78 FR 25977 - Applications for New Awards; Investing in Innovation Fund, Scale-up Grants

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-03

... statistical controls for selection bias; (2) Quasi-experimental study (as defined in this notice) that meets... Act of 1965, as amended. Quasi-experimental design study means a study using a design that attempts to approximate an experimental design by identifying a comparison group that is similar to the treatment group in...

Estimating Intervention Effects across Different Types of Single-Subject Experimental Designs: Empirical Illustration

ERIC Educational Resources Information Center

Moeyaert, Mariola; Ugille, Maaike; Ferron, John M.; Onghena, Patrick; Heyvaert, Mieke; Beretvas, S. Natasha; Van den Noortgate, Wim

2015-01-01

The purpose of this study is to illustrate the multilevel meta-analysis of results from single-subject experimental designs of different types, including AB phase designs, multiple-baseline designs, ABAB reversal designs, and alternating treatment designs. Current methodological work on the meta-analysis of single-subject experimental designs…

77 FR 14036 - Draft Environmental Impact Statement for Experimental Removal of Barred Owls to Benefit...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-08

... and location of study areas, the type of experimental design, duration of study, and method of barred... by the number and location of study areas, the type of experimental design, duration of the study...-FF01E00000] Draft Environmental Impact Statement for Experimental Removal of Barred Owls to Benefit...

Magic Mirror, on the Wall-Which Is the Right Study Design of Them All?-Part I.

PubMed

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.

How scientific experiments are designed: Problem solving in a knowledge-rich, error-rich environment

NASA Astrophysics Data System (ADS)

Baker, Lisa M.

While theory formation and the relation between theory and data has been investigated in many studies of scientific reasoning, researchers have focused less attention on reasoning about experimental design, even though the experimental design process makes up a large part of real-world scientists' reasoning. The goal of this thesis was to provide a cognitive account of the scientific experimental design process by analyzing experimental design as problem-solving behavior (Newell & Simon, 1972). Three specific issues were addressed: the effect of potential error on experimental design strategies, the role of prior knowledge in experimental design, and the effect of characteristics of the space of alternate hypotheses on alternate hypothesis testing. A two-pronged in vivo/in vitro research methodology was employed, in which transcripts of real-world scientific laboratory meetings were analyzed as well as undergraduate science and non-science majors' design of biology experiments in the psychology laboratory. It was found that scientists use a specific strategy to deal with the possibility of error in experimental findings: they include "known" control conditions in their experimental designs both to determine whether error is occurring and to identify sources of error. The known controls strategy had not been reported in earlier studies with science-like tasks, in which participants' responses to error had consisted of replicating experiments and discounting results. With respect to prior knowledge: scientists and undergraduate students drew on several types of knowledge when designing experiments, including theoretical knowledge, domain-specific knowledge of experimental techniques, and domain-general knowledge of experimental design strategies. Finally, undergraduate science students generated and tested alternates to their favored hypotheses when the space of alternate hypotheses was constrained and searchable. This result may help explain findings of confirmation bias in earlier studies using science-like tasks, in which characteristics of the alternate hypothesis space may have made it unfeasible for participants to generate and test alternate hypotheses. In general, scientists and science undergraduates were found to engage in a systematic experimental design process that responded to salient features of the problem environment, including the constant potential for experimental error, availability of alternate hypotheses, and access to both theoretical knowledge and knowledge of experimental techniques.

Using Multiple Dialog Modes in a User-System Interface to Accomodate Different Levels of User Experience: An Experimental Study.

DTIC Science & Technology

1986-01-01

Chapter it Research Methodology This chapter describes the methodology and the experimental design used for this research. Prior to discussing the...50 Experimental Design ............................... 50 Task/Treatm ent ................................... 55 Task Design ...Figure 3.3 Interface Experiment Elements ............... 54 Figure 3.4 Experimental Design ....................... 55 Figure 3.5 Subject Assignment

The Use and Interpretation of Quasi-Experimental Studies in Medical Informatics

PubMed Central

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

75 FR 43172 - Maternal, Infant, and Early Childhood Home Visiting Program

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-23

... the evaluation results have been published in a peer-reviewed journal; or (bb) quasi-experimental... design (i.e. randomized controlled trial [RCT] or quasi-experimental design [QED]), level of attrition... a quasi-experimental design as a study design in which sample members are selected for the program...

Ventilation Surge Techniques. Volume I

DTIC Science & Technology

1981-12-01

studying wind-driven ventilation. S-I - . .--. .-.. .F 77I I11. EXPERIMENTAL DESIGN The full-scale model used in the experimental portion of the study was... designed to represent a typical host-area shelter. It had plan dimensions of 32 feet by 48 feet. Three floor plans were used within the same exterior...11-12 III. EXPERIMENTAL DESIGN . . . . . . . . . . . . . . . . . . . III-1 A. Literature Review . . . . . . . . . . . . . . . . . III

76 FR 38663 - Agency Information Collection Activities; Proposed Collection; Comment Request; Experimental...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-01

... on the Experimental Study of Comparative Direct-to-Consumer (DTC) Advertising. This study is designed... indirect comparisons, using comparative visuals, and using vaguer language. This study is designed to apply... Effectiveness) studies designed to explore comparative effectiveness. When this large project is completed, FDA...

Analyzing Data from a Pretest-Posttest Control Group Design: The Importance of Statistical Assumptions

ERIC Educational Resources Information Center

Zientek, Linda; Nimon, Kim; Hammack-Brown, Bryn

2016-01-01

Purpose: Among the gold standards in human resource development (HRD) research are studies that test theoretically developed hypotheses and use experimental designs. A somewhat typical experimental design would involve collecting pretest and posttest data on individuals assigned to a control or experimental group. Data from such a design that…

Considering RNAi experimental design in parasitic helminths.

PubMed

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.

Constructing experimental designs for discrete-choice experiments: report of the ISPOR Conjoint Analysis Experimental Design Good Research Practices Task Force.

PubMed

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 report by submitting written comments during the review process and oral comments during two forum presentations at the ISPOR 16th and 17th Annual International Meetings held in Baltimore (2011) and Washington, DC (2012). Copyright © 2013 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

PopED lite: An optimal design software for preclinical pharmacokinetic and pharmacodynamic studies.

PubMed

Aoki, Yasunori; Sundqvist, Monika; Hooker, Andrew C; Gennemark, Peter

2016-04-01

Optimal experimental design approaches are seldom used in preclinical drug discovery. The objective is to develop an optimal design software tool specifically designed for preclinical applications in order to increase the efficiency of drug discovery in vivo studies. Several realistic experimental design case studies were collected and many preclinical experimental teams were consulted to determine the design goal of the software tool. The tool obtains an optimized experimental design by solving a constrained optimization problem, where each experimental design is evaluated using some function of the Fisher Information Matrix. The software was implemented in C++ using the Qt framework to assure a responsive user-software interaction through a rich graphical user interface, and at the same time, achieving the desired computational speed. In addition, a discrete global optimization algorithm was developed and implemented. The software design goals were simplicity, speed and intuition. Based on these design goals, we have developed the publicly available software PopED lite (http://www.bluetree.me/PopED_lite). Optimization computation was on average, over 14 test problems, 30 times faster in PopED lite compared to an already existing optimal design software tool. PopED lite is now used in real drug discovery projects and a few of these case studies are presented in this paper. PopED lite is designed to be simple, fast and intuitive. Simple, to give many users access to basic optimal design calculations. Fast, to fit a short design-execution cycle and allow interactive experimental design (test one design, discuss proposed design, test another design, etc). Intuitive, so that the input to and output from the software tool can easily be understood by users without knowledge of the theory of optimal design. In this way, PopED lite is highly useful in practice and complements existing tools. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Experimental Learning Enhancing Improvisation Skills

ERIC Educational Resources Information Center

Pereira Christopoulos, Tania; Wilner, Adriana; Trindade Bestetti, Maria Luisa

2016-01-01

Purpose: This study aims to present improvisation training and experimentation as an alternative method to deal with unexpected events in which structured processes do not seem to work. Design/Methodology/Approach: Based on the literature of sensemaking and improvisation, the study designs a framework and process model of experimental learning…

77 FR 18251 - Development of Animal Models of Pregnancy To Address Medical Countermeasures for Influenza in the...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-27

... during pregnancy. Specifically, this workshop will address experimental design issues in selecting the... countermeasures, including influenza therapies, that may be used during pregnancy; and (3) experimental design... pharmacokinetic studies, and (3) additional issues in experimental design. Background information on the public...

Revealing Student Thinking about Experimental Design and the Roles of Control Experiments

ERIC Educational Resources Information Center

Shi, Jia; Power, Joy M.; Klymkowsky, Michael W.

2011-01-01

Well-designed "controls" distinguish experimental from non-experimental studies. Surprisingly, we found that a high percentage of students had difficulty identifying control experiments even after completing three university-level laboratory courses. To address this issue, we designed and ran a revised cell biology lab course in which…

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…

Research designs and making causal inferences from health care studies.

PubMed

Flannelly, Kevin J; Jankowski, Katherine R B

2014-01-01

This article summarizes the major types of research designs used in healthcare research, including experimental, quasi-experimental, and observational studies. Observational studies are divided into survey studies (descriptive and correlational studies), case-studies and analytic studies, the last of which are commonly used in epidemiology: case-control, retrospective cohort, and prospective cohort studies. Similarities and differences among the research designs are described and the relative strength of evidence they provide is discussed. Emphasis is placed on five criteria for drawing causal inferences that are derived from the writings of the philosopher John Stuart Mill, especially his methods or canons. The application of the criteria to experimentation is explained. Particular attention is given to the degree to which different designs meet the five criteria for making causal inferences. Examples of specific studies that have used various designs in chaplaincy research are provided.

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 performed to select experimental designs on the fly of an experiment based on their usefulness so that fewest designs are needed to reach useful inferential conclusions. Technically, function estimation is realized by Bayesian P-splines, variable selection is realized by Bayesian spike-and-slab prior, reverse prediction is realized by grid-search and design optimization is realized by the concepts of active learning. The present study demonstrated that RAAS achieves statistical robustness by making accurate predictions without the assumption of a parametric model serving as the proxy of latent data structure while the existing procedures can draw poor statistical inferences if a misspecified model is assumed; RAAS also achieves inferential efficiency by taking fewer designs to acquire useful statistical inferences than non-optimal procedures. Thus, RAAS is expected to be a principled solution to real-world experimental scenarios pursuing robust prediction and efficient experimentation.

Laboratory Experimental Design for a Glycomic Study.

PubMed

Ugrina, Ivo; Campbell, Harry; Vučković, Frano

2017-01-01

Proper attention to study design before, careful conduct of procedures during, and appropriate inference from results after scientific experiments are important in all scientific studies in order to ensure valid and sometimes definitive conclusions can be made. The design of experiments, also called experimental design, addresses the challenge of structuring and conducting experiments to answer the questions of interest as clearly and efficiently as possible.

Research designs for studies evaluating the effectiveness of change and improvement strategies.

PubMed

Eccles, M; Grimshaw, J; Campbell, M; Ramsay, C

2003-02-01

The methods of evaluating change and improvement strategies are not well described. The design and conduct of a range of experimental and non-experimental quantitative designs are considered. Such study designs should usually be used in a context where they build on appropriate theoretical, qualitative and modelling work, particularly in the development of appropriate interventions. A range of experimental designs are discussed including single and multiple arm randomised controlled trials and the use of more complex factorial and block designs. The impact of randomisation at both group and individual levels and three non-experimental designs (uncontrolled before and after, controlled before and after, and time series analysis) are also considered. The design chosen will reflect both the needs (and resources) in any particular circumstances and also the purpose of the evaluation. The general principle underlying the choice of evaluative design is, however, simple-those conducting such evaluations should use the most robust design possible to minimise bias and maximise generalisability.

Proceedings of the Symposium on Psychology in the Department of Defense (8th) Held in Colorado Springs, Colorado on 21-23 April 1982

DTIC Science & Technology

1982-12-01

readily visible but still represent low level flight. 33 Experimental Design and Pc,cedures. The experimental design used in this study was a 3 X 2...October 1979. Winer, B.J. Statistical principles in experimental design . New York: McGraw-Hill, 1971. 47 NONTRADITIONAL ADMISSIONS FACTORS: THE SPECIAL...Quasi- Experimental Designs for Research. Chicago: Rand McNally, 1963. R.C. Carter and H. Sbisa. Human Performance tests for repeated measurements

Combining Anderson's Model in the Teaching of Art Appreciation for Undergraduate Students

ERIC Educational Resources Information Center

Subramaniam, Maithreyi; Basaree, Ruzaika Omar; Hanafi, Jaffri; Putih, Abu Talib

2016-01-01

This study utilized 33 students taking creative communication design 3 in the third year of the graphic design and multimedia program, using an Anderson's model in teaching art appreciation. The quantitative research design and procedures were employed in this study. An experimental research using the quasi-experimental design, a single-group…

Conducting Research in Technical Communication: The Application of True Experimental Designs.

ERIC Educational Resources Information Center

Spyridakis, Jan H.

1992-01-01

Explains the use of true experimental designs in technical communication research, lists the eight steps in the research process, and concludes with the hope that practitioners should now be able to read research studies critically and perhaps design empirical studies of their own after further reading. (SR)

Study/experimental/research design: much more than statistics.

PubMed

Knight, Kenneth L

2010-01-01

The purpose of study, experimental, or research design in scientific manuscripts has changed significantly over the years. It has evolved from an explanation of the design of the experiment (ie, data gathering or acquisition) to an explanation of the statistical analysis. This practice makes "Methods" sections hard to read and understand. To clarify the difference between study design and statistical analysis, to show the advantages of a properly written study design on article comprehension, and to encourage authors to correctly describe study designs. The role of study design is explored from the introduction of the concept by Fisher through modern-day scientists and the AMA Manual of Style. At one time, when experiments were simpler, the study design and statistical design were identical or very similar. With the complex research that is common today, which often includes manipulating variables to create new variables and the multiple (and different) analyses of a single data set, data collection is very different than statistical design. Thus, both a study design and a statistical design are necessary. Scientific manuscripts will be much easier to read and comprehend. A proper experimental design serves as a road map to the study methods, helping readers to understand more clearly how the data were obtained and, therefore, assisting them in properly analyzing the results.

Publishing Single-Case Research Design Studies That Do Not Demonstrate Experimental Control

ERIC Educational Resources Information Center

Tincani, Matt; Travers, Jason

2018-01-01

Demonstration of experimental control is considered a hallmark of high-quality single-case research design (SCRD). Studies that fail to demonstrate experimental control may not be published because researchers are unwilling to submit these papers for publication and journals are unlikely to publish negative results (i.e., the file drawer effect).…

Experimental Methodology in English Teaching and Learning: Method Features, Validity Issues, and Embedded Experimental Design

ERIC Educational Resources Information Center

Lee, Jang Ho

2012-01-01

Experimental methods have played a significant role in the growth of English teaching and learning studies. The paper presented here outlines basic features of experimental design, including the manipulation of independent variables, the role and practicality of randomised controlled trials (RCTs) in educational research, and alternative methods…

78 FR 57171 - Experimental Removal of Barred Owls To Benefit Threatened Northern Spotted Owls; Record of...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-17

... action alternatives vary by the number and location of study areas, the type of experimental design... nonlethal), and the type of experimental design (demography vs. occupancy). All action alternatives are...-FF01E00000] Experimental Removal of Barred Owls To Benefit Threatened Northern Spotted Owls; Record of...

78 FR 44588 - Experimental Removal of Barred Owls To Benefit Threatened Northern Spotted Owls; Final...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-24

... experimental design, duration of the study, and the method of barred owl removal. Background The Service listed... and nonlethal), and the type of experimental design (demography vs. occupancy). All action...-FF01E00000] Experimental Removal of Barred Owls To Benefit Threatened Northern Spotted Owls; Final...

Reliability-based structural optimization: A proposed analytical-experimental study

NASA Technical Reports Server (NTRS)

Stroud, W. Jefferson; Nikolaidis, Efstratios

1993-01-01

An analytical and experimental study for assessing the potential of reliability-based structural optimization is proposed and described. In the study, competing designs obtained by deterministic and reliability-based optimization are compared. The experimental portion of the study is practical because the structure selected is a modular, actively and passively controlled truss that consists of many identical members, and because the competing designs are compared in terms of their dynamic performance and are not destroyed if failure occurs. The analytical portion of this study is illustrated on a 10-bar truss example. In the illustrative example, it is shown that reliability-based optimization can yield a design that is superior to an alternative design obtained by deterministic optimization. These analytical results provide motivation for the proposed study, which is underway.

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…

Using experimental design to define boundary manikins.

PubMed

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.

Single subject controlled experiments in aphasia: The science and the state of the science

PubMed Central

Thompson, Cynthia K.

2007-01-01

This paper discusses the use of single subject controlled experimental designs for investigating the effect of treatment for aphasia. A brief historical perspective is presented, followed by discussions of the advantages and disadvantages of single subject and group approaches, the basic requirements of single subject experimental research, and crucial considerations in design selection. In the final sections, results of reviews of published single subject controlled experiments are discussed, with emphasis on internal validity issues, the number of participants enrolled in published studies, operational specification of the dependent and independent variables, and reliability of measurement. Learning outcomes As a result of reading this paper, the participant will: (1) understand the mechanisms required for demonstration of internal and external validity using single subject controlled experimental designs, (2) become familiar with the basic requirements of single subject controlled experimental research, (3) understand the types of single subject controlled experimental designs that are the most appropriate for studying the effects of treatment for aphasia, and (4) become familiar with trends in the published aphasia treatment literature in which single subject controlled experimental designs have been used. PMID:16635494

Study/Experimental/Research Design: Much More Than Statistics

PubMed Central

Knight, Kenneth L.

2010-01-01

Abstract Context: The purpose of study, experimental, or research design in scientific manuscripts has changed significantly over the years. It has evolved from an explanation of the design of the experiment (ie, data gathering or acquisition) to an explanation of the statistical analysis. This practice makes “Methods” sections hard to read and understand. Objective: To clarify the difference between study design and statistical analysis, to show the advantages of a properly written study design on article comprehension, and to encourage authors to correctly describe study designs. Description: The role of study design is explored from the introduction of the concept by Fisher through modern-day scientists and the AMA Manual of Style. At one time, when experiments were simpler, the study design and statistical design were identical or very similar. With the complex research that is common today, which often includes manipulating variables to create new variables and the multiple (and different) analyses of a single data set, data collection is very different than statistical design. Thus, both a study design and a statistical design are necessary. Advantages: Scientific manuscripts will be much easier to read and comprehend. A proper experimental design serves as a road map to the study methods, helping readers to understand more clearly how the data were obtained and, therefore, assisting them in properly analyzing the results. PMID:20064054

76 FR 28788 - Proposed Data Collections Submitted for Public Comment and Recommendations

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-18

... studies have been quasi-experimental designs focused on short term workload assessments as outcomes. The... experimental research to define further the effectiveness and cost-benefit of MSD control interventions. A... prospective experimental design (multiple baselines across groups with randomization). These interventions...

Predictive and postdictive analysis of forage yield trials

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...

75 FR 12003 - Investing in Innovation Fund

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-12

..., Proposed Practice, Strategy, or implemented experimental implemented strategy, or program, Program. study or well-designed experimental or quasi- or one similar to it, and well-implemented experimental study, has been attempted quasi-experimental with small sample sizes previously, albeit on a study; or (2...

Toxic Hazards Research Unit 1989

DTIC Science & Technology

1990-10-01

frequently be developed to drive the experimental design and to assist in risk avsessments. The Toxic Hazards Division, Harry G. Armstrong Aerospace...postexposure, respectively. The experimental design (Section 3.3, Subchronic Inhalation Toxicity Studies on 3.1 Oil at Concentrations of 250, 50, and...sodium salt and the pH was adjusted to 7.4. 101 EXPERIMENTAL DESIGN Initiation Assessment A total of seven groups consisting of eight animals per

Inclusion of quasi-experimental studies in systematic reviews of health systems research.

PubMed

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.

The influence of the design matrix on treatment effect estimates in the quantitative analyses of single-subject experimental design research.

PubMed

Moeyaert, Mariola; Ugille, Maaike; Ferron, John M; Beretvas, S Natasha; Van den Noortgate, Wim

2014-09-01

The quantitative methods for analyzing single-subject experimental data have expanded during the last decade, including the use of regression models to statistically analyze the data, but still a lot of questions remain. One question is how to specify predictors in a regression model to account for the specifics of the design and estimate the effect size of interest. These quantitative effect sizes are used in retrospective analyses and allow synthesis of single-subject experimental study results which is informative for evidence-based decision making, research and theory building, and policy discussions. We discuss different design matrices that can be used for the most common single-subject experimental designs (SSEDs), namely, the multiple-baseline designs, reversal designs, and alternating treatment designs, and provide empirical illustrations. The purpose of this article is to guide single-subject experimental data analysts interested in analyzing and meta-analyzing SSED data. © The Author(s) 2014.

1983 AFOSR/AFRPL Chemical Rocket Research Meeting, Abstracts and Agenda. Includes: Abstracts on Advanced Diagnostics of Reacting Flow, 28 February - 3 March 1983, Lancaster, California.

DTIC Science & Technology

1983-02-01

blow-off stability and fractional conversion was evaluated for design of an experimental study of these phenomena. The apparatus designed will be...the development of an array of experimental methods and test strategies designed to unravel a complex process that is very difficult to observe directly...this effort of lead field theoretic analysis as a design basis has made that possible. The experimental phase of the effort has three major

Experimental Design: Utilizing Microsoft Mathematics in Teaching and Learning Calculus

ERIC Educational Resources Information Center

Oktaviyanthi, Rina; Supriani, Yani

2015-01-01

The experimental design was conducted to investigate the use of Microsoft Mathematics, free software made by Microsoft Corporation, in teaching and learning Calculus. This paper reports results from experimental study details on implementation of Microsoft Mathematics in Calculus, students' achievement and the effects of the use of Microsoft…

EXPERIMENTAL STUDIES ON PARTICLE IMPACTION AND BOUNCE: EFFECTS OF SUBSTRATE DESIGN AND MATERIAL. (R825270)

EPA Science Inventory

This paper presents an experimental investigation of the effects of impaction substrate designs and material in reducing particle bounce and reentrainment. Particle collection without coating by using combinations of different impaction substrate designs and surface materials was...

Design approaches to experimental mediation☆

PubMed Central

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

Design approaches to experimental mediation.

PubMed

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.

Trade-offs in experimental designs for estimating post-release mortality in containment studies

USGS Publications Warehouse

Rogers, Mark W.; Barbour, Andrew B; Wilson, Kyle L

2014-01-01

Estimates of post-release mortality (PRM) facilitate accounting for unintended deaths from fishery activities and contribute to development of fishery regulations and harvest quotas. The most popular method for estimating PRM employs containers for comparing control and treatment fish, yet guidance for experimental design of PRM studies with containers is lacking. We used simulations to evaluate trade-offs in the number of containers (replicates) employed versus the number of fish-per container when estimating tagging mortality. We also investigated effects of control fish survival and how among container variation in survival affects the ability to detect additive mortality. Simulations revealed that high experimental effort was required when: (1) additive treatment mortality was small, (2) control fish mortality was non-negligible, and (3) among container variability in control fish mortality exceeded 10% of the mean. We provided programming code to allow investigators to compare alternative designs for their individual scenarios and expose trade-offs among experimental design options. Results from our simulations and simulation code will help investigators develop efficient PRM experimental designs for precise mortality assessment.

Quasi-experimental study designs series-paper 7: assessing the assumptions.

PubMed

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.

Design and Experimental Study on Spinning Solid Rocket Motor

NASA Astrophysics Data System (ADS)

Xue, Heng; Jiang, Chunlan; Wang, Zaicheng

The study on spinning solid rocket motor (SRM) which used as power plant of twice throwing structure of aerial submunition was introduced. This kind of SRM which with the structure of tangential multi-nozzle consists of a combustion chamber, propellant charge, 4 tangential nozzles, ignition device, etc. Grain design, structure design and prediction of interior ballistic performance were described, and problem which need mainly considered in design were analyzed comprehensively. Finally, in order to research working performance of the SRM, measure pressure-time curve and its speed, static test and dynamic test were conducted respectively. And then calculated values and experimental data were compared and analyzed. The results indicate that the designed motor operates normally, and the stable performance of interior ballistic meet demands. And experimental results have the guidance meaning for the pre-research design of SRM.

Increasing efficiency of preclinical research by group sequential designs

PubMed Central

Piper, Sophie K.; Rex, Andre; Florez-Vargas, Oscar; Karystianis, George; Schneider, Alice; Wellwood, Ian; Siegerink, Bob; Ioannidis, John P. A.; Kimmelman, Jonathan; Dirnagl, Ulrich

2017-01-01

Despite the potential benefits of sequential designs, studies evaluating treatments or experimental manipulations in preclinical experimental biomedicine almost exclusively use classical block designs. Our aim with this article is to bring the existing methodology of group sequential designs to the attention of researchers in the preclinical field and to clearly illustrate its potential utility. Group sequential designs can offer higher efficiency than traditional methods and are increasingly used in clinical trials. Using simulation of data, we demonstrate that group sequential designs have the potential to improve the efficiency of experimental studies, even when sample sizes are very small, as is currently prevalent in preclinical experimental biomedicine. When simulating data with a large effect size of d = 1 and a sample size of n = 18 per group, sequential frequentist analysis consumes in the long run only around 80% of the planned number of experimental units. In larger trials (n = 36 per group), additional stopping rules for futility lead to the saving of resources of up to 30% compared to block designs. We argue that these savings should be invested to increase sample sizes and hence power, since the currently underpowered experiments in preclinical biomedicine are a major threat to the value and predictiveness in this research domain. PMID:28282371

76 FR 78927 - Proposed Information Collection Activity; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-20

... estimates of the effectiveness of the programs. This component will use an experimental design. Program... inform decisions related to future investments in this kind of programming as well as the design and operation of such services. To meet the objective of the study, experimental impact studies with...

SELF-INSTRUCTIONAL SUPPLEMENTS FOR A TELEVISED PHYSICS COURSE, STUDY PLAN AND EXPERIMENTAL DESIGN.

ERIC Educational Resources Information Center

KLAUS, DAVID J.; LUMSDAINE, ARTHUR A.

THE INITIAL PHASES OF A STUDY OF SELF-INSTRUCTIONAL AIDS FOR A TELEVISED PHYSICS COURSE WERE DESCRIBED. THE APPROACH, EXPERIMENTAL DESIGN, PROCEDURE, AND TECHNICAL ASPECTS OF THE STUDY PLAN WERE INCLUDED. THE MATERIALS WERE PREPARED TO SUPPLEMENT THE SECOND SEMESTER OF HIGH SCHOOL PHYSICS. THE MATERIAL COVERED STATIC AND CURRENT ELECTRICITY,…

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

Labby, Z.

Physicists are often expected to have a solid grounding in experimental design and statistical analysis, sometimes filling in when biostatisticians or other experts are not available for consultation. Unfortunately, graduate education on these topics is seldom emphasized and few opportunities for continuing education exist. Clinical physicists incorporate new technology and methods into their practice based on published literature. A poor understanding of experimental design and analysis could Result in inappropriate use of new techniques. Clinical physicists also improve current practice through quality initiatives that require sound experimental design and analysis. Academic physicists with a poor understanding of design and analysismore » may produce ambiguous (or misleading) results. This can Result in unnecessary rewrites, publication rejection, and experimental redesign (wasting time, money, and effort). This symposium will provide a practical review of error and uncertainty, common study designs, and statistical tests. Instruction will primarily focus on practical implementation through examples and answer questions such as: where would you typically apply the test/design and where is the test/design typically misapplied (i.e., common pitfalls)? An analysis of error and uncertainty will also be explored using biological studies and associated modeling as a specific use case. Learning Objectives: Understand common experimental testing and clinical trial designs, what questions they can answer, and how to interpret the results Determine where specific statistical tests are appropriate and identify common pitfalls Understand the how uncertainty and error are addressed in biological testing and associated biological modeling.« less

Human Factors Engineering Bibliographic Series. Volume 5, 1967 Literature

DTIC Science & Technology

1976-03-01

8217aining progracus designed to In- crease arn strength. There were 26 subects In each group. those In the experimental group, static and dyl’sic... experimental design over more usual classical procedures are Swq* gested.a’ 32,258 Cohen. 1t.l. CONTINUOUS VERSUS Tti. VISUAL FEEDSAX INl PRISM... experimental study was :?arformeed to evaluate, singly &no In combination, the effective- ness of a is-hr. training progrm and a set of visual aids designed to

Assessing the Effectiveness of a Computer Simulation for Teaching Ecological Experimental Design

ERIC Educational Resources Information Center

Stafford, Richard; Goodenough, Anne E.; Davies, Mark S.

2010-01-01

Designing manipulative ecological experiments is a complex and time-consuming process that is problematic to teach in traditional undergraduate classes. This study investigates the effectiveness of using a computer simulation--the Virtual Rocky Shore (VRS)--to facilitate rapid, student-centred learning of experimental design. We gave a series of…

Sensory imbalance as mechanism of orientation disruption in the leafminer, Phyllocnistis citrella: Elucidation by multivariate geometric designs and response surface models

USDA-ARS?s Scientific Manuscript database

Experimental designs developed to address mixtures are ideally suited for many areas of experimental biology including pheromone blend studies because they address the confounding of proportionality and concentration intrinsic to factorial and one-factor-at-a-time designs. Geometric multivariate des...

Return to Our Roots: Raising Radishes to Teach Experimental Design. Methods and Techniques.

ERIC Educational Resources Information Center

Stallings, William M.

1993-01-01

Reviews research in teaching applied statistics. Concludes that students should analyze data from studies they have designed and conducted. Describes an activity in which students study germination and growth of radish seeds. Includes a table providing student instructions for both the experimental procedure and data analysis. (CFR)

Using experimental design and spatial analyses to improve the precision of NDVI estimates in upland cotton field trials

USDA-ARS?s Scientific Manuscript database

Controlling for spatial variability is important in high-throughput phenotyping studies that enable large numbers of genotypes to be evaluated across time and space. In the current study, we compared the efficacy of different experimental designs and spatial models in the analysis of canopy spectral...

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

ERIC Educational Resources Information Center

Asteris, Mark M., Jr.

2012-01-01

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

Effect of experimental design on production responses in high-producing dairy cows fed two levels of metabolizable protein

USDA-ARS?s Scientific Manuscript database

Results from studies on lactation responses to diet have been hypothesized to be affected by the use of change-over (CHANGE) instead of continuous (CONT) experimental designs; a direct test of this hypothesis has not been well-studied. The objective of this study was to evaluate the effects of reduc...

Optimizing methods and dodging pitfalls in microbiome research.

PubMed

Kim, Dorothy; Hofstaedter, Casey E; Zhao, Chunyu; Mattei, Lisa; Tanes, Ceylan; Clarke, Erik; Lauder, Abigail; Sherrill-Mix, Scott; Chehoud, Christel; Kelsen, Judith; Conrad, Máire; Collman, Ronald G; Baldassano, Robert; Bushman, Frederic D; Bittinger, Kyle

2017-05-05

Research on the human microbiome has yielded numerous insights into health and disease, but also has resulted in a wealth of experimental artifacts. Here, we present suggestions for optimizing experimental design and avoiding known pitfalls, organized in the typical order in which studies are carried out. We first review best practices in experimental design and introduce common confounders such as age, diet, antibiotic use, pet ownership, longitudinal instability, and microbial sharing during cohousing in animal studies. Typically, samples will need to be stored, so we provide data on best practices for several sample types. We then discuss design and analysis of positive and negative controls, which should always be run with experimental samples. We introduce a convenient set of non-biological DNA sequences that can be useful as positive controls for high-volume analysis. Careful analysis of negative and positive controls is particularly important in studies of samples with low microbial biomass, where contamination can comprise most or all of a sample. Lastly, we summarize approaches to enhancing experimental robustness by careful control of multiple comparisons and to comparing discovery and validation cohorts. We hope the experimental tactics summarized here will help researchers in this exciting field advance their studies efficiently while avoiding errors.

The Missing Treatment Design Element: Continuity of Treatment When Multiple Postobservations Are Used in Time-Series and Repeated Measures Study Designs

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…

Magnetohydrodynamic generator experimental studies

NASA Technical Reports Server (NTRS)

Pierson, E. S.

1972-01-01

The results for an experimental study of a one wavelength MHD induction generator operating on a liquid flow are presented. First the design philosophy and the experimental generator design are summarized, including a description of the flow loop and instrumentation. Next a Fourier series method of treating the fact that the magnetic flux density produced by the stator is not a pure traveling sinusoid is described and some results summarized. This approach appears to be of interest after revisions are made, but the initial results are not accurate. Finally, some of the experimental data is summarized for various methods of excitation.

Assessing Pupils' Skills in Experimentation

ERIC Educational Resources Information Center

Hammann, Marcus; Phan, Thi Thanh Hoi; Ehmer, Maike; Grimm, Tobias

2008-01-01

This study is concerned with different forms of assessment of pupils' skills in experimentation. The findings of three studies are reported. Study 1 investigates whether it is possible to develop reliable multiple-choice tests for the skills of forming hypotheses, designing experiments and analysing experimental data. Study 2 compares scores from…

The effects of overhead transparency design on retention, recall, and application of data analysis content.

PubMed

Van Hoozer, H; Brink, P J; Oppliger, R

1989-04-01

This experimental study tested the effects of overhead transparency design in conjunction with live lecture on retention, recall, and application of data analysis content over three occasions using a Solomon Four-Group, pretest-posttest design. Pretested subjects showed significant (p less than .001) gains in test scores from pre to posttest. No significant differences were found in pretest scores between control and experimental treatment groups or among the posttest scores of either the experimental or control groups.

Designing Studies That Would Address the Multilayered Nature of Health Care

PubMed Central

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

Experimental design and quantitative analysis of microbial community multiomics.

PubMed

Mallick, Himel; Ma, Siyuan; Franzosa, Eric A; Vatanen, Tommi; Morgan, Xochitl C; Huttenhower, Curtis

2017-11-30

Studies of the microbiome have become increasingly sophisticated, and multiple sequence-based, molecular methods as well as culture-based methods exist for population-scale microbiome profiles. To link the resulting host and microbial data types to human health, several experimental design considerations, data analysis challenges, and statistical epidemiological approaches must be addressed. Here, we survey current best practices for experimental design in microbiome molecular epidemiology, including technologies for generating, analyzing, and integrating microbiome multiomics data. We highlight studies that have identified molecular bioactives that influence human health, and we suggest steps for scaling translational microbiome research to high-throughput target discovery across large populations.

An experimental and theoretical study of structural damping in compliant foil bearings

NASA Technical Reports Server (NTRS)

Ku, C.-P. Roger

1994-01-01

This paper describes an experimental investigation into the dynamic characteristics of corrugated foil (bump foil) strips used in compliant surface foil bearings. This study provided and opportunity to quantify the structural damping of bump foil strips. The experimental data were compared to results obtained by a theoretical model developed earlier. The effects of bearing design parameters, such as static loads, dynamic displacement amplitudes, bump configurations, pivot locations, surface coatings, and lubricant were also evaluated. An understanding of the dynamic characteristics of bump foil strips resulting from this work offers designers a means for enhancing the design of high-performance compliant foil bearings.

Overview of clinical research design.

PubMed

Hartung, Daniel M; Touchette, Daniel

2009-02-15

Basic concepts and terminology of clinical research design are presented for new clinical investigators. Clinical research, research involving human subjects, can be described as either observational or experimental. The findings of all clinical research can be threatened by issues of bias and confounding. Biases are systematic errors in how study subjects are selected or measured, which result in false inferences. Confounding is a distortion in findings that is attributable to mixing variable effects. Uncontrolled observation research is generally more prone to bias and confounding than experimental research. Observational research includes designs such as the cohort study, case-control study, and cross-sectional study, while experimental research typically involves a randomized controlled trial (RCT). The cohort study, which includes the RCT, defines subject allocation on the basis of exposure interest (e.g., drug, disease-management program) and follows the patients to assess the outcomes. The case-control study uses the primary outcome of interest (e.g., adverse event) to define subject allocation, and different exposures are assessed in a retrospective manner. Cross-sectional research evaluates both exposure and outcome concurrently. Each of these design methods possesses different strengths and weaknesses in answering research questions, as well as underlying many study subtypes. While experimental research is the strongest method for establishing causality, it can be difficult to accomplish under many scenarios. Observational clinical research offers many design alternatives that may be appropriate if planned and executed carefully.

Stated Choice design comparison in a developing country: recall and attribute nonattendance

PubMed Central

2014-01-01

Background Experimental designs constitute a vital component of all Stated Choice (aka discrete choice experiment) studies. However, there exists limited empirical evaluation of the statistical benefits of Stated Choice (SC) experimental designs that employ non-zero prior estimates in constructing non-orthogonal constrained designs. This paper statistically compares the performance of contrasting SC experimental designs. In so doing, the effect of respondent literacy on patterns of Attribute non-Attendance (ANA) across fractional factorial orthogonal and efficient designs is also evaluated. The study uses a ‘real’ SC design to model consumer choice of primary health care providers in rural north India. A total of 623 respondents were sampled across four villages in Uttar Pradesh, India. Methods Comparison of orthogonal and efficient SC experimental designs is based on several measures. Appropriate comparison of each design’s respective efficiency measure is made using D-error results. Standardised Akaike Information Criteria are compared between designs and across recall periods. Comparisons control for stated and inferred ANA. Coefficient and standard error estimates are also compared. Results The added complexity of the efficient SC design, theorised elsewhere, is reflected in higher estimated amounts of ANA among illiterate respondents. However, controlling for ANA using stated and inferred methods consistently shows that the efficient design performs statistically better. Modelling SC data from the orthogonal and efficient design shows that model-fit of the efficient design outperform the orthogonal design when using a 14-day recall period. The performance of the orthogonal design, with respect to standardised AIC model-fit, is better when longer recall periods of 30-days, 6-months and 12-months are used. Conclusions The effect of the efficient design’s cognitive demand is apparent among literate and illiterate respondents, although, more pronounced among illiterate respondents. This study empirically confirms that relaxing the orthogonality constraint of SC experimental designs increases the information collected in choice tasks, subject to the accuracy of the non-zero priors in the design and the correct specification of a ‘real’ SC recall period. PMID:25386388

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…

Effects of Training in Universal Design for Learning on Lesson Plan Development

ERIC Educational Resources Information Center

Spooner, Fred; Baker, Joshua N.; Harris, Amber A.; Ahlgrim-Delzell, Lynn; Browder, Diane M.

2007-01-01

The effects of training in Universal Design for Learning (UDL) on lesson plan development of special and general educators in a college classroom environment were investigated. A true experimental group design with a control group was used for this study. A one-hour teacher training session introduced UDL to the experimental group; the control…

Design of field experiments: Influence of treatment response relative to standard deviation and blocking factor characteristics on efficient blocking strategy

USDA-ARS?s Scientific Manuscript database

Selection of experimental design can markedly influence efficiency of field research. This study used Monte Carlo simulations to compare the ability of different field experimental designs to distinguish defined treatment differences, and the paper concludes with a section on practical use of the in...

Marginal biotin deficiency can be induced experimentally in humans using a cost-effective outpatient design.

PubMed

Stratton, Shawna L; Henrich, Cindy L; Matthews, Nell I; Bogusiewicz, Anna; Dawson, Amanda M; Horvath, Thomas D; Owen, Suzanne N; Boysen, Gunnar; Moran, Jeffery H; Mock, Donald M

2012-01-01

To date, marginal, asymptomatic biotin deficiency has been successfully induced experimentally by the use of labor-intensive inpatient designs requiring rigorous dietary control. We sought to determine if marginal biotin deficiency could be induced in humans in a less expensive outpatient design incorporating a self-selected, mixed general diet. We sought to examine the efficacy of three outpatient study designs: two based on oral avidin dosing and one based on a diet high in undenatured egg white for a period of 28 d. In study design 1, participants (n = 4; 3 women) received avidin in capsules with a biotin binding capacity of 7 times the estimated dietary biotin intake of a typical self-selected diet. In study design 2, participants (n = 2; 2 women) received double the amount of avidin capsules (14 times the estimated dietary biotin intake). In study design 3, participants (n = 5; 3 women) consumed egg-white beverages containing avidin with a biotin binding capacity of 7 times the estimated dietary biotin intake. Established indices of biotin status [lymphocyte propionyl-CoA carboxylase activity; urinary excretion of 3-hydroxyisovaleric acid, 3-hydroxyisovaleryl carnitine (3HIA-carnitine), and biotin; and plasma concentration of 3HIA-carnitine] indicated that study designs 1 and 2 were not effective in inducing marginal biotin deficiency, but study design 3 was as effective as previous inpatient study designs that induced deficiency by egg-white beverage. Marginal biotin deficiency can be induced experimentally by using a cost-effective outpatient design by avidin delivery in egg-white beverages. This design should be useful to the broader nutritional research community.

Third National Even Start Evaluation: Follow-Up Findings from the Experimental Design Study. NCEE 2005-3002

ERIC Educational Resources Information Center

Ricciuti, Anne E., St.Pierre, Robert G.; Lee, Wang; Parsad, Amanda

2004-01-01

Citation: Ricciuti, A.E., R.G. St.Pierre, W. Lee, A. Parsad & T. Rimdzius. Third National Even Start Evaluation: Follow-Up Findings From the Experimental Design Study. U.S. Department of Education, Institute of Education Sciences, National Center for Education Evaluation and Regional Assistance. Washington, D.C., 2004. Background: The Even…

Bias Corrections for Standardized Effect Size Estimates Used with Single-Subject Experimental Designs

ERIC Educational Resources Information Center

Ugille, Maaike; Moeyaert, Mariola; Beretvas, S. Natasha; Ferron, John M.; Van den Noortgate, Wim

2014-01-01

A multilevel meta-analysis can combine the results of several single-subject experimental design studies. However, the estimated effects are biased if the effect sizes are standardized and the number of measurement occasions is small. In this study, the authors investigated 4 approaches to correct for this bias. First, the standardized effect…

The system design and performance test of hybrid vertical axis wind turbine

NASA Astrophysics Data System (ADS)

Dwiyantoro, Bambang Arip; Suphandani, Vivien

2017-04-01

Vertical axis wind turbine is a tool that is being developed to generate energy from wind. One cause is still little use of wind energy is the design of wind turbines that are less precise. Therefore in this study will be developed the system design of hybrid vertical axis wind turbine and tested performance with experimental methods. The design of hybrid turbine based on a straight bladed Darrieus turbine along with a double step Savonius turbine. The method used to design wind turbines is by studying literature, analyzing the critical parts of a wind turbine and the structure of the optimal design. Wind turbine prototype of the optimal design characteristic tests in the wind tunnel experimentally by varying the speed of the wind. From the experimental results show that the greater the wind speed, the greater the wind turbine rotation and torque is raised. The hybrid vertical axis wind turbine has much better self-starting and better conversion efficiency.

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

ERIC Educational Resources Information Center

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

2015-01-01

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

Structural and compositional features of high-rise buildings: experimental design in Yekaterinburg

NASA Astrophysics Data System (ADS)

Yankovskaya, Yulia; Lobanov, Yuriy; Temnov, Vladimir

2018-03-01

The study looks at the specifics of high-rise development in Yekaterinburg. High-rise buildings are considered in the context of their historical development, structural features, compositional and imaginative design techniques. Experience of Yekaterinburg architects in experimental design is considered and analyzed. Main issues and prospects of high-rise development within the Yekaterinburg structure are studied. The most interesting and significant conceptual approaches to the structural and compositional arrangement of high-rise buildings are discussed.

The Use of Interrupted Case Studies to Enhance Critical Thinking Skills in Biology

PubMed Central

White, Tracy K.; Whitaker, Paul; Gonya, Terri; Hein, Richard; Kroening, Dubear; Lee, Kevin; Lee, Laura; Lukowiak, Andrea; Hayes, Elizabeth

2009-01-01

There has been a dramatic increase in the availability of case studies for use in the biology classroom, and perceptions of the effectiveness of case-study-based learning are overwhelmingly positive. Here we report the results of a study in which we evaluated the ability of interrupted case studies to improve critical thinking in the context of experimental design and the conventions of data interpretation. Students were assessed using further case studies designed to evaluate their ability to recognize and articulate problematic approaches to these elements of experimentation. Our work reveals that case studies have broad utility in the classroom. In addition to demonstrating a small but statistically significant increase in the number of students capable of critically evaluating selected aspects of experimental design, we also observed increased student engagement and documented widespread misconceptions regarding the conventions of data acquisition and analysis. PMID:23653687

Experimental Design for Evaluating the Safety Benefits of Railroad Advance Warning Signs

DOT National Transportation Integrated Search

1979-04-01

The report presents the findings and conclusions of a study to develop an experimental design and analysis plan for field testing and evaluation of the accident reduction potential of a proposed new railroad grade crossing advance warning sign. Sever...

Exploratory studies of the cruise performance of upper surface blown configurations. Experimental program: Test facilities, model design instrumentation, and lowspeed, high-lift tests

NASA Technical Reports Server (NTRS)

Braden, J. A.; Hancock, J. P.; Burdges, K. P.; Hackett, J. E.

1980-01-01

The model hardware, test facilities and instrumentation utilized in an experimental study of upper surface blown configurations at cruise is described. The high speed (subsonic) experimental work, studying the aerodynamic effects of wing nacelle geometric variations, was conducted around semispan model configurations composed of diversified, interchangeable components. Power simulation was provided by high pressure air ducted through closed forebody nacelles. Nozzle geometry was varied across size, exit aspect ratio, exit position and boattail angle. Three dimensional force and two dimensional pressure measurements were obtained at cruise Mach numbers from 0.5 to 0.8 and at nozzle pressure ratios up to about 3.0. The experimental investigation was supported by an analytical synthesis of the system using a vortex lattice representation with first order power effects. Results are also presented from a compatibility study in which a short haul transport is designed on the basis of the aerodynamic findings in the experimental study as well as acoustical data obtained in a concurrent program. High lift test data are used to substantiate the projected performance of the selected transport design.

Design of a factorial experiment with randomization restrictions to assess medical device performance on vascular tissue.

PubMed

Diestelkamp, Wiebke S; Krane, Carissa M; Pinnell, Margaret F

2011-05-20

Energy-based surgical scalpels are designed to efficiently transect and seal blood vessels using thermal energy to promote protein denaturation and coagulation. Assessment and design improvement of ultrasonic scalpel performance relies on both in vivo and ex vivo testing. The objective of this work was to design and implement a robust, experimental test matrix with randomization restrictions and predictive statistical power, which allowed for identification of those experimental variables that may affect the quality of the seal obtained ex vivo. The design of the experiment included three factors: temperature (two levels); the type of solution used to perfuse the artery during transection (three types); and artery type (two types) resulting in a total of twelve possible treatment combinations. Burst pressures of porcine carotid and renal arteries sealed ex vivo were assigned as the response variable. The experimental test matrix was designed and carried out as a split-plot experiment in order to assess the contributions of several variables and their interactions while accounting for randomization restrictions present in the experimental setup. The statistical software package SAS was utilized and PROC MIXED was used to account for the randomization restrictions in the split-plot design. The combination of temperature, solution, and vessel type had a statistically significant impact on seal quality. The design and implementation of a split-plot experimental test-matrix provided a mechanism for addressing the existing technical randomization restrictions of ex vivo ultrasonic scalpel performance testing, while preserving the ability to examine the potential effects of independent factors or variables. This method for generating the experimental design and the statistical analyses of the resulting data are adaptable to a wide variety of experimental problems involving large-scale tissue-based studies of medical or experimental device efficacy and performance.

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 experimental design was completed by a center-point glass, a Vitreous State Laboratory glass, and replicates of the center point and Vitreous State Laboratory glasses.« less

Experimental research of radio-frequency ion thruster

NASA Astrophysics Data System (ADS)

Antropov, N. N.; Akhmetzhanov, R. V.; Bogatyy, A. V.; Grishin, R. A.; Kozhevnikov, V. V.; Plokhikh, A. P.; Popov, G. A.; Khartov, S. A.

2016-12-01

The article is devoted to the research of low-power (300 W) radio-frequency ion thruster designed at the Moscow Aviation Institute. The main results of experimental research of the thruster using the testfacility power supplies and the power processing unit of their own design are presented. The dependence of the working fluid ionization cost on its mass flow rate at the constant ion beam current was investigated experimentally. The influence of the shape and material of the discharge chamber on the integral characteristics of the thruster was studied. The recommendations on the optimization of the thruster primary performance were developed based on the results of experimental studies.

Identifying Effective Treatments from a Brief Experimental Analysis: Using a Single-Case Design Elements To Aid Decision Making.

ERIC Educational Resources Information Center

Martens, Brian K.; Eckert, Tanya L.; Bradley, Tracy A.; Ardoin, Scott P.

1999-01-01

Discusses the benefits of using brief experimental analysis to aid in treatment selection, identifies the forms of treatment that are most appropriate for this type of analysis, and describes key design elements for comparing treatments. Presents a study demonstrating the use of these design elements to identify an effective intervention for two…

Solid Aerosol Program

DTIC Science & Technology

1993-04-01

not to be construed as an official Department of the Army position unless so designated by other authorizing documents. REPORT DOCUMENTATION PAGE...parameter sensitivity studies, and test procedure design . An experimental system providing reaL data on the parametters relevant to the calculations has been...experimental program was designed to exploit as much of the existing capabilities of the Ventilation Kinetics group as possible while keeping in mind

Teaching neurophysiology, neuropharmacology, and experimental design using animal models of psychiatric and neurological disorders.

PubMed

Morsink, Maarten C; Dukers, Danny F

2009-03-01

Animal models have been widely used for studying the physiology and pharmacology of psychiatric and neurological diseases. The concepts of face, construct, and predictive validity are used as indicators to estimate the extent to which the animal model mimics the disease. Currently, we used these three concepts to design a theoretical assignment to integrate the teaching of neurophysiology, neuropharmacology, and experimental design. For this purpose, seven case studies were developed in which animal models for several psychiatric and neurological diseases were described and in which neuroactive drugs used to treat or study these diseases were introduced. Groups of undergraduate students were assigned to one of these case studies and asked to give a classroom presentation in which 1) the disease and underlying pathophysiology are described, 2) face and construct validity of the animal model are discussed, and 3) a pharmacological experiment with the associated neuroactive drug to assess predictive validity is presented. After evaluation of the presentations, we found that the students had gained considerable insight into disease phenomenology, its underlying neurophysiology, and the mechanism of action of the neuroactive drug. Moreover, the assignment was very useful in the teaching of experimental design, allowing an in-depth discussion of experimental control groups and the prediction of outcomes in these groups if the animal model were to display predictive validity. Finally, the highly positive responses in the student evaluation forms indicated that the assignment was of great interest to the students. Hence, the currently developed case studies constitute a very useful tool for teaching neurophysiology, neuropharmacology, and experimental design.

[Realization of design regarding experimental research in the clinical real-world research].

PubMed

He, Q; Shi, J P

2018-04-10

Real world study (RWS), a further verification and supplement for explanatory randomized controlled trial to evaluate the effectiveness of intervention measures in real clinical environment, has increasingly become the focus in the field of research on medical and health care services. However, some people mistakenly equate real world study with observational research, and argue that intervention and randomization cannot be carried out in real world study. In fact, both observational and experimental design are the basic designs in real world study, while the latter usually refers to pragmatic randomized controlled trial and registry-based randomized controlled trial. Other nonrandomized controlled and adaptive designs can also be adopted in the RWS.

A Comparative Study of Integrating Multimedia into the Third Grade Math Curriculum to Improve Math Learning

ERIC Educational Resources Information Center

Liu, Yuliang

2013-01-01

This quasi-experimental study was to design, develop, and implement one multimedia math lesson in third grade to improve students' math learning. The non-equivalent control group design was used. The experimental group had 11 third grade students and the control group had 15 third grade students in an African American predominated elementary…

Effects of Reflective Inquiry Instructional Technique on Students' Academic Achievement and Ability Level in Electronic Work Trade in Technical Colleges

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…

An Analysis of the Questions Proposed by Elementary Pre-Service Teachers When Designing Experimental Activities as Inquiry

ERIC Educational Resources Information Center

Cruz-Guzmán, Marta; García-Carmona, Antonio; Criado, Ana M.

2017-01-01

A qualitative study of an interpretative nature is presented of the topics that elementary pre-service teachers (EPTs) choose and the types of questions they propose when designing an experimental activity (ExA) as inquiry, after receiving explicit instruction about it. The participants in the study were 154 EPTs organised into small groups to…

Analysis of production responses to changing crude protein levels in lactating dairy cow diets when evaluated in continuous or change-over experimental designs

USDA-ARS?s Scientific Manuscript database

The objective of this study was to evaluate by meta-analysis the effect of experimental design on the production response functions obtained when changing crude protein levels in lactating dairy cow diets. The final database of studies that met the selection criteria contained 55 publications with 2...

The Effectiveness of Keyword-Based Instruction in Enhancing English Vocabulary Achievement and Retention of Intermediate Stage Pupils with Different Working Memory Capacities

ERIC Educational Resources Information Center

Al-Zahrani, Mona Abdullah Bakheet

2011-01-01

The current study aimed at investigating the effectiveness of keyword-based instruction in enhancing English vocabulary achievement and retention of intermediate stage pupils with different working memory capacities. The study adopted a quasi experimental design employing two groups (experimental and control). The design included an independent…

The Influence of Elective Surgery on Functional Health in Veterans with PTSD

DTIC Science & Technology

2012-12-21

elective surgery in veterans with PTSD. Design : A longitudinal, mixed method, quasi-experimental, nonequivalent control group study was conducted...longitudinal, mixed method, quasi-experimental, nonequivalent control group study was conducted. Methods and Sample: Physical and mental health...Methods Procedures." In Research design : qualitative, quantitative , and mixed methods approaches, 203-226. Thousand Oaks, Calif.: Sage Publications

Instructional Coaching at Selected Middle Schools in South Texas and Effects on Student Achievement

ERIC Educational Resources Information Center

Garcia, SantaPaula Gama; Jones, Don; Holland, Glenda; Mundy, Marie-Anne

2013-01-01

The purpose of this study was to compare two middle schools in one school district in south Texas to determine if presence or absence of instructional coaches has an effect on student achievement. The research design was a quantitative pre experimental study: a nonequivalent (posttest only) control group design in which the experimental group and…

Eliminating Health Disparities through Action on the Social Determinants of Health: A Systematic Review of Home Visiting in the United States, 2005-2015.

PubMed

Abbott, Laurie S; Elliott, Lynn T

2017-01-01

The purpose of this systematic literature review was to synthesize the results of transdisciplinary interventions designed with a home visit component in experimental and quasi-experimental studies having representative samples of racial and ethnic minorities. The design of this systematic review was adapted to include both experimental and quasi-experimental quantitative studies. The predetermined inclusion criteria were studies (a) having an experimental or quasi-experimental quantitative design, (b) having a home visit as a research component, (c) including a prevention research intervention strategy targeting health and/or safety issues, (d) conducted in the United States, (e) having representation (at least 30% in the total sample size) of one or more racial/ethnic minority, (f) available in full text, and (g) published in a peer-reviewed journal between January, 2005 and December, 2015. Thirty-nine articles were included in the review. There were 20 primary prevention, 5 secondary prevention, and 14 tertiary prevention intervention studies. Community and home visitation interventions by nurses can provide an effective means for mitigating social determinants of health by empowering people at risk for health disparities to avoid injury, maintain health, and prevent and manage existing disease. © 2016 Wiley Periodicals, Inc.

Hybrid computational and experimental approach for the study and optimization of mechanical components

NASA Astrophysics Data System (ADS)

Furlong, Cosme; Pryputniewicz, Ryszard J.

1998-05-01

Increased demands on the performance and efficiency of mechanical components impose challenges on their engineering design and optimization, especially when new and more demanding applications must be developed in relatively short periods of time while satisfying design objectives, as well as cost and manufacturability. In addition, reliability and durability must be taken into consideration. As a consequence, effective quantitative methodologies, computational and experimental, should be applied in the study and optimization of mechanical components. Computational investigations enable parametric studies and the determination of critical engineering design conditions, while experimental investigations, especially those using optical techniques, provide qualitative and quantitative information on the actual response of the structure of interest to the applied load and boundary conditions. We discuss a hybrid experimental and computational approach for investigation and optimization of mechanical components. The approach is based on analytical, computational, and experimental resolutions methodologies in the form of computational, noninvasive optical techniques, and fringe prediction analysis tools. Practical application of the hybrid approach is illustrated with representative examples that demonstrate the viability of the approach as an effective engineering tool for analysis and optimization.

The effects of incubation temperature and experimental design on heart rates of lizard embryos.

PubMed

Hulbert, Austin C; Mitchell, Timothy S; Hall, Joshua M; Guiffre, Cassia M; Douglas, Danielle C; Warner, Daniel A

2017-08-01

Many studies of phenotypic plasticity alter environmental conditions during embryonic development, yet only measure phenotypes at the neonatal stage (after embryonic development). However, measuring aspects of embryo physiology enhances our understanding of how environmental factors immediately affect embryos, which aids our understanding of developmental plasticity. While current research on reptile developmental plasticity has demonstrated that fluctuating incubation temperatures affect development differently than constant temperatures, most research on embryo physiology is still performed with constant temperature experiments. In this study, we noninvasively measured embryonic heart rates of the brown anole (Anolis sagrei), across ecologically relevant fluctuating temperatures. We incubated eggs under temperatures measured from potential nests in the field and examined how heart rates change through a diel cycle and throughout embryonic development. We also evaluated how experimental design (e.g., repeated vs. single measures designs, constant vs. fluctuating temperatures) and different protocols (e.g., removing eggs from incubators) might influence heart rate. We found that heart rates were correlated with daily temperature and increased through development. Our findings suggest that experimenters have reasonable flexibility in choosing an experimental design to address their questions; however, some aspects of design and protocol can potentially influence estimations of heart rates. Overall, we present the first ecologically relevant measures of anole embryonic heart rates and provide recommendations for experimental designs for future experiments. © 2017 Wiley Periodicals, Inc.

Computer-aided design and experimental investigation of a hydrodynamic device: the microwire electrode

PubMed

Fulian; Gooch; Fisher; Stevens; Compton

2000-08-01

The development and application of a new electrochemical device using a computer-aided design strategy is reported. This novel design is based on the flow of electrolyte solution past a microwire electrode situated centrally within a large duct. In the design stage, finite element simulations were employed to evaluate feasible working geometries and mass transport rates. The computer-optimized designs were then exploited to construct experimental devices. Steady-state voltammetric measurements were performed for a reversible one-electron-transfer reaction to establish the experimental relationship between electrolysis current and solution velocity. The experimental results are compared to those predicted numerically, and good agreement is found. The numerical studies are also used to establish an empirical relationship between the mass transport limited current and the volume flow rate, providing a simple and quantitative alternative for workers who would prefer to exploit this device without the need to develop the numerical aspects.

[Research-oriented experimental course of plant cell and gene engineering for undergraduates].

PubMed

Xiaofei, Lin; Rong, Zheng; Morigen, Morigen

2015-04-01

Research-oriented comprehensive experimental course for undergraduates is an important part for their training of innovation. We established an optional course of plant cell and gene engineering for undergraduates using our research platform. The course is designed to study the cellular and molecular basis and experimental techniques for plant tissue culture, isolation and culture of protoplast, genetic transformation, and screening and identification of transgenic plants. To develop undergraduates' ability in experimental design and operation, and inspire their interest in scientific research and innovation consciousness, we integrated experimental teaching and practice in plant genetic engineering on the tissue, cellular, and molecular levels. Students in the course practiced an experimental teaching model featured by two-week teaching of principles, independent experimental design and bench work, and ready-to-access laboratory. In this paper, we describe the contents, methods, evaluation system and a few issues to be solved in this course, as well as the general application and significance of the research-oriented experimental course in reforming undergraduates' teaching and training innovative talents.

Marginal Biotin Deficiency Can Be Induced Experimentally in Humans Using a Cost-Effective Outpatient Design123

PubMed Central

Stratton, Shawna L.; Henrich, Cindy L.; Matthews, Nell I.; Bogusiewicz, Anna; Dawson, Amanda M.; Horvath, Thomas D.; Owen, Suzanne N.; Boysen, Gunnar; Moran, Jeffery H.; Mock, Donald M.

2012-01-01

To date, marginal, asymptomatic biotin deficiency has been successfully induced experimentally by the use of labor-intensive inpatient designs requiring rigorous dietary control. We sought to determine if marginal biotin deficiency could be induced in humans in a less expensive outpatient design incorporating a self-selected, mixed general diet. We sought to examine the efficacy of three outpatient study designs: two based on oral avidin dosing and one based on a diet high in undenatured egg white for a period of 28 d. In study design 1, participants (n = 4; 3 women) received avidin in capsules with a biotin binding capacity of 7 times the estimated dietary biotin intake of a typical self-selected diet. In study design 2, participants (n = 2; 2 women) received double the amount of avidin capsules (14 times the estimated dietary biotin intake). In study design 3, participants (n = 5; 3 women) consumed egg-white beverages containing avidin with a biotin binding capacity of 7 times the estimated dietary biotin intake. Established indices of biotin status [lymphocyte propionyl-CoA carboxylase activity; urinary excretion of 3-hydroxyisovaleric acid, 3-hydroxyisovaleryl carnitine (3HIA-carnitine), and biotin; and plasma concentration of 3HIA-carnitine] indicated that study designs 1 and 2 were not effective in inducing marginal biotin deficiency, but study design 3 was as effective as previous inpatient study designs that induced deficiency by egg-white beverage. Marginal biotin deficiency can be induced experimentally by using a cost-effective outpatient design by avidin delivery in egg-white beverages. This design should be useful to the broader nutritional research community. PMID:22157538

Making Controlled Experimentation More Informative in Inquiry Investigations

ERIC Educational Resources Information Center

McElhaney, Kevin Wei Hong

2010-01-01

This dissertation incorporates three studies that examine how the design of inquiry based science instruction, dynamic visualizations, and guidance for experimentation contribute to physics students' understanding of science. I designed a week-long, technology-enhanced inquiry module on car collisions that logs students' interactions with a…

RATES OF REACTION AND PROCESS DESIGN DATA FOR THE HYDROCARB PROCESS

EPA Science Inventory

The report provides experimental and process design data in support of studies for developing the coprocessing of fossil fuels with biomass by the Hydrocarb process. The experimental work includes the hydropyrolysis of biomass and the thermal decomposition of methane in a 2.44 m ...

A Computational/Experimental Study of Two Optimized Supersonic Transport Designs and the Reference H Baseline

NASA Technical Reports Server (NTRS)

Cliff, Susan E.; Baker, Timothy J.; Hicks, Raymond M.; Reuther, James J.

1999-01-01

Two supersonic transport configurations designed by use of non-linear aerodynamic optimization methods are compared with a linearly designed baseline configuration. One optimized configuration, designated Ames 7-04, was designed at NASA Ames Research Center using an Euler flow solver, and the other, designated Boeing W27, was designed at Boeing using a full-potential method. The two optimized configurations and the baseline were tested in the NASA Langley Unitary Plan Supersonic Wind Tunnel to evaluate the non-linear design optimization methodologies. In addition, the experimental results are compared with computational predictions for each of the three configurations from the Enter flow solver, AIRPLANE. The computational and experimental results both indicate moderate to substantial performance gains for the optimized configurations over the baseline configuration. The computed performance changes with and without diverters and nacelles were in excellent agreement with experiment for all three models. Comparisons of the computational and experimental cruise drag increments for the optimized configurations relative to the baseline show excellent agreement for the model designed by the Euler method, but poorer comparisons were found for the configuration designed by the full-potential code.

76 FR 338 - Notice of Proposed Information Collection Requests

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-04

... feasibility of a promising practices study of Upward Bound that uses a rigorous quasi-experimental design. The design and feasibility report will develop a set of design options for conducting a study of Upward Bound and examine their applicability to studies of other TRIO programs. If a rigorous evaluation design...

Joint Services Electronics Program.

DTIC Science & Technology

1983-09-30

environment. The research is under three interrelated heads: (1) algebraic Methodologies for Control Systems design , both linear and non -linear, (2) robust...properties of the device. After study of these experimental results, we plan to design a millimeter- wave version of the Gunn device. This will...appropriate dose discretization level for an adju- stable width beam. 2) Experimental Device Fabrication In a collaborative effort with the IC design group

Promoting Experimental Problem-solving Ability in Sixth-grade Students Through Problem-oriented Teaching of Ecology: Findings of an intervention study in a complex domain

NASA Astrophysics Data System (ADS)

Roesch, Frank; Nerb, Josef; Riess, Werner

2015-03-01

Our study investigated whether problem-oriented designed ecology lessons with phases of direct instruction and of open experimentation foster the development of cross-domain and domain-specific components of experimental problem-solving ability better than conventional lessons in science. We used a paper-and-pencil test to assess students' abilities in a quasi-experimental intervention study utilizing a pretest/posttest control-group design (N = 340; average performing sixth-grade students). The treatment group received lessons on forest ecosystems consistent with the principle of education for sustainable development. This learning environment was expected to help students enhance their ecological knowledge and their theoretical and methodological experimental competencies. Two control groups received either the teachers' usual lessons on forest ecosystems or non-specific lessons on other science topics. We found that the treatment promoted specific components of experimental problem-solving ability (generating epistemic questions, planning two-factorial experiments, and identifying correct experimental controls). However, the observed effects were small, and awareness for aspects of higher ecological experimental validity was not promoted by the treatment.

A Quasi-Experimental Study on Using Short Stories: Statistical and Inferential Analyses on the Non-English Major University Students' Speaking and Writing Achievements

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…

Problem Implementation as a Lever for Change: An Experimental Study of the Effects of a Professional Development Program on Students' Mathematics Learning

ERIC Educational Resources Information Center

Santagata, Rossella; Kersting, Nicole; Givvin, Karen B.; Stigler, James W.

2011-01-01

This study investigates, through an experimental design, the effectiveness of a professional development program on teacher knowledge and practices and on student learning. The program consisted of a series of video-based modules designed to respond to needs of U.S. teachers, as highlighted by findings from the 1999 Third International Mathematics…

The Effect of Tonality and Rhythm on Memory Recall in Elementary General Education Classrooms: A Quasi-Experimental Study

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.…

Experimental Study and Computational Simulations of Key Pebble Bed Thermo-mechanics Issues for Design and Safety

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

Tokuhiro, Akira; Potirniche, Gabriel; Cogliati, Joshua

2014-07-08

An experimental and computational study, consisting of modeling and simulation (M&S), of key thermal-mechanical issues affecting the design and safety of pebble-bed (PB) reactors was conducted. The objective was to broaden understanding and experimentally validate thermal-mechanic phenomena of nuclear grade graphite, specifically, spheres in frictional contact as anticipated in the bed under reactor relevant pressures and temperatures. The contact generates graphite dust particulates that can subsequently be transported into the flowing gaseous coolent. Under postulated depressurization transients and with the potential for leaked fission products to be adsorbed onto graphite 'dust', there is the potential for fission products to escapemore » from the primary volume. This is a design safety concern. Furthermore, earlier safety assessment identified the distinct possibility for the dispersed dust to combust in contact with air if sufficient conditions are met. Both of these phenomena were noted as important to design review and containing uncertainty to warrant study. The team designed and conducted two separate effects tests to study and benchmark the potential dust-generation rate, as well as study the conditions under which a dust explosion may occure in a standardized, instrumented explosion chamber.« less

Diet composition as a source of variation in experimental animal models of cancer cachexia.

PubMed

Giles, Kaitlin; Guan, Chen; Jagoe, Thomas R; Mazurak, Vera

2016-05-01

A variety of experimental animal models are used extensively to study mechanisms underlying cancer cachexia, and to identify potential treatments. The important potential confounding effect of dietary composition and intake used in many preclinical studies of cancer cachexia is frequently overlooked. Dietary designs applied in experimental studies should maximize the applicability to human cancer cachexia, meeting the essential requirements of the species used in the study, matched between treatment and control groups as well as also being generally similar to human consumption. A literature review of scientific studies using animal models of cancer and cancer cachexia with dietary interventions was performed. Studies that investigated interventions using lipid sources were selected as the focus of discussion. The search revealed a number of nutrient intervention studies (n = 44), with the majority including n-3 fatty acids (n = 16), mainly eicosapentaenoic acid and/or docosahexaenoic acid. A review of the literature revealed that the majority of studies do not provide information about dietary design; food intake or pair-feeding is rarely reported. Further, there is a lack of standardization in dietary design, content, source, and overall composition in animal models of cancer cachexia. A model is proposed with the intent of guiding dietary design in preclinical studies to enable comparisons of dietary treatments within the same study, translation across different study designs, as well as application to human nutrient intakes. The potential for experimental endpoints to be affected by variations in food intake, macronutrient content, and diet composition is likely. Diet content and composition should be reported, and food intake assessed. Minimum standards for diet definition in cachexia studies would improve reproducibility of pre-clinical studies and aid the interpretation and translation of results to humans with cancer.

Diet composition as a source of variation in experimental animal models of cancer cachexia

PubMed Central

Giles, Kaitlin; Guan, Chen; Jagoe, Thomas R.

2015-01-01

Abstract Background A variety of experimental animal models are used extensively to study mechanisms underlying cancer cachexia, and to identify potential treatments. The important potential confounding effect of dietary composition and intake used in many preclinical studies of cancer cachexia is frequently overlooked. Dietary designs applied in experimental studies should maximize the applicability to human cancer cachexia, meeting the essential requirements of the species used in the study, matched between treatment and control groups as well as also being generally similar to human consumption. Methods A literature review of scientific studies using animal models of cancer and cancer cachexia with dietary interventions was performed. Studies that investigated interventions using lipid sources were selected as the focus of discussion. Results The search revealed a number of nutrient intervention studies (n = 44), with the majority including n‐3 fatty acids (n = 16), mainly eicosapentaenoic acid and/or docosahexaenoic acid. A review of the literature revealed that the majority of studies do not provide information about dietary design; food intake or pair‐feeding is rarely reported. Further, there is a lack of standardization in dietary design, content, source, and overall composition in animal models of cancer cachexia. A model is proposed with the intent of guiding dietary design in preclinical studies to enable comparisons of dietary treatments within the same study, translation across different study designs, as well as application to human nutrient intakes. Conclusion The potential for experimental endpoints to be affected by variations in food intake, macronutrient content, and diet composition is likely. Diet content and composition should be reported, and food intake assessed. Minimum standards for diet definition in cachexia studies would improve reproducibility of pre‐clinical studies and aid the interpretation and translation of results to humans with cancer. PMID:27493865

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…

Reverse design and characteristic study of multi-range HMCVT

NASA Astrophysics Data System (ADS)

Zhu, Zhen; Chen, Long; Zeng, Falin

2017-09-01

The reduction of fuel consumption and increase of transmission efficiency is one of the key problems of the agricultural machinery. Many promising technologies such as hydromechanical continuously variable transmissions (HMCVT) are the focus of research and investments, but there is little technical documentation that describes the design principle and presents the design parameters. This paper presents the design idea and characteristic study of HMCVT, in order to find out the suitable scheme for the big horsepower tractors. Analyzed the kinematics and dynamics of a large horsepower tractor, according to the characteristic parameters, a hydro-mechanical continuously variable transmission has been designed. Compared with the experimental curves and theoretical curves of the stepless speed regulation of transmission, the experimental result illustrates the rationality of the design scheme.

Using Dynamic Geometry Software to Improve Eight Grade Students' Understanding of Transformation Geometry

ERIC Educational Resources Information Center

Guven, Bulent

2012-01-01

This study examines the effect of dynamic geometry software (DGS) on students' learning of transformation geometry. A pre- and post-test quasi-experimental design was used. Participants in the study were 68 eighth grade students (36 in the experimental group and 32 in the control group). While the experimental group students were studying the…

Optical workstation with concurrent, independent multiphoton imaging and experimental laser microbeam capabilities

PubMed Central

Wokosin, David L.; Squirrell, Jayne M.; Eliceiri, Kevin W.; White, John G.

2008-01-01

Experimental laser microbeam techniques have become established tools for studying living specimens. A steerable, focused laser beam may be used for a variety of experimental manipulations such as laser microsurgery, optical trapping, localized photolysis of caged bioactive probes, and patterned photobleaching. Typically, purpose-designed experimental systems have been constructed for each of these applications. In order to assess the consequences of such experimental optical interventions, long-term, microscopic observation of the specimen is often required. Multiphoton excitation, because of its ability to obtain high-contrast images from deep within a specimen with minimal phototoxic effects, is a preferred technique for in vivo imaging. An optical workstation is described that combines the functionality of an experimental optical microbeam apparatus with a sensitive multiphoton imaging system designed for use with living specimens. Design considerations are discussed and examples of ongoing biological applications are presented. The integrated optical workstation concept offers advantages in terms of flexibility and versatility relative to systems implemented with separate imaging and experimental components. PMID:18607511

Optical workstation with concurrent, independent multiphoton imaging and experimental laser microbeam capabilities

NASA Astrophysics Data System (ADS)

Wokosin, David L.; Squirrell, Jayne M.; Eliceiri, Kevin W.; White, John G.

2003-01-01

Experimental laser microbeam techniques have become established tools for studying living specimens. A steerable, focused laser beam may be used for a variety of experimental manipulations such as laser microsurgery, optical trapping, localized photolysis of caged bioactive probes, and patterned photobleaching. Typically, purpose-designed experimental systems have been constructed for each of these applications. In order to assess the consequences of such experimental optical interventions, long-term, microscopic observation of the specimen is often required. Multiphoton excitation, because of its ability to obtain high-contrast images from deep within a specimen with minimal phototoxic effects, is a preferred technique for in vivo imaging. An optical workstation is described that combines the functionality of an experimental optical microbeam apparatus with a sensitive multiphoton imaging system designed for use with living specimens. Design considerations are discussed and examples of ongoing biological applications are presented. The integrated optical workstation concept offers advantages in terms of flexibility and versatility relative to systems implemented with separate imaging and experimental components.

What are you trying to learn? Study designs and the appropriate analysis for your research question

USDA-ARS?s Scientific Manuscript database

One fundamental necessity in the entire process of a well-performed study is the experimental design. A well-designed study can help researchers understand and have confidence in their results and analyses, and additionally the agreement or disagreement with the stated hypothesis. This well-designed...

Investigation of a 0.6 hub-tip radius-ratio transonic turbine designed for secondary-flow study I : design and experimental performance of standard turbine

NASA Technical Reports Server (NTRS)

Rohlik, Harold E; Wintucky, William T; Scibbe, Herbert W

1957-01-01

Detailed design information including overall performance parameters, velocity diagrams, and blade surface velocities is presented. Experimental performance includes maps based on rating as well as total-pressure ratios showing the effect of exit whirl. Also included are results of surveys at the stator exit and downstream of the rotor at design speed and specific work. This information will be used as a standard for comparison with subsequent secondary-flow work.

Partial Least Squares with Structured Output for Modelling the Metabolomics Data Obtained from Complex Experimental Designs: A Study into the Y-Block Coding.

PubMed

Xu, Yun; Muhamadali, Howbeer; Sayqal, Ali; Dixon, Neil; Goodacre, Royston

2016-10-28

Partial least squares (PLS) is one of the most commonly used supervised modelling approaches for analysing multivariate metabolomics data. PLS is typically employed as either a regression model (PLS-R) or a classification model (PLS-DA). However, in metabolomics studies it is common to investigate multiple, potentially interacting, factors simultaneously following a specific experimental design. Such data often cannot be considered as a "pure" regression or a classification problem. Nevertheless, these data have often still been treated as a regression or classification problem and this could lead to ambiguous results. In this study, we investigated the feasibility of designing a hybrid target matrix Y that better reflects the experimental design than simple regression or binary class membership coding commonly used in PLS modelling. The new design of Y coding was based on the same principle used by structural modelling in machine learning techniques. Two real metabolomics datasets were used as examples to illustrate how the new Y coding can improve the interpretability of the PLS model compared to classic regression/classification coding.

Modeling flows of heterogeneous media in pipelines when substantiating operating conditions of hydrocarbon field transportation systems

NASA Astrophysics Data System (ADS)

Dudin, S. M.; Novitskiy, D. V.

2018-05-01

The works of researchers at VNIIgaz, Giprovostokneft, Kuibyshev NIINP, Grozny Petroleum Institute, etc., are devoted to modeling heterogeneous medium flows in pipelines under laboratory conditions. In objective consideration, the empirical relationships obtained and the calculation procedures for pipelines transporting multiphase products are a bank of experimental data on the problem of pipeline transportation of multiphase systems. Based on the analysis of the published works, the main design requirements for experimental installations designed to study the flow regimes of gas-liquid flows in pipelines were formulated, which were taken into account by the authors when creating the experimental stand. The article describes the results of experimental studies of the flow regimes of a gas-liquid mixture in a pipeline, and also gives a methodological description of the experimental installation. Also the article describes the software of the experimental scientific and educational stand developed with the participation of the authors.

Optimal Objective-Based Experimental Design for Uncertain Dynamical Gene Networks with Experimental Error.

PubMed

Mohsenizadeh, Daniel N; Dehghannasiri, Roozbeh; Dougherty, Edward R

2018-01-01

In systems biology, network models are often used to study interactions among cellular components, a salient aim being to develop drugs and therapeutic mechanisms to change the dynamical behavior of the network to avoid undesirable phenotypes. Owing to limited knowledge, model uncertainty is commonplace and network dynamics can be updated in different ways, thereby giving multiple dynamic trajectories, that is, dynamics uncertainty. In this manuscript, we propose an experimental design method that can effectively reduce the dynamics uncertainty and improve performance in an interaction-based network. Both dynamics uncertainty and experimental error are quantified with respect to the modeling objective, herein, therapeutic intervention. The aim of experimental design is to select among a set of candidate experiments the experiment whose outcome, when applied to the network model, maximally reduces the dynamics uncertainty pertinent to the intervention objective.

Experimental study of adaptive pointing and tracking for large flexible space structures

NASA Technical Reports Server (NTRS)

Boussalis, D.; Bayard, D. S.; Ih, C.; Wang, S. J.; Ahmed, A.

1991-01-01

This paper describes an experimental study of adaptive pointing and tracking control for flexible spacecraft conducted on a complex ground experiment facility. The algorithm used in this study is based on a multivariable direct model reference adaptive control law. Several experimental validation studies were performed earlier using this algorithm for vibration damping and robust regulation, with excellent results. The current work extends previous studies by addressing the pointing and tracking problem. As is consistent with an adaptive control framework, the plant is assumed to be poorly known to the extent that only system level knowledge of its dynamics is available. Explicit bounds on the steady-state pointing error are derived as functions of the adaptive controller design parameters. It is shown that good tracking performance can be achieved in an experimental setting by adjusting adaptive controller design weightings according to the guidelines indicated by the analytical expressions for the error.

A comparison of two experimental design approaches in applying conjoint analysis in patient-centered outcomes research: a randomized trial.

PubMed

Kinter, Elizabeth T; Prior, Thomas J; Carswell, Christopher I; Bridges, John F P

2012-01-01

While the application of conjoint analysis and discrete-choice experiments in health are now widely accepted, a healthy debate exists around competing approaches to experimental design. There remains, however, a paucity of experimental evidence comparing competing design approaches and their impact on the application of these methods in patient-centered outcomes research. Our objectives were to directly compare the choice-model parameters and predictions of an orthogonal and a D-efficient experimental design using a randomized trial (i.e., an experiment on experiments) within an application of conjoint analysis studying patient-centered outcomes among outpatients diagnosed with schizophrenia in Germany. Outpatients diagnosed with schizophrenia were surveyed and randomized to receive choice tasks developed using either an orthogonal or a D-efficient experimental design. The choice tasks elicited judgments from the respondents as to which of two patient profiles (varying across seven outcomes and process attributes) was preferable from their own perspective. The results from the two survey designs were analyzed using the multinomial logit model, and the resulting parameter estimates and their robust standard errors were compared across the two arms of the study (i.e., the orthogonal and D-efficient designs). The predictive performances of the two resulting models were also compared by computing their percentage of survey responses classified correctly, and the potential for variation in scale between the two designs of the experiments was tested statistically and explored graphically. The results of the two models were statistically identical. No difference was found using an overall chi-squared test of equality for the seven parameters (p = 0.69) or via uncorrected pairwise comparisons of the parameter estimates (p-values ranged from 0.30 to 0.98). The D-efficient design resulted in directionally smaller standard errors for six of the seven parameters, of which only two were statistically significant, and no differences were found in the observed D-efficiencies of their standard errors (p = 0.62). The D-efficient design resulted in poorer predictive performance, but this was not significant (p = 0.73); there was some evidence that the parameters of the D-efficient design were biased marginally towards the null. While no statistical difference in scale was detected between the two designs (p = 0.74), the D-efficient design had a higher relative scale (1.06). This could be observed when the parameters were explored graphically, as the D-efficient parameters were lower. Our results indicate that orthogonal and D-efficient experimental designs have produced results that are statistically equivalent. This said, we have identified several qualitative findings that speak to the potential differences in these results that may have been statistically identified in a larger sample. While more comparative studies focused on the statistical efficiency of competing design strategies are needed, a more pressing research problem is to document the impact the experimental design has on respondent efficiency.

Design of a factorial experiment with randomization restrictions to assess medical device performance on vascular tissue

PubMed Central

2011-01-01

Background Energy-based surgical scalpels are designed to efficiently transect and seal blood vessels using thermal energy to promote protein denaturation and coagulation. Assessment and design improvement of ultrasonic scalpel performance relies on both in vivo and ex vivo testing. The objective of this work was to design and implement a robust, experimental test matrix with randomization restrictions and predictive statistical power, which allowed for identification of those experimental variables that may affect the quality of the seal obtained ex vivo. Methods The design of the experiment included three factors: temperature (two levels); the type of solution used to perfuse the artery during transection (three types); and artery type (two types) resulting in a total of twelve possible treatment combinations. Burst pressures of porcine carotid and renal arteries sealed ex vivo were assigned as the response variable. Results The experimental test matrix was designed and carried out as a split-plot experiment in order to assess the contributions of several variables and their interactions while accounting for randomization restrictions present in the experimental setup. The statistical software package SAS was utilized and PROC MIXED was used to account for the randomization restrictions in the split-plot design. The combination of temperature, solution, and vessel type had a statistically significant impact on seal quality. Conclusions The design and implementation of a split-plot experimental test-matrix provided a mechanism for addressing the existing technical randomization restrictions of ex vivo ultrasonic scalpel performance testing, while preserving the ability to examine the potential effects of independent factors or variables. This method for generating the experimental design and the statistical analyses of the resulting data are adaptable to a wide variety of experimental problems involving large-scale tissue-based studies of medical or experimental device efficacy and performance. PMID:21599963

Impact of Thematic Approach on Communication Skill in Preschool

ERIC Educational Resources Information Center

Ashokan, Varun; Venugopal, Kalpana

2016-01-01

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

Teaching experimental design.

PubMed

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.

Experimental design to evaluate directed adaptive mutation in Mammalian cells.

PubMed

Bordonaro, Michael; Chiaro, Christopher R; May, Tobias

2014-12-09

We describe the experimental design for a methodological approach to determine whether directed adaptive mutation occurs in mammalian cells. Identification of directed adaptive mutation would have profound practical significance for a wide variety of biomedical problems, including disease development and resistance to treatment. In adaptive mutation, the genetic or epigenetic change is not random; instead, the presence and type of selection influences the frequency and character of the mutation event. Adaptive mutation can contribute to the evolution of microbial pathogenesis, cancer, and drug resistance, and may become a focus of novel therapeutic interventions. Our experimental approach was designed to distinguish between 3 types of mutation: (1) random mutations that are independent of selective pressure, (2) undirected adaptive mutations that arise when selective pressure induces a general increase in the mutation rate, and (3) directed adaptive mutations that arise when selective pressure induces targeted mutations that specifically influence the adaptive response. The purpose of this report is to introduce an experimental design and describe limited pilot experiment data (not to describe a complete set of experiments); hence, it is an early report. An experimental design based on immortalization of mouse embryonic fibroblast cells is presented that links clonal cell growth to reversal of an inactivating polyadenylation site mutation. Thus, cells exhibit growth only in the presence of both the countermutation and an inducing agent (doxycycline). The type and frequency of mutation in the presence or absence of doxycycline will be evaluated. Additional experimental approaches would determine whether the cells exhibit a generalized increase in mutation rate and/or whether the cells show altered expression of error-prone DNA polymerases or of mismatch repair proteins. We performed the initial stages of characterizing our system and have limited preliminary data from several pilot experiments. Cell growth and DNA sequence data indicate that we have identified a cell clone that exhibits several suitable characteristics, although further study is required to identify a more optimal cell clone. The experimental approach is based on a quantum biological model of basis-dependent selection describing a novel mechanism of adaptive mutation. This project is currently inactive due to lack of funding. However, consistent with the objective of early reports, we describe a proposed study that has not produced publishable results, but is worthy of report because of the hypothesis, experimental design, and protocols. We outline the project's rationale and experimental design, with its strengths and weaknesses, to stimulate discussion and analysis, and lay the foundation for future studies in this field.

Prospective power calculations for the Four Lab study of a multigenerational reproductive/developmental toxicity rodent bioassay using a complex mixture of disinfection by-products in the low-response region.

PubMed

Dingus, Cheryl A; Teuschler, Linda K; Rice, Glenn E; Simmons, Jane Ellen; Narotsky, Michael G

2011-10-01

In complex mixture toxicology, there is growing emphasis on testing environmentally representative doses that improve the relevance of results for health risk assessment, but are typically much lower than those used in traditional toxicology studies. Traditional experimental designs with typical sample sizes may have insufficient statistical power to detect effects caused by environmentally relevant doses. Proper study design, with adequate statistical power, is critical to ensuring that experimental results are useful for environmental health risk assessment. Studies with environmentally realistic complex mixtures have practical constraints on sample concentration factor and sample volume as well as the number of animals that can be accommodated. This article describes methodology for calculation of statistical power for non-independent observations for a multigenerational rodent reproductive/developmental bioassay. The use of the methodology is illustrated using the U.S. EPA's Four Lab study in which rodents were exposed to chlorinated water concentrates containing complex mixtures of drinking water disinfection by-products. Possible experimental designs included two single-block designs and a two-block design. Considering the possible study designs and constraints, a design of two blocks of 100 females with a 40:60 ratio of control:treated animals and a significance level of 0.05 yielded maximum prospective power (~90%) to detect pup weight decreases, while providing the most power to detect increased prenatal loss.

Prospective Power Calculations for the Four Lab Study of A Multigenerational Reproductive/Developmental Toxicity Rodent Bioassay Using A Complex Mixture of Disinfection By-Products in the Low-Response Region

PubMed Central

Dingus, Cheryl A.; Teuschler, Linda K.; Rice, Glenn E.; Simmons, Jane Ellen; Narotsky, Michael G.

2011-01-01

In complex mixture toxicology, there is growing emphasis on testing environmentally representative doses that improve the relevance of results for health risk assessment, but are typically much lower than those used in traditional toxicology studies. Traditional experimental designs with typical sample sizes may have insufficient statistical power to detect effects caused by environmentally relevant doses. Proper study design, with adequate statistical power, is critical to ensuring that experimental results are useful for environmental health risk assessment. Studies with environmentally realistic complex mixtures have practical constraints on sample concentration factor and sample volume as well as the number of animals that can be accommodated. This article describes methodology for calculation of statistical power for non-independent observations for a multigenerational rodent reproductive/developmental bioassay. The use of the methodology is illustrated using the U.S. EPA’s Four Lab study in which rodents were exposed to chlorinated water concentrates containing complex mixtures of drinking water disinfection by-products. Possible experimental designs included two single-block designs and a two-block design. Considering the possible study designs and constraints, a design of two blocks of 100 females with a 40:60 ratio of control:treated animals and a significance level of 0.05 yielded maximum prospective power (~90%) to detect pup weight decreases, while providing the most power to detect increased prenatal loss. PMID:22073030

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

ERIC Educational Resources Information Center

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

2010-01-01

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

21 CFR 514.117 - Adequate and well-controlled studies.

Code of Federal Regulations, 2011 CFR

2011-04-01

... experimental units. When the effect of such variables is accounted for by an appropriate design, and when... and well-controlled study should provide sufficient details of study design, conduct, and analysis to... the new animal drug used in the study. (4) The study uses a design that permits a valid comparison...

21 CFR 514.117 - Adequate and well-controlled studies.

Code of Federal Regulations, 2012 CFR

2012-04-01

... experimental units. When the effect of such variables is accounted for by an appropriate design, and when... and well-controlled study should provide sufficient details of study design, conduct, and analysis to... the new animal drug used in the study. (4) The study uses a design that permits a valid comparison...

21 CFR 514.117 - Adequate and well-controlled studies.

Code of Federal Regulations, 2014 CFR

2014-04-01

... experimental units. When the effect of such variables is accounted for by an appropriate design, and when... and well-controlled study should provide sufficient details of study design, conduct, and analysis to... the new animal drug used in the study. (4) The study uses a design that permits a valid comparison...

21 CFR 514.117 - Adequate and well-controlled studies.

Code of Federal Regulations, 2013 CFR

2013-04-01

... experimental units. When the effect of such variables is accounted for by an appropriate design, and when... and well-controlled study should provide sufficient details of study design, conduct, and analysis to... the new animal drug used in the study. (4) The study uses a design that permits a valid comparison...

21 CFR 514.117 - Adequate and well-controlled studies.

Code of Federal Regulations, 2010 CFR

2010-04-01

... experimental units. When the effect of such variables is accounted for by an appropriate design, and when... and well-controlled study should provide sufficient details of study design, conduct, and analysis to... the new animal drug used in the study. (4) The study uses a design that permits a valid comparison...

Bioremediation of chlorpyrifos contaminated soil by two phase bioslurry reactor: Processes evaluation and optimization by Taguchi's design of experimental (DOE) methodology.

PubMed

Pant, Apourv; Rai, J P N

2018-04-15

Two phase bioreactor was constructed, designed and developed to evaluate the chlorpyrifos remediation. Six biotic and abiotic factors (substrate-loading rate, slurry phase pH, slurry phase dissolved oxygen (DO), soil water ratio, temperature and soil micro flora load) were evaluated by design of experimental (DOE) methodology employing Taguchi's orthogonal array (OA). The selected six factors were considered at two levels L-8 array (2^7, 15 experiments) in the experimental design. The optimum operating conditions obtained from the methodology showed enhanced chlorpyrifos degradation from 283.86µg/g to 955.364µg/g by overall 70.34% of enhancement. In the present study, with the help of few well defined experimental parameters a mathematical model was constructed to understand the complex bioremediation process and optimize the approximate parameters upto great accuracy. Copyright © 2017 Elsevier Inc. All rights reserved.

A Discourse on Human Systems Integration

DTIC Science & Technology

2010-09-01

criterion for one of the study tasks. 2. Research Design This was a mixed methods study. The first-phase quantitative portion of the study...used a quasi-experimental, posttest-only with nonequivalent groups design . The independent variables were defined as follows: • The categorical... Research Design ...............................................................................287 3. Instruments

Task design influences prosociality in captive chimpanzees (Pan troglodytes).

PubMed

House, Bailey R; Silk, Joan B; Lambeth, Susan P; Schapiro, Steven J

2014-01-01

Chimpanzees confer benefits on group members, both in the wild and in captive populations. Experimental studies of how animals allocate resources can provide useful insights about the motivations underlying prosocial behavior, and understanding the relationship between task design and prosocial behavior provides an important foundation for future research exploring these animals' social preferences. A number of studies have been designed to assess chimpanzees' preferences for outcomes that benefit others (prosocial preferences), but these studies vary greatly in both the results obtained and the methods used, and in most cases employ procedures that reduce critical features of naturalistic social interactions, such as partner choice. The focus of the current study is on understanding the link between experimental methodology and prosocial behavior in captive chimpanzees, rather than on describing these animals' social motivations themselves. We introduce a task design that avoids isolating subjects and allows them to freely decide whether to participate in the experiment. We explore key elements of the methods utilized in previous experiments in an effort to evaluate two possibilities that have been offered to explain why different experimental designs produce different results: (a) chimpanzees are less likely to deliver food to others when they obtain food for themselves, and (b) evidence of prosociality may be obscured by more "complex" experimental apparatuses (e.g., those including more components or alternative choices). Our results suggest that the complexity of laboratory tasks may generate observed variation in prosocial behavior in laboratory experiments, and highlights the need for more naturalistic research designs while also providing one example of such a paradigm.

Task Design Influences Prosociality in Captive Chimpanzees (Pan troglodytes)

PubMed Central

House, Bailey R.; Silk, Joan B.; Lambeth, Susan P.; Schapiro, Steven J.

2014-01-01

Chimpanzees confer benefits on group members, both in the wild and in captive populations. Experimental studies of how animals allocate resources can provide useful insights about the motivations underlying prosocial behavior, and understanding the relationship between task design and prosocial behavior provides an important foundation for future research exploring these animals' social preferences. A number of studies have been designed to assess chimpanzees' preferences for outcomes that benefit others (prosocial preferences), but these studies vary greatly in both the results obtained and the methods used, and in most cases employ procedures that reduce critical features of naturalistic social interactions, such as partner choice. The focus of the current study is on understanding the link between experimental methodology and prosocial behavior in captive chimpanzees, rather than on describing these animals' social motivations themselves. We introduce a task design that avoids isolating subjects and allows them to freely decide whether to participate in the experiment. We explore key elements of the methods utilized in previous experiments in an effort to evaluate two possibilities that have been offered to explain why different experimental designs produce different results: (a) chimpanzees are less likely to deliver food to others when they obtain food for themselves, and (b) evidence of prosociality may be obscured by more “complex” experimental apparatuses (e.g., those including more components or alternative choices). Our results suggest that the complexity of laboratory tasks may generate observed variation in prosocial behavior in laboratory experiments, and highlights the need for more naturalistic research designs while also providing one example of such a paradigm. PMID:25191860

Optimal Experiment Design for Thermal Characterization of Functionally Graded Materials

NASA Technical Reports Server (NTRS)

Cole, Kevin D.

2003-01-01

The purpose of the project was to investigate methods to accurately verify that designed , materials meet thermal specifications. The project involved heat transfer calculations and optimization studies, and no laboratory experiments were performed. One part of the research involved study of materials in which conduction heat transfer predominates. Results include techniques to choose among several experimental designs, and protocols for determining the optimum experimental conditions for determination of thermal properties. Metal foam materials were also studied in which both conduction and radiation heat transfer are present. Results of this work include procedures to optimize the design of experiments to accurately measure both conductive and radiative thermal properties. Detailed results in the form of three journal papers have been appended to this report.

Small Independent Action Force (SIAF), Vegetation Classification Study

DTIC Science & Technology

1976-03-01

CONTENTS I. INTRODUCTION 8 II. BACKGBCUND and PORPOSE 10 III. METHOD 16 A. EXPERIMENTAL DESIGN 16 B. SUBJECTS .’ 17 C. APPARATUS 17 D. STIMULUS...reliability of subjects will be obtained. 15 III. METHOD A. EXPERIMENTAL DESIGN . The experiment involved a continous stream of stimuli. Phase 1 stimuli...the attribute to be scaled. The subjecr must designate one of the pair as greater. No equality judgments are permitted. In order to obtain data from

Sensitive Metamaterial Sensor for Distinction of Authentic and Inauthentic Fuel Samples

NASA Astrophysics Data System (ADS)

Tümkaya, Mehmet Ali; Dinçer, Furkan; Karaaslan, Muharrem; Sabah, Cumali

2017-08-01

A metamaterial-based sensor has been realized to distinguish authentic and inauthentic fuel samples in the microwave frequency regime. Unlike the many studies in literature on metamaterial-based sensor applications, this study focuses on a compact metamaterial-based sensor operating in the X-band frequency range. Firstly, electromagnetic properties of authentic and inauthentic fuel samples were obtained experimentally in a laboratory environment. Secondly, these experimental results were used to design and create a highly efficient metamaterial-based sensor with easy fabrication characteristics and simple design structure. The experimental results for the sensor were in good agreement with the numerical ones. The proposed sensor offers a more efficient design and can be used to detect fuel and multiple other liquids in various application fields from medical to military areas in several frequency regimes.

Experimenter effects on behavioral test scores of eight inbred mouse strains under the influence of ethanol

PubMed Central

Bohlen, Martin; Hayes, Erika R.; Bohlen, Benjamin; Bailoo, Jeremy; Crabbe, John C.; Wahlsten, Douglas

2016-01-01

Eight standard inbred mouse strains were evaluated for ethanol effects on a refined battery of behavioral tests in a study that was originally designed to assess the influence of rat odors in the colony on mouse behaviors. As part of the design of the study, two experimenters conducted the tests, and the study was carefully balanced so that equal numbers of mice in all groups and times of day were tested by each experimenter. A defect in airflow in the facility compromised the odor manipulation, and in fact the different odor exposure groups did not differ in their behaviors. The two experimenters, however, obtained markedly different results for three of the tests. Certain of the experimenter effects arose from the way they judged behaviors that were not automated and had to be rated by the experimenter, such as slips on the balance beam. Others were not evident prior to ethanol injection but had a major influence after the injection. For several measures, the experimenter effects were notably different for different inbred strains. Methods to evaluate and reduce the impact of experimenter effects in future research are discussed. PMID:24933191

Experimenter effects on behavioral test scores of eight inbred mouse strains under the influence of ethanol.

PubMed

Bohlen, Martin; Hayes, Erika R; Bohlen, Benjamin; Bailoo, Jeremy D; Crabbe, John C; Wahlsten, Douglas

2014-10-01

Eight standard inbred mouse strains were evaluated for ethanol effects on a refined battery of behavioral tests in a study that was originally designed to assess the influence of rat odors in the colony on mouse behaviors. As part of the design of the study, two experimenters conducted the tests, and the study was carefully balanced so that equal numbers of mice in all groups and times of day were tested by each experimenter. A defect in airflow in the facility compromised the odor manipulation, and in fact the different odor exposure groups did not differ in their behaviors. The two experimenters, however, obtained markedly different results for three of the tests. Certain of the experimenter effects arose from the way they judged behaviors that were not automated and had to be rated by the experimenter, such as slips on the balance beam. Others were not evident prior to ethanol injection but had a major influence after the injection. For several measures, the experimenter effects were notably different for different inbred strains. Methods to evaluate and reduce the impact of experimenter effects in future research are discussed. Copyright © 2014 Elsevier B.V. All rights reserved.

Near-optimal experimental design for model selection in systems biology.

PubMed

Busetto, Alberto Giovanni; Hauser, Alain; Krummenacher, Gabriel; Sunnåker, Mikael; Dimopoulos, Sotiris; Ong, Cheng Soon; Stelling, Jörg; Buhmann, Joachim M

2013-10-15

Biological systems are understood through iterations of modeling and experimentation. Not all experiments, however, are equally valuable for predictive modeling. This study introduces an efficient method for experimental design aimed at selecting dynamical models from data. Motivated by biological applications, the method enables the design of crucial experiments: it determines a highly informative selection of measurement readouts and time points. We demonstrate formal guarantees of design efficiency on the basis of previous results. By reducing our task to the setting of graphical models, we prove that the method finds a near-optimal design selection with a polynomial number of evaluations. Moreover, the method exhibits the best polynomial-complexity constant approximation factor, unless P = NP. We measure the performance of the method in comparison with established alternatives, such as ensemble non-centrality, on example models of different complexity. Efficient design accelerates the loop between modeling and experimentation: it enables the inference of complex mechanisms, such as those controlling central metabolic operation. Toolbox 'NearOED' available with source code under GPL on the Machine Learning Open Source Software Web site (mloss.org).

Toward New Magnesium Alloy Design - Theoretical and Experimental Studies of the Influence of Alloying Elements on Deformation Twinning

DTIC Science & Technology

2013-03-27

Research Office (W911NF-12-1-0023). Ab initio calculations have been performed to study the effects of solute atoms on the c/a ratio of magnesium alloys ... effects of alloying elements on the c/a ratio of magnesium were performed. The most commonly and extensively used alloying elements such as Al, Mn, and... Magnesium Alloy Design - Theoretical and Experimental Studies of the Influence of Alloying Elements on Deformation Twinning M.F. Horstemeyer

Invited review: study design considerations for clinical research in veterinary radiology and radiation oncology.

PubMed

Scrivani, Peter V; Erb, Hollis N

2013-01-01

High quality clinical research is essential for advancing knowledge in the areas of veterinary radiology and radiation oncology. Types of clinical research studies may include experimental studies, method-comparison studies, and patient-based studies. Experimental studies explore issues relative to pathophysiology, patient safety, and treatment efficacy. Method-comparison studies evaluate agreement between techniques or between observers. Patient-based studies investigate naturally acquired disease and focus on questions asked in clinical practice that relate to individuals or populations (e.g., risk, accuracy, or prognosis). Careful preplanning and study design are essential in order to achieve valid results. A key point to planning studies is ensuring that the design is tailored to the study objectives. Good design includes a comprehensive literature review, asking suitable questions, selecting the proper sample population, collecting the appropriate data, performing the correct statistical analyses, and drawing conclusions supported by the available evidence. Most study designs are classified by whether they are experimental or observational, longitudinal or cross-sectional, and prospective or retrospective. Additional features (e.g., controlled, randomized, or blinded) may be described that address bias. Two related challenging aspects of study design are defining an important research question and selecting an appropriate sample population. The sample population should represent the target population as much as possible. Furthermore, when comparing groups, it is important that the groups are as alike to each other as possible except for the variables of interest. Medical images are well suited for clinical research because imaging signs are categorical or numerical variables that might be predictors or outcomes of diseases or treatments. © 2013 Veterinary Radiology & Ultrasound.

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

Heaney, Mike

Statistically designed experiments can save researchers time and money by reducing the number of necessary experimental trials, while resulting in more conclusive experimental results. Surprisingly, many researchers are still not aware of this efficient and effective experimental methodology. As reported in a 2013 article from Chemical & Engineering News, there has been a resurgence of this methodology in recent years (http://cen.acs.org/articles/91/i13/Design-Experiments-Makes-Comeback.html?h=2027056365). This presentation will provide a brief introduction to statistically designed experiments. The main advantages will be reviewed along with the some basic concepts such as factorial and fractional factorial designs. The recommended sequential approach to experiments will be introducedmore » and finally a case study will be presented to demonstrate this methodology.« less

Optimization of large animal MI models; a systematic analysis of control groups from preclinical studies.

PubMed

Zwetsloot, P P; Kouwenberg, L H J A; Sena, E S; Eding, J E; den Ruijter, H M; Sluijter, J P G; Pasterkamp, G; Doevendans, P A; Hoefer, I E; Chamuleau, S A J; van Hout, G P J; Jansen Of Lorkeers, S J

2017-10-27

Large animal models are essential for the development of novel therapeutics for myocardial infarction. To optimize translation, we need to assess the effect of experimental design on disease outcome and model experimental design to resemble the clinical course of MI. The aim of this study is therefore to systematically investigate how experimental decisions affect outcome measurements in large animal MI models. We used control animal-data from two independent meta-analyses of large animal MI models. All variables of interest were pre-defined. We performed univariable and multivariable meta-regression to analyze whether these variables influenced infarct size and ejection fraction. Our analyses incorporated 246 relevant studies. Multivariable meta-regression revealed that infarct size and cardiac function were influenced independently by choice of species, sex, co-medication, occlusion type, occluded vessel, quantification method, ischemia duration and follow-up duration. We provide strong systematic evidence that commonly used endpoints significantly depend on study design and biological variation. This makes direct comparison of different study-results difficult and calls for standardized models. Researchers should take this into account when designing large animal studies to most closely mimic the clinical course of MI and enable translational success.

Assessing the applicability of the Taguchi design method to an interrill erosion study

NASA Astrophysics Data System (ADS)

Zhang, F. B.; Wang, Z. L.; Yang, M. Y.

2015-02-01

Full-factorial experimental designs have been used in soil erosion studies, but are time, cost and labor intensive, and sometimes they are impossible to conduct due to the increasing number of factors and their levels to consider. The Taguchi design is a simple, economical and efficient statistical tool that only uses a portion of the total possible factorial combinations to obtain the results of a study. Soil erosion studies that use the Taguchi design are scarce and no comparisons with full-factorial designs have been made. In this paper, a series of simulated rainfall experiments using a full-factorial design of five slope lengths (0.4, 0.8, 1.2, 1.6, and 2 m), five slope gradients (18%, 27%, 36%, 48%, and 58%), and five rainfall intensities (48, 62.4, 102, 149, and 170 mm h-1) were conducted. Validation of the applicability of a Taguchi design to interrill erosion experiments was achieved by extracting data from the full dataset according to a theoretical Taguchi design. The statistical parameters for the mean quasi-steady state erosion and runoff rates of each test, the optimum conditions for producing maximum erosion and runoff, and the main effect and percentage contribution of each factor obtained from the full-factorial and Taguchi designs were compared. Both designs generated almost identical results. Using the experimental data from the Taguchi design, it was possible to accurately predict the erosion and runoff rates under the conditions that had been excluded from the Taguchi design. All of the results obtained from analyzing the experimental data for both designs indicated that the Taguchi design could be applied to interrill erosion studies and could replace full-factorial designs. This would save time, labor and costs by generally reducing the number of tests to be conducted. Further work should test the applicability of the Taguchi design to a wider range of conditions.

The Impact of Inquiry Based Instruction on Science Process Skills and Self-Efficacy Perceptions of Pre-Service Science Teachers at a University Level Biology Laboratory

ERIC Educational Resources Information Center

Sen, Ceylan; Sezen Vekli, Gülsah

2016-01-01

The aim of this study is to determine the influence of inquiry-based teaching approach on pre-service science teachers' laboratory self-efficacy perceptions and scientific process skills. The quasi experimental model with pre-test-post-test control group design was used as an experimental design in this research. The sample of this study included…

Design, Construction and Testing of Annular Diffusers for High Speed Civil Transportation Combustor Applications

NASA Technical Reports Server (NTRS)

Okhio, Cyril B.

1996-01-01

A theoretical and an experimental design study of subsonic flow through curved-wall annular diffusers has been initiated under this award in order to establish the most pertinent design parameters and hence performance characteristics for such devices, an the implications of their application in the design of engine components in the aerospace industries. The diffusers under this study are expected to contain appreciable regions of stall and the effects of swirl on their performance are being studied. The experimental work involves the application of Computer Aided Design software tool to the development of a suitable annular diffuse geometry and the subsequent downloading of such data to a CNC machine at Central State University (CSU). Two experimental run segments have been completed so far during FY-95 involving flow visualization and diffuser performance evaluation based on Kinetic Energy Dissipation. The method of calculation of the performance of diffusers based on pressure recovery coefficient has been shown to have some shortcomings and so the kinetic energy dissipation approach has been introduced in the run segment two with some success. The application of the discretized, full Navier Stokes and Continuity equations to the numerical study of the problem described above for the time-mean flow is expected to follow. Various models of turbulence are being evaluated for adoption throughout the study and comparisons would be made with experimental data where they exist. Assessment of diffuser performance based on the dissipated mechanical energy would also be made. The result of the investigations are expected to indicate that more cost effective component design of such devices as diffusers which normally contain complex flows can still be achieved.

Optimizing an experimental design for an electromagnetic experiment

NASA Astrophysics Data System (ADS)

Roux, Estelle; Garcia, Xavier

2013-04-01

Most of geophysical studies focus on data acquisition and analysis, but another aspect which is gaining importance is the discussion on acquisition of suitable datasets. This can be done through the design of an optimal experiment. Optimizing an experimental design implies a compromise between maximizing the information we get about the target and reducing the cost of the experiment, considering a wide range of constraints (logistical, financial, experimental …). We are currently developing a method to design an optimal controlled-source electromagnetic (CSEM) experiment to detect a potential CO2 reservoir and monitor this reservoir during and after CO2 injection. Our statistical algorithm combines the use of linearized inverse theory (to evaluate the quality of one given design via the objective function) and stochastic optimization methods like genetic algorithm (to examine a wide range of possible surveys). The particularity of our method is that it uses a multi-objective genetic algorithm that searches for designs that fit several objective functions simultaneously. One main advantage of this kind of technique to design an experiment is that it does not require the acquisition of any data and can thus be easily conducted before any geophysical survey. Our new experimental design algorithm has been tested with a realistic one-dimensional resistivity model of the Earth in the region of study (northern Spain CO2 sequestration test site). We show that a small number of well distributed observations have the potential to resolve the target. This simple test also points out the importance of a well chosen objective function. Finally, in the context of CO2 sequestration that motivates this study, we might be interested in maximizing the information we get about the reservoir layer. In that case, we show how the combination of two different objective functions considerably improve its resolution.

An experimental and computational investigation of flow in a radial inlet of an industrial pipeline centrifugal compressor

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

Flathers, M.B.; Bache, G.E.; Rainsberger, R.

1996-04-01

The flow field of a complex three-dimensional radial inlet for an industrial pipeline centrifugal compressor has been experimentally determined on a half-scale model. Based on the experimental results, inlet guide vanes have been designed to correct pressure and swirl angle distribution deficiencies. The unvaned and vaned inlets are analyzed with a commercially available fully three-dimensional viscous Navier-Stokes code. Since experimental results were available prior to the numerical study, the unvaned analysis is considered a postdiction while the vaned analysis is considered a prediction. The computational results of the unvaned inlet have been compared to the previously obtained experimental results. Themore » experimental method utilized for the unvaned inlet is repeated for the vaned inlet and the data have been used to verify the computational results. The paper will discuss experimental, design, and computational procedures, grid generation, boundary conditions, and experimental versus computational methods. Agreement between experimental and computational results is very good, both in prediction and postdiction modes. The results of this investigation indicate that CFD offers a measurable advantage in design, schedule, and cost and can be applied to complex, three-dimensional radial inlets.« less

Plant disease severity assessment - How rater bias, assessment method and experimental design affect hypothesis testing and resource use efficiency

USDA-ARS?s Scientific Manuscript database

The impact of rater bias and assessment method on hypothesis testing was studied for different experimental designs for plant disease assessment using balanced and unbalanced data sets. Data sets with the same number of replicate estimates for each of two treatments are termed ‘balanced’, and those ...

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…

Divergence of Scientific Heuristic Method and Direct Algebraic Instruction

ERIC Educational Resources Information Center

Calucag, Lina S.

2016-01-01

This is an experimental study, made used of the non-randomized experimental and control groups, pretest-posttest designs. The experimental and control groups were two separate intact classes in Algebra. For a period of twelve sessions, the experimental group was subjected to the scientific heuristic method, but the control group instead was given…

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…

Effects of eccentricities and lateral pressure on the design of stiffened compression panels

NASA Technical Reports Server (NTRS)

Giles, G. L.; Anderson, M. S.

1972-01-01

An analysis for determining the effects of eccentricities and lateral pressure on the design of stiffened compression panels is presented. The four types of panel stiffeners considered are integral, zee, integral zee, and integral tee. Mass-strength curves, which give the mass of the panel necessary to carry a specified load, are given along with related design equations needed to calculate the cross-sectional dimensions of the minimum-mass-stiffened panel. The results of the study indicate that the proportions of the panels are geometrically similar to the proportions of panels designed for no eccentricity or lateral pressure, but no cross-sectional dimensions are greater, resulting in significantly increased mass. The analytical minimum-mass designs of zee-stiffened panels are compared with designs from experimentally derived charts. An assumed eccentricity of 0.001 times the length of the panel is used to correlate the analytical and experimental data. Good correlation between the experimentally derived and the analytical curves is obtained for the range of loading where materials yield governs the design. At lower loads the mass given by the analytical curve using this assumed eccentricity is greater than that given by the experimental results.

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

PubMed

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

2018-01-01

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

Application of Taguchi L32 orthogonal array design to optimize copper biosorption by using Spaghnum moss.

PubMed

Ozdemir, Utkan; Ozbay, Bilge; Ozbay, Ismail; Veli, Sevil

2014-09-01

In this work, Taguchi L32 experimental design was applied to optimize biosorption of Cu(2+) ions by an easily available biosorbent, Spaghnum moss. With this aim, batch biosorption tests were performed to achieve targeted experimental design with five factors (concentration, pH, biosorbent dosage, temperature and agitation time) at two different levels. Optimal experimental conditions were determined by calculated signal-to-noise ratios. "Higher is better" approach was followed to calculate signal-to-noise ratios as it was aimed to obtain high metal removal efficiencies. The impact ratios of factors were determined by the model. Within the study, Cu(2+) biosorption efficiencies were also predicted by using Taguchi method. Results of the model showed that experimental and predicted values were close to each other demonstrating the success of Taguchi approach. Furthermore, thermodynamic, isotherm and kinetic studies were performed to explain the biosorption mechanism. Calculated thermodynamic parameters were in good accordance with the results of Taguchi model. Copyright © 2014 Elsevier Inc. All rights reserved.

Selecting the best design for nonstandard toxicology experiments.

PubMed

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

2014-10-01

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

Evaluation of high temperature superconductive thermal bridges for space-borne cryogenic infrared detectors

NASA Technical Reports Server (NTRS)

Scott, Elaine P.

1993-01-01

The focus of this research is on the reduction of the refrigeration requirements for infrared sensors operating in space through the use of high temperature superconductive (HTS) materials as electronic leads between the cooled sensors and the relatively warmer data acquisition components. Specifically, this initial study was directed towards the design of an experiment to quantify the thermal performance of these materials in the space environment. First, an intensive review of relevant literature was undertaken, and then, design requirements were formulated. From this background information, a preliminary experimental design was developed. Additional studies will involve a thermal analysis of the experiment and further modifications of the experimental design.

Minimizing student’s faults in determining the design of experiment through inquiry-based learning

NASA Astrophysics Data System (ADS)

Nilakusmawati, D. P. E.; Susilawati, M.

2017-10-01

The purpose of this study were to describe the used of inquiry method in an effort to minimize student’s fault in designing an experiment and to determine the effectiveness of the implementation of the inquiry method in minimizing student’s faults in designing experiments on subjects experimental design. This type of research is action research participants, with a model of action research design. The data source were students of the fifth semester who took a subject of experimental design at Mathematics Department, Faculty of Mathematics and Natural Sciences, Udayana University. Data was collected through tests, interviews, and observations. The hypothesis was tested by t-test. The result showed that the implementation of inquiry methods to minimize of students fault in designing experiments, analyzing experimental data, and interpret them in cycle 1 students can reduce fault by an average of 10.5%. While implementation in Cycle 2, students managed to reduce fault by an average of 8.78%. Based on t-test results can be concluded that the inquiry method effectively used to minimize of student’s fault in designing experiments, analyzing experimental data, and interpreting them. The nature of the teaching materials on subject of Experimental Design that demand the ability of students to think in a systematic, logical, and critical in analyzing the data and interpret the test cases makes the implementation of this inquiry become the proper method. In addition, utilization learning tool, in this case the teaching materials and the students worksheet is one of the factors that makes this inquiry method effectively minimizes of student’s fault when designing experiments.

76 FR 25674 - Notice of Submission for OMB Review

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-05

... for the rigorous comparative interrupted time series design including student records data collection...- experimental designs to explore the relationship between magnet programs and student achievement both for... this study. An OMB clearance request that (1) described the study design and full data collection...

78 FR 25710 - Applications for New Awards; Strengthening Institutions Program (SIP)

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-02

... priority in this notice: Carefully matched comparison group design means a type of quasi- experimental... notice). More specifically, it is a design in which project participants are matched with non... group study. When designing their study, applicants should consider participant characteristics relevant...

A Modified Experimental Hut Design for Studying Responses of Disease-Transmitting Mosquitoes to Indoor Interventions: The Ifakara Experimental Huts

PubMed Central

Okumu, Fredros O.; Moore, Jason; Mbeyela, Edgar; Sherlock, Mark; Sangusangu, Robert; Ligamba, Godfrey; Russell, Tanya; Moore, Sarah J.

2012-01-01

Differences between individual human houses can confound results of studies aimed at evaluating indoor vector control interventions such as insecticide treated nets (ITNs) and indoor residual insecticide spraying (IRS). Specially designed and standardised experimental huts have historically provided a solution to this challenge, with an added advantage that they can be fitted with special interception traps to sample entering or exiting mosquitoes. However, many of these experimental hut designs have a number of limitations, for example: 1) inability to sample mosquitoes on all sides of huts, 2) increased likelihood of live mosquitoes flying out of the huts, leaving mainly dead ones, 3) difficulties of cleaning the huts when a new insecticide is to be tested, and 4) the generally small size of the experimental huts, which can misrepresent actual local house sizes or airflow dynamics in the local houses. Here, we describe a modified experimental hut design - The Ifakara Experimental Huts- and explain how these huts can be used to more realistically monitor behavioural and physiological responses of wild, free-flying disease-transmitting mosquitoes, including the African malaria vectors of the species complexes Anopheles gambiae and Anopheles funestus, to indoor vector control-technologies including ITNs and IRS. Important characteristics of the Ifakara experimental huts include: 1) interception traps fitted onto eave spaces and windows, 2) use of eave baffles (panels that direct mosquito movement) to control exit of live mosquitoes through the eave spaces, 3) use of replaceable wall panels and ceilings, which allow safe insecticide disposal and reuse of the huts to test different insecticides in successive periods, 4) the kit format of the huts allowing portability and 5) an improved suite of entomological procedures to maximise data quality. PMID:22347415

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…

A critical evaluation of the experimental design of studies of mechanism based enzyme inhibition, with implications for in vitro-in vivo extrapolation.

PubMed

Ghanbari, F; Rowland-Yeo, K; Bloomer, J C; Clarke, S E; Lennard, M S; Tucker, G T; Rostami-Hodjegan, A

2006-04-01

The published literature on mechanism based inhibition (MBI) of CYPs was evaluated with respect to experimental design, methodology and data analysis. Significant variation was apparent in the dilution factor, ratio of preincubation to incubation times and probe substrate concentrations used, and there were some anomalies in the estimation of associated kinetic parameters (k(inact), K(I), r). The impact of the application of inaccurate values of k(inact) and K(I) when extrapolating to the extent of inhibition in vivo is likely to be greatest for those compounds of intermediate inhibitory potency, but this also depends on the fraction of the net clearance of substrate subject to MBI and the pre-systemic and systemic exposure to the inhibitor. For potent inhibitors, the experimental procedure is unlikely to have a material influence on the maximum inhibition. Nevertheless, the bias in the values of the kinetic parameters may influence the time for recovery of enzyme activity following re-synthesis of the enzyme. Careful attention to the design of in vitro experiments to obtain accurate kinetic parameters is necessary for a reliable prediction of different aspects of the in vivo consequences of MBI. The review calls for experimental studies to quantify the impact of study design in studies of MBI, with a view to better harmonisation of protocols.

Using R in experimental design with BIBD: An application in health sciences

NASA Astrophysics Data System (ADS)

Oliveira, Teresa A.; Francisco, Carla; Oliveira, Amílcar; Ferreira, Agostinho

2016-06-01

Considering the implementation of an Experimental Design, in any field, the experimenter must pay particular attention and look for the best strategies in the following steps: planning the design selection, conduct the experiments, collect observed data, proceed to analysis and interpretation of results. The focus is on providing both - a deep understanding of the problem under research and a powerful experimental process at a reduced cost. Mainly thanks to the possibility of allowing to separate variation sources, the importance of Experimental Design in Health Sciences is strongly recommended since long time. Particular attention has been devoted to Block Designs and more precisely to Balanced Incomplete Block Designs - in this case the relevance states from the fact that these designs allow testing simultaneously a number of treatments bigger than the block size. Our example refers to a possible study of inter reliability of the Parkinson disease, taking into account the UPDRS (Unified Parkinson's disease rating scale) in order to test if there are significant differences between the specialists who evaluate the patients performances. Statistical studies on this disease were described for example in Richards et al (1994), where the authors investigate the inter-rater Reliability of the Unified Parkinson's Disease Rating Scale Motor Examination. We consider a simulation of a practical situation in which the patients were observed by different specialists and the UPDRS on assessing the impact of Parkinson's disease in patients was observed. Assigning treatments to the subjects following a particular BIBD(9,24,8,3,2) structure, we illustrate that BIB Designs can be used as a powerful tool to solve emerging problems in this area. Once a structure with repeated blocks allows to have some block contrasts with minimum variance, see Oliveira et al. (2006), the design with cardinality 12 was selected for the example. R software was used for computations.

High-Impact Aerobic and Zumba Fitness on Increasing VO2MAX, Heart Rate Recovery and Skinfold Thickness

NASA Astrophysics Data System (ADS)

Suminar, T. J.; Kusnanik, N. W.; Wiriawan, O.

2018-01-01

Purpose of this study is to determine the significant effect of high-impact aerobics exercise, and Zumba fitness on increasing VO2Max, decreasing of heart rate recovery, and decreasing of skinfold thickness. A sample of this study is 30 members aerobics of student activity unit. Type of this study was quantitative by using a quasi-experimental design method. The design of this study used Matching-Only Design. Data were Analyzed by using the t test (paired t-test). The samples divided into three groups consisted of experimental group I, experimental group II, and control group. They were given a treatment for 8 weeks or 24 meeting. For the data, retrieval is done by MFT test, heart rate recovery test, and skinfold thickness test. Furthermore, the result was analyzed by using SPSS 21 series. In conclusion, significant effect of high-impact aerobics and Zumba fitness on increasing VO2Max, heart rate recovery, skinfold thickness.

Systematic survey of the design, statistical analysis, and reporting of studies published in the 2008 volume of the Journal of Cerebral Blood Flow and Metabolism.

PubMed

Vesterinen, Hanna M; Vesterinen, Hanna V; Egan, Kieren; Deister, Amelie; Schlattmann, Peter; Macleod, Malcolm R; Dirnagl, Ulrich

2011-04-01

Translating experimental findings into clinically effective therapies is one of the major bottlenecks of modern medicine. As this has been particularly true for cerebrovascular research, attention has turned to the quality and validity of experimental cerebrovascular studies. We set out to assess the study design, statistical analyses, and reporting of cerebrovascular research. We assessed all original articles published in the Journal of Cerebral Blood Flow and Metabolism during the year 2008 against a checklist designed to capture the key attributes relating to study design, statistical analyses, and reporting. A total of 156 original publications were included (animal, in vitro, human). Few studies reported a primary research hypothesis, statement of purpose, or measures to safeguard internal validity (such as randomization, blinding, exclusion or inclusion criteria). Many studies lacked sufficient information regarding methods and results to form a reasonable judgment about their validity. In nearly 20% of studies, statistical tests were either not appropriate or information to allow assessment of appropriateness was lacking. This study identifies a number of factors that should be addressed if the quality of research in basic and translational biomedicine is to be improved. We support the widespread implementation of the ARRIVE (Animal Research Reporting In Vivo Experiments) statement for the reporting of experimental studies in biomedicine, for improving training in proper study design and analysis, and that reviewers and editors adopt a more constructively critical approach in the assessment of manuscripts for publication.

Systematic survey of the design, statistical analysis, and reporting of studies published in the 2008 volume of the Journal of Cerebral Blood Flow and Metabolism

PubMed Central

Vesterinen, Hanna V; Egan, Kieren; Deister, Amelie; Schlattmann, Peter; Macleod, Malcolm R; Dirnagl, Ulrich

2011-01-01

Translating experimental findings into clinically effective therapies is one of the major bottlenecks of modern medicine. As this has been particularly true for cerebrovascular research, attention has turned to the quality and validity of experimental cerebrovascular studies. We set out to assess the study design, statistical analyses, and reporting of cerebrovascular research. We assessed all original articles published in the Journal of Cerebral Blood Flow and Metabolism during the year 2008 against a checklist designed to capture the key attributes relating to study design, statistical analyses, and reporting. A total of 156 original publications were included (animal, in vitro, human). Few studies reported a primary research hypothesis, statement of purpose, or measures to safeguard internal validity (such as randomization, blinding, exclusion or inclusion criteria). Many studies lacked sufficient information regarding methods and results to form a reasonable judgment about their validity. In nearly 20% of studies, statistical tests were either not appropriate or information to allow assessment of appropriateness was lacking. This study identifies a number of factors that should be addressed if the quality of research in basic and translational biomedicine is to be improved. We support the widespread implementation of the ARRIVE (Animal Research Reporting In Vivo Experiments) statement for the reporting of experimental studies in biomedicine, for improving training in proper study design and analysis, and that reviewers and editors adopt a more constructively critical approach in the assessment of manuscripts for publication. PMID:21157472

[Effects of heat therapy using a far infrared rays heating element for dysmenorrhea in high school girls].

PubMed

Hong, Yeon Ran

2011-02-01

The purpose of this study was designed to identify the effects of heat therapy on dysmenorrhea, heat being provided using a far infrared rays heating element. The research design for the study was a non-equivalent control group quasi-experimental design. Participants were 22 students for the experimental group, and 26 students for the control group. Data were analyzed using SAS WIN 9.1 program. The experimental group had significantly lower mean scores for menstrual pain, dysmenorrhea, and blood pressure than those in the control group. However, no significant differences were found between two groups for pulse, respiration, and temperature. These findings show that thermotherapy was effective for reduction of menstrual pain, dysmenorrhea, and B/P. Therefore, this therapy could be used as a nursing intervention for students with dysmenorrhea.

Experimental Lithium-Ion Battery Developed for Demonstration at the 2007 NASA Desert Research and Technology Studies (D-RATS) Program

NASA Technical Reports Server (NTRS)

Bennett, William R.; Baldwin, Richard S.

2010-01-01

The NASA Glenn Research Center (GRC) Electrochemistry Branch designed and built five lithium-ion battery packs for demonstration in spacesuit simulators as a part of the 2007 Desert Research and Technology Studies (D-RATS) activity at Cinder Lake, Arizona. The experimental batteries incorporated advanced, NASA-developed electrolytes and included internal protection against over-current, overdischarge and over-temperature. The 500-g experimental batteries were designed to deliver a constant power of 22 W for 2.5 hr with a minimum voltage of 13 V. When discharged at the maximum expected power output of 38.5 W, the batteries operated for 103 min of discharge time, achieving a specific energy of 130 Wh/kg. This report summarizes design details and safety considerations. Results for field trials and laboratory testing are summarized.

Effectiveness of Facebook Based Learning to Enhance Creativity among Islamic Studies Students by Employing Isman Instructional Design Model

ERIC Educational Resources Information Center

Alias, Norlidah; Siraj, Saedah; Daud, Mohd Khairul Azman Md; Hussin, Zaharah

2013-01-01

The study examines the effectiveness of Facebook based learning to enhance creativity among Islamic Studies students in the secondary educational setting in Malaysia. It describes the design process by employing the Isman Instructional Design Model. A quantitative study was carried out using experimental method and background survey. The…

Analysis of pre-service physics teacher skills designing simple physics experiments based technology

NASA Astrophysics Data System (ADS)

Susilawati; Huda, C.; Kurniawan, W.; Masturi; Khoiri, N.

2018-03-01

Pre-service physics teacher skill in designing simple experiment set is very important in adding understanding of student concept and practicing scientific skill in laboratory. This study describes the skills of physics students in designing simple experiments based technologicall. The experimental design stages include simple tool design and sensor modification. The research method used is descriptive method with the number of research samples 25 students and 5 variations of simple physics experimental design. Based on the results of interviews and observations obtained the results of pre-service physics teacher skill analysis in designing simple experimental physics charged technology is good. Based on observation result, pre-service physics teacher skill in designing simple experiment is good while modification and sensor application are still not good. This suggests that pre-service physics teacher still need a lot of practice and do experiments in designing physics experiments using sensor modifications. Based on the interview result, it is found that students have high enough motivation to perform laboratory activities actively and students have high curiosity to be skilled at making simple practicum tool for physics experiment.

Use of experimental design in the investigation of stir bar sorptive extraction followed by ultra-high-performance liquid chromatography-tandem mass spectrometry for the analysis of explosives in water samples.

PubMed

Schramm, Sébastien; Vailhen, Dominique; Bridoux, Maxime Cyril

2016-02-12

A method for the sensitive quantification of trace amounts of organic explosives in water samples was developed by using stir bar sorptive extraction (SBSE) followed by liquid desorption and ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). The proposed method was developed and optimized using a statistical design of experiment approach. Use of experimental designs allowed a complete study of 10 factors and 8 analytes including nitro-aromatics, amino-nitro-aromatics and nitric esters. The liquid desorption study was performed using a full factorial experimental design followed by a kinetic study. Four different variables were tested here: the liquid desorption mode (stirring or sonication), the chemical nature of the stir bar (PDMS or PDMS-PEG), the composition of the liquid desorption phase and finally, the volume of solvent used for the liquid desorption. On the other hand, the SBSE extraction study was performed using a Doehlert design. SBSE extraction conditions such as extraction time profiles, sample volume, modifier addition, and acetic acid addition were examined. After optimization of the experimental parameters, sensitivity was improved by a factor 5-30, depending on the compound studied, due to the enrichment factors reached using the SBSE method. Limits of detection were in the ng/L level for all analytes studied. Reproducibility of the extraction with different stir bars was close to the reproducibility of the analytical method (RSD between 4 and 16%). Extractions in various water sample matrices (spring, mineral and underground water) have shown similar enrichment compared to ultrapure water, revealing very low matrix effects. Copyright © 2016 Elsevier B.V. All rights reserved.

A Simulation Study on the Performance of the Simple Difference and Covariance-Adjusted Scores in Randomized Experimental Designs

ERIC Educational Resources Information Center

Petscher, Yaacov; Schatschneider, Christopher

2011-01-01

Research by Huck and McLean (1975) demonstrated that the covariance-adjusted score is more powerful than the simple difference score, yet recent reviews indicate researchers are equally likely to use either score type in two-wave randomized experimental designs. A Monte Carlo simulation was conducted to examine the conditions under which the…

Effects of experimental design and protein substitution strategy on production responses to feeding different levels of protein to primiparous dairy cows

USDA-ARS?s Scientific Manuscript database

Inferences about lactation responses to diet have been hypothesized to be affected by the use of change-over instead of continuous experimental designs. A direct test of this hypothesis has not been well studied. Additionally, when dietary protein level is changed it must occur through dilution with...

TummyTrials: A Feasibility Study of Using Self-Experimentation to Detect Individualized Food Triggers.

PubMed

Karkar, Ravi; Schroeder, Jessica; Epstein, Daniel A; Pina, Laura R; Scofield, Jeffrey; Fogarty, James; Kientz, Julie A; Munson, Sean A; Vilardaga, Roger; Zia, Jasmine

2017-05-02

Diagnostic self-tracking, the recording of personal information to diagnose or manage a health condition, is a common practice, especially for people with chronic conditions. Unfortunately, many who attempt diagnostic self-tracking have trouble accomplishing their goals. People often lack knowledge and skills needed to design and conduct scientifically rigorous experiments, and current tools provide little support. To address these shortcomings and explore opportunities for diagnostic self-tracking, we designed, developed, and evaluated a mobile app that applies a self-experimentation framework to support patients suffering from irritable bowel syndrome (IBS) in identifying their personal food triggers. TummyTrials aids a person in designing, executing, and analyzing self-experiments to evaluate whether a specific food triggers their symptoms. We examined the feasibility of this approach in a field study with 15 IBS patients, finding that participants could use the tool to reliably undergo a self-experiment. However, we also discovered an underlying tension between scientific validity and the lived experience of self-experimentation. We discuss challenges of applying clinical research methods in everyday life, motivating a need for the design of self-experimentation systems to balance rigor with the uncertainties of everyday life.

Code Validation Studies of High-Enthalpy Flows

DTIC Science & Technology

2006-12-01

stage of future hypersonic vehicles. The development and design of such vehicles is aided by the use of experimentation and numerical simulation... numerical predictions and experimental measurements. 3. Summary of Previous Work We have studied extensively hypersonic double-cone flows with and in...the experimental measurements and the numerical predictions. When we accounted for that effect in numerical simulations, and also augmented the

Data Analysis Strategies for Quasi-Experimental Studies Where Differential Group and Individual Growth Rates Are Assumed. Research Series No. 13.

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…

Comparison between project-based learning and discovery learning toward students' metacognitive strategies on global warming concept

NASA Astrophysics Data System (ADS)

Tumewu, Widya Anjelia; Wulan, Ana Ratna; Sanjaya, Yayan

2017-05-01

The purpose of this study was to know comparing the effectiveness of learning using Project-based learning (PjBL) and Discovery Learning (DL) toward students metacognitive strategies on global warming concept. A quasi-experimental research design with a The Matching-Only Pretest-Posttest Control Group Design was used in this study. The subjects were students of two classes 7th grade of one of junior high school in Bandung City, West Java of 2015/2016 academic year. The study was conducted on two experimental class, that were project-based learning treatment on the experimental class I and discovery learning treatment was done on the experimental class II. The data was collected through questionnaire to know students metacognitive strategies. The statistical analysis showed that there were statistically significant differences in students metacognitive strategies between project-based learning and discovery learning.

Experimental pretesting of public health campaigns: a case study.

PubMed

Whittingham, Jill; Ruiter, Robert A C; Zimbile, Filippo; Kok, Gerjo

2008-01-01

The aim of the present study is to demonstrate the merits of evaluating new public health campaign materials in the developmental phase using an experimental design. This is referred to as experimental pretesting. In practice, most new materials are tested only after they have been distributed using nonexperimental or quasiexperimental designs. In cases where materials are pretested prior to distribution, pretesting is usually done using qualitative research methods such as focus groups. Although these methods are useful, they cannot reliably predict the effectiveness of new campaign materials in a developmental phase. Therefore, we suggest when pretesting new materials, not only qualitative research methods but also experimental research methods must be used. The present study discusses an experimental pretest study of new campaign materials intended for distribution in a national sexually transmitted infection (STI) AIDS prevention campaign in the Netherlands. The campaign material tested was the storyline of a planned television commercial on safe sex. A storyboard that consisted of drawings and text was presented to members of the target population, namely, students between the ages of 14 and 16 enrolled in vocational schools. Results showed positive effects on targeted determinants of safe sexual behavior. The advantages, practical implications, and limitations of experimental pretesting are discussed.

40 CFR 792.120 - Protocol.

Code of Federal Regulations, 2014 CFR

2014-07-01

... the test system. (8) A description of the experimental design, including methods for the control of... at which the study is being conducted. (4) The proposed experimental start and termination dates. (5...

40 CFR 792.120 - Protocol.

Code of Federal Regulations, 2012 CFR

2012-07-01

... the test system. (8) A description of the experimental design, including methods for the control of... at which the study is being conducted. (4) The proposed experimental start and termination dates. (5...

40 CFR 792.120 - Protocol.

Code of Federal Regulations, 2013 CFR

2013-07-01

... the test system. (8) A description of the experimental design, including methods for the control of... at which the study is being conducted. (4) The proposed experimental start and termination dates. (5...

40 CFR 792.120 - Protocol.

Code of Federal Regulations, 2011 CFR

2011-07-01

... the test system. (8) A description of the experimental design, including methods for the control of... at which the study is being conducted. (4) The proposed experimental start and termination dates. (5...

Sampling flies or sampling flaws? Experimental design and inference strength in forensic entomology.

PubMed

Michaud, J-P; Schoenly, Kenneth G; Moreau, G

2012-01-01

Forensic entomology is an inferential science because postmortem interval estimates are based on the extrapolation of results obtained in field or laboratory settings. Although enormous gains in scientific understanding and methodological practice have been made in forensic entomology over the last few decades, a majority of the field studies we reviewed do not meet the standards for inference, which are 1) adequate replication, 2) independence of experimental units, and 3) experimental conditions that capture a representative range of natural variability. Using a mock case-study approach, we identify design flaws in field and lab experiments and suggest methodological solutions for increasing inference strength that can inform future casework. Suggestions for improving data reporting in future field studies are also proposed.

Measurement Techniques for Respiratory Tract Deposition of Airborne Nanoparticles: A Critical Review

PubMed Central

Möller, Winfried; Pagels, Joakim H.; Kreyling, Wolfgang G.; Swietlicki, Erik; Schmid, Otmar

2014-01-01

Abstract Determination of the respiratory tract deposition of airborne particles is critical for risk assessment of air pollution, inhaled drug delivery, and understanding of respiratory disease. With the advent of nanotechnology, there has been an increasing interest in the measurement of pulmonary deposition of nanoparticles because of their unique properties in inhalation toxicology and medicine. Over the last century, around 50 studies have presented experimental data on lung deposition of nanoparticles (typical diameter≤100 nm, but here≤300 nm). These data show a considerable variability, partly due to differences in the applied methodologies. In this study, we review the experimental techniques for measuring respiratory tract deposition of nano-sized particles, analyze critical experimental design aspects causing measurement uncertainties, and suggest methodologies for future studies. It is shown that, although particle detection techniques have developed with time, the overall methodology in respiratory tract deposition experiments has not seen similar progress. Available experience from previous research has often not been incorporated, and some methodological design aspects that were overlooked in 30–70% of all studies may have biased the experimental data. This has contributed to a significant uncertainty on the absolute value of the lung deposition fraction of nanoparticles. We estimate the impact of the design aspects on obtained data, discuss solutions to minimize errors, and highlight gaps in the available experimental set of data. PMID:24151837

Quasi-experimental study designs series-paper 11: supporting the production and use of health systems research syntheses that draw on quasi-experimental study designs.

PubMed

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.

Considerations for the design and execution of protocols for animal research and treatment to improve reproducibility and standardization: "DEPART well-prepared and ARRIVE safely".

PubMed

Smith, M M; Clarke, E C; Little, C B

2017-03-01

To review the factors in experimental design that contribute to poor translation of pre-clinical research to therapies for patients with osteoarthritis (OA) and how this might be improved. Narrative review of the literature, and evaluation of the different stages of design conduct and analysis of studies using animal models of OA to define specific issues that might reduce quality of evidence and how this can be minimised. Preventing bias and improving experimental rigour and reporting are important modifiable factors to improve translation from pre-clinical animal models to successful clinical trials of therapeutic agents. Despite publication and adoption by many journals of guidelines such as Animals in Research: Reporting In Vivo Experiments (ARRIVE), experimental animal studies published in leading rheumatology journals are still deficient in their reporting. In part, this may be caused by researchers first consulting these guidelines after the completion of experiments, at the time of publication. This review discusses factors that can (1) bias the outcome of experimental studies using animal models of osteoarthritis or (2) alter the quality of evidence for translation. We propose a checklist to consult prior to starting experiments; in the Design and Execution of Protocols for Animal Research and Treatment (DEPART). Following DEPART during the design phase will enable completion of the ARRIVE checklist at the time of publication, and thus improve the quality of evidence for inclusion of experimental animal research in meta-analyses and systematic reviews: "DEPART well-prepared and ARRIVE safely". Copyright © 2016 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

Systematic review of control groups in nutrition education intervention research.

PubMed

Byrd-Bredbenner, Carol; Wu, FanFan; Spaccarotella, Kim; Quick, Virginia; Martin-Biggers, Jennifer; Zhang, Yingting

2017-07-11

Well-designed research trials are critical for determining the efficacy and effectiveness of nutrition education interventions. To determine whether behavioral and/or cognition changes can be attributed to an intervention, the experimental design must include a control or comparison condition against which outcomes from the experimental group can be compared. Despite the impact different types of control groups can have on study outcomes, the treatment provided to participants in the control condition has received limited attention in the literature. A systematic review of control groups in nutrition education interventions was conducted to better understand how control conditions are described in peer-reviewed journal articles compared with experimental conditions. To be included in the systematic review, articles had to be indexed in CINAHL, PubMed, PsycINFO, WoS, and/or ERIC and report primary research findings of controlled nutrition education intervention trials conducted in the United States with free-living consumer populations and published in English between January 2005 and December 2015. Key elements extracted during data collection included treatment provided to the experimental and control groups (e.g., overall intervention content, tailoring methods, delivery mode, format, duration, setting, and session descriptions, and procedures for standardizing, fidelity of implementation, and blinding); rationale for control group type selected; sample size and attrition; and theoretical foundation. The search yielded 43 publications; about one-third of these had an inactive control condition, which is considered a weak study design. Nearly two-thirds of reviewed studies had an active control condition considered a stronger research design; however, many failed to report one or more key elements of the intervention, especially for the control condition. None of the experimental and control group treatments were sufficiently detailed to permit replication of the nutrition education interventions studied. Findings advocate for improved intervention study design and more complete reporting of nutrition education interventions.

Scaling Studies for Advanced High Temperature Reactor Concepts, Final Technical Report: October 2014—December 2017

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

Woods, Brian; Gutowska, Izabela; Chiger, Howard

Computer simulations of nuclear reactor thermal-hydraulic phenomena are often used in the design and licensing of nuclear reactor systems. In order to assess the accuracy of these computer simulations, computer codes and methods are often validated against experimental data. This experimental data must be of sufficiently high quality in order to conduct a robust validation exercise. In addition, this experimental data is generally collected at experimental facilities that are of a smaller scale than the reactor systems that are being simulated due to cost considerations. Therefore, smaller scale test facilities must be designed and constructed in such a fashion tomore » ensure that the prototypical behavior of a particular nuclear reactor system is preserved. The work completed through this project has resulted in scaling analyses and conceptual design development for a test facility capable of collecting code validation data for the following high temperature gas reactor systems and events— 1. Passive natural circulation core cooling system, 2. pebble bed gas reactor concept, 3. General Atomics Energy Multiplier Module reactor, and 4. prismatic block design steam-water ingress event. In the event that code validation data for these systems or events is needed in the future, significant progress in the design of an appropriate integral-type test facility has already been completed as a result of this project. Where applicable, the next step would be to begin the detailed design development and material procurement. As part of this project applicable scaling analyses were completed and test facility design requirements developed. Conceptual designs were developed for the implementation of these design requirements at the Oregon State University (OSU) High Temperature Test Facility (HTTF). The original HTTF is based on a ¼-scale model of a high temperature gas reactor concept with the capability for both forced and natural circulation flow through a prismatic core with an electrical heat source. The peak core region temperature capability is 1400°C. As part of this project, an inventory of test facilities that could be used for these experimental programs was completed. Several of these facilities showed some promise, however, upon further investigation it became clear that only the OSU HTTF had the power and/or peak temperature limits that would allow for the experimental programs envisioned herein. Thus the conceptual design and feasibility study development focused on examining the feasibility of configuring the current HTTF to collect validation data for these experimental programs. In addition to the scaling analyses and conceptual design development, a test plan was developed for the envisioned modified test facility. This test plan included a discussion on an appropriate shakedown test program as well as the specific matrix tests. Finally, a feasibility study was completed to determine the cost and schedule considerations that would be important to any test program developed to investigate these designs and events.« less

A framework for accelerated phototrophic bioprocess development: integration of parallelized microscale cultivation, laboratory automation and Kriging-assisted experimental design.

PubMed

Morschett, Holger; Freier, Lars; Rohde, Jannis; Wiechert, Wolfgang; von Lieres, Eric; Oldiges, Marco

2017-01-01

Even though microalgae-derived biodiesel has regained interest within the last decade, industrial production is still challenging for economic reasons. Besides reactor design, as well as value chain and strain engineering, laborious and slow early-stage parameter optimization represents a major drawback. The present study introduces a framework for the accelerated development of phototrophic bioprocesses. A state-of-the-art micro-photobioreactor supported by a liquid-handling robot for automated medium preparation and product quantification was used. To take full advantage of the technology's experimental capacity, Kriging-assisted experimental design was integrated to enable highly efficient execution of screening applications. The resulting platform was used for medium optimization of a lipid production process using Chlorella vulgaris toward maximum volumetric productivity. Within only four experimental rounds, lipid production was increased approximately threefold to 212 ± 11 mg L -1  d -1 . Besides nitrogen availability as a key parameter, magnesium, calcium and various trace elements were shown to be of crucial importance. Here, synergistic multi-parameter interactions as revealed by the experimental design introduced significant further optimization potential. The integration of parallelized microscale cultivation, laboratory automation and Kriging-assisted experimental design proved to be a fruitful tool for the accelerated development of phototrophic bioprocesses. By means of the proposed technology, the targeted optimization task was conducted in a very timely and material-efficient manner.

Selection for production-related traits in Pelargonium zonale: improved design and analysis make all the difference

PubMed Central

Molenaar, Heike; Glawe, Martin; Boehm, Robert; Piepho, Hans-Peter

2017-01-01

Ornamental plant variety improvement is limited by current phenotyping approaches and neglected use of experimental designs. The present study was conducted to show the benefits of using an experimental design and corresponding analysis in ornamental breeding regarding simulated response to selection in Pelargonium zonale for production-related traits. This required establishment of phenotyping protocols for root formation and stem cutting counts, with which 974 genotypes were assessed in a two-phase experimental design. The present paper evaluates this protocol. The possibility of varietal improvement through indirect selection on secondary traits such as branch count and flower count was assessed by genetic correlations. Simulated response to selection varied greatly, depending on the genotypic variances of the breeding population and traits. A varietal improvement of over 20% is possible for stem cutting count, root formation, branch count and flower count. In contrast, indirect selection of stem cutting count by branch count or flower count was found to be ineffective. The established phenotypic protocols and two-phase experimental designs are valuable tools for breeding of P. zonale. PMID:28243453

Selection for production-related traits in Pelargonium zonale: improved design and analysis make all the difference.

PubMed

Molenaar, Heike; Glawe, Martin; Boehm, Robert; Piepho, Hans-Peter

2017-01-01

Ornamental plant variety improvement is limited by current phenotyping approaches and neglected use of experimental designs. The present study was conducted to show the benefits of using an experimental design and corresponding analysis in ornamental breeding regarding simulated response to selection in Pelargonium zonale for production-related traits. This required establishment of phenotyping protocols for root formation and stem cutting counts, with which 974 genotypes were assessed in a two-phase experimental design. The present paper evaluates this protocol. The possibility of varietal improvement through indirect selection on secondary traits such as branch count and flower count was assessed by genetic correlations. Simulated response to selection varied greatly, depending on the genotypic variances of the breeding population and traits. A varietal improvement of over 20% is possible for stem cutting count, root formation, branch count and flower count. In contrast, indirect selection of stem cutting count by branch count or flower count was found to be ineffective. The established phenotypic protocols and two-phase experimental designs are valuable tools for breeding of P. zonale .

76 FR 22084 - Notice of Submission for OMB Review

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-20

... examine the feasibility of a promising practices study of Upward Bound that uses a rigorous quasi-experimental design. The design and feasibility report will develop a set of design options for conducting a...

Developing a cost effective rock bed thermal energy storage system: Design and modelling

NASA Astrophysics Data System (ADS)

Laubscher, Hendrik Frederik; von Backström, Theodor Willem; Dinter, Frank

2017-06-01

Thermal energy storage is an integral part of the drive for low cost of concentrated solar power (CSP). Storage of thermal energy enables CSP plants to provide base load power. Alternative, cheaper concepts for storing thermal energy have been conceptually proposed in previous studies. Using rocks as a storage medium and air as a heat transfer fluid, the proposed concept offers the potential of lower cost storage because of the abundance and affordability of rocks. A packed rock bed thermal energy storage (TES) concept is investigated and a design for an experimental rig is done. This paper describes the design and modelling of an experimental test facility for a cost effective packed rock bed thermal energy storage system. Cost effective, simplified designs for the different subsystems of an experimental setup are developed based on the availability of materials and equipment. Modelling of this design to predict the thermal performance of the TES system is covered in this study. If the concept under consideration proves to be successful, a design that is scalable and commercially viable can be proposed for further development of an industrial thermal energy storage system.

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…

Tracer tomography: design concepts and field experiments using heat as a tracer.

PubMed

Doro, Kennedy O; Cirpka, Olaf A; Leven, Carsten

2015-04-01

Numerical and laboratory studies have provided evidence that combining hydraulic tomography with tomographic tracer tests could improve the estimation of hydraulic conductivity compared with using hydraulic data alone. Field demonstrations, however, have been lacking so far, which we attribute to experimental difficulties. In this study, we present a conceptual design and experimental applications of tracer tomography at the field scale using heat as a tracer. In our experimental design, we improve active heat tracer testing by minimizing possible effects of heat losses, buoyancy, viscosity, and changing boundary conditions. We also utilize a cost-effective approach of measuring temperature changes in situ at high resolution. We apply the presented method to the 8 m thick heterogeneous, sandy gravel, alluvial aquifer at the Lauswiesen Hydrogeological Research Site in Tübingen, Germany. Results of our tomographic heat-tracer experiments are in line with earlier work on characterizing the aquifer at the test site. We demonstrate from the experimental perspective that tracer tomography is applicable and suitable at the field scale using heat as a tracer. The experimental results also demonstrate the potential of heat-tracer tomography as a cost-effective means for characterizing aquifer heterogeneity. © 2014, National Ground Water Association.

Optimization of the combined ultrasonic assisted/adsorption method for the removal of malachite green by gold nanoparticles loaded on activated carbon: Experimental design

NASA Astrophysics Data System (ADS)

Roosta, M.; Ghaedi, M.; Shokri, N.; Daneshfar, A.; Sahraei, R.; Asghari, A.

2014-01-01

The present study was aimed to experimental design optimization applied to removal of malachite green (MG) from aqueous solution by ultrasound-assisted removal onto the gold nanoparticles loaded on activated carbon (Au-NP-AC). This nanomaterial was characterized using different techniques such as FESEM, TEM, BET, and UV-vis measurements. The effects of variables such as pH, initial dye concentration, adsorbent dosage (g), temperature and sonication time on MG removal were studied using central composite design (CCD) and the optimum experimental conditions were found with desirability function (DF) combined response surface methodology (RSM). Fitting the experimental equilibrium data to various isotherm models such as Langmuir, Freundlich, Tempkin and Dubinin-Radushkevich models show the suitability and applicability of the Langmuir model. Kinetic models such as pseudo -first order, pseudo-second order, Elovich and intraparticle diffusion models applicability was tested for experimental data and the second-order equation and intraparticle diffusion models control the kinetic of the adsorption process. The small amount of proposed adsorbent (0.015 g) is applicable for successful removal of MG (RE > 99%) in short time (4.4 min) with high adsorption capacity (140-172 mg g-1).

Deciphering assumptions about stepped wedge designs: the case of Ebola vaccine research.

PubMed

Doussau, Adélaïde; Grady, Christine

2016-12-01

Ethical concerns about randomising persons to a no-treatment arm in the context of Ebola epidemic led to consideration of alternative designs. The stepped wedge (SW) design, in which participants or clusters are randomised to receive an intervention at different time points, gained popularity. Common arguments in favour of using this design are (1) when an intervention is likely to do more good than harm, (2) all participants should receive the experimental intervention at some time point during the study and (3) the design might be preferable for practical reasons. We examine these assumptions when considering Ebola vaccine research. First, based on the claim that a stepped wedge design is indicated when it is likely that the intervention will do more good than harm, we reviewed published and ongoing SW trials to explore previous use of this design to test experimental drugs or vaccines, and found that SW design has never been used for trials of experimental drugs or vaccines. Given that Ebola vaccines were all experimental with no prior efficacy data, the use of a stepped wedge design would have been unprecedented. Second, we show that it is rarely true that all participants receive the intervention in SW studies, but rather, depending on certain design features, all clusters receive the intervention. Third, we explore whether the SW design is appealing for feasibility reasons and point out that there is significant complexity. In the setting of the Ebola epidemic, spatiotemporal variation may have posed problematic challenges to a stepped wedge design for vaccine research. Finally, we propose a set of points to consider for scientific reviewers and ethics committees regarding proposals for SW designs. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Examining Development of Curriculum Knowledge of Prospective Mathematics Teachers

ERIC Educational Resources Information Center

Sahin, Ömer; Soylu, Yasin

2017-01-01

Explanatory-confirmatory research design, one of the mixed methods research designs, was used in this study to investigate Curriculum Knowledge developments of prospective teachers regarding algebra. Cross-sectional study method, as a type of descriptive research and one of the non-experimental research designs, was used to collect quantitative…

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…

Experimental design of laminar proportional amplifiers

NASA Technical Reports Server (NTRS)

Hellbaum, R. F.

1976-01-01

An experimental program was initiated at Langley Research Center to study the effects of various parameters on the design of laminar proportional beam deflection amplifiers. Matching and staging of amplifiers to obtain high-pressure gain was also studied. Variable parameters were aspect ratio, setback, control length, receiver distance, receiver width, width of center vent, and bias pressure levels. Usable pressure gains from 4 to 19 per stage can now be achieved, and five amplifiers were staged together to yield pressure gains up to 2,000,000.

Experimental studies of two-stage centrifugal dust concentrator

NASA Astrophysics Data System (ADS)

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

2018-03-01

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

Preliminary results of the large experimental wind turbine phase of the national wind energy program

NASA Technical Reports Server (NTRS)

Thomas, R. L.; Sholes, T.; Sholes, J. E.

1975-01-01

The preliminary results of two projects in the development phase of reliable wind turbines designed to supply cost-competitive electrical energy were discussed. An experimental 100 kW wind turbine design and its status are first reviewed. The results of two parallel design studies for determining the configurations and power levels for wind turbines with minimum energy costs are also discussed. These studies predict wind energy costs of 1.5 to 7 cents per kW-h for wind turbines produced in quantities of 100 to 1000 per year and located at sites having average winds of 12 to 18 mph.

76 FR 27637 - Supplemental Priorities for Discretionary Grant Programs

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-12

.... Interrupted time series design means a type of quasi-experimental study (as defined in this notice) in which... design is an adaptation of an interrupted time series design that relies on the comparison of treatment... notice), interrupted time series designs (as defined in this notice), or regression discontinuity designs...

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…

Design, construction and testing of annular diffusers for high speed civil transportation combustor applications

NASA Technical Reports Server (NTRS)

Okhio, Cyril B.

1995-01-01

A theoretical and an experimental design study of subsonic flow through curved-wall annular diffusers is being carried out in order to establish the most pertinent design parameters for such devices and the implications of their application in the design of engine components in the aerospace industries. This investigation consists of solving numerically the full Navier Stokes and Continuity equations for the time-mean flow. Various models of turbulence are being evaluated for adoption throughout the study and comparisons would be made with experimental data where they exist. Assessment of diffuser performance based on the dissipated mechanical energy would also be made. The experimental work involves the application of Computer Aided Design software tool to the development of a suitable annular diffuser geometry and the subsequent downloading of such data to a CNC machine at Central State University. The results of the investigations are expected to indicate that more cost effective component design of such devices as effective component design of such devices as diffusers which normally contain complex flows can still be achieved. In this regard a review paper was accepted and presented at the First International Conference on High Speed Civil Transportation Research held at North Carolina A&T in December of 1994.

AMPS data management concepts. [Atmospheric, Magnetospheric and Plasma in Space experiment

NASA Technical Reports Server (NTRS)

Metzelaar, P. N.

1975-01-01

Five typical AMPS experiments were formulated to allow simulation studies to verify data management concepts. Design studies were conducted to analyze these experiments in terms of the applicable procedures, data processing and displaying functions. Design concepts for AMPS data management system are presented which permit both automatic repetitive measurement sequences and experimenter-controlled step-by-step procedures. Extensive use is made of a cathode ray tube display, the experimenters' alphanumeric keyboard, and the computer. The types of computer software required by the system and the possible choices of control and display procedures available to the experimenter are described for several examples. An electromagnetic wave transmission experiment illustrates the methods used to analyze data processing requirements.

[Problems of study designs with randomization, blinding and placebos].

PubMed

Heusser, P

1999-04-01

As randomised double-blind trials are not rarely demanded as a prerequisite for the scientific acceptance of complementary medicine, the author has analysed the soundness of this demand on the basis of the international literature. As a result there appeared a number of methodological, practical and ethical problems which question the theoretically deduced primal value of this study design relative to the needs of medical practice and of health insurance issues. The experimental instruments of randomisation, blinding and placebo deliberately exclude essential therapeutic factors which are integral elements of complementary medical concepts; therefore, it is suggested to supplement quantitatively and collectively oriented experimental research by non-experimental procedures, which adequately reflect the context- and practice-related individual reality.

75 FR 48672 - Pesticides; Revised Fee Schedule for Registration Applications

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-11

... follows B772 118 Amend or extend Experimental 3 11,577 Use Permit; minor changes to experimental design...,942 Experimental Use Permit; minor changes to experimental design; extend established temporary... revision of experimental design B780 121 New active ingredient; non- 12 144,704 food/feed; no SAP review...

Evaluation of a Social Marketing Campaign Targeting Preschool Children

ERIC Educational Resources Information Center

Johnson, Susan L.; Bellows, Laura; Beckstrom, Leslie; Anderson, Jennifer

2007-01-01

Objectives: To determine the effectiveness of a pilot social marketing program to increase preschoolers' willingness to try new foods. Methods: Four Head Start centers participated (2 experimental, 2 control) in a study using a quasi-experimental design. Experimental sites received a 12-week intervention developed using social marketing…

Counselor Effectiveness Through Radio Communication.

ERIC Educational Resources Information Center

Tentoni, Stuart C.

This study determined the effectiveness of the use of radio as a means of providing immediate feedback on student counselors in a practicum setting. Using a non-equivalent group experimental design, 10 experimental subjects were compared to 10 control subjects with respect to counselor effectiveness. The experimental subjects were given immediate…

Selection of Behavior Modification Programs Using the Simultaneous Treatment Design: Two Case Studies.

ERIC Educational Resources Information Center

Lowe, Warren C.

This report outlines the limitations and weaknesses of singlecase, time-series research designs, of which the ABAB design is one of the widely used. An alternative design, the simultaneous treatment design, proposed by Browning and Stover (1971), has several advantages over the ABAB design. The design enables an experimenter to simultaneously…

Combined application of mixture experimental design and artificial neural networks in the solid dispersion development.

PubMed

Medarević, Djordje P; Kleinebudde, Peter; Djuriš, Jelena; Djurić, Zorica; Ibrić, Svetlana

2016-01-01

This study for the first time demonstrates combined application of mixture experimental design and artificial neural networks (ANNs) in the solid dispersions (SDs) development. Ternary carbamazepine-Soluplus®-poloxamer 188 SDs were prepared by solvent casting method to improve carbamazepine dissolution rate. The influence of the composition of prepared SDs on carbamazepine dissolution rate was evaluated using d-optimal mixture experimental design and multilayer perceptron ANNs. Physicochemical characterization proved the presence of the most stable carbamazepine polymorph III within the SD matrix. Ternary carbamazepine-Soluplus®-poloxamer 188 SDs significantly improved carbamazepine dissolution rate compared to pure drug. Models developed by ANNs and mixture experimental design well described the relationship between proportions of SD components and percentage of carbamazepine released after 10 (Q10) and 20 (Q20) min, wherein ANN model exhibit better predictability on test data set. Proportions of carbamazepine and poloxamer 188 exhibited the highest influence on carbamazepine release rate. The highest carbamazepine release rate was observed for SDs with the lowest proportions of carbamazepine and the highest proportions of poloxamer 188. ANNs and mixture experimental design can be used as powerful data modeling tools in the systematic development of SDs. Taking into account advantages and disadvantages of both techniques, their combined application should be encouraged.

Factorial experimental design intended for the optimization of the alumina purification conditions

NASA Astrophysics Data System (ADS)

Brahmi, Mounaouer; Ba, Mohamedou; Hidri, Yassine; Hassen, Abdennaceur

2018-04-01

The objective of this study was to determine the optimal conditions by using the experimental design methodology for the removal of some impurities associated with the alumina. So, three alumina qualities of different origins were investigated under the same conditions. The application of full-factorial designs on the samples of different qualities of alumina has followed the removal rates of the sodium oxide. However, a factorial experimental design was developed to describe the elimination of sodium oxide associated with the alumina. The experimental results showed that chemical analyze followed by XRF prior treatment of the samples, provided a primary idea concerning these prevailing impurities. Therefore, it appeared that the sodium oxide constituted the largest amount among all impurities. After the application of experimental design, analysis of the effectors different factors and their interactions showed that to have a better result, we should reduce the alumina quantity investigated and by against increase the stirring time for the first two samples, whereas, it was necessary to increase the alumina quantity in the case of the third sample. To expand and improve this research, we should take into account all existing impurities, since we found during this investigation that the levels of partial impurities increased after the treatment.

Strength of bolted wood joints with various ratios of member thicknesses

Treesearch

Thomas Lee Wilkinson

1978-01-01

Procedures have been recommended–such as in the National Design Specification–for design of bolted joints in wood members where the side members are thicker or thinner than half the main member thickness. However, these recommendations have had no experimental verification up to now. The same is true for joints with other than three members. This study experimentally...

Implications of groundwater hydrology to buffer design in the southeastern U.S.

Treesearch

Ge Sun; James M. Vose; Devendra M. Amatya; Carl Trettin; Steven G. McNulty

2008-01-01

The objective of this study was to examine the hydrologic processes of shallow groundwater to better define and design forest riparian management zones in headwater streams of two contrasting terrains in the southeastern U.S. We employed two long-term experimental watersheds, WS80 (206 ha) and WS77 (151 ha) at the Santee Experimental Forests in South Carolina, and WS2...

An Evaluation of the Effectiveness of the Remediation Plus Program on Improving Reading Achievement of Students in the Marinette (WI) School District

ERIC Educational Resources Information Center

Corcoran, Roisin P.; Ross, Steven M.

2015-01-01

The study was implemented in the Title I Marinette School District using a randomized experimental design and parallel quasi experimental design spanning three grades 1-3 in 3 district elementary schools. The Remediation Plus Intervention is a multi-sensory, systematic synthetic phonics curriculum for all ages of students who struggle with…

75 FR 42081 - Proposed Information Collection; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-20

.... This study uses an experimental design to assess the outcomes associated with participation in national... reduce paperwork and respondent burden, conducts a pre-clearance consultation program to provide the... participation in youth corps may lead to measurable outcomes for participants. The study uses an experimental...

Development and Validation of a Rubric for Diagnosing Students’ Experimental Design Knowledge and Difficulties

PubMed Central

Dasgupta, Annwesa P.; Anderson, Trevor R.

2014-01-01

It is essential to teach students about experimental design, as this facilitates their deeper understanding of how most biological knowledge was generated and gives them tools to perform their own investigations. Despite the importance of this area, surprisingly little is known about what students actually learn from designing biological experiments. In this paper, we describe a rubric for experimental design (RED) that can be used to measure knowledge of and diagnose difficulties with experimental design. The development and validation of the RED was informed by a literature review and empirical analysis of undergraduate biology students’ responses to three published assessments. Five areas of difficulty with experimental design were identified: the variable properties of an experimental subject; the manipulated variables; measurement of outcomes; accounting for variability; and the scope of inference appropriate for experimental findings. Our findings revealed that some difficulties, documented some 50 yr ago, still exist among our undergraduate students, while others remain poorly investigated. The RED shows great promise for diagnosing students’ experimental design knowledge in lecture settings, laboratory courses, research internships, and course-based undergraduate research experiences. It also shows potential for guiding the development and selection of assessment and instructional activities that foster experimental design. PMID:26086658

Experimental study of burnout in channels with twisted fuel rods

NASA Astrophysics Data System (ADS)

Bol'Shakov, V. V.; Bashkirtsev, S. M.; Kobzar', L. L.; Morozov, A. G.

2007-05-01

The results of experimental studies of pressure drop and critical heat flux in the models of fuel assemblies (FAs) with fuel rod simulators twisted relative to the longitudinal axis and a three-ray cross section are considered. The experimental data are compared to the results obtained with the use of techniques adopted for design calculations with fuel rod bundles of type-VVER reactors.

Promoting Experimental Problem-Solving Ability in Sixth-Grade Students through Problem-Oriented Teaching of Ecology: Findings of an Intervention Study in a Complex Domain

ERIC Educational Resources Information Center

Roesch, Frank; Nerb, Josef; Riess, Werner

2015-01-01

Our study investigated whether problem-oriented designed ecology lessons with phases of direct instruction and of open experimentation foster the development of cross-domain and domain-specific components of "experimental problem-solving ability" better than conventional lessons in science. We used a paper-and-pencil test to assess…

Highly Efficient Design-of-Experiments Methods for Combining CFD Analysis and Experimental Data

NASA Technical Reports Server (NTRS)

Anderson, Bernhard H.; Haller, Harold S.

2009-01-01

It is the purpose of this study to examine the impact of "highly efficient" Design-of-Experiments (DOE) methods for combining sets of CFD generated analysis data with smaller sets of Experimental test data in order to accurately predict performance results where experimental test data were not obtained. The study examines the impact of micro-ramp flow control on the shock wave boundary layer (SWBL) interaction where a complete paired set of data exist from both CFD analysis and Experimental measurements By combining the complete set of CFD analysis data composed of fifteen (15) cases with a smaller subset of experimental test data containing four/five (4/5) cases, compound data sets (CFD/EXP) were generated which allows the prediction of the complete set of Experimental results No statistical difference were found to exist between the combined (CFD/EXP) generated data sets and the complete Experimental data set composed of fifteen (15) cases. The same optimal micro-ramp configuration was obtained using the (CFD/EXP) generated data as obtained with the complete set of Experimental data, and the DOE response surfaces generated by the two data sets were also not statistically different.

Duct flow nonuniformities study for space shuttle main engine

NASA Technical Reports Server (NTRS)

Thoenes, J.

1985-01-01

To improve the Space Shuttle Main Engine (SSME) design and for future use in the development of generation rocket engines, a combined experimental/analytical study was undertaken with the goals of first, establishing an experimental data base for the flow conditions in the SSME high pressure fuel turbopump (HPFTP) hot gas manifold (HGM) and, second, setting up a computer model of the SSME HGM flow field. Using the test data to verify the computer model it should be possible in the future to computationally scan contemplated advanced design configurations and limit costly testing to the most promising design. The effort of establishing and using the computer model is detailed. The comparison of computational results and experimental data observed clearly demonstrate that computational fluid mechanics (CFD) techniques can be used successfully to predict the gross features of three dimensional fluid flow through configurations as intricate as the SSME turbopump hot gas manifold.

Critical evaluation of challenges and future use of animals in experimentation for biomedical research.

PubMed

Singh, Vijay Pal; Pratap, Kunal; Sinha, Juhi; Desiraju, Koundinya; Bahal, Devika; Kukreti, Ritushree

2016-12-01

Animal experiments that are conducted worldwide contribute to significant findings and breakthroughs in the understanding of the underlying mechanisms of various diseases, bringing up appropriate clinical interventions. However, their predictive value is often low, leading to translational failure. Problems like translational failure of animal studies and poorly designed animal experiments lead to loss of animal lives and less translatable data which affect research outcomes ethically and economically. Due to increasing complexities in animal usage with changes in public perception and stringent guidelines, it is becoming difficult to use animals for conducting studies. This review deals with challenges like poor experimental design and ethical concerns and discusses key concepts like sample size, statistics in experimental design, humane endpoints, economic assessment, species difference, housing conditions, and systematic reviews and meta-analyses that are often neglected. If practiced, these strategies can refine the procedures effectively and help translate the outcomes efficiently. © The Author(s) 2016.

Critical evaluation of challenges and future use of animals in experimentation for biomedical research

PubMed Central

Singh, Vijay Pal; Pratap, Kunal; Sinha, Juhi; Desiraju, Koundinya; Bahal, Devika; Kukreti, Ritushree

2016-01-01

Animal experiments that are conducted worldwide contribute to significant findings and breakthroughs in the understanding of the underlying mechanisms of various diseases, bringing up appropriate clinical interventions. However, their predictive value is often low, leading to translational failure. Problems like translational failure of animal studies and poorly designed animal experiments lead to loss of animal lives and less translatable data which affect research outcomes ethically and economically. Due to increasing complexities in animal usage with changes in public perception and stringent guidelines, it is becoming difficult to use animals for conducting studies. This review deals with challenges like poor experimental design and ethical concerns and discusses key concepts like sample size, statistics in experimental design, humane endpoints, economic assessment, species difference, housing conditions, and systematic reviews and meta-analyses that are often neglected. If practiced, these strategies can refine the procedures effectively and help translate the outcomes efficiently. PMID:27694614

Solar-Diesel Hybrid Power System Optimization and Experimental Validation

NASA Astrophysics Data System (ADS)

Jacobus, Headley Stewart

As of 2008 1.46 billion people, or 22 percent of the World's population, were without electricity. Many of these people live in remote areas where decentralized generation is the only method of electrification. Most mini-grids are powered by diesel generators, but new hybrid power systems are becoming a reliable method to incorporate renewable energy while also reducing total system cost. This thesis quantifies the measurable Operational Costs for an experimental hybrid power system in Sierra Leone. Two software programs, Hybrid2 and HOMER, are used during the system design and subsequent analysis. Experimental data from the installed system is used to validate the two programs and to quantify the savings created by each component within the hybrid system. This thesis bridges the gap between design optimization studies that frequently lack subsequent validation and experimental hybrid system performance studies.

Adaptive design of visual perception experiments

NASA Astrophysics Data System (ADS)

O'Connor, John D.; Hixson, Jonathan; Thomas, James M., Jr.; Peterson, Matthew S.; Parasuraman, Raja

2010-04-01

Meticulous experimental design may not always prevent confounds from affecting experimental data acquired during visual perception experiments. Although experimental controls reduce the potential effects of foreseen sources of interference, interaction, or noise, they are not always adequate for preventing the confounding effects of unforeseen forces. Visual perception experimentation is vulnerable to unforeseen confounds because of the nature of the associated cognitive processes involved in the decision task. Some confounds are beyond the control of experimentation, such as what a participant does immediately prior to experimental participation, or the participant's attitude or emotional state. Other confounds may occur through ignorance of practical control methods on the part of the experiment's designer. The authors conducted experiments related to experimental fatigue and initially achieved significant results that were, upon re-examination, attributable to a lack of adequate controls. Re-examination of the original results and the processes and events that led to them yielded a second experimental design with more experimental controls and significantly different results. The authors propose that designers of visual perception experiments can benefit from planning to use a test-fix-test or adaptive experimental design cycle, so that unforeseen confounds in the initial design can be remedied.

Experimental validation of systematically designed acoustic hyperbolic meta material slab exhibiting negative refraction

NASA Astrophysics Data System (ADS)

Christiansen, Rasmus E.; Sigmund, Ole

2016-09-01

This Letter reports on the experimental validation of a two-dimensional acoustic hyperbolic metamaterial slab optimized to exhibit negative refractive behavior. The slab was designed using a topology optimization based systematic design method allowing for tailoring the refractive behavior. The experimental results confirm the predicted refractive capability as well as the predicted transmission at an interface. The study simultaneously provides an estimate of the attenuation inside the slab stemming from the boundary layer effects—insight which can be utilized in the further design of the metamaterial slabs. The capability of tailoring the refractive behavior opens possibilities for different applications. For instance, a slab exhibiting zero refraction across a wide angular range is capable of funneling acoustic energy through it, while a material exhibiting the negative refractive behavior across a wide angular range provides lensing and collimating capabilities.

Experimental Design for Stochastic Models of Nonlinear Signaling Pathways Using an Interval-Wise Linear Noise Approximation and State Estimation.

PubMed

Zimmer, Christoph

2016-01-01

Computational modeling is a key technique for analyzing models in systems biology. There are well established methods for the estimation of the kinetic parameters in models of ordinary differential equations (ODE). Experimental design techniques aim at devising experiments that maximize the information encoded in the data. For ODE models there are well established approaches for experimental design and even software tools. However, data from single cell experiments on signaling pathways in systems biology often shows intrinsic stochastic effects prompting the development of specialized methods. While simulation methods have been developed for decades and parameter estimation has been targeted for the last years, only very few articles focus on experimental design for stochastic models. The Fisher information matrix is the central measure for experimental design as it evaluates the information an experiment provides for parameter estimation. This article suggest an approach to calculate a Fisher information matrix for models containing intrinsic stochasticity and high nonlinearity. The approach makes use of a recently suggested multiple shooting for stochastic systems (MSS) objective function. The Fisher information matrix is calculated by evaluating pseudo data with the MSS technique. The performance of the approach is evaluated with simulation studies on an Immigration-Death, a Lotka-Volterra, and a Calcium oscillation model. The Calcium oscillation model is a particularly appropriate case study as it contains the challenges inherent to signaling pathways: high nonlinearity, intrinsic stochasticity, a qualitatively different behavior from an ODE solution, and partial observability. The computational speed of the MSS approach for the Fisher information matrix allows for an application in realistic size models.

Experimental Test Rig for Optimal Control of Flexible Space Robotic Arms

DTIC Science & Technology

2016-12-01

was used to refine the test bed design and the experimental workflow. Three concepts incorporated various strategies to design a robust flexible link...used to refine the test bed design and the experimental workflow. Three concepts incorporated various strategies to design a robust flexible link... designed to perform the experimentation . The first and second concepts use traditional elastic springs in varying configurations while a third uses a

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…

Study design elements for rigorous quasi-experimental comparative effectiveness research.

PubMed

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.

Understanding Electrochemistry Concepts Using the Predict-Observe-Explain Strategy

ERIC Educational Resources Information Center

Karamustafaoglu, Sevilay; Mamlok-Naaman, Rachel

2015-01-01

The current study deals with freshman students who study at the Department of Science at the Faculty of Education. The aim of the study was to investigate the effect of teaching electrochemistry concepts using Predict-Observe-Explain (POE) strategy. The study was quasi-experimental design using 20 students each in the experimental group (EG) and…

Graphic Organizers and Students with Learning Disabilities: A Meta-Analysis

ERIC Educational Resources Information Center

Dexter, Douglas D.; Hughes, Charles A.

2011-01-01

This meta-analysis reviews experimental and quasi-experimental studies in which upper-elementary, intermediate, and secondary students with learning disabilities learned from graphic organizers. Following an exhaustive search for studies meeting specified design criteria, 55 standardized mean effect sizes were extracted from 16 articles involving…

Intermediate experimental vehicle, ESA program aerodynamics-aerothermodynamics key technologies for spacecraft design and successful flight

NASA Astrophysics Data System (ADS)

Dutheil, Sylvain; Pibarot, Julien; Tran, Dac; Vallee, Jean-Jacques; Tribot, Jean-Pierre

2016-07-01

With the aim of placing Europe among the world's space players in the strategic area of atmospheric re-entry, several studies on experimental vehicle concepts and improvements of critical re-entry technologies have paved the way for the flight of an experimental space craft. The successful flight of the Intermediate eXperimental Vehicle (IXV), under ESA's Future Launchers Preparatory Programme (FLPP), is definitively a significant step forward from the Atmospheric Reentry Demonstrator flight (1998), establishing Europe as a key player in this field. The IXV project objectives were the design, development, manufacture and ground and flight verification of an autonomous European lifting and aerodynamically controlled reentry system, which is highly flexible and maneuverable. The paper presents, the role of aerodynamics aerothermodynamics as part of the key technologies for designing an atmospheric re-entry spacecraft and securing a successful flight.

Experimental and Computational Investigation of a Translating-Throat Single-Expansion-Ramp Nozzle

NASA Technical Reports Server (NTRS)

Deere, Karen A.; Asbury, Scott C.

1999-01-01

An experimental and computational study was conducted on a high-speed, single-expansion-ramp nozzle (SERN) concept designed for efficient off-design performance. The translating-throat SERN concept adjusts the axial location of the throat to provide a variable expansion ratio and allow a more optimum jet exhaust expansion at various flight conditions in an effort to maximize nozzle performance. Three design points (throat locations) were investigated to simulate the operation of this concept at subsonic-transonic, low supersonic, and high supersonic flight conditions. The experimental study was conducted in the jet exit test facility at the Langley Research Center. Internal nozzle performance was obtained at nozzle pressure ratios (NPR's) up to 13 for six nozzles with design nozzle pressure ratios near 9, 42, and 102. Two expansion-ramp surfaces, one concave and one convex, were tested for each design point. Paint-oil flow and focusing schlieren flow visualization techniques were utilized to acquire additional flow data at selected NPR'S. The Navier-Stokes code, PAB3D, was used with a two-equation k-e turbulence model for the computational study. Nozzle performance characteristics were predicted at nozzle pressure ratios of 5, 9, and 13 for the concave ramp, low Mach number nozzle and at 10, 13, and 102 for the concave ramp, high Mach number nozzle.

Quasi-experimental designs in practice-based research settings: design and implementation considerations.

PubMed

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.

Implementation of "Quality by Design (QbD)" Approach for the Development of 5-Fluorouracil Loaded Thermosensitive Hydrogel.

PubMed

Dalwadi, Chintan; Patel, Gayatri

2016-01-01

The purpose of this study was to investigate Quality by Design (QbD) principle for the preparation of hydrogel products to prove both practicability and utility of executing QbD concept to hydrogel based controlled release systems. Product and process understanding will help in decreasing the variability of critical material and process parameters, which give quality product output and reduce the risk. This study includes the identification of the Quality Target Product Profiles (QTPPs) and Critical Quality Attributes (CQAs) from literature or preliminary studies. To identify and control the variability in process and material attributes, two tools of QbD was utilized, Quality Risk Management (QRM) and Experimental Design. Further, it helps to identify the effect of these attributes on CQAs. Potential risk factors were identified from fishbone diagram and screened by risk assessment and optimized by 3-level 2- factor experimental design with center points in triplicate, to analyze the precision of the target process. This optimized formulation was further characterized by gelling time, gelling temperature, rheological parameters, in-vitro biodegradation and in-vitro drug release. Design space was created using experimental design tool that gives the control space and working within this controlled space reduces all the failure modes below the risk level. In conclusion, QbD approach with QRM tool provides potent and effectual pyramid to enhance the quality into the hydrogel.

Pasadena City College SIGI Project Research Design. Pilot Study.

ERIC Educational Resources Information Center

Risser, John J.; Tulley, John E.

A pilot study evaluation of SIGI (System of Interactive Guidance and Information) at Pasadena City College in 1974-75 tested the effectiveness of an experimental research design for an expanded field test of the system the following year. (SIGI is a computer based career guidance program designed by Educational Testing Service to assist community…

The Design of Time-Series Comparisons under Resource Constraints.

ERIC Educational Resources Information Center

Willemain, Thomas R.; Hartunian, Nelson S.

1982-01-01

Two methods for dividing an interrupted time-series study between baseline and experimental phases when study resources are limited are compared. In fixed designs, the baseline duration is predetermined. In flexible designs the baseline duration is contingent on remaining resources and the match of results to prior expectations of the evaluator.…

Group-Based Life Design Counseling in an Italian Context

ERIC Educational Resources Information Center

Di Fabio, Annamaria; Maree, Jacobus Gideon

2012-01-01

This study examined the effectiveness of group-based Life Design Counseling using the Career-Story Interview. Written exercises were used to implement the seven topics in the Career-Story Interview. The present study employed an experimental design that involved two groups of Italian entrepreneurs from the agricultural and trade sectors, namely an…

Analyzing the Effect of Metaconceptual Teaching Practices on Students' Understanding of Force and Motion Concepts

ERIC Educational Resources Information Center

Yuruk, Nejla; Beeth, Michael E.; Andersen, Christopher

2009-01-01

This study investigated the effect of metaconceptual teaching interventions on students' understanding of force and motion concepts. A multimethod research design including quasi-experimental design and case study designs was employed to compare the effect of the metaconceptual activities and traditional instruction and investigate students'…

Alternating treatments design: one strategy for comparing the effects of two treatments in a single subject.

PubMed Central

Barlow, D H; Hayes, S C

1979-01-01

A little used and often confused design, capable of comparing two treatments within a single subject, has been termed, variously, a multielement baseline design, a multiple schedule design, and a randomization design. The background of these terms is reviewed, and a new, more descriptive term, Alternating Treatments Design, is proposed. Critical differences between this design and a Simultaneous Treatment Design are outlined, and experimental questions answerable by each design are noted. Potential problems with multiple treatment interference in this procedure are divided into sequential confounding, carryover effects, and alternation effects and the importance of these issues vis-a-vis other single-case experimental designs is considered. Methods of minimizing multiple treatment interference as well as methods of studying these effects are outlined. Finally, appropriate uses of Alternating Treatments Designs are described and discussed in the context of recent examples. PMID:489478

Systematic review of sensory integration therapy for individuals with disabilities: Single case design studies.

PubMed

Leong, H M; Carter, Mark; Stephenson, Jennifer

2015-12-01

Sensory integration therapy (SIT) is a controversial intervention that is widely used for people with disabilities. Systematic analysis was conducted on the outcomes of 17 single case design studies on sensory integration therapy for people with, or at-risk of, a developmental or learning disability, disorder or delay. An assessment of the quality of methodology of the studies found most used weak designs and poor methodology, with a tendency for higher quality studies to produce negative results. Based on limited comparative evidence, functional analysis-based interventions for challenging behavior were more effective that SIT. Overall the studies do not provide convincing evidence for the efficacy of sensory integration therapy. Given the findings of the present review and other recent analyses it is advised that the use of SIT be limited to experimental contexts. Issues with the studies and possible improvements for future research are discussed including the need to employ designs that allow for adequate demonstration of experimental control. Copyright © 2015 Elsevier Ltd. All rights reserved.

Experimental investigation of reinforced bonded joints for composite laminates.

PubMed

Bisagni, Chiara; Furfari, Domenico; Pacchione, Marco

2018-02-01

An experimental study has been carried out to investigate the behaviour of co-bonded carbon fibre reinforced plastics joints with a novel design incorporating a through the thickness local reinforcement. Different specimens were manufactured to investigate static and fatigue behaviour, as well as delamination size after impact and damage tolerance characteristics. The mechanical performances of the specimens with local reinforcement, consisting of the insertion of spiked thin metal sheets between co-bonded laminates, were compared with those ones obtained from specimens with purely co-bonded joints. This novel design demonstrated by tests that damage progression under cycling load results significantly delayed by the reinforcements. A significant number of experimental results were obtained that can be used to define preliminary design guidelines.

Pliocene Model Intercomparison (PlioMIP) Phase 2: Scientific Objectives and Experimental Design

NASA Technical Reports Server (NTRS)

Haywood, A. M.; Dowsett, H. J.; Dolan, A. M.; Rowley, D.; Abe-Ouchi, A.; Otto-Bliesner, B.; Chandler, M. A.; Hunter, S. J.; Lunt, D. J.; Pound, M.;

Experimental investigation of reinforced bonded joints for composite laminates

PubMed Central

Bisagni, Chiara; Furfari, Domenico; Pacchione, Marco

2017-01-01

An experimental study has been carried out to investigate the behaviour of co-bonded carbon fibre reinforced plastics joints with a novel design incorporating a through the thickness local reinforcement. Different specimens were manufactured to investigate static and fatigue behaviour, as well as delamination size after impact and damage tolerance characteristics. The mechanical performances of the specimens with local reinforcement, consisting of the insertion of spiked thin metal sheets between co-bonded laminates, were compared with those ones obtained from specimens with purely co-bonded joints. This novel design demonstrated by tests that damage progression under cycling load results significantly delayed by the reinforcements. A significant number of experimental results were obtained that can be used to define preliminary design guidelines. PMID:29568127

76 FR 30926 - Notice of Proposed Information Collection Requests

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-27

... North Carolina study will use a quasi-experimental design using propensity score matching. State end-of... student learning will be compared to a traditional FLVS U.S. History online course using an experimental...

Single-stage experimental evaluation of tandem-airfoil rotor and stator blading for compressors. Part 5: Analysis and design of stages D and E

NASA Technical Reports Server (NTRS)

Brent, J. A.; Cheatham, J. G.; Clemmons, D. R.

1972-01-01

A conventional and a tandem bladed stage were designed for a comparative experimental evaluation in a 0.8 hub/tip ratio single-stage compressor. Based on a preliminary design study, a radially constant work input distribution was selected for the rotor designs. Velocity diagrams and blade leading and trailing edge angles selected for the conventional rotor and stator were used in the design of the tandem blading. The effects of axial velocity ratio and secondary flow on turning were included in the selection of blade leading and trailing edge angles. Design values of rotor tip velocity and stage pressure ratio were 757 ft/sec and 1.26, respectively.

76 FR 32171 - Applications for New Awards; Investing in Innovation Fund

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-03

... conflict of interest. Interrupted time series design \\5\\ means a type of quasi- experimental study in... single case design is an adaptation of an interrupted time series design that relies on the comparison of...), interrupted time series designs (as defined in this notice), or regression discontinuity designs (as defined...

76 FR 32159 - Applications for New Awards; Investing in Innovation Fund

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-03

... conflict of interest. Interrupted time series design \\5\\ means a type of quasi- experimental study in which... design is an adaptation of an interrupted time series design that relies on the comparison of treatment...), interrupted time series designs (as defined in this notice), or regression discontinuity designs (as defined...

Plant Disease Severity Assessment-How Rater Bias, Assessment Method, and Experimental Design Affect Hypothesis Testing and Resource Use Efficiency.

PubMed

Chiang, Kuo-Szu; Bock, Clive H; Lee, I-Hsuan; El Jarroudi, Moussa; Delfosse, Philippe

2016-12-01

The effect of rater bias and assessment method on hypothesis testing was studied for representative experimental designs for plant disease assessment using balanced and unbalanced data sets. Data sets with the same number of replicate estimates for each of two treatments are termed "balanced" and those with unequal numbers of replicate estimates are termed "unbalanced". The three assessment methods considered were nearest percent estimates (NPEs), an amended 10% incremental scale, and the Horsfall-Barratt (H-B) scale. Estimates of severity of Septoria leaf blotch on leaves of winter wheat were used to develop distributions for a simulation model. The experimental designs are presented here in the context of simulation experiments which consider the optimal design for the number of specimens (individual units sampled) and the number of replicate estimates per specimen for a fixed total number of observations (total sample size for the treatments being compared). The criterion used to gauge each method was the power of the hypothesis test. As expected, at a given fixed number of observations, the balanced experimental designs invariably resulted in a higher power compared with the unbalanced designs at different disease severity means, mean differences, and variances. Based on these results, with unbiased estimates using NPE, the recommended number of replicate estimates taken per specimen is 2 (from a sample of specimens of at least 30), because this conserves resources. Furthermore, for biased estimates, an apparent difference in the power of the hypothesis test was observed between assessment methods and between experimental designs. Results indicated that, regardless of experimental design or rater bias, an amended 10% incremental scale has slightly less power compared with NPEs, and that the H-B scale is more likely than the others to cause a type II error. These results suggest that choice of assessment method, optimizing sample number and number of replicate estimates, and using a balanced experimental design are important criteria to consider to maximize the power of hypothesis tests for comparing treatments using disease severity estimates.

Time-oriented experimental design method to optimize hydrophilic matrix formulations with gelation kinetics and drug release profiles.

PubMed

Shin, Sangmun; Choi, Du Hyung; Truong, Nguyen Khoa Viet; Kim, Nam Ah; Chu, Kyung Rok; Jeong, Seong Hoon

2011-04-04

A new experimental design methodology was developed by integrating the response surface methodology and the time series modeling. The major purposes were to identify significant factors in determining swelling and release rate from matrix tablets and their relative factor levels for optimizing the experimental responses. Properties of tablet swelling and drug release were assessed with ten factors and two default factors, a hydrophilic model drug (terazosin) and magnesium stearate, and compared with target values. The selected input control factors were arranged in a mixture simplex lattice design with 21 experimental runs. The obtained optimal settings for gelation were PEO, LH-11, Syloid, and Pharmacoat with weight ratios of 215.33 (88.50%), 5.68 (2.33%), 19.27 (7.92%), and 3.04 (1.25%), respectively. The optimal settings for drug release were PEO and citric acid with weight ratios of 191.99 (78.91%) and 51.32 (21.09%), respectively. Based on the results of matrix swelling and drug release, the optimal solutions, target values, and validation experiment results over time were similar and showed consistent patterns with very small biases. The experimental design methodology could be a very promising experimental design method to obtain maximum information with limited time and resources. It could also be very useful in formulation studies by providing a systematic and reliable screening method to characterize significant factors in the sustained release matrix tablet. Copyright © 2011 Elsevier B.V. All rights reserved.

Bibliography on Cold Regions Science and Technology. Cumulative Author Index. Volumes 28-32, Cumulative Subject Index. Volumes 28-32, Parts 1 and 2

DTIC Science & Technology

1978-12-01

Jr. 52-58, rusl 29.1345 Arctic ice model basin - design , construction, and operating experience Mathematical modelling of long-term non -stationary...crane KS-6362KhL designed for the North [1974, p.3-4, F11ppov, A.M. rusl 29-266 Experimental study of the dynamics of ice-jam formation in talwaters of... experimental data on glass fiber insulating materials and their France. filrej 32-4349de ~preenseltritie use for a reliable design of insulations at

Driving Performance among Bioptic Telescope Users with Low Vision Two Years after Obtaining Their Driver's License: A Quasi-Experimental Study

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,…

Long-term longleaf pine (Pinus palustris Mill.) plantation studies on the palustris experimental forest: growing timber to provide habitat

Treesearch

J.C.G. Goelz; J.P. Barnett

2006-01-01

In 1935 the 7,500 acre palustris experimental forest was ordained by Congress to provide an area for conducting forestry research. However, work was already underway to establish research studies before the area was officially designated as an experimental forest within the boundaries of the Kistachie National Forest. At the time, much of the region consisted of...

Statistical analysis and application of quasi experiments to antimicrobial resistance intervention studies.

PubMed

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.

On the proper study design applicable to experimental balneology.

PubMed

Varga, Csaba

2016-08-01

The simple message of this paper is that it is the high time to reevaluate the strategies and optimize the efforts for investigation of thermal (spa) waters. Several articles trying to clear mode of action of medicinal waters have been published up to now. Almost all studies apply the unproven hypothesis, namely the inorganic ingredients are in close connection with healing effects of bathing. Change of paradigm would be highly necessary in this field taking into consideration the presence of several biologically active organic substances in these waters. A successful design for experimental mechanistic studies is approved.

Electrical coupled Morris-Lecar neurons: From design to pattern analysis

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

Binczak, S.; Behdad, R.; Rossé, M.

2016-06-08

In this study, an experimental electronic neuron based on Morris-Lecar model is presented, able to become an experimental unit tool to study collective association of robust coupled neurons. The circuit design is given according to the ionic currents of this model. A weak coupling of such neurons under Multisim Software can generate clusters based on the boundary conditions of the neurons and their initial conditions. For this study, we work in the region close to the fold bifurcation of limit cycles. In this region two limit cycles exist, one of the cycles is stable and another one is unstable.

Efficacy of a footbath for post-partum fatigue in South Korea: A quasi-experimental study.

PubMed

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.

Centrifugal slurry pump wear and hydraulic studies. Phase II report. Experimental studies

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

Mistry, D.; Cooper, P.; Biswas, C.

1983-01-01

This report describes the work performed by Ingersoll-Rand Research, Inc., under Phase II, Experimental Studies for the contract entitled, Centrifugal Slurry Pump Wear and Hydraulic Studies. This work was carried out for the US Department of Energy under Contract No. DE-AC-82PC50035. The basic development approach pursued this phase is presented, followed by a discussion on wear relationships. The analysis, which resulted in the development of a mathematical wear model relating pump life to some of the key design and operating parameters, is presented. The results, observations, and conclusions of the experimental investigation on small scale pumps that led to themore » selected design features for the prototype pump are discussed. The material investigation was performed at IRRI, ORNL and Battelle. The rationale for selecting the materials for testing, the test methods and apparatus used, and the results obtained are presented followed by a discussion on materials for a prototype pump. In addition, the prototype pump test facility description, as well as the related design and equipment details, are presented. 20 references, 53 figures, 13 tables.« less

Robust experimental design for optimizing the microbial inhibitor test for penicillin detection in milk.

PubMed

Nagel, O G; Molina, M P; Basílico, J C; Zapata, M L; Althaus, R L

2009-06-01

To use experimental design techniques and a multiple logistic regression model to optimize a microbiological inhibition test with dichotomous response for the detection of Penicillin G in milk. A 2(3) x 2(2) robust experimental design with two replications was used. The effects of three control factors (V: culture medium volume, S: spore concentration of Geobacillus stearothermophilus, I: indicator concentration), two noise factors (Dt: diffusion time, Ip: incubation period) and their interactions were studied. The V, S, Dt, Ip factors and V x S, V x Ip, S x Ip interactions showed significant effects. The use of 100 microl culture medium volume, 2 x 10(5) spores ml(-1), 60 min diffusion time and 3 h incubation period is recommended. In these elaboration conditions, the penicillin detection limit was of 3.9 microg l(-1), similar to the maximum residue limit (MRL). Of the two noise factors studied, the incubation period can be controlled by means of the culture medium volume and spore concentration. We were able to optimize bioassays of dichotomous response using an experimental design and logistic regression model for the detection of residues at the level of MRL, aiding in the avoidance of health problems in the consumer.

Modular biowaste monitoring system conceptual design

NASA Technical Reports Server (NTRS)

Fogal, G. L.

1974-01-01

The objective of the study was to define requirements and generate a conceptual design for a Modular Biowaste Monitoring System for specifically supporting shuttle life science experimental and diagnostic programs.

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…

Investigations of a Complex, Realistic Task: Intentional, Unsystematic, and Exhaustive Experimenters

ERIC Educational Resources Information Center

McElhaney, Kevin W.; Linn, Marcia C.

2011-01-01

This study examines how students' experimentation with a virtual environment contributes to their understanding of a complex, realistic inquiry problem. We designed a week-long, technology-enhanced inquiry unit on car collisions. The unit uses new technologies to log students' experimentation choices. Physics students (n = 148) in six diverse high…

The Experimental State of Mind in Elicitation: Illustrations from Tonal Fieldwork

ERIC Educational Resources Information Center

Yu, Kristine M.

2014-01-01

This paper illustrates how an "experimental state of mind", i.e. principles of experimental design, can inform hypothesis generation and testing in structured fieldwork elicitation. The application of these principles is demonstrated with case studies in toneme discovery. Pike's classic toneme discovery procedure is shown to be a special…

Comparative efficacy of two battery-powered toothbrushes on dental plaque removal.

PubMed

Ruhlman, C Douglas; Bartizek, Robert D; Biesbrock, Aaron R

2002-01-01

A number of clinical studies have consistently demonstrated that power toothbrushes deliver superior plaque removal compared to manual toothbrushes. Recently, a new power toothbrush (Crest SpinBrush) has been marketed with a design that fundamentally differs from other marketed power toothbrushes. Other power toothbrushes feature a small, round head designed to oscillate for enhanced cleaning between the teeth and below the gumline. The new power toothbrush incorporates a similar round oscillating head in conjunction with fixed bristles, which allows the user to brush with optimal manual brushing technique. The objective of this randomized, examiner-blind, parallel design study was to compare the plaque removal efficacy of a positive control power toothbrush (Colgate Actibrush) to an experimental toothbrush (Crest SpinBrush) following a single use among 59 subjects. Baseline plaque scores were 1.64 and 1.40 for the experimental toothbrush and control toothbrush treatment groups, respectively. With regard to all surfaces examined, the experimental toothbrush delivered an adjusted (via analysis of covariance) mean difference between baseline and post-brushing plaque scores of 0.47, while the control toothbrush delivered an adjusted mean difference of 0.33. On average, the difference between toothbrushes was statistically significant (p = 0.013). Because the covariate slope for the experimental group was statistically significantly greater (p = 0.001) than the slope for the control group, a separate slope model was used. Further analysis demonstrated that the experimental group had statistically significantly greater plaque removal than the control group for baseline plaque scores above 1.43. With respect to buccal surfaces, using a separate slope analysis of covariance, the experimental toothbrush delivered an adjusted mean difference between baseline and post-brushing plaque scores of 0.61, while the control toothbrush delivered an adjusted mean difference of 0.39. This difference between toothbrushes was also statistically significant (p = 0.002). On average, the results on lingual surfaces demonstrated similar directional scores favoring the experimental toothbrush; however these results did not achieve statistical significance. In conclusion, the experimental Crest SpinBrush, with its novel fixed and oscillating bristle design, was found to be more effective than the positive control Colgate Actibrush, which is designed with a small round oscillating cluster of bristles.

An experimental study of pressures on 60 deg Delta wings with leading edge vortex flaps

NASA Technical Reports Server (NTRS)

Marchman, J. F., III; Terry, J. E.; Donatelli, D. A.

1983-01-01

An experimental study was conducted in the Virginia Tech Stability Wind Tunnel to determine surface pressures over a 60 deg sweep delta wing with three vortex flap designs. Extensive pressure data was collected to provide a base data set for comparison with computational design codes and to allow a better understanding of the flow over vortex flaps. The results indicated that vortex flaps can be designed which will contain the leading edge vortex with no spillage onto the wing upper surface. However, the tests also showed that flaps designed without accounting for flap thickness will not be optimum and the result can be oversized flaps, early flap vortex reattachment and a second separation and vortex at the wing/flap hinge line.

Issues and recent advances in optimal experimental design for site investigation (Invited)

NASA Astrophysics Data System (ADS)

Nowak, W.

2013-12-01

This presentation provides an overview over issues and recent advances in model-based experimental design for site exploration. The addressed issues and advances are (1) how to provide an adequate envelope to prior uncertainty, (2) how to define the information needs in a task-oriented manner, (3) how to measure the expected impact of a data set that it not yet available but only planned to be collected, and (4) how to perform best the optimization of the data collection plan. Among other shortcomings of the state-of-the-art, it is identified that there is a lack of demonstrator studies where exploration schemes based on expert judgment are compared to exploration schemes obtained by optimal experimental design. Such studies will be necessary do address the often voiced concern that experimental design is an academic exercise with little improvement potential over the well- trained gut feeling of field experts. When addressing this concern, a specific focus has to be given to uncertainty in model structure, parameterizations and parameter values, and to related surprises that data often bring about in field studies, but never in synthetic-data based studies. The background of this concern is that, initially, conceptual uncertainty may be so large that surprises are the rule rather than the exception. In such situations, field experts have a large body of experience in handling the surprises, and expert judgment may be good enough compared to meticulous optimization based on a model that is about to be falsified by the incoming data. In order to meet surprises accordingly and adapt to them, there needs to be a sufficient representation of conceptual uncertainty within the models used. Also, it is useless to optimize an entire design under this initial range of uncertainty. Thus, the goal setting of the optimization should include the objective to reduce conceptual uncertainty. A possible way out is to upgrade experimental design theory towards real-time interaction with the ongoing site investigation, such that surprises in the data are immediately accounted for to restrict the conceptual uncertainty and update the optimization of the plan.

Simulation and Experimental Studies on Grain Selection and Structure Design of the Spiral Selector for Casting Single Crystal Ni-Based Superalloy.

PubMed

Zhang, Hang; Xu, Qingyan

2017-10-27

Grain selection is an important process in single crystal turbine blades manufacturing. Selector structure is a control factor of grain selection, as well as directional solidification (DS). In this study, the grain selection and structure design of the spiral selector were investigated through experimentation and simulation. A heat transfer model and a 3D microstructure growth model were established based on the Cellular automaton-Finite difference (CA-FD) method for the grain selector. Consequently, the temperature field, the microstructure and the grain orientation distribution were simulated and further verified. The average error of the temperature result was less than 1.5%. The grain selection mechanisms were further analyzed and validated through simulations. The structural design specifications of the selector were suggested based on the two grain selection effects. The structural parameters of the spiral selector, namely, the spiral tunnel diameter ( d w ), the spiral pitch ( h b ) and the spiral diameter ( h s ), were studied and the design criteria of these parameters were proposed. The experimental and simulation results demonstrated that the improved selector could accurately and efficiently produce a single crystal structure.

Simulation and Experimental Studies on Grain Selection and Structure Design of the Spiral Selector for Casting Single Crystal Ni-Based Superalloy

PubMed Central

Zhang, Hang; Xu, Qingyan

2017-01-01

Grain selection is an important process in single crystal turbine blades manufacturing. Selector structure is a control factor of grain selection, as well as directional solidification (DS). In this study, the grain selection and structure design of the spiral selector were investigated through experimentation and simulation. A heat transfer model and a 3D microstructure growth model were established based on the Cellular automaton-Finite difference (CA-FD) method for the grain selector. Consequently, the temperature field, the microstructure and the grain orientation distribution were simulated and further verified. The average error of the temperature result was less than 1.5%. The grain selection mechanisms were further analyzed and validated through simulations. The structural design specifications of the selector were suggested based on the two grain selection effects. The structural parameters of the spiral selector, namely, the spiral tunnel diameter (dw), the spiral pitch (hb) and the spiral diameter (hs), were studied and the design criteria of these parameters were proposed. The experimental and simulation results demonstrated that the improved selector could accurately and efficiently produce a single crystal structure. PMID:29077067

Design Considerations and Experimental Verification of a Rail Brake Armature Based on Linear Induction Motor Technology

NASA Astrophysics Data System (ADS)

Sakamoto, Yasuaki; Kashiwagi, Takayuki; Hasegawa, Hitoshi; Sasakawa, Takashi; Fujii, Nobuo

This paper describes the design considerations and experimental verification of an LIM rail brake armature. In order to generate power and maximize the braking force density despite the limited area between the armature and the rail and the limited space available for installation, we studied a design method that is suitable for designing an LIM rail brake armature; we considered adoption of a ring winding structure. To examine the validity of the proposed design method, we developed a prototype ring winding armature for the rail brakes and examined its electromagnetic characteristics in a dynamic test system with roller rigs. By repeating various tests, we confirmed that unnecessary magnetic field components, which were expected to be present under high speed running condition or when a ring winding armature was used, were not present. Further, the necessary magnetic field component and braking force attained the desired values. These studies have helped us to develop a basic design method that is suitable for designing the LIM rail brake armatures.

Accelerating Recovery from Poverty: Prevention Effects for Recently Separated Mothers

ERIC Educational Resources Information Center

Forgatch, Marion S.; DeGarmo, David S.

2007-01-01

This study evaluated benefits of a preventive intervention to the living standards of recently separated mothers. In the Oregon Divorce Study's randomized experimental design, data were collected 5 times over 30 months and evaluated with Hierarchical Linear Growth Models. Relative to their no-intervention control counterparts, experimental mothers…

Error analysis and prevention of cosmic ion-induced soft errors in static CMOS RAMs

NASA Astrophysics Data System (ADS)

Diehl, S. E.; Ochoa, A., Jr.; Dressendorfer, P. V.; Koga, P.; Kolasinski, W. A.

1982-12-01

Cosmic ray interactions with memory cells are known to cause temporary, random, bit errors in some designs. The sensitivity of polysilicon gate CMOS static RAM designs to logic upset by impinging ions has been studied using computer simulations and experimental heavy ion bombardment. Results of the simulations are confirmed by experimental upset cross-section data. Analytical models have been extended to determine and evaluate design modifications which reduce memory cell sensitivity to cosmic ions. A simple design modification, the addition of decoupling resistance in the feedback path, is shown to produce static RAMs immune to cosmic ray-induced bit errors.

Intuitive web-based experimental design for high-throughput biomedical data.

PubMed

Friedrich, Andreas; Kenar, Erhan; Kohlbacher, Oliver; Nahnsen, Sven

2015-01-01

Big data bioinformatics aims at drawing biological conclusions from huge and complex biological datasets. Added value from the analysis of big data, however, is only possible if the data is accompanied by accurate metadata annotation. Particularly in high-throughput experiments intelligent approaches are needed to keep track of the experimental design, including the conditions that are studied as well as information that might be interesting for failure analysis or further experiments in the future. In addition to the management of this information, means for an integrated design and interfaces for structured data annotation are urgently needed by researchers. Here, we propose a factor-based experimental design approach that enables scientists to easily create large-scale experiments with the help of a web-based system. We present a novel implementation of a web-based interface allowing the collection of arbitrary metadata. To exchange and edit information we provide a spreadsheet-based, humanly readable format. Subsequently, sample sheets with identifiers and metainformation for data generation facilities can be created. Data files created after measurement of the samples can be uploaded to a datastore, where they are automatically linked to the previously created experimental design model.

Designing artificial enzymes from scratch: Experimental study and mesoscale simulation

NASA Astrophysics Data System (ADS)

Komarov, Pavel V.; Zaborina, Olga E.; Klimova, Tamara P.; Lozinsky, Vladimir I.; Khalatur, Pavel G.; Khokhlov, Alexey R.

2016-09-01

We present a new concept for designing biomimetic analogs of enzymatic proteins; these analogs are based on the synthetic protein-like copolymers. α-Chymotrypsin is used as a prototype of the artificial catalyst. Our experimental study shows that in the course of free radical copolymerization of hydrophobic and hydrophilic monomers the target globular nanostructures of a "core-shell" morphology appear in a selective solvent. Using a mesoscale computer simulation, we show that the protein-like globules can have a large number of catalytic centers located at the hydrophobic core/hydrophilic shell interface.

Experimental studies of the Eppler 61 airfoil at low Reynolds numbers

NASA Technical Reports Server (NTRS)

Burns, T. F.; Mueller, T. J.

1982-01-01

The results of an experimental study to document the effects of separation and transition on the performance of an airfoil designed for low Reynolds number operation are presented. Lift, drag and flow visualization data were obtained for the Eppler 61 airfoil section for chord Reynolds numbers from about 30,000 to over 200,000. Smoke flow visualization was employed to document the boundary layer behavior and was correlated with the Eppler airfoil design and analysis computer program. Laminar separation, transition and turbulent reattachment had significant effects on the performance of this airfoil.

Reading Comprehension Interventions for Students with Autism Spectrum Disorders: A Synthesis of Research

ERIC Educational Resources Information Center

El Zein, Farah; Solis, Michael; Vaughn, Sharon; McCulley, Lisa

2014-01-01

The authors synthesized reading intervention studies conducted between 1980 and 2012 with K-12 students identified with autism spectrum disorders (ASD). Nine single-subject design studies, one quasi-experimental study, and two single-group design studies met the criteria for inclusion. Findings from the studies indicate that modifying…

Louisiana experimental base project : interim report No. 1.

DOT National Transportation Integrated Search

1979-11-01

The Louisiana Experimental Base Project is a research study evaluating the design/performance characteristics of three types of base courses as incorporated into comparable flexible pavement systems on a full-scale test road. Fourteen different test ...

Design and analysis issues in quantitative proteomics studies.

PubMed

Karp, Natasha A; Lilley, Kathryn S

2007-09-01

Quantitative proteomics is the comparison of distinct proteomes which enables the identification of protein species which exhibit changes in expression or post-translational state in response to a given stimulus. Many different quantitative techniques are being utilized and generate large datasets. Independent of the technique used, these large datasets need robust data analysis to ensure valid conclusions are drawn from such studies. Approaches to address the problems that arise with large datasets are discussed to give insight into the types of statistical analyses of data appropriate for the various experimental strategies that can be employed by quantitative proteomic studies. This review also highlights the importance of employing a robust experimental design and highlights various issues surrounding the design of experiments. The concepts and examples discussed within will show how robust design and analysis will lead to confident results that will ensure quantitative proteomics delivers.

Effects of a Web-based course on nursing skills and knowledge learning.

PubMed

Lu, Der-Fa; Lin, Zu-Chun; Li, Yun-Ju

2009-02-01

The purpose of the study was to assess the effectiveness of supplementing traditional classroom teaching with Web-based learning design when teaching intramuscular injection nursing skills. Four clusters of nursing students at a junior college in eastern Taiwan were randomly assigned to experimental and control groups. A total of 147 students (80 in the experimental group, 67 in the control group) completed the study. All participants received the same classroom lectures and skill demonstration. The experimental group interacted using a Web-based course and were able to view the content on demand. The students and instructor interacted via a chatroom, the bulletin board, and e-mail. Participants in the experimental group had significantly higher scores on both intramuscular injection knowledge and skill learning. A Web-based design can be an effective supplementing learning tool for teaching nursing knowledge and skills.

Impact of an inquiry unit on grade 4 students' science learning

NASA Astrophysics Data System (ADS)

Di Mauro, María Florencia; Furman, Melina

2016-09-01

This paper concerns the identification of teaching strategies that enhance the development of 4th grade students' experimental design skills at a public primary school in Argentina. Students' performance in the design of relevant experiments was evaluated before and after an eight-week intervention compared to a control group, as well as the persistence of this learning after eight months. The study involved a quasi-experimental longitudinal study with pre-test/post-test/delayed post-test measures, complemented with semi-structured interviews with randomly selected students. Our findings showed improvement in the experimental design skills as well as its sustainability among students working with the inquiry-based sequence. After the intervention, students were able to establish valid comparisons, propose pertinent designs and identify variables that should remain constant. Contrarily, students in the control group showed no improvement and continued to solve the posed problems based on prior beliefs. In summary, this paper shows evidence that implementing inquiry-based units involving problems set in cross-domain everyday situations that combine independent student work with teacher guidance significantly improves the development of scientific skills in real classroom contexts.

Study and design of cryogenic propellant acquisition systems. Volume 1: Design studies

NASA Technical Reports Server (NTRS)

Burge, G. W.; Blackmon, J. B.

1973-01-01

An in-depth study and selection of practical propellant surface tension acquisition system designs for two specific future cryogenic space vehicles, an advanced cryogenic space shuttle auxiliary propulsion system and an advanced space propulsion module is reported. A supporting laboratory scale experimental program was also conducted to provide design information critical to concept finalization and selection. Designs using localized pressure isolated surface tension screen devices were selected for each application and preliminary designs were generated. Based on these designs, large scale acquisition prototype hardware was designed and fabricated to be compatible with available NASA-MSFC feed system hardware.

A Study on the Efficacy of Project-Based Learning Approach on Social Studies Education: Conceptual Achievement and Academic Motivation

ERIC Educational Resources Information Center

Ilter, Ilhan

2014-01-01

In this research, an experimental study was carried out in social studies 4th grade students to develop students' conceptual achievement and motivation to succeed academically. The study aims to investigate the effectiveness of project-based learning (PBL) in social studies. A quasi-experimental research design (pre- and posttest) was used in the…

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.

Computational design and experimental validation of new thermal barrier systems

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

Guo, Shengmin

2015-03-31

The focus of this project is on the development of a reliable and efficient ab initio based computational high temperature material design method which can be used to assist the Thermal Barrier Coating (TBC) bond-coat and top-coat design. Experimental evaluations on the new TBCs are conducted to confirm the new TBCs’ properties. Southern University is the subcontractor on this project with a focus on the computational simulation method development. We have performed ab initio density functional theory (DFT) method and molecular dynamics simulation on screening the top coats and bond coats for gas turbine thermal barrier coating design and validationmore » applications. For experimental validations, our focus is on the hot corrosion performance of different TBC systems. For example, for one of the top coatings studied, we examined the thermal stability of TaZr 2.75O 8 and confirmed it’s hot corrosion performance.« less

PsyGlass: Capitalizing on Google Glass for naturalistic data collection.

PubMed

Paxton, Alexandra; Rodriguez, Kevin; Dale, Rick

2015-09-01

As commercial technology moves further into wearable technologies, cognitive and psychological scientists can capitalize on these devices to facilitate naturalistic research designs while still maintaining strong experimental control. One such wearable technology is Google Glass (Google, Inc.: www.google.com/glass), which can present wearers with audio and visual stimuli while tracking a host of multimodal data. In this article, we introduce PsyGlass, a framework for incorporating Google Glass into experimental work that is freely available for download and community improvement over time (www.github.com/a-paxton/PsyGlass). As a proof of concept, we use this framework to investigate dual-task pressures on naturalistic interaction. The preliminary study demonstrates how designs from classic experimental psychology may be integrated in naturalistic interactive designs with emerging technologies. We close with a series of recommendations for using PsyGlass and a discussion of how wearable technology more broadly may contribute to new or adapted naturalistic research designs.

Inflammasomes make the case for littermate-controlled experimental design in studying host-microbiota interactions.

PubMed

Mamantopoulos, Michail; Ronchi, Francesca; McCoy, Kathy D; Wullaert, Andy

2018-04-19

Several human diseases are thought to evolve due to a combination of host genetic mutations and environmental factors that include alterations in intestinal microbiota composition termed dysbiosis. Although in some cases, host genetics may shape the gut microbiota and enable it to provoke disease, experimentally disentangling cause and consequence in such host-microbe interactions requires strict control over non-genetic confounding factors. Mouse genetic studies previously proposed Nlrp6/ASC inflammasomes as innate immunity regulators of the intestinal ecosystem. In contrast, using littermate-controlled experimental setups, we recently showed that Nlrp6/ASC inflammasomes do not alter the gut microbiota composition. Our analyses indicated that maternal inheritance and long-term separate housing are non-genetic confounders that preclude the use of non-littermate mice when analyzing host genetic effects on intestinal ecology. Here, we summarize and discuss our gut microbiota analyses in inflammasome-deficient mice for illustrating the importance of littermate experimental design in studying host-microbiota interactions.

The Role of Formal Experiment Design in Hypersonic Flight System Technology Development

NASA Technical Reports Server (NTRS)

McClinton, Charles R.; Ferlemann, Shelly M.; Rock, Ken E.; Ferlemann, Paul G.

2002-01-01

Hypersonic airbreathing engine (scramjet) powered vehicles are being considered to replace conventional rocket-powered launch systems. Effective utilization of scramjet engines requires careful integration with the air vehicle. This integration synergistically combines aerodynamic forces with propulsive cycle functions of the engine. Due to the highly integrated nature of the hypersonic vehicle design problem, the large flight envelope, and the large number of design variables, the use of a statistical design approach in design is effective. Modern Design-of-Experiments (MDOE) has been used throughout the Hyper-X program, for both systems analysis and experimental testing. Application of MDOE fall into four categories: (1) experimental testing; (2) studies of unit phenomena; (3) refining engine design; and (4) full vehicle system optimization. The MDOE process also provides analytical models, which are also used to document lessons learned, supplement low-level design tools, and accelerate future studies. This paper will discuss the design considerations for scramjet-powered vehicles, specifics of MDOE utilized for Hyper-X, and present highlights from the use of these MDOE methods within the Hyper-X Program.

Optimization of the combined ultrasonic assisted/adsorption method for the removal of malachite green by gold nanoparticles loaded on activated carbon: experimental design.

PubMed

Roosta, M; Ghaedi, M; Shokri, N; Daneshfar, A; Sahraei, R; Asghari, A

2014-01-24

The present study was aimed to experimental design optimization applied to removal of malachite green (MG) from aqueous solution by ultrasound-assisted removal onto the gold nanoparticles loaded on activated carbon (Au-NP-AC). This nanomaterial was characterized using different techniques such as FESEM, TEM, BET, and UV-vis measurements. The effects of variables such as pH, initial dye concentration, adsorbent dosage (g), temperature and sonication time on MG removal were studied using central composite design (CCD) and the optimum experimental conditions were found with desirability function (DF) combined response surface methodology (RSM). Fitting the experimental equilibrium data to various isotherm models such as Langmuir, Freundlich, Tempkin and Dubinin-Radushkevich models show the suitability and applicability of the Langmuir model. Kinetic models such as pseudo -first order, pseudo-second order, Elovich and intraparticle diffusion models applicability was tested for experimental data and the second-order equation and intraparticle diffusion models control the kinetic of the adsorption process. The small amount of proposed adsorbent (0.015 g) is applicable for successful removal of MG (RE>99%) in short time (4.4 min) with high adsorption capacity (140-172 mg g(-1)). Copyright © 2013. Published by Elsevier B.V.

Design and experimental study on Fresnel lens of the combination of equal-width and equal-height of grooves

NASA Astrophysics Data System (ADS)

Guo, Limin; Liu, Youqiang; Huang, Rui; Wang, Zhiyong

2017-06-01

High concentrating PV systems rely on large Fresnel lens that must be precisely oriented in the direction of the Sun to maintain high concentration ratio. We propose a new Fresnel lens design method combining equal-width and equal-height of grooves in this paper based on the principle of focused spot maximum energy. In the ring band near the center of Fresnel lens, the design with equal-width grooves is applied, and when the given condition is reached, the design with equal-height grooves is introduced near the edges of the Fresnel lens, which ensures all the lens grooves are planar. In this paper, we establish a Fresnel lens design example model by Solidworks, and simulate it with the software ZEMAX. An experimental test platform is built to test, and the simulation correctness is proved by experiments. Experimental result shows the concentrating efficiency of this example is 69.3%, slightly lower than the simulation result 75.1%.

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

ERIC Educational Resources Information Center

Assenmacher, Matthew Benedict

2013-01-01

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

Effects of Outdoor School Ground Lessons on Students' Science Process Skills and Scientific Curiosity

ERIC Educational Resources Information Center

Ting, Kan Lin; Siew, Nyet Moi

2014-01-01

The purpose of this study was to investigate the effects of outdoor school ground lessons on Year Five students' science process skills and scientific curiosity. A quasi-experimental design was employed in this study. The participants in the study were divided into two groups, one subjected to the experimental treatment, defined as…

Sample size considerations for paired experimental design with incomplete observations of continuous outcomes.

PubMed

Zhu, Hong; Xu, Xiaohan; Ahn, Chul

2017-01-01

Paired experimental design is widely used in clinical and health behavioral studies, where each study unit contributes a pair of observations. Investigators often encounter incomplete observations of paired outcomes in the data collected. Some study units contribute complete pairs of observations, while the others contribute either pre- or post-intervention observations. Statistical inference for paired experimental design with incomplete observations of continuous outcomes has been extensively studied in literature. However, sample size method for such study design is sparsely available. We derive a closed-form sample size formula based on the generalized estimating equation approach by treating the incomplete observations as missing data in a linear model. The proposed method properly accounts for the impact of mixed structure of observed data: a combination of paired and unpaired outcomes. The sample size formula is flexible to accommodate different missing patterns, magnitude of missingness, and correlation parameter values. We demonstrate that under complete observations, the proposed generalized estimating equation sample size estimate is the same as that based on the paired t-test. In the presence of missing data, the proposed method would lead to a more accurate sample size estimate comparing with the crude adjustment. Simulation studies are conducted to evaluate the finite-sample performance of the generalized estimating equation sample size formula. A real application example is presented for illustration.

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…

Masked Visual Analysis: Minimizing Type I Error in Visually Guided Single-Case Design for Communication Disorders

ERIC Educational Resources Information Center

Byun, Tara McAllister; Hitchcock, Elaine R.; Ferron, John

2017-01-01

Purpose: Single-case experimental designs are widely used to study interventions for communication disorders. Traditionally, single-case experiments follow a response-guided approach, where design decisions during the study are based on participants' observed patterns of behavior. However, this approach has been criticized for its high rate of…

Comparing Technology-Related Teacher Professional Development Designs: A Multilevel Study of Teacher and Student Impacts

ERIC Educational Resources Information Center

Walker, Andrew; Recker, Mimi; Ye, Lei; Robertshaw, M. Brooke; Sellers, Linda; Leary, Heather

2012-01-01

This article presents a quasi-experimental study comparing the impact of two technology-related teacher professional development (TTPD) designs, aimed at helping junior high school science and mathematics teachers design online activities using the rapidly growing set of online learning resources available on the Internet. The first TTPD design…

A Comparison of Methods to Test for Mediation in Multisite Experiments

ERIC Educational Resources Information Center

Pituch, Keenan A.; Whittaker, Tiffany A.; Stapleton, Laura M.

2005-01-01

A Monte Carlo study extended the research of MacKinnon, Lockwood, Hoffman, West, and Sheets (2002) for single-level designs by examining the statistical performance of four methods to test for mediation in a multilevel experimental design. The design studied was a two-group experiment that was replicated across several sites, included a single…

Effects of a School-Based Sexuality Education Program on Peer Educators: The Teen PEP Model

ERIC Educational Resources Information Center

Jennings, J. M.; Howard, S.; Perotte, C. L.

2014-01-01

This study evaluated the impact of the Teen Prevention Education Program (Teen PEP), a peer-led sexuality education program designed to prevent unintended pregnancy and sexually transmitted infections (STIs) including HIV among high school students. The study design was a quasi-experimental, nonrandomized design conducted from May 2007 to May…

Improving Students' Conceptual Understanding of a Specific Content Learning: A Designed Teaching Sequence

ERIC Educational Resources Information Center

Ahmad, N. J.; Lah, Y. Che

2012-01-01

The efficacy of a teaching sequence designed for a specific content of learning of electrochemistry is described in this paper. The design of the teaching draws upon theoretical insights into perspectives on learning and empirical studies to improve the teaching of this topic. A case study involving two classes, the experimental and baseline…

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…

Pyviko: an automated Python tool to design gene knockouts in complex viruses with overlapping genes.

PubMed

Taylor, Louis J; Strebel, Klaus

2017-01-07

Gene knockouts are a common tool used to study gene function in various organisms. However, designing gene knockouts is complicated in viruses, which frequently contain sequences that code for multiple overlapping genes. Designing mutants that can be traced by the creation of new or elimination of existing restriction sites further compounds the difficulty in experimental design of knockouts of overlapping genes. While software is available to rapidly identify restriction sites in a given nucleotide sequence, no existing software addresses experimental design of mutations involving multiple overlapping amino acid sequences in generating gene knockouts. Pyviko performed well on a test set of over 240,000 gene pairs collected from viral genomes deposited in the National Center for Biotechnology Information Nucleotide database, identifying a point mutation which added a premature stop codon within the first 20 codons of the target gene in 93.2% of all tested gene-overprinted gene pairs. This shows that Pyviko can be used successfully in a wide variety of contexts to facilitate the molecular cloning and study of viral overprinted genes. Pyviko is an extensible and intuitive Python tool for designing knockouts of overlapping genes. Freely available as both a Python package and a web-based interface ( http://louiejtaylor.github.io/pyViKO/ ), Pyviko simplifies the experimental design of gene knockouts in complex viruses with overlapping genes.

14 CFR 437.85 - Allowable design changes; modification of an experimental permit.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Conditions of an Experimental Permit § 437.85 Allowable design changes; modification of an experimental... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Allowable design changes; modification of an experimental permit. 437.85 Section 437.85 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION...

14 CFR 437.85 - Allowable design changes; modification of an experimental permit.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Conditions of an Experimental Permit § 437.85 Allowable design changes; modification of an experimental... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Allowable design changes; modification of an experimental permit. 437.85 Section 437.85 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION...

14 CFR 437.85 - Allowable design changes; modification of an experimental permit.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Conditions of an Experimental Permit § 437.85 Allowable design changes; modification of an experimental... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Allowable design changes; modification of an experimental permit. 437.85 Section 437.85 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION...

14 CFR 437.85 - Allowable design changes; modification of an experimental permit.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Conditions of an Experimental Permit § 437.85 Allowable design changes; modification of an experimental... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Allowable design changes; modification of an experimental permit. 437.85 Section 437.85 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION...

14 CFR 437.85 - Allowable design changes; modification of an experimental permit.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Conditions of an Experimental Permit § 437.85 Allowable design changes; modification of an experimental... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Allowable design changes; modification of an experimental permit. 437.85 Section 437.85 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION...

Critical considerations when planning experimental in vivo studies in dental traumatology.

PubMed

Andreasen, Jens O; Andersson, Lars

2011-08-01

In vivo studies are sometimes needed to understand healing processes after trauma. For several reasons, not the least ethical, such studies have to be carefully planned and important considerations have to be taken into account about suitability of the experimental model, sample size and optimizing the accuracy of the analysis. Several manuscripts of in vivo studies are submitted for publication to Dental Traumatology and rejected because of inadequate design, methodology or insufficient documentation of the results. The authors have substantial experience in experimental in vivo studies of tissue healing in dental traumatology and share their knowledge regarding critical considerations when planning experimental in vivo studies. © 2011 John Wiley & Sons A/S.

Self-tapping ability of carbon fibre reinforced polyetheretherketone suture anchors.

PubMed

Feerick, Emer M; Wilson, Joanne; Jarman-Smith, Marcus; Ó'Brádaigh, Conchur M; McGarry, J Patrick

2014-10-01

An experimental and computational investigation of the self-tapping ability of carbon fibre reinforced polyetheretherketone (CFR-PEEK) has been conducted. Six CFR-PEEK suture anchor designs were investigated using PEEK-OPTIMA® Reinforced, a medical grade of CFR-PEEK. Experimental tests were conducted to investigate the maximum axial force and torque required for self-taping insertion of each anchor design. Additional experimental tests were conducted for some anchor designs using pilot holes. Computational simulations were conducted to determine the maximum stress in each anchor design at various stages of insertion. Simulations also were performed to investigate the effect of wall thickness in the anchor head. The maximum axial force required to insert a self-tapping CFR-PEEK suture anchor did not exceed 150 N for any anchor design. The maximum torque required to insert a self-tapping CFR-PEEK suture anchor did not exceed 0.8 Nm. Computational simulations reveal significant stress concentrations in the region of the anchor tip, demonstrating that a re-design of the tip geometry should be performed to avoid fracture during self-tapping, as observed in the experimental component of this study. This study demonstrates the ability of PEEK-OPTIMA Reinforced suture anchors to self-tap polyurethane foam bone analogue. This provides motivation to further investigate the self-tapping ability of CFR-PEEK suture anchors in animal/cadaveric bone. An optimised design for CFR-PEEK suture anchors offers the advantages of radiolucency, and mechanical properties similar to bone with the ability to self-tap. This may have positive implications for reducing surgery times and the associated costs with the procedure. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

76 FR 76978 - Agency Information Collection Activities; Submission for Office of Management and Budget Review...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-09

... comparative visuals, and using vaguer language. This study is designed to apply the existing comparative... Effectiveness) studies designed to explore comparative effectiveness. When this large project is completed, FDA... Request; Experimental Study of Comparative Direct-to-Consumer Advertising AGENCY: Food and Drug...

Randomized Controlled Studies and Alternative Designs in Outcome Studies: Challenges and Opportunities

ERIC Educational Resources Information Center

Shadish, William R.

2011-01-01

This article reviews several decades of the author's meta-analytic and experimental research on the conditions under which nonrandomized experiments can approximate the results from randomized experiments (REs). Several studies make clear that we can expect accurate effect estimates from the regression discontinuity design, though its statistical…

Experimental Design for Stochastic Models of Nonlinear Signaling Pathways Using an Interval-Wise Linear Noise Approximation and State Estimation

PubMed Central

Zimmer, Christoph

2016-01-01

Background Computational modeling is a key technique for analyzing models in systems biology. There are well established methods for the estimation of the kinetic parameters in models of ordinary differential equations (ODE). Experimental design techniques aim at devising experiments that maximize the information encoded in the data. For ODE models there are well established approaches for experimental design and even software tools. However, data from single cell experiments on signaling pathways in systems biology often shows intrinsic stochastic effects prompting the development of specialized methods. While simulation methods have been developed for decades and parameter estimation has been targeted for the last years, only very few articles focus on experimental design for stochastic models. Methods The Fisher information matrix is the central measure for experimental design as it evaluates the information an experiment provides for parameter estimation. This article suggest an approach to calculate a Fisher information matrix for models containing intrinsic stochasticity and high nonlinearity. The approach makes use of a recently suggested multiple shooting for stochastic systems (MSS) objective function. The Fisher information matrix is calculated by evaluating pseudo data with the MSS technique. Results The performance of the approach is evaluated with simulation studies on an Immigration-Death, a Lotka-Volterra, and a Calcium oscillation model. The Calcium oscillation model is a particularly appropriate case study as it contains the challenges inherent to signaling pathways: high nonlinearity, intrinsic stochasticity, a qualitatively different behavior from an ODE solution, and partial observability. The computational speed of the MSS approach for the Fisher information matrix allows for an application in realistic size models. PMID:27583802

Experimental Design and Data Analysis Issues Contribute to Inconsistent Results of C-Bouton Changes in Amyotrophic Lateral Sclerosis.

PubMed

Dukkipati, S Shekar; Chihi, Aouatef; Wang, Yiwen; Elbasiouny, Sherif M

2017-01-01

The possible presence of pathological changes in cholinergic synaptic inputs [cholinergic boutons (C-boutons)] is a contentious topic within the ALS field. Conflicting data reported on this issue makes it difficult to assess the roles of these synaptic inputs in ALS. Our objective was to determine whether the reported changes are truly statistically and biologically significant and why replication is problematic. This is an urgent question, as C-boutons are an important regulator of spinal motoneuron excitability, and pathological changes in motoneuron excitability are present throughout disease progression. Using male mice of the SOD1-G93A high-expresser transgenic ( G93A ) mouse model of ALS, we examined C-boutons on spinal motoneurons. We performed histological analysis at high statistical power, which showed no difference in C-bouton size in G93A versus wild-type motoneurons throughout disease progression. In an attempt to examine the underlying reasons for our failure to replicate reported changes, we performed further histological analyses using several variations on experimental design and data analysis that were reported in the ALS literature. This analysis showed that factors related to experimental design, such as grouping unit, sampling strategy, and blinding status, potentially contribute to the discrepancy in published data on C-bouton size changes. Next, we systematically analyzed the impact of study design variability and potential bias on reported results from experimental and preclinical studies of ALS. Strikingly, we found that practices such as blinding and power analysis are not systematically reported in the ALS field. Protocols to standardize experimental design and minimize bias are thus critical to advancing the ALS field.

A Quasi-Experimental Control Group Design Study to Determine the Effect of Integrating Character Education into a High School Social Studies Curriculum through Storytelling

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…

Efficient experimental design and analysis strategies for the detection of differential expression using RNA-Sequencing

PubMed Central

2012-01-01

Background RNA sequencing (RNA-Seq) has emerged as a powerful approach for the detection of differential gene expression with both high-throughput and high resolution capabilities possible depending upon the experimental design chosen. Multiplex experimental designs are now readily available, these can be utilised to increase the numbers of samples or replicates profiled at the cost of decreased sequencing depth generated per sample. These strategies impact on the power of the approach to accurately identify differential expression. This study presents a detailed analysis of the power to detect differential expression in a range of scenarios including simulated null and differential expression distributions with varying numbers of biological or technical replicates, sequencing depths and analysis methods. Results Differential and non-differential expression datasets were simulated using a combination of negative binomial and exponential distributions derived from real RNA-Seq data. These datasets were used to evaluate the performance of three commonly used differential expression analysis algorithms and to quantify the changes in power with respect to true and false positive rates when simulating variations in sequencing depth, biological replication and multiplex experimental design choices. Conclusions This work quantitatively explores comparisons between contemporary analysis tools and experimental design choices for the detection of differential expression using RNA-Seq. We found that the DESeq algorithm performs more conservatively than edgeR and NBPSeq. With regard to testing of various experimental designs, this work strongly suggests that greater power is gained through the use of biological replicates relative to library (technical) replicates and sequencing depth. Strikingly, sequencing depth could be reduced as low as 15% without substantial impacts on false positive or true positive rates. PMID:22985019

Efficient experimental design and analysis strategies for the detection of differential expression using RNA-Sequencing.

PubMed

Robles, José A; Qureshi, Sumaira E; Stephen, Stuart J; Wilson, Susan R; Burden, Conrad J; Taylor, Jennifer M

2012-09-17

RNA sequencing (RNA-Seq) has emerged as a powerful approach for the detection of differential gene expression with both high-throughput and high resolution capabilities possible depending upon the experimental design chosen. Multiplex experimental designs are now readily available, these can be utilised to increase the numbers of samples or replicates profiled at the cost of decreased sequencing depth generated per sample. These strategies impact on the power of the approach to accurately identify differential expression. This study presents a detailed analysis of the power to detect differential expression in a range of scenarios including simulated null and differential expression distributions with varying numbers of biological or technical replicates, sequencing depths and analysis methods. Differential and non-differential expression datasets were simulated using a combination of negative binomial and exponential distributions derived from real RNA-Seq data. These datasets were used to evaluate the performance of three commonly used differential expression analysis algorithms and to quantify the changes in power with respect to true and false positive rates when simulating variations in sequencing depth, biological replication and multiplex experimental design choices. This work quantitatively explores comparisons between contemporary analysis tools and experimental design choices for the detection of differential expression using RNA-Seq. We found that the DESeq algorithm performs more conservatively than edgeR and NBPSeq. With regard to testing of various experimental designs, this work strongly suggests that greater power is gained through the use of biological replicates relative to library (technical) replicates and sequencing depth. Strikingly, sequencing depth could be reduced as low as 15% without substantial impacts on false positive or true positive rates.

Hand controller study of force and control mode

NASA Technical Reports Server (NTRS)

Morris, A. Terry

1992-01-01

The objectives are to compare and evaluate the utility and effectiveness of various input control devices, e.g., hand controllers, with respect to the relative importance of force and operation control mode (rate or position) for Space Station Freedom (SSF) related tasks. The topics are presented in viewgraph form and include the: Intelligent Research Systems Lab (ISRL) experimental design; Telerobotic Systems Research Laboratory (TSRL) final experimental design; and factor analysis summary of results.

Ultrafiltration membrane reactors for enzymatic resolution of amino acids: design model and optimization.

PubMed

Bódalo, A; Gómez, J L.; Gómez, E; Bastida, J; Máximo, M F.; Montiel, M C.

2001-03-08

In this paper the possibility of continuous resolution of DL-phenylalanine, catalyzed by L-aminoacylase in a ultrafiltration membrane reactor (UFMR) is presented. A simple design model, based on previous kinetic studies, has been demonstrated to be capable of describing the behavior of the experimental system. The model has been used to determine the optimal experimental conditions to carry out the asymmetrical hydrolysis of N-acetyl-DL-phenylalanine.

EXPERIMENTAL MOLTEN-SALT-FUELED 30-Mw POWER REACTOR

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

Alexander, L.G.; Kinyon, B.W.; Lackey, M.E.

1960-03-24

A preliminary design study was made of an experimental molten-salt- fueled power reactor. The reactor considered is a single-region homogeneous burner coupled with a Loeffler steam-generating cycle. Conceptual plant layouts, basic information on the major fuel circuit components, a process flowsheet, and the nuclear characteristics of the core are presented. The design plant electrical output is 10 Mw, and the total construction cost is estimated to be approximately ,000,000. (auth)

Influence of conformity on the wear of total knee replacement: An experimental study

PubMed Central

Brockett, Claire L; Carbone, Silvia; Fisher, John; Jennings, Louise M

2017-01-01

Wear of total knee replacement continues to be a significant factor influencing the clinical longevity of implants. Historically, failure due to delamination and fatigue directed design towards more conforming inserts to reduce contact stress. As new generations of more oxidatively stable polyethylene have been developed, more flexibility in bearing design has been introduced. The aim of this study was to investigate the effect of insert conformity on the wear performance of a fixed bearing total knee replacement through experimental simulation. Two geometries of insert were studied under standard gait conditions. There was a significant reduction in wear with reducing implant conformity. This study has demonstrated that bearing conformity has a significant impact on the wear performance of a fixed bearing total knee replacement, providing opportunities to improve clinical performance through enhanced material and design selection. PMID:29251167

PRACTICAL STRATEGIES FOR PROCESSING AND ANALYZING SPOTTED OLIGONUCLEOTIDE MICROARRAY DATA

EPA Science Inventory

Thoughtful data analysis is as important as experimental design, biological sample quality, and appropriate experimental procedures for making microarrays a useful supplement to traditional toxicology. In the present study, spotted oligonucleotide microarrays were used to profile...

Quiet Clean Short-Haul Experimental Engine (QSCEE). Preliminary analyses and design report, volume 1

NASA Technical Reports Server (NTRS)

1974-01-01

The experimental propulsion systems to be built and tested in the 'quiet, clean, short-haul experimental engine' program are presented. The flight propulsion systems are also presented. The following areas are discussed: acoustic design; emissions control; engine cycle and performance; fan aerodynamic design; variable-pitch actuation systems; fan rotor mechanical design; fan frame mechanical design; and reduction gear design.

An experimental search strategy retrieves more precise results than PubMed and Google for questions about medical interventions

PubMed Central

Dylla, Daniel P.; Megison, Susan D.

2015-01-01

Objective. We compared the precision of a search strategy designed specifically to retrieve randomized controlled trials (RCTs) and systematic reviews of RCTs with search strategies designed for broader purposes. Methods. We designed an experimental search strategy that automatically revised searches up to five times by using increasingly restrictive queries as long at least 50 citations were retrieved. We compared the ability of the experimental and alternative strategies to retrieve studies relevant to 312 test questions. The primary outcome, search precision, was defined for each strategy as the proportion of relevant, high quality citations among the first 50 citations retrieved. Results. The experimental strategy had the highest median precision (5.5%; interquartile range [IQR]: 0%–12%) followed by the narrow strategy of the PubMed Clinical Queries (4.0%; IQR: 0%–10%). The experimental strategy found the most high quality citations (median 2; IQR: 0–6) and was the strategy most likely to find at least one high quality citation (73% of searches; 95% confidence interval 68%–78%). All comparisons were statistically significant. Conclusions. The experimental strategy performed the best in all outcomes although all strategies had low precision. PMID:25922798

Investigation of the feasibility of optical diagnostic measurements at the exit of the SSME

NASA Technical Reports Server (NTRS)

Shirley, John A.; Boedeker, Laurence R.

1993-01-01

Under Contract NAS8-36861 sponsored by NASA Marshall Space Flight Center, the United Technologies Research Center is conducting an investigation of the feasibility of remote optical diagnostics to measure temperature, species concentration and velocity at the exit of the Space Shuttle Main Engine (SSME). This is a two phase study consisting of a conceptual design phase followed by a laboratory experimental investigation. The first task of the conceptual design studies is to screen and evaluate the techniques which can be used for the measurements. The second task is to select the most promising technique or techniques, if as expected, more than one type of measurement must be used to measure all the flow variables of interest. The third task is to examine in detail analytically the capabilities and limitations of the selected technique(s). The results of this study are described in the section of this report entitled Conceptual Design Investigations. The conceptual design studies identified spontaneous Raman scattering and photodissociative flow-tagging for measurements respectively of gas temperature and major species concentration and for velocity. These techniques and others that were considered are described in the section describing the conceptual design. The objective of the second phase of investigations was to investigate experimentally the techniques identified in the first phase. The first task of the experimental feasibility study is to design and assemble laboratory scale experimental apparatus to evaluate the best approaches for SSME exit optical diagnostics for temperature, species concentrations and velocity, as selected in the Phase I conceptual design study. The second task is to evaluate performance, investigate limitations, and establish actual diagnostic capabilities, accuracies and precision for the selected optical systems. The third task is to evaluate design requirements and system trade-offs of conceptual instruments. Spontaneous Raman scattering excited by a KrF excimer laser pulse was investigated for SSME exit plane temperature and major species concentration measurements. The relative concentrations of molecular hydrogen and water vapor would be determined by measuring the integrated Q-branch scattering signals through narrow bandpass filters in front of photomultipliers. The temperature would be determined by comparing the signal from a single hydrogen rotational Raman line to the total hydrogen Q-branch signal. The rotational Raman line would be isolated by a monochromator and detected with a PMT.

Quality Appraisal of Single-Subject Experimental Designs: An Overview and Comparison of Different Appraisal Tools

ERIC Educational Resources Information Center

Wendt, Oliver; Miller, Bridget

2012-01-01

Critical appraisal of the research literature is an essential step in informing and implementing evidence-based practice. Quality appraisal tools that assess the methodological quality of experimental studies provide a means to identify the most rigorous research suitable for evidence-based decision-making. In single-subject experimental research,…

Experimental Analysis of a Four-Component Procedure for Decreasing Noncompliance in a Preschool Child.

ERIC Educational Resources Information Center

Miller, Regina M.; And Others

In this study a 4-component procedure designed to decrease a 4-year-old child's noncompliance behaviors was experimentally analyzed as to the effectiveness of the separate components of the package. Once experimental control had been demonstrated and the subject's noncompliance behaviors had been decreased to an acceptable level, separate analyses…

Ranking factors affecting emissions of GHG from incubated agricultural soils.

PubMed

García-Marco, S; Ravella, S R; Chadwick, D; Vallejo, A; Gregory, A S; Cárdenas, L M

2014-07-01

Agriculture significantly contributes to global greenhouse gas (GHG) emissions and there is a need to develop effective mitigation strategies. The efficacy of methods to reduce GHG fluxes from agricultural soils can be affected by a range of interacting management and environmental factors. Uniquely, we used the Taguchi experimental design methodology to rank the relative importance of six factors known to affect the emission of GHG from soil: nitrate (NO 3 - ) addition, carbon quality (labile and non-labile C), soil temperature, water-filled pore space (WFPS) and extent of soil compaction. Grassland soil was incubated in jars where selected factors, considered at two or three amounts within the experimental range, were combined in an orthogonal array to determine the importance and interactions between factors with a L 16 design, comprising 16 experimental units. Within this L 16 design, 216 combinations of the full factorial experimental design were represented. Headspace nitrous oxide (N 2 O), methane (CH 4 ) and carbon dioxide (CO 2 ) concentrations were measured and used to calculate fluxes. Results found for the relative influence of factors (WFPS and NO 3 - addition were the main factors affecting N 2 O fluxes, whilst glucose, NO 3 - and soil temperature were the main factors affecting CO 2 and CH 4 fluxes) were consistent with those already well documented. Interactions between factors were also studied and results showed that factors with little individual influence became more influential in combination. The proposed methodology offers new possibilities for GHG researchers to study interactions between influential factors and address the optimized sets of conditions to reduce GHG emissions in agro-ecosystems, while reducing the number of experimental units required compared with conventional experimental procedures that adjust one variable at a time.

Ranking factors affecting emissions of GHG from incubated agricultural soils

PubMed Central

García-Marco, S; Ravella, S R; Chadwick, D; Vallejo, A; Gregory, A S; Cárdenas, L M

2014-01-01

Agriculture significantly contributes to global greenhouse gas (GHG) emissions and there is a need to develop effective mitigation strategies. The efficacy of methods to reduce GHG fluxes from agricultural soils can be affected by a range of interacting management and environmental factors. Uniquely, we used the Taguchi experimental design methodology to rank the relative importance of six factors known to affect the emission of GHG from soil: nitrate (NO3−) addition, carbon quality (labile and non-labile C), soil temperature, water-filled pore space (WFPS) and extent of soil compaction. Grassland soil was incubated in jars where selected factors, considered at two or three amounts within the experimental range, were combined in an orthogonal array to determine the importance and interactions between factors with a L16 design, comprising 16 experimental units. Within this L16 design, 216 combinations of the full factorial experimental design were represented. Headspace nitrous oxide (N2O), methane (CH4) and carbon dioxide (CO2) concentrations were measured and used to calculate fluxes. Results found for the relative influence of factors (WFPS and NO3− addition were the main factors affecting N2O fluxes, whilst glucose, NO3− and soil temperature were the main factors affecting CO2 and CH4 fluxes) were consistent with those already well documented. Interactions between factors were also studied and results showed that factors with little individual influence became more influential in combination. The proposed methodology offers new possibilities for GHG researchers to study interactions between influential factors and address the optimized sets of conditions to reduce GHG emissions in agro-ecosystems, while reducing the number of experimental units required compared with conventional experimental procedures that adjust one variable at a time. PMID:25177207

The effects of a technology-enhanced inquiry instructional model on students' understanding of science in Thailand

NASA Astrophysics Data System (ADS)

Lertwanasiriwan, Chaiwuti

The study examined the effects of a technology-enhanced inquiry instructional model on students' understanding of science in Thailand. A mixed quantitative research design was selected for the research design. A pretest-posttest control-group design was implemented for the experimental research. A causal-comparative design using questionnaire and classroom observation was employed for the non-experimental research. Two sixth-grade classrooms at a medium-sized public school in Bangkok, Thailand were randomly selected for the study - one as the control group and the other as the experimental group. The 34 students in the control group only received the inquiry instructional model, while the 35 students in the experimental group received the technology-enhanced inquiry instructional model. Both groups of students had been taught by the same science teacher for 15 weeks (three periods per week). The results and findings from the study seemed to indicate that both the technology-enhanced inquiry instructional model and the inquiry instructional model significantly improve students' understanding of science. However, it might be claimed that students receiving the technology-enhanced inquiry instructional model gain more than students only receiving the inquiry instructional model. In addition, the technology-enhanced inquiry instructional model seemed to support the assessment during the 5E Model's evaluation stage. Most students appeared to have very good attitudes toward using it in the science classroom suggesting that the technology-enhanced inquiry instructional model motivates students to learn science.

Effect of experimental design on the prediction performance of calibration models based on near-infrared spectroscopy for pharmaceutical applications.

PubMed

Bondi, Robert W; Igne, Benoît; Drennen, James K; Anderson, Carl A

2012-12-01

Near-infrared spectroscopy (NIRS) is a valuable tool in the pharmaceutical industry, presenting opportunities for online analyses to achieve real-time assessment of intermediates and finished dosage forms. The purpose of this work was to investigate the effect of experimental designs on prediction performance of quantitative models based on NIRS using a five-component formulation as a model system. The following experimental designs were evaluated: five-level, full factorial (5-L FF); three-level, full factorial (3-L FF); central composite; I-optimal; and D-optimal. The factors for all designs were acetaminophen content and the ratio of microcrystalline cellulose to lactose monohydrate. Other constituents included croscarmellose sodium and magnesium stearate (content remained constant). Partial least squares-based models were generated using data from individual experimental designs that related acetaminophen content to spectral data. The effect of each experimental design was evaluated by determining the statistical significance of the difference in bias and standard error of the prediction for that model's prediction performance. The calibration model derived from the I-optimal design had similar prediction performance as did the model derived from the 5-L FF design, despite containing 16 fewer design points. It also outperformed all other models estimated from designs with similar or fewer numbers of samples. This suggested that experimental-design selection for calibration-model development is critical, and optimum performance can be achieved with efficient experimental designs (i.e., optimal designs).

Recommendations for research design of telehealth studies.

PubMed

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.

Study of power-to-weight ratio of the electrothermal propulsion system of nanosatellite maneuvering satellite platform

NASA Astrophysics Data System (ADS)

Blinov, V. N.; Vavilov, I. S.; Kositsin, V. V.; Lukyanchik, A. I.; Ruban, V. I.; Shalay, V. V.

2018-01-01

The direction of the solution of the actual task of maneuvering satellite platforms (MSP) design for nanosatellite weighing up to 10 kg, power-to-weight ratio of PS up to 8 W (electrothermal micro engine (ETME) 5 W, vaporizer 2 W, electrovalve up to 1 W) and with characteristic velocity up to 60 m/s were considered on the basis of studies of the propulsion system(PS) with ETME. The aim of study is the confirmation of technical possibility of nanosatellites design with mass up to 10 kg, power-to-weight ratio up to 8 W and with characteristic velocity up to 60 m/s on the basis of PS prototype experimental studies. In the course of the research tasks were solved to determine the design of PS and ETME of nanosatellit’s MSP, determine the electric parameters of PS depending on power consumption that determining specific impulse of ETME, and estimate the implemented characteristic velocity of the nanosatellite. The PS constructive scheme of nanosatellite mass of 10 kg was design, PS experimental prototype was produced and PS experimental research on ammonia were conducted. The 200°C was reached per 900 s at 5 W ETME power consumption with nitrogen, that equivalent to specific impulse of ammonia ETME 124/136 s when entering the stationary mode. 2 W energy consumption of a two-thread liquid ammonia vaporizer is experimentally substantiated. The using of electrovelve stepped control cyclogram allowed to reduce the average power consumption to 1 W.

Parametric study of the swimming performance of a fish robot propelled by a flexible caudal fin.

PubMed

Low, K H; Chong, C W

2010-12-01

In this paper, we aim to study the swimming performance of fish robots by using a statistical approach. A fish robot employing a carangiform swimming mode had been used as an experimental platform for the performance study. The experiments conducted aim to investigate the effect of various design parameters on the thrust capability of the fish robot with a flexible caudal fin. The controllable parameters associated with the fin include frequency, amplitude of oscillation, aspect ratio and the rigidity of the caudal fin. The significance of these parameters was determined in the first set of experiments by using a statistical approach. A more detailed parametric experimental study was then conducted with only those significant parameters. As a result, the parametric study could be completed with a reduced number of experiments and time spent. With the obtained experimental result, we were able to understand the relationship between various parameters and a possible adjustment of parameters to obtain a higher thrust. The proposed statistical method for experimentation provides an objective and thorough analysis of the effects of individual or combinations of parameters on the swimming performance. Such an efficient experimental design helps to optimize the process and determine factors that influence variability.

Effect of systematic menstrual health education on dysmenorrheic female adolescents' knowledge, attitudes, and self-care behavior.

PubMed

Chiou, Miin-Huey; Wang, Hsiu-Hung; Yang, Yi-Hsin

2007-04-01

The purpose of this study was to evaluate the effects of systematic health education on female adolescents' knowledge of dysmenorrhea, menstrual attitudes, and dysmenorrhea-related self-care behaviors. Through the research process, a dysmenorrheal self-care pamphlet for female adolescents was developed. The study used a quasi-experimental intervention with a nonequivalent-control group design. Three vocational nursing schools were requested to participate in this study: one was assigned to the experimental group and two were assigned to the control group. Female students who had experienced dysmenorrheic cramps two or more times during the last 6 months since the interview were recruited for the study. There were 218 subjects randomly assigned to an experimental group, and 237 subjects to a control group. Intervention consisted of a three-session health education program in which the experimental group was split up into six smaller groups. Data were collected before, 2 weeks after, and 4 months after the intervention. Results revealed a significant increase in the experimental group members' dysmenorrhea-related knowledge and self-care behavior, but not in their attitudes. The findings of this study can serve as a guide to healthcare providers who want to design an effective systematic menstrual health education program for female adolescents.

Quasi-experimental study designs series-paper 10: synthesizing evidence for effects collected from quasi-experimental studies presents surmountable challenges.

PubMed

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.

A Structured Career Intervention Program for Academically Challenged Students

ERIC Educational Resources Information Center

Salleh, Amla; Abdullah, Syed Mohamad; Mahmud, Zuria; Ghavifekr, Simin; Ishak, Noriah

2013-01-01

A study was carried out to test the effects of a 2-week structured intervention program on academically challenged students' career development. A quasi-experimental study was designed using pre-tests, post-tests, and a control group approach to examine the effects of the intervention program. Data were collected from both the experimental and…

Replicating Experimental Impact Estimates Using a Regression Discontinuity Approach. NCEE 2012-4025

ERIC Educational Resources Information Center

Gleason, Philip M.; Resch, Alexandra M.; Berk, Jillian A.

2012-01-01

This NCEE Technical Methods Paper compares the estimated impacts of an educational intervention using experimental and regression discontinuity (RD) study designs. The analysis used data from two large-scale randomized controlled trials--the Education Technology Evaluation and the Teach for America Study--to provide evidence on the performance of…

Implementation of Cooperative Learning Model in Preschool

ERIC Educational Resources Information Center

Akçay, Nilüfer Okur

2016-01-01

In this study, the effectivity of jigsaw method, one of the cooperative learning models, on teaching the concepts related to sense organs and their functions to four-five year-old children in nursery class was analyzed. The study is in the semi-experimental design consisting of experimental and control groups and pretest and posttest. The sample…

Strategies Training in the Teaching of Reading Comprehension for EFL Learners in Indonesia

ERIC Educational Resources Information Center

Mistar, Junaidi; Zuhairi, Alfan; Yanti, Nofita

2016-01-01

This study investigated the effect of reading strategies training on the students' literal and inferential reading comprehension. The training involved three concrete strategies: predicting, text mapping, and summarizing. To achieve the purpose of this study, a quasi experimental design was selected with the experimental group being given reading…

Problem-Based Learning in the English Language Classroom

ERIC Educational Resources Information Center

Othman, Normala; Shah, Mohamed Ismail Ahamad

2013-01-01

The purpose of this study was to investigate the effects of the problem-based learning approach (PBL) on students in language classes in two areas: course content and language development. The study was conducted on 128 students, grouped into the experimental and control groups, and employed an experimental research design. The syllabus, textbook,…

Studying technology use as social practice: the untapped potential of ethnography

PubMed Central

2011-01-01

Information and communications technologies (ICTs) in healthcare are often introduced with expectations of higher-quality, more efficient, and safer care. Many fail to meet these expectations. We argue here that the well-documented failures of ICTs in healthcare are partly attributable to the philosophical foundations of much health informatics research. Positivistic assumptions underpinning the design, implementation and evaluation of ICTs (in particular the notion that technology X has an impact which can be measured and reproduced in new settings), and the deterministic experimental and quasi-experimental study designs which follow from these assumptions, have inherent limitations when ICTs are part of complex social practices involving multiple human actors. We suggest that while experimental and quasi-experimental studies have an important place in health informatics research overall, ethnography is the preferred methodological approach for studying ICTs introduced into complex social systems. But for ethnographic approaches to be accepted and used to their full potential, many in the health informatics community will need to revisit their philosophical assumptions about what counts as research rigor. PMID:21521535

A framework for self-experimentation in personalized health.

PubMed

Karkar, Ravi; Zia, Jasmine; Vilardaga, Roger; Mishra, Sonali R; Fogarty, James; Munson, Sean A; Kientz, Julie A

2016-05-01

To describe an interdisciplinary and methodological framework for applying single case study designs to self-experimentation in personalized health. The authors examine the framework's applicability to various health conditions and present an initial case study with irritable bowel syndrome (IBS). An in-depth literature review was performed to develop the framework and to identify absolute and desired health condition requirements for the application of this framework. The authors developed mobile application prototypes, storyboards, and process flows of the framework using IBS as the case study. The authors conducted three focus groups and an online survey using a human-centered design approach for assessing the framework's feasibility. All 6 focus group participants had a positive view about our framework and volunteered to participate in future studies. Most stated they would trust the results because it was their own data being analyzed. They were most concerned about confounds, nonmeaningful measures, and erroneous assumptions on the timing of trigger effects. Survey respondents (N = 60) were more likely to be adherent to an 8- vs 12-day study length even if it meant lower confidence results. Implementation of the self-experimentation framework in a mobile application appears to be feasible for people with IBS. This framework can likely be applied to other health conditions. Considerations include the learning curve for teaching self-experimentation to non-experts and the challenges involved in operationalizing and customizing study designs. Using mobile technology to guide people through self-experimentation to investigate health questions is a feasible and promising approach to advancing personalized health. © The Author 2015. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

76 FR 32148 - Applications for New Awards; Investing in Innovation Fund

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-03

.... Interrupted time series design \\5\\ means a type of quasi- experimental study in which the outcome of interest... interrupted time series design that relies on the comparison of treatment effects on a single subject or group... matched comparison group designs (as defined in this notice), interrupted time series designs (as defined...

75 FR 7573 - Office of Safe and Drug-Free Schools; Overview Information; Models of Exemplary, Effective, and...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-22

... to the research, then a quasi- experimental evaluation of the program's implementation on the... experimental or quasi- experimental research design, with the evaluation results suggesting effectiveness in... this grant competition, a research design of the highest quality means an experimental design in which...

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…

Computational Design of a Krueger Flap Targeting Conventional Slat Aerodynamics

NASA Technical Reports Server (NTRS)

Akaydin, H. Dogus; Housman, Jeffrey A.; Kiris, Cetin C.; Bahr, Christopher J.; Hutcheson, Florence V.

2016-01-01

In this study, we demonstrate the design of a Krueger flap as a substitute for a conventional slat in a high-lift system. This notional design, with the objective of matching equivalent-mission performance on aircraft approach, was required for a comparative aeroacoustic study with computational and experimental components. We generated a family of high-lift systems with Krueger flaps based on a set of design parameters. Then, we evaluated the high-lift systems using steady 2D RANS simulations to find a good match for the conventional slat, based on total lift coefficients in free-air. Finally, we evaluated the mean aerodynamics of the high-lift systems with Krueger flap and conventional slat as they were installed in an open-jet wind tunnel flow. The surface pressures predicted with the simulations agreed well with experimental results.

Quasi-experimental study designs series-paper 6: risk of bias assessment.

PubMed

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.

Are There Scenarios When the Use of Non-Placebo-Control Groups in Experimental Trial Designs Increase Expected Value to Society?

PubMed

Uyei, Jennifer; Braithwaite, R Scott

2016-01-01

Despite the benefits of the placebo-controlled trial design, it is limited by its inability to quantify total benefits and harms. Such trials, for example, are not designed to detect an intervention's placebo or nocebo effects, which if detected could alter the benefit-to-harm balance and change a decision to adopt or reject an intervention. In this article, we explore scenarios in which alternative experimental trial designs, which differ in the type of control used, influence expected value across a range of pretest assumptions and study sample sizes. We developed a decision model to compare 3 trial designs and their implications for decision making: 2-arm placebo-controlled trial ("placebo-control"), 2-arm intervention v. do nothing trial ("null-control"), and an innovative 3-arm trial design: intervention v. do nothing v. placebo trial ("novel design"). Four scenarios were explored regarding particular attributes of a hypothetical intervention: 1) all benefits and no harm, 2) no biological effect, 3) only biological effects, and 4) surreptitious harm (no biological benefit or nocebo effect). Scenario 1: When sample sizes were very small, the null-control was preferred, but as sample sizes increased, expected value of all 3 designs converged. Scenario 2: The null-control was preferred regardless of sample size when the ratio of placebo to nocebo effect was >1; otherwise, the placebo-control was preferred. Scenario 3: When sample size was very small, the placebo-control was preferred when benefits outweighed harms, but the novel design was preferred when harms outweighed benefits. Scenario 4: The placebo-control was preferred when harms outweighed placebo benefits; otherwise, preference went to the null-control. Scenarios are hypothetical, study designs have not been tested in a real-world setting, blinding is not possible in all designs, and some may argue the novel design poses ethical concerns. We identified scenarios in which alternative experimental study designs would confer greater expected value than the placebo-controlled trial design. The likelihood and prevalence of such situations warrant further study. © The Author(s) 2015.

An investigation of the effects of relevant samples and a comparison of verification versus discovery based lab design

NASA Astrophysics Data System (ADS)

Rieben, James C., Jr.

This study focuses on the effects of relevance and lab design on student learning within the chemistry laboratory environment. A general chemistry conductivity of solutions experiment and an upper level organic chemistry cellulose regeneration experiment were employed. In the conductivity experiment, the two main variables studied were the effect of relevant (or "real world") samples on student learning and a verification-based lab design versus a discovery-based lab design. With the cellulose regeneration experiment, the effect of a discovery-based lab design vs. a verification-based lab design was the sole focus. Evaluation surveys consisting of six questions were used at three different times to assess student knowledge of experimental concepts. In the general chemistry laboratory portion of this study, four experimental variants were employed to investigate the effect of relevance and lab design on student learning. These variants consisted of a traditional (or verification) lab design, a traditional lab design using "real world" samples, a new lab design employing real world samples/situations using unknown samples, and the new lab design using real world samples/situations that were known to the student. Data used in this analysis were collected during the Fall 08, Winter 09, and Fall 09 terms. For the second part of this study a cellulose regeneration experiment was employed to investigate the effects of lab design. A demonstration creating regenerated cellulose "rayon" was modified and converted to an efficient and low-waste experiment. In the first variant students tested their products and verified a list of physical properties. In the second variant, students filled in a blank physical property chart with their own experimental results for the physical properties. Results from the conductivity experiment show significant student learning of the effects of concentration on conductivity and how to use conductivity to differentiate solution types with the use of real world samples. In the organic chemistry experiment, results suggest that the discovery-based design improved student retention of the chain length differentiation by physical properties relative to the verification-based design.

When Theater Comes to Engineering Design: Oh How Creative They Can Be.

PubMed

Pfeiffer, Ferris M; Bauer, Rachel E; Borgelt, Steve; Burgoyne, Suzanne; Grant, Sheila; Hunt, Heather K; Pardoe, Jennie J; Schmidt, David C

2017-07-01

The creative process is fun, complex, and sometimes frustrating, but it is critical to the future of our nation and progress in science, technology, engineering, mathematics (STEM), as well as other fields. Thus, we set out to see if implementing methods of active learning typical to the theater department could impact the creativity of senior capstone design students in the bioengineering (BE) department. Senior bioengineering capstone design students were allowed to self-select into groups. Prior to the beginning of coursework, all students completed a validated survey measuring engineering design self-efficacy. The control and experimental groups both received standard instruction, but in addition the experimental group received 1 h per week of creativity training developed by a theater professor. Following the semester, the students again completed the self-efficacy survey. The surveys were examined to identify differences in the initial and final self-efficacy in the experimental and control groups over the course of the semester. An analysis of variance was used to compare the experimental and control groups with p < 0.05 considered significant. Students in the experimental group reported more than a twofold (4.8 (C) versus 10.9 (E)) increase of confidence. Additionally, students in the experimental group were more motivated and less anxious when engaging in engineering design following the semester of creativity instruction. The results of this pilot study indicate that there is a significant potential to improve engineering students' creative self-efficacy through the implementation of a "curriculum of creativity" which is developed using theater methods.

Designing a mixture experiment when the components are subject to a nonlinear multiple-component constraint

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

Piepel, Greg F.; Cooley, Scott K.; Vienna, John D.

This article presents a case study of developing an experimental design for a constrained mixture experiment when the experimental region is defined by single-component constraints (SCCs), linear multiple-component constraints (MCCs), and a nonlinear MCC. Traditional methods and software for designing constrained mixture experiments with SCCs and linear MCCs are not directly applicable because of the nonlinear MCC. A modification of existing methodology to account for the nonlinear MCC was developed and is described in this article. The case study involves a 15-component nuclear waste glass example in which SO3 is one of the components. SO3 has a solubility limit inmore » glass that depends on the composition of the balance of the glass. A goal was to design the experiment so that SO3 would not exceed its predicted solubility limit for any of the experimental glasses. The SO3 solubility limit had previously been modeled by a partial quadratic mixture (PQM) model expressed in the relative proportions of the 14 other components. The PQM model was used to construct a nonlinear MCC in terms of all 15 components. In addition, there were SCCs and linear MCCs. This article discusses the waste glass example and 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.« less

Feasibility study of a cosmetic cream added with aqueous extract and oil from date (Phoenix dactylifera L.) fruit seed using experimental design.

PubMed

Lecheb, Fatma; Benamara, Salem

2015-01-01

This article reports on the feasibility study of a cosmetic cream added with aqueous extract and oil from date (Phoenix dactylifera L.) fruit seed using experimental design. First, the mixture design was applied to optimize the cosmetic formula. The responses (dependent variables) were the spreadability (YSp) and viscosity (YVis), the factors (independent variables) being the weight proportions of the fatty phase (X1), the aqueous date seed extract (X2), and the beeswax (X3). Second, the cosmetic stability study was conducted by applying a full factorial design. Here, three responses were considered [spreadability (Sp), viscosity (Vis), and peroxide index (PI)], the independent variables being the concentration of the date seed oil (DSO) (x1), storage temperature (x2), and storage time (x3). Results showed that in the case of mixture design, the second-order polynomial equations correctly described experimental data. Globally, results show that there is a relatively wide composition range to ensure a suitable cosmetic cream from the point of view of Sp and Vis. Regarding the cosmetic stability, the storage time was found to be the most influential factor on both Vis and PI, which are considered here as indicators of physical and chemical stability of the emulsion, respectively. Finally, the elaborated and commercial cosmetics were compared in terms of pH, Sp, and centrifugation test (Ct).

Factorial Experiments: Efficient Tools for Evaluation of Intervention Components

PubMed Central

Collins, Linda M.; Dziak, John J.; Kugler, Kari C.; Trail, Jessica B.

2014-01-01

Background An understanding of the individual and combined effects of a set of intervention components is important for moving the science of preventive medicine interventions forward. This understanding can often be achieved in an efficient and economical way via a factorial experiment, in which two or more independent variables are manipulated. The factorial experiment is a complement to the randomized controlled trial (RCT); the two designs address different research questions. Purpose This article offers an introduction to factorial experiments aimed at investigators trained primarily in the RCT. Method The factorial experiment is compared and contrasted with other experimental designs used commonly in intervention science to highlight where each is most efficient and appropriate. Results Several points are made: factorial experiments make very efficient use of experimental subjects when the data are properly analyzed; a factorial experiment can have excellent statistical power even if it has relatively few subjects per experimental condition; and when conducting research to select components for inclusion in a multicomponent intervention, interactions should be studied rather than avoided. Conclusions Investigators in preventive medicine and related areas should begin considering factorial experiments alongside other approaches. Experimental designs should be chosen from a resource management perspective, which states that the best experimental design is the one that provides the greatest scientific benefit without exceeding available resources. PMID:25092122

Design and construction of Keda Space Plasma Experiment (KSPEX) for the investigation of the boundary layer processes of ionospheric depletions.

PubMed

Liu, Yu; Zhang, Zhongkai; Lei, Jiuhou; Cao, Jinxiang; Yu, Pengcheng; Zhang, Xiao; Xu, Liang; Zhao, Yaodong

2016-09-01

In this work, the design and construction of the Keda Space Plasma EXperiment (KSPEX), which aims to study the boundary layer processes of ionospheric depletions, are described in detail. The device is composed of three stainless-steel sections: two source chambers at both ends and an experimental chamber in the center. KSPEX is a steady state experimental device, in which hot filament arrays are used to produce plasmas in the two sources. A Macor-mesh design is adopted to adjust the plasma density and potential difference between the two plasmas, which creates a boundary layer with a controllable electron density gradient and inhomogeneous radial electric field. In addition, attachment chemicals can be released into the plasmas through a tailor-made needle valve which leads to the generation of negative ions plasmas. Ionospheric depletions can be modeled and simulated using KSPEX, and many micro-physical processes of the formation and evolution of an ionospheric depletion can be experimentally studied.

Electrochemical production and use of free chlorine for pollutant removal: an experimental design approach.

PubMed

Antonelli, Raissa; de Araújo, Karla Santos; Pires, Ricardo Francisco; Fornazari, Ana Luiza de Toledo; Granato, Ana Claudia; Malpass, Geoffroy Roger Pointer

2017-10-28

The present paper presents the study of (1) the optimization of electrochemical-free chlorine production using an experimental design approach, and (2) the application of the optimum conditions obtained for the application in photo-assisted electrochemical degradation of simulated textile effluent. In the experimental design the influence of inter-electrode gap, pH, NaCl concentration and current was considered. It was observed that the four variables studied are significant for the process, with NaCl concentration and current being the most significant variables for free chlorine production. The maximum free chlorine production was obtained at a current of 2.33 A and NaCl concentrations in 0.96 mol dm -3 . The application of the optimized conditions with simultaneous UV irradiation resulted in up to 83.1% Total Organic Carbon removal and 100% of colour removal over 180 min of electrolysis. The results indicate that a systematic (statistical) approach to the electrochemical treatment of pollutants can save time and reagents.

Development of a fast, lean and agile direct pelletization process using experimental design techniques.

PubMed

Politis, Stavros N; Rekkas, Dimitrios M

2017-04-01

A novel hot melt direct pelletization method was developed, characterized and optimized, using statistical thinking and experimental design tools. Mixtures of carnauba wax (CW) and HPMC K100M were spheronized using melted gelucire 50-13 as a binding material (BM). Experimentation was performed sequentially; a fractional factorial design was set up initially to screen the factors affecting the process, namely spray rate, quantity of BM, rotor speed, type of rotor disk, lubricant-glidant presence, additional spheronization time, powder feeding rate and quantity. From the eight factors assessed, three were further studied during process optimization (spray rate, quantity of BM and powder feeding rate), at different ratios of the solid mixture of CW and HPMC K100M. The study demonstrated that the novel hot melt process is fast, efficient, reproducible and predictable. Therefore, it can be adopted in a lean and agile manufacturing setting for the production of flexible pellet dosage forms with various release rates easily customized between immediate and modified delivery.

Advancing Scientific Reasoning in Upper Elementary Classrooms: Direct Instruction Versus Task Structuring

NASA Astrophysics Data System (ADS)

Lazonder, Ard W.; Wiskerke-Drost, Sjanou

2015-02-01

Several studies found that direct instruction and task structuring can effectively promote children's ability to design unconfounded experiments. The present study examined whether the impact of these interventions extends to other scientific reasoning skills by comparing the inquiry activities of 55 fifth-graders randomly assigned to one of three conditions. Children in the control condition investigated a four-variable inquiry task without additional support. Performance of this task in the direct instruction condition was preceded by a short training in experimental design, whereas children in the task structuring condition, who did not receive the introductory training, were given a version of the task that addressed the four variables one at a time. Analysis of children's experimentation behavior confirmed that direct instruction and task structuring are equally effective and superior to unguided inquiry. Both interventions also evoked more determinate predictions and valid inferences. These findings demonstrate that the effect of short-term interventions designed to promote unconfounded experimentation extends beyond the control of variables.

Shielding design of an underground experimental area at point 5 of the CERN Super Proton Synchrotron (SPS).

PubMed

Mueller, Mario J; Stevenson, Graham R

2005-01-01

Increasing projected values of the circulating beam intensity in the Super Proton Synchrotron (SPS) and decreasing limits to radiation exposure, taken with the increasing non-acceptance of unjustified and unoptimised radiation exposures, have led to the need to re-assess the shielding between the ECX and ECA5 underground experimental areas of the SPS. Twenty years ago, these experimental areas at SPS-Point 5 housed the UA1 experiment, where Carlo Rubbia and his team verified the existence of W and Z bosons. The study reported here describes such a re-assessment based on simulations using the multi-purpose FLUKA radiation transport code. This study concludes that while the main shield which is made of concrete blocks and is 4.8 m thick satisfactorily meets the current design limits even at the highest intensities presently planned for the SPS, dose rates calculated for liaison areas on both sides of the main shield significantly exceed the design limits. Possible ways of improving the shielding situation are discussed.

A minimal-contact intervention for cardiac inpatients: long-term effects on smoking cessation.

PubMed

Bolman, Catherine; de Vries, Hein; van Breukelen, Gerard

2002-08-01

This study examined the 1-year effects of a minimal-contact smoking cessation intervention for cardiac inpatients. The multicenter study included cardiac inpatients who had smoked prior to hospitalization. A pretest-posttest quasi-experimental design was used. Patients' experimental condition depended on the hospital they were assigned to. The design was partially randomized: 4 of the 11 hospitals selected the experimental condition themselves (2 experimental, 2 control), while the remaining 7 hospitals were randomly assigned. The experimental group consisted of patients of 5 hospitals (N = 388). Patients of 6 other hospitals served as the control group (N = 401). The intervention included stop-smoking advice by the cardiologist, brief counseling by the nurse, the provision of self-help materials, and aftercare by the cardiologist. Logistic regression analyses controlling for baseline differences and covariates did not show significant intervention effects on point prevalence and continuous abstinence. The study also showed that the outcomes were not significantly related to the way hospitals were assigned to the experimental condition. While short-term effects were found, the minimal-contact intervention did not result in significant effects after 12 months, at least if patients lost to follow-up were treated as posttest smokers. Efforts should be made to improve the intervention, especially the aftercare.

Experimental validation of an integrated controls-structures design methodology for a class of flexible space structures

NASA Technical Reports Server (NTRS)

Maghami, Peiman G.; Gupta, Sandeep; Elliott, Kenny B.; Joshi, Suresh M.; Walz, Joseph E.

1994-01-01

This paper describes the first experimental validation of an optimization-based integrated controls-structures design methodology for a class of flexible space structures. The Controls-Structures-Interaction (CSI) Evolutionary Model, a laboratory test bed at Langley, is redesigned based on the integrated design methodology with two different dissipative control strategies. The redesigned structure is fabricated, assembled in the laboratory, and experimentally compared with the original test structure. Design guides are proposed and used in the integrated design process to ensure that the resulting structure can be fabricated. Experimental results indicate that the integrated design requires greater than 60 percent less average control power (by thruster actuators) than the conventional control-optimized design while maintaining the required line-of-sight performance, thereby confirming the analytical findings about the superiority of the integrated design methodology. Amenability of the integrated design structure to other control strategies is considered and evaluated analytically and experimentally. This work also demonstrates the capabilities of the Langley-developed design tool CSI DESIGN which provides a unified environment for structural and control design.

A Hierarchical Modeling Approach to Data Analysis and Study Design in a Multi-Site Experimental fMRI Study

ERIC Educational Resources Information Center

Zhou, Bo; Konstorum, Anna; Duong, Thao; Tieu, Kinh H.; Wells, William M.; Brown, Gregory G.; Stern, Hal S.; Shahbaba, Babak

2013-01-01

We propose a hierarchical Bayesian model for analyzing multi-site experimental fMRI studies. Our method takes the hierarchical structure of the data (subjects are nested within sites, and there are multiple observations per subject) into account and allows for modeling between-site variation. Using posterior predictive model checking and model…

The Effectiveness of Conceptual Change Texts in Remediating High School Students' Alternative Conceptions Concerning Chemical Equilibrium

ERIC Educational Resources Information Center

Ozmen, Haluk

2007-01-01

This study investigated the effectiveness of conceptual change texts in remediating high school students' alternative conceptions concerning chemical equilibrium. A quasi-experimental design was used in this study. The subjects for this study consisted of a total 78 tenth-grade students, 38 of them in the experimental group and 40 of them in the…

Computer Assisted English Language Learning in Costa Rican Elementary Schools: An Experimental Study

ERIC Educational Resources Information Center

Alvarez-Marinelli, Horacio; Blanco, Marta; Lara-Alecio, Rafael; Irby, Beverly J.; Tong, Fuhui; Stanley, Katherine; Fan, Yinan

2016-01-01

This study presents first-year findings of a 25-week longitudinal project derived from a two-year longitudinal randomized trial study at the elementary school level in Costa Rica on effective computer-assisted language learning (CALL) approaches in an English as a foreign language (EFL) setting. A pre-test-post-test experimental group design was…

A Quasi-Experimental Study of Moral Reasoning of Undergraduate Business Students Using an Ethical Decision-Making Framework in a Basic Accounting Course

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…

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

Seapan, M.; Crynes, B.L.; Dale, S.

The objectives of this study were to analyze alternate crudes kinetic hydrotreatment data in the literature, develop a mathematical model for interpretation of these data, develop an experimental procedure and apparatus to collect accurate kinetic data, and finally, to combine the model and experimental data to develop a general model which, with a few experimental parameters, could be used in design of future hydrotreatment processes. These objectives were to cover a four year program (1980 to 1984) and were subjective to sufficient funding. Only partial funding has been available thus far to cover activities for two years. A hydrotreatment datamore » base is developed which contains over 2000 citations, stored in a microcomputer. About 50% of these are reviewed, classified and can be identified by feedstock, catalyst, reactor type and other process characteristics. Tests of published hydrodesulfurization data indicate the problems with simple n-th order, global kinetic models, and point to the value of developing intrinsic reaction kinetic models to describe the reaction processes. A Langmuir-Hinshelwood kinetic model coupled with a plug flow reactor design equation has been developed and used for published data evaluation. An experimental system and procedure have been designed and constructed, which can be used for kinetic studies. 30 references, 4 tables.« less

Effect of asthma management education program on stress and compliance of patients with allergic asthma to house dust mite.

PubMed

Yoo, Yang Sook; Cho, Ok Hee; Kim, Eun Sin; Jeong, Hye Sun

2005-06-01

This study was designed to examine the effect of asthma management education program applied to allergic asthma patients receiving immunotherapy due to house dust mite on their stress and compliance with health care regimens. A quasi experimental design with non-equivalent control group and non-synchronized design was used. The subjects of this study were 61 patients who were receiving immunotherapy at intervals of a week after their symptoms were diagnosed as house dust mite allergic asthma at the pulmonary department of a university hospital in Seoul. They were divided into an experimental group of 29 patients who received asthma management education and a control group of 32 patients. The asthma management education program was composed of group education (once) and reinforcement education (three times) with environmental therapy and immunotherapy to house dust mite. Stress significantly decreased in the experimental group compared to that in the control group. Compliance with health care regimens significantly increased in the experimental group compared to that in the control group. The results suggested that the asthma management education program is effective for the management of stress and the improvement of compliance in patients with allergic asthma to house dust mite.

Effects of Game Design Patterns on Basic Life Support Training Content

ERIC Educational Resources Information Center

Kelle, Sebastian; Klemke, Roland; Specht, Marcus

2013-01-01

Based on a previous analysis of game design patterns and related effects in an educational scenario, the following paper presents an experimental study. In the study a course for Basic Life Support training has been evaluated and two game design patterns have been applied to the course. The hypotheses evaluated in this paper relate to game design…

The Net-Generation Interior Design Student: An Exploratory Study Assessing Learning and Engagement within a Computer Simulation Environment

ERIC Educational Resources Information Center

Peterson, Julie Ellen

2009-01-01

The first purpose of this experimental study was to determine if there were effects on achievement between traditional pencil-and-paper instructional strategies and computer simulated instructional strategies used to teach interior design business ethics. The second purpose was to determine the level of engagement of interior design students using…

Response of Composite Fuselage Sandwich Side Panels Subjected to Internal Pressure and Axial Tension

NASA Technical Reports Server (NTRS)

Rouse, Marshall; Ambur, Damodar R.; Dopker, Bernard; Shah, Bharat

1998-01-01

The results from an experimental and analytical study of two composite sandwich fuselage side panels for a transport aircraft are presented. Each panel has two window cutouts and three frames and utilizes a distinctly different structural concept. These panels have been evaluated with internal pressure loads that generate biaxial tension loading conditions. Design limit load and design ultimate load tests have been performed on both panels. One of the sandwich panels was tested with the middle frame removed to demonstrate the suitability of this two-frame design for supporting the prescribed biaxial loading conditions with twice the initial frame spacing of 20 inches. A damage tolerance study was conducted on the two-frame panel by cutting a notch in the panel that originates at the edge of a cutout and extends in the panel hoop direction through the window-belt area. This panel with a notch was tested in a combined-load condition to demonstrate the structural damage tolerance at the design limit load condition. Both the sandwich panel designs successfully satisfied all desired load requirements in the experimental part of the study, and experimental results from the two-frame panel with and without damage are fully explained by the analytical results. The results of this study suggest that there is potential for using sandwich structural concepts with greater than the usual 20-in. wide frame spacing to further reduce aircraft fuselage structural weight.

A studentized permutation test for three-arm trials in the 'gold standard' design.

PubMed

Mütze, Tobias; Konietschke, Frank; Munk, Axel; Friede, Tim

2017-03-15

The 'gold standard' design for three-arm trials refers to trials with an active control and a placebo control in addition to the experimental treatment group. This trial design is recommended when being ethically justifiable and it allows the simultaneous comparison of experimental treatment, active control, and placebo. Parametric testing methods have been studied plentifully over the past years. However, these methods often tend to be liberal or conservative when distributional assumptions are not met particularly with small sample sizes. In this article, we introduce a studentized permutation test for testing non-inferiority and superiority of the experimental treatment compared with the active control in three-arm trials in the 'gold standard' design. The performance of the studentized permutation test for finite sample sizes is assessed in a Monte Carlo simulation study under various parameter constellations. Emphasis is put on whether the studentized permutation test meets the target significance level. For comparison purposes, commonly used Wald-type tests, which do not make any distributional assumptions, are included in the simulation study. The simulation study shows that the presented studentized permutation test for assessing non-inferiority in three-arm trials in the 'gold standard' design outperforms its competitors, for instance the test based on a quasi-Poisson model, for count data. The methods discussed in this paper are implemented in the R package ThreeArmedTrials which is available on the comprehensive R archive network (CRAN). Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Statistical process control in nursing research.

PubMed

Polit, Denise F; Chaboyer, Wendy

2012-02-01

In intervention studies in which randomization to groups is not possible, researchers typically use quasi-experimental designs. Time series designs are strong quasi-experimental designs but are seldom used, perhaps because of technical and analytic hurdles. Statistical process control (SPC) is an alternative analytic approach to testing hypotheses about intervention effects using data collected over time. SPC, like traditional statistical methods, is a tool for understanding variation and involves the construction of control charts that distinguish between normal, random fluctuations (common cause variation), and statistically significant special cause variation that can result from an innovation. The purpose of this article is to provide an overview of SPC and to illustrate its use in a study of a nursing practice improvement intervention. Copyright © 2011 Wiley Periodicals, Inc.

Conceptual design of a closed loop nutrient solution delivery system for CELSS implementation in a micro-gravity environment

NASA Technical Reports Server (NTRS)

Schwartzkopf, Steven H.; Oleson, Mel W.; Cullingford, Hatice S.

1990-01-01

Described here are the results of a study to develop a conceptual design for an experimental closed loop fluid handling system capable of monitoring, controlling, and supplying nutrient solution to higher plants. The Plant Feeder Experiment (PFE) is designed to be flight tested in a microgravity environment. When flown, the PFX will provide information on both the generic problems of microgravity fluid handling and the specific problems associated with the delivery of the nutrient solution in a microgravity environment. The experimental hardware is designed to fit into two middeck lockers on the Space Shuttle, and incorporates several components that have previously been flight tested.

Results of design studies and wind tunnel tests of an advanced high lift system for an Energy Efficient Transport

NASA Technical Reports Server (NTRS)

Oliver, W. R.

1980-01-01

The development of an advanced technology high lift system for an energy efficient transport incorporating a high aspect ratio supercritical wing is described. This development is based on the results of trade studies to select the high lift system, analysis techniques utilized to design the high lift system, and results of a wind tunnel test program. The program included the first experimental low speed, high Reynolds number wind tunnel test for this class of aircraft. The experimental results include the effects on low speed aerodynamic characteristics of various leading and trailing edge devices, nacelles and pylons, aileron, spoilers, and Mach and Reynolds numbers. Results are discussed and compared with the experimental data and the various aerodynamic characteristics are estimated.

Optimization Method of a Low Cost, High Performance Ceramic Proppant by Orthogonal Experimental Design

NASA Astrophysics Data System (ADS)

Zhou, Y.; Tian, Y. M.; Wang, K. Y.; Li, G.; Zou, X. W.; Chai, Y. S.

2017-09-01

This study focused on optimization method of a ceramic proppant material with both low cost and high performance that met the requirements of Chinese Petroleum and Gas Industry Standard (SY/T 5108-2006). The orthogonal experimental design of L9(34) was employed to study the significance sequence of three factors, including weight ratio of white clay to bauxite, dolomite content and sintering temperature. For the crush resistance, both the range analysis and variance analysis reflected the optimally experimental condition was weight ratio of white clay to bauxite=3/7, dolomite content=3 wt.%, temperature=1350°C. For the bulk density, the most important factor was the sintering temperature, followed by the dolomite content, and then the ratio of white clay to bauxite.

Gut Microbiome Standardization in Control and Experimental Mice.

PubMed

McCoy, Kathy D; Geuking, Markus B; Ronchi, Francesca

2017-04-03

Mouse models are used extensively to study human health and to investigate the mechanisms underlying human disease. In the past, most animal studies were performed without taking into consideration the impact of the microbiota. However, the microbiota that colonizes all body surfaces, including the gastrointestinal tract, respiratory tract, genitourinary tract, and skin, heavily impacts nearly every aspect of host physiology. When performing studies utilizing mouse models it is critical to understand that the microbiome is heavily impacted by environmental factors, including (but not limited to) food, bedding, caging, and temperature. In addition, stochastic changes in the microbiota can occur over time that also play a role in shaping microbial composition. These factors lead to massive variability in the composition of the microbiota between animal facilities and research institutions, and even within a single facility. Lack of experimental reproducibility between research groups has highlighted the necessity for rigorously controlled experimental designs in order to standardize the microbiota between control and experimental animals. Well controlled experiments are mandatory in order to reduce variability and allow correct interpretation of experimental results, not just of host-microbiome studies but of all mouse models of human disease. The protocols presented are aimed to design experiments that control the microbiota composition between different genetic strains of experimental mice within an animal unit. © 2017 by John Wiley & Sons, Inc. Copyright © 2017 John Wiley & Sons, Inc.

The Development of a Cognitive Tool for Teaching and Learning Fractions in the Mathematics Classroom: A Design-Based Study

ERIC Educational Resources Information Center

Kong, S. C.

2008-01-01

Two cycles of design-based research of a cognitive tool (CT) for teaching fractions have been completed. Following the success of a quasi-experimental study of the enhanced CT derived from the second cycle of design-based research, this article reports the findings of a pre-test-post-test control group empirical study using the enhanced CT in the…

Structural similitude and design of scaled down laminated models

NASA Technical Reports Server (NTRS)

Simitses, G. J.; Rezaeepazhand, J.

1993-01-01

The excellent mechanical properties of laminated composite structures make them prime candidates for wide variety of applications in aerospace, mechanical and other branches of engineering. The enormous design flexibility of advanced composites is obtained at the cost of large number of design parameters. Due to complexity of the systems and lack of complete design based informations, designers tend to be conservative in their design. Furthermore, any new design is extensively evaluated experimentally until it achieves the necessary reliability, performance and safety. However, the experimental evaluation of composite structures are costly and time consuming. Consequently, it is extremely useful if a full-scale structure can be replaced by a similar scaled-down model which is much easier to work with. Furthermore, a dramatic reduction in cost and time can be achieved, if available experimental data of a specific structure can be used to predict the behavior of a group of similar systems. This study investigates problems associated with the design of scaled models. Such study is important since it provides the necessary scaling laws, and the factors which affect the accuracy of the scale models. Similitude theory is employed to develop the necessary similarity conditions (scaling laws). Scaling laws provide relationship between a full-scale structure and its scale model, and can be used to extrapolate the experimental data of a small, inexpensive, and testable model into design information for a large prototype. Due to large number of design parameters, the identification of the principal scaling laws by conventional method (dimensional analysis) is tedious. Similitude theory based on governing equations of the structural system is more direct and simpler in execution. The difficulty of making completely similar scale models often leads to accept certain type of distortion from exact duplication of the prototype (partial similarity). Both complete and partial similarity are discussed. The procedure consists of systematically observing the effect of each parameter and corresponding scaling laws. Then acceptable intervals and limitations for these parameters and scaling laws are discussed. In each case, a set of valid scaling factors and corresponding response scaling laws that accurately predict the response of prototypes from experimental models is introduced. The examples used include rectangular laminated plates under destabilizing loads, applied individually, vibrational characteristics of same plates, as well as cylindrical bending of beam-plates.

Wear-screening and joint simulation studies vs. materials selection and prosthesis design.

PubMed

Clarke, I C

1982-01-01

Satisfactory friction and wear performance of orthomedic biomaterials is an essential criterion for both hemiarthroplasty and total joint replacements. This report will chart the clinical historical experience of candidate biomaterials with their wear resistance and compare/contrast these data to experimental test predictions. The latter review will encompass publications dealing with both joint simulators and the more basic friction and wear screening devices. Special consideration will be given to the adequacy of the test protocol, the design of the experimental machines, and the accuracy of the measurement techniques. The discussion will then center on clinical reality vs. experimental adequacy and summarize current developments.

On Design Experiment Teaching in Engineering Quality Cultivation

ERIC Educational Resources Information Center

Chen, Xiao

2008-01-01

Design experiment refers to that designed and conducted by students independently and is surely an important method to cultivate students' comprehensive quality. According to the development and requirements of experimental teaching, this article carries out a study and analysis on the purpose, significance, denotation, connotation and…

40 CFR 158.70 - Satisfying data requirements.

Code of Federal Regulations, 2010 CFR

2010-07-01

... the data requirement. In evaluating experimental design, the Agency will consider whether generally... specified in this part are acceptable. This determination will be based on the design and conduct of the... conduct of each experiment in terms of whether the study was conducted in conformance with the design...

40 CFR 158.70 - Satisfying data requirements.

Code of Federal Regulations, 2011 CFR

2011-07-01

... the data requirement. In evaluating experimental design, the Agency will consider whether generally... specified in this part are acceptable. This determination will be based on the design and conduct of the... conduct of each experiment in terms of whether the study was conducted in conformance with the design...

40 CFR 158.70 - Satisfying data requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

... the data requirement. In evaluating experimental design, the Agency will consider whether generally... specified in this part are acceptable. This determination will be based on the design and conduct of the... conduct of each experiment in terms of whether the study was conducted in conformance with the design...

40 CFR 158.70 - Satisfying data requirements.

Code of Federal Regulations, 2013 CFR

2013-07-01

... the data requirement. In evaluating experimental design, the Agency will consider whether generally... specified in this part are acceptable. This determination will be based on the design and conduct of the... conduct of each experiment in terms of whether the study was conducted in conformance with the design...

40 CFR 161.80 - Acceptability of data.

Code of Federal Regulations, 2011 CFR

2011-07-01

... the data requirement. In evaluating experimental design, the Agency will consider whether generally... specified in this part are acceptable. This determination will be based on the design and conduct of the... conduct of each experiment in terms of whether the study was conducted in conformance with the design...

40 CFR 158.70 - Satisfying data requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

... the data requirement. In evaluating experimental design, the Agency will consider whether generally... specified in this part are acceptable. This determination will be based on the design and conduct of the... conduct of each experiment in terms of whether the study was conducted in conformance with the design...

40 CFR 161.80 - Acceptability of data.

Code of Federal Regulations, 2013 CFR

2013-07-01

... the data requirement. In evaluating experimental design, the Agency will consider whether generally... specified in this part are acceptable. This determination will be based on the design and conduct of the... conduct of each experiment in terms of whether the study was conducted in conformance with the design...

40 CFR 161.80 - Acceptability of data.

Code of Federal Regulations, 2010 CFR

2010-07-01

... the data requirement. In evaluating experimental design, the Agency will consider whether generally... specified in this part are acceptable. This determination will be based on the design and conduct of the... conduct of each experiment in terms of whether the study was conducted in conformance with the design...

40 CFR 161.80 - Acceptability of data.

Code of Federal Regulations, 2012 CFR

2012-07-01

... the data requirement. In evaluating experimental design, the Agency will consider whether generally... specified in this part are acceptable. This determination will be based on the design and conduct of the... conduct of each experiment in terms of whether the study was conducted in conformance with the design...

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

Riggs, J.B.

An experimental test model, which is dynamically similar to an actual UCC (Underground Coal Conversion) system, was used to determine fluid-flow patterns and local heat transfer that occur in the UCC burn cavity. This study was designed to provide insight into the little understood mechanisms (i.e., heat transfer and oxygen transport to the cavity walls) that control maximum cavity width, and therefore resource recovery during UCC. The experimental studies will be designed to study the effects of a growing cavity upon the transport to the side walls of a UCG cavity. The flow model will be used to study themore » effects of rubble pile shape changes upon the transport to the side walls.« less

Experimental Design for Combinatorial and High Throughput Materials Development

NASA Astrophysics Data System (ADS)

Cawse, James N.

2002-12-01

In the past decade, combinatorial and high throughput experimental methods have revolutionized the pharmaceutical industry, allowing researchers to conduct more experiments in a week than was previously possible in a year. Now high throughput experimentation is rapidly spreading from its origins in the pharmaceutical world to larger industrial research establishments such as GE and DuPont, and even to smaller companies and universities. Consequently, researchers need to know the kinds of problems, desired outcomes, and appropriate patterns for these new strategies. Editor James Cawse's far-reaching study identifies and applies, with specific examples, these important new principles and techniques. Experimental Design for Combinatorial and High Throughput Materials Development progresses from methods that are now standard, such as gradient arrays, to mathematical developments that are breaking new ground. The former will be particularly useful to researchers entering the field, while the latter should inspire and challenge advanced practitioners. The book's contents are contributed by leading researchers in their respective fields. Chapters include: -High Throughput Synthetic Approaches for the Investigation of Inorganic Phase Space -Combinatorial Mapping of Polymer Blends Phase Behavior -Split-Plot Designs -Artificial Neural Networks in Catalyst Development -The Monte Carlo Approach to Library Design and Redesign This book also contains over 200 useful charts and drawings. Industrial chemists, chemical engineers, materials scientists, and physicists working in combinatorial and high throughput chemistry will find James Cawse's study to be an invaluable resource.

City Connects: Building an Argument for Effects on Student Achievement with a Quasi-Experimental Design

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…

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…

Robustness of crossover trials against subject drop-out - Examples of perpetually connected designs.

PubMed

Godolphin, P J; Godolphin, E J

2017-01-01

When performing a repeated measures experiment, such as a clinical trial, there is a risk of subject drop-out during the experiment. If one or more subjects leave the study prematurely, a situation could arise where the eventual design is disconnected, implying that very few treatment contrasts for both direct effects and carryover effects are estimable. This paper aims to identify experimental conditions where this problem with the eventual design can be avoided. It is shown that in the class of uniformly balanced repeated measurement designs consisting of two or more Latin squares, there are planned designs with the following useful property. Provided that all subjects have completed the first two periods of study, such a design will not be replaced by a disconnected eventual design due to drop-out, irrespective of the type of drop-out behaviour that may occur. Designs with this property are referred to as perpetually connected. These experimental conditions are identified and examined in the paper and an example of at least one perpetually connected uniformly balanced repeated measurement design is given in each case. The results improve upon previous contributions in the literature that have been confined largely to cases in which drop-out occurs only in the final periods of study.

42 CFR 405.212 - Medicare Coverage IDE study criteria.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Medicare coverage of items and services described in § 405.211, a Category A (Experimental) or Category B...) The study design is methodologically appropriate and the anticipated number of enrolled subjects is... CFR parts 50, 56, and 812 and 45 CFR part 46. (7) Where appropriate, the study is not designed to...

76 FR 10573 - Notice of Proposed Information Collection Requests

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-25

... study will use quasi- experimental designs to explore the relationship between magnet programs and... that (1) described the study design and full data collection activities and (2) requested approval for... associated with the fourth and fifth year of data collection necessary for the rigorous comparative...

Experimental designs for detecting synergy and antagonism between two drugs in a pre-clinical study.

PubMed

Sperrin, Matthew; Thygesen, Helene; Su, Ting-Li; Harbron, Chris; Whitehead, Anne

2015-01-01

The identification of synergistic interactions between combinations of drugs is an important area within drug discovery and development. Pre-clinically, large numbers of screening studies to identify synergistic pairs of compounds can often be ran, necessitating efficient and robust experimental designs. We consider experimental designs for detecting interaction between two drugs in a pre-clinical in vitro assay in the presence of uncertainty of the monotherapy response. The monotherapies are assumed to follow the Hill equation with common lower and upper asymptotes, and a common variance. The optimality criterion used is the variance of the interaction parameter. We focus on ray designs and investigate two algorithms for selecting the optimum set of dose combinations. The first is a forward algorithm in which design points are added sequentially. This is found to give useful solutions in simple cases but can lack robustness when knowledge about the monotherapy parameters is insufficient. The second algorithm is a more pragmatic approach where the design points are constrained to be distributed log-normally along the rays and monotherapy doses. We find that the pragmatic algorithm is more stable than the forward algorithm, and even when the forward algorithm has converged, the pragmatic algorithm can still out-perform it. Practically, we find that good designs for detecting an interaction have equal numbers of points on monotherapies and combination therapies, with those points typically placed in positions where a 50% response is expected. More uncertainty in monotherapy parameters leads to an optimal design with design points that are more spread out. Copyright © 2015 John Wiley & Sons, Ltd.

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

Nabeel A. Riza

The goals of the first six months of this project were to lay the foundations for both the SiC front-end optical chip fabrication as well as the free-space laser beam interferometer designs and preliminary tests. In addition, a Phase I goal was to design and experimentally build the high temperature and pressure infrastructure and test systems that will be used in the next 6 months for proposed sensor experimentation and data processing. All these goals have been achieved and are described in detail in the report. Both design process and diagrams for the mechanical elements as well as the opticalmore » systems are provided. In addition, photographs of the fabricated SiC optical chips, the high temperature & pressure test chamber instrument, the optical interferometer, the SiC sample chip holder, and signal processing data are provided. The design and experimentation results are summarized to give positive conclusions on the proposed novel high temperature optical sensor technology. The goals of the second six months of this project were to conduct high temperature sensing tests using the test chamber and optical sensing instrument designs developed in the first part of the project. In addition, a Phase I goal was to develop the basic processing theory and physics for the proposed first sensor experimentation and data processing. All these goals have been achieved and are described in detail. Both optical experimental design process and sensed temperature are provided. In addition, photographs of the fabricated SiC optical chips after deployment in the high temperature test chamber are shown from a material study point-of-view.« less

A Computational and Experimental Investigation of a Three-Dimensional Hypersonic Scramjet Inlet Flow Field. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Holland, Scott Douglas

1991-01-01

A combined computational and experimental parametric study of the internal aerodynamics of a generic three dimensional sidewall compression scramjet inlet configuration was performed. The study was designed to demonstrate the utility of computational fluid dynamics as a design tool in hypersonic inlet flow fields, to provide a detailed account of the nature and structure of the internal flow interactions, and to provide a comprehensive surface property and flow field database to determine the effects of contraction ratio, cowl position, and Reynolds number on the performance of a hypersonic scramjet inlet configuration.

Modeling and Experiments with Carbon Nanotubes for Applications in High Performance Circuits

DTIC Science & Technology

2017-04-06

purchased and installed for experimental characterization of atomic layer deposited graphene on different substrates for radiation-hardened studies...72 3.6 Experimental Research in Graphene for Radiation Hardened Devices……………..73 4 Recommendations...physics for analysis and design of integrated circuits. The developed model is verified from published experimental data. Basic logic gates in

Military Personnel Attrition and Retention: Research in Progress

DTIC Science & Technology

1981-10-01

designed to assess the relative risks of attrition among non -h.gh. school graduate Army enlistees. As a group, these individuals historically...this methodology see the Majcýhrzak paper in this volume) Research in the PlanningStaaqe Stage ’TV: Administrative Experimentation In order to derive...different research designs : 1. True experimental designs ; 2. Correlational research designs ; 3. Quasi- experimental research designs . We rejected the idea

Mirrors design, analysis and manufacturing of the 550mm Korsch telescope experimental model

NASA Astrophysics Data System (ADS)

Huang, Po-Hsuan; Huang, Yi-Kai; Ling, Jer

2017-08-01

In 2015, NSPO (National Space Organization) began to develop the sub-meter resolution optical remote sensing instrument of the next generation optical remote sensing satellite which follow-on to FORMOSAT-5. Upgraded from the Ritchey-Chrétien Cassegrain telescope optical system of FORMOSAT-5, the experimental optical system of the advanced optical remote sensing instrument was enhanced to an off-axis Korsch telescope optical system which consists of five mirrors. It contains: (1) M1: 550mm diameter aperture primary mirror, (2) M2: secondary mirror, (3) M3: off-axis tertiary mirror, (4) FM1 and FM2: two folding flat mirrors, for purpose of limiting the overall volume, reducing the mass, and providing a long focal length and excellent optical performance. By the end of 2015, we implemented several important techniques including optical system design, opto-mechanical design, FEM and multi-physics analysis and optimization system in order to do a preliminary study and begin to develop and design these large-size lightweight aspheric mirrors and flat mirrors. The lightweight mirror design and opto-mechanical interface design were completed in August 2016. We then manufactured and polished these experimental model mirrors in Taiwan; all five mirrors ware completed as spherical surfaces by the end of 2016. Aspheric figuring, assembling tests and optical alignment verification of these mirrors will be done with a Korsch telescope experimental structure model in 2018.

BioNetCAD: design, simulation and experimental validation of synthetic biochemical networks

PubMed Central

Rialle, Stéphanie; Felicori, Liza; Dias-Lopes, Camila; Pérès, Sabine; El Atia, Sanaâ; Thierry, Alain R.; Amar, Patrick; Molina, Franck

2010-01-01

Motivation: Synthetic biology studies how to design and construct biological systems with functions that do not exist in nature. Biochemical networks, although easier to control, have been used less frequently than genetic networks as a base to build a synthetic system. To date, no clear engineering principles exist to design such cell-free biochemical networks. Results: We describe a methodology for the construction of synthetic biochemical networks based on three main steps: design, simulation and experimental validation. We developed BioNetCAD to help users to go through these steps. BioNetCAD allows designing abstract networks that can be implemented thanks to CompuBioTicDB, a database of parts for synthetic biology. BioNetCAD enables also simulations with the HSim software and the classical Ordinary Differential Equations (ODE). We demonstrate with a case study that BioNetCAD can rationalize and reduce further experimental validation during the construction of a biochemical network. Availability and implementation: BioNetCAD is freely available at http://www.sysdiag.cnrs.fr/BioNetCAD. It is implemented in Java and supported on MS Windows. CompuBioTicDB is freely accessible at http://compubiotic.sysdiag.cnrs.fr/ Contact: stephanie.rialle@sysdiag.cnrs.fr; franck.molina@sysdiag.cnrs.fr Supplementary information: Supplementary data are available at Bioinformatics online. PMID:20628073

Experimental realization of dynamo action: present status and prospects

NASA Astrophysics Data System (ADS)

Giesecke, André; Stefani, Frank; Gundrum, Thomas; Gerbeth, Gunter; Nore, Caroline; Léorat, Jacques

2013-07-01

In the last decades, the experimental study of dynamo action has made great progress. However, after the dynamo experiments in Karlsruhe and Riga, the von-Kármán-Sodium (VKS) dynamo is only the third facility that has been able to demonstrate fluid flow driven self-generation of magnetic fields in a laboratory experiment. Further progress in the experimental examination of dynamo action is expected from the planned precession driven dynamo experiment that will be designed in the framework of the liquid sodium facility DRESDYN (DREsden Sodium facility for DYNamo and thermohydraulic studies). In this paper, we briefly present numerical models of the VKS dynamo that demonstrate the close relation between the axisymmetric field observed in that experiment and the soft iron material used for the flow driving impellers. We further show recent results of preparatory water experiments and design studies related to the precession dynamo and delineate the scientific prospects for the final set-up.

Effects of aromatherapy massage on anxiety and self-esteem in korean elderly women: a pilot study.

PubMed

Rho, Kook-Hee; Han, Sun-Hee; Kim, Keum-Soon; Lee, Myeong Soo

2006-12-01

This study investigated the effects of aromatherapy massage on the anxiety and self-esteem experienced by Korean elderly women. A quasi-experimental, control group, pretest-posttest design was used. The subjects comprised 36 elderly females: 16 in the experimental group and 20 in the control group. Aromatherapy massage using lavender, chamomile, rosemary, and lemon was given to the experimental group only. Each massage session lasted 20 min, and was performed 3 times per week for two 3-week periods with an intervening 1-week break. The intervention produced significant differences in the anxiety and self-esteem and no significant differences in blood pressure or pulse rate between the two groups. These results suggest that aromatherapy massage exerts positive effects on anxiety and self-esteem. However, more objective, clinical measures should be applied in a future study with a randomized placebo-controlled design.

A comparison of between- and within-subjects imitation designs.

PubMed

Kressley, Regina A; Knopf, Monika

2006-12-01

Two experimental methods, which have dominated the study of declarative memory in preverbal children with imitation tasks, namely the deferred imitation and elicited imitation paradigm, differ in the amount of physical contact with test stimuli afforded infants prior to a test for long-term recall. The current study assessed effects of pre- and post-demonstration contact with test stimuli on deferred imitation of novel, single-step unrelated actions with multiple objects by 8(1/2)- and 10(1/2)-month-old infants (N=50). The rate of target action completion after a delay remained consistent at both ages across different conditions of prior contact with test stimuli. This study shows that a within-subjects baseline appraisal is valid within certain experimental parameters and offers a more economical alternative. The results show furthermore that different experimental designs utilized to assess deferred imitation are highly comparable for the first year despite differences in determining baseline.

Experimental parametric study of servers cooling management in data centers buildings

NASA Astrophysics Data System (ADS)

Nada, S. A.; Elfeky, K. E.; Attia, Ali M. A.; Alshaer, W. G.

2017-06-01

A parametric study of air flow and cooling management of data centers servers is experimentally conducted for different design conditions. A physical scale model of data center accommodating one rack of four servers was designed and constructed for testing purposes. Front and rear rack and server's temperatures distributions and supply/return heat indices (SHI/RHI) are used to evaluate data center thermal performance. Experiments were conducted to parametrically study the effects of perforated tiles opening ratio, servers power load variation and rack power density. The results showed that (1) perforated tile of 25% opening ratio provides the best results among the other opening ratios, (2) optimum benefit of cold air in servers cooling is obtained at uniformly power loading of servers (3) increasing power density decrease air re-circulation but increase air bypass and servers temperature. The present results are compared with previous experimental and CFD results and fair agreement was found.

A Quasi-Experimental Study of Two Selected Units of the Industrial Arts Curriculum Project Materials to Determine the Measurable Additive Effects of a Unit on Design in Manfacturing Technology upon a Similar Unit on Design in Construction Technology.

ERIC Educational Resources Information Center

Kuwik, Paul David

The purpose of the study was to determine whether exposing junior high school students to a unit on design in construction technology and to a unit on design in manufacturing technology significantly affects their achievement on a test measuring "Technological Principles of Design" when compared to a group of junior high school students exposed…

Neural Network Models of Simple Mechanical Systems Illustrating the Feasibility of Accelerated Life Testing

NASA Technical Reports Server (NTRS)

Fusaro, Robert L.; Jones, Steven P.; Jansen, Ralph

1996-01-01

A complete evaluation of the tribological characteristics of a given material/mechanical system is a time-consuming operation since the friction and wear process is extremely systems sensitive. As a result, experimental designs (i.e., Latin Square, Taguchi) have been implemented in an attempt to not only reduce the total number of experimental combinations needed to fully characterize a material/mechanical system, but also to acquire life data for a system without having to perform an actual life test. Unfortunately, these experimental designs still require a great deal of experimental testing and the output does not always produce meaningful information. In order to further reduce the amount of experimental testing required, this study employs a computer neural network model to investigate different material/mechanical systems. The work focuses on the modeling of the wear behavior, while showing the feasibility of using neural networks to predict life data. The model is capable of defining which input variables will influence the tribological behavior of the particular material/mechanical system being studied based on the specifications of the overall system.

48 CFR 27.303 - Contract clauses.

Code of Federal Regulations, 2010 CFR

2010-10-01

...)(1) Insert a patent rights clause in all solicitations and contracts for experimental, developmental... contracts for construction work or architect-engineer services that include— (i) Experimental, developmental, or research work; (ii) Test and evaluation studies; or (iii) The design of a Government facility that...

48 CFR 27.303 - Contract clauses.

Code of Federal Regulations, 2013 CFR

2013-10-01

...)(1) Insert a patent rights clause in all solicitations and contracts for experimental, developmental... contracts for construction work or architect-engineer services that include— (i) Experimental, developmental, or research work; (ii) Test and evaluation studies; or (iii) The design of a Government facility that...

48 CFR 27.303 - Contract clauses.

Code of Federal Regulations, 2014 CFR

2014-10-01

...)(1) Insert a patent rights clause in all solicitations and contracts for experimental, developmental... contracts for construction work or architect-engineer services that include— (i) Experimental, developmental, or research work; (ii) Test and evaluation studies; or (iii) The design of a Government facility that...

48 CFR 27.303 - Contract clauses.

Code of Federal Regulations, 2011 CFR

2011-10-01

...)(1) Insert a patent rights clause in all solicitations and contracts for experimental, developmental... contracts for construction work or architect-engineer services that include— (i) Experimental, developmental, or research work; (ii) Test and evaluation studies; or (iii) The design of a Government facility that...

A critical assessment of the photodegradation of pharmaceuticals in aquatic environments: defining our current understanding and identifying knowledge gaps.

PubMed

Challis, Jonathan K; Hanson, Mark L; Friesen, Ken J; Wong, Charles S

2014-04-01

This work presents a critical assessment of the state and quality of knowledge around the aquatic photochemistry of human- and veterinary-use pharmaceuticals from laboratory experiments and field observations. A standardized scoring rubric was used to assess relevant studies within four categories: experimental design, laboratory-based direct and indirect photolysis, and field/solar photolysis. Specific metrics for each category are defined to evaluate various aspects of experimental design (e.g., higher scores are given for more appropriate characterization of light source wavelength distribution). This weight of evidence-style approach allowed for identification of knowledge strengths and gaps covering three areas: first, the general extent of photochemical data for specific pharmaceuticals and classes; second, the overall quality of existing data (i.e., strong versus weak); and finally, trends in the photochemistry research around these specific compounds, e.g. the observation of specific and consistent oversights in experimental design. In general, those drugs that were most studied also had relatively good quality data. The four pharmaceuticals studied experimentally at least ten times in the literature had average total scores (lab and field combined) of ≥29, considered decent quality; carbamazepine (13 studies; average score of 31), diclofenac (12 studies; average score of 31), sulfamethoxazole (11 studies; average score of 34), and propranolol (11 studies; average score of 29). Major oversights and errors in data reporting and/or experimental design included: lack of measurement and reporting of incident light source intensity, lack of appropriate controls, use of organic co-solvents in irradiation solutions, and failure to consider solution pH. Consequently, a number of these experimental parameters were likely a cause of inconsistent measurements of direct photolysis rate constants and quantum yields, two photochemical properties that were highly variable in the literature. Overall, the assessment rubric provides an objective and scientifically-defensible set of metrics for assessing the quality of a study. A major recommendation is the development of a method guideline, based on this rubric, for conducting and reporting on photochemical studies that would produce consistent and reliable data for quantitative comparison across studies. Furthermore, an emphasis should be placed on conducting more dual-fate studies involving controlled photolysis experiments in natural sunlight, and whole system fate studies in either natural or artificial systems. This would provide accurate data describing the actual contribution of photolysis to the overall fate of pharmaceuticals in the environment.

Conceptual design study of Fusion Experimental Reactor (FY86 FER): Safety

NASA Astrophysics Data System (ADS)

Seki, Yasushi; Iida, Hiromasa; Honda, Tsutomu

1987-08-01

This report describes the study on safety for FER (Fusion Experimental Reactor) which has been designed as a next step machine to the JT-60. Though the final purpose of this study is to have an image of design base accident, maximum credible accident and to assess their risk or probability, etc., as FER plant system, the emphasis of this years study is placed on fuel-gas circulation system where the tritium inventory is maximum. The report consists of two chapters. The first chapter summarizes the FER system and describes FMEA (Failure Mode and Effect Analysis) and related accident progression sequence for FER plant system as a whole. The second chapter of this report is focused on fuel-gas circulation system including purification, isotope separation and storage. Probability of risk is assessed by the probabilistic risk analysis (PRA) procedure based on FMEA, ETA and FTA.

False Dichotomies and Health Policy Research Designs: Randomized Trials Are Not Always the Answer.

PubMed

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.

Three-dimensional shape optimization of a cemented hip stem and experimental validations.

PubMed

Higa, Masaru; Tanino, Hiromasa; Nishimura, Ikuya; Mitamura, Yoshinori; Matsuno, Takeo; Ito, Hiroshi

2015-03-01

This study proposes novel optimized stem geometry with low stress values in the cement using a finite element (FE) analysis combined with an optimization procedure and experimental measurements of cement stress in vitro. We first optimized an existing stem geometry using a three-dimensional FE analysis combined with a shape optimization technique. One of the most important factors in the cemented stem design is to reduce stress in the cement. Hence, in the optimization study, we minimized the largest tensile principal stress in the cement mantle under a physiological loading condition by changing the stem geometry. As the next step, the optimized stem and the existing stem were manufactured to validate the usefulness of the numerical models and the results of the optimization in vitro. In the experimental study, strain gauges were embedded in the cement mantle to measure the strain in the cement mantle adjacent to the stems. The overall trend of the experimental study was in good agreement with the results of the numerical study, and we were able to reduce the largest stress by more than 50% in both shape optimization and strain gauge measurements. Thus, we could validate the usefulness of the numerical models and the results of the optimization using the experimental models. The optimization employed in this study is a useful approach for developing new stem designs.

A Parametric Geometry Computational Fluid Dynamics (CFD) Study Utilizing Design of Experiments (DOE)

NASA Technical Reports Server (NTRS)

Rhew, Ray D.; Parker, Peter A.

2007-01-01

Design of Experiments (DOE) was applied to the LAS geometric parameter study to efficiently identify and rank primary contributors to integrated drag over the vehicles ascent trajectory in an order of magnitude fewer CFD configurations thereby reducing computational resources and solution time. SME s were able to gain a better understanding on the underlying flowphysics of different geometric parameter configurations through the identification of interaction effects. An interaction effect, which describes how the effect of one factor changes with respect to the levels of other factors, is often the key to product optimization. A DOE approach emphasizes a sequential approach to learning through successive experimentation to continuously build on previous knowledge. These studies represent a starting point for expanded experimental activities that will eventually cover the entire design space of the vehicle and flight trajectory.

Design standards for experimental and field studies to evaluate diagnostic accuracy of tests for infectious diseases in aquatic animals.

PubMed

Laurin, E; Thakur, K K; Gardner, I A; Hick, P; Moody, N J G; Crane, M S J; Ernst, I

2018-05-01

Design and reporting quality of diagnostic accuracy studies (DAS) are important metrics for assessing utility of tests used in animal and human health. Following standards for designing DAS will assist in appropriate test selection for specific testing purposes and minimize the risk of reporting biased sensitivity and specificity estimates. To examine the benefits of recommending standards, design information from published DAS literature was assessed for 10 finfish, seven mollusc, nine crustacean and two amphibian diseases listed in the 2017 OIE Manual of Diagnostic Tests for Aquatic Animals. Of the 56 DAS identified, 41 were based on field testing, eight on experimental challenge studies and seven on both. Also, we adapted human and terrestrial-animal standards and guidelines for DAS structure for use in aquatic animal diagnostic research. Through this process, we identified and addressed important metrics for consideration at the design phase: study purpose, targeted disease state, selection of appropriate samples and specimens, laboratory analytical methods, statistical methods and data interpretation. These recommended design standards for DAS are presented as a checklist including risk-of-failure points and actions to mitigate bias at each critical step. Adherence to standards when designing DAS will also facilitate future systematic review and meta-analyses of DAS research literature. © 2018 John Wiley & Sons Ltd.

76 FR 9331 - Professional Development for Arts Educators Program; Office of Innovation and Improvement...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-17

... adaptation of an interrupted time series design that relies on the comparison of treatment effects on a... group designs (as defined in this notice), interrupted time series designs (as defined in this notice... series design means a type of quasi-experimental study (as defined in this notice) in which the outcome...

Integrating Geospatial Technologies in Fifth-Grade Curriculum: Impact on Spatial Ability and Map-Analysis Skills

ERIC Educational Resources Information Center

Jadallah, May; Hund, Alycia M.; Thayn, Jonathan; Studebaker, Joel Garth; Roman, Zachary J.; Kirby, Elizabeth

2017-01-01

This study explores the effects of geographic information systems (GIS) curriculum on fifth-grade students' spatial ability and map-analysis skills. A total of 174 students from an urban public school district and their teachers participated in a quasi-experimental design study. Four teachers implemented a GIS curriculum in experimental classes…

Effects of Three Pedagogies on Learning Outcomes in a Psychology of Gender Lecture: A Quasi-Experimental Study

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…

The Effects of Television Advertising on Children. Report No. 2: Second Year Experimental Evidence. Final Report.

ERIC Educational Resources Information Center

Atkin, Charles K.

This report, the second in a series of six reports on television advertising and children, presents the results from a series of experimental studies designed to test children's intentional and incidental learning from television commercials. A total of 400 elementary school students of varying socioeconomic status participated in the study, with…

Microteaching and Pre-Service Teachers' Sense of Self-Efficacy in Teaching

ERIC Educational Resources Information Center

Arsal, Zeki

2014-01-01

This study examined the effect of microteaching on pre-service teachers' sense of self-efficacy in teaching using a pre-test/post-test quasi-experimental design. The sample of the study consisted of 70 pre-service teachers on a special education teacher preparation programme. The pre-service teachers in the experimental group were exposed to…

An Experimental Study Comparing English-Only and Transitional Bilingual Education on Spanish-Speaking Preschoolers' Early Literacy Development

ERIC Educational Resources Information Center

Duran, Lillian K.; Roseth, Cary J.; Hoffman, Patricia

2010-01-01

A longitudinal, experimental-control design was used to test the hypothesis that native language instruction enhances English language learner's (ELL's) native language and literacy development without significant cost to English development. In this study, 31 Spanish-speaking preschoolers (aged 38-48 months) were randomly assigned to two Head…

The Impact of Concept Mapping on EFL Learners' Critical Thinking Ability

ERIC Educational Resources Information Center

Khodadady, Ebrahim; Ghanizadeh, Afsaneh

2011-01-01

The present study investigated the influence of concept mapping as a post-reading strategy on EFL learners' critical thinking ability. The study utilized a pretest-posttest control and experimental group design. To do so, thirty six EFL learners at upper intermediate and advanced levels were randomly assigned to experimental (n=18) and control…

Enhancing Foreign Language Learning through Listening Strategies Delivered in L1: An Experimental Study

ERIC Educational Resources Information Center

Bozorgian, Hossein; Pillay, Hitendra

2013-01-01

Listening used in language teaching refers to a complex process that allows us to understand spoken language. The current study, conducted in Iran with an experimental design, investigated the effectiveness of teaching listening strategies delivered in L1 (Persian) and its effect on listening comprehension in L2. Five listening strategies:…

Associating Animations with Concrete Models to Enhance Students' Comprehension of Different Visual Representations in Organic Chemistry

ERIC Educational Resources Information Center

Al-Balushi, Sulaiman M.; Al-Hajri, Sheikha H.

2014-01-01

The purpose of the current study is to explore the impact of associating animations with concrete models on eleventh-grade students' comprehension of different visual representations in organic chemistry. The study used a post-test control group quasi-experimental design. The experimental group (N = 28) used concrete models, submicroscopic…

An Intervention Including an Online Game to Improve Grade 6 Students' Performance in Early Algebra

ERIC Educational Resources Information Center

Kolovou, Angeliki; van den Heuvel-Panhuizen, Marja; Koller, Olaf

2013-01-01

This study investigated whether an intervention including an online game contributed to 236 Grade 6 students' performance in early algebra, that is, solving problems with covarying quantities. An exploratory quasi-experimental study was conducted with a pretest-posttest-control-group design. Students in the experimental group were asked to solve…

Developing Business Management Students' Persuasive Writing through Blog-Based Peer-Feedback

ERIC Educational Resources Information Center

Sayed, Osama H.

2010-01-01

The present study attempted to investigate the effect of using blog-based peer feedback on the persuasive writing of EFL business management students at the community college in Bisha, King Khalid University, Saudi Arabia. The study used a pre-test/post-test experimental and control group design. An experimental group and a control group were…

Synthesis of Single-Case Experimental Data: A Comparison of Alternative Multilevel Approaches

ERIC Educational Resources Information Center

Ferron, John; Van den Noortgate, Wim; Beretvas, Tasha; Moeyaert, Mariola; Ugille, Maaike; Petit-Bois, Merlande; Baek, Eun Kyeng

2013-01-01

Single-case or single-subject experimental designs (SSED) are used to evaluate the effect of one or more treatments on a single case. Although SSED studies are growing in popularity, the results are in theory case-specific. One systematic and statistical approach for combining single-case data within and across studies is multilevel modeling. The…

A Systematic Review of Universal Campaigns Targeting Child Physical Abuse Prevention

ERIC Educational Resources Information Center

Poole, Mary Kathryn; Seal, David W.; Taylor, Catherine A.

2014-01-01

The purpose of this review was to better understand the impact of universal campaign interventions with a media component aimed at preventing child physical abuse (CPA). The review included 17 studies featuring 15 campaigns conducted from 1989 to 2011 in five countries. Seven studies used experimental designs, but most were quasi-experimental. CPA…

76 FR 21379 - Agency Information Collection Activities; Proposed Collection; Comment Request; Experiment To...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-15

... CRCR will design and administer the study. FDA is requesting OMB approval under the PRA for the CRCR to... distribution chain (Ref. 3). The goal of the proposed project is to test, by experimental study, whether the... will be assigned to one of the following experimental conditions (consisting of vignettes in the form...

Demonstration Technique to Improve Vocabulary and Grammar Element in Teaching Speaking at EFL Learners

ERIC Educational Resources Information Center

Husnu, Muhammad

2018-01-01

This study aimed at examining the effectiveness of demonstration technique to improve vocabulary and grammar element in teaching speaking at EFL learners. This research applied true-experimental design. The respondents of the study were 32 students (class IIA) as experimental group and 32 students (class IIB) as control group from the second…

An Action Research Study on the Effect of Interactive Technology and Active Learning on Student Performance

ERIC Educational Resources Information Center

Bear, Teresa J.

2013-01-01

This quantitative action science research study utilized a causal-comparative experimental research design in order to determine if the use of student response systems (clickers), as an active learning strategy in a community college course, improved student performance in the course. Students in the experimental group (n = 26) used clickers to…

An Analysis of State Assessment Policies Addressing the Accommodation of English Language Learners

ERIC Educational Resources Information Center

Rivera, Carlene; Collum, Eric

2004-01-01

This paper reviews 15 research studies that: (1) examined effects of particular accommodations or groups of accommodations on performance: and (2) employed experimental and quasi-experimental research designs that allowed examination of the effect of the accommodation(s) on English Language Learners (ELLs) and non-ELLs. Studies looked at one or…

Study and design of cryogenic propellant acquisition systems. Volume 2: Supporting experimental program

NASA Technical Reports Server (NTRS)

Burge, G. W.; Blackmon, J. B.

1973-01-01

Areas of cryogenic fuel systems were identified where critical experimental information was needed either to define a design criteria or to establish the feasibility of a design concept or a critical aspect of a particular design. Such data requirements fell into three broad categories: (1) basic surface tension screen characteristics; (2) screen acquisition device fabrication problems; and (3) screen surface tension device operational failure modes. To explore these problems and to establish design criteria where possible, extensive laboratory or bench test scale experiments were conducted. In general, these proved to be quite successful and, in many instances, the test results were directly used in the system design analyses and development. In some cases, particularly those relating to operational-type problems, areas requiring future research were identified, especially screen heat transfer and vibrational effects.

A global parallel model based design of experiments method to minimize model output uncertainty.

PubMed

Bazil, Jason N; Buzzard, Gregory T; Rundell, Ann E

2012-03-01

Model-based experiment design specifies the data to be collected that will most effectively characterize the biological system under study. Existing model-based design of experiment algorithms have primarily relied on Fisher Information Matrix-based methods to choose the best experiment in a sequential manner. However, these are largely local methods that require an initial estimate of the parameter values, which are often highly uncertain, particularly when data is limited. In this paper, we provide an approach to specify an informative sequence of multiple design points (parallel design) that will constrain the dynamical uncertainty of the biological system responses to within experimentally detectable limits as specified by the estimated experimental noise. The method is based upon computationally efficient sparse grids and requires only a bounded uncertain parameter space; it does not rely upon initial parameter estimates. The design sequence emerges through the use of scenario trees with experimental design points chosen to minimize the uncertainty in the predicted dynamics of the measurable responses of the system. The algorithm was illustrated herein using a T cell activation model for three problems that ranged in dimension from 2D to 19D. The results demonstrate that it is possible to extract useful information from a mathematical model where traditional model-based design of experiments approaches most certainly fail. The experiments designed via this method fully constrain the model output dynamics to within experimentally resolvable limits. The method is effective for highly uncertain biological systems characterized by deterministic mathematical models with limited data sets. Also, it is highly modular and can be modified to include a variety of methodologies such as input design and model discrimination.

A realist review of one-to-one breastfeeding peer support experiments conducted in developed country settings.

PubMed

Trickey, Heather; Thomson, Gill; Grant, Aimee; Sanders, Julia; Mann, Mala; Murphy, Simon; Paranjothy, Shantini

2018-01-01

The World Health Organisation guidance recommends breastfeeding peer support (BFPS) as part of a strategy to improve breastfeeding rates. In the UK, BFPS is supported by National Institute for Health and Care Excellence guidance and a variety of models are in use. The experimental evidence for BFPS in developed countries is mixed and traditional methods of systematic review are ill-equipped to explore heterogeneity, complexity, and context influences on effectiveness. This review aimed to enhance learning from the experimental evidence base for one-to-one BFPS intervention. Principles of realist review were applied to intervention case studies associated with published experimental studies. The review aimed (a) to explore heterogeneity in theoretical underpinnings and intervention design for one-to-one BFPS intervention; (b) inform design decisions by identifying transferable lessons developed from cross-case comparison of context-mechanism-outcome relationships; and (c) inform evaluation design by identifying context-mechanism-outcome relationships associated with experimental conditions. Findings highlighted poor attention to intervention theory and considerable heterogeneity in BFPS intervention design. Transferable mid-range theories to inform design emerged, which could be grouped into seven categories: (a) congruence with local infant feeding norms, (b) integration with the existing system of health care, (c) overcoming practical and emotional barriers to access, (d) ensuring friendly, competent, and proactive peers, (e) facilitating authentic peer-mother interactions, (f) motivating peers to ensure positive within-intervention amplification, and (g) ensuring positive legacy and maintenance of gains. There is a need to integrate realist principles into evaluation design to improve our understanding of what forms of BFPS work, for whom and under what circumstances. © 2017 John Wiley & Sons Ltd.

Knowledge synthesis with maps of neural connectivity.

PubMed

Tallis, Marcelo; Thompson, Richard; Russ, Thomas A; Burns, Gully A P C

2011-01-01

This paper describes software for neuroanatomical knowledge synthesis based on neural connectivity data. This software supports a mature methodology developed since the early 1990s. Over this time, the Swanson laboratory at USC has generated an account of the neural connectivity of the sub-structures of the hypothalamus, amygdala, septum, hippocampus, and bed nucleus of the stria terminalis. This is based on neuroanatomical data maps drawn into a standard brain atlas by experts. In earlier work, we presented an application for visualizing and comparing anatomical macro connections using the Swanson third edition atlas as a framework for accurate registration. Here we describe major improvements to the NeuARt application based on the incorporation of a knowledge representation of experimental design. We also present improvements in the interface and features of the data mapping components within a unified web-application. As a step toward developing an accurate sub-regional account of neural connectivity, we provide navigational access between the data maps and a semantic representation of area-to-area connections that they support. We do so based on an approach called "Knowledge Engineering from Experimental Design" (KEfED) model that is based on experimental variables. We have extended the underlying KEfED representation of tract-tracing experiments by incorporating the definition of a neuronanatomical data map as a measurement variable in the study design. This paper describes the software design of a web-application that allows anatomical data sets to be described within a standard experimental context and thus indexed by non-spatial experimental design features.

Experimental Evaluation of Turning Vane Designs for High-speed and Coupled Fan-drive Corners of 0.1-scale Model of NASA Lewis Research Center's Proposed Altitude Wind Tunnel

NASA Technical Reports Server (NTRS)

Gelder, Thomas F.; Moore, Royce D.; Shyne, Rickey J.; Boldman, Donald R.

1987-01-01

Two turning vane designs were experimentally evaluated for the fan-drive corner (corner 2) coupled to an upstream diffuser and the high-speed corner (corner 1) of the 0.1 scale model of NASA Lewis Research Center's proposed Altitude Wind Tunnel. For corner 2 both a controlled-diffusion vane design (vane A4) and a circular-arc vane design (vane B) were studied. The corner 2 total pressure loss coefficient was about 0.12 with either vane design. This was about 25 percent less loss than when corner 2 was tested alone. Although the vane A4 design has the advantage of 20 percent fewer vanes than the vane B design, its vane shape is more complex. The effects of simulated inlet flow distortion on the overall losses for corner 1 or 2 were small.

Improving Children's Problem Eating and Mealtime Behaviours: An Evaluative Study of a Single Session Parent Education Programme

ERIC Educational Resources Information Center

Fraser, Kim; Wallis, Marianne; St. John, Winsome

2004-01-01

Objective: To evaluate the effectiveness of a "single session" group, early intervention, multidisciplinary, education programme (entitled the "Fun not Fuss with Food" group programme) designed to improve children's problem eating and mealtime behaviours. Design: A quasi-experimental time-series design incorporating data…

Integration of CFD and Experimental Results at VKI in Low-Speed Aerodynamic Design

DTIC Science & Technology

2007-06-01

erosion in wind tunnel behind the building Today, almost all modern Antartic stations have undergone aerodynamic studies at different stages of design...2] J. Sanz Rodrigo, C. Gorle, J. van Beeck, P. Planquart: Aerodynamic Design of the Princess Elizabeth Antartic Research Station, 17th

Effects of floor location on response of composite fuselage frames

NASA Technical Reports Server (NTRS)

Carden, Huey D.; Jones, Lisa E.; Fasanella, Edwin L.

1992-01-01

Experimental and analytical results are presented which show the effect of floor placement on the structural response and strength of circular fuselage frames constructed of graphite-epoxy composite material. The research was conducted to study the behavior of conventionally designed advanced composite aircraft components. To achieve desired new designs which incorporate improved energy absorption capabilities requires an understanding of how these conventional designs behave under crash type loadings. Data are presented on the static behavior of the composite structure through photographs of the frame specimen, experimental strain distributions, and through analytical data from composite structural models. An understanding of this behavior can aid the dynamist in predicting the crash behavior of these structures and may assist the designer in achieving improved designs for energy absorption and crash behavior of future structures.

Impact of care pathways for in-hospital management of COPD exacerbation: a systematic review.

PubMed

Lodewijckx, C; Sermeus, W; Panella, M; Deneckere, S; Leigheb, F; Decramer, M; Vanhaecht, K

2011-11-01

In-hospital management of COPD exacerbation is suboptimal, and outcomes are poor. Care pathways are a possible strategy for optimizing care processes and outcomes. The aim of the literature review was to explore characteristics of existing care pathways for in-hospital management of COPD exacerbations and to address their impact on performance of care processes, clinical outcomes, and team functioning. A literature search was conducted for articles published between 1990 and 2010 in the electronic databases of Medline, CINAHL, EMBASE, and Cochrane Library. Main inclusion criteria were (I) patients hospitalized for a COPD exacerbation; (II) implementation and evaluation of a care pathway; (III) report of original research, including experimental and quasi experimental designs, variance analysis, and interviews of professionals and patients about their perception on pathway effectiveness. Four studies with a quasi experimental design were included. Three studies used a pre-post test design; the fourth study was a non randomized controlled trial comparing an experimental group where patients were treated according to a care pathway with a control group where usual care was provided. The four studied care pathways were multidisciplinary structured care plans, outlining time-specific clinical interventions and responsibilities by discipline. Statistic analyses were rarely performed, and the trials used very divergent indicators to evaluate the impact of the care pathways. The studies described positive effects on blood sampling, daily weight measurement, arterial blood gas measurement, referral to rehabilitation, feelings of anxiety, length of stay, readmission, and in-hospital mortality. Research on COPD care pathways is very limited. The studies described few positive effects of the care pathways on diagnostic processes and on clinical outcomes. Though due to limited statistical analysis and weak design of the studies, the internal validity of results is limited. Therefore, based on these studies the impact of care pathways on COPD exacerbation is inconclusive. These findings indicate the need for properly designed research like a cluster randomized controlled trial to evaluate the impact of COPD care pathways on performance of care processes, clinical outcomes, and teamwork. Copyright © 2011 Elsevier Ltd. All rights reserved.

Comparing Pedagogies for Plastic Waste Management at University Level

ERIC Educational Resources Information Center

Yeung, Siu-Kit; So, Wing-Mui Winnie; Cheng, Nga-Yee Irene; Cheung, Tsz-Yan; Chow, Cheuk-Fai

2017-01-01

Purpose: This paper aims to compare the learning outcomes of gaming simulation and guided inquiry in sustainability education on plastic waste management. The current study targets the identification of success factors in these teaching approaches. Design/methodology/approach: This study used a quasi-experimental design with undergraduate…

Optimal Design for Regression Discontinuity Studies with Clustering

ERIC Educational Resources Information Center

Rhoads, Christopher; Dye, Charles

2014-01-01

Recent years have seen an increased interest in quantitative educational research studies that use random assignment (RA) to evaluate the causal impacts of educational interventions (Angrist, 2004). The multi-level structure of the public education system in the United States often leads to experimental designs where naturally occurring clusters…

Effectiveness of Using the iPad in Learning to Acquire the Mental and Performance Skills in Teaching Social Studies Curriculum

ERIC Educational Resources Information Center

Alajmi, Maadi Mahdi; Al-Hadiah, Hanan Abdullah

2017-01-01

This study aims to examine the effectiveness of using the iPad in learning to acquire the mental and performance skills in teaching the social studies. Using experimental design method, the study compared two groups: (a) experimental, taught using the iPad, and (b) control group, taught using the traditional learning without iPad. A total of 48…

Optimising reversed-phase liquid chromatographic separation of an acidic mixture on a monolithic stationary phase with the aid of response surface methodology and experimental design.

PubMed

Wang, Y; Harrison, M; Clark, B J

2006-02-10

An optimization strategy for the separation of an acidic mixture by employing a monolithic stationary phase is presented, with the aid of experimental design and response surface methodology (RSM). An orthogonal array design (OAD) OA(16) (2(15)) was used to choose the significant parameters for the optimization. The significant factors were optimized by using a central composite design (CCD) and the quadratic models between the dependent and the independent parameters were built. The mathematical models were tested on a number of simulated data set and had a coefficient of R(2) > 0.97 (n = 16). On applying the optimization strategy, the factor effects were visualized as three-dimensional (3D) response surfaces and contour plots. The optimal condition was achieved in less than 40 min by using the monolithic packing with the mobile phase of methanol/20 mM phosphate buffer pH 2.7 (25.5/74.5, v/v). The method showed good agreement between the experimental data and predictive value throughout the studied parameter space and were suitable for optimization studies on the monolithic stationary phase for acidic compounds.

Quiet Clean Short-Haul Experimental Engine (QCSEE). Preliminary analyses and design report, volume 2

NASA Technical Reports Server (NTRS)

1974-01-01

The experimental and flight propulsion systems are presented. The following areas are discussed: engine core and low pressure turbine design; bearings and seals design; controls and accessories design; nacelle aerodynamic design; nacelle mechanical design; weight; and aircraft systems design.

78 FR 79622 - Endangered and Threatened Species: Designation of a Nonessential Experimental Population of...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-31

... Experimental Population of Central Valley Spring-Run Chinook Salmon Below Friant Dam in the San Joaquin River..., the National Marine Fisheries Service (NMFS), designate a nonessential experimental population of... experimental population for particular activities inside the experimental population's geographic range and...

Digital Storytelling for Enhancing Student Academic Achievement, Critical Thinking, and Learning Motivation: A Year-Long Experimental Study

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…

Experimental design and reporting standards for improving the internal validity of pre-clinical studies in the field of pain: Consensus of the IMI-Europain consortium.

PubMed

Knopp, K L; Stenfors, C; Baastrup, C; Bannon, A W; Calvo, M; Caspani, O; Currie, G; Finnerup, N B; Huang, W; Kennedy, J D; Lefevre, I; Machin, I; Macleod, M; Rees, H; Rice, A S C; Rutten, K; Segerdahl, M; Serra, J; Wodarski, R; Berge, O-G; Treedef, R-D

2017-12-29

Background and aims Pain is a subjective experience, and as such, pre-clinical models of human pain are highly simplified representations of clinical features. These models are nevertheless critical for the delivery of novel analgesics for human pain, providing pharmacodynamic measurements of activity and, where possible, on-target confirmation of that activity. It has, however, been suggested that at least 50% of all pre-clinical data, independent of discipline, cannot be replicated. Additionally, the paucity of "negative" data in the public domain indicates a publication bias, and significantly impacts the interpretation of failed attempts to replicate published findings. Evidence suggests that systematic biases in experimental design and conduct and insufficiencies in reporting play significant roles in poor reproducibility across pre-clinical studies. It then follows that recommendations on how to improve these factors are warranted. Methods Members of Europain, a pain research consortium funded by the European Innovative Medicines Initiative (IMI), developed internal recommendations on how to improve the reliability of pre-clinical studies between laboratories. This guidance is focused on two aspects: experimental design and conduct, and study reporting. Results Minimum requirements for experimental design and conduct were agreed upon across the dimensions of animal characteristics, sample size calculations, inclusion and exclusion criteria, random allocation to groups, allocation concealment, and blinded assessment of outcome. Building upon the Animals in Research: Reportingin vivo Experiments (ARRIVE) guidelines, reporting standards were developed for pre-clinical studies of pain. These include specific recommendations for reporting on ethical issues, experimental design and conduct, and data analysis and interpretation. Key principles such as sample size calculation, a priori definition of a primary efficacy measure, randomization, allocation concealments, and blinding are discussed. In addition, considerations of how stress and normal rodent physiology impact outcome of analgesic drug studies are considered. Flow diagrams are standard requirements in all clinical trials, and flow diagrams for preclinical trials, which describe number of animals included/excluded, and reasons for exclusion are proposed. Creation of a trial registry for pre-clinical studies focused on drug development in order to estimate possible publication bias is discussed. Conclusions More systematic research is needed to analyze how inadequate internal validity and/or experimental bias may impact reproducibility across pre-clinical pain studies. Addressing the potential threats to internal validity and the sources of experimental biases, as well as increasing the transparency in reporting, are likely to improve preclinical research broadly by ensuring relevant progress is made in advancing the knowledge of chronic pain pathophysiology and identifying novel analgesics. Implications We are now disseminating these Europain processes for discussion in the wider pain research community. Any benefit from these guidelines will be dependent on acceptance and disciplined implementation across pre-clinical laboratories, funding agencies and journal editors, but it is anticipated that these guidelines will be a first step towards improving scientific rigor across the field of pre-clinical pain research.

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

Chen, S.S.; Zhu, S.; Cai, Y.

Motion-dependent magnetic forces are the key elements in the study of magnetically levitated vehicle (maglev) system dynamics. In the past, most maglev-system designs were based on a quasisteady-motion theory of magnetic forces. This report presents an experimental and analytical study that will enhance our understanding of the role of unsteady-motion-dependent magnetic forces and demonstrate an experimental technique that can be used to measure those unsteady magnetic forces directly. The experimental technique provides a useful tool to measure motion-dependent magnetic forces for the prediction and control of maglev systems.

Numerical and experimental hydrodynamic analysis of suction cup bio-logging tag designs for marine mammals

NASA Astrophysics Data System (ADS)

Murray, Mark; Shorter, Alex; Howle, Laurens; Johnson, Mark; Moore, Michael

2012-11-01

The improvement and miniaturization of sensing technologies has made bio-logging tags, utilized for the study of marine mammal behavior, more practical. These sophisticated sensing packages require a housing which protects the electronics from the environment and provides a means of attachment to the animal. The hydrodynamic forces on these housings can inadvertently remove the tag or adversely affect the behavior or energetics of the animal. A modification to the original design of a suction cup bio-logging tag housing was desired to minimize the adverse forces. In this work, hydrodynamic loading of two suction cup tag designs, original and modified designs, were analyzed using computational fluid dynamics (CFD) models and validated experimentally. Overall, the simulation and experimental results demonstrated that a tag housing that minimized geometric disruptions to the flow reduced drag forces, and that a tag housing with a small frontal cross-sectional area close to the attachment surface reduced lift forces. Preliminary results from experimental work with a common dolphin cadaver indicates that the suction cups used to attach the tags to the animal provide sufficient attachment force to resist failure at predicted drag and lift forces in 10 m/s flow.

A Simulation Study on the Performance of the Simple Difference and Covariance-Adjusted Scores in Randomized Experimental Designs.

PubMed

Petscher, Yaacov; Schatschneider, Christopher

2011-01-01

Research by Huck and McLean (1975) demonstrated that the covariance-adjusted score is more powerful than the simple difference score, yet recent reviews indicate researchers are equally likely to use either score type in two-wave randomized experimental designs. A Monte Carlo simulation was conducted to examine the conditions under which the simple difference and covariance-adjusted scores were more or less powerful to detect treatment effects when relaxing certain assumptions made by Huck and McLean (1975). Four factors were manipulated in the design including sample size, normality of the pretest and posttest distributions, the correlation between pretest and posttest, and posttest variance. A 5 × 5 × 4 × 3 mostly crossed design was run with 1,000 replications per condition, resulting in 226,000 unique samples. The gain score was nearly as powerful as the covariance-adjusted score when pretest and posttest variances were equal, and as powerful in fan-spread growth conditions; thus, under certain circumstances the gain score could be used in two-wave randomized experimental designs.

A Simulation Study on the Performance of the Simple Difference and Covariance-Adjusted Scores in Randomized Experimental Designs

PubMed Central

Petscher, Yaacov; Schatschneider, Christopher

2015-01-01

Research by Huck and McLean (1975) demonstrated that the covariance-adjusted score is more powerful than the simple difference score, yet recent reviews indicate researchers are equally likely to use either score type in two-wave randomized experimental designs. A Monte Carlo simulation was conducted to examine the conditions under which the simple difference and covariance-adjusted scores were more or less powerful to detect treatment effects when relaxing certain assumptions made by Huck and McLean (1975). Four factors were manipulated in the design including sample size, normality of the pretest and posttest distributions, the correlation between pretest and posttest, and posttest variance. A 5 × 5 × 4 × 3 mostly crossed design was run with 1,000 replications per condition, resulting in 226,000 unique samples. The gain score was nearly as powerful as the covariance-adjusted score when pretest and posttest variances were equal, and as powerful in fan-spread growth conditions; thus, under certain circumstances the gain score could be used in two-wave randomized experimental designs. PMID:26379310

Photocatalytic degradation using design of experiments: a review and example of the Congo red degradation.

PubMed

Sakkas, Vasilios A; Islam, Md Azharul; Stalikas, Constantine; Albanis, Triantafyllos A

2010-03-15

The use of chemometric methods such as response surface methodology (RSM) based on statistical design of experiments (DOEs) is becoming increasingly widespread in several sciences such as analytical chemistry, engineering and environmental chemistry. Applied catalysis, is certainly not the exception. It is clear that photocatalytic processes mated with chemometric experimental design play a crucial role in the ability of reaching the optimum of the catalytic reactions. The present article reviews the major applications of RSM in modern experimental design combined with photocatalytic degradation processes. Moreover, the theoretical principles and designs that enable to obtain a polynomial regression equation, which expresses the influence of process parameters on the response are thoroughly discussed. An original experimental work, the photocatalytic degradation of the dye Congo red (CR) using TiO(2) suspensions and H(2)O(2), in natural surface water (river water) is comprehensively described as a case study, in order to provide sufficient guidelines to deal with this subject, in a rational and integrated way. (c) 2009 Elsevier B.V. All rights reserved.

Modeling Improvements and Users Manual for Axial-flow Turbine Off-design Computer Code AXOD

NASA Technical Reports Server (NTRS)

Glassman, Arthur J.

1994-01-01

An axial-flow turbine off-design performance computer code used for preliminary studies of gas turbine systems was modified and calibrated based on the experimental performance of large aircraft-type turbines. The flow- and loss-model modifications and calibrations are presented in this report. Comparisons are made between computed performances and experimental data for seven turbines over wide ranges of speed and pressure ratio. This report also serves as the users manual for the revised code, which is named AXOD.

Definition of smolder experiments for Spacelab

NASA Technical Reports Server (NTRS)

Summerfield, M.; Messina, N. A.; Ingram, L. S.

1979-01-01

The feasibility of conducting experiments in space on smoldering combustion was studied to conceptually design specific smoldering experiments to be conducted in the Shuttle/Spacelab System. Design information for identified experiment critical components is provided. The analytical and experimental basis for conducting research on smoldering phenomena in space was established. Physical descriptions of the various competing processes pertaining to smoldering combustion were identified. The need for space research was defined based on limitations of existing knowledge and limitations of ground-based reduced-gravity experimental facilities.

Computer-based visual communication in aphasia.

PubMed

Steele, R D; Weinrich, M; Wertz, R T; Kleczewska, M K; Carlson, G S

1989-01-01

The authors describe their recently developed Computer-aided VIsual Communication (C-VIC) system, and report results of single-subject experimental designs probing its use with five chronic, severely impaired aphasic individuals. Studies replicate earlier results obtained with a non-computerized system, demonstrate patient competence with the computer implementation, extend the system's utility, and identify promising areas of application. Results of the single-subject experimental designs clarify patients' learning, generalization, and retention patterns, and highlight areas of performance difficulties. Future directions for the project are indicated.

Development and Validation of a Rubric for Diagnosing Students' Experimental Design Knowledge and Difficulties.

PubMed

Dasgupta, Annwesa P; Anderson, Trevor R; Pelaez, Nancy

2014-01-01

It is essential to teach students about experimental design, as this facilitates their deeper understanding of how most biological knowledge was generated and gives them tools to perform their own investigations. Despite the importance of this area, surprisingly little is known about what students actually learn from designing biological experiments. In this paper, we describe a rubric for experimental design (RED) that can be used to measure knowledge of and diagnose difficulties with experimental design. The development and validation of the RED was informed by a literature review and empirical analysis of undergraduate biology students' responses to three published assessments. Five areas of difficulty with experimental design were identified: the variable properties of an experimental subject; the manipulated variables; measurement of outcomes; accounting for variability; and the scope of inference appropriate for experimental findings. Our findings revealed that some difficulties, documented some 50 yr ago, still exist among our undergraduate students, while others remain poorly investigated. The RED shows great promise for diagnosing students' experimental design knowledge in lecture settings, laboratory courses, research internships, and course-based undergraduate research experiences. It also shows potential for guiding the development and selection of assessment and instructional activities that foster experimental design. © 2014 A. P. Dasgupta et al. CBE—Life Sciences Education © 2014 The American Society for Cell Biology. This article is distributed by The American Society for Cell Biology under license from the author(s). It is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Experimental study of separator effect and shift angle on crossflow wind turbine performance

NASA Astrophysics Data System (ADS)

Fahrudin, Tjahjana, Dominicus Danardono Dwi Prija; Santoso, Budi

2018-02-01

This paper present experimental test results of separator and shift angle influence on Crossflow vertical axis wind turbine. Modification by using a separator and shift angle is expected to improve the thrust on the blade so as to improve the efficiency. The design of the wind turbine is tested at different wind speeds. There are 2 variations of crossflow turbine design which will be analyzed using an experimental test scheme that is, 3 stage crossflow and 2 stage crossflow with the shift angle. Maximum power coefficient obtained as Cpmax = 0.13 at wind speed 4.05 m/s for 1 separator and Cpmax = 0.12 for 12° shear angle of wind speed 4.05 m/s. In this study, power characteristics of the crossflow rotor with separator and shift angle have been tested. The experimental data was collected by variation of 2 separator and shift angle 0°, 6°, 12° and wind speed 3.01 - 4.85 m/s.

Design, development, and evaluation of visual aids for communicating prescription drug instructions to nonliterate patients in rural Cameroon.

PubMed

Ngoh, L N; Shepherd, M D

1997-03-01

In this study, culturally sensitive visual aids designed to help convey drug information to nonliterate female adults who had a prescription for a solid oral dosage form of antibiotic medications were developed and evaluated. The researchers conceptualized the educational messages while a local artist produced the visual aids. Seventy-eight female ambulatory patients were evaluated for comprehension and compliance with antibiotic prescription instructions. The study was conducted in three health centers in Cameroon, West Africa and followed a pre-test, post-test, and follow-up format for three groups: two experimental, and one control. All participants were randomly assigned to either experimental or control groups, 26 patients to each group. Subjects in the experimental groups received visual aids alone or visual aids plus an Advanced Organizer. A comparison of the three groups showed that subjects in the experimental groups scored significantly higher than the control group in both the comprehension and compliance measures.

First-Principles Design of Novel Catalytic and Chemoresponsive Materials

NASA Astrophysics Data System (ADS)

Roling, Luke T.

An emerging trend in materials design is the use of computational chemistry tools to accelerate materials discovery and implementation. In particular, the parallel nature of computational models enables high-throughput screening approaches that would be laborious and time-consuming with experiments alone, and can be useful for identifying promising candidate materials for experimental synthesis and evaluation. Additionally, atomic-scale modeling allows researchers to obtain a detailed understanding of phenomena invisible to many current experimental techniques. In this thesis, we highlight mechanistic studies and successes in catalyst design for heterogeneous electrochemical reactions, discussing both anode and cathode chemistries. In particular, we evaluate the properties of a new class of Pd-Pt core-shell and hollow nanocatalysts toward the oxygen reduction reaction. We do not limit our study to electrochemical reactivity, but also consider these catalysts in a broader context by performing in-depth studies of their stability at elevated temperatures as well as investigating the mechanisms by which they are able to form. We also present fundamental surface science studies, investigating graphene formation and H2 dissociation, which are processes of both fundamental and practical interest in many catalytic applications. Finally, we extend our materials design paradigm outside the field of catalysis to develop and apply a model for the detection of small chemical analytes by chemoresponsive liquid crystals, and offer several predictions for improving the detection of small chemicals. A close connection between computation, synthesis, and experimental evaluation is essential to the work described herein, as computations are used to gain fundamental insight into experimental observations, and experiments and synthesis are in turn used to validate predictions of material activities from computational models.

Using clinical simulation centers to test design interventions: a pilot study of lighting and color modifications.

PubMed

Gray, Whitney Austin; Kesten, Karen S; Hurst, Stephen; Day, Tama Duffy; Anderko, Laura

2012-01-01

The aim of this pilot study was to test design interventions such as lighting, color, and spatial color patterning on nurses' stress, alertness, and satisfaction, and to provide an example of how clinical simulation centers can be used to conduct research. The application of evidence-based design research in healthcare settings requires a transdisciplinary approach. Integrating approaches from multiple fields in real-life settings often proves time consuming and experimentally difficult. However, forums for collaboration such as clinical simulation centers may offer a solution. In these settings, identical operating and patient rooms are used to deliver simulated patient care scenarios using automated mannequins. Two identical rooms were modified in the clinical simulation center. Nurses spent 30 minutes in each room performing simulated cardiac resuscitation. Subjective measures of nurses' stress, alertness, and satisfaction were collected and compared between settings and across time using matched-pair t-test analysis. Nurses reported feeling less stressed after exposure to the experimental room than nurses who were exposed to the control room (2.22, p = .03). Scores post-session indicated a significant reduction in stress and an increase in alertness after exposure to the experimental room as compared to the control room, with significance levels below .10. (Change in stress scores: 3.44, p = .069); (change in alertness scores: 3.6, p = .071). This study reinforces the use of validated survey tools to measure stress, alertness, and satisfaction. Results support human-centered design approaches by evaluating the effect on nurses in an experimental setting.

A Novel Analysis Method for Paired-Sample Microbial Ecology Experiments.

PubMed

Olesen, Scott W; Vora, Suhani; Techtmann, Stephen M; Fortney, Julian L; Bastidas-Oyanedel, Juan R; Rodríguez, Jorge; Hazen, Terry C; Alm, Eric J

2016-01-01

Many microbial ecology experiments use sequencing data to measure a community's response to an experimental treatment. In a common experimental design, two units, one control and one experimental, are sampled before and after the treatment is applied to the experimental unit. The four resulting samples contain information about the dynamics of organisms that respond to the treatment, but there are no analytical methods designed to extract exactly this type of information from this configuration of samples. Here we present an analytical method specifically designed to visualize and generate hypotheses about microbial community dynamics in experiments that have paired samples and few or no replicates. The method is based on the Poisson lognormal distribution, long studied in macroecology, which we found accurately models the abundance distribution of taxa counts from 16S rRNA surveys. To demonstrate the method's validity and potential, we analyzed an experiment that measured the effect of crude oil on ocean microbial communities in microcosm. Our method identified known oil degraders as well as two clades, Maricurvus and Rhodobacteraceae, that responded to amendment with oil but do not include known oil degraders. Our approach is sensitive to organisms that increased in abundance only in the experimental unit but less sensitive to organisms that increased in both control and experimental units, thus mitigating the role of "bottle effects".

78 FR 3381 - Endangered and Threatened Species: Designation of a Nonessential Experimental Population of...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-16

... Experimental Population of Central Valley Spring-Run Chinook Salmon Below Friant Dam in the San Joaquin River... Fisheries Service (NMFS), propose a rule to designate a nonessential experimental population of Central... nonessential experimental population for particular activities inside the experimental population's geographic...

Testing the Developmental Origins of Health and Disease Hypothesis for Psychopathology Using Family-Based Quasi-Experimental Designs

PubMed Central

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

Engineering Design Handbook. Army Weapon Systems Analysis. Part 2

DTIC Science & Technology

1979-10-01

EXPERIMENTAL DESIGN ............................... ............ 41-3 41-5 RESULTS OF THE ASARS lIX SIMULATIONS ........................... 41-4 41-6 LATIN...sciences and human factors engineering fields utilizing experimental methodology and multi-variable statistical techniques drawn from experimental ...randomly to grenades for the test design . The nine experimental types of hand grenades (first’ nine in Table 33-2) had a "pip" on their spherical

Effects of Cloze Instructional Approach on Senior Secondary School Students' Achievement in Igbo Language Reading Comprehension

ERIC Educational Resources Information Center

Eze, Nneka Justina

2015-01-01

This study assessed the effects of cloze instructional approach on senior secondary school students' achievement in Igbo language reading comprehension. The study utilized a quasi experimental research design of the pretest posttest non-equivalent control group design. The study was conducted in Abakaliki education zone of Ebonyi State of Nigeria.…

Effects of Concept Mapping Instruction Approach on Students' Achievement in Basic Science

ERIC Educational Resources Information Center

Ogonnaya, Ukpai Patricia; Okafor, Gabriel; Abonyi, Okechukwu S.; Ugama, J. O.

2016-01-01

The study investigated the effects of concept mapping on students' achievement in basic science. The study was carried out in Ebonyi State of Nigeria. The study employed a quasi-experimental design. Specifically the pretest posttest non-equivalent control group research design was used. The sample was 122 students selected from two secondary…