that is bandwidth- and power-scalable. The approach is based on two-dimensional (2D) patterning of quasi-phase-matching (QPM) gratings combined with optical parametric interactions involving spatially dispersed laser pulses. Our proof of principle experiment demonstrates this technique via mid-infrared optical parametric chirped pulse amplification of few-cycle pulses. Additionally, we present a detailed theoretical and numerical analysis of such 2D-QPM devices and how they can be designed.
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Experimental Validation of an Integrated Controls-Structures Design Methodology
NASA Technical Reports Server (NTRS)
Maghami, Peiman G.; Gupta, Sandeep; Elliot, Kenny B.; Walz, Joseph E.
1996-01-01
The first experimental validation of an integrated controls-structures design methodology for a class of large order, flexible space structures is described. Integrated redesign of the controls-structures-interaction evolutionary model, a laboratory testbed at NASA Langley, was described earlier. The redesigned structure was fabricated, assembled in the laboratory, and experimentally tested against the original structure. Experimental results indicate that the structure redesigned using the integrated design methodology requires significantly less average control power than the nominal structure with control-optimized designs, while maintaining the required line-of-sight pointing performance. Thus, the superiority of the integrated design methodology over the conventional design approach is experimentally demonstrated. Furthermore, amenability of the integrated design structure to other control strategies is evaluated, both analytically and experimentally. Using Linear-Quadratic-Guassian optimal dissipative controllers, it is observed that the redesigned structure leads to significantly improved performance with alternate controllers as well.
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Does early paternal involvement predict offspring developmental diagnoses?
Jackson, Dylan B; Newsome, Jamie; Beaver, Kevin M
2016-12-01
A long line of research has illustrated that fathers play an important role in the development of their children. Few studies, however, have examined the impact of paternal involvement at the earliest stages of life on developmental diagnoses in childhood. The present study extends this line of research by exploring the possibility that paternal involvement prenatally, postnatally, and at the time of birth may influence offspring risk for various diagnoses in childhood. A quasi-experimental, propensity score matching design was used to create treatment and control groups to assess the relationship between paternal involvement at each stage of development and developmental diagnoses. Approximately 6000 children, and a subsample of fathers, who participated in the Early Childhood Longitudinal Study, Birth Cohort (ECLS-B). Activity, attention and learning, speech or language, and other diagnoses in early childhood, and overall number of diagnoses at 4years of age. We find no consistent evidence that low paternal involvement prenatally or postnatally increases the risk of various developmental diagnoses by age 4. However, children whose fathers were absent at the time of their birth were at significantly greater risk of incurring various developmental diagnoses, as well as a significantly greater number of developmental diagnoses. The findings expand our understanding of exactly how early paternal influence begins and the specific dimensions of early father behaviors that are related to the risk of various developmental diagnoses. Ultimately, these results have important implications concerning father involvement during the earliest stages of the life course. Copyright © 2016. Published by Elsevier Ireland Ltd.
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Shock-free turbomachinery blade design
NASA Technical Reports Server (NTRS)
Beauchamp, P. P.; Seebass, A. R.
1985-01-01
A computational method for designing shock-free, quasi-three-dimensional, transonic, turbomachinery blades is described. Shock-free designs are found by implementing Sobieczky's fictitious gas principle in the analysis of a baseline shape, resulting in an elliptic solution that is incorrect in the supersonic domain. Shock-free designs are obtained by combining the subsonic portion of this solution with a characteristic calculation of the correct supersonic flow using the sonic line data from the fictitious elliptic solution. This provides a new, shock-free blade design. Examples presented include the removal of shocks from two blades in quasi-three-dimensional flow and the development of a series of shock-free two-dimensional stators. The new designs all include modifications to the upper surface of an experimental stator blade developed at NASA Lewis Research Center. While the designs presented here are for inviscid flow, the same concepts have been successfully applied to the shock-free design of airfoils and three-dimensional wings with viscous effects. The extension of the present method to viscous flows is straightforward given a suitable analysis algorithm for the flow.
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Li, Huichu; Zhou, Lian; Wang, Cuicui; Chen, Renjie; Ma, Xiaoying; Xu, Bin; Xiong, Lilin; Ding, Zhen; Chen, Xiaodong; Zhou, Yun; Xu, Yan; Kan, Haidong
2017-06-15
There is increasing interest in quasi-experimental research to evaluate whether actions taken to improve air quality will benefit public health. We conducted a quasi-experimental study to evaluate inflammatory response to changes in air quality during the 2014 Nanjing Youth Olympics in China. We repeatedly measured 8 biomarkers of systemic inflammation in 31 healthy adults and obtained hourly air pollutant concentrations from a nearby fixed-site monitoring station. We used linear mixed-effect models to examine the associations between air quality changes and blood biomarkers. Air pollutant concentrations decreased apparently during the Youth Olympics. Concomitantly, we observed significant decreases in levels of soluble cluster of differentiation 40 (CD40) ligand and interleukin 1β (geometric means ratios were 0.45 and 0.24, respectively) from the pre-Olympic period to the intra-Olympic period. Afterwards, levels of C-reactive protein and vascular cell adhesion molecule 1 increased significantly (geometric means ratios were 2.22 and 1.29, respectively) in the post-Olympic period. Fine particulate matter and ozone were significantly associated with soluble CD40 ligand, P-selectin, interleukin 1β, intercellular adhesion molecule 1, and vascular cell adhesion molecule 1. Other pollutants showed positive but nonsignificant associations. Our study indicated that reduced air pollution, especially fine particulate matter and ozone, during the 2014 Nanjing Youth Olympics was associated with alleviated systemic inflammation in healthy adults. © The Author 2017. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
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NASA Astrophysics Data System (ADS)
Kowligy, Abijith S.; Lind, Alex; Hickstein, Daniel D.; Carlson, David R.; Timmers, Henry; Nader, Nima; Cruz, Flavio C.; Ycas, Gabriel; Papp, Scott B.; Diddams, Scott A.
2018-04-01
We experimentally demonstrate a simple configuration for mid-infrared (MIR) frequency comb generation in quasi-phase-matched lithium niobate waveguides using the cascaded-$\\chi^{(2)}$ nonlinearity. With nanojoule-scale pulses from an Er:fiber laser, we observe octave-spanning supercontinuum in the near-infrared with dispersive-wave generation in the 2.5--3 $\\text{\\mu}$m region and intra-pulse difference-frequency generation in the 4--5 $\\text{\\mu}$m region. By engineering the quasi-phase-matched grating profiles, tunable, narrow-band MIR and broadband MIR spectra are both observed in this geometry. Finally, we perform numerical modeling using a nonlinear envelope equation, which shows good quantitative agreement with the experiment---and can be used to inform waveguide designs to tailor the MIR frequency combs. Our results identify a path to a simple single-branch approach to mid-infrared frequency comb generation in a compact platform using commercial Er:fiber technology.
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Kowligy, Abijith S; Lind, Alex; Hickstein, Daniel D; Carlson, David R; Timmers, Henry; Nader, Nima; Cruz, Flavio C; Ycas, Gabriel; Papp, Scott B; Diddams, Scott A
2018-04-15
We experimentally demonstrate a simple configuration for mid-infrared (MIR) frequency comb generation in quasi-phase-matched lithium niobate waveguides using the cascaded-χ (2) nonlinearity. With nanojoule-scale pulses from an Er:fiber laser, we observe octave-spanning supercontinuum in the near-infrared with dispersive wave generation in the 2.5-3 μm region and intrapulse difference frequency generation in the 4-5 μm region. By engineering the quasi-phase-matched grating profiles, tunable, narrowband MIR and broadband MIR spectra are both observed in this geometry. Finally, we perform numerical modeling using a nonlinear envelope equation, which shows good quantitative agreement with the experiment-and can be used to inform waveguide designs to tailor the MIR frequency combs. Our results identify a path to a simple single-branch approach to mid-infrared frequency comb generation in a compact platform using commercial Er:fiber technology.
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Kobya Bulut, Hacer; Güdücü Tüfekci, Fatma
2016-12-01
There are numerous pharmacological and non-pharmacological treatment options available in the treatment of oral mucositis. However, in spite of so many methods and products, medical professionals have not come to a consensus as to which of these offer the best results. This study was conducted to assess the effect of oral care with honey on children undergoing chemotherapy for the prevention and healing of oral mucositis. This quasi-experimental study was conducted on children undergoing chemotherapy. The study group consisted of 83 children who attended clinics and polyclinics for chemotherapy. All the children were included in the study period. The study was completed with a total of 76 children except for seven patients who were excluded from the study. The data were collected using a form and the World Health Organization Mucositis Assessment Index. The data were analyzed using percentage distributions, means, a chi-square test, a t-test, a variance analysis, and a Friedman test. Ethics approval of the study was obtained from the Institution Ethics Committee. It was found that the severity of oral mucositis in the children in the experimental group was significantly less than the control group. The mucositis recovery period in the experimental group was significantly shorter than the control group. Regular oral care with honey for children undergoing chemotherapy for hematological cancers prevents mucositis and also accelerates recovery of it when started after mucositis onset. Copyright © 2016. Published by Elsevier Ltd.
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Poudel, Krishna C; Buchanan, David R; Poudel-Tandukar, Kalpana
2015-06-01
We evaluated the efficacy of a sexual risk reduction intervention utilizing protection motivation and social cognitive theories to address knowledge, threat and coping appraisals, and condom use intentions among HIV-positive individuals in Nepal. Using a quasi-experimental research design, we assigned 277 participants to intervention (n=146) and control (n=131) groups. The intervention group received six sessions on sexual risk reduction strategies and the control group six sessions on medication adherence, smoking, and mental health. Data were collected at baseline and immediately after the intervention. Results indicate that the sexual risk reduction intervention produced a significant increase in HIV transmission knowledge, perceived threat and coping appraisals, and intentions to use condoms with regular, HIV-positive, and HIV-negative partners. The positive effects of the intervention remained significant after adjusting for baseline scores and other potential confounders. In conclusion, our theory-based sexual risk reduction intervention was effective in improving HIV transmission knowledge, perceived threat and coping appraisals, and condom use intentions. Further studies are needed to evaluate the long-term efficacy of the intervention in increasing protection motivation and maintaining preventive behaviors.
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Regression Discontinuity Design: A Guide for Strengthening Causal Inference in HRD
ERIC Educational Resources Information Center
Chambers, Silvana
2016-01-01
Purpose: Regression discontinuity (RD) design is a sophisticated quasi-experimental approach used for inferring causal relationships and estimating treatment effects. This paper aims to educate human resource development (HRD) researchers and practitioners on the implementation of RD design as an ethical alternative for making causal claims about…
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Participatory Design, User Involvement and Health IT Evaluation.
Kushniruk, Andre; Nøhr, Christian
2016-01-01
End user involvement and input into the design and evaluation of information systems has been recognized as being a critical success factor in the adoption of information systems. Nowhere is this need more critical than in the design of health information systems. Consistent with evidence from the general software engineering literature, the degree of user input into design of complex systems has been identified as one of the most important factors in the success or failure of complex information systems. The participatory approach goes beyond user-centered design and co-operative design approaches to include end users as more active participants in design ideas and decision making. Proponents of participatory approaches argue for greater end user participation in both design and evaluative processes. Evidence regarding the effectiveness of increased user involvement in design is explored in this contribution in the context of health IT. The contribution will discuss several approaches to including users in design and evaluation. Challenges in IT evaluation during participatory design will be described and explored along with several case studies.
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Arsenolite: a quasi-hydrostatic solid pressure-transmitting medium.
Sans, J A; Manjón, F J; Popescu, C; Muñoz, A; Rodríguez-Hernández, P; Jordá, J L; Rey, F
2016-11-30
This study reports the experimental characterization of the hydrostatic properties of arsenolite (As4O6), a molecular solid which is one of the softest minerals in the absence of hydrogen bonding. The high compressibility of arsenolite and its stability up to 15 GPa have been proved by x-ray diffraction measurements, and the progressive loss of hydrostaticity with increasing pressure up to 20 GPa has been monitored by ruby photoluminescence. Arsenolite has been found to exhibit hydrostatic behavior up to 2.5 GPa and a quasi-hydrostatic behavior up to 10 GPa at room temperature. This result opens the way to explore other molecular solids as possible quasi-hydrostatic pressure-transmitting media. The validity of arsenolite as an insulating, stable, non-penetrating and quasi-hydrostatic medium is explored by the study of the x-ray diffraction of zeolite ITQ-29 at high pressure.
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Li, Jinghao; Hunt, John F; Gong, Shaoqin; Cai, Zhiyong
2017-01-01
This paper presents experimental results of both quasi-static compression and low-velocity impact behavior for tri-axial bio-composite structural panels using a spherical load head. Panels were made having different core and face configurations. The results showed that panels made having either carbon fiber fabric composite faces or a foam-filled core had significantly improved impact and compressive performance over panels without either. Different localized impact responses were observed based on the location of the compression or impact relative to the tri-axial structural core; the core with a smaller structural element had better impact performance. Furthermore, during the early contact phase for both quasi-static compression and low-velocity impact tests, the panels with the same configuration had similar load-displacement responses. The experimental results show basic compression data could be used for the future design and optimization of tri-axial bio-composite structural panels for potential impact applications. PMID:28772542
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The behavior of Aluminium Carbon/Epoxy fibre metal laminate under quasi-static loading
NASA Astrophysics Data System (ADS)
Romli, N. K.; Rejab, M. R. M.; Bachtiar, D.; Siregar, J.; Rani, M. F.; Harun, W. S. W.; Salleh, Salwani Mohd; Merzuki, M. N. M.
2017-10-01
One of major concerns that related to the flight safety is impact of birds. To minimize the risks, there is need to increase the impact resistance of aircraft by developing a new material and has the good structural design of aircraft structures. The hybrid laminates are potential candidate material to be applied for the aircraft structures susceptible to bird strikes. The fibre metal laminate was fabricated by a compression moulding technique. The carbon fibre and aluminium alloy 2024-0 was laminated by using thermoset epoxy. A compression moulding technique was used for the FML fabrication. The aluminium sheet metal has been roughening by a metal sanding method which to improve the bonding between the fibre and metal layer. The main objective of this paper is to determine the failure response of the laminate under five variations of the crosshead displacement in the quasi-static loading. The FML was modelled and analysed by using Explicit solver. Based on the experimental data of the quasi-static test, the result of 1 mm/min was 11.85 kN and higher than 5, 10, 50 and 100 mm/min which because of the aluminium ductility during the impact loading response. The numerical simulations were generally in good agreement with the experimental measurements.
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A Robust Adaptive Autonomous Approach to Optimal Experimental Design
NASA Astrophysics Data System (ADS)
Gu, Hairong
Experimentation is the fundamental tool of scientific inquiries to understand the laws governing the nature and human behaviors. Many complex real-world experimental scenarios, particularly in quest of prediction accuracy, often encounter difficulties to conduct experiments using an existing experimental procedure for the following two reasons. First, the existing experimental procedures require a parametric model to serve as the proxy of the latent data structure or data-generating mechanism at the beginning of an experiment. However, for those experimental scenarios of concern, a sound model is often unavailable before an experiment. Second, those experimental scenarios usually contain a large number of design variables, which potentially leads to a lengthy and costly data collection cycle. Incompetently, the existing experimental procedures are unable to optimize large-scale experiments so as to minimize the experimental length and cost. Facing the two challenges in those experimental scenarios, the aim of the present study is to develop a new experimental procedure that allows an experiment to be conducted without the assumption of a parametric model while still achieving satisfactory prediction, and performs optimization of experimental designs to improve the efficiency of an experiment. The new experimental procedure developed in the present study is named robust adaptive autonomous system (RAAS). RAAS is a procedure for sequential experiments composed of multiple experimental trials, which performs function estimation, variable selection, reverse prediction and design optimization on each trial. Directly addressing the challenges in those experimental scenarios of concern, function estimation and variable selection are performed by data-driven modeling methods to generate a predictive model from data collected during the course of an experiment, thus exempting the requirement of a parametric model at the beginning of an experiment; design optimization is
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Reed Johnson, F; Lancsar, Emily; Marshall, Deborah; Kilambi, Vikram; Mühlbacher, Axel; Regier, Dean A; Bresnahan, Brian W; Kanninen, Barbara; Bridges, John F P
2013-01-01
Stated-preference methods are a class of evaluation techniques for studying the preferences of patients and other stakeholders. While these methods span a variety of techniques, conjoint-analysis methods-and particularly discrete-choice experiments (DCEs)-have become the most frequently applied approach in health care in recent years. Experimental design is an important stage in the development of such methods, but establishing a consensus on standards is hampered by lack of understanding of available techniques and software. This report builds on the previous ISPOR Conjoint Analysis Task Force Report: Conjoint Analysis Applications in Health-A Checklist: A Report of the ISPOR Good Research Practices for Conjoint Analysis Task Force. This report aims to assist researchers specifically in evaluating alternative approaches to experimental design, a difficult and important element of successful DCEs. While this report does not endorse any specific approach, it does provide a guide for choosing an approach that is appropriate for a particular study. In particular, it provides an overview of the role of experimental designs for the successful implementation of the DCE approach in health care studies, and it provides researchers with an introduction to constructing experimental designs on the basis of study objectives and the statistical model researchers have selected for the study. The report outlines the theoretical requirements for designs that identify choice-model preference parameters and summarizes and compares a number of available approaches for constructing experimental designs. The task-force leadership group met via bimonthly teleconferences and in person at ISPOR meetings in the United States and Europe. An international group of experimental-design experts was consulted during this process to discuss existing approaches for experimental design and to review the task force's draft reports. In addition, ISPOR members contributed to developing a consensus
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The amount of ergonomics and user involvement in 151 design processes.
Kok, Barbara N E; Slegers, Karin; Vink, Peter
2012-01-01
Ergonomics, usability and user-centered design are terms that are well known among designers. Yet, products often seem to fail to meet the users' needs, resulting in a gap between expected and experienced usability. To understand the possible causes of this gap the actions taken by the designer during the design process are studied in this paper. This can show whether and how certain actions influence the user-friendliness of the design products. The aim of this research was to understand whether ergonomic principles and methods are included in the design process, whether users are involved in this process and whether the experience of the designer (in ergonomics/user involvement) has an effect on the end product usability. In this study the design processes of 151 tangible products of students in design were analyzed. It showed that in 75% of the cases some ergonomic principles were applied. User involvement was performed in only 1/3 of the design cases. Hardly any correlation was found between the designers' experience in ergonomic principles and the way they applied it and no correlations were found between the designers' experience in user involvement and the users' involvement in the design process.
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Quasi-kernel polynomials and convergence results for quasi-minimal residual iterations
NASA Technical Reports Server (NTRS)
Freund, Roland W.
1992-01-01
Recently, Freund and Nachtigal have proposed a novel polynominal-based iteration, the quasi-minimal residual algorithm (QMR), for solving general nonsingular non-Hermitian linear systems. Motivated by the QMR method, we have introduced the general concept of quasi-kernel polynomials, and we have shown that the QMR algorithm is based on a particular instance of quasi-kernel polynomials. In this paper, we continue our study of quasi-kernel polynomials. In particular, we derive bounds for the norms of quasi-kernel polynomials. These results are then applied to obtain convergence theorems both for the QMR method and for a transpose-free variant of QMR, the TFQMR algorithm.
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Sequential experimental design based generalised ANOVA
DOE Office of Scientific and Technical Information (OSTI.GOV)
Chakraborty, Souvik, E-mail: csouvik41@gmail.com; Chowdhury, Rajib, E-mail: rajibfce@iitr.ac.in
Over the last decade, surrogate modelling technique has gained wide popularity in the field of uncertainty quantification, optimization, model exploration and sensitivity analysis. This approach relies on experimental design to generate training points and regression/interpolation for generating the surrogate. In this work, it is argued that conventional experimental design may render a surrogate model inefficient. In order to address this issue, this paper presents a novel distribution adaptive sequential experimental design (DA-SED). The proposed DA-SED has been coupled with a variant of generalised analysis of variance (G-ANOVA), developed by representing the component function using the generalised polynomial chaos expansion. Moreover,more » generalised analytical expressions for calculating the first two statistical moments of the response, which are utilized in predicting the probability of failure, have also been developed. The proposed approach has been utilized in predicting probability of failure of three structural mechanics problems. It is observed that the proposed approach yields accurate and computationally efficient estimate of the failure probability.« less
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Carter, Eleanor; Whitworth, Adam
2015-04-01
'Creaming' and 'parking' are endemic concerns within quasi-marketised welfare-to-work (WTW) systems internationally, and the UK's flagship Work Programme for the long-term unemployed is something of an international pioneer of WTW delivery, based on outsourcing, payment by results and provider flexibility. In the Work Programme design, providers' incentives to 'cream' and 'park' differently positioned claimants are intended to be mitigated through the existence of nine payment groups (based on claimants' prior benefit type) into which different claimants are allocated and across which job outcome payments for providers differ. Evaluation evidence suggests however that 'creaming' and 'parking' practices remain common. This paper offers original quantitative insights into the extent of claimant variation within these payment groups, which, contrary to the government's intention, seem more likely to design in rather than design out 'creaming' and 'parking'. In response, a statistical approach to differential payment setting is explored and is shown to be a viable and more effective way to design a set of alternative and empirically grounded payment groups, offering greater predictive power and value-for-money than is the case in the current Work Programme design.
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Azizan, Azilyana; Justine, Maria
2016-02-01
Sedentary behavior and low participation in exercise among older adults can lead to depression and low quality of life (QOL). The current study investigated the effects of behavioral and exercise programs on depression severity and QOL among Malaysian community-dwelling older adults. A controlled, quasi-experimental, pre-posttest design was used. A total of 63 participants were divided into three groups: (a) exercise and behavior group (EBG), (b) exercise only group (EG), and (c) control group (CG). Results showed a significant difference in depression among groups (F(2,58) = 33.49, p < 0.01, η(2) = 0.54; mean, EBG < EG < CG) and in physical (F(2,58) = 5.33, p < 0.01, η(2)= 0.16; mean, EBG > EG > CG) and mental (F(2,58) = 4.08, p < 0.01, η(2) = 0.12; mean, EBG > CG > EG) scores of QOL. A combination of behavioral and exercise programs has superior effects on depression and QOL of older adults. [Journal of Gerontological Nursing, 42(2), 45-54.]. Copyright 2016, SLACK Incorporated.
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Effect Sizes in Cluster-Randomized Designs
ERIC Educational Resources Information Center
Hedges, Larry V.
2007-01-01
Multisite research designs involving cluster randomization are becoming increasingly important in educational and behavioral research. Researchers would like to compute effect size indexes based on the standardized mean difference to compare the results of cluster-randomized studies (and corresponding quasi-experiments) with other studies and to…
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Blagosklonny, Mikhail V
2013-06-15
If life were created by intelligent design, we would indeed age from accumulation of molecular damage. Repair is costly and limited by energetic resources, and we would allocate resources rationally. But, albeit elegant, this design is fictional. Instead, nature blindly selects for short-term benefits of robust developmental growth. "Quasi-programmed" by the blind watchmaker, aging is a wasteful and aimless continuation of developmental growth, driven by nutrient-sensing, growth-promoting signaling pathways such as MTOR (mechanistic target of rapamycin). A continuous post-developmental activity of such gerogenic pathways leads to hyperfunctions (aging), loss of homeostasis, age-related diseases, non-random organ damage and death. This model is consistent with a view that (1) soma is disposable, (2) aging and menopause are not programmed and (3) accumulation of random molecular damage is not a cause of aging as we know it.
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ERIC Educational Resources Information Center
Ogbuanya, T. C.; Owodunni, A. S.
2015-01-01
This study was designed to determine the effect of reflective inquiry instructional technique on achievement of students in Technical Colleges. The study adopted a pre-test, post-test, non-equivalent control group, quasi-experimental research design which involved groups of students in their intact class assigned to experimental group and control…
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NASA Astrophysics Data System (ADS)
Volkov, L. V.; Larkin, A. I.
1994-04-01
Theoretical and experimental investigations are reported of the potential applications of quasi-cw partially coherent radiation in optical systems based on diffraction—interference principles. It is shown that the spectral characteristics of quasi-cw radiation influence the data-handling capabilities of a holographic correlator and of a partially coherent holographic system for data acquisition. Relevant experimental results are reported.
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Quasi-independence, fitness, and advantageousness.
Brosnan, Kevin
2009-09-01
I argue that the idea of 'quasi-independence' [Lewontin, R. C. (1978). Adaptation. Scientific American, 239(3), 212-230] cannot be understood without attending to the distinction between fitness and advantageousness [Sober, E. (1993). Philosophy of biology. Boulder: Westview Press]. Natural selection increases the frequency of fitter traits, not necessarily of advantageous ones. A positive correlation between an advantageous trait and a disadvantageous one may prevent the advantageous trait from evolving. The quasi-independence criterion is aimed at specifying the conditions under which advantageous traits will evolve by natural selection in this type of situation. Contrary to what others have argued [Sterelny, K. (1992). Evolutionary explanations of human behavior. Australian Journal of Philosophy, 70(2), 156-172, and Sterelny, K., & Griffiths, P. (1999). Sex and death. Chicago: University of Chicago Press], these conditions must involve a precise quantitative measure of (a) the extent to which advantageous traits are beneficial, and (b) the degree to which they are correlated with other traits. Driscoll (2004) [Driscoll, C. (2004). Can behaviors be adaptations? Philosophy of Science, 71, 16-35] recognizes the need for such a measure, but I argue that she does not provide the correct formulation. The account of quasi-independence that I offer clarifies this point.
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How an Integrative STEM Curriculum Can Benefit Students in Engineering Design Practices
ERIC Educational Resources Information Center
Fan, Szu-Chun; Yu, Kuang-Chao
2017-01-01
STEM-oriented engineering design practice has become recognized increasingly by technology education professionals in Taiwan. This study sought to examine the effectiveness of the application of an integrative STEM approach within engineering design practices in high school technology education in Taiwan. A quasi-experimental study was conducted…
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Rotating of low-refractive-index microparticles with a quasi-perfect optical vortex.
Liang, Yansheng; Lei, Ming; Yan, Shaohui; Li, Manman; Cai, Yanan; Wang, Zhaojun; Yu, Xianghua; Yao, Baoli
2018-01-01
Low-refractive-index microparticles, such as hollow microspheres, have shown great significance in some applications, such as biomedical sensing and targeted drug delivery. However, optical trapping and manipulation of low-refractive-index microparticles are challenging, owing to the repelling force exerted by typical optical traps. In this paper, we demonstrated optical trapping and rotating of large-sized low-refractive-index microparticles by using quasi-perfect optical vortex (quasi-POV) beams, which were generated by Fourier transform of high-order quasi-Bessel beams. Numerical simulation was carried out to characterize the focusing property of the quasi-POV beams. The dynamics of low-refractive-index microparticles in the quasi-POV with various topological charges was investigated in detail. To improve the trapping and rotating performances of the vortex, a point trap was introduced at the center of the ring. Experimental results showed that the quasi-POV was preferable for manipulation of large-sized low-refractive-index microparticles, with its control of the particles' rotating velocity dependent only on the topological charge due to the unchanged orbital radius.
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Vázquez, María-Luisa; Vargas, Ingrid; Unger, Jean-Pierre; De Paepe, Pierre; Mogollón-Pérez, Amparo Susana; Samico, Isabella; Albuquerque, Paulette; Eguiguren, Pamela; Cisneros, Angelica Ivonne; Rovere, Mario; Bertolotto, Fernando
2015-07-31
Although fragmentation in the provision of healthcare is considered an important obstacle to effective care, there is scant evidence on best practices in care coordination in Latin America. The aim is to evaluate the effectiveness of a participatory shared care strategy in improving coordination across care levels and related care quality, in health services networks in six different healthcare systems of Latin America. A controlled before and after quasi-experimental study taking a participatory action research approach. In each country, two comparable healthcare networks were selected--intervention and control. The study contains four phases: (1) A baseline study to establish network performance in care coordination and continuity across care levels, using (A) qualitative methods: semi-structured interviews and focus groups with a criterion sample of health managers, professionals and users; and (B) quantitative methods: two questionnaire surveys with samples of 174 primary and secondary care physicians and 392 users with chronic conditions per network. Sample size was calculated to detect a proportion difference of 15% and 10%, before and after intervention (α=0.05; β=0.2 in a two-sided test); (2) a bottom-up participatory design and implementation of shared care strategies involving micro-level care coordination interventions to improve the adequacy of patient referral and information transfer. Strategies are selected through a participatory process by the local steering committee (local policymakers, health care network professionals, managers, users and researchers), supported by appropriate training; (3) Evaluation of the effectiveness of interventions by measuring changes in levels of care coordination and continuity 18 months after implementation, applying the same design as in the baseline study; (4) Cross-country comparative analysis. This study complies with international and national legal stipulations on ethics. Conditions of the study procedure
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NASA Astrophysics Data System (ADS)
Thomas, Philipp; Straube, Arthur V.; Grima, Ramon
2011-11-01
It is commonly believed that, whenever timescale separation holds, the predictions of reduced chemical master equations obtained using the stochastic quasi-steady-state approximation are in very good agreement with the predictions of the full master equations. We use the linear noise approximation to obtain a simple formula for the relative error between the predictions of the two master equations for the Michaelis-Menten reaction with substrate input. The reduced approach is predicted to overestimate the variance of the substrate concentration fluctuations by as much as 30%. The theoretical results are validated by stochastic simulations using experimental parameter values for enzymes involved in proteolysis, gluconeogenesis, and fermentation.
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Yazici, Gulay; Bulut, Hulya
2018-02-01
Healthcare-associated infections extend hospitalization time, increase treatment costs and increase morbidity-mortality rates. To evaluate the efficacy of a care bundle aimed at preventing three most frequent intensive care unit-acquired infections. This quasi-experimental study occurred in an 18-bed tertiary care intensive care unit at a university hospital in Turkey. The sample consisted of 120 patients older than 18years and receiving invasive mechanical ventilation therapy, or had a central venous catheter or urinary catheter. The study comprised three stages. In stage one, the intensive care unit nurses were trained in infection measures, VAP, CA-UTIs and CLABSIs sections of the care bundle. In stage two, the trained nurses applied the care bundle and received feedback on any problematic issues. In stage three, the nurses' compatibility and efficacy of the infection prevention care bundle on the infection rates of VAP, CA-UTIs and CLABSIs were evaluated over three 3-month periods. Over 1000 ventilation days, ventilator-associated pneumonia infection rates were 23.4, 12.6, and 11.5, during January-March, April-June and July-September, respectively, with January-March and April-June showing a significant decrease (χ 2 =6.934, p=0.031). The central line-associated bloodstream infection rates were 8.9, 4.2, and 9.9 per 1000 catheter days, during January-March, April-June and July-September, respectively, but were not significantly different based on pair-wise comparisons (p>0.05). The catheter-associated urinary tract infection rates were higher during July-September (6.7/1000 catheter days) compared to January-March (5.7/1000 catheter days) and April-June (10.4/1000 catheter days) but the differences were not significant (p>0.05). The infection rates decreased with increased compatibility of the care bundle prepared from evidence-based guidelines. Copyright © 2017 Elsevier Inc. All rights reserved.
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Teachers' Self-Regulated Learning Lesson Design: Integrating Learning from Problems and Successes
ERIC Educational Resources Information Center
Michalsky, Tova; Schechter, Chen
2018-01-01
Teachers' design of a lesson is critical for helping their students develop academically effective forms of self-regulating learning (SRL) in classrooms. Using a quasi-experimental design, the researchers integrated systematic collaborative learning from problematic and successful experiences into teachers' preparatory programs and examined how…
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Power Analysis Tutorial for Experimental Design Software
2014-11-01
I N S T I T U T E F O R D E F E N S E A N A L Y S E S IDA Document D-5205 November 2014 Power Analysis Tutorial for Experimental Design Software...16) [Jun 2013]. I N S T I T U T E F O R D E F E N S E A N A L Y S E S IDA Document D-5205 Power Analysis Tutorial for Experimental Design ...Test and Evaluation (T&E) community is increasing its employment of Design of Experiments (DOE), a rigorous methodology for planning and evaluating
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Improving knowledge of garlic paste greening through the design of an experimental strategy.
Aguilar, Miguel; Rincón, Francisco
2007-12-12
The furthering of scientific knowledge depends in part upon the reproducibility of experimental results. When experimental conditions are not set with sufficient precision, the resulting background noise often leads to poorly reproduced and even faulty experiments. An example of the catastrophic consequences of this background noise can be found in the design of strategies for the development of solutions aimed at preventing garlic paste greening, where reported results are contradictory. To avoid such consequences, this paper presents a two-step strategy based on the concept of experimental design. In the first step, the critical factors inherent to the problem are identified, using a 2(III)(7-4) Plackett-Burman experimental design, from a list of seven apparent critical factors (ACF); subsequently, the critical factors thus identified are considered as the factors to be optimized (FO), and optimization is performed using a Box and Wilson experimental design to identify the stationary point of the system. Optimal conditions for preventing garlic greening are examined after analysis of the complex process of green-pigment development, which involves both chemical and enzymatic reactions and is strongly influenced by pH, with an overall pH optimum of 4.5. The critical step in the greening process is the synthesis of thiosulfinates (allicin) from cysteine sulfoxides (alliin). Cysteine inhibits the greening process at this critical stage; no greening precursors are formed in the presence of around 1% cysteine. However, the optimal conditions for greening prevention are very sensitive both to the type of garlic and to manufacturing conditions. This suggests that optimal solutions for garlic greening prevention should be sought on a case-by-case basis, using the strategy presented here.
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Teacher Involvement in Curriculum Design: Need for Support to Enhance Teachers' Design Expertise
ERIC Educational Resources Information Center
Huizinga, Tjark; Handelzalts, Adam; Nieveen, Nienke; Voogt, Joke M.
2014-01-01
Teacher involvement in curriculum design has a long tradition. However, although it fosters implementation of curriculum reforms, teachers encounter various problems while designing related to conditions set for the design process, and lack the knowledge and skills needed to enact collaborative design processes. Providing support to enhance…
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Azmat, Syed Khurram; Khurram Azmat, Syed; Shaikh, Babar Tasneem; Tasneem Shaikh, Babar; Hameed, Waqas; Mustafa, Ghulam; Hussain, Wajahat; Asghar, Jamshaid; Ishaque, Muhammad; Ahmed, Aftab; Bilgrami, Mohsina
2013-01-01
Pakistan has had a low contraceptive prevalence rate for the last two decades; with preference for natural birth spacing methods and condoms. Family planning services offered by the public sector have never fulfilled the demand for contraception, particularly in rural areas. In the private sector, cost is a major constraint. In 2008, Marie Stopes Society - a local NGO started a social franchise programme along with a free voucher scheme to promote uptake of IUCDs amongst the poor. This paper evaluates the effectiveness of this approach, which is designed to increase modern long term contraceptive awareness and use in rural areas of Pakistan. We used a quasi-experimental study design with controls, selecting one intervention district and one control district from the Sindh and Punjab provinces. In each district, we chose a total of four service providers. A baseline survey was carried out among 4,992 married women of reproductive age (MWRA) in February 2009. Eighteen months after the start of intervention, an independent endline survey was conducted among 4,003 women. We used multilevel logistic regression for analysis using Stata 11. Social franchising used alongside free vouchers for long term contraceptive choices significantly increased the awareness of modern contraception. Awareness increased by 5% in the intervention district. Similarly, the ever use of modern contraceptive increased by 28.5%, and the overall contraceptive prevalence rate increased by 19.6%. A significant change (11.1%) was recorded in the uptake of IUCDs, which were being promoted with vouchers. Family planning franchise model promotes awareness and uptake of contraceptives. Moreover, supplemented with vouchers, it may enhance the use of IUCDs, which have a significant cost attached. Our research also supports a multi-pronged approach- generating demand through counselling, overcoming financial constraints by offering vouchers, training, accreditation and branding of the service providers
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Khurram Azmat, Syed; Tasneem Shaikh, Babar; Hameed, Waqas; Mustafa, Ghulam; Hussain, Wajahat; Asghar, Jamshaid; Ishaque, Muhammad; Ahmed, Aftab; Bilgrami, Mohsina
2013-01-01
Background Pakistan has had a low contraceptive prevalence rate for the last two decades; with preference for natural birth spacing methods and condoms. Family planning services offered by the public sector have never fulfilled the demand for contraception, particularly in rural areas. In the private sector, cost is a major constraint. In 2008, Marie Stopes Society – a local NGO started a social franchise programme along with a free voucher scheme to promote uptake of IUCDs amongst the poor. This paper evaluates the effectiveness of this approach, which is designed to increase modern long term contraceptive awareness and use in rural areas of Pakistan. Methodology We used a quasi-experimental study design with controls, selecting one intervention district and one control district from the Sindh and Punjab provinces. In each district, we chose a total of four service providers. A baseline survey was carried out among 4,992 married women of reproductive age (MWRA) in February 2009. Eighteen months after the start of intervention, an independent endline survey was conducted among 4,003 women. We used multilevel logistic regression for analysis using Stata 11. Results Social franchising used alongside free vouchers for long term contraceptive choices significantly increased the awareness of modern contraception. Awareness increased by 5% in the intervention district. Similarly, the ever use of modern contraceptive increased by 28.5%, and the overall contraceptive prevalence rate increased by 19.6%. A significant change (11.1%) was recorded in the uptake of IUCDs, which were being promoted with vouchers. Conclusion Family planning franchise model promotes awareness and uptake of contraceptives. Moreover, supplemented with vouchers, it may enhance the use of IUCDs, which have a significant cost attached. Our research also supports a multi-pronged approach- generating demand through counselling, overcoming financial constraints by offering vouchers, training
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Practical Techniques for Implementing True Experimental Designs.
ERIC Educational Resources Information Center
Powers, Donald E.; Alderman, Donald L.
1979-01-01
Practical methods for implementing true experimental designs in evaluation settings in which such designs are rarely used are presented. Particular attention is paid to educational settings. (Author/JKS)
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May Stakeholders be Involved in Design Without Informed Consent? The Case of Hidden Design.
Pols, A J K
2017-06-01
Stakeholder involvement in design is desirable from both a practical and an ethical point of view. It is difficult to do well, however, and some problems recur again and again, both of a practical nature, e.g. stakeholders acting strategically rather than openly, and of an ethical nature, e.g. power imbalances unduly affecting the outcome of the process. Hidden Design has been proposed as a method to deal with the practical problems of stakeholder involvement. It aims to do so by taking the observation of stakeholder actions, rather than the outcomes of a deliberative process, as its input. Furthermore, it hides from stakeholders the fact that a design process is taking place so that they will not behave differently than they otherwise would. Both aspects of Hidden Design have raised ethical worries. In this paper I make an ethical analysis of what it means for a design process to leave participants uninformed or deceived rather than acquiring their informed consent beforehand, and to use observation of actions rather than deliberation as input for design, using Hidden Design as a case study. This analysis is based on two sets of normative guidelines: the ethical guidelines for psychological research involving deception or uninformed participants from two professional psychological organisations, and Habermasian norms for a fair and just (deliberative) process. It supports the conclusion that stakeholder involvement in design organised in this way can be ethically acceptable, though under a number of conditions and constraints.
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Systematic Experimental Designs For Mixed-species Plantings
Jeffery C. Goelz
2001-01-01
Systematic experimental designs provide splendid demonstration areas for scientists and land managers to observe the effects of a gradient of species composition. Systematic designs are based on large plots where species composition varies gradually. Systematic designs save considerable space and require many fewer seedlings than conventional mixture designs. One basic...
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Olomu, Adesuwa; Hart-Davidson, William; Luo, Zhehui; Kelly-Blake, Karen; Holmes-Rovner, Margaret
2016-08-02
Use of Shared Decision-Making (SDM) and Decision Aids (DAs) has been encouraged but is not regularly implemented in primary care. The Office-Guidelines Applied to Practice (Office-GAP) intervention is an application of a previous model revised to address guidelines based care for low-income populations with diabetes and coronary heart disease (CHD). To evaluate Office-GAP Program feasibility and preliminary efficacy on medication use, patient satisfaction with physician communication and confidence in decision in low-income population with diabetes and coronary heart disease (CHD) in a Federally Qualified Healthcare Center (FQHC). Ninety-five patients participated in an Office-GAP program. A quasi-experimental design study, over 6 months with 12-month follow-up. Office-GAP program integrates health literacy, communication skills education for patients and physicians, patient/physician decision support tools and SDM into routine care. 1) Implementation rates of planned program elements 2) Patient satisfaction with communication and confidence in decision, and 3) Medication prescription rates. We used the GEE method for hierarchical logistic models, controlling for confounding. Feasibility of the Office-GAP program in the FQHC setting was established. We found significant increase in use of Aspirin/Plavix, statin and beta-blocker during follow-up compared to baseline: Aspirin OR 1.5 (95 % CI: 1.1, 2.2) at 3-months, 1.9 (1.3, 2.9) at 6-months, and 1.8 (1.2, 2.8) at 12-months. Statin OR 1.1 (1.0, 1.3) at 3-months and 1.5 (1.1, 2.2) at 12-months; beta-blocker 1.8 (1.1, 2.9) at 6-months and 12-months. Program elements were consistently used (≥ 98 % clinic attendance at training and tool used). Patient satisfaction with communication and confidence in decision increased. The use of Office-GAP program to teach SDM and use of DAs in real time was demonstrated to be feasible in FQHCs. It has the potential to improve satisfaction with physician communication and
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Integrated optical phased arrays for quasi-Bessel-beam generation.
Notaros, Jelena; Poulton, Christopher V; Byrd, Matthew J; Raval, Manan; Watts, Michael R
2017-09-01
Integrated optical phased arrays for generating quasi-Bessel beams are proposed and experimentally demonstrated in a CMOS-compatible platform. Owing to their elongated central beams, Bessel beams have applications in a range of fields, including multiparticle trapping and laser lithography. In this Letter, continuous Bessel theory is manipulated to formulate the phase and amplitude conditions necessary for generating free-space-propagating Bessel-Gauss beams using on-chip optical phased arrays. Discussion of the effects of select phased array parameters on the generated beam's figures of merit is included. A one-dimensional splitter-tree-based phased array architecture is modified to enable arbitrary passive control of the array's element phase and amplitude distributions. This architecture is used to experimentally demonstrate on-chip quasi-Bessel-beam generation with a ∼14 mm Bessel length and ∼30 μm power full width at half maximum.
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Rana, Monica; Gupta, Madhu; Malhi, Prahbhjot; Grover, Sandeep; Kaur, Manmeet
2018-02-05
Bullying perpetration and victimization is associated with significant academic, psychosocial and health related problems among adolescents. There is a need to develop effective interventions to prevent bullying among adolescents, especially in low and middle income countries. This paper presents the study protocol to develop, and evaluate the effect of multi-component school based prevention program for bullying in India. Quasi-experimental study. The study will be conducted among 846 students of grade 7 th and 8 th in the intervention and control schools in Chandigarh, Union Territory, North India. A government and a private school will be selected purposively in each of the intervention and control arm. The intervention is based on socio-ecological model, and will be administered at individual, relationship (parents and teachers) and school level. The primary study outcome will be the proportion of students experiencing any kind of bullying (bullying, victimization, or both), in each study arm. The effectiveness of the intervention will be measured by performing difference in difference analysis and generalized estimating equations. Bullying is an aggressive behaviour with significant morbidities, including psychological or physical trauma, affecting individuals not only in their adolescence, but also later in their adulthood. This quasi-experimental study is expected to provide evidence on whether multi-component bullying prevention intervention program, can reduce the burden of bullying perpetration and victimization among school adolescents in India. The results of the study will add in the exiting literature on bullying intervention program, especially, from the low middle-income countries, as there are limited studies available on this topic in these countries.
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Matar, Eman M; Arabiat, Diana H; Foster, Mandie J
2016-11-01
This research was undertaken with the purpose of testing two research hypotheses regarding the efficacy of 10% oral glucose solution on procedural pain associated with venepuncture and nasopharyngeal suctioning within three neonatal intensive care units (NICU). The hypotheses were formulated from previous conclusions reached by other researchers highlighting the efficacy of sucrose solutions on neonates' pain responses during minor painful procedures. A quasi-experimental trial utilising a time series design with one group was used. Data from a total of 90 neonates included 60 neonates who underwent a venepuncture and 30 neonates who underwent a nasopharyngeal suctioning procedure for clinical purposes. The neonate's pain response for each procedure was scored using the Neonatal Pain Assessment Scale (NPAS) on two separate occasions over three time periods. The pre-procedural score (T 0 ) when the neonate received no sucrose, the inter-procedural score (T 1 ) when the neonate was given 2ml of 10% glucose solution two minutes before the procedure (intervention group) or where oral glucose was withheld (control group) and the post-procedural score (T 2 ) being at the end of the procedure. The results showed the mean NPAS scores in response to venepuncture or nasopharyngeal suctioning were significantly lower in the intervention group than the control group. This showed that oral glucose (10%) had a positive effect on the pain response during venepuncture and nasopharyngeal suctioning procedures. Copyright © 2015 Elsevier Inc. All rights reserved.
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NASA Astrophysics Data System (ADS)
Zangori, Laura; Vo, Tina; Forbes, Cory T.; Schwarz, Christina V.
2017-07-01
Scientific modelling is a key practice in which K-12 students should engage to begin developing robust conceptual understanding of natural systems, including water. However, little past research has explored primary students' learning about groundwater, engagement in scientific modelling, and/or the ways in which teachers conceptualise and cultivate model-based science learning environments. We are engaged in a multi-year project designed to support 3rd-grade students' formulation of model-based explanations (MBE) for hydrologic phenomenon, including groundwater, through curricular and instructional support. In this quasi-experimental comparative study of five 3rd-grade classrooms, we present findings from analysis of students' MBE generated as part of experiencing a baseline curricular intervention (Year 1) and a modelling-enhanced curricular intervention (Year 2). Findings show that students experiencing the latter version of the unit made significant gains in both conceptual understanding and reasoning about groundwater, but that these gains varied by classroom. Overall, student gains from Year 1 to Year 2 were attributed to changes in two of the five classrooms in which students were provided additional instructional supports and scaffolds to enhance their MBE for groundwater. Within these two classrooms, the teachers enacted the Year 2 curriculum in unique ways that reflected their deeper understanding about the practices of modelling. Their enactments played a critical role in supporting students' MBE about groundwater. Study findings contribute to research on scientific modelling in elementary science learning environments and have important implications for teachers and curriculum developers.
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NASA Astrophysics Data System (ADS)
He, Da-Ren; Wang, Xu-Ming; Wang, Ying-Mei; Wang, Wen-Xiu; Chen, He-Sheng
2002-03-01
A kind of discontinuous and noninvertible area-preserving maps can display behaviors as a dissipative one, so it may be addressed as a "quasi-dissipative system"^1. In a quasi-dissipative system the disappearance of some elliptic periodic orbits and the elliptic islands around them via a collision with the discontinuous border of the system function can be observed. A chaotic quasi-attractor dominates behavior of the system after the disappearance of the elliptic periodic orbit and a sequence of transition elliptic periodic orbits. When the chaotic quasi-attractor just appears, the chaotic time sequence shows a random intersperse between laminar and turbulence phases. All these are very similar to the properties of type V intermittency happened in a dissipative system. So, we may call the phenomenon as a "type V quasi-intermittency". However, there can be only some remnants of the last disappeared transition elliptic island instead of its "ghost", therefore type V quasi-intermittency does not obey the characteristic scaling laws of type V intermittency. ^1 J. Wang et al., Phys.Rev.E, 64(2001)026202.
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Experimental toxicology: Issues of statistics, experimental design, and replication.
Briner, Wayne; Kirwan, Jeral
2017-01-01
The difficulty of replicating experiments has drawn considerable attention. Issues with replication occur for a variety of reasons ranging from experimental design to laboratory errors to inappropriate statistical analysis. Here we review a variety of guidelines for statistical analysis, design, and execution of experiments in toxicology. In general, replication can be improved by using hypothesis driven experiments with adequate sample sizes, randomization, and blind data collection techniques. Copyright © 2016 Elsevier B.V. All rights reserved.
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Chang, Shu-Fang; Hung, Chich-Hsiu; Hsu, Yu-Yun; Liu, Yi; Wang, Tsu-Nai
2017-08-01
Many studies have shown that providing health education before surgery may significantly increase health knowledge and decrease anxiety in both patients and their family members. However, few studies have compared the effects on pediatric outpatient surgery outcomes of different health education instruction modes. This study compares the effects of two health education delivery modes on maternal knowledge and anxiety, the number of unexpected early hospital follow-up visits, and the time spent by nurses on health education. A quasi-experimental design with pretest and posttest was used to compare the effect on the outcomes of pediatric circumcision of a multimedia compact disc (CD) and a printed material.Seventy mothers of children who underwent Plastibell circumcision participated in this study. Both the printed material and the multimedia CD significantly increased the knowledge and reduced the anxiety levels of the participants. However, no significant differences in unscheduled early hospital follow-up visits postsurgery were found between the two modes of instruction. Furthermore, we found that significantly fewer hours were spent by nurses on health education for the multimedia CD group in comparison with the printed material group. In the current clinical environment of common staffing shortages, information tools may be used to cost-effectively assist and simplify nursing work. The findings of this study may provide a reference to medical centers that are working to reduce the time spent by nurses on health education for outpatient surgery patients. Furthermore, audiovisual health education tools are recommended to increase nursing effectiveness and save nursing time.
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Rowe, Heather; Sperlich, Mickey; Seng, Julia S.
2015-01-01
Objective To test the effectiveness of a trauma-specific psycho-educational intervention for pregnant women with a history of childhood maltreatment on six intrapartum and postpartum psychological outcomes. Design Quasi-experimental study comparing women from a single-group pretest-posttest pilot intervention study with women matched from a prospective observational study. Setting Rural and university-based prenatal clinics. Participants Pregnant women entered the study by responding to an advertisement or by referral from a maternity care provider. Women could take part whether or not they met posttraumatic stress disorder diagnostic criteria. Outcomes data exist for 17 pilot intervention study participants and 43 matched observational study participants. Interventions Participants in the observational study received usual care. Participants in the pilot intervention study received usual care plus the intervention, a fully manualized self-study program supported by weekly phone tutoring sessions with a health professional. Main Outcome Measures The National Women’s Study PTSD Module; The Peritraumatic Dissociation Experience Questionnaire); The Perception of Care Questionnaire; The Postpartum Depression Screening Scale; The Postpartum Bonding Questionnaire; and a semantic differential appraisal of the labor experience. Results Participants in the intervention study had better scores on all measures. Differences in means between participants in the intervention study and participants in the observational study equated to medium effect sized for dissociation during labor, rating of labor experience, and perception of care in labor, and small effect sizes for postpartum PTSD symptoms, postpartum depression symptoms, and mother-infant bonding. Conclusion This trauma-specific intervention reaches and benefits pregnant women with a history of childhood maltreatment. PMID:24754455
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NASA Astrophysics Data System (ADS)
Abdullah, M.; Krishnan, Ganesan; Saliman, Tiffany; Fakaruddin Sidi Ahmad, M.; Bidin, Noriah
2018-03-01
A mirrorless refractometer was studied and analyzed using the quasi-Gaussian beam approach. The Fresnel equation for reflectivity at the interface between two mediums with different refractive indices was used to calculate the directional reflectivity, R. Various liquid samples from 1.3325 to 1.4657 refractive indices units were used. Experimentally, a fiber bundle probe with a concentric configuration of 16 receiving fibers and a single transmitting fiber was employed to verify the developed models. The sensor performance in term of sensitivity, linear range, and resolution, were analyzed and calculated. It has been shown that the developed theoretical models are capable of providing quantitative guidance of the output of the sensor with high accuracy. The highest resolution of the sensor was 4.39 × 10-3 refractive indices units, obtained by correlating the peak voltage along the refractive index. The resolution is sufficient for determining the specific refractive index increment of most polymer solutions, certain proteins, and also in monitoring bacterial growth. The accuracy, simplicity, and effectiveness of the proposed sensor over a long period of time while having non-contact measurements reflect a good potential for commercialization.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Pae, Ki Hong; Kim, Chul Min, E-mail: chulmin@gist.ac.kr; Advanced Photonics Research Institute, Gwangju Institute of Science and Technology, Gwangju 61005
In laser-driven proton acceleration, generation of quasi-monoenergetic proton beams has been considered a crucial feature of the radiation pressure acceleration (RPA) scheme, but the required difficult physical conditions have hampered its experimental realization. As a method to generate quasi-monoenergetic protons under experimentally viable conditions, we investigated using double-species targets of controlled composition ratio in order to make protons bunched in the phase space in the RPA scheme. From a modified optimum condition and three-dimensional particle-in-cell simulations, we showed by varying the ion composition ratio of proton and carbon that quasi-monoenergetic protons could be generated from ultrathin plane targets irradiated withmore » a circularly polarized Gaussian laser pulse. The proposed scheme should facilitate the experimental realization of ultrashort quasi-monoenergetic proton beams for unique applications in high field science.« less
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Vincent, Claude; Reinharz, Daniel; Deaudelin, Isabelle; Garceau, Mathieu; Talbot, Lise R
2006-07-07
Telesurveillance is a technologically based modality that allows the surveillance of patients in the natural setting, mainly home. It is based on communication technologies to relay information between a patient and a central call center where services are coordinated. Different types of telesurveillance systems have been implemented, some being staffed with non-health professionals and others with health professional, mainly nurses. Up to now, only telesurveillance services staffed with non-health professionals have been shown to be effective and efficient. The objective of this study was to document outcomes and cost evolution of a nurse-staffed telesurveillance system for frail elderly living at home. A quasi experimental design over a nine-month period was done. Patients (n = 38) and caregivers (n = 38) were selected by health professionals from two local community health centers. To be eligible, elders had to be over 65, live at home with a permanent physical, slight cognitive or motor disability or both and have a close relative (the caregiver) willing to participate to the study. These disabilities had to hinder the accomplishment of daily life activities deemed essential to continue living at home safely. Three data sources were used: patient files, telesurveillance center's quarterly reports and personal questionnaires (Modified Mini-Mental State, Functional Autonomy Measurement System, Life Event Checklist, SF-12, Life-H, Quebec User Evaluation of Satisfaction with Assistive Technology, Caregiver Burden). The telesurveillance technology permitted, among various functionalities, bi-directional communication (speaker-receiver) between the patient and the response center. A total of 957 calls for 38 registered clients over a 6-month period was recorded. Only 48 (5.0%) of the calls were health-related. No change was reported in the elders' quality of life and daily activity abilities. Satisfaction was very high. Caregivers' psychological burden decreased
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Designing Awe in Virtual Reality: An Experimental Study.
Chirico, Alice; Ferrise, Francesco; Cordella, Lorenzo; Gaggioli, Andrea
2017-01-01
Awe is a little-studied emotion with a great transformative potential. Therefore, the interest toward the study of awe's underlying mechanisms has been increased. Specifically, researchers have been interested in how to reproduce intense feelings of awe within laboratory conditions. It has been proposed that the use of virtual reality (VR) could be an effective way to induce awe in controlled experimental settings, thanks to its ability of providing participants with a sense of "presence," that is, the subjective feeling of being displaced in another physical or imaginary place. However, the potential of VR as awe-inducing medium has not been fully tested yet. In the present study, we provided an evidence-based design and a validation of four immersive virtual environments (VEs) involving 36 participants in a within-subject design. Of these, three VEs were designed to induce awe, whereas the fourth VE was targeted as an emotionally neutral stimulus. Participants self-reported the extent to which they felt awe, general affect and sense of presence related to each environment. As expected, results showed that awe-VEs could induce significantly higher levels of awe and presence as compared to the neutral VE. Furthermore, these VEs induced significantly more positive than negative affect. These findings supported the potential of immersive VR for inducing awe and provide useful indications for the design of awe-inspiring virtual environments.
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2016-08-01
quasi -static mechanical properties, deformation behavior, and damage mechanisms in HSHDC and compare the behavior with VHSC. 2. Develop experimental ...using the experimental setup described in Chapter 6. The quasi -static strain rate was approximately 10-4/s. All panels tested have nominal dimensions...ER D C TR -1 6- 13 Force Protection Basing; TeCD 1a Equipment and Protocols for Quasi -Static and Dynamic Tests of Very-High-Strength
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ERIC Educational Resources Information Center
Chan, Julia Y. K.; Bauer, Christopher F.
2015-01-01
This study investigated exam achievement and affective characteristics of students in general chemistry in a fully-randomized experimental design, contrasting Peer-Led Team Learning (PLTL) participation with a control group balanced for time-on-task and study activity. This study population included two independent first-semester courses with…
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Brinker, Titus J; Stamm-Balderjahn, Sabine; Seeger, Werner; Groneberg, David A
2014-07-24
A survey conducted by the German Federal Centre for Health Education in 2012 showed that 35.2% of all young adults (18-25 years) and 12.0% of all adolescents (12-17 years) in Germany are regular cigarette smokers. Most smoked their first cigarette in early adolescence. We recently reported a significantly positive short-term effect of a physician-delivered school-based smoking prevention programme on the smoking behaviour of schoolchildren in Germany. However, physician-based programmes are usually very expensive. Therefore, we will evaluate and optimise Education against Tobacco (EAT), a widespread, low-cost programme delivered by about 400 medical students from 16 universities in Germany. A prospective quasi-experimental study design with two measurements at baseline (t1) and 6 months post-intervention (t2) to investigate an intervention in 10-15-year-olds in grades 6-8 at German secondary schools. The intervention programme consists of two 60-min school-based medical-student-delivered modules with (module 1) and without the involvement of patients with tobacco-related diseases and control groups (no intervention). The study questionnaire measuring smoking status (water pipe and cigarette smoking), smoking-related cognitions, and gender, social and cultural aspects was designed and pre-tested in advance. The primary end point is the prevalence of smokers and non-smokers in the two study arms at 6 months after the intervention. The percentage of former smokers and new smokers in the two groups and the measures of smoking behaviour will be studied as secondary outcome measures. In accordance with Good Epidemiologic Practice (GEP) guidelines, the study protocol was submitted for approval by the responsible ethics committee, which decided that the study does not need ethical approval (Goethe University, Frankfurt-Main, Germany). Findings will be disseminated in peer-reviewed journals, at conferences, within our scientific advisory board and through medical
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Brinker, Titus J; Stamm-Balderjahn, Sabine; Seeger, Werner; Groneberg, David A
2014-01-01
Introduction A survey conducted by the German Federal Centre for Health Education in 2012 showed that 35.2% of all young adults (18–25 years) and 12.0% of all adolescents (12–17 years) in Germany are regular cigarette smokers. Most smoked their first cigarette in early adolescence. We recently reported a significantly positive short-term effect of a physician-delivered school-based smoking prevention programme on the smoking behaviour of schoolchildren in Germany. However, physician-based programmes are usually very expensive. Therefore, we will evaluate and optimise Education against Tobacco (EAT), a widespread, low-cost programme delivered by about 400 medical students from 16 universities in Germany. Methods and analysis A prospective quasi-experimental study design with two measurements at baseline (t1) and 6 months post-intervention (t2) to investigate an intervention in 10–15-year-olds in grades 6–8 at German secondary schools. The intervention programme consists of two 60-min school-based medical-student-delivered modules with (module 1) and without the involvement of patients with tobacco-related diseases and control groups (no intervention). The study questionnaire measuring smoking status (water pipe and cigarette smoking), smoking-related cognitions, and gender, social and cultural aspects was designed and pre-tested in advance. The primary end point is the prevalence of smokers and non-smokers in the two study arms at 6 months after the intervention. The percentage of former smokers and new smokers in the two groups and the measures of smoking behaviour will be studied as secondary outcome measures. Ethics and dissemination In accordance with Good Epidemiologic Practice (GEP) guidelines, the study protocol was submitted for approval by the responsible ethics committee, which decided that the study does not need ethical approval (Goethe University, Frankfurt-Main, Germany). Findings will be disseminated in peer-reviewed journals, at
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Al Mamun, Mahfuz; Parvin, Kausar; Yu, Marat; Wan, Jessica; Willan, Samantha; Gibbs, Andrew; Jewkes, Rachel; Naved, Ruchira Tabassum
2018-04-18
Women in Bangladesh experience high rates of Intimate Partner Violence (IPV). IPV is more prevalent against income earning women compared to their non-earning counterparts, and Workplace Violence (WPV) is also common. Such violence is a violation of women's rights, and also constrains them from contributing to their personal growth, household, community and the economy at large. There is limited evidence on what works to prevent IPV and WPV amongst garment workers. This paper describes an evaluation of HERrespect, an intervention which aims to reduce IPV and WPV against female garment workers in and around Dhaka, Bangladesh. The trial employs a quasi-experimental design, with four intervention and four control factories. In the intervention factories a randomly selected cohort of married female line workers, a cohort of male line workers, and all middle management staff received the intervention. The intervention strategies involved (1) gender transformative group-based training for workers and management staff; (2) joint session between workers (15 female and male) and middle-management staff; (3) factory-wide activities; (4) awareness raising among top management; (5) factory policy review and development and 6) a community based campaign. For the evaluation, a cohort of randomly selected female workers and a cohort of selected management staff have been established. All workers (n = 800) and management staff (n = 395) from these cohorts were interviewed at baseline using two different questionnaires, and will be interviewed in the endline, 24 months post-baseline. Intention to treat analysis will be used for assessing the impact of HERrespect, comparing the intervention and control factories. To our knowledge this is the first study that seeks to evaluate the impact on IPV and WPV, of group sessions with female workers, male workers, and management; factory-wide campaigns and a community intervention among female garment workers in Bangladesh. Apart
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Using Story Structure for Lesson Design in Teaching about Sexual Assault
ERIC Educational Resources Information Center
Erbe, Ryan G.; Kearns, Katherine D.
2016-01-01
The present pilot study examines the use of story structure for lesson design to promote student engagement in a lesson focusing on sexual assault prevention. The effect of the story-based lesson on undergraduates' knowledge and perceptions of sexual assault was studied using a quasi-experimental mixed methods design. Results of the study…
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How to Flip the Classroom--"Productive Failure or Traditional Flipped Classroom" Pedagogical Design?
ERIC Educational Resources Information Center
Song, Yanjie; Kapur, Manu
2017-01-01
The paper reports a quasi-experimental study comparing the "traditional flipped classroom" pedagogical design with the "productive failure" (Kapur, 2016) pedagogical design in the flipped classroom for a 2-week curricular unit on polynomials in a Hong Kong Secondary school. Different from the flipped classroom where students…
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Mateo-Ortega, Dolors; Gómez-Batiste, Xavier; Maté, Jorge; Beas, Elba; Ela, Sara; Lasmarias, Cristina; Limonero, Joaquín T
2018-03-13
To determine whether specific psychosocial interventions can ease discomfort in palliative care (PC) patients, particularly in those with high levels of pain or emotional distress. Changes in the psychological parameters of 8333 patients were assessed in a quasi-experimental, prospective, multicenter, single group pretest/post-test study. Psychosocial care was delivered by 29 psychosocial care teams (PSTs; 137 professionals). Pre- and post-intervention changes in these variables were assessed: mood, anxiety, and emotional distress. Patients were classified as complex, when presented with high levels of anxiety, mood, suffering (or perception of time as slow), and distress (or unease, or discomfort), or noncomplex. These groups were compared to assess changes in suffering-related parameters from baseline. Psychosocial interventions reduced patients' suffering. These interventions were more effective in complex patients. After successive psychosocial interventions, the level of suffering in complex patients decreased until close to parity with noncomplex patients, suggesting that patients with major complexity could benefit most from specific psychosocial treatment. These findings support the importance of assessing and treating patients' psychosocial needs.
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Drought Adaptation Mechanisms Should Guide Experimental Design.
Gilbert, Matthew E; Medina, Viviana
2016-08-01
The mechanism, or hypothesis, of how a plant might be adapted to drought should strongly influence experimental design. For instance, an experiment testing for water conservation should be distinct from a damage-tolerance evaluation. We define here four new, general mechanisms for plant adaptation to drought such that experiments can be more easily designed based upon the definitions. A series of experimental methods are suggested together with appropriate physiological measurements related to the drought adaptation mechanisms. The suggestion is made that the experimental manipulation should match the rate, length, and severity of soil water deficit (SWD) necessary to test the hypothesized type of drought adaptation mechanism. Copyright © 2016 Elsevier Ltd. All rights reserved.
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Autonomous entropy-based intelligent experimental design
NASA Astrophysics Data System (ADS)
Malakar, Nabin Kumar
2011-07-01
The aim of this thesis is to explore the application of probability and information theory in experimental design, and to do so in a way that combines what we know about inference and inquiry in a comprehensive and consistent manner. Present day scientific frontiers involve data collection at an ever-increasing rate. This requires that we find a way to collect the most relevant data in an automated fashion. By following the logic of the scientific method, we couple an inference engine with an inquiry engine to automate the iterative process of scientific learning. The inference engine involves Bayesian machine learning techniques to estimate model parameters based upon both prior information and previously collected data, while the inquiry engine implements data-driven exploration. By choosing an experiment whose distribution of expected results has the maximum entropy, the inquiry engine selects the experiment that maximizes the expected information gain. The coupled inference and inquiry engines constitute an autonomous learning method for scientific exploration. We apply it to a robotic arm to demonstrate the efficacy of the method. Optimizing inquiry involves searching for an experiment that promises, on average, to be maximally informative. If the set of potential experiments is described by many parameters, the search involves a high-dimensional entropy space. In such cases, a brute force search method will be slow and computationally expensive. We develop an entropy-based search algorithm, called nested entropy sampling, to select the most informative experiment. This helps to reduce the number of computations necessary to find the optimal experiment. We also extended the method of maximizing entropy, and developed a method of maximizing joint entropy so that it could be used as a principle of collaboration between two robots. This is a major achievement of this thesis, as it allows the information-based collaboration between two robotic units towards a same
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Musk as a Pheromone? Didactic Exercise.
ERIC Educational Resources Information Center
Bersted, Chris T.
A classroom/laboratory exercise has been used to introduce college students to factorial research designs, differentiate between interpretations for experimental and quasi-experimental variables, and exemplify application of laboratory research methods to test practical questions (advertising claims). The exercise involves having randomly divided…
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ERIC Educational Resources Information Center
Cattaneo, Matias D.; Titiunik, Rocío; Vazquez-Bare, Gonzalo
2017-01-01
The regression discontinuity (RD) design is a popular quasi-experimental design for causal inference and policy evaluation. The most common inference approaches in RD designs employ "flexible" parametric and nonparametric local polynomial methods, which rely on extrapolation and large-sample approximations of conditional expectations…
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ERIC Educational Resources Information Center
Venkateswarlu, P.
2017-01-01
Reforms in undergraduate engineering curriculum to produce engineers with entrepreneurial skills should address real-world problems relevant to industry and society with active industry support. Technology-assisted, hands-on projects involving experimentation, design simulation and prototyping will transform graduates into professionals with…
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DOE Office of Scientific and Technical Information (OSTI.GOV)
al-Wahish, Amal; Armitage, D.; al-Binni, U.
Our design for a sample cell system suitable for high temperature Quasi-Elastic Neutron Scattering (QENS) experiments is presented. The apparatus was developed at the Spallation Neutron Source in Oak Ridge National Lab where it is currently in use. The design provides a special sample cell environment under controlled humid or dry gas flow over a wide range of temperature up to 950°C. Using such a cell, chemical, dynamical, and physical changes can be studied in situ under various operating conditions. And while the cell combined with portable automated gas environment system is especially useful for in situ studies of microscopicmore » dynamics under operational conditions that are similar to those of solid oxide fuel cells, it can additionally be used to study a wide variety of materials, such as high temperature protonconductors. The cell can also be used in many different neutron experiments when a suitable sample holder material is selected. Finally, the sample cell system has recently been used to reveal fast dynamic processes in quasi-elastic neutron scattering experiments, which standard probes (such as electrochemical impedance spectroscopy) could not detect. In this work, we outline the design of the sample cell system and present results demonstrating its abilities in high temperature QENS experiments.« less
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al-Wahish, Amal; Armitage, D; al-Binni, U; Hill, B; Mills, R; Jalarvo, N; Santodonato, L; Herwig, K W; Mandrus, D
2015-09-01
A design for a sample cell system suitable for high temperature Quasi-Elastic Neutron Scattering (QENS) experiments is presented. The apparatus was developed at the Spallation Neutron Source in Oak Ridge National Lab where it is currently in use. The design provides a special sample cell environment under controlled humid or dry gas flow over a wide range of temperature up to 950 °C. Using such a cell, chemical, dynamical, and physical changes can be studied in situ under various operating conditions. While the cell combined with portable automated gas environment system is especially useful for in situ studies of microscopic dynamics under operational conditions that are similar to those of solid oxide fuel cells, it can additionally be used to study a wide variety of materials, such as high temperature proton conductors. The cell can also be used in many different neutron experiments when a suitable sample holder material is selected. The sample cell system has recently been used to reveal fast dynamic processes in quasi-elastic neutron scattering experiments, which standard probes (such as electrochemical impedance spectroscopy) could not detect. In this work, we outline the design of the sample cell system and present results demonstrating its abilities in high temperature QENS experiments.
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Zhang, Xiaopeng; Wang, Lijun; Zhang, Xinping
2014-11-11
Transparency has become a hottest topic and a growing movement in the health care system worldwide. This study used a quasi-experimental design method to explore whether public reporting of medicine use information can improve rational drug use. 20 township hospitals and 274 doctors of City Y in Hubei Province, China were divided into the intervention and control groups on the basis of their characteristics. In the intervention group, the values and rankings of the average expenditure per prescription, percentage of prescriptions requiring antibiotics and percentage of prescriptions requiring injections of each hospital and doctor were publicly released to patients and doctors in an appropriate format monthly. Data were gathered both four months before and after the intervention. Propensity score matching (PSM) was used to minimize the observed covariate (gender, age, experience, education level, title, and monthly income) differences in the doctors' characteristics. 108 pairs of doctors were obtained after PSM. Chi-square test and t-test were employed to explore the effect of public reporting of medicine use information on rational drug use. The study was approved by the Committee of Tongji Medical College, Hua Zhong University of Science and Technology (IORG No: IORG0003571). In baseline, the average expenditure per prescription of the 274 doctors was 42.82 RMB yuan (USD 6.97), the percentage of prescriptions requiring antibiotics was 63.00%, and the percentage of prescriptions requiring injections was 70.79%, all higher than the average of Hubei Province and the standard recommended by WHO. Before the intervention all the three indicators were all comparable (p > 0.05), whereas after the intervention, a significant difference (p < 0.05) was found for the percentage of prescriptions requiring injections between the intervention (64.66%) and control groups (70.52%). Irrational drug use remains a policy issue in township hospitals in the study area. We demonstrated
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Gilligan, Conor; Kypri, Kypros; Bourke, Jesse
2014-09-17
Increasingly, social contact and knowledge of other people's attitudes and behavior are mediated by online social media such as Facebook. The main research to which this recruitment study pertains investigates the influence of parents on adolescent alcohol consumption. Given the pervasiveness of online social media use, Facebook may be an effective means of recruitment and intervention delivery. The objective of the study was to determine the efficacy of study recruitment via social networks versus paid advertising on Facebook. We conducted a quasi-experimental sequential trial with response rate as the outcome, and estimates of cost-effectiveness. The target population was parents of 13-17 year old children attending high schools in the Hunter region of New South Wales, Australia. Recruitment occurred via: method (1) social recruitment using Facebook, email-based, social networks, and media coverage followed by method (2) Facebook advertising. Using a range of online and other social network approaches only: method (1) 74 parents were recruited to complete a survey over eight months, costing AUD58.70 per completed survey. After Facebook advertising: method (2) 204 parents completed the survey over four weeks, costing AUD5.94 per completed survey. Participants were representative of the parents recruited from the region's schools using standard mail and email. Facebook advertising is a cost-effective means of recruiting parents, a group difficult to reach by other methods.
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The Effect of New Shower Facilities on Physical Activity Behaviors of Employees: A Quasi-experiment.
Nehme, Eileen K; Pérez, Adriana; Ranjit, Nalini; Amick, Benjamin C; Kohl, Harold W
2017-02-01
This quasi-experimental study assessed the effects of new workplace showers on physical activity behaviors in a sample of downtown employees in Austin, TX. The study design was quasi-experimental with 2 comparison groups. Data were collected via internet-based surveys before and 4 months after shower installation at 1 worksite. Differences across study groups in the ranks of change in past-week minutes of physical activity from baseline to follow-up were assessed. Adjusted odds ratios and 95% confidence intervals for reporting an increase of ≥10 min past-week physical activity and workday physical activity among those with new showers and existing showers relative to those with no showers were also assessed. No significant differences in changes in physical activity from baseline to follow-up across study groups were found. One-quarter of participants with new workplace showers and 46.9% of those with existing workplace showers at baseline reported ever using the showers. This prospective study did not find significant changes in employee physical activity 4 months after installation of worksite showers. Worksite shower users were highly active at baseline, suggesting a possible early adopter effect, with potential for diffusion. Future studies may benefit from longer exposure times and larger samples.
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ERIC Educational Resources Information Center
Howell, Robert E.; And Others
A model and supportive materials are presented for design and implementation of a program for involving citizens in decision-making concerning significant environmental issues. Chapter topics include: why citizen involvement? (potential benefits of the process); theoretical basis for citizen involvement (three fundamental perspectives underlying…
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White, Justin S; Hamad, Rita; Li, Xinjun; Basu, Sanjay; Ohlsson, Henrik; Sundquist, Jan; Sundquist, Kristina
2016-06-01
Although studies have shown associations between neighbourhood quality and chronic disease outcomes, such associations are potentially confounded by the selection of different types of people into different neighbourhood environments. We sought to identify the causal effects of neighbourhood deprivation on type 2 diabetes risk, by comparing refugees in Sweden who were actively dispersed by government policy to low-deprivation, moderate-deprivation, or high-deprivation neighbourhoods. In this quasi-experimental study, we analysed national register data for refugees who arrived in Sweden aged 25-50 years, at a time when the government policy involved quasi-random dispersal of refugees to neighbourhoods with different levels of poverty and unemployment, schooling, and social welfare participation. Individuals in our sample were assigned to a neighbourhood categorised as high deprivation (≥1 SD above the mean), moderate deprivation (within 1 SD of the mean), or low deprivation (≥1 SD below the mean). The primary outcome was new diagnosis of type 2 diabetes between Jan 1, 2002, and Dec 31, 2010. We used multivariate logistic and linear regressions to assess the effects of neighbourhood deprivation on diabetes risk, controlling for potential confounders affecting neighbourhood assignment and assessing effects of cumulative exposure to different neighbourhood conditions. We included data for 61 386 refugees who arrived in Sweden during 1987-91 and who were assigned to one of 4833 neighbourhoods. Being assigned to an area deemed high deprivation versus low deprivation was associated with an increased risk of diabetes (odds ratio [OR] 1·22, 95% CI 1·07-1·38; p=0·001). In analyses that included fixed effects for assigned municipality, the increased diabetes risk was estimated to be 0·85 percentage points (95% CI -0·030 to 1·728; p=0·058). Neighbourhood effects grew over time such that 5 years of additional exposure to high-deprivation versus low
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Damage and fracture in fabric-reinforced composites under quasi-static and dynamic bending
NASA Astrophysics Data System (ADS)
Ullah, H.; Harland, A. R.; Silberschmidt, V. V.
2013-07-01
Fabric-reinforced polymer composites used in sports products can be exposed to different in-service conditions such as large deformations caused by quasi-static and dynamic loading. Composite materials subjected to such bending loads can demonstrate various damage modes - matrix cracking, delamination and, ultimately, fabric fracture. Damage evolution in composites affects both their in-service properties and performance that can deteriorate with time. Such behaviour needs adequate means of analysis and investigation, the main approaches being experimental characterisation and non-destructive examination of internal damage in composite laminates. This research deals with a deformation behaviour and damage in carbon fabric-reinforced polymer (CFRP) laminates caused by quasi-static and dynamic bending. Experimental tests were carried out to characterise the behaviour of a CFRP material under large-deflection bending, first in quasi-static and then in dynamic conditions. Izod-type impact bending tests were performed on un-notched specimens of CFRP using a Resil impactor to assess the transient response and energy absorbing capability of the material. X-ray micro computed tomography (micro-CT) was used to analyse various damage modes in the tested specimens. X-ray tomographs revealed that through-thickness matrix cracking, inter-ply and intra-ply delamination such as tow debonding, and fabric fracture were the prominent damage modes both in quasi-static and dynamic test specimens. However, the inter-ply damage was localised at impact location in dynamically tested specimens, whereas in the quasi-static specimens, it spread almost over the entire interface.
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Photoelectric-enhanced radiation therapy with quasi-monochromatic computed tomography
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jost, Gregor; Mensing, Tristan; Golfier, Sven
2009-06-15
Photoelectric-enhanced radiation therapy is a bimodal therapy, consisting of the administration of highly radiation-absorbing substances into the tumor area and localized regional irradiation with orthovoltage x-rays. Irradiation can be performed by a modified computed tomography (CT) unit equipped with an additional x-ray optical module which converts the polychromatic, fan-shaped CT beam into a monochromatized and focused beam for energy-tuned photoelectric-enhanced radiotherapy. A dedicated x-ray optical module designed for spatial collimation, focusing, and monochromatization was mounted at the exit of the x-ray tube of a clinical CT unit. Spectrally resolved measurements of the resulting beam were performed using an energy-dispersive detectionmore » system calibrated by synchrotron radiation. The spatial photon fluence was determined by film dosimetry. Depth-dose measurements were performed and compared to the polychromatic CT and a therapeutic 6 MV beam. The spatial dose distribution in phantoms using a rotating radiation source (quasi-monochromatic CT and 6 MV, respectively) was investigated by gel dosimetry. The photoelectric dose enhancement for an iodine fraction of 1% in tissue was calculated and verified experimentally. The x-ray optical module selectively filters the energy of the tungsten K{alpha} emission line with an FWHM of 5 keV. The relative photon fluence distribution demonstrates the focusing characteristic of the x-ray optical module. A beam width of about 3 mm was determined at the isocenter of the CT gantry. The depth-dose measurements resulted in a half-depth value of approximately 36 mm for the CT beams (quasi-monochromatic, polychromatic) compared to 154 mm for the 6 MV beam. The rotation of the radiation source leads to a steep dose gradient at the center of rotation; the gel dosimetry yields an entrance-to-peak dose ratio of 1:10.8 for the quasi-monochromatic CT and 1:37.3 for a 6 MV beam of the same size. The photoelectric dose
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Implementing a Critically Quasi-Ethnographic Approach
ERIC Educational Resources Information Center
Murtagh, Lisa
2007-01-01
This paper provides an account of the methodological approach of a study designed to address some fundamental questions relating to formative assessment. The paper reports on the use of a critically quasi-ethnographic approach and describes the practicalities of adopting such an approach. The validity of the study is also considered, reflecting on…
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Dhama, Rakesh; Caligiuri, Vincenzo; Petti, Lucia; Rashed, Alireza R; Rippa, Massimo; Lento, Raffaella; Termine, Roberto; Caglayan, Humeyra; De Luca, Antonio
2018-01-23
Plasmonic quasi-periodic structures are well-known to exhibit several surprising phenomena with respect to their periodic counterparts, due to their long-range order and higher rotational symmetry. Thanks to their specific geometrical arrangement, plasmonic quasi-crystals offer unique possibilities in tailoring the coupling and propagation of surface plasmons through their lattice, a scenario in which a plethora of fascinating phenomena can take place. In this paper we investigate the extraordinary transmission phenomenon occurring in specifically patterned Thue-Morse nanocavities, demonstrating noticeable enhanced transmission, directly revealed by near-field optical experiments, performed by means of a scanning near-field optical microscope (SNOM). SNOM further provides an intuitive picture of confined plasmon modes inside the nanocavities and confirms that localization of plasmon modes is based on size and depth of nanocavities, while cross talk between close cavities via propagating plasmons holds the polarization response of patterned quasi-crystals. Our performed numerical simulations are in good agreement with the experimental results. Thus, the control on cavity size and incident polarization can be used to alter the intensity and spatial properties of confined cavity modes in such structures, which can be exploited in order to design a plasmonic device with customized optical properties and desired functionalities, to be used for several applications in quantum plasmonics.
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Grahn Kronhed, Ann-Charlotte; Blomberg, Carina; Löfman, Owe; Timpka, Toomas; Möller, Margareta
2006-06-01
Osteoporosis and fall fractures are increasing problems amongst the elderly. The aim of this study was to explore whether combined population-based and individual interventions directed at risk factors for osteoporosis and falls result in behavioral changes in an elderly population. A quasi-experimental design was used for the study. Persons aged >or=65 years were randomly selected in the intervention and control community. An intervention program was managed from the primary health care center and delivered to the community. Health education was designed to increase awareness of risk factors for the development of osteoporosis and falling. Questionnaires about lifestyle, health, previous fractures, safety behavior and physical activity level were distributed at baseline in 1989 and at the follow-ups in 1992 and 1994 in both communities. There was a difference of 17.7% between the dual intervention (receiving both population-based and individual interventions) and the control samples regarding the self-reported use of shoe/cane spikes, and a difference of 20.5% regarding the reported "moderate level" of physical activity in 1994. There was an increase in the number of participants in the dual intervention sample who, at baseline, had not reported equipping their homes with non-slip mats and removing loose rugs but who did report these changes in 1994. The increase in the reported use of shoe/cane spikes in the dual intervention sample was observed mainly for the period 1992-1994. A public health intervention model, including both population-based and individual interventions, can contribute to behavioral changes in the prevention of falls and changed physical activity patterns amongst elderly people.
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False Dichotomies and Health Policy Research Designs: Randomized Trials Are Not Always the Answer.
Soumerai, Stephen B; Ceccarelli, Rachel; Koppel, Ross
2017-02-01
Some medical scientists argue that only data from randomized controlled trials (RCTs) are trustworthy. They claim data from natural experiments and administrative data sets are always spurious and cannot be used to evaluate health policies and other population-wide phenomena in the real world. While many acknowledge biases caused by poor study designs, in this article we argue that several valid designs using administrative data can produce strong findings, particularly the interrupted time series (ITS) design. Many policy studies neither permit nor require an RCT for cause-and-effect inference. Framing our arguments using Campbell and Stanley's classic research design monograph, we show that several "quasi-experimental" designs, especially interrupted time series (ITS), can estimate valid effects (or non-effects) of health interventions and policies as diverse as public insurance coverage, speed limits, hospital safety programs, drug abuse regulation and withdrawal of drugs from the market. We further note the recent rapid uptake of ITS and argue for expanded training in quasi-experimental designs in medical and graduate schools and in post-doctoral curricula.
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Quasi-symmetry and the nature of radial turbulent transport in quasi-poloidal stellarators
NASA Astrophysics Data System (ADS)
Alcuson, J. A.; Reynolds-Barredo, J. M.; Bustos, A.; Sanchez, R.; Tribaldos, V.; Xanthopoulos, P.; Goerler, T.; Newman, D. E.
2016-10-01
Quasi-symmetric configurations have a better neoclassical confinement compared to that of standard stellarators. The reduction of the neoclassical viscosity along the direction of quasi-symmetry should facilitate the self-generation of zonal flows and, consequently, the mitigation of turbulent fluctuations and the ensuing radial transport. Therefore, it is expected that quasi-symmetries should also result in better confinement properties regarding radial turbulent transport. In this paper we show that, at least for quasi-poloidal configurations, the influence of quasi-symmetry on radial transport exceeds the expected reduction of fluctuation levels and associated effective transport coefficients, and that the intimate nature of transport itself is affected. In particular, radial turbulent transport becomes increasingly subdiffusive as the degree of quasi-symmetry becomes larger. This behavior is somewhat reminiscent of what has been previously reported in tokamaks with strong radially sheared zonal flows.
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ERIC Educational Resources Information Center
de Anda, Diane
2007-01-01
This article discusses the difficulties in conducting intervention research or evaluating intervention programs in a school setting. In particular, the problems associated with randomization and obtaining control groups are examined. The use of quasi-experimental designs, specifically a paired comparison design using the individual as his or her…
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The Effects of Computer-Aided Design Software on Engineering Students' Spatial Visualisation Skills
ERIC Educational Resources Information Center
Kösa, Temel; Karakus, Fatih
2018-01-01
The purpose of this study was to determine the influence of computer-aided design (CAD) software-based instruction on the spatial visualisation skills of freshman engineering students in a computer-aided engineering drawing course. A quasi-experimental design was applied, using the Purdue Spatial Visualization Test-Visualization of Rotations…
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Recommendations for research design of telehealth studies.
Chumbler, Neale R; Kobb, Rita; Brennan, David M; Rabinowitz, Terry
2008-11-01
Properly designed randomized controlled trials (RCTs) are the gold standard to use when examining the effectiveness of telehealth interventions on clinical outcomes. Some published telehealth studies have employed well-designed RCTs. However, such methods are not always feasible and practical in particular settings. This white paper addresses not only the need for properly designed RCTs, but also offers alternative research designs, such as quasi-experimental designs, and statistical techniques that can be employed to rigorously assess the effectiveness of telehealth studies. This paper further offers design and measurement recommendations aimed at and relevant to administrative decision-makers, policymakers, and practicing clinicians.
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Baxter, Rebecca; Edvardsson, David
2018-06-01
Postgraduate education is said to support the development of nurses' professional competence and confidence, essential to the delivery of safe and effective care. However, there is a shortness of empirical evidence to demonstrate an increase to nurses' self-reported confidence and competence on completion of critical care postgraduate certificate-level education. To explore the impact of a critical care postgraduate certificate course on nurses' self-reported competence and confidence. To explore the psychometric properties and performance of the Critical Care Competence and Confidence Questionnaire. A quasi-experimental pre/post-test design. A total population sample of nurses completing a critical care postgraduate certificate course at an Australian University. The Critical Care Competence and Confidence Questionnaire was developed for this study to measure nurses' self-reported competence and confidence at baseline and follow up. Descriptive and inferential statistics were used to explore sample characteristics and changes between baseline and follow-up. Reliability of the questionnaire was explored using Cronbach's Alpha and item-total correlations. There was a statistically significant increase in competence and confidence between baseline and follow-up across all questionnaire domains. Satisfactory reliability estimates were found for the questionnaire. Completion of a critical care postgraduate certificate course significantly increased nurses' perceived competence and confidence. The Critical Care Competence and Confidence Questionnaire was found to be psychometrically sound for measuring nurses' self-reported competence and confidence. Copyright © 2018 Elsevier Ltd. All rights reserved.
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'Change4Life Smart Swaps': quasi-experimental evaluation of a natural experiment.
Wrieden, Wendy L; Levy, Louis B
2016-09-01
To evaluate the impact on food purchasing behaviour of the 'Change4Life Smart Swaps' campaign to encourage families to make small changes to lower-fat or lower-sugar versions of commonly eaten foods and drinks. Quasi-experimental study comparing the proportion of swaps made by an intervention group (267 families who had signed up to the 'Smart Swaps' campaign promoted through various media, including television and radio advertising in early 2014) and a comparison group (135 families resident in Wales, signed up for 'Change4Life' materials, but not directly exposed to the 'Smart Swaps' campaign). During weeks 1, 2 and 3 of the campaign participants were asked to record their purchases of dairy products, carbonated drinks and breakfast cereals, using a mobile phone app questionnaire, when making a purchase within the category. England and Wales. Families registered with 'Change4Life'. In weeks 2 and 3 a significantly higher percentage of the intervention group had made 'smart swaps' than the comparison group. After week 3, 58 % of participants had swapped to a lower-fat dairy product compared with 26 % of the comparison group (P<0·001), 32 % of the intervention group had purchased a lower-sugar drink compared with 19 % of the comparison group (P=0·01), and 24 % had made a change to a lower-sugar cereal compared with 12 % of the comparison group (P=0·009). In the short term a national campaign to change purchase habits towards healthier products may have some merit but the sustainability of change requires further investigation.
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Efficacy of empathy training in nursing students: A quasi-experimental study.
Bas-Sarmiento, Pilar; Fernández-Gutiérrez, Martina; Baena-Baños, María; Romero-Sánchez, Jose Manuel
2017-12-01
Empathy is a competency to be learned by nurses and a therapeutic tool in the helping relationship that has repercussions on the health of both patients and professionals. To determine the efficacy of an experiential training for improving the empathy of nursing students in terms of capacity building, empathic performance and increased learning perception and retention of the material. A quasi-experimental study of a single group with pretest-posttest measurements of the educational intervention and follow-up at one month after the training. Faculty of Nursing, University of Cádiz, Spain. Forty-eight second-year undergraduate university nursing students. The educational intervention was conducted during a single semester, with 20h of training. The methodology of role-playing, behavior assay, and a flipped classroom was followed. Measurements of student performance were collected before and after the intervention. The Reynolds Empathy Scale was used to evaluate the student's perception of his/her performance; The Consultation and Relational Empathy Measure was used to evaluate the patient's perception of the student's behavior during the simulation; and three independent external observers assessed the student's behavior, guided by The Carkhuff Scale. Descriptive analysis and non-parametric contrast tests were performed to compare the scores before and after the training (Mann-Whitney U and Wilcoxon rank-sum). Spearman's correlation coefficient was used for the correlation between the measurements. The mean scores improved for all of the variables, with the differences being statistically significant. The students assessed their learning positively. The training was shown to be effective for improving the empathy of the university students in the study. The results are promising in terms of the students retaining the competencies adquired. Therefore, this type of experiential training is recommended for empathy training of future health professionals. Copyright
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Supercontinuum generation in quadratic nonlinear waveguides without quasi-phase matching.
Guo, Hairun; Zhou, Binbin; Steinert, Michael; Setzpfandt, Frank; Pertsch, Thomas; Chung, Hung-ping; Chen, Yen-Hung; Bache, Morten
2015-02-15
Supercontinuum generation (SCG) is most efficient when the solitons can be excited directly at the pump laser wavelength. Quadratic nonlinear waveguides may induce an effective negative Kerr nonlinearity, so temporal solitons can be directly generated in the normal (positive) dispersion regime overlapping with common ultrafast laser wavelengths. There is no need for waveguide dispersion engineering. Here, we experimentally demonstrate SCG in standard lithium niobate (LN) waveguides without quasi-phase matching (QPM), pumped with femtosecond pulses in the normal dispersion regime. The observed large bandwidths (even octave spanning), together with other experimental data, indicate that negative nonlinearity solitons are indeed excited, which is backed up by numerical simulations. The QPM-free design reduces production complexity, extends the maximum waveguide length, and limits undesired spectral resonances. Finally, nonlinear crystals can be used where QPM is inefficient or impossible, which is important for mid-IR SCG. QPM-free waveguides in mid-IR nonlinear crystals can support negative nonlinearity solitons, as these waveguides have a normal dispersion at the emission wavelengths of mid-IR ultrafast lasers.
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Quasi-Static and Dynamic Response Characteristics of F-4 Bias-Ply and Radial-Belted Main Gear Tires
NASA Technical Reports Server (NTRS)
Davis, Pamela A.
1997-01-01
An investigation was conducted at Langley Research Center to determine the quasi-static and dynamic response characteristics of F-4 military fighter 30x11.5-14.5/26PR bias-ply and radial-belted main gear tires. Tire properties were measured by the application of vertical, lateral, and fore-and-aft loads. Mass moment-of-inertia data were also obtained. The results of the study include quasi-static load-deflection curves, free-vibration time-history plots, energy loss associated with hysteresis, stiffness and damping characteristics, footprint geometry, and inertia properties of each type of tire. The difference between bias-ply and radial-belted tire construction is given, as well as the advantages and disadvantages of each tire design. Three simple damping models representing viscous, structural, and Coulomb friction are presented and compared with the experimental data. The conclusions discussed contain a summary of test observations.
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2011-01-01
Introduction The role of ICU design and particularly single-patient rooms in decreasing bacterial transmission between ICU patients has been debated. A recent change in our ICU allowed further investigation. Methods Pre-move ICU-A and pre-move ICU-B were open-plan units. In March 2007, ICU-A moved to single-patient rooms (post-move ICU-A). ICU-B remained unchanged (post-move ICU-B). The same physicians cover both ICUs. Cultures of specified resistant organisms in surveillance or clinical cultures from consecutive patients staying >48 hours were compared for the different ICUs and periods to assess the effect of ICU design on acquisition of resistant organisms. Results Data were collected for 62, 62, 44 and 39 patients from pre-move ICU-A, post-move ICU-A, pre-move ICU-B and post-move ICU-B, respectively. Fewer post-move ICU-A patients acquired resistant organisms (3/62, 5%) compared with post-move ICU-B patients (7/39, 18%; P = 0.043, P = 0.011 using survival analysis) or pre-move ICU-A patients (14/62, 23%; P = 0.004, P = 0.012 on survival analysis). Only the admission period was significant for acquisition of resistant organisms comparing pre-move ICU-A with post-move ICU-A (hazard ratio = 5.18, 95% confidence interval = 1.03 to 16.06; P = 0.025). More antibiotic-free days were recorded in post-move ICU-A (median = 3, interquartile range = 0 to 5) versus post-move ICU-B (median = 0, interquartile range = 0 to 4; P = 0.070) or pre-move ICU-A (median = 0, interquartile range = 0 to 4; P = 0.017). Adequate hand hygiene was observed on 140/242 (58%) occasions in post-move ICU-A versus 23/66 (35%) occasions in post-move ICU-B (P < 0.001). Conclusions Improved ICU design, and particularly use of single-patient rooms, decreases acquisition of resistant bacteria and antibiotic use. This observation should be considered in future ICU design. PMID:21914222
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Levin, Phillip D; Golovanevski, Mila; Moses, Allon E; Sprung, Charles L; Benenson, Shmuel
2011-01-01
The role of ICU design and particularly single-patient rooms in decreasing bacterial transmission between ICU patients has been debated. A recent change in our ICU allowed further investigation. Pre-move ICU-A and pre-move ICU-B were open-plan units. In March 2007, ICU-A moved to single-patient rooms (post-move ICU-A). ICU-B remained unchanged (post-move ICU-B). The same physicians cover both ICUs. Cultures of specified resistant organisms in surveillance or clinical cultures from consecutive patients staying >48 hours were compared for the different ICUs and periods to assess the effect of ICU design on acquisition of resistant organisms. Data were collected for 62, 62, 44 and 39 patients from pre-move ICU-A, post-move ICU-A, pre-move ICU-B and post-move ICU-B, respectively. Fewer post-move ICU-A patients acquired resistant organisms (3/62, 5%) compared with post-move ICU-B patients (7/39, 18%; P = 0.043, P = 0.011 using survival analysis) or pre-move ICU-A patients (14/62, 23%; P = 0.004, P = 0.012 on survival analysis). Only the admission period was significant for acquisition of resistant organisms comparing pre-move ICU-A with post-move ICU-A (hazard ratio = 5.18, 95% confidence interval = 1.03 to 16.06; P = 0.025). More antibiotic-free days were recorded in post-move ICU-A (median = 3, interquartile range = 0 to 5) versus post-move ICU-B (median = 0, interquartile range = 0 to 4; P = 0.070) or pre-move ICU-A (median = 0, interquartile range = 0 to 4; P = 0.017). Adequate hand hygiene was observed on 140/242 (58%) occasions in post-move ICU-A versus 23/66 (35%) occasions in post-move ICU-B (P < 0.001). Improved ICU design, and particularly use of single-patient rooms, decreases acquisition of resistant bacteria and antibiotic use. This observation should be considered in future ICU design.
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The Implications of "Contamination" for Experimental Design in Education
ERIC Educational Resources Information Center
Rhoads, Christopher H.
2011-01-01
Experimental designs that randomly assign entire clusters of individuals (e.g., schools and classrooms) to treatments are frequently advocated as a way of guarding against contamination of the estimated average causal effect of treatment. However, in the absence of contamination, experimental designs that randomly assign intact clusters to…
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Teaching Experimental Design to Elementary School Pupils in Greece
ERIC Educational Resources Information Center
Karampelas, Konstantinos
2016-01-01
This research is a study about the possibility to promote experimental design skills to elementary school pupils. Experimental design and the experiment process are foundational elements in current approaches to Science Teaching, as they provide learners with profound understanding about knowledge construction and science inquiry. The research was…
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Web Based Learning Support for Experimental Design in Molecular Biology.
ERIC Educational Resources Information Center
Wilmsen, Tinri; Bisseling, Ton; Hartog, Rob
An important learning goal of a molecular biology curriculum is a certain proficiency level in experimental design. Currently students are confronted with experimental approaches in textbooks, in lectures and in the laboratory. However, most students do not reach a satisfactory level of competence in the design of experimental approaches. This…
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Nozzle design study for a quasi-axisymmetric scramjet-powered vehicle at Mach 7.9 flight conditions
NASA Astrophysics Data System (ADS)
Tanimizu, Katsuyoshi; Mee, David J.; Stalker, Raymond J.; Jacobs, Peter A.
2013-09-01
A nozzle shape optimization study for a quasi-axisymmetric scramjet has been performed for a Mach 7.9 operating condition with hydrogen fuel, aiming at the application of a hypersonic airbreathing vehicle. In this study, the nozzle geometry which is parameterized by a set of design variables, is optimized for the single objective of maximum net thrust using an in-house CFD solver for inviscid flowfields with a simple force prediction methodology. The combustion is modelled using a simple chemical reaction code. The effects of the nozzle design on the overall vehicle performance are discussed. For the present geometry, net thrust is achieved for the optimized vehicle design. The results of the nozzle-optimization study show that performance is limited by the nozzle area ratio that can be incorporated into the vehicle without leading to too large a base diameter of the vehicle and increasing the external drag of the vehicle. This study indicates that it is very difficult to achieve positive thrust at Mach 7.9 using the basic geometry investigated.
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Fabrication and characterization of hexagonally patterned quasi-1D ZnO nanowire arrays
2014-01-01
Quasi-one-dimensional (quasi-1D) ZnO nanowire arrays with hexagonal pattern have been successfully synthesized via the vapor transport process without any metal catalyst. By utilizing polystyrene microsphere self-assembled monolayer, sol–gel-derived ZnO thin films were used as the periodic nucleation sites for the growth of ZnO nanowires. High-quality quasi-1D ZnO nanowires were grown from nucleation sites, and the original hexagonal periodicity is well-preserved. According to the experimental results, the vapor transport solid condensation mechanism was proposed, in which the sol–gel-derived ZnO film acting as a seed layer for nucleation. This simple method provides a favorable way to form quasi-1D ZnO nanostructures applicable to diverse fields such as two-dimensional photonic crystal, nanolaser, sensor arrays, and other optoelectronic devices. PMID:24521308
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Dierschke, Nicole; Lowe, Diana; Plastino, Kristen
2016-01-01
Objectives. To assess whether a sexual health education intervention reduces pregnancy rates in high school students. Methods. We performed a secondary analysis of a 3-year quasi-experimental study performed in South Texas from 2011 to 2015 in which 1437 students without a history of pregnancy at baseline were surveyed each fall and spring. Potentially confounding risk factors considered included sexual behaviors, intentions, and demographics. The outcome measure was self-reported pregnancy status for male and female students. We performed analyses for male and female students using separate discrete time-to-event models. Results. We found no difference in pregnancy rates between intervention and comparison students within the first 3 years of high school. Female and male students in the intervention groups had pregnancy hazard ratios of, respectively, 1.62 (95% CI = 0.9, 2.61; P = .1) and 0.78 (95% CI = 0.44, 1.48; P = .4) relative to the comparison groups. Conclusions. The educational intervention had no impact on the pregnancy rate. Social media tools in pregnancy prevention programs should be adaptive to new technologies and rapidly changing adolescent preferences for these services. PMID:27689503
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Learning with Concept and Knowledge Maps: A Meta-Analysis
ERIC Educational Resources Information Center
Nesbit, John C.; Adesope, Olusola O.
2006-01-01
This meta-analysis reviews experimental and quasi-experimental studies in which students learned by constructing, modifying, or viewing node-link diagrams. Following an exhaustive search for studies meeting specified design criteria, 67 standardized mean difference effect sizes were extracted from 55 studies involving 5,818 participants. Students…