AN EVALUATION OF PRIMARY DATA-COLLECTION MODES IN AN ADDRESS-BASED SAMPLING DESIGN.

PubMed

Amaya, Ashley; Leclere, Felicia; Carris, Kari; Liao, Youlian

2015-01-01

As address-based sampling becomes increasingly popular for multimode surveys, researchers continue to refine data-collection best practices. While much work has been conducted to improve efficiency within a given mode, additional research is needed on how multimode designs can be optimized across modes. Previous research has not evaluated the consequences of mode sequencing on multimode mail and phone surveys, nor has significant research been conducted to evaluate mode sequencing on a variety of indicators beyond response rates. We conducted an experiment within the Racial and Ethnic Approaches to Community Health across the U.S. Risk Factor Survey (REACH U.S.) to evaluate two multimode case-flow designs: (1) phone followed by mail (phone-first) and (2) mail followed by phone (mail-first). We compared response rates, cost, timeliness, and data quality to identify differences across case-flow design. Because surveys often differ on the rarity of the target population, we also examined whether changes in the eligibility rate altered the choice of optimal case flow. Our results suggested that, on most metrics, the mail-first design was superior to the phone-first design. Compared with phone-first, mail-first achieved a higher yield rate at a lower cost with equivalent data quality. While the phone-first design initially achieved more interviews compared to the mail-first design, over time the mail-first design surpassed it and obtained the greatest number of interviews.

Combination of a Flipped Classroom Format and a Virtual Patient Case to Enhance Active Learning in a Required Therapeutics Course

PubMed Central

Lichvar, Alicia Beth; Hedges, Ashley; Benedict, Neal J.

2016-01-01

Objective. To design and evaluate the integration of a virtual patient activity in a required therapeutics course already using a flipped-classroom teaching format. Design. A narrative-branched, dynamic virtual-patient case was designed to replace the static written cases that students worked through during the class, which was dedicated to teaching the complications of liver disease. Students completed pre- and posttests before and after completing the virtual patient case. Examination scores were compared to those in the previous year. Assessment. Students’ posttest scores were higher compared to pretest scores (33% vs 50%). Overall median examination scores were higher compared to the historical control group (70% vs 80%), as well as scores on questions assessing higher-level learning (67% vs 83%). A majority of students (68%) felt the virtual patient helped them apply knowledge gained in the pre-class video lecture. Students preferred this strategy to usual in-class activities (33%) or indicated it was of equal value (37%). Conclusion. The combination of a pre-class video lecture with an in-class virtual patient case is an effective active-learning strategy. PMID:28179724

Combination of a Flipped Classroom Format and a Virtual Patient Case to Enhance Active Learning in a Required Therapeutics Course.

PubMed

Lichvar, Alicia Beth; Hedges, Ashley; Benedict, Neal J; Donihi, Amy C

2016-12-25

Objective. To design and evaluate the integration of a virtual patient activity in a required therapeutics course already using a flipped-classroom teaching format. Design. A narrative-branched, dynamic virtual-patient case was designed to replace the static written cases that students worked through during the class, which was dedicated to teaching the complications of liver disease. Students completed pre- and posttests before and after completing the virtual patient case. Examination scores were compared to those in the previous year. Assessment. Students' posttest scores were higher compared to pretest scores (33% vs 50%). Overall median examination scores were higher compared to the historical control group (70% vs 80%), as well as scores on questions assessing higher-level learning (67% vs 83%). A majority of students (68%) felt the virtual patient helped them apply knowledge gained in the pre-class video lecture. Students preferred this strategy to usual in-class activities (33%) or indicated it was of equal value (37%). Conclusion. The combination of a pre-class video lecture with an in-class virtual patient case is an effective active-learning strategy.

Optimal design of studies of influenza transmission in households. I: case-ascertained studies.

PubMed

Klick, B; Leung, G M; Cowling, B J

2012-01-01

Case-ascertained household transmission studies, in which households including an 'index case' are recruited and followed up, are invaluable to understanding the epidemiology of influenza. We used a simulation approach parameterized with data from household transmission studies to evaluate alternative study designs. We compared studies that relied on self-reported illness in household contacts vs. studies that used home visits to collect swab specimens for virological confirmation of secondary infections, allowing for the trade-off between sample size vs. intensity of follow-up given a fixed budget. For studies estimating the secondary attack proportion, 2-3 follow-up visits with specimens collected from all members regardless of illness were optimal. However, for studies comparing secondary attack proportions between two or more groups, such as controlled intervention studies, designs with reactive home visits following illness reports in contacts were most powerful, while a design with one home visit optimally timed also performed well.

Reserve lithium-thionyl chloride battery for missile applications

NASA Astrophysics Data System (ADS)

Planchat, J. P.; Descroix, J. P.; Sarre, G.

A comparative performance study has been conducted for silver-zinc, thionyl chloride, and thermal batteries designed for such missile applications as ICBM guidance system power supplies. Attention is given to each of the three candidates' conformity to requirements concerning mechanical configuration, electrochemical design, electrolyte reservoir, external case, and gas generator. The silver-zinc and Li-SOCl2 candidates employ similar cell configurations and yield comparable performance. The thermal battery is found to be incapable of meeting battery case temperature-related requirements.

Comparing Architectural Styles for Service-Oriented Architectures - a REST vs. SOAP Case Study

NASA Astrophysics Data System (ADS)

Becker, Jörg; Matzner, Martin; Müller, Oliver

Two architectural styles are currently heavily discussed regarding the design of service-oriented architectures (SOA). Within this chapter we have compared those two alternative styles - the SOAP-style with procedural designs similar to remote procedure calls and the REST-style with loosely coupled services similar to resources of the World Wide Web. We introduce the case of a business network consisting of manufacturers and service providers of the electronics industry for deriving a set of requirements towards a specific SOA implementation. For each architectural style we present a concrete SOA design and evaluate it against the defined set of requirements.

Comparative study of control selection in a national population-based case-control study: Estimating risk of smoking on cancer deaths in Chinese men.

PubMed

Jiang, Jingmei; Liu, Boqi; Nasca, Philip C; Han, Wei; Zou, Xiaonong; Zeng, Xianjia; Tian, Xiaobing; Wu, Yanping; Zhao, Ping; Li, Junyao

2009-10-28

To assess the validation of a novel control selection design by comparing the consistency between the new design and a routine design in a large case-control study that was incorporated into a nationwide mortality survey in China. A nationwide mortality study was conducted during 1989-1991. Surviving spouses or other relatives of all adults who died during 1986-1988 provided detailed information about their own as well as the deceased person's smoking history. In this study, 130,079 males who died of various smoking-related cancers at age 35 or over were taken as cases, while 103,248 male surviving spouses (same age range with cases) of women who died during the same period and 49,331 males who died from causes other than those related to smoking were used as control group 1 and control group 2, respectively. Consistency in the results when comparing cases with each of the control groups was assessed. Consistency in the results was observed in the analyses using different control groups although cancer deaths varied with region and age. Equivalence could be ascertained using a 15% criterion in most cancer deaths which had high death rates in urban areas, but they were uncertain for most cancers in rural areas irrespective of whether the hypothesis testing showed significant differences or not. Sex-matched living spouse control design as an alternative control selection for a case-control study is valid and feasible, and the basic principles of the equivalence study are also supported by epidemiological survey data.

Learning in the Making: A Comparative Case Study of Three Makerspaces

ERIC Educational Resources Information Center

Sheridan, Kimberly M.; Halverson, Erica Rosenfeld; Litts, Breanne K.; Brahms, Lisa; Jacobs-Priebe, Lynette; Owens, Trevor

2014-01-01

Through a comparative case study, Sheridan and colleagues explore how makerspaces may function as learning environments. Drawing on field observations, interviews, and analysis of artifacts, videos, and other documents, the authors describe features of three makerspaces and how participants learn and develop through complex design and making…

Preliminary structural design of composite main rotor blades for minimum weight

NASA Technical Reports Server (NTRS)

Nixon, Mark W.

1987-01-01

A methodology is developed to perform minimum weight structural design for composite or metallic main rotor blades subject to aerodynamic performance, material strength, autorotation, and frequency constraints. The constraints and load cases are developed such that the final preliminary rotor design will satisfy U.S. Army military specifications, as well as take advantage of the versatility of composite materials. A minimum weight design is first developed subject to satisfying the aerodynamic performance, strength, and autorotation constraints for all static load cases. The minimum weight design is then dynamically tuned to avoid resonant frequencies occurring at the design rotor speed. With this methodology, three rotor blade designs were developed based on the geometry of the UH-60A Black Hawk titanium-spar rotor blade. The first design is of a single titanium-spar cross section, which is compared with the UH-60A Black Hawk rotor blade. The second and third designs use single and multiple graphite/epoxy-spar cross sections. These are compared with the titanium-spar design to demonstrate weight savings from use of this design methodology in conjunction with advanced composite materials.

Lessons learned: A comparative study of the integration experiences of Armenian and Palestinian refugees in Lebanon

DTIC Science & Technology

2017-06-01

design is based on two comparative case studies, examining Palestinian and Armenian refugees in Lebanon, respectively. These two cases are particularly...A COMPARATIVE STUDY OF THE INTEGRATION EXPERIENCES OF ARMENIAN AND PALESTINIAN REFUGEES IN LEBANON by Pascal Ghobeira June 2017 Thesis...REPORT DATE June 2017 3. REPORT TYPE AND DATES COVERED Master’s thesis 4. TITLE AND SUBTITLE LESSONS LEARNED: A COMPARATIVE STUDY OF THE

[Comparing case management care models for people with dementia and their caregivers: the design of the COMPAS study].

PubMed

van Hout, H P J; Macneil Vroomen, J L; Van Mierlo, L D; Meiland, F J M; Moll van Charante, E P; Joling, K J; van den Dungen, P; Dröes, R M; van der Horst, H E; de Rooij, S E J A

2014-04-01

Dementia care in The Netherlands is shifting from fragmented, ad hoc care to more coordinated and personalized care. Case management contributes to this shift. The linkage model and a combination of intensive case management and joint agency care models were selected based on their emerging prominence in The Netherlands. It is unclear if these different forms of case management are more effective than usual care in improving or preserving the functioning and well-being at the patient and caregiver level and at the societal cost. The objective of this article is to describe the design of a study comparing these two case management care models against usual care. Clinical and cost outcomes are investigated while care processes and the facilitators and barriers for implementation of these models are considered. Mixed methods include a prospective, observational, controlled, cohort study among persons with dementia and their primary informal caregiver in regions of The Netherlands with and without case management including a qualitative process evaluation. Community-dwelling individuals with a dementia diagnosis with an informal caregiver are included. The primary outcome measure is the Neuropsychiatric Inventory for the people with dementia and the General Health Questionnaire for their caregivers. Costs are measured from a societal perspective. Semi-structured interviews with stakeholders based on the theoretical model of adaptive implementation are planned. 521 pairs of persons with dementia and their primary informal caregiver were included and are followed over two years. In the linked model substantially more impeding factors for implementation were identified compared with the model. This article describes the design of an evaluation study of two case management models along with clinical and economic data from persons with dementia and caregivers. The impeding and facilitating factors differed substantially between the two models. Further results on cost-effectiveness are expected by the beginning of 2015. This is a Dutch adaptation of MacNeil Vroomen et al., Comparing Dutch case management care models for people with dementia and their caregivers: The design of the COMPAS study.

Clinical Research Methodology 2: Observational Clinical Research.

PubMed

Sessler, Daniel I; Imrey, Peter B

2015-10-01

Case-control and cohort studies are invaluable research tools and provide the strongest feasible research designs for addressing some questions. Case-control studies usually involve retrospective data collection. Cohort studies can involve retrospective, ambidirectional, or prospective data collection. Observational studies are subject to errors attributable to selection bias, confounding, measurement bias, and reverse causation-in addition to errors of chance. Confounding can be statistically controlled to the extent that potential factors are known and accurately measured, but, in practice, bias and unknown confounders usually remain additional potential sources of error, often of unknown magnitude and clinical impact. Causality-the most clinically useful relation between exposure and outcome-can rarely be definitively determined from observational studies because intentional, controlled manipulations of exposures are not involved. In this article, we review several types of observational clinical research: case series, comparative case-control and cohort studies, and hybrid designs in which case-control analyses are performed on selected members of cohorts. We also discuss the analytic issues that arise when groups to be compared in an observational study, such as patients receiving different therapies, are not comparable in other respects.

A comparison of Cox and logistic regression for use in genome-wide association studies of cohort and case-cohort design.

PubMed

Staley, James R; Jones, Edmund; Kaptoge, Stephen; Butterworth, Adam S; Sweeting, Michael J; Wood, Angela M; Howson, Joanna M M

2017-06-01

Logistic regression is often used instead of Cox regression to analyse genome-wide association studies (GWAS) of single-nucleotide polymorphisms (SNPs) and disease outcomes with cohort and case-cohort designs, as it is less computationally expensive. Although Cox and logistic regression models have been compared previously in cohort studies, this work does not completely cover the GWAS setting nor extend to the case-cohort study design. Here, we evaluated Cox and logistic regression applied to cohort and case-cohort genetic association studies using simulated data and genetic data from the EPIC-CVD study. In the cohort setting, there was a modest improvement in power to detect SNP-disease associations using Cox regression compared with logistic regression, which increased as the disease incidence increased. In contrast, logistic regression had more power than (Prentice weighted) Cox regression in the case-cohort setting. Logistic regression yielded inflated effect estimates (assuming the hazard ratio is the underlying measure of association) for both study designs, especially for SNPs with greater effect on disease. Given logistic regression is substantially more computationally efficient than Cox regression in both settings, we propose a two-step approach to GWAS in cohort and case-cohort studies. First to analyse all SNPs with logistic regression to identify associated variants below a pre-defined P-value threshold, and second to fit Cox regression (appropriately weighted in case-cohort studies) to those identified SNPs to ensure accurate estimation of association with disease.

Single-case experimental design yielded an effect estimate corresponding to a randomized controlled trial.

PubMed

Shadish, William R; Rindskopf, David M; Boyajian, Jonathan G

2016-08-01

We reanalyzed data from a previous randomized crossover design that administered high or low doses of intravenous immunoglobulin (IgG) to 12 patients with hypogammaglobulinaemia over 12 time points, with crossover after time 6. The objective was to see if results corresponded when analyzed as a set of single-case experimental designs vs. as a usual randomized controlled trial (RCT). Two blinded statisticians independently analyzed results. One analyzed the RCT comparing mean outcomes of group A (high dose IgG) to group B (low dose IgG) at the usual trial end point (time 6 in this case). The other analyzed all 12 time points for the group B patients as six single-case experimental designs analyzed together in a Bayesian nonlinear framework. In the randomized trial, group A [M = 794.93; standard deviation (SD) = 90.48] had significantly higher serum IgG levels at time six than group B (M = 283.89; SD = 71.10) (t = 10.88; df = 10; P < 0.001), yielding a mean difference of MD = 511.05 [standard error (SE) = 46.98]. For the single-case experimental designs, the effect from an intrinsically nonlinear regression was also significant and comparable in size with overlapping confidence intervals: MD = 495.00, SE = 54.41, and t = 495.00/54.41 = 9.10. Subsequent exploratory analyses indicated that how trend was modeled made a difference to these conclusions. The results of single-case experimental designs accurately approximated results from an RCT, although more work is needed to understand the conditions under which this holds. Copyright © 2016 Elsevier Inc. All rights reserved.

Science through Engineering in Elementary School: Comparing Three Enactments of an Engineering-Design-Based Curriculum on the Science of Sound

ERIC Educational Resources Information Center

Wendell, Kristen Bethke

2011-01-01

This research illustrates how varying enactments of an engineering-design-based science curriculum shaped the development of students' domain-specific scientific ideas and practices. In this comparative case study rooted in the analytical perspectives of activity theory and learning environments, student and teacher participants in three…

Design-Comparable Effect Sizes in Multiple Baseline Designs: A General Modeling Framework

ERIC Educational Resources Information Center

Pustejovsky, James E.; Hedges, Larry V.; Shadish, William R.

2014-01-01

In single-case research, the multiple baseline design is a widely used approach for evaluating the effects of interventions on individuals. Multiple baseline designs involve repeated measurement of outcomes over time and the controlled introduction of a treatment at different times for different individuals. This article outlines a general…

The risk of acute liver injury among users of antibiotic medications: a comparison of case-only studies.

PubMed

Brauer, Ruth; Ruigómez, Ana; Klungel, Olaf; Reynolds, Robert; Feudjo Tepie, Maurille; Smeeth, Liam; Douglas, Ian

2016-03-01

The aims of this study were two-fold: (i) to investigate the effect of exposure to antibiotic agents on the risk of acute liver injury using a self-controlled case series and case-crossover study and (ii) to compare the results between the case-only studies. For the self-controlled case series study relative incidence ratios (IRR) were calculated by dividing the rate of acute liver injury experienced during patients' periods of exposure to antibiotics to patients' rate of events during non-exposed time using conditional Poisson regression. For the case-crossover analysis we calculated Odds Ratios (OR) using conditional logistic regression by comparing exposure during 14- and 30-day risk windows with exposure during control moments. Using the self-controlled case series approach, the IRR was highest during the first 7 days after receipt of a prescription (10.01, 95% CI 6.59-15.18). Omitting post-exposure washout periods lowered the IRR to 7.2. The highest estimate in the case-crossover analysis was found when two 30-day control periods 1 year prior to the 30-day ALI risk period were retained in the analysis: OR = 6.5 (95% CI, 3.95-10.71). The lowest estimate was found when exposure in the 14-day risk period was compared to exposure in four consecutive 14-day control periods immediately prior to the risk period (OR = 3.05, 95% CI, 2.06-4.53). An increased relative risk of acute liver injury was consistently observed using both self-controlled case series and case-crossover designs. Case-only designs can be used as a viable alternative study design to study the risk of acute liver injury, albeit with some limitations. © 2015 The Authors Pharmacoepidemiology and Drug Safety Published by John Wiley & Sons Ltd.

Online Case-Based Discussions: Examining Coverage of the Afforded Problem Space

ERIC Educational Resources Information Center

Ertmer, Peggy A.; Koehler, Adrie A.

2014-01-01

Case studies hold great potential for engaging students in disciplinary content. However, little is known about the extent to which students actually cover the problem space afforded by a particular case study. In this research, we compared the problem space afforded by an instructional design case study with the actual content covered by 16…

Proton pump inhibitors and the risk of pneumonia: a comparison of cohort and self-controlled case series designs

PubMed Central

2013-01-01

Background To compare the results of a new-user cohort study design and the self-controlled case series (SCCS) design using the risk of hospitalisation for pneumonia in those dispensed proton pump inhibitors compared to those unexposed as a case study. Methods The Australian Government Department of Veterans’ Affairs administrative claims database was used. Exposure to proton pump inhibitors and hospitalisations for pneumonia were identified over a 4 year study period 01 Jul 2007 -30 Jun 2011. The same inclusion and exclusion criteria were applied to both studies, however, the SCCS study included subjects with a least one hospitalisation for pneumonia. Results There were 105,467 subjects included in the cohort study and 6775 in the SCCS. Both studies showed an increased risk of hospitalisations for pneumonia in the three defined risk periods following initiation of proton pump inhibitors compared to baseline. With the highest risk in the first 1 to 7 days (Cohort RR, 3.24; 95% CI (2.50, 4.19): SCCS: RR, 3.07; 95% CI (2.69, 3.50)). Conclusions This study has shown that the self-controlled case series method produces similar risk estimates to a new-users cohort study design when applied to the association of proton pump inhibitors and pneumonia. Exposure to a proton pump inhibitor increases the likelihood of being admitted to hospital for pneumonia, with the risk highest in the first week of treatment. PMID:23800078

On Problem of Synthesis of Control System for Quadrocopter

NASA Astrophysics Data System (ADS)

Larin, V. B.; Tunik, A. A.

2017-05-01

An algorithm for designing a control for a quadrocopter is given. Two cases of control of the horizontal motion of a vehicle are considered. Terminal location is given in one case, and cruise speed is given in the other case. The results are compared with those obtained by other authors

Naturally-Emerging Technology-Based Leadership Roles in Three Independent Schools: A Social Network-Based Case Study Using Fuzzy Set Qualitative Comparative Analysis

ERIC Educational Resources Information Center

Velastegui, Pamela J.

2013-01-01

This hypothesis-generating case study investigates the naturally emerging roles of technology brokers and technology leaders in three independent schools in New York involving 92 school educators. A multiple and mixed method design utilizing Social Network Analysis (SNA) and fuzzy set Qualitative Comparative Analysis (FSQCA) involved gathering…

Performance Comparison of Optimized Designs of Francis Turbines Exposed to Sediment Erosion in various Operating Conditions

NASA Astrophysics Data System (ADS)

Shrestha, K. P.; Chitrakar, S.; Thapa, B.; Dahlhaug, O. G.

2018-06-01

Erosion on hydro turbine mostly depends on impingement velocity, angle of impact, concentration, shape, size and distribution of erodent particle and substrate material. In the case of Francis turbines, the sediment particles tend to erode more in the off-designed conditions than at the best efficiency point. Previous studies focused on the optimized runner blade design to reduce erosion at the designed flow. However, the effect of the change in the design on other operating conditions was not studied. This paper demonstrates the performance of optimized Francis turbine exposed to sediment erosion in various operating conditions. Comparative study has been carryout among the five different shapes of runner, different set of guide vane and stay vane angles. The effect of erosion is studied in terms of average erosion density rate on optimized design Francis runner with Lagrangian particle tracking method in CFD analysis. The numerical sensitivity of the results are investigated by comparing two turbulence models. Numerical results are validated from the velocity measurements carried out in the actual turbine. Results show that runner blades are susceptible to more erosion at part load conditions compared to BEP, whereas for the case of guide vanes, more erosion occurs at full load conditions. Out of the five shapes compared, Shape 5 provides an optimum combination of efficiency and erosion on the studied operating conditions.

The Validity of the Comparative Interrupted Time Series Design for Evaluating the Effect of School-Level Interventions.

PubMed

Jacob, Robin; Somers, Marie-Andree; Zhu, Pei; Bloom, Howard

2016-06-01

In this article, we examine whether a well-executed comparative interrupted time series (CITS) design can produce valid inferences about the effectiveness of a school-level intervention. This article also explores the trade-off between bias reduction and precision loss across different methods of selecting comparison groups for the CITS design and assesses whether choosing matched comparison schools based only on preintervention test scores is sufficient to produce internally valid impact estimates. We conduct a validation study of the CITS design based on the federal Reading First program as implemented in one state using results from a regression discontinuity design as a causal benchmark. Our results contribute to the growing base of evidence regarding the validity of nonexperimental designs. We demonstrate that the CITS design can, in our example, produce internally valid estimates of program impacts when multiple years of preintervention outcome data (test scores in the present case) are available and when a set of reasonable criteria are used to select comparison organizations (schools in the present case). © The Author(s) 2016.

The impact of domain knowledge on structured data collection and templated note design.

PubMed

Windle, T; McClay, J C; Windle, J R

2013-01-01

The objective of this case report is to evaluate the importance of specialized domain knowledge when designing and using structured templated notes in a clinical environment. To analyze the impact of specialization on structured note generation we compared notes generated for three scenarios: 1) We compared the templated history of present illness (HPI) for patients presenting with a dermatology concern to the dermatologist versus the emergency department. 2) We compared the evaluation of chest pain by ED physicians versus cardiologists. 3) Finally, we compared the data elements asked for in the evaluation of the gastrointestinal system between cardiologists and the liver transplant service (LTS). We used the SNOMED CT representation via BioPortal to evaluate specificity and grouping between data elements and specialized physician groups. We found few similarities in structured data elements designed by and for the specific physician groups. The distinctness represented both differences in granularity as well as fundamental differences in data elements requested. When compared to ED physicians, dermatologists had different and more granular elements while cardiologists requested much more granular data. Comparing cardiologists and LTS, there were differences in the data elements requested. This case study supports the importance of domain knowledge in EHR design and implementation. That different specialities should want and use different information is well supported by cognitive science literature. Despite this, it is rare for domain knowledge to be considered in EHR implementation. Physicians with correct domain knowledge should be involved in the design process of templated notes.

Collaboration between Industrial Designers and Design Engineers - Comparing the Understanding of Design Intent.

PubMed

Laursen, Esben Skov; Møller, Louise

2015-01-01

This paper describes a case study comparing the understanding of design intent between industrial designers and design engineers. The study is based on the hypothesis that it is not all aspects of the design intent that are equally difficult to share between industrial designers and design engineers in the product development process. The study builds on five semi-structured interviews, where two industrial designers and three design engineers were interviewed about different aspects of the design intent. Based on our results, there seem to be indications that the more complex and abstract elements of industrial design knowledge such as the meaning, semantics, values, emotions and social aspects of the product are less shared by the design engineers. Moreover, the results also indicate that the different aspects of the design intent are perceived separately, rather than as part of a whole by the design engineers. The connection between the different aspects of the design intent is not shared between the industrial designer and design engineer making the shared knowledge less meaningful to the design engineers. The results of this study cannot be claimed to be conclusive due to the limited empirical material. Further investigation and analytically richer data are required in order to verify and broaden the findings. More case studies have therefore been planned in order to understand the area better.

Impact of Web-based Case Conferencing on Cancer Genetics Training Outcomes for Community-based Clinicians

PubMed Central

Blazer, Kathleen R.; Christie, Christina; Uman, Gwen; Weitzel, Jeffrey N.

2013-01-01

Introduction Technology and market forces are driving the demand for cancer risk assessment services in the community setting, where few clinicians are trained to order and interpret predictive genetic tests. City of Hope conducts a three-phase course in genetic cancer risk assessment (GCRA) for community-based clinicians, comprised of distance didactics, face-to-face workshops and 12 months of professional development. As designed, the course cannot meet increasing demands for GCRA training. Action research identified face-to-face workshops as a barrier to increasing course capacity. This study compared the learning effectiveness of Web-based case conferencing to face-to-face training. Methods A quasi-experimental design compared pre-post knowledge, skills and professional self-efficacy outcomes from 2009-2010 course cohorts (n=96). The intervention group (n=52) engaged in Web-based case conferences during distance learning; the comparison group (n=44) participated in the course as originally designed. Results Both groups and all practice disciplines demonstrated significant pre-to-post increases on all measures. Knowledge increases were higher for the intervention group (p < .015); skills and self-efficacy increases were comparable between groups (p < .33 and p < .30, respectively). Discussion Findings support the learning utility of Web-based case conferencing. Further studies may inform the development of tools to assess the impact of Web-based case conferencing on practice change and patient outcomes, in alignment with the highest standards of continuing professional development. PMID:22328115

The ACGME case log: General surgery resident experience in pediatric surgery

PubMed Central

Gow, Kenneth W.; Drake, F. Thurston; Aarabi, Shahram; Waldhausen, John H.

2014-01-01

Background General surgery (GS) residents in ACGME programs log cases performed during their residency. We reviewed designated pediatric surgery (PS) cases to assess for changes in performed cases over time. Methods The ACGME case logs for graduating GS residents were reviewed from academic year (AY) 1989–1990 to 2010–2011 for designated pediatric cases. Overall and designated PS cases were analyzed. Data were combined into five blocks: Period I (AY1989–90 to AY1993–94), Period II (AY1994–95 to AY1998–99), Period III (AY1999–00 to AY2002–03), Period IV (AY2003–04 to AY2006–07), and Period V (AY2007–08 to AY2010–11). Periods IV and V were delineated by implementation of duty hour restrictions. Student t-tests compared averages among the time periods with significance at P < .05. Results Overall GS case load remained relatively stable. Of total cases, PS cases accounted for 5.4% in Period I and 3.7% in Period V. Designated pediatric cases declined for each period from an average of 47.7 in Period I to 33.8 in Period V. These changes are due to a decline in hernia repairs, which account for half of cases. All other cases contributed only minimally to the pediatric cases. The only laparoscopic cases in the database were anti-reflux procedures, which increased over time. Conclusions GS residents perform a diminishing number of designated PS cases. This decline occurred before the onset of work-hour restrictions. These changes have implications on the capabilities of the current graduating workforce. However, the case log does not reflect all cases trainees may be exposed to, so revision of this list is recommended. PMID:23932601

Single-case synthesis tools I: Comparing tools to evaluate SCD quality and rigor.

PubMed

Zimmerman, Kathleen N; Ledford, Jennifer R; Severini, Katherine E; Pustejovsky, James E; Barton, Erin E; Lloyd, Blair P

2018-03-03

Tools for evaluating the quality and rigor of single case research designs (SCD) are often used when conducting SCD syntheses. Preferred components include evaluations of design features related to the internal validity of SCD to obtain quality and/or rigor ratings. Three tools for evaluating the quality and rigor of SCD (Council for Exceptional Children, What Works Clearinghouse, and Single-Case Analysis and Design Framework) were compared to determine if conclusions regarding the effectiveness of antecedent sensory-based interventions for young children changed based on choice of quality evaluation tool. Evaluation of SCD quality differed across tools, suggesting selection of quality evaluation tools impacts evaluation findings. Suggestions for selecting an appropriate quality and rigor assessment tool are provided and across-tool conclusions are drawn regarding the quality and rigor of studies. Finally, authors provide guidance for using quality evaluations in conjunction with outcome analyses when conducting syntheses of interventions evaluated in the context of SCD. Copyright © 2018 Elsevier Ltd. All rights reserved.

Using the entire history in the analysis of nested case cohort samples.

PubMed

Rivera, C L; Lumley, T

2016-08-15

Countermatching designs can provide more efficient estimates than simple matching or case-cohort designs in certain situations such as when good surrogate variables for an exposure of interest are available. We extend pseudolikelihood estimation for the Cox model under countermatching designs to models where time-varying covariates are considered. We also implement pseudolikelihood with calibrated weights to improve efficiency in nested case-control designs in the presence of time-varying variables. A simulation study is carried out, which considers four different scenarios including a binary time-dependent variable, a continuous time-dependent variable, and the case including interactions in each. Simulation results show that pseudolikelihood with calibrated weights under countermatching offers large gains in efficiency if compared to case-cohort. Pseudolikelihood with calibrated weights yielded more efficient estimators than pseudolikelihood estimators. Additionally, estimators were more efficient under countermatching than under case-cohort for the situations considered. The methods are illustrated using the Colorado Plateau uranium miners cohort. Furthermore, we present a general method to generate survival times with time-varying covariates. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Associations of daily pediatric asthma emergency department visits with air pollution in Newark, NJ: utilizing time-series and case-crossover study designs.

PubMed

Gleason, Jessie A; Fagliano, Jerald A

2015-10-01

Asthma is one of the most common chronic diseases affecting children. This study assesses the associations of ozone and fine particulate matter (PM2.5) with pediatric emergency department visits in the urban environment of Newark, NJ. Two study designs were utilized and evaluated for usability. We obtained daily emergency department visits among children aged 3-17 years with a primary diagnosis of asthma during April to September for 2004-2007. Both a time-stratified case-crossover study design with bi-directional control sampling and a time-series study design were utilized. Lagged effects (1-d through 5-d lag, 3-d average, and 5-d average) of ozone and PM2.5 were explored and a dose-response analysis comparing the bottom 5th percentile of 3-d average lag ozone with each 5 percentile increase was performed. Associations of interquartile range increase in same-day ozone were similar between the time-series and case-crossover study designs (RR = 1.08, 95% CI 1.04-1.12) and (OR = 1.10, 95% CI 1.06-1.14), respectively. Similar associations were seen for 1-day lag and 3-day average lag ozone levels. PM2.5 was not associated with the outcome in either study design. Dose-response assessment indicated a statistically significant and increasing association around 50-55 ppb consistent for both study designs. Ozone was statistically positively associated with pediatric asthma ED visits in Newark, NJ. Our results were generally comparable across the time-series and case-crossover study designs, indicating both are useful to assess local air pollution impacts.

Hyperactivity of the default-mode network in first-episode, drug-naive schizophrenia at rest revealed by family-based case-control and traditional case-control designs.

PubMed

Guo, Wenbin; Liu, Feng; Chen, Jindong; Wu, Renrong; Li, Lehua; Zhang, Zhikun; Chen, Huafu; Zhao, Jingping

2017-03-01

Abnormal regional activity and functional connectivity of the default-mode network (DMN) have been reported in schizophrenia. However, previous studies may have been biased by unmatched case-control design. To limit such bias, the present study used both the family-based case-control design and the traditional case-control design to investigate abnormal regional activity of the DMN in patients with schizophrenia at rest.Twenty-eight first-episode, drug-naive patients with schizophrenia, 28 age-, sex-matched unaffected siblings of the patients (family-based controls, FBC), and 40 healthy controls (HC) underwent resting-state functional magnetic resonance imaging (fMRI) scans. The group-independent component analysis and fractional amplitude of low-frequency fluctuation (fALFF) methods were used to analyze the data.Patients with schizophrenia show increased fALFF in an overlapped region of the right superior medial prefrontal cortex (MPFC) relative to the FBC and the HC. Compared with the HC, the patients and the FBC exhibit increased fALFF in an overlapped region of the left posterior cingulate cortex/precuneus (PCC/PCu). Furthermore, the z values of the 2 overlapped regions can separate the patients from the FBC/HC, and separate the patients/FBC from the HC with relatively high sensitivity and specificity.Both the family-based case-control and traditional case-control designs reveal hyperactivity of the DMN in first-episode, drug-naive patients with paranoid schizophrenia, which highlights the importance of the DMN in the neurobiology of schizophrenia. Family-based case-control design can limit the confounding effects of environmental factors in schizophrenia. Combination of the family-based case-control and traditional case-control designs may be a viable option for the neuroimaging studies.

Fatigue Lifespan of Engine Box Influenced by Fan Blade Out

NASA Astrophysics Data System (ADS)

Qiu, Ju; Shi, Jingwei; Su, Huaizhong; Zhang, Jinling; Feng, Juan; Shi, Qian; Tian, Xiaoyu

2017-11-01

This provides precious experience and reliable reference data for future design. This paper introduces the analysis process of Fan-blade-out, and considers the effect of windmill load on the fatigue lifespan of the case. According to Extended Operations (ETOPS) in the airworthiness regulations, the fatigue crack of it is analyzed by the unbalanced rotor load, during FBO. Compared with the lifespan in normal work of the engine, this research provides valuable design experience and reliable reference data for the case design in the near future.

ED-WAVE tool design approach: Case of a textile wastewater treatment plant in Blantyre, Malawi

NASA Astrophysics Data System (ADS)

Chipofya, V.; Kraslawski, A.; Avramenko, Y.

The ED-WAVE tool is a PC based package for imparting training on wastewater treatment technologies. The system consists of four modules viz. Reference Library, Process Builder, Case Study Manager, and Treatment Adviser. The principles of case-based design and case-based reasoning as applied in the ED-WAVE tool are utilised in this paper to evaluate the design approach of the wastewater treatment plant at Mapeto David Whitehead & Sons (MDW&S) textile and garments factory, Blantyre, Malawi. The case being compared with MDW&S in the ED-WAVE tool is Textile Case 4 in Sri Lanka (2003). Equalisation, coagulation and rotating biological contactors is the sequencing of treatment units at Textile Case 4 in Sri Lanka. Screening, oxidation ditches and sedimentation is the sequencing of treatment units at MDW&S textile and garments factory. The study suggests that aerobic biological treatment is necessary in the treatment of wastewater from a textile and garments factory. MDW&S incorporates a sedimentation process which is necessary for the removal of settleable matter before the effluent is discharged to the municipal wastewater treatment plant. The study confirmed the practical use of the ED-WAVE tool in the design of wastewater treatment systems, where after encountering a new situation; already collected decision scenarios (cases) are invoked and modified in order to arrive at a particular design alternative. What is necessary, however, is to appropriately modify the case arrived at through the Case Study Manager in order to come up with a design appropriate to the local situation taking into account technical, socio-economic and environmental aspects.

Which design for which question? An exploration toward a translation table for comparative effectiveness research.

PubMed

Montori, Victor M; Kim, Simon P; Guyatt, Gordon H; Shah, Nilay D

2012-05-01

In this paper, we explore the relative value that different methods offer in answering some stereotypical comparative effectiveness research questions with the goal of informing development of a 'translation table'--a selection tool for choosing appropriate methods for specific comparative effectiveness research questions. This paper was written as a parallel effort to Greenfield and Kaplan (also in this volume) to support the endeavor described in the manuscript by Tunis et al. (also in this volume). Originally based on four cases, the current article has been shortened to two cases for the current discussion. These cases represent research priorities proposed to orient the work of the Patient-Centered Outcomes Research Institute, comparative clinical effectiveness and comparative health services.

User-only design to assess drug effectiveness in clinical practice: application to bisphosphonates and secondary prevention of fractures.

PubMed

Corrao, Giovanni; Ghirardi, Arianna; Segafredo, Giulia; Zambon, Antonella; Della Vedova, Gianluca; Lapi, Francesco; Cipriani, Francesco; Caputi, Achille; Vaccheri, Alberto; Gregori, Dario; Gesuita, Rosaria; Vestri, Annarita; Staniscia, Tommaso; Mazzaglia, Giampiero; Di Bari, Mauro

2014-08-01

Different strategies applicable to control for confounding by indication in observational studies were compared in a large population-based study regarding the effect of bisphosphonates (BPs) for secondary prevention of fractures. The cohort was drawn from healthcare utilization databases of 13 Italian territorial units. Patients aged 55 years or more who were hospitalized for fracture during 2003-2005 entered into the cohort. A nested case-control design was used to compare BPs use in cohort members who did (cases) and who did not experience (controls) a new fracture until 2007 (outcome). Three designs were employed: conventional-matching (D1 ), propensity score-matching (D2 ), and user-only (D3 ) designs. They differed for (i) cohort composition, restricted to patients who received BPs straight after cohort entry (D3 ); (ii) using propensity score for case-control matching (D2 ); and (iii) compared groups of BPs users versus no users (D1 and D2 ) and long-term versus short-term users (D3 ). Bisphosphonate users had odds ratios (95% confidence interval) of 1.20 (1.01 to 1.44) and 0.95 (0.74 to 1.24) by applying D1 and D2 designs, respectively. Statistical evidence that long-term BPs use protects the outcome onset with respect to short-term use was observed for user-only design (D3 ) being the corresponding odds ratio (95% confidence interval) 0.64 (0.44 to 0.93). User-only design yielded closer results to those seen in RCTs. This approach is one possible strategy to account for confounding by indication. Copyright © 2014 John Wiley & Sons, Ltd.

Optimal design of studies of influenza transmission in households. II: comparison between cohort and case-ascertained studies.

PubMed

Klick, B; Nishiura, H; Leung, G M; Cowling, B J

2014-04-01

Both case-ascertained household studies, in which households are recruited after an 'index case' is identified, and household cohort studies, where a household is enrolled before the start of the epidemic, may be used to test and estimate the protective effect of interventions used to prevent influenza transmission. A simulation approach parameterized with empirical data from household studies was used to evaluate and compare the statistical power of four study designs: a cohort study with routine virological testing of household contacts of infected index case, a cohort study where only household contacts with acute respiratory illness (ARI) are sampled for virological testing, a case-ascertained study with routine virological testing of household contacts, and a case-ascertained study where only household contacts with ARI are sampled for virological testing. We found that a case-ascertained study with ARI-triggered testing would be the most powerful design while a cohort design only testing household contacts with ARI was the least powerful. Sensitivity analysis demonstrated that these conclusions varied by model parameters including the serial interval and the risk of influenza virus infection from outside the household.

Meta-Analysis of Incremental Rehearsal Using Phi Coefficients to Compare Single-Case and Group Designs

ERIC Educational Resources Information Center

Burns, Matthew K.; Zaslofsky, Anne F.; Kanive, Rebecca; Parker, David C.

2012-01-01

The current study meta-analyzed single-case design (SCD) and group research regarding incremental rehearsal (IR). We used phi to meta-analyze data from 19 IR studies. Data from the SCD studies resulted in a nonoverlap of all pairs (NAP) score of 98.9% (95% CI = 97.6-100%), which resulted in a weighted phi of 0.77 (95% CI = 0.69-0.83). The group…

MARATHON Verification (MARV)

DTIC Science & Technology

2017-08-01

comparable with MARATHON 1 in terms of output. Rather, the MARATHON 2 verification cases were designed to ensure correct implementation of the new algorithms...DISCLAIMER The findings of this report are not to be construed as an official Department of the Army position, policy, or decision unless so designated by...for employment against demands. This study is a comparative verification of the functionality of MARATHON 4 (our newest implementation of MARATHON

29 CFR 2550.404a-5 - Fiduciary requirements for disclosure in participant-directed individual account plans.

Code of Federal Regulations, 2011 CFR

2011-07-01

... participants and beneficiaries pursuant to paragraph (d)(1) of this section. (2) Comparative format. (i... a chart or similar format that is designed to facilitate a comparison of such information for each... employer securities. In the case of designated investment alternatives designed to invest in, or primarily...

29 CFR 2550.404a-5 - Fiduciary requirements for disclosure in participant-directed individual account plans.

Code of Federal Regulations, 2012 CFR

2012-07-01

... participants and beneficiaries pursuant to paragraph (d)(1) of this section. (2) Comparative format. (i... a chart or similar format that is designed to facilitate a comparison of such information for each... employer securities. In the case of designated investment alternatives designed to invest in, or primarily...

29 CFR 2550.404a-5 - Fiduciary requirements for disclosure in participant-directed individual account plans.

Code of Federal Regulations, 2014 CFR

2014-07-01

... participants and beneficiaries pursuant to paragraph (d)(1) of this section. (2) Comparative format. (i... a chart or similar format that is designed to facilitate a comparison of such information for each... employer securities. In the case of designated investment alternatives designed to invest in, or primarily...

29 CFR 2550.404a-5 - Fiduciary requirements for disclosure in participant-directed individual account plans.

Code of Federal Regulations, 2013 CFR

2013-07-01

... participants and beneficiaries pursuant to paragraph (d)(1) of this section. (2) Comparative format. (i... a chart or similar format that is designed to facilitate a comparison of such information for each... employer securities. In the case of designated investment alternatives designed to invest in, or primarily...

Analytical considerations for study design

Treesearch

Barry R. Noon; William M. Block

1990-01-01

Studies of the foraging behaviors of birds have been largely descriptive and comparative. One might then expect studies with similar objectives to have similar study designs but that is not the case. Papers in this symposium that focused specifically on study design contain a diversity of biological perspectives. Similarly, there is no accord among statisticians on...

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'…

Case-control analysis in highway safety: Accounting for sites with multiple crashes.

PubMed

Gross, Frank

2013-12-01

There is an increased interest in the use of epidemiological methods in highway safety analysis. The case-control and cohort methods are commonly used in the epidemiological field to identify risk factors and quantify the risk or odds of disease given certain characteristics and factors related to an individual. This same concept can be applied to highway safety where the entity of interest is a roadway segment or intersection (rather than a person) and the risk factors of interest are the operational and geometric characteristics of a given roadway. One criticism of the use of these methods in highway safety is that they have not accounted for the difference between sites with single and multiple crashes. In the medical field, a disease either occurs or it does not; multiple occurrences are generally not an issue. In the highway safety field, it is necessary to evaluate the safety of a given site while accounting for multiple crashes. Otherwise, the analysis may underestimate the safety effects of a given factor. This paper explores the use of the case-control method in highway safety and two variations to account for sites with multiple crashes. Specifically, the paper presents two alternative methods for defining cases in a case-control study and compares the results in a case study. The first alternative defines a separate case for each crash in a given study period, thereby increasing the weight of the associated roadway characteristics in the analysis. The second alternative defines entire crash categories as cases (sites with one crash, sites with two crashes, etc.) and analyzes each group separately in comparison to sites with no crashes. The results are also compared to a "typical" case-control application, where the cases are simply defined as any entity that experiences at least one crash and controls are those entities without a crash in a given period. In a "typical" case-control design, the attributes associated with single-crash segments are weighted the same as the attributes of segments with multiple crashes. The results support the hypothesis that the "typical" case-control design may underestimate the safety effects of a given factor compared to methods that account for sites with multiple crashes. Compared to the first alternative case definition (where multiple crash segments represent multiple cases) the results from the "typical" case-control design are less pronounced (i.e., closer to unity). The second alternative (where case definitions are constructed for various crash categories and analyzed separately) provides further evidence that sites with single and multiple crashes should not be grouped together in a case-control analysis. This paper indicates a clear need to differentiate sites with single and multiple crashes in a case-control analysis. While the results suggest that sites with multiple crashes can be accounted for using a case-control design, further research is needed to determine the optimal method for addressing this issue. This paper provides a starting point for that research. Copyright © 2012 Elsevier Ltd. All rights reserved.

Teaching with the Case Study Method to Promote Active Learning in a Small Molecule Crystallography Course for Chemistry Students

ERIC Educational Resources Information Center

Campbell, Michael G.; Powers, Tamara M.; Zheng, Shao-Liang

2016-01-01

Implementing the case study method in a practical X-ray crystallography course designed for graduate or upper-level undergraduate chemistry students is described. Compared with a traditional lecture format, assigning small groups of students to examine literature case studies encourages more active engagement with the course material and…

The Effects of Discourses in Regional Contexts on the Development of Curriculum-Based Literacy Standards for Adolescents in Schooling: A Comparative Study of South Australia and Ontario

ERIC Educational Resources Information Center

Fenwick, Lisl

2017-01-01

This study analyses how discourses in regional contexts affect the development of curriculum-based literacy standards for adolescents in schooling. A comparative case-study research design enabled the influences of discourses at the regional level to be analysed. The case studies include the development of curricula to define a minimum literacy…

Robust blood-glucose control using Mathematica.

PubMed

Kovács, Levente; Paláncz, Béla; Benyó, Balázs; Török, László; Benyó, Zoltán

2006-01-01

A robust control design on frequency domain using Mathematica is presented for regularization of glucose level in type I diabetes persons under intensive care. The method originally proposed under Mathematica by Helton and Merino, --now with an improved disturbance rejection constraint inequality--is employed, using a three-state minimal patient model. The robustness of the resulted high-order linear controller is demonstrated by nonlinear closed loop simulation in state-space, in case of standard meal disturbances and is compared with H infinity design implemented with the mu-toolbox of Matlab. The controller designed with model parameters represented the most favorable plant dynamics from the point of view of control purposes, can operate properly even in case of parameter values of the worst-case scenario.

Strengthening the Regression Discontinuity Design Using Additional Design Elements: A Within-Study Comparison

ERIC Educational Resources Information Center

Wing, Coady; Cook, Thomas D.

2013-01-01

The sharp regression discontinuity design (RDD) has three key weaknesses compared to the randomized clinical trial (RCT). It has lower statistical power, it is more dependent on statistical modeling assumptions, and its treatment effect estimates are limited to the narrow subpopulation of cases immediately around the cutoff, which is rarely of…

Refining a Competency Model for Instructional Designers in the Context of Online Higher Education

ERIC Educational Resources Information Center

Park, Jae-Young; Luo, Heng

2017-01-01

This study investigates the instructional designers (IDs) competencies essential for the context of online higher education, and has selected an instruction design unit in a research university as a case of investigation. To identify and compare IDs competencies at organizational and individual levels, this study employed a mixed method to collect…

[Case-non case studies: Principles, methods, bias and interpretation].

PubMed

Faillie, Jean-Luc

2017-10-31

Case-non case studies belongs to the methods assessing drug safety by analyzing the disproportionality of notifications of adverse drug reactions in pharmacovigilance databases. Used for the first time in the 1980s, the last few decades have seen a significant increase in the use of this design. The principle of the case-non case study is to compare drug exposure in cases of a studied adverse reaction with that of cases of other reported adverse reactions and called "non cases". Results are presented in the form of a reporting odds ratio (ROR), the interpretation of which makes it possible to identify drug safety signals. This article describes the principle of the case-non case study, the method of calculating the ROR and its confidence interval, the different modalities of analysis and how to interpret its results with regard to the advantages and limitations of this design. Copyright © 2017 Société française de pharmacologie et de thérapeutique. Published by Elsevier Masson SAS. All rights reserved.

Alternative Education: A Comparative Case Study of the Behavior Modification Programs of Two Upstate South Carolina Alternative Schools for Youth Who Exhibit Behavior That Is Disruptive

ERIC Educational Resources Information Center

Scipio, Timothy Lamont

2013-01-01

This study examined behavior modification programs in schools designed to focus on discipline and that aim to reform disruptive behavior in students, usually over a limited period of time. This was a comparative case study of two type II alternative schools in the Upstate of South Carolina. The findings contributed to the research base regarding…

Comparing Single Case Design Overlap-Based Effect Size Metrics From Studies Examining Speech Generating Device Interventions

PubMed Central

Chen, Mo; Hyppa-Martin, Jolene K.; Reichle, Joe E.; Symons, Frank J.

2017-01-01

Meaningfully synthesizing single case experimental data from intervention studies comprised of individuals with low incidence conditions and generating effect size estimates remains challenging. Seven effect size metrics were compared for single case design (SCD) data focused on teaching speech generating device use to individuals with intellectual and developmental disabilities (IDD) with moderate to profound levels of impairment. The effect size metrics included percent of data points exceeding the median (PEM), percent of nonoverlapping data (PND), improvement rate difference (IRD), percent of all nonoverlapping data (PAND), Phi, nonoverlap of all pairs (NAP), and Taunovlap. Results showed that among the seven effect size metrics, PAND, Phi, IRD, and PND were more effective in quantifying intervention effects for the data sample (N = 285 phase or condition contrasts). Results are discussed with respect to issues concerning extracting and calculating effect sizes, visual analysis, and SCD intervention research in IDD. PMID:27119210

Toward instructional design principles: Inducing Faraday's law with contrasting cases

NASA Astrophysics Data System (ADS)

Kuo, Eric; Wieman, Carl E.

2016-06-01

Although physics education research (PER) has improved instructional practices, there are not agreed upon principles for designing effective instructional materials. Here, we illustrate how close comparison of instructional materials could support the development of such principles. Specifically, in discussion sections of a large, introductory physics course, a pair of studies compare two instructional strategies for teaching a physics concept: having students (i) explain a set of contrasting cases or (ii) apply and build on previously learned concepts. We compare these strategies for the teaching of Faraday's law, showing that explaining a set of related contrasting cases not only improves student performance on Faraday's law questions over building on a previously learned concept (i.e., Lorentz force), but also prepares students to better learn subsequent topics, such as Lenz's law. These differences persist to the final exam. We argue that early exposure to contrasting cases better focuses student attention on a key feature related to both concepts: change in magnetic flux. Importantly, the benefits of contrasting cases for both learning and enjoyment are enhanced for students who did not first attend a Faraday's law lecture, consistent with previous research suggesting that being told a solution can circumvent the benefits of its discovery. These studies illustrate an experimental approach for understanding how the structure of activities affects learning and performance outcomes, a first step toward design principles for effective instructional materials.

A cognitive framework to inform the design of professional development supporting teachers' classroom assessment of inquiry-based science

NASA Astrophysics Data System (ADS)

Matese, Gabrielle

Inquiry-based science places new demands on teachers for assessing students' growth, both of deep conceptual understanding as well as developing inquiry skills. In addition, new ideas about classroom assessment, such as the importance of formative assessment, are gaining currency. While we have ideas about what classroom assessment consistent with inquiry-based pedagogy might look like, and why it is necessary, we have little understanding of what it takes to implement it. That teachers face a challenge in doing so is well-documented. Researchers have noted that teachers attempting changes in classroom assessment often bring with them incompatible beliefs, knowledge, and practices. However, noting general incompatibility is insufficient to support addressing these issues through professional development. In response to this need, I initiated a research project to identify and describe in more detail the categories of beliefs, knowledge and skills that play an important role in inquiry-based science assessment practices. I created an assessment framework outlining specific categories of beliefs, knowledge, and skills affecting particular classroom assessment practices. I then used the framework to examine teachers' classroom assessment practices and to create comparative cases between three middle-school science teachers, highlighting how the different cognitive factors affect four particular assessment practices. The comparative cases demonstrate the framework's utility for analyzing and explicating teacher assessment practices. As a tool for analyzing and understanding teacher practice, the framework supports the design of professional development. To demonstrate the value of the framework, I draw on the comparative cases to identify implications for the design of professional development to support teachers' classroom assessment of inquiry-based science. In this dissertation I provide a brief overview of the framework and its rationale, present an example of the comparative case studies demonstrating the application of the framework and what it reveals about the cognitive influences on teacher practice, and outline the resulting design implications for professional development. This research allows us to better understand the cognitive factors underlying classroom assessment in inquiry-based science, and to design professional development to support teachers engaging in these practices.

Economic-Analysis Program for a Communication System

NASA Technical Reports Server (NTRS)

Chamberlain, R. G.

1986-01-01

Prices and profits of alternative designs compared. Objective of Land Mobile Satellite Service Finance Report (LMSS) program is to provide means for comparing alternative designs of LMSS systems. Program is Multiplan worksheet program. Labels used in worksheet chosen for satellite-based cellular communication service, but analysis not restricted to such cases. LMSS written for interactive execution with Multiplan (version 1.2) and implemented on IBM PC series computer operating under DOS (version 2.11).

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…

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

Integrating enzyme fermentation in lignocellulosic ethanol production: life-cycle assessment and techno-economic analysis.

PubMed

Olofsson, Johanna; Barta, Zsolt; Börjesson, Pål; Wallberg, Ola

2017-01-01

Cellulase enzymes have been reported to contribute with a significant share of the total costs and greenhouse gas emissions of lignocellulosic ethanol production today. A potential future alternative to purchasing enzymes from an off-site manufacturer is to integrate enzyme and ethanol production, using microorganisms and part of the lignocellulosic material as feedstock for enzymes. This study modelled two such integrated process designs for ethanol from logging residues from spruce production, and compared it to an off-site case based on existing data regarding purchased enzymes. Greenhouse gas emissions and primary energy balances were studied in a life-cycle assessment, and cost performance in a techno-economic analysis. The base case scenario suggests that greenhouse gas emissions per MJ of ethanol could be significantly lower in the integrated cases than in the off-site case. However, the difference between the integrated and off-site cases is reduced with alternative assumptions regarding enzyme dosage and the environmental impact of the purchased enzymes. The comparison of primary energy balances did not show any significant difference between the cases. The minimum ethanol selling price, to reach break-even costs, was from 0.568 to 0.622 EUR L -1 for the integrated cases, as compared to 0.581 EUR L -1 for the off-site case. An integrated process design could reduce greenhouse gas emissions from lignocellulose-based ethanol production, and the cost of an integrated process could be comparable to purchasing enzymes produced off-site. This study focused on the environmental and economic assessment of an integrated process, and in order to strengthen the comparison to the off-site case, more detailed and updated data regarding industrial off-site enzyme production are especially important.

Operationally Comparable Effect Sizes for Quantifying Changes in Behavior, with Application to Meta-Analysis of Single-Case Studies

ERIC Educational Resources Information Center

Pustejovsky, James E.

2013-01-01

Single-case designs (SCDs) are a class of research methods for evaluating intervention effects by taking repeated measurements of an outcome over time on a single case, both before and after the deliberate introduction of a treatment. SCDs are used heavily in fields such as special education, school psychology, social work, and applied behavior…

Designing an autoverification system in Zagazig University Hospitals Laboratories: preliminary evaluation on thyroid function profile.

PubMed

Sediq, Amany Mohy-Eldin; Abdel-Azeez, Ahmad GabAllahm Hala

2014-01-01

The current practice in Zagazig University Hospitals Laboratories (ZUHL) is manual verification of all results for the later release of reports. These processes are time consuming and tedious, with large inter-individual variation that slows the turnaround time (TAT). Autoverification is the process of comparing patient results, generated from interfaced instruments, against laboratory-defined acceptance parameters. This study describes an autoverification engine designed and implemented in ZUHL, Egypt. A descriptive study conducted at ZUHL, from January 2012-December 2013. A rule-based system was used in designing an autoverification engine. The engine was preliminarily evaluated on a thyroid function panel. A total of 563 rules were written and tested on 563 simulated cases and 1673 archived cases. The engine decisions were compared to that of 4 independent expert reviewers. The impact of engine implementation on TAT was evaluated. Agreement was achieved among the 4 reviewers in 55.5% of cases, and with the engine in 51.5% of cases. The autoverification rate for archived cases was 63.8%. Reported lab TAT was reduced by 34.9%, and TAT segment from the completion of analysis to verification was reduced by 61.8%. The developed rule-based autoverification system has a verification rate comparable to that of the commercially available software. However, the in-house development of this system had saved the hospital the cost of commercially available ones. The implementation of the system shortened the TAT and minimized the number of samples that needed staff revision, which enabled laboratory staff to devote more time and effort to handle problematic test results and to improve patient care quality.

Glasses-type wearable computer displays: usability considerations examined with a 3D glasses case study.

PubMed

Chang, Joonho; Moon, Seung Ki; Jung, Kihyo; Kim, Wonmo; Parkinson, Matthew; Freivalds, Andris; Simpson, Timothy W; Baik, Seon Pill

2018-05-01

This study presents usability considerations and solutions for the design of glasses-type wearable computer displays and examines their effectiveness in a case study. Design countermeasures were investigated by a four-step design process: (1) preliminary design analysis; (2) design idea generation; (3) final design selection; and (4) virtual fitting trial. Three design interventions were devised from the design process: (1) weight balance to reduce pressure concentrated on the nose, (2) compliant temples to accommodate diverse head sizes and (3) a hanger mechanism to help spectacle users hang their wearable display on their eye glasses. To investigate their effectiveness, in the case study, the novel 3D glasses adopting the three interventions were compared with two existing 3D glasses in terms of neck muscle fatigue and subjective discomfort rating. While neck muscle fatigue was not significantly different among the three glasses (p = 0.467), the novel glasses had significantly smaller discomfort ratings (p = 0.009). Relevance to Industry: A four-step design process identified usability considerations and solutions for the design of glasses-type wearable computer displays. A novel 3D glasses was proposed through the process and its effectiveness was validated. The results identify design considerations and opportunities relevant to the emerging wearable display industry.

Using Disciplinary Literacies to Enhance Adolescents' Engineering Design Activity

ERIC Educational Resources Information Center

Wilson, Amy Alexandra; Smith, Emma; Householder, Daniel L.

2014-01-01

This comparative case study describes the literacy practices of two groups of adolescents as they sought to solve authentic problems through engineering design processes. Three types of data were collected as the groups addressed these problems: video- and audio-recordings of their conversations; adolescent-generated products; and pre- and…

Comparison of transhumeral socket designs utilizing patient assessment and in vivo skeletal and socket motion tracking: a case study.

PubMed

Resnik, Linda; Patel, Tarpit; Cooney, Shane G; Crisco, Joseph J; Fantini, Christopher

2016-01-01

This case study compares the impact of two prosthetic socket designs, a "traditional" transhumeral (TH) socket design and a Compression Released Stabilized (CRS) socket. A CRS socket was compared to the existing socket of two persons with transhumeral amputation. Comparisons included assessments of patient comfort and satisfaction with fit, as well as dynamic kinematic assessment using a novel high-speed, high-resolution, bi-plane video radiography system (XROMM, for X-ray Reconstruction of Moving Morphology). Subjects were more satisfied with the comfort of the traditional sockets, although they had positive impressions about aspects of the fit and style of the CRS socket, and thought that it provided better control. Dynamic kinematic assessment revealed that the CRS socket provided better control of the residual limb within the socket, and had less slippage as compared to a traditional TH socket design. The TH CRS socket provided better control of the residual limb within the socket, and had less slippage. However, participants were less satisfied with the comfort and overall utility of the CRS socket, and stated that additional fitting visits/modifications to the CRS socket were needed. It is possible that satisfaction with the CRS socket may have improved with prosthetic adjustment and more acclimation time. Implications for Rehabilitation A comfortable, good fitting prosthetic socket is the key factor in determining how long (or if) an upper limb amputee can tolerate wearing a prosthesis. This case series was a comparison of two socket designs, a 'traditional' socket design and a Compression Released Stabilized (CRS) socket design in persons with transhumeral amputation. The CRS socket provided better control of the residual limb within the socket, and had less slippage. However, its tightness made it more difficult to don. Both subjects were less satisfied with the comfort and overall utility of the CRS socket. However, satisfaction might have been improved with additional fitting visits and more acclimation time.

The common case study: Lockheed design of a supersonic cruise vehicle

NASA Technical Reports Server (NTRS)

Clauss, J. S., Jr.; Hays, A. P.; Wilson, J. R.

1978-01-01

The objective was to compare the characteristics of SSTs designed for the same mission by Lockheed, McDonnell Douglas, British Aerospace (U.K.), Aerospatiale (France), and the USSR. This comparison was to be used to calibrate parametric design studies of the tradeoff between SST direct operating cost (DOC) and noise levels at the FAR 36 certification points. The guidelines for this common case study were to design an aircraft with the following mission: payload 23 247 kg (51 250 lbm), range - 7000 km (3780 n. mi.), and cruise Mach number - 2.2. Field length was constrained to 3505 m (11 500 ft). Other airfield constraints and fuel reserves were also specified, but no noise constraints were applied.

A Circular Surgical Stapler Designed to Anastomose Aorta and Dacron Tube Graft

PubMed Central

2013-01-01

Background: A circular aortic stapler has been developed to anastomose the open end of the aorta to a size-matched Dacron tube graft in one quick motion and without having to pull sutures through the aortic wall. Methods: A prototype was developed, and its design and function were tested in bench experiments and compared with hand-sewn anastomosis. The basic design of the stapler is a central rod (anvil) surrounded by 10 stapling limbs, which can be closed over the anvil in a full circle, with staples extruded by turning a knob at the back. To test its function, a Dacron tube graft was inserted in the middle of a length of bovine aorta. One side was anastomosed with the stapler and the other hand-sewn in each of 10 experiments. Bovine blood was infused under increasing pressure. Results: It took considerably less time to complete the stapled anastomosis than the hand-sewn side (3 minutes, 46 seconds versus 15 minutes, 42 seconds). Initial leak occurred at low pressures on the hand-sewn side (mean pressure 40 mm Hg) compared with the stapled side (mean pressure 70 mm Hg). In 7 of 10 experiments, the leak became too brisk on the hand-sewn side to sustain pressure, compared with 3 of 10 with stapled anastomoses. The stapling device performed well in all cases except when the bovine aorta was too thick for the staples (two cases) or when there was a missed branch at the anastomotic site (one case). Conclusions: These experiments validate the concept and the design of this aortic stapler. There are some limitations in the current design, which will need to be modified before its use in live animals or clinically. PMID:26798678

A Circular Surgical Stapler Designed to Anastomose Aorta and Dacron Tube Graft: Validation of the Concept and Comparison to Hand-Sewn Anastomosis in Bench Experiments.

PubMed

Raza, Syed T

2013-06-01

A circular aortic stapler has been developed to anastomose the open end of the aorta to a size-matched Dacron tube graft in one quick motion and without having to pull sutures through the aortic wall. A prototype was developed, and its design and function were tested in bench experiments and compared with hand-sewn anastomosis. The basic design of the stapler is a central rod (anvil) surrounded by 10 stapling limbs, which can be closed over the anvil in a full circle, with staples extruded by turning a knob at the back. To test its function, a Dacron tube graft was inserted in the middle of a length of bovine aorta. One side was anastomosed with the stapler and the other hand-sewn in each of 10 experiments. Bovine blood was infused under increasing pressure. It took considerably less time to complete the stapled anastomosis than the hand-sewn side (3 minutes, 46 seconds versus 15 minutes, 42 seconds). Initial leak occurred at low pressures on the hand-sewn side (mean pressure 40 mm Hg) compared with the stapled side (mean pressure 70 mm Hg). In 7 of 10 experiments, the leak became too brisk on the hand-sewn side to sustain pressure, compared with 3 of 10 with stapled anastomoses. The stapling device performed well in all cases except when the bovine aorta was too thick for the staples (two cases) or when there was a missed branch at the anastomotic site (one case). These experiments validate the concept and the design of this aortic stapler. There are some limitations in the current design, which will need to be modified before its use in live animals or clinically.

Study design options in evaluating gene-environment interactions: practical considerations for a planned case-control study of pediatric leukemia.

PubMed

Goodman, Michael; Dana Flanders, W

2007-04-01

We compare methodological approaches for evaluating gene-environment interaction using a planned study of pediatric leukemia as a practical example. We considered three design options: a full case-control study (Option I), a case-only study (Option II), and a partial case-control study (Option III), in which information on controls is limited to environmental exposure only. For each design option we determined its ability to measure the main effects of environmental factor E and genetic factor G, and the interaction between E and G. Using the leukemia study example, we calculated sample sizes required to detect and odds ratio (OR) of 2.0 for E alone, an OR of 10 for G alone and an interaction G x E of 3. Option I allows measuring both main effects and interaction, but requires a total sample size of 1,500 cases and 1,500 controls. Option II allows measuring only interaction, but requires just 121 cases. Option III allows calculating the main effect of E, and interaction, but not the main effect of G, and requires a total of 156 cases and 133 controls. In this case, the partial case-control study (Option III) appears to be more efficient with respect to its ability to answer the research questions for the amount of resources required. The design options considered in this example are not limited to observational epidemiology and may be applicable in studies of pharmacogenomics, survivorship, and other areas of pediatric ALL research.

Methodology Series Module 2: Case-control Studies.

PubMed

Setia, Maninder Singh

2016-01-01

Case-Control study design is a type of observational study. In this design, participants are selected for the study based on their outcome status. Thus, some participants have the outcome of interest (referred to as cases), whereas others do not have the outcome of interest (referred to as controls). The investigator then assesses the exposure in both these groups. The investigator should define the cases as specifically as possible. Sometimes, definition of a disease may be based on multiple criteria; thus, all these points should be explicitly stated in case definition. An important aspect of selecting a control is that they should be from the same 'study base' as that of the cases. We can select controls from a variety of groups. Some of them are: General population; relatives or friends; and hospital patients. Matching is often used in case-control control studies to ensure that the cases and controls are similar in certain characteristics, and it is a useful technique to increase the efficiency of the study. Case-Control studies can usually be conducted relatively faster and are inexpensive - particularly when compared with cohort studies (prospective). It is useful to study rare outcomes and outcomes with long latent periods. This design is not very useful to study rare exposures. Furthermore, they may also be prone to certain biases - selection bias and recall bias.

Matched samples logistic regression in case-control studies with missing values: when to break the matches.

PubMed

Hansson, Lisbeth; Khamis, Harry J

2008-12-01

Simulated data sets are used to evaluate conditional and unconditional maximum likelihood estimation in an individual case-control design with continuous covariates when there are different rates of excluded cases and different levels of other design parameters. The effectiveness of the estimation procedures is measured by method bias, variance of the estimators, root mean square error (RMSE) for logistic regression and the percentage of explained variation. Conditional estimation leads to higher RMSE than unconditional estimation in the presence of missing observations, especially for 1:1 matching. The RMSE is higher for the smaller stratum size, especially for the 1:1 matching. The percentage of explained variation appears to be insensitive to missing data, but is generally higher for the conditional estimation than for the unconditional estimation. It is particularly good for the 1:2 matching design. For minimizing RMSE, a high matching ratio is recommended; in this case, conditional and unconditional logistic regression models yield comparable levels of effectiveness. For maximizing the percentage of explained variation, the 1:2 matching design with the conditional logistic regression model is recommended.

Design of the North Carolina Prostate Cancer Comparative Effectiveness and Survivorship Study (NC ProCESS).

PubMed

Chen, Ronald C; Carpenter, William R; Kim, Mimi; Hendrix, Laura H; Agans, Robert P; Meyer, Anne-Marie; Hoffmeyer, Anna; Reeve, Bryce B; Nielsen, Matthew E; Usinger, Deborah S; Strigo, Tara S; Jackman, Anne M; Anderson, Mary; Godley, Paul A

2015-01-01

The North Carolina Prostate Cancer Comparative Effectiveness & Survivorship Study (NC ProCESS) was designed in collaboration with stakeholders to compare the effectiveness of different treatment options for localized prostate cancer. Using the Rapid Case Ascertainment system of the North Carolina Central Cancer Registry, 1,419 patients (57% of eligible) with newly-diagnosed localized prostate cancer were enrolled from January 2011 to June 2013, on average 5 weeks after diagnosis. All participants were enrolled prior to treatment and this population-based cohort is sociodemographically diverse. Prospective follow-up continues to collect data on treatments received, disease control, survival and patient-reported outcomes. This study highlights several important considerations regarding stakeholder involvement, study design and generalizability regarding comparative effectiveness research in prostate cancer.

A Case Study of Knowledge Management in the "Back Office" of Two English Football Clubs

ERIC Educational Resources Information Center

Doloriert, Clair; Whitworth, Kieran

2011-01-01

Purpose: This study aims to explore knowledge management (KM) practice in the "back office" of two English football clubs. Design/methodology/approach: The paper takes the form of a comparative case study of two medium-sized businesses using multi-method data including unstructured interviews, structured questionnaires and document…

The Effects of Cognitive Conflict Management on Cognitive Development and Science Achievement

ERIC Educational Resources Information Center

Budiman, Zainol Badli; Halim, Lilia; Mohd Meerah, Subahan; Osman, Kamisah

2014-01-01

Three teaching methods were compared in this study, namely a Cognitive Conflict Management Module (CCM) that is infused into Cognitive Acceleration through Science Education (CASE), (Module A) CASE without CCM (Module B) and a conventional teaching method. This study employed a pre- and post-test quasi-experimental design using non-equivalent…

Magic from Social Networks that Talk to Management: Four Cases

ERIC Educational Resources Information Center

Sugarman, Barry

2010-01-01

Purpose: The purpose of this paper is to understand how social networks can help to produce the "magic" of extraordinary results for organizations. Design/methodology/approach: In this exploratory study four cases (from published reports) are compared in order to illustrate different management approaches to utilizing the power of networks.…

Comparative Case Study on Designing and Applying Flipped Classroom at Universities

ERIC Educational Resources Information Center

Lim, Cheolil; Kim, Sunyoung; Lee, Jihyun; Kim, Hyeonsu; Han, Hyeongjong

2014-01-01

There have been many reports on cases where flipped classroom was applied which put greater emphasis on conducting various learning activities during class. However, there is a limitation in redesigning existing university lectures as flipped classrooms merely based on reports that describe the learning activities of and their effects on…

Methods and Case Studies for Teaching and Learning about Failure and Safety.

ERIC Educational Resources Information Center

Bignell, Victor

1999-01-01

Discusses methods for analyzing case studies of failures of technological systems. Describes two distance learning courses that compare standard models of failure and success with the actuality of given scenarios. Provides teaching and learning materials and information sources for application to aspects of design, manufacture, inspection, use,…

47 CFR 73.3597 - Procedures on transfer and assignment applications.

Code of Federal Regulations, 2010 CFR

2010-10-01

... hearing in any case where the agreements, arrangements or understandings with the seller provide for the... current licensee or permittee for less than one year, the application will be designated for hearing on... through the Minority Ownership Policy or after a comparative hearing or, in the case of low power TV and...

Using generalized additive (mixed) models to analyze single case designs.

PubMed

Shadish, William R; Zuur, Alain F; Sullivan, Kristynn J

2014-04-01

This article shows how to apply generalized additive models and generalized additive mixed models to single-case design data. These models excel at detecting the functional form between two variables (often called trend), that is, whether trend exists, and if it does, what its shape is (e.g., linear and nonlinear). In many respects, however, these models are also an ideal vehicle for analyzing single-case designs because they can consider level, trend, variability, overlap, immediacy of effect, and phase consistency that single-case design researchers examine when interpreting a functional relation. We show how these models can be implemented in a wide variety of ways to test whether treatment is effective, whether cases differ from each other, whether treatment effects vary over cases, and whether trend varies over cases. We illustrate diagnostic statistics and graphs, and we discuss overdispersion of data in detail, with examples of quasibinomial models for overdispersed data, including how to compute dispersion and quasi-AIC fit indices in generalized additive models. We show how generalized additive mixed models can be used to estimate autoregressive models and random effects and discuss the limitations of the mixed models compared to generalized additive models. We provide extensive annotated syntax for doing all these analyses in the free computer program R. Copyright © 2013 Society for the Study of School Psychology. Published by Elsevier Ltd. All rights reserved.

Child Maltreatment as a Risk Factor for Opioid Dependence: Comparison of Family Characteristics and Type and Severity of Child Maltreatment with a Matched Control Group

ERIC Educational Resources Information Center

Conroy, Elizabeth; Degenhardt, Louisa; Mattick, Richard P.; Nelson, Elliot C.

2009-01-01

Objective: To examine the prevalence, characteristics and risk factors for child maltreatment among opioid-dependent persons compared to a community sample of similar social disadvantage. Method: The study employed a case-control design. Cases had a history of opioid pharmacotherapy. Controls were frequency matched to cases with regard to age, sex…

Comparing Dutch Case management care models for people with dementia and their caregivers: The design of the COMPAS study

PubMed Central

2012-01-01

Background Dementia care in the Netherlands is shifting from fragmented, ad hoc care to more coordinated and personalised care. Case management contributes to this shift. The linkage model and a combination of intensive case management and joint agency care models were selected based on their emerging prominence in the Netherlands. It is unclear if these different forms of case management are more effective than usual care in improving or preserving the functioning and well-being at the patient and caregiver level and at the societal cost. The objective of this article is to describe the design of a study comparing these two case management care models against usual care. Clinical and cost outcomes are investigated while care processes and the facilitators and barriers for implementation of these models are considered. Design Mixed methods include a prospective, observational, controlled, cohort study among persons with dementia and their primary informal caregiver in regions of the Netherlands with and without case management including a qualitative process evaluation. Inclusion criteria for the cohort study are: community-dwelling individuals with a dementia diagnosis who are not terminally-ill or anticipate admission to a nursing home within 6 months and with an informal caregiver who speaks fluent Dutch. Person with dementia-informal caregiver dyads are followed for two years. The primary outcome measure is the Neuropsychiatric Inventory for the people with dementia and the General Health Questionnaire for their caregivers. Secondary outcomes include: quality of life and needs assessment in both persons with dementia and caregivers, activity of daily living, competence of care, and number of crises. Costs are measured from a societal perspective using cost diaries. Process indicators measure the quality of care from the participant’s perspective. The qualitative study uses purposive sampling methods to ensure a wide variation of respondents. Semi-structured interviews with stakeholders based on the theoretical model of adaptive implementation are planned. Discussion This study provides relevant insights into care processes, description of two case management models along with clinical and economic data from persons with dementia and caregivers to clarify important differences in two case management care models compared to usual care. PMID:22640695

Towards high performing hospital enterprise systems: an empirical and literature based design framework

NASA Astrophysics Data System (ADS)

dos Santos Fradinho, Jorge Miguel

2014-05-01

Our understanding of enterprise systems (ES) is gradually evolving towards a sense of design which leverages multidisciplinary bodies of knowledge that may bolster hybrid research designs and together further the characterisation of ES operation and performance. This article aims to contribute towards ES design theory with its hospital enterprise systems design (HESD) framework, which reflects a rich multidisciplinary literature and two in-depth hospital empirical cases from the US and UK. In doing so it leverages systems thinking principles and traditionally disparate bodies of knowledge to bolster the theoretical evolution and foundation of ES. A total of seven core ES design elements are identified and characterised with 24 main categories and 53 subcategories. In addition, it builds on recent work which suggests that hospital enterprises are comprised of multiple internal ES configurations which may generate different levels of performance. Multiple sources of evidence were collected including electronic medical records, 54 recorded interviews, observation, and internal documents. Both in-depth cases compare and contrast higher and lower performing ES configurations. Following literal replication across in-depth cases, this article concludes that hospital performance can be improved through an enriched understanding of hospital ES design.

Flexible engineering designs for urban water management in Lusaka, Zambia.

PubMed

Tembo, Lucy; Pathirana, Assela; van der Steen, Peter; Zevenbergen, Chris

2015-01-01

Urban water systems are often designed using deterministic single values as design parameters. Subsequently the different design alternatives are compared using a discounted cash flow analysis that assumes that all parameters remain as-predicted for the entire project period. In reality the future is unknown and at best a possible range of values for design parameters can be estimated. A Monte Carlo simulation could then be used to calculate the expected Net Present Value of project alternatives, as well as so-called target curves (cumulative frequency distribution of possible Net Present Values). The same analysis could be done after flexibilities were incorporated in the design, either by using decision rules to decide about the moment of capacity increase, or by buying Real Options (in this case land) to cater for potential capacity increases in the future. This procedure was applied to a sanitation and wastewater treatment case in Lusaka, Zambia. It included various combinations of on-site anaerobic baffled reactors and off-site waste stabilisation ponds. For the case study, it was found that the expected net value of wastewater treatment systems can be increased by 35-60% by designing a small flexible system with Real Options, rather than a large inflexible system.

Towards a Taxonomy of Intergenerational Knowledge Transfer Practices: Insights from an International Comparison (Germany-Quebec)

ERIC Educational Resources Information Center

Kuyken, Kerstin; Ebrahimi, Mehran; Saives, Anne-Laure

2018-01-01

Purpose: This paper aims to develop a better understanding of intergenerational knowledge transfer (IKT) practices by adopting a context-related and comparative perspective. Design/methodology/approach: A qualitative case study design involving 83 interviews and non-participative observation in German and Quebec organizations has been chosen.…

Strategic Industrial Alliances in Paper Industry: XML- vs Ontology-Based Integration Platforms

ERIC Educational Resources Information Center

Naumenko, Anton; Nikitin, Sergiy; Terziyan, Vagan; Zharko, Andriy

2005-01-01

Purpose: To identify cases related to design of ICT platforms for industrial alliances, where the use of Ontology-driven architectures based on Semantic web standards is more advantageous than application of conventional modeling together with XML standards. Design/methodology/approach: A comparative analysis of the two latest and the most obvious…

A framework for sustainable nanomaterial selection and design based on performance, hazard, and economic considerations.

PubMed

Falinski, Mark M; Plata, Desiree L; Chopra, Shauhrat S; Theis, Thomas L; Gilbertson, Leanne M; Zimmerman, Julie B

2018-04-30

Engineered nanomaterials (ENMs) and ENM-enabled products have emerged as potentially high-performance replacements to conventional materials and chemicals. As such, there is an urgent need to incorporate environmental and human health objectives into ENM selection and design processes. Here, an adapted framework based on the Ashby material selection strategy is presented as an enhanced selection and design process, which includes functional performance as well as environmental and human health considerations. The utility of this framework is demonstrated through two case studies, the design and selection of antimicrobial substances and conductive polymers, including ENMs, ENM-enabled products and their alternatives. Further, these case studies consider both the comparative efficacy and impacts at two scales: (i) a broad scale, where chemical/material classes are readily compared for primary decision-making, and (ii) within a chemical/material class, where physicochemical properties are manipulated to tailor the desired performance and environmental impact profile. Development and implementation of this framework can inform decision-making for the implementation of ENMs to facilitate promising applications and prevent unintended consequences.

Authoritarianism as a Driver of U.S. Foreign Policy: The Cases of Myanmar, Vietnam, and North Korea

DTIC Science & Technology

2016-12-01

environments. E. RESEARCH DESIGN The methodology of this paper employs statistical analysis and comparative case studies. With proxy scales that...U.S. FOREIGN POLICY: THE CASES OF MYANMAR, VIETNAM, AND NORTH KOREA by Rang Lee December 2016 Thesis Co-Advisor: Tristan Mabry Thesis Co-Advisor...COVERED Master’s thesis 4. TITLE AND SUBTITLE AUTHORITARIANISM AS A DRIVER OF U.S. FOREIGN POLICY: THE CASES OF MYANMAR, VIETNAM, AND NORTH KOREA 5

Implementation and value of using a split-plot reader design in a study of digital breast tomosynthesis in a breast cancer assessment clinic

NASA Astrophysics Data System (ADS)

Mall, Suneeta; Brennan, Patrick C.; Mello-Thoms, Claudia

2015-03-01

The rapid evolution in medical imaging has led to an increased number of recurrent trials, primarily to ensure that the efficacy of new imaging techniques is known. The cost associated with time and resources in conducting such trials is usually high. The recruitment of participants, in a medium to large reader study, is often very challenging as the demanding number of cases discourages involvement with the trial. We aim to evaluate the efficacy of Digital Breast Tomosynthesis (DBT) in a recall assessment clinic in Australia in a prospective multi-reader-multi-case (MRMC) trial. Conducting such a study with the more commonly used fully crossed MRMC study design would require more cases and more cases read per reader, which was not viable in our setting. With an aim to perform a cost effective yet statistically efficient clinical trial, we evaluated alternative study designs, particularly the alternative split-plot MRMC study design and compared and contrasted it with more commonly used fully crossed MRMC study design. Our results suggest that `split-plot', an alternative MRMC study design, could be very beneficial for medium to large clinical trials and the cost associated with conducting such trials can be greatly reduced without adversely effecting the variance of the study. We have also noted an inverse dependency between number of required readers and cases to achieve a target variance. This suggests that split-plot could also be very beneficial for studies that focus on cases that are hard to procure or readers that are hard to recruit. We believe that our results may be relevant to other researchers seeking to design a medium to large clinical trials.

The effect of improving task representativeness on capturing nurses’ risk assessment judgements: a comparison of written case simulations and physical simulations

PubMed Central

2013-01-01

Background The validity of studies describing clinicians’ judgements based on their responses to paper cases is questionable, because - commonly used - paper case simulations only partly reflect real clinical environments. In this study we test whether paper case simulations evoke similar risk assessment judgements to the more realistic simulated patients used in high fidelity physical simulations. Methods 97 nurses (34 experienced nurses and 63 student nurses) made dichotomous assessments of risk of acute deterioration on the same 25 simulated scenarios in both paper case and physical simulation settings. Scenarios were generated from real patient cases. Measures of judgement ‘ecology’ were derived from the same case records. The relationship between nurses’ judgements, actual patient outcomes (i.e. ecological criteria), and patient characteristics were described using the methodology of judgement analysis. Logistic regression models were constructed to calculate Lens Model Equation parameters. Parameters were then compared between the modeled paper-case and physical-simulation judgements. Results Participants had significantly less achievement (ra) judging physical simulations than when judging paper cases. They used less modelable knowledge (G) with physical simulations than with paper cases, while retaining similar cognitive control and consistency on repeated patients. Respiration rate, the most important cue for predicting patient risk in the ecological model, was weighted most heavily by participants. Conclusions To the extent that accuracy in judgement analysis studies is a function of task representativeness, improving task representativeness via high fidelity physical simulations resulted in lower judgement performance in risk assessments amongst nurses when compared to paper case simulations. Lens Model statistics could prove useful when comparing different options for the design of simulations used in clinical judgement analysis. The approach outlined may be of value to those designing and evaluating clinical simulations as part of education and training strategies aimed at improving clinical judgement and reasoning. PMID:23718556

Fully integrated aerodynamic/dynamic optimization of helicopter rotor blades

NASA Technical Reports Server (NTRS)

Walsh, Joanne L.; Lamarsh, William J., II; Adelman, Howard M.

1992-01-01

This paper describes a fully integrated aerodynamic/dynamic optimization procedure for helicopter rotor blades. The procedure combines performance and dynamics analyses with a general purpose optimizer. The procedure minimizes a linear combination of power required (in hover, forward flight, and maneuver) and vibratory hub shear. The design variables include pretwist, taper initiation, taper ratio, root chord, blade stiffnesses, tuning masses, and tuning mass locations. Aerodynamic constraints consist of limits on power required in hover, forward flight and maneuver; airfoil section stall; drag divergence Mach number; minimum tip chord; and trim. Dynamic constraints are on frequencies, minimum autorotational inertia, and maximum blade weight. The procedure is demonstrated for two cases. In the first case the objective function involves power required (in hover, forward flight, and maneuver) and dynamics. The second case involves only hover power and dynamics. The designs from the integrated procedure are compared with designs from a sequential optimization approach in which the blade is first optimized for performance and then for dynamics. In both cases, the integrated approach is superior.

Fully integrated aerodynamic/dynamic optimization of helicopter rotor blades

NASA Technical Reports Server (NTRS)

Walsh, Joanne L.; Lamarsh, William J., II; Adelman, Howard M.

1992-01-01

A fully integrated aerodynamic/dynamic optimization procedure is described for helicopter rotor blades. The procedure combines performance and dynamic analyses with a general purpose optimizer. The procedure minimizes a linear combination of power required (in hover, forward flight, and maneuver) and vibratory hub shear. The design variables include pretwist, taper initiation, taper ratio, root chord, blade stiffnesses, tuning masses, and tuning mass locations. Aerodynamic constraints consist of limits on power required in hover, forward flight and maneuvers; airfoil section stall; drag divergence Mach number; minimum tip chord; and trim. Dynamic constraints are on frequencies, minimum autorotational inertia, and maximum blade weight. The procedure is demonstrated for two cases. In the first case, the objective function involves power required (in hover, forward flight and maneuver) and dynamics. The second case involves only hover power and dynamics. The designs from the integrated procedure are compared with designs from a sequential optimization approach in which the blade is first optimized for performance and then for dynamics. In both cases, the integrated approach is superior.

Comparing Youth Opinions toward Compulsory Voting across Five Countries

ERIC Educational Resources Information Center

Pesek, Jessamay T.

2014-01-01

This study uses a comparative case study design to examine youth (ages 13-20) opinions toward compulsory voting across five democratic countries: Colombia, Ecuador, Mexico, Peru, and the United States. Youth responses toward compulsory voting demonstrate how youth come to learn about citizen rights and responsibilities with varied understandings…

75 FR 54117 - Building Energy Standards Program: Preliminary Determination Regarding Energy Efficiency...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-03

... Response to Comments on Previous Analysis C. Summary of the Comparative Analysis 1. Quantitative Analysis 2... preliminary quantitative analysis are specific building designs, in most cases with specific spaces defined... preliminary determination. C. Summary of the Comparative Analysis DOE carried out both a broad quantitative...

Importance of relationship context in HIV transmission: results from a qualitative case-control study in Rakai, Uganda.

PubMed

Higgins, Jenny A; Mathur, Sanyukta; Eckel, Elizabeth; Kelley, Laura; Kelly, Laura; Nakyanjo, Neema; Sekamwa, Richard; Namatovu, Josephine; Ddaaki, William; Nakubulwa, Rosette; Namakula, Sylvia; Nalugoda, Fred; Santelli, John S

2014-04-01

We present results from life history interviews with 60 young adults from southern Uganda. Using a novel qualitative case-control design, we compared newly HIV-positive cases with HIV-negative controls matched on age, gender, marital status, and place of residence. Relationship context was the most salient theme differentiating cases from controls. Compared with HIV-negative respondents, recent seroconverters described relationships marked by poorer communication, greater suspicion and mistrust, and larger and more transitory sexual networks. Results highlight the importance of dyadic approaches to HIV and possibly of couple-based interventions. Using HIV-matched pairs allowed additional understanding of the factors influencing transmission. This hybrid methodological approach holds promise for future studies of sexual health.

Importance of Relationship Context in HIV Transmission: Results From a Qualitative Case-Control Study in Rakai, Uganda

PubMed Central

Mathur, Sanyukta; Eckel, Elizabeth; Kelly, Laura; Nakyanjo, Neema; Sekamwa, Richard; Namatovu, Josephine; Ddaaki, William; Nakubulwa, Rosette; Namakula, Sylvia; Nalugoda, Fred; Santelli, John S.

2014-01-01

We present results from life history interviews with 60 young adults from southern Uganda. Using a novel qualitative case-control design, we compared newly HIV-positive cases with HIV-negative controls matched on age, gender, marital status, and place of residence. Relationship context was the most salient theme differentiating cases from controls. Compared with HIV-negative respondents, recent seroconverters described relationships marked by poorer communication, greater suspicion and mistrust, and larger and more transitory sexual networks. Results highlight the importance of dyadic approaches to HIV and possibly of couple-based interventions. Using HIV-matched pairs allowed additional understanding of the factors influencing transmission. This hybrid methodological approach holds promise for future studies of sexual health. PMID:24524490

Human patient simulators and interactive case studies: a comparative analysis of learning outcomes and student perceptions.

PubMed

Howard, Valerie Michele; Ross, Carl; Mitchell, Ann M; Nelson, Glenn M

2010-01-01

Although human patient simulators provide an innovative teaching method for nursing students, they are quite expensive. To investigate the value of this expenditure, a quantitative, quasi-experimental, two-group pretest and posttest design was used to compare two educational interventions: human patient simulators and interactive case studies. The sample (N = 49) consisted of students from baccalaureate, accelerated baccalaureate, and diploma nursing programs. Custom-designed Health Education Systems, Inc examinations were used to measure knowledge before and after the implementation of the two educational interventions. Students in the human patient simulation group scored significantly higher than did those in the interactive case study group on the posttest Health Education Systems, Inc examination, and no significant difference was found in student scores among the three types of nursing programs that participated in the study. Data obtained from a questionnaire administered to participants indicated that students responded favorably to the use of human patient simulators as a teaching method.

JPL Thermal Design Modeling Philosophy and NASA-STD-7009 Standard for Models and Simulations - A Case Study

NASA Technical Reports Server (NTRS)

Avila, Arturo

2011-01-01

The Standard JPL thermal engineering practice prescribes worst-case methodologies for design. In this process, environmental and key uncertain thermal parameters (e.g., thermal blanket performance, interface conductance, optical properties) are stacked in a worst case fashion to yield the most hot- or cold-biased temperature. Thus, these simulations would represent the upper and lower bounds. This, effectively, represents JPL thermal design margin philosophy. Uncertainty in the margins and the absolute temperatures is usually estimated by sensitivity analyses and/or by comparing the worst-case results with "expected" results. Applicability of the analytical model for specific design purposes along with any temperature requirement violations are documented in peer and project design review material. In 2008, NASA released NASA-STD-7009, Standard for Models and Simulations. The scope of this standard covers the development and maintenance of models, the operation of simulations, the analysis of the results, training, recommended practices, the assessment of the Modeling and Simulation (M&S) credibility, and the reporting of the M&S results. The Mars Exploration Rover (MER) project thermal control system M&S activity was chosen as a case study determining whether JPL practice is in line with the standard and to identify areas of non-compliance. This paper summarizes the results and makes recommendations regarding the application of this standard to JPL thermal M&S practices.

A Comparative Study of GDSS (Group Decision Support System) Use: Empirical Evidence and Model Design

DTIC Science & Technology

1987-09-01

G D SS ............................................... 67 APPENDIX A: ENERGY INTERNATIONAL CASE ...................... 69 APPENDIX B: QUESTIONNAIRE...the impact of many of the disadvantages. C. DESIRABLE CHARACTERISTICS OF A GDSS The designer of a GDSS must consider the major functional requirements...592]. Alter has stated that interaction with the GDSS is not the most important aspect of the system. Instead, designers should direct their energies

A design study of hydrazine and biowaste resistojets

NASA Technical Reports Server (NTRS)

Page, R. J.; Stoner, W. A.; Barker, L.

1986-01-01

A generalized modeling program was adapted in BASIC on a personal computer to compare the performance of four types of biowaste resistojets and two types of hydrazine augmenters. Analyzed biowaste design types were: (1) an electrically conductive ceramic heater-exchanger of zirconia; (2) a truss heater of platinum in cross flow; (3) an immersed bicoiled tubular heater-exchanger; and (4) a nonexposed, refractory metal, radiant heater in a central cavity within a heat exchanger case. Concepts 2 and 3 are designed to have an efficient, stainless steel outer pressure case. The hydrazine design types are: (5) an immersed bicoil heater exchanger and (6) a nonexposed radiant heater now with a refractory metal case. The ceramic biowaste resistojet has the highest specific impulse growth potential at 2000 K of 192.5 (CO2) and 269 s (H2O). The bicoil produces the highest augmenter temperature of 1994 K for a 2073 K heater giving 317 s at .73 overall efficiency. Detailed temperature profiles of each of the designs are shown. The scaled layout drawings of each are presented with recommended materials and fabrication methods.

Fan Performance From Duct Rake Instrumentation on a 1.294 Pressure Ratio, 725 ft/sec Tip Speed Turbofan Simulator Using Vaned Passage Casing Treatment

NASA Technical Reports Server (NTRS)

Fite, E. Brian

2006-01-01

A 1.294 pressure ratio, 725 ft/sec tip speed, variable pitch low noise fan was designed and tested in the NASA Glenn 9- by 15-foot Wind Tunnel. The design included a casing treatment that used recirculation to extend the fan stall line and provide an acceptable operating range. Overall aerodynamic experimental results are presented for this low tip speed, low noise fan without casing treatment as well as using several variants of the casing treatment that moved the air extraction and insertion axial locations. Measurements were made to assess effects on performance, operability, and noise. An unusual instability was discovered near the design operating line and is documented in the fan operating range. Measurements were made to compare stall margin improvements as well as measure the performance impact of the casing treatments. Experimental results in the presence of simulated inlet distortion, via screens, are presented for the baseline and recirculation casing treatment configurations. Estimates are made for the quantity of recirculation weight flow based on limited instrumentation in the recirculation system along with discussion of results and conclusions

The Impact of Management Decision-Making on Student Success in Community Colleges: A Case Study

ERIC Educational Resources Information Center

Alt, Albert G.

2012-01-01

This case study examined a multi-college community college district in northern California in a primarily rural area, to understand how their practices compared to management best practices designed to improve student success, barriers that may exist in implementing best practices, and how the institution may improve its own practices. The problem…

A Case-Controlled Investigation of Tactile Reactivity in Young Children with and without Global Developmental Delay

ERIC Educational Resources Information Center

Barney, Chantel C.; Tervo, Raymond; Wilcox, George L.; Symons, Frank J.

2017-01-01

Assessing tactile function among children with intellectual, motor, and communication impairments remains a clinical challenge. A case control design was used to test whether children with global developmental delays (GDD; n = 20) would be more/less reactive to a modified quantitative sensory test (mQST) compared to controls (n = 20). Reactivity…

Case study comparison of two pellet heating facilities in southeastern Alaska

Treesearch

David Nicholls; Allen Brackley; Robert Deering; Daniel Parrent; Brian Kleinhenz; Craig. Moore

2016-01-01

Over the past decade, wood-energy use in Alaska has grown dramatically. Since 2000, several dozen new wood-energy installations have been established, with numerous others in the design or construction phase. This case study report compares two wood-pellet heating systems in Juneau, Alaska. The Tlingit-Haida Regional Housing Authority, a native housing authority that...

Effect Size in Single-Case Research: A Review of Nine Nonoverlap Techniques

ERIC Educational Resources Information Center

Parker, Richard I.; Vannest, Kimberly J.; Davis, John L.

2011-01-01

With rapid advances in the analysis of data from single-case research designs, the various behavior-change indices, that is, effect sizes, can be confusing. To reduce this confusion, nine effect-size indices are described and compared. Each of these indices examines data nonoverlap between phases. Similarities and differences, both conceptual and…

User-composable Electronic Health Record Improves Efficiency of Clinician Data Viewing for Patient Case Appraisal: A Mixed-Methods Study

PubMed Central

Senathirajah, Yalini; Kaufman, David; Bakken, Suzanne

2016-01-01

Background: Challenges in the design of electronic health records (EHRs) include designing usable systems that must meet the complex, rapidly changing, and high-stakes information needs of clinicians. The ability to move and assemble elements together on the same page has significant human-computer interaction (HCI) and efficiency advantages, and can mitigate the problems of negotiating multiple fixed screens and the associated cognitive burdens. Objective: We compare MedWISE—a novel EHR that supports user-composable displays—with a conventional EHR in terms of the number of repeat views of data elements for patient case appraisal. Design and Methods: The study used mixed-methods for examination of clinical data viewing in four patient cases. The study compared use of an experimental user-composable EHR with use of a conventional EHR, for case appraisal. Eleven clinicians used a user-composable EHR in a case appraisal task in the laboratory setting. This was compared with log file analysis of the same patient cases in the conventional EHR. We investigated the number of repeat views of the same clinical information during a session and across these two contexts, and compared them using Fisher’s exact test. Results: There was a significant difference (p<.0001) in proportion of cases with repeat data element viewing between the user-composable EHR (14.6 percent) and conventional EHR (72.6 percent). Discussion and Conclusion: Users of conventional EHRs repeatedly viewed the same information elements in the same session, as revealed by log files. Our findings are consistent with the hypothesis that conventional systems require that the user view many screens and remember information between screens, causing the user to forget information and to have to access the information a second time. Other mechanisms (such as reduction in navigation over a population of users due to interface sharing, and information selection) may also contribute to increased efficiency in the experimental system. Systems that allow a composable approach that enables the user to gather together on the same screen any desired information elements may confer cognitive support benefits that can increase productive use of systems by reducing fragmented information. By reducing cognitive overload, it can also enhance the user experience. PMID:27195306

BactoGeNIE: A large-scale comparative genome visualization for big displays

DOE PAGES

Aurisano, Jillian; Reda, Khairi; Johnson, Andrew; ...

2015-08-13

The volume of complete bacterial genome sequence data available to comparative genomics researchers is rapidly increasing. However, visualizations in comparative genomics--which aim to enable analysis tasks across collections of genomes--suffer from visual scalability issues. While large, multi-tiled and high-resolution displays have the potential to address scalability issues, new approaches are needed to take advantage of such environments, in order to enable the effective visual analysis of large genomics datasets. In this paper, we present Bacterial Gene Neighborhood Investigation Environment, or BactoGeNIE, a novel and visually scalable design for comparative gene neighborhood analysis on large display environments. We evaluate BactoGeNIE throughmore » a case study on close to 700 draft Escherichia coli genomes, and present lessons learned from our design process. In conclusion, BactoGeNIE accommodates comparative tasks over substantially larger collections of neighborhoods than existing tools and explicitly addresses visual scalability. Given current trends in data generation, scalable designs of this type may inform visualization design for large-scale comparative research problems in genomics.« less

BactoGeNIE: a large-scale comparative genome visualization for big displays

PubMed Central

2015-01-01

Background The volume of complete bacterial genome sequence data available to comparative genomics researchers is rapidly increasing. However, visualizations in comparative genomics--which aim to enable analysis tasks across collections of genomes--suffer from visual scalability issues. While large, multi-tiled and high-resolution displays have the potential to address scalability issues, new approaches are needed to take advantage of such environments, in order to enable the effective visual analysis of large genomics datasets. Results In this paper, we present Bacterial Gene Neighborhood Investigation Environment, or BactoGeNIE, a novel and visually scalable design for comparative gene neighborhood analysis on large display environments. We evaluate BactoGeNIE through a case study on close to 700 draft Escherichia coli genomes, and present lessons learned from our design process. Conclusions BactoGeNIE accommodates comparative tasks over substantially larger collections of neighborhoods than existing tools and explicitly addresses visual scalability. Given current trends in data generation, scalable designs of this type may inform visualization design for large-scale comparative research problems in genomics. PMID:26329021

BactoGeNIE: A large-scale comparative genome visualization for big displays

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

Aurisano, Jillian; Reda, Khairi; Johnson, Andrew

The volume of complete bacterial genome sequence data available to comparative genomics researchers is rapidly increasing. However, visualizations in comparative genomics--which aim to enable analysis tasks across collections of genomes--suffer from visual scalability issues. While large, multi-tiled and high-resolution displays have the potential to address scalability issues, new approaches are needed to take advantage of such environments, in order to enable the effective visual analysis of large genomics datasets. In this paper, we present Bacterial Gene Neighborhood Investigation Environment, or BactoGeNIE, a novel and visually scalable design for comparative gene neighborhood analysis on large display environments. We evaluate BactoGeNIE throughmore » a case study on close to 700 draft Escherichia coli genomes, and present lessons learned from our design process. In conclusion, BactoGeNIE accommodates comparative tasks over substantially larger collections of neighborhoods than existing tools and explicitly addresses visual scalability. Given current trends in data generation, scalable designs of this type may inform visualization design for large-scale comparative research problems in genomics.« less

Risk of Narcolepsy after AS03 Adjuvanted Pandemic A/H1N1 2009 Influenza Vaccine in Adults: A Case-Coverage Study in England.

PubMed

Stowe, Julia; Andrews, Nicholas; Kosky, Christopher; Dennis, Gary; Eriksson, Sofia; Hall, Andrew; Leschziner, Guy; Reading, Paul; Shneerson, John M; Donegan, Katherine; Miller, Elizabeth

2016-05-01

An increased risk of narcolepsy has been observed in children following ASO3-adjuvanted pandemic A/H1N1 2009 (Pandemrix) vaccine. We investigated whether this risk extends to adults in England. Six adult sleep centers in England were visited between November 2012 and February 2014 and vaccination/clinical histories obtained from general practitioners. Suspected narcolepsy cases aged older than 17 y were selected. The risk of narcolepsy following Pandemrix was calculated using cases diagnosed by the time of the center visits and those with a diagnosis by November 30, 2011 after which there was increased awareness of the risk in children. The odds of vaccination in cases and in matched population data were compared using a case-coverage design. Of 1,446 possible cases identified, most had onset before 2009 or were clearly not narcolepsy. Of the 60 remaining cases, 20 were excluded after expert review, leaving 40 cases with narcolepsy; 5 had received Pandemrix between 3 and 18 mo before onset. All the vaccinated cases had cataplexy, two received a diagnosis by November 2011 and two were aged 40 y or older. The odds ratio for vaccination in cases compared to the population was 4.24 (95% confidence interval 1.45-12.38) using all cases and 9.06 (1.90-43.17) using cases with a diagnosis by November 2011, giving an attributable risk of 0.59 cases per 100,000 doses. We found a significantly increased risk of narcolepsy in adults following Pandemrix vaccination in England. The risk was lower than that seen in children using a similar study design. © 2016 Associated Professional Sleep Societies, LLC.

Design considerations for case series models with exposure onset measurement error.

PubMed

Mohammed, Sandra M; Dalrymple, Lorien S; Sentürk, Damla; Nguyen, Danh V

2013-02-28

The case series model allows for estimation of the relative incidence of events, such as cardiovascular events, within a pre-specified time window after an exposure, such as an infection. The method requires only cases (individuals with events) and controls for all fixed/time-invariant confounders. The measurement error case series model extends the original case series model to handle imperfect data, where the timing of an infection (exposure) is not known precisely. In this work, we propose a method for power/sample size determination for the measurement error case series model. Extensive simulation studies are used to assess the accuracy of the proposed sample size formulas. We also examine the magnitude of the relative loss of power due to exposure onset measurement error, compared with the ideal situation where the time of exposure is measured precisely. To facilitate the design of case series studies, we provide publicly available web-based tools for determining power/sample size for both the measurement error case series model as well as the standard case series model. Copyright © 2012 John Wiley & Sons, Ltd.

Methodology Series Module 2: Case-control Studies

PubMed Central

Setia, Maninder Singh

2016-01-01

Case-Control study design is a type of observational study. In this design, participants are selected for the study based on their outcome status. Thus, some participants have the outcome of interest (referred to as cases), whereas others do not have the outcome of interest (referred to as controls). The investigator then assesses the exposure in both these groups. The investigator should define the cases as specifically as possible. Sometimes, definition of a disease may be based on multiple criteria; thus, all these points should be explicitly stated in case definition. An important aspect of selecting a control is that they should be from the same ‘study base’ as that of the cases. We can select controls from a variety of groups. Some of them are: General population; relatives or friends; and hospital patients. Matching is often used in case-control control studies to ensure that the cases and controls are similar in certain characteristics, and it is a useful technique to increase the efficiency of the study. Case-Control studies can usually be conducted relatively faster and are inexpensive – particularly when compared with cohort studies (prospective). It is useful to study rare outcomes and outcomes with long latent periods. This design is not very useful to study rare exposures. Furthermore, they may also be prone to certain biases – selection bias and recall bias. PMID:27057012

Efficient logistic regression designs under an imperfect population identifier.

PubMed

Albert, Paul S; Liu, Aiyi; Nansel, Tonja

2014-03-01

Motivated by actual study designs, this article considers efficient logistic regression designs where the population is identified with a binary test that is subject to diagnostic error. We consider the case where the imperfect test is obtained on all participants, while the gold standard test is measured on a small chosen subsample. Under maximum-likelihood estimation, we evaluate the optimal design in terms of sample selection as well as verification. We show that there may be substantial efficiency gains by choosing a small percentage of individuals who test negative on the imperfect test for inclusion in the sample (e.g., verifying 90% test-positive cases). We also show that a two-stage design may be a good practical alternative to a fixed design in some situations. Under optimal and nearly optimal designs, we compare maximum-likelihood and semi-parametric efficient estimators under correct and misspecified models with simulations. The methodology is illustrated with an analysis from a diabetes behavioral intervention trial. © 2013, The International Biometric Society.

Research on Race and Ethnic Relations in the Army

DTIC Science & Technology

1975-06-01

one - group pretest - posttest design24 ). In another case, it...training--and then compare the two groups both on their pretest and on their posttest scores (a nonequivalent control group design25). Thus the possible...whether there are aspects of Army life to which majority- and minority- group soldiers respond differently. One project sought to gather

Use of Continuous Exponential Families to Link Forms via Anchor Tests. Research Report. ETS RR-11-11

ERIC Educational Resources Information Center

Haberman, Shelby J.; Yan, Duanli

2011-01-01

Continuous exponential families are applied to linking test forms via an internal anchor. This application combines work on continuous exponential families for single-group designs and work on continuous exponential families for equivalent-group designs. Results are compared to those for kernel and equipercentile equating in the case of chained…

How to study the aetiology of burn injury: the epidemiological approach.

PubMed

Bouter, L M; Knipschild, P G; van Rijn, J L; Meertens, R M

1989-06-01

Effective prevention of burn injury should be based on sound aetiological knowledge. This article deals with epidemiological methods to study the incidence of burn injury as a function of its risk factors. Central methodological issues are comparability of baseline prognosis, comparability of measurements (of effects in cohort studies and of risk factors in case-control studies), and comparability of external circumstances. These principles are clarified with a number of fictitious examples of risk factors for burn injury. It is explained that in preventive trials comparability may be achieved by randomization, blinding and placebo intervention. The main tools in non-experimental studies are deliberate selection and multivariate analysis. Special attention is given to the definition of the source population and to reducing measurement incomparability in case-control studies. Some well-designed case-control studies following these principles might bring effective prevention of burn injury some steps nearer.

A SIX-WEEK SUPERVISED EXERCISE AND EDUCATIONAL INTERVENTION AFTER TOTAL HIP ARTHROPLASTY: A CASE SERIES

PubMed Central

Madara, Kathleen; Zeni, Joseph A

2017-01-01

Background and Purpose Most rehabilitation interventions after total hip arthroplasty (THA) are not designed to return patients to high-levels of physical activity and, thus, low levels of physical activity and residual weakness are common. The purpose of this case series was to describe the feasibility and preliminary efficacy of an exercise and education intervention for patients after THA who have already completed formal outpatient physical therapy. Study Design Case series Case Description Two participants underwent unilateral THA seven (case A) or eight (case B) months prior to the intervention. Individuals participated in 18 treatment sessions that included progressive aerobic and strengthening exercises and meetings with a health coach. Change in function, strength, and self-reported physical activity were measured. Outcomes 12 months after surgery were compared to a historical cohort of patients after THA. Outcome There were no adverse events during the intervention. At the end of the intervention, hip and knee strength on the surgical side increased approximately 30% compared to baseline in both cases. Activity level, and recreational performance, including walking up stairs and hiking uphill (case A), and running and golfing (case B), improved by the end of the intervention. Most changes were maintained at follow-up, although hip strength for case B decreased 27% after discharge from the intervention. Outcomes for both cases exceeded historical averages for patients 12 months after THA, with the exception of strength in case B. Discussion The exercise intervention was well tolerated and without negative effects in two participants. Both participants increased their ability to complete demanding recreational and sports-related activities, physical activity, and demonstrated improved hip abductor and knee extensor strength. Further research is needed to evaluate the implementation and effectiveness of similar interventions after THA. Level of Evidence Level 4 PMID:28515981

Optimal case-control matching in practice.

PubMed

Cologne, J B; Shibata, Y

1995-05-01

We illustrate modern matching techniques and discuss practical issues in defining the closeness of matching for retrospective case-control designs (in which the pool of subjects already exists when the study commences). We empirically compare matching on a balancing score, analogous to the propensity score for treated/control matching, with matching on a weighted distance measure. Although both methods in principle produce balance between cases and controls in the marginal distributions of the matching covariates, the weighted distance measure provides better balance in practice because the balancing score can be poorly estimated. We emphasize the use of optimal matching based on efficient network algorithms. An illustration is based on the design of a case-control study of hepatitis B virus infection as a possible confounder and/or effect modifier of radiation-related primary liver cancer in atomic bomb survivors.

Design optimization of a vaneless ``fish-friendly'' swirl injector for small water turbines

NASA Astrophysics Data System (ADS)

Airody, Ajith; Peterson, Sean D.

2015-11-01

Small-scale hydro-electric plants are attractive options for powering remote sites, as they draw energy from local bodies of water. However, the environmental impact on the aquatic life drawn into the water turbine is a concern. To mitigate adverse consequences on the local fauna, small-scale water turbine design efforts have focused on developing ``fish-friendly'' facilities. The components of these turbines tend to have wider passages between the blades when compared to traditional turbines, and the rotors are designed to spin at much lower angular velocities, thus allowing fish to pass through safely. Galt Green Energy has proposed a vaneless casing that provides the swirl component to the flow approaching the rotor, eliminating the need for inlet guide vanes. We numerically model the flow through the casing using ANSYS CFX to assess the evolution of the axial and circumferential velocity symmetry and uniformity in various cross-sections within and downstream of the injector. The velocity distributions, as well as the pressure loss through the injector, are functions of the pitch angle and number of revolutions of the casing. Optimization of the casing design is discussed via an objective function consisting of the velocity and pressure performance measures.

Factors Affecting the Designation of Cerebrovascular Diseases as Work-Related in Administrative Litigation

PubMed Central

Kim, Hyeongsu; Rim, Hwayoung; Chang, Sounghoon; Lee, Kunsei

2008-01-01

The purpose of this study was to identify factors that could be used as standardized criteria for evaluating occupational diseases in initial assessments or requests for examination. Using 100 administrative litigation cases on the work-relatedness of cerebrovascular diseases (CVDs) by the Seoul Branch of the Korea Labor Welfare Corporation (KLWC) from 1997 to 2002, we estimated the relationship between the investigated variables and designation of the work-relatedness of the CVD. As for the age, the odds ratio of the acceptance rate of a case as work-related in subjects over 60 yr of age was 0.08 (95% CI, 0.01-0.75), which was compared to subjects under 30 yr of age. Regarding working hours, the odds ratio of the acceptance rate of a case as work-related in CVDs in those over 56 hr was 9.50 (95% CI, 1.92-47.10) when compared to those less than 56 hr. As for the benefit type, the odds ratio of the acceptance rate of a case as work-related in medical benefits was 5.74 (95% CI, 1.29-25.54), compared to survivor benefits. As for the criteria for defining situations as work overload, the odds ratio of the acceptance rate of a case as work-related in injured workers was 12.06 (95% CI, 3.12-46.62), compared to that in non-injured workers. Our findings show that the criteria for defining situations of work overload played an important role in assessing the work-relatedness of CVDs in administrative litigation, and it is necessary to make the scientific evidence on judgement of work-relatedness on overwork. PMID:18437006

Does high flexion after total knee replacement really improve our patients' quality of life at a short-term follow-up? : a comparative case-control study with hyperflex PFC Sigma versus a Triathlon knee series.

PubMed

Mencière, Maxime L; Epinette, Jean-Alain; Gabrion, Antoine; Arnalsteen, Damien; Mertl, Patrice

2014-10-01

A full range of motion after total knee arthroplasty has become more and more requested by our patients, leading to novel designs of knee implants, the so-called "hyperflex" knees. The aim of the present study was to confirm whether or not hyperflexion of operated knees really improves the patients' quality of life. A retrospective comparative case-control study has been carried out to compare clinical results shown in two types of knee prosthesis, from two homogeneous paired groups of patients including 45 cases of a "hyperflex" model (RP-F), while the control group consisted of 43 cases of a "regular design" model (Triathlon) in terms of expected postoperative flexion. The hyperflex group demonstrated significant higher mean values of passive flexion at 119.9° in the RP-F group versus 111.1° in the Triathlon group. However, global results in the "regular" control group were significantly better than the "hyperflex" study group, in both IKS knee and functional scores at 84.4 points (RP-F) vs. 89.8 points (Triathlon), and 84.6 points (RP-F) vs. 89.5 points (Triathlon), respectively. Moreover, the self-administered KOOS questionnaire was significantly in favor of the control group, with 73.5 points in RP-F knees versus 86.0 points for Triathlon knees at global KOOS postoperative scores. The quality of life of operated patients after TKA obviously would be considered as the main priority, which was better obtained by a "regular design" in our study. Hence "high flexion" cannot be considered as an absolute target when choosing a model for total knee arthroplasty.

Comparing U.S. Army suicide cases to a control sample: initial data and methodological lessons.

PubMed

Alexander, Cynthia L; Reger, Mark A; Smolenski, Derek J; Fullerton, Nicole R

2014-10-01

Identification of risk and protective factors for suicide is a priority for the United States military, especially in light of the recent steady increase in military suicide rates. The Department of Defense Suicide Event Report contains comprehensive data on suicides for active duty military personnel, but no analogous control data is available to permit identification of factors that differentially determine suicide risk. This proof-of-concept study was conducted to determine the feasibility of collecting such control data. The study employed a prospective case-control design in which control cases were randomly selected from a large Army installation at a rate of four control participants for every qualifying Army suicide. Although 111 Army suicides were confirmed during the study period, just 27 control soldiers completed the study. Despite the small control sample, preliminary analyses comparing suicide cases to controls identified several factors more frequently reported for suicide cases, including recent failed intimate relationships, outpatient mental health history, mood disorder diagnosis, substance abuse history, and prior self-injury. No deployment-related risk factors were found. These data are consistent with existing literature and form a foundation for larger control studies. Methodological lessons learned regarding study design and recruitment are discussed to inform future studies. Reprint & Copyright © 2014 Association of Military Surgeons of the U.S.

Comparing Acquisition Strategies: Open Architecture versus Product Lines

DTIC Science & Technology

2010-04-30

software • New SOW language for accepting software deliveries – Enables third-party reuse • Additional SOW language regarding conducting software code walkthroughs and for using integrated development environments ...change the business environment must be the primary factor that drives the technical approach. Accordingly, there are business case decisions to be...elements of a system design should be made available to the customer to observe throughout the design process. Electronic access to the design environment

Comparative Analysis of RF Emission Based Fingerprinting Techniques for ZigBee Device Classification

DTIC Science & Technology

quantify the differences invarious RF fingerprinting techniques via comparative analysis of MDA/ML classification results. The findings herein demonstrate...correct classification rates followed by COR-DNA and then RF-DNA in most test cases and especially in low Eb/N0 ranges, where ZigBee is designed to operate.

Counterpoint Piece: The Case for Variety in Corrective Feedback Research

ERIC Educational Resources Information Center

Lyster, Roy; Ranta, Leila

2013-01-01

Goo and Mackey (this issue) outline several apparent design flaws in studies that have compared the impact of different types of corrective feedback (CF). Furthermore, they argue that SLA researchers should stop comparing recasts to other types of CF because they are inherently different kinds of phenomena. Our response to their article addresses…

Teaching Children with Language-Learning Disabilities to Plan and Revise Compare-Contrast Texts

ERIC Educational Resources Information Center

Shen, Mei; Troia, Gary A.

2018-01-01

This study used a multiple-probe, multiple-baseline single-case design to investigate the efficacy of planning, and then revising strategy instruction using self-regulated strategy development on the compare-contrast writing performance of three late elementary students with language-learning disabilities. After receiving the planning instruction,…

Design aspects of zeppelin operations from case histories

NASA Technical Reports Server (NTRS)

Maiersperger, W. P.

1975-01-01

Some widely held beliefs concerning the practicability of rigid airships in air carrier operations are discussed. It is shown by a review of past operational experience, and some basic aerostatic theory, their actual record and the reasons for their demise. Problems of atmospheric density and temperature variations, meteorological factors, aerodynamic stability and control, and mooring difficulties are discussed and related to actual case histories. Structural and flight efficiencies are compared to airplane efficiencies for airplanes contemporary with the zeppelin as well as modern designs. The difficulty of supporting new, commercial airship developments on an economic basis is made clear.

Effects of Buckling Knockdown Factor, Internal Pressure and Material on the Design of Stiffened Cylinders

NASA Technical Reports Server (NTRS)

Lovejoy, Andrew E.; Hilburger, Mark W.; Chunchu, Prasad B.

2010-01-01

A design study was conducted to investigate the effect shell buckling knockdown factor (SBKF), internal pressure and aluminum alloy material selection on the structural weight of stiffened cylindrical shells. Two structural optimization codes were used for the design study to determine the optimum minimum-weight design for a series of design cases, and included an in-house developed genetic algorithm (GA) code and PANDA2. Each design case specified a unique set of geometry, material, knockdown factor combinations and loads. The resulting designs were examined and compared to determine the effects of SBKF, internal pressure and material selection on the acreage design weight and controlling failure mode. This design study shows that use of less conservative SBKF values, including internal pressure, and proper selection of material alloy can result in significant weight savings for stiffened cylinders. In particular, buckling-critical cylinders with integrally machined stiffener construction can benefit from the use of thicker plate material that enables taller stiffeners, even when the stiffness, strength and density properties of these materials appear to be inferior.

Holding Abusers Accountable: An Elder Abuse Forensic Center Increases Criminal Prosecution of Financial Exploitation

ERIC Educational Resources Information Center

Navarro, Adria E.; Gassoumis, Zachary D.; Wilber, Kathleen H.

2013-01-01

Purpose: Despite growing awareness of elder abuse, cases are rarely prosecuted. The aim of this study was to examine the effectiveness of an elder abuse forensic center compared with usual care to increase prosecution of elder financial abuse. Design and Methods: Using one-to-one propensity score matching, cases referred to the Los Angeles County…

A Comparison of Case Study and Traditional Teaching Methods for Improvement of Oral Communication and Critical-Thinking Skills

ERIC Educational Resources Information Center

Noblitt, Lynnette; Vance, Diane E.; Smith, Michelle L. DePoy

2010-01-01

This study compares a traditional paper presentation approach and a case study method for the development and improvement of oral communication skills and critical-thinking skills in a class of junior forensic science majors. A rubric for rating performance in these skills was designed on the basis of the oral communication competencies developed…

A Multiple Case Study: The Effect of Professional Development on Teachers' Perceived Ability to Foster Resilience

ERIC Educational Resources Information Center

Klinger, Mary A.

2012-01-01

The purpose of this mixed methods study was to determine the effect of professional development on teachers' perceptions of their ability to foster resilience. Secondary questions investigated the effects of school level and socioeconomic status. An exploratory multi-site case study was designed to compare the perceptions of educators from…

Cell-Phone Use and Cancer: A Case Study Exploring the Scientific Method

ERIC Educational Resources Information Center

Colon Parrilla, Wilma V.

2007-01-01

Designed for an introductory nonmajors biology course, this case study presents students with a series of short news stories describing a scientific study of cell-phone use and its health effects. Students read the news stories and then the scientific paper they are based on, comparing the information presented by the news media to the information…

Monte Carlo simulation for light propagation in 3D tooth model

NASA Astrophysics Data System (ADS)

Fu, Yongji; Jacques, Steven L.

2011-03-01

Monte Carlo (MC) simulation was implemented in a three dimensional tooth model to simulate the light propagation in the tooth for antibiotic photodynamic therapy and other laser therapy. The goal of this research is to estimate the light energy deposition in the target region of tooth with given light source information, tooth optical properties and tooth structure. Two use cases were presented to demonstrate the practical application of this model. One case was comparing the isotropic point source and narrow beam dosage distribution and the other case was comparing different incident points for the same light source. This model will help the doctor for PDT design in the tooth.

Solar energy for process heat: Design/cost studies of four industrial retrofit applications

NASA Technical Reports Server (NTRS)

French, R. L.; Bartera, R. E.

1978-01-01

Five specific California plants with potentially attractive solar applications were identified in a process heat survey. These five plants were visited, process requirements evaluated, and conceptual solar system designs were generated. Four DOE (ERDA) sponsored solar energy system demonstration projects were also reviewed and compared to the design/cost cases included in this report. In four of the five cases investigated, retrofit installations providing significant amounts of thermal energy were found to be feasible. The fifth was rejected because of the condition of the building involved, but the process (soap making) appears to be an attractive potential solar application. Costs, however, tend to be high. Several potential areas for cost reduction were identified including larger collector modules and higher duty cycles.

Disease-Concordant Twins Empower Genetic Association Studies.

PubMed

Tan, Qihua; Li, Weilong; Vandin, Fabio

2017-01-01

Genome-wide association studies with moderate sample sizes are underpowered, especially when testing SNP alleles with low allele counts, a situation that may lead to high frequency of false-positive results and lack of replication in independent studies. Related individuals, such as twin pairs concordant for a disease, should confer increased power in genetic association analysis because of their genetic relatedness. We conducted a computer simulation study to explore the power advantage of the disease-concordant twin design, which uses singletons from disease-concordant twin pairs as cases and ordinary healthy samples as controls. We examined the power gain of the twin-based design for various scenarios (i.e., cases from monozygotic and dizygotic twin pairs concordant for a disease) and compared the power with the ordinary case-control design with cases collected from the unrelated patient population. Simulation was done by assigning various allele frequencies and allelic relative risks for different mode of genetic inheritance. In general, for achieving a power estimate of 80%, the sample sizes needed for dizygotic and monozygotic twin cases were one half and one fourth of the sample size of an ordinary case-control design, with variations depending on genetic mode. Importantly, the enriched power for dizygotic twins also applies to disease-concordant sibling pairs, which largely extends the application of the concordant twin design. Overall, our simulation revealed a high value of disease-concordant twins in genetic association studies and encourages the use of genetically related individuals for highly efficiently identifying both common and rare genetic variants underlying human complex diseases without increasing laboratory cost. © 2016 John Wiley & Sons Ltd/University College London.

Stiffness Parameter Design of Suspension Element of Under-Chassis-Equipment for A Rail Vehicle

NASA Astrophysics Data System (ADS)

Ma, Menglin; Wang, Chengqiang; Deng, Hai

2017-06-01

According to the frequency configuration requirements of the vibration of railway under-chassis-equipment, the three- dimension stiffness of the suspension elements of under-chassis-equipment is designed based on the static principle and dynamics principle. The design results of the concrete engineering case show that, compared with the design method based on the static principle, the three- dimension stiffness of the suspension elements designed by the dynamic principle design method is more uniform. The frequency and decoupling degree analysis show that the calculation frequency of under-chassis-equipment under the two design methods is basically the same as the predetermined frequency. Compared with the design method based on the static principle, the design method based on the dynamic principle is adopted. The decoupling degree can be kept high, and the coupling vibration of the corresponding vibration mode can be reduced effectively, which can effectively reduce the fatigue damage of the key parts of the hanging element.

Prediction of Gut Wall Integrity Loss in Viral Gastroenteritis by Non-Invasive Marker

PubMed Central

Elnady, Hala G.; Sherif, Lobna S.; Saleh, Maysa T.; El-Alameey, Inas R.; Youssef, Mai M.; El Shafie, Amal I.; Helwa, Iman; Raouf, Haiam Abdel; EL-Taweel, Ahmed N.

2015-01-01

BACKGROUND: Intestinal fatty acid binding proteins (I-FABPs) are mainly expressed in the intestinal villi, which are the initial site of destruction in viral gastroenteritis. AIM: This study was designed to assess serum I-FABPs as a predictor of gut wall integrity loss in viral gastroenteritis. PATIENTS AND METHODS: This case-control cross-sectional study was conducted on 93 cases of acute viral gastroenteritis. Twenty-eight healthy children matching in age were recruited as control group. Serum I-FABPs were measured using ELISA technique. Viral detection and typing were done by PCR for adenovirus, and by Reverse transcriptase PCR for rotavirus, astrovirus and norovirus. RESULTS: Serum I-FABPs level was significantly higher in the cases compared to the controls and was also higher in the 46 rotavirus gastroenteritis cases compared to other viral gastroenteritis cases. Serum I- FABPs level was significantly higher in severely dehydrated cases as compared to mildly dehydrated ones (P=0.037). CONCLUSION: Serum I-FABPs could be used as an early and sensitive predictor marker of gut wall integrity loss in children with viral gastroenteritis and its level can indicate case severity. PMID:27275194

Evaluating participatory decision processes: which methods inform reflective practice?

PubMed

Kaufman, Sanda; Ozawa, Connie P; Shmueli, Deborah F

2014-02-01

Evaluating participatory decision processes serves two key purposes: validating the usefulness of specific interventions for stakeholders, interveners and funders of conflict management processes, and improving practice. However, evaluation design remains challenging, partly because when attempting to serve both purposes we may end up serving neither well. In fact, the better we respond to one, the less we may satisfy the other. Evaluations tend to focus on endogenous factors (e.g., stakeholder selection, BATNAs, mutually beneficial tradeoffs, quality of the intervention, etc.), because we believe that the success of participatory decision processes hinges on them, and they also seem to lend themselves to caeteris paribus statistical comparisons across cases. We argue that context matters too and that contextual differences among specific cases are meaningful enough to undermine conclusions derived solely from comparisons of process-endogenous factors implicitly rooted in the caeteris paribus assumption. We illustrate this argument with an environmental mediation case. We compare data collected about it through surveys geared toward comparability across cases to information elicited through in-depth interviews geared toward case specifics. The surveys, designed by the U.S. Institute of Environmental Conflict Resolution, feed a database of environmental conflicts that can help make the (statistical) case for intervention in environmental conflict management. Our interviews elicit case details - including context - that enable interveners to link context specifics and intervention actions to outcomes. We argue that neither approach can "serve both masters." Copyright © 2013 Elsevier Ltd. All rights reserved.

Cancer and Blood Concentrations of the Co-mutagen Harmane in Essential Tremor

PubMed Central

Louis, Elan D.; Pellegrino, Kathryn M.; Factor-Litvak, Pam; Rios, Eileen; Jiang, Wendy; Henchcliffe, Claire; Zheng, Wei

2008-01-01

Background Blood concentrations of harmane, a tremor-producing neurotoxin, are elevated in essential tremor (ET). Harmane is also a co-mutagen. Objective To compare the prevalence of cancer in ET cases vs. controls, and determine whether blood harmane concentrations are elevated among ET cases with cancer. Methods Case-control design. Results 66/267 (24.7%) ET cases vs. 55/331 (16.6%) controls had cancer (adjusted OR 1.52, 95% CI 1.01 – 2.30, p = 0.04). Among specific cancer types, colon cancer was more prevalent in ET cases than controls (2.6% vs. 0.6%, p = 0.04). Log blood harmane concentration was higher in ET cases vs. controls (p = 0.02) and in participants with vs. without cancer (p = 0.02). Log blood harmane concentration was highest in ET cases with cancer when compared with other groups (p = 0.009). Discussion These links between cancer and ET and between high blood harmane and cancer in ET deserve further study. PMID:18709680

Cancer and blood concentrations of the comutagen harmane in essential tremor.

PubMed

Louis, Elan D; Pellegrino, Kathryn M; Factor-Litvak, Pam; Rios, Eileen; Jiang, Wendy; Henchcliffe, Claire; Zheng, Wei

2008-09-15

Blood concentrations of harmane, a tremor-producing neurotoxin, are elevated in essential tremor (ET). Harmane is also a comutagen. Using a case-control design, we compared the prevalence of cancer in ET cases vs. controls, and determined whether blood harmane concentrations are elevated among ET cases with cancer. 66/267 (24.7%) ET cases vs. 55/331 (16.6%) controls had cancer (adjusted OR 1.52, 95% CI 1.01-2.30, P = 0.04). Among specific cancer types, colon cancer was more prevalent in ET cases than controls (2.6% vs. 0.6%, P = 0.04). Log blood harmane concentration was higher in ET cases vs. controls (P = 0.02) and in participants with vs. without cancer (P = 0.02). Log blood harmane concentration was highest in ET cases with cancer when compared with other groups (P = 0.009). These links between cancer and ET and between high blood harmane and cancer in ET deserve further study. (c) 2007 Movement Disorder Society.

Correction Capability in the 3 Anatomic Planes of Different Pedicle Screw Designs in Scoliosis Instrumentation.

PubMed

Wang, Xiaoyu; Aubin, Carl-Eric; Coleman, John; Rawlinson, Jeremy

2017-05-01

Computer simulations to compare the correction capabilities of different pedicle screws in adolescent idiopathic scoliosis (AIS) instrumentations. To compare the correction and resulting bone-screw forces associated with different pedicle screws in scoliosis instrumentations. Pedicle screw fixation is widely used in surgical instrumentation for spinal deformity treatment. Screw design, correction philosophies, and surgical techniques are constantly evolving to achieve better control of the vertebrae and correction of the spinal deformity. Yet, there remains a lack of biomechanical studies that quantify the effects and advantages of different screw designs in terms of correction kinematics. The correction capabilities of fixed-angle, multiaxial, uniaxial, and saddle axial screws were kinematically analyzed, simulated, and compared. These simulations were based on the screw patterns and correction techniques proposed by 2 experienced surgeons for 2 AIS cases. Additional instrumentations were assessed to compare the correction and resulting bone-screw forces associated with each type of screw. The fixed-angle, uniaxial and saddle axial screws had similar kinematic behavior and performed better than multiaxial screws in the coronal and transverse planes (8% and 30% greater simulated corrections, respectively). Uniaxial and multiaxial screws were less effective than fixed-angle and saddle axial screws in transmitting compression/distraction to the anterior spine because of their sagittal plane mobility between the screw head and shank. Only the saddle axial screws allow vertebra angle in the sagittal plane to be independently adjusted. Pedicle screws of different designs performed differently for deformity corrections or for compensating screw placement variations in different anatomic planes. For a given AIS case, screw types should be determined based on the particular instrumentation objectives, the deformity's stiffness and characteristics so as to make the best of the screw designs.

Using National Surveys To Improve the Efficiency and Effectiveness of Broad-Based Program Evaluations.

ERIC Educational Resources Information Center

Clark, Sheldon B.; Boser, Judith A.

The suggestions offered in this paper are based on the experiences of two scientific researchers of how evaluations undertaken in a competitive arena, in which true experimental designs are not viable, can be designed in such a way that meaningful comparative data can be examined. Case studies of the Science and Engineering Research Semester and…

Designing from Cinema: Film as Trigger of the Creative Process in Architecture

ERIC Educational Resources Information Center

Bergera, Iñaki

2018-01-01

The present paper examines, in a case study format, the use of films, short films and audiovisual documentaries as reasoning and references for design assignments during the first years of an architectural degree course. The aim of this fruitful and comparable experience is not so much to study and verify the well-known synergies between film and…

A European Identity: Too Much to Hope For

DTIC Science & Technology

2015-12-01

Submitted in partial fulfillment of the requirements for the degree of MASTER OF ARTS IN SECURITY STUDIES (EUROPE AND EURASIA) from...RESEARCH DESIGN The research design for this thesis is a comparative case study between the UKIP and the AfD that focuses on the successes of...peak mostly during soccer matches and when interstate debts become problematic to repay. 76 David

The Cost-Effectiveness of Integrating HIV Counseling and Testing into Primary Health Care in the Ukraine.

PubMed

Johns, Benjamin; Doroshenko, Olena; Tarantino, Lisa; Cowley, Peter

2017-03-01

We estimate the number of HIV cases diagnosed, costs, and cost per HIV case detected associated with integrating HIV counseling and testing (HCT) into primary health care facilities in Ukraine. The study uses a difference-in-difference design with four districts implementing the intervention compared to 20 districts where HCT were offered only at specialized HIV clinics. There was a 2.01 (95 % CI: 1.12-3.61) times increase in the number of HIV cases detected per capita in intervention districts compared to other districts. The incremental cost of the intervention was $21,017 and the incremental cost per HIV case detected was $369. The average cost per HIV case detected before the intervention was $558. Engaging primary health care facilities to provide HCT is likely desirable from an efficiency point-of-view. However, the affordability of the intervention needs to be assessed because expansion will require additional investment.

Electromagnetic Design of a Radiofrequency Cavity

NASA Astrophysics Data System (ADS)

Montoya Soto, G. R.; Duarte Galvan, Carlos; Monzon, Ildefonso Leon; Podesta Lerma, Pedro Luis manuel; Valerio-Lizarraga, C. A.

2017-10-01

Electromagnetic and mechanical studies have been performed with the aim of build a RF cavity in the S-Band (2998 MHz), the design takes into consideration the relativistic change in the electron velocity through the acceleration cavity. Four cavity cases were considered at different input energies, 50 KeV, 100 KeV, 150 KeV, with output energies of 350 KeV, the designs show good acceleration efficiency and beam coherence comparable to the one created in the cathode.

Use of case-time-control design in pharmacovigilance applications: exploration with high-risk medications and unplanned hospital admissions in the Western Australian elderly.

PubMed

Price, Sylvie D; Holman, C D'Arcy J; Sanfilippo, Frank M; Emery, Jon D

2013-11-01

To use a case-time-control design to derive preliminary estimates of unplanned hospitalisations attributable to suspected high-risk medications in elderly Western Australians. Using pharmaceutical claims linked to inpatient and other health records, the study applied a case-time-control design and conditional logistic regression to estimate odds ratios (ORs) for unplanned hospital admissions associated with anticoagulants, antirheumatics, opioids, corticosteroids and four major groups of cardiovascular drugs. Attributable fractions (AFs) were derived from the ORs to estimate the number and proportion of admissions associated with drug exposure. Results were compared with those obtained from a more conventional method using International Classification of Diseases (ICD) external cause codes to identify admissions related to adverse drug events. The study involved 1 899 699 index hospital admissions. Six of the eight drug groups were associated with an increased risk of unplanned hospitalisation, opioids (adjusted OR = 1.81, 95%CI 1.75-1.88; AF = 44.9%) and corticosteroids (1.48, 1.42-1.54; 32.2%) linked with the highest risks. For all six, the estimated number of hospitalisations attributed to the medication in the exposed was higher (two to 31-fold) when derived from the case-time-control design compared with identification from ICD codes. This study provides an alternative approach for identifying potentially harmful medications and suggests that the use of ICD external causes may underestimate adverse drug events. It takes drug exposure into account, can be applied to individual medications and may overcome under-reporting issues associated with conventional methods. The approach shows great potential as part of a post-marketing pharmacovigilance monitoring system in Australia and elsewhere. Copyright © 2013 John Wiley & Sons, Ltd.

Co-Prime Frequency and Aperture Design for HF Surveillance, Wideband Radar Imaging, and Nonstationary Array Processing

DTIC Science & Technology

2018-03-10

can be generated using only two sensors in the physical array. In case ofredundancy in the difference coarray, there is more than one antenna pair that...estimation results based on the MUSIC algorithm using multi- frequency co-prime arrays. Both proportional and nonproportional source spectra cases are...be made in this case as well. However, two differences can be noticed by comparing the RMSE plots in Figs. 11 and 13. First, the RMSE takes on lower

"It's Harder Than We Thought It Would Be": A Comparative Case Study of Expert-Novice Experimentation Strategies.

ERIC Educational Resources Information Center

Hmelo-Silver, Cindy E.; Nagarajan, Anandi; Day, Roger S.

2002-01-01

Compares a group of expert cancer researchers with four groups of fourth year medical students (the "novice" groups) engaged in the task of designing a clinical trial to test a new cancer drug using a computer-based modeling tool, the Oncology Thinking Cap. (Contains 24 references.) (Author/YDS)

Factors Contributing to a School's Decision to Apply for the California Instructional School Garden Program

ERIC Educational Resources Information Center

Hazzard, Eric L.; Moreno, Elizabeth; Beall, Deborah L.; Zidenberg-Cherr, Sheri

2012-01-01

Objective: To compare the applicant schools (AS) to non-applicant schools (NAS) residing in the same school districts for the California Instructional School Garden Program and identify barriers to the application process. Methods: A case-control, cross-sectional study design was used to compare resources and school environments. Pearson…

The incident user design in comparative effectiveness research.

PubMed

Johnson, Eric S; Bartman, Barbara A; Briesacher, Becky A; Fleming, Neil S; Gerhard, Tobias; Kornegay, Cynthia J; Nourjah, Parivash; Sauer, Brian; Schumock, Glen T; Sedrakyan, Art; Stürmer, Til; West, Suzanne L; Schneeweiss, Sebastian

2013-01-01

Comparative effectiveness research includes cohort studies and registries of interventions. When investigators design such studies, how important is it to follow patients from the day they initiated treatment with the study interventions? Our article considers this question and related issues to start a dialogue on the value of the incident user design in comparative effectiveness research. By incident user design, we mean a study that sets the cohort's inception date according to patients' new use of an intervention. In contrast, most epidemiologic studies enroll patients who were currently or recently using an intervention when follow-up began. We take the incident user design as a reasonable default strategy because it reduces biases that can impact non-randomized studies, especially when investigators use healthcare databases. We review case studies where investigators have explored the consequences of designing a cohort study by restricting to incident users, but most of the discussion has been informed by expert opinion, not by systematic evidence. Published 2012. This article is a U.S. Government work and is in the public domain in the USA.

[The choice of the type of design in the clinical investigation studies. Case and control studies].

PubMed

Posada de la Paz, M

2004-09-01

Case-control studies are appropriate designs in neurology sciences to search for risk factors that have already occurred in a group of patients. In them, the subjects are selected on the basis of whether they have the disease or not and then they are compared in regards to the risk factor or prognosis investigated. These sorts of designs can be performed in a shorter and cheaper way than the regular cohort studies. They are appropriate for the evaluation of rare diseases and can examine multiple etiological factors for a single disease. On the contrary, they are not so efficient when rare exposures are involved. Incidence rates in exposed and non-exposed subjects cannot be calculated and on some occasions, the timing between exposure and outcome can be very difficult to establish. The Odds Ratio and its confident intervals is the measurement used for estimating the risk strength in this design. The clinical neurologist should be familiar with these terms, given the frequency of case-control studies described in neurology science literature, and should know their principal advantages and limitations.

Profile design for wings and propellers

NASA Technical Reports Server (NTRS)

Quast, A.; Horstmann, K. H.

1984-01-01

It has now become customary to develop profiles for wings and propellers for a given employment of the aircraft. This is possible because methods and computers are available to study an entire series of variants in comparatively short time. The basic viewpoints for profile design are presented. It is shown that laminarization has its advantages in almost all cases, including the design of a turbine blade and the design of the profile of an airliner. The requirements which profiles have to satisfy are discussed along with the possibilities for increasing lift on profiles.

Numerical verification of two-component dental implant in the context of fatigue life for various load cases.

PubMed

Szajek, Krzysztof; Wierszycki, Marcin

2016-01-01

Dental implant designing is a complex process which considers many limitations both biological and mechanical in nature. In earlier studies, a complete procedure for improvement of two-component dental implant was proposed. However, the optimization tasks carried out required assumption on representative load case, which raised doubts on optimality for the other load cases. This paper deals with verification of the optimal design in context of fatigue life and its main goal is to answer the question if the assumed load scenario (solely horizontal occlusal load) leads to the design which is also "safe" for oblique occlussal loads regardless the angle from an implant axis. The verification is carried out with series of finite element analyses for wide spectrum of physiologically justified loads. The design of experiment methodology with full factorial technique is utilized. All computations are done in Abaqus suite. The maximal Mises stress and normalized effective stress amplitude for various load cases are discussed and compared with the assumed "safe" limit (equivalent of fatigue life for 5e6 cycles). The obtained results proof that coronial-appical load component should be taken into consideration in the two component dental implant when fatigue life is optimized. However, its influence in the analyzed case is small and does not change the fact that the fatigue life improvement is observed for all components within whole range of analyzed loads.

Forums for Dialogue between University and Industry: A Case of Kenyatta University, Kenya and University of Padua, Italy

ERIC Educational Resources Information Center

Nyerere, Jackline; Friso, Valeria

2013-01-01

Purpose: This paper aims to analyse comparatively the existing partnerships between the University of Padua and the enterprises in Veneto region, Italy, on one hand and Kenyatta University and industries in Kenya on the other. Design/methodology/approach: This was a case study of the University of Padua in Veneto Region, Italy, and Kenyatta…

Epidemiological characteristics of reported sporadic and outbreak cases of E. coli O157 in people from Alberta, Canada (2000-2002): methodological challenges of comparing clustered to unclustered data.

PubMed

Pearl, D L; Louie, M; Chui, L; Doré, K; Grimsrud, K M; Martin, S W; Michel, P; Svenson, L W; McEwen, S A

2008-04-01

Using multivariable models, we compared whether there were significant differences between reported outbreak and sporadic cases in terms of their sex, age, and mode and site of disease transmission. We also determined the potential role of administrative, temporal, and spatial factors within these models. We compared a variety of approaches to account for clustering of cases in outbreaks including weighted logistic regression, random effects models, general estimating equations, robust variance estimates, and the random selection of one case from each outbreak. Age and mode of transmission were the only epidemiologically and statistically significant covariates in our final models using the above approaches. Weighing observations in a logistic regression model by the inverse of their outbreak size appeared to be a relatively robust and valid means for modelling these data. Some analytical techniques, designed to account for clustering, had difficulty converging or producing realistic measures of association.

Application of cetylpyridinium chloride and sodium chloride decontamination method for recovery of Mycobacterium tuberculosis from clinically suspected cases of pulmonary tuberculosis.

PubMed

Shinu, Pottathil; Singh, Varsha; Nair, Anroop; Mehrishi, Priya; Mehta, Sonia; Joshi, Ekta

2013-10-01

The study was designed to compare the efficacy of cetylpyridinium chloride (CPC) and sodium chloride (NaCl) decontamination method with N-acetyl L-Cystine (NALC) and sodium hydroxide (NaOH) decontamination (the reference method) method for the recovery of Mycobacterium tuberculosis (MTB) from clinically suspected cases of pulmonary tuberculosis. To evaluate CPC-NaCl and NALC-NaOH decontamination methods, sputum specimens (n = 796) were studied (culturing on Löwenstein-Jensen medium), and the performances were compared. The CPC-NaCl decontamination method demonstrated a sensitivity, specificity, negative predictive value, and positive predictive value of 97.99%, 87.53%, 70.19%, and 99.32%, respectively, when compared to NALC-NaOH decontamination method. In summary, CPC-NaCl decontamination method effectively detected significantly higher number of MTB cases (n = 208) than NALC-NaOH decontamination method (n = 149) particularly in sputum with scanty bacilli and smear-negative cases, indicating the potential of CPC-NaCl decontamination method to preserve paucibacillary cases more efficient than NALC-NaOH decontamination method. © 2013.

Open-cell vs. Closed-cell Stent Design Differences in Blood Flow Velocities after Carotid Stenting

PubMed Central

Pierce, Damon S.; Rosero, Eric B; Modrall, J Gregory; Adams-Huet, Beverley; Valentine, R James; Clagett, G Patrick; Timaran, Carlos H

2009-01-01

Objective The differential effect of stent design, i.e. open-cell vs. closed-cell configuration, on carotid velocities detected by duplex ultrasonography (DUS) has not been established. To identify possible stent design differences in carotid velocities, we analyzed our experience with DUS obtained before and immediately after CAS. Methods In a series of 141 CAS procedures performed over a 3 year period, data from the first postinterventional DUS and carotid angiograms were evaluated for each patient. Peak systolic velocities (PSV), end-diastolic velocities (EDV), and internal carotid artery-to-common carotid artery (ICA-CCA) PSV ratios were compared according to stent design. Differences in carotid velocities were analyzed using nonparametric statistical tests. Results Completion angiogram revealed successful revascularization and less that 30% residual stenosis in each case. The 30-day stroke-death rate in this series was 1.6% and was unrelated to stent type. Postintervention DUS was obtained a median of 5 days after CAS (interquartile range [IQR], 1–25 days). Closed-cell stents were used in 41 cases (29%) and open-cell stents in 100 cases (71%). The median PSV was significantly higher for closed-cell stents (122cm/s; IQR, 89–143cm/s) than for open-cell stents (95.9cm/s; IQR, 77.–123) (P=.007). Median EDV (36 vs. 29 cm/s; P=.006) and median ICA-CCA PSV ratio (1.6 vs. 1.1; P=.017) were also significantly higher for closed-cell stents. 45% of closed-cell stents had carotid velocities that exceeded the threshold of 50% stenosis by DUS criteria for a nonstented artery compared to 26% of open-cell stents (P=.04). In fact, closed cell-stents had a 2.2-fold increased risk of yielding abnormally elevated carotid velocities after CAS compared with open-cell stents (odds ratio, 2.2; 95% confidence interval, 1.02–4.9). Conclusions Carotid velocities are disproportionately elevated after CAS with closed-cell stents compared with open-cell stents, which suggests that velocity criteria for quantifying stenosis may require modification according to stent design. The importance of these differences in carotid velocities related to stent design and the potential relationship with recurrent stenosis remains to be established. PMID:19268763

26 CFR 1.482-8 - Examples of the best method rule.

Code of Federal Regulations, 2011 CFR

2011-04-01

... illustrate the comparative analysis required to apply this rule. As with all of the examples in these... case. Example 10. Cost of services plus method preferred to other methods. (i) FP designs and...

26 CFR 1.482-8 - Examples of the best method rule.

Code of Federal Regulations, 2013 CFR

2013-04-01

... illustrate the comparative analysis required to apply this rule. As with all of the examples in these... case. Example 10. Cost of services plus method preferred to other methods. (i) FP designs and...

26 CFR 1.482-8 - Examples of the best method rule.

Code of Federal Regulations, 2012 CFR

2012-04-01

... illustrate the comparative analysis required to apply this rule. As with all of the examples in these... case. Example 10. Cost of services plus method preferred to other methods. (i) FP designs and...

26 CFR 1.482-8 - Examples of the best method rule.

Code of Federal Regulations, 2010 CFR

2010-04-01

... illustrate the comparative analysis required to apply this rule. As with all of the examples in these... case. Example 10. Cost of services plus method preferred to other methods. (i) FP designs and...

Playing It Safe: Part I.

ERIC Educational Resources Information Center

Penman, Kenneth A.; Niccolai, Frances R.

1985-01-01

The first of a series of articles explains the legal principles of tort liability, waiver of liability, comparative negligence, assumption of risk, and contributory negligence. Summarizes the kinds of cases going to court involving sport facility design and operation. (MLF)

A novel scalable manufacturing process for the production of hydrogel-forming microneedle arrays.

PubMed

Lutton, Rebecca E M; Larrañeta, Eneko; Kearney, Mary-Carmel; Boyd, Peter; Woolfson, A David; Donnelly, Ryan F

2015-10-15

A novel manufacturing process for fabricating microneedle arrays (MN) has been designed and evaluated. The prototype is able to successfully produce 14×14 MN arrays and is easily capable of scale-up, enabling the transition from laboratory to industry and subsequent commercialisation. The method requires the custom design of metal MN master templates to produce silicone MN moulds using an injection moulding process. The MN arrays produced using this novel method was compared with centrifugation, the traditional method of producing aqueous hydrogel-forming MN arrays. The results proved that there was negligible difference between either methods, with each producing MN arrays with comparable quality. Both types of MN arrays can be successfully inserted in a skin simulant. In both cases the insertion depth was approximately 60% of the needle length and the height reduction after insertion was in both cases approximately 3%. Copyright © 2015 Elsevier B.V. All rights reserved.

Do Affordable Housing Projects Harm Suburban Communities? Crime, Property Values, and Taxes in Mount Laurel, NJ.

PubMed

Albright, Len; Derickson, Elizabeth S; Massey, Douglas S

2013-06-01

This paper offers a mixed-method analysis of the municipal-level consequences of an affordable housing development built in suburban New Jersey. Opponents of affordable housing development often suggest that creating affordable housing will harm surrounding communities. Feared consequences include increases in crime, declining property values, and rising taxes. To evaluate these claims, the paper uses the case of Mt. Laurel, NJ - the site of a landmark affordable housing legal case and subsequent affordable housing development. Employing a multiple time series group control design, we compare crime rates, property values, and property taxes in Mt. Laurel to outcomes in similar nearby municipalities that do not contain comparable affordable housing developments. We find that the opening of the affordable housing development was not associated with trends in crime, property values, or taxes, and discuss management practices and design features that may have mitigated potential negative externalities.

A novel scalable manufacturing process for the production of hydrogel-forming microneedle arrays

PubMed Central

Lutton, Rebecca E.M.; Larrañeta, Eneko; Kearney, Mary-Carmel; Boyd, Peter; Woolfson, A.David; Donnelly, Ryan F.

2015-01-01

A novel manufacturing process for fabricating microneedle arrays (MN) has been designed and evaluated. The prototype is able to successfully produce 14 × 14 MN arrays and is easily capable of scale-up, enabling the transition from laboratory to industry and subsequent commercialisation. The method requires the custom design of metal MN master templates to produce silicone MN moulds using an injection moulding process. The MN arrays produced using this novel method was compared with centrifugation, the traditional method of producing aqueous hydrogel-forming MN arrays. The results proved that there was negligible difference between either methods, with each producing MN arrays with comparable quality. Both types of MN arrays can be successfully inserted in a skin simulant. In both cases the insertion depth was approximately 60% of the needle length and the height reduction after insertion was in both cases approximately 3%. PMID:26302858

Do Affordable Housing Projects Harm Suburban Communities? Crime, Property Values, and Taxes in Mount Laurel, NJ

PubMed Central

Albright, Len; Derickson, Elizabeth S.; Massey, Douglas S.

2016-01-01

This paper offers a mixed-method analysis of the municipal-level consequences of an affordable housing development built in suburban New Jersey. Opponents of affordable housing development often suggest that creating affordable housing will harm surrounding communities. Feared consequences include increases in crime, declining property values, and rising taxes. To evaluate these claims, the paper uses the case of Mt. Laurel, NJ – the site of a landmark affordable housing legal case and subsequent affordable housing development. Employing a multiple time series group control design, we compare crime rates, property values, and property taxes in Mt. Laurel to outcomes in similar nearby municipalities that do not contain comparable affordable housing developments. We find that the opening of the affordable housing development was not associated with trends in crime, property values, or taxes, and discuss management practices and design features that may have mitigated potential negative externalities. PMID:27390552

Meta-Analysis of Single-Case Research Design Studies on Instructional Pacing.

PubMed

Tincani, Matt; De Mers, Marilyn

2016-11-01

More than four decades of research on instructional pacing has yielded varying and, in some cases, conflicting findings. The purpose of this meta-analysis was to synthesize single-case research design (SCRD) studies on instructional pacing to determine the relative benefits of brisker or slower pacing. Participants were children and youth with and without disabilities in educational settings, excluding higher education. Tau-U, a non-parametric statistic for analyzing data in SCRD studies, was used to determine effect size estimates. The article extraction yielded 13 instructional pacing studies meeting contemporary standards for high quality SCRD research. Eleven of the 13 studies reported small to large magnitude effects when two or more pacing parameters were compared, suggesting that instructional pacing is a robust instructional variable. Brisker instructional pacing with brief inter-trial interval (ITI) produced small increases in correct responding and medium to large reductions in challenging behavior compared with extended ITI. Slower instructional pacing with extended wait-time produced small increases in correct responding, but also produced small increases in challenging behavior compared with brief wait-time. Neither brief ITI nor extended wait-time meets recently established thresholds for evidence-based practice, highlighting the need for further instructional pacing research. © The Author(s) 2016.

Estimating the influenza vaccine effectiveness in elderly on a yearly basis using the Spanish influenza surveillance network--pilot case-control studies using different control groups, 2008-2009 season, Spain.

PubMed

Savulescu, Camelia; Valenciano, Marta; de Mateo, Salvador; Larrauri, Amparo

2010-04-01

We conducted a case-control and screening method studies to estimate influenza vaccine effectiveness (IVE) in the age group >or=65 years, based on the Spanish Influenza Sentinel Surveillance System (SISSS). Cases (influenza laboratory-confirmed) were compared to influenza-negative ILI patients (test-negative) and patients without ILI since the beginning of the season (non-ILI). For the screening method, cases' vaccination coverage was compared to the vaccination coverage of the GPs' catchment population. The results suggested a protective effect of the vaccine against laboratory-confirmed influenza in elderly in 2008-2009. The screening method and the test-negative control designs enable estimating IVE using exclusively SISSS data. (c) 2010 Elsevier Ltd. All rights reserved.

Oxygen Mass Transport in Stented Coronary Arteries.

PubMed

Murphy, Eoin A; Dunne, Adrian S; Martin, David M; Boyle, Fergal J

2016-02-01

Oxygen deficiency, known as hypoxia, in arterial walls has been linked to increased intimal hyperplasia, which is the main adverse biological process causing in-stent restenosis. Stent implantation has significant effects on the oxygen transport into the arterial wall. Elucidating these effects is critical to optimizing future stent designs. In this study the most advanced oxygen transport model developed to date was assessed in two test cases and used to compare three coronary stent designs. Additionally, the predicted results from four simplified blood oxygen transport models are compared in the two test cases. The advanced model showed good agreement with experimental measurements within the mass-transfer boundary layer and at the luminal surface; however, more work is needed in predicting the oxygen transport within the arterial wall. Simplifying the oxygen transport model within the blood flow produces significant errors in predicting the oxygen transport in arteries. This study can be used as a guide for all future numerical studies in this area and the advanced model could provide a powerful tool in aiding design of stents and other cardiovascular devices.

One vs two primary LOX feedline configuration study for the National Launch System

NASA Technical Reports Server (NTRS)

Dill, K.; Davis, D.; Bates, R.; Tarwater, R.

1992-01-01

Six single LOX feedline designs were evaluated for use on the National Launch Vehicle. A single feedline design, designated the 'Spider', was chosen and compared to the baseline system. The baseline configuration employs two 20-inch I.D. lines, each supplying LOX to three 650,000 lbf thrust Space Transportation Main Engines. Five single feedline diameters were examined for the spider configuration; 22, 24, 26, 28, and 30-inch I.D. System dry weights and LOX residuals were estimated. These parameters, along with calculated staged mass for the different single line and baseline configurations, were used to calculate the payload mass to orbit. For the cases where LOX is drained to minimum NPSP conditions, none of the single lines performed as well as the dual line system, although the 22-inch diameter single line compared well. However, for the cases where LOX is drained to operating levels (LOX level at the booster and spider manifolds for the dual and single line configurations, respectively), the 22 - 26-inch I.D. single line systems show a greater payload capability.

[Effectiveness of penile ventral scrotum cohesion place wedge cutting and improved Brisson technique for congenital buried penis].

PubMed

Zhang, Huafeng

2013-09-01

To investigate the effectiveness of the penile ventral scrotum cohesion place wedge cutting and improved Brisson technique for congenital buried penis. Between March 2010 and June 2012, 68 boys with congenital buried penis were treated by the penile ventral scrotum cohesion place wedge cutting and improved Brisson technique, with a median age of 4 years and 10 months (range, 3 months-13 years). Of 68 cases, 14 were classified as phimosis type, 14 as rope belt type, 20 as moderate type, and 20 as severe type. The body of penis developed well and had no deformity. After operation, complications were observed, and the effectiveness was evaluated by the designed questionnaire. Early postoperative complications occurred in 11 cases, including obvious adhesion of the outside wrapping mouth in 4 cases, scrotal skin bloat in 5 cases, and distal foreskin necrosis in 2 cases; long-term complications occurred in 9 cases, including abdominal incision scar formation in 4 cases, wrapping mouth scar stricture in 3 cases, and short penis in 2 cases. Primary healing of incision was obtained in the other boys. Fifty-four cases were followed up 6-12 months (mean, 8 months). According to the designed questionnaire, satisfaction rate with the overall view in parents was 77.78% (42/54); the clinical improvement rate was 85.19% (46/54); exposure of the penis was satisfactory in parents of 50 cases; and the parents had no psychological burden of penis exposure in 46 cases, which were significantly improved when compared with preoperative ones (P < 0.05). The boys had no psychological burden of penis exposure in 29 cases (53.70%) after operation, showing no significant difference when compared with preoperative one (18 cases, 33.33%) (chi2 = 1.22, P = 0.31). Application of the penile ventral scrotum cohesion place wedge cutting and improved Brisson technique can effectively correct congenital buried penis.

Impact of Flipped Classroom Design on Student Performance and Perceptions in a Pharmacotherapy Course.

PubMed

Koo, Cathy L; Demps, Elaine L; Farris, Charlotte; Bowman, John D; Panahi, Ladan; Boyle, Paul

2016-03-25

Objective. To determine whether a flipped classroom design would improve student performance and perceptions of the learning experience compared to traditional lecture course design in a required pharmacotherapy course for second-year pharmacy students. Design. Students viewed short online videos about the foundational concepts and answered self-assessment questions prior to face-to-face sessions involving patient case discussions. Assessment. Pretest/posttest and precourse/postcourse surveys evaluated students' short-term knowledge retention and perceptions before and after the redesigned course. The final grades improved after the redesign. Mean scores on the posttest improved from the pretest. Postcourse survey showed 88% of students were satisfied with the redesign. Students reported that they appreciated the flexibility of video viewing and knowledge application during case discussions but some also struggled with time requirements of the course. Conclusion. The redesigned course improved student test performance and perceptions of the learning experience during the first year of implementation.

Analysis of a mammography teaching program based on an affordance design model.

PubMed

Luo, Ping; Eikman, Edward A; Kealy, William; Qian, Wei

2006-12-01

The wide use of computer technology in education, particularly in mammogram reading, asks for e-learning evaluation. The existing media comparative studies, learner attitude evaluations, and performance tests are problematic. Based on an affordance design model, this study examined an existing e-learning program on mammogram reading. The selection criteria include content relatedness, representativeness, e-learning orientation, image quality, program completeness, and accessibility. A case study was conducted to examine the affordance features, functions, and presentations of the selected software. Data collection and analysis methods include interviews, protocol-based document analysis, and usability tests and inspection. Also some statistics were calculated. The examination of PBE identified that this educational software designed and programmed some tools. The learner can use these tools in the process of optimizing displays, scanning images, comparing different projections, marking the region of interests, constructing a descriptive report, assessing one's learning outcomes, and comparing one's decisions with the experts' decisions. Further, PBE provides some resources for the learner to construct one's knowledge and skills, including a categorized image library, a term-searching function, and some teaching links. Besides, users found it easy to navigate and carry out tasks. The users also reacted positively toward PBE's navigation system, instructional aids, layout, pace and flow of information, graphics, and other presentation design. The software provides learners with some cognitive tools, supporting their perceptual problem-solving processes and extending their capabilities. Learners can internalize the mental models in mammogram reading through multiple perceptual triangulations, sensitization of related features, semantic description of mammogram findings, and expert-guided semantic report construction. The design of these cognitive tools and the software interface matches the findings and principles in human learning and instructional design. Working with PBE's case-based simulations and categorized gallery, learners can enrich and transfer their experience to their jobs.

Certification Examination Cases of Candidates for Certification by the American Board of Plastic Surgery: Trends in Practice Profiles Spanning a Decade (2000–2009)

PubMed Central

Chung, Kevin C.; Song, Jae W.; Shauver, Melissa J.; Cullison, Terry M.; Noone, R. Barrett

2011-01-01

Background To evaluate the case mix of plastic surgeons in their early years of practice by examining candidate case-logs submitted for the Oral Examination. Methods De-identified data from 2000–2009 consisting of case-logs submitted by young plastic surgery candidates for the Oral Examination were analyzed. Data consisted of exam year, CPT (Current Procedural Terminology) Codes and the designation of each CPT code as cosmetic or reconstructive by the candidate, and patient age and gender. Subgroup analyses for comprehensive, cosmetic, craniomaxillofacial, and hand surgery modules were performed by using the CPT code list designated by the American Board of Plastic Surgery Maintenance of Certification in Plastic Surgery ( ) module framework. Results We examined case-logs from a yearly average of 261 candidates over 10 years. Wider variations in yearly percent change in median cosmetic surgery case volumes (−62.5% to 30%) were observed when compared to the reconstructive surgery case volumes (−18.0% to 25.7%). Compared to cosmetic surgery cases per candidate, which varied significantly from year-to-year (p<0.0001), reconstructive surgery cases per candidate did not vary significantly (p=0.954). Subgroup analyses of proportions of types of surgical procedures based on CPT code categories, revealed hand surgery to be the least performed procedure relative to comprehensive, craniomaxillofacial, and cosmetic surgery procedures. Conclusions Graduates of plastic surgery training programs are committed to performing a broad spectrum of reconstructive and cosmetic surgical procedures in their first year of practice. However, hand surgery continues to have a small presence in the practice profiles of young plastic surgeons. PMID:21788850

Design study of toroidal traction CVT for electric vehicles

NASA Technical Reports Server (NTRS)

Raynard, A. E.; Kraus, J.; Bell, D. D.

1980-01-01

The development, evaluation, and optimization of a preliminary design concept for a continuously variable transmission (CVT) to couple the high-speed output shaft of an energy storage flywheel to the drive train of an electric vehicle is discussed. An existing computer simulation program was modified and used to compare the performance of five CVT design configurations. Based on this analysis, a dual-cavity full-toroidal drive with regenerative gearing is selected for the CVT design configuration. Three areas are identified that will require some technological development: the ratio control system, the traction fluid properities, and evaluation of the traction contact performance. Finally, the suitability of the selected CVT design concept for alternate electric and hybrid vehicle applications and alternate vehicle sizes and maximum output torques is determined. In all cases the toroidal traction drive design concept is applicable to the vehicle system. The regenerative gearing could be eliminated in the electric powered vehicle because of the reduced ratio range requirements. In other cases the CVT with regenerative gearing would meet the design requirements after appropriate adjustments in size and reduction gearing ratio.

Increasing Active Student Responding in a University Applied Behavior Analysis Course: The Effect of Daily Assessment and Response Cards on End of Week Quiz Scores

ERIC Educational Resources Information Center

Malanga, Paul R.; Sweeney, William J.

2008-01-01

The study compared the effects of daily assessment and response cards on average weekly quiz scores in an introduction to applied behavior analysis course. An alternating treatments design (Kazdin 1982, "Single-case research designs." New York: Oxford University Press; Cooper et al. 2007, "Applied behavior analysis." Upper Saddle River:…

The United States and Canada: A Common Heritage, a Shared Future.

ERIC Educational Resources Information Center

Blankenship, Glen; And Others

Designed to familiarize students with Canada and how it compares and contrasts with the United States, this collection of 18 lessons is designed to be used in a variety of ways. The lessons may be used individually, infused as case studies into a variety of course topics or used as a complete unit. Each lesson is divided into six sections: lesson…

Design optimization of single mixed refrigerant LNG process using a hybrid modified coordinate descent algorithm

NASA Astrophysics Data System (ADS)

Qyyum, Muhammad Abdul; Long, Nguyen Van Duc; Minh, Le Quang; Lee, Moonyong

2018-01-01

Design optimization of the single mixed refrigerant (SMR) natural gas liquefaction (LNG) process involves highly non-linear interactions between decision variables, constraints, and the objective function. These non-linear interactions lead to an irreversibility, which deteriorates the energy efficiency of the LNG process. In this study, a simple and highly efficient hybrid modified coordinate descent (HMCD) algorithm was proposed to cope with the optimization of the natural gas liquefaction process. The single mixed refrigerant process was modeled in Aspen Hysys® and then connected to a Microsoft Visual Studio environment. The proposed optimization algorithm provided an improved result compared to the other existing methodologies to find the optimal condition of the complex mixed refrigerant natural gas liquefaction process. By applying the proposed optimization algorithm, the SMR process can be designed with the 0.2555 kW specific compression power which is equivalent to 44.3% energy saving as compared to the base case. Furthermore, in terms of coefficient of performance (COP), it can be enhanced up to 34.7% as compared to the base case. The proposed optimization algorithm provides a deep understanding of the optimization of the liquefaction process in both technical and numerical perspectives. In addition, the HMCD algorithm can be employed to any mixed refrigerant based liquefaction process in the natural gas industry.

Comparative audit of clinical research in pediatric neurology.

PubMed

Al-Futaisi, Amna; Shevell, Michael

2004-11-01

Clinical research involves direct observation or data collection on human subjects. This study was conducted to evaluate the profile of pediatric neurology clinical research over a decade. Trends in pediatric neurology clinical research were documented through a systematic comparative review of articles published in selected journals. Eleven journals (five pediatric neurology, three general neurology, three general pediatrics) were systematically reviewed for articles involving a majority of human subjects less than 18 years of age for the years 1990 and 2000. Three hundred thirty-five clinical research articles in pediatric neurology were identified in the 11 journals for 1990 and 398 for 2000, a 19% increase. A statistically significant increase in analytic design (21.8% vs 39.5%; P = .01), statistical support (6% vs 16.6%; P < .0001), and multidisciplinary team (69.9% vs 87%; P = .003) was observed. In terms of specific study design, a significant decline in case reports (34.3% vs 10.3%; P < .0001) and an increase in case-control studies (11.3% vs 22.9%; P = .02) were evident over the 10-year interval. This comparative audit revealed that there has been a discernible change in the methodology profile of clinical research in child neurology over a decade. Trends apparently suggest a more rigorous approach to study design and investigation in this field.

Exposure enriched outcome dependent designs for longitudinal studies of gene-environment interaction.

PubMed

Sun, Zhichao; Mukherjee, Bhramar; Estes, Jason P; Vokonas, Pantel S; Park, Sung Kyun

2017-08-15

Joint effects of genetic and environmental factors have been increasingly recognized in the development of many complex human diseases. Despite the popularity of case-control and case-only designs, longitudinal cohort studies that can capture time-varying outcome and exposure information have long been recommended for gene-environment (G × E) interactions. To date, literature on sampling designs for longitudinal studies of G × E interaction is quite limited. We therefore consider designs that can prioritize a subsample of the existing cohort for retrospective genotyping on the basis of currently available outcome, exposure, and covariate data. In this work, we propose stratified sampling based on summaries of individual exposures and outcome trajectories and develop a full conditional likelihood approach for estimation that adjusts for the biased sample. We compare the performance of our proposed design and analysis with combinations of different sampling designs and estimation approaches via simulation. We observe that the full conditional likelihood provides improved estimates for the G × E interaction and joint exposure effects over uncorrected complete-case analysis, and the exposure enriched outcome trajectory dependent design outperforms other designs in terms of estimation efficiency and power for detection of the G × E interaction. We also illustrate our design and analysis using data from the Normative Aging Study, an ongoing longitudinal cohort study initiated by the Veterans Administration in 1963. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Improved system integration for integrated gasification combined cycle (IGCC) systems.

PubMed

Frey, H Christopher; Zhu, Yunhua

2006-03-01

Integrated gasification combined cycle (IGCC) systems are a promising technology for power generation. They include an air separation unit (ASU), a gasification system, and a gas turbine combined cycle power block, and feature competitive efficiency and lower emissions compared to conventional power generation technology. IGCC systems are not yet in widespread commercial use and opportunities remain to improve system feasibility via improved process integration. A process simulation model was developed for IGCC systems with alternative types of ASU and gas turbine integration. The model is applied to evaluate integration schemes involving nitrogen injection, air extraction, and combinations of both, as well as different ASU pressure levels. The optimal nitrogen injection only case in combination with an elevated pressure ASU had the highest efficiency and power output and approximately the lowest emissions per unit output of all cases considered, and thus is a recommended design option. The optimal combination of air extraction coupled with nitrogen injection had slightly worse efficiency, power output, and emissions than the optimal nitrogen injection only case. Air extraction alone typically produced lower efficiency, lower power output, and higher emissions than all other cases. The recommended nitrogen injection only case is estimated to provide annualized cost savings compared to a nonintegrated design. Process simulation modeling is shown to be a useful tool for evaluation and screening of technology options.

The application of SVR model in the improvement of QbD: a case study of the extraction of podophyllotoxin.

PubMed

Zhai, Chun-Hui; Xuan, Jian-Bang; Fan, Hai-Liu; Zhao, Teng-Fei; Jiang, Jian-Lan

2018-05-03

In order to make a further optimization of process design via increasing the stability of design space, we brought in the model of Support Vector Regression (SVR). In this work, the extraction of podophyllotoxin was researched as a case study based on Quality by Design (QbD). We compared the fitting effect of SVR and the most used quadratic polynomial model (QPM) in QbD, and an analysis was made between the two design spaces obtained by SVR and QPM. As a result, the SVR stayed ahead of QPM in prediction accuracy, the stability of model and the generalization ability. The introduction of SVR into QbD made the extraction process of podophyllotoxin well designed and easier to control. The better fitting effect of SVR improved the application effect of QbD and the universal applicability of SVR, especially for non-linear, complicated and weak-regularity problems, widened the application field of QbD.

Wired.

ERIC Educational Resources Information Center

Conklin, Aaron R.

1998-01-01

Discusses technology's impact on scoreboard design: the development of the light-emitting diode (LED) display. How the LED system works is explained, as are the advantages and disadvantages of LED compared with incandescent lamp boards. Final comments address deciding on materials for scoreboard casings. (GR)

Comparing effects of fire modeling methods on simulated fire patterns and succession: a case study in the Missouri Ozarks

Treesearch

Jian Yang; Hong S. He; Brian R. Sturtevant; Brian R. Miranda; Eric J. Gustafson

2008-01-01

We compared four fire spread simulation methods (completely random, dynamic percolation. size-based minimum travel time algorithm. and duration-based minimum travel time algorithm) and two fire occurrence simulation methods (Poisson fire frequency model and hierarchical fire frequency model) using a two-way factorial design. We examined these treatment effects on...

Organisational design for an integrated oncological department

PubMed Central

Meiss-de Haas, Ch.L.; Falkmann, H.; Douma, J.; van Gassel, J.G.; Peters, W.G.; van Mierlo, R.; van Turnhout, J.M.; Verhagen, C.A.H.H.V.M.; Schrijvers, A.J.P.

2001-01-01

Abstract Objective The outcomes of a Strength, Weakness, Opportunities and Threat (SWOT) analysis of three Integrated Oncological Departments were compared with their present situation three years later to define factors that can influence a successful implementation and development of an Integrated Oncological Department in- and outside (i.e. home care) the hospital. Research design Comparative Qualitative Case Study. Methods Auditing based on care-as-usual norms by an external, experienced auditing committee. Research setting Integrated Oncological Departments of three hospitals. Results Successful multidisciplinary care in an integrated, oncological department needs broad support inside the hospital and a well-defined organisational plan. PMID:16896411

User-composable Electronic Health Record Improves Efficiency of Clinician Data Viewing for Patient Case Appraisal: A Mixed-Methods Study.

PubMed

Senathirajah, Yalini; Kaufman, David; Bakken, Suzanne

2016-01-01

Challenges in the design of electronic health records (EHRs) include designing usable systems that must meet the complex, rapidly changing, and high-stakes information needs of clinicians. The ability to move and assemble elements together on the same page has significant human-computer interaction (HCI) and efficiency advantages, and can mitigate the problems of negotiating multiple fixed screens and the associated cognitive burdens. We compare MedWISE-a novel EHR that supports user-composable displays-with a conventional EHR in terms of the number of repeat views of data elements for patient case appraisal. The study used mixed-methods for examination of clinical data viewing in four patient cases. The study compared use of an experimental user-composable EHR with use of a conventional EHR, for case appraisal. Eleven clinicians used a user-composable EHR in a case appraisal task in the laboratory setting. This was compared with log file analysis of the same patient cases in the conventional EHR. We investigated the number of repeat views of the same clinical information during a session and across these two contexts, and compared them using Fisher's exact test. There was a significant difference (p<.0001) in proportion of cases with repeat data element viewing between the user-composable EHR (14.6 percent) and conventional EHR (72.6 percent). Users of conventional EHRs repeatedly viewed the same information elements in the same session, as revealed by log files. Our findings are consistent with the hypothesis that conventional systems require that the user view many screens and remember information between screens, causing the user to forget information and to have to access the information a second time. Other mechanisms (such as reduction in navigation over a population of users due to interface sharing, and information selection) may also contribute to increased efficiency in the experimental system. Systems that allow a composable approach that enables the user to gather together on the same screen any desired information elements may confer cognitive support benefits that can increase productive use of systems by reducing fragmented information. By reducing cognitive overload, it can also enhance the user experience.

An ontology-driven, case-based clinical decision support model for removable partial denture design

NASA Astrophysics Data System (ADS)

Chen, Qingxiao; Wu, Ji; Li, Shusen; Lyu, Peijun; Wang, Yong; Li, Miao

2016-06-01

We present the initial work toward developing a clinical decision support model for specific design of removable partial dentures (RPDs) in dentistry. We developed an ontological paradigm to represent knowledge of a patient’s oral conditions and denture component parts. During the case-based reasoning process, a cosine similarity algorithm was applied to calculate similarity values between input patients and standard ontology cases. A group of designs from the most similar cases were output as the final results. To evaluate this model, the output designs of RPDs for 104 randomly selected patients were compared with those selected by professionals. An area under the curve of the receiver operating characteristic (AUC-ROC) was created by plotting true-positive rates against the false-positive rate at various threshold settings. The precision at position 5 of the retrieved cases was 0.67 and at the top of the curve it was 0.96, both of which are very high. The mean average of precision (MAP) was 0.61 and the normalized discounted cumulative gain (NDCG) was 0.74 both of which confirmed the efficient performance of our model. All the metrics demonstrated the efficiency of our model. This methodology merits further research development to match clinical applications for designing RPDs. This paper is organized as follows. After the introduction and description of the basis for the paper, the evaluation and results are presented in Section 2. Section 3 provides a discussion of the methodology and results. Section 4 describes the details of the ontology, similarity algorithm, and application.

An ontology-driven, case-based clinical decision support model for removable partial denture design.

PubMed

Chen, Qingxiao; Wu, Ji; Li, Shusen; Lyu, Peijun; Wang, Yong; Li, Miao

2016-06-14

We present the initial work toward developing a clinical decision support model for specific design of removable partial dentures (RPDs) in dentistry. We developed an ontological paradigm to represent knowledge of a patient's oral conditions and denture component parts. During the case-based reasoning process, a cosine similarity algorithm was applied to calculate similarity values between input patients and standard ontology cases. A group of designs from the most similar cases were output as the final results. To evaluate this model, the output designs of RPDs for 104 randomly selected patients were compared with those selected by professionals. An area under the curve of the receiver operating characteristic (AUC-ROC) was created by plotting true-positive rates against the false-positive rate at various threshold settings. The precision at position 5 of the retrieved cases was 0.67 and at the top of the curve it was 0.96, both of which are very high. The mean average of precision (MAP) was 0.61 and the normalized discounted cumulative gain (NDCG) was 0.74 both of which confirmed the efficient performance of our model. All the metrics demonstrated the efficiency of our model. This methodology merits further research development to match clinical applications for designing RPDs. This paper is organized as follows. After the introduction and description of the basis for the paper, the evaluation and results are presented in Section 2. Section 3 provides a discussion of the methodology and results. Section 4 describes the details of the ontology, similarity algorithm, and application.

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.

An approach to checking case-crossover analyses based on equivalence with time-series methods.

PubMed

Lu, Yun; Symons, James Morel; Geyh, Alison S; Zeger, Scott L

2008-03-01

The case-crossover design has been increasingly applied to epidemiologic investigations of acute adverse health effects associated with ambient air pollution. The correspondence of the design to that of matched case-control studies makes it inferentially appealing for epidemiologic studies. Case-crossover analyses generally use conditional logistic regression modeling. This technique is equivalent to time-series log-linear regression models when there is a common exposure across individuals, as in air pollution studies. Previous methods for obtaining unbiased estimates for case-crossover analyses have assumed that time-varying risk factors are constant within reference windows. In this paper, we rely on the connection between case-crossover and time-series methods to illustrate model-checking procedures from log-linear model diagnostics for time-stratified case-crossover analyses. Additionally, we compare the relative performance of the time-stratified case-crossover approach to time-series methods under 3 simulated scenarios representing different temporal patterns of daily mortality associated with air pollution in Chicago, Illinois, during 1995 and 1996. Whenever a model-be it time-series or case-crossover-fails to account appropriately for fluctuations in time that confound the exposure, the effect estimate will be biased. It is therefore important to perform model-checking in time-stratified case-crossover analyses rather than assume the estimator is unbiased.

A general approach for sample size calculation for the three-arm 'gold standard' non-inferiority design.

PubMed

Stucke, Kathrin; Kieser, Meinhard

2012-12-10

In the three-arm 'gold standard' non-inferiority design, an experimental treatment, an active reference, and a placebo are compared. This design is becoming increasingly popular, and it is, whenever feasible, recommended for use by regulatory guidelines. We provide a general method to calculate the required sample size for clinical trials performed in this design. As special cases, the situations of continuous, binary, and Poisson distributed outcomes are explored. Taking into account the correlation structure of the involved test statistics, the proposed approach leads to considerable savings in sample size as compared with application of ad hoc methods for all three scale levels. Furthermore, optimal sample size allocation ratios are determined that result in markedly smaller total sample sizes as compared with equal assignment. As optimal allocation makes the active treatment groups larger than the placebo group, implementation of the proposed approach is also desirable from an ethical viewpoint. Copyright © 2012 John Wiley & Sons, Ltd.

Bayesian Optimal Interval Design: A Simple and Well-Performing Design for Phase I Oncology Trials

PubMed Central

Yuan, Ying; Hess, Kenneth R.; Hilsenbeck, Susan G.; Gilbert, Mark R.

2016-01-01

Despite more than two decades of publications that offer more innovative model-based designs, the classical 3+3 design remains the most dominant phase I trial design in practice. In this article, we introduce a new trial design, the Bayesian optimal interval (BOIN) design. The BOIN design is easy to implement in a way similar to the 3+3 design, but is more flexible for choosing the target toxicity rate and cohort size and yields a substantially better performance that is comparable to that of more complex model-based designs. The BOIN design contains the 3+3 design and the accelerated titration design as special cases, thus linking it to established phase I approaches. A numerical study shows that the BOIN design generally outperforms the 3+3 design and the modified toxicity probability interval (mTPI) design. The BOIN design is more likely than the 3+3 design to correctly select the maximum tolerated dose (MTD) and allocate more patients to the MTD. Compared to the mTPI design, the BOIN design has a substantially lower risk of overdosing patients and generally a higher probability of correctly selecting the MTD. User-friendly software is freely available to facilitate the application of the BOIN design. PMID:27407096

Audit method suited for DSS in clinical environment.

PubMed

Vicente, Javier

2015-01-01

This chapter presents a novel online method to audit predictive models using a Bayesian perspective. The auditing model has been specifically designed for Decision Support Systems (DSSs) suited for clinical or research environments. Taking as starting point the working diagnosis supplied by the clinician, this method compares and evaluates the predictive skills of those models able to answer to that diagnosis. The approach consists in calculating the posterior odds of a model through the composition of a prior odds, a static odds, and a dynamic odds. To do so, this method estimates the posterior odds from the cases that the comparing models had in common during the design stage and from the cases already viewed by the DSS after deployment in the clinical site. In addition, if an ontology of the classes is available, this method can audit models answering related questions, which offers a reinforcement to the decisions the user already took and gives orientation on further diagnostic steps.The main technical novelty of this approach lies in the design of an audit model adapted to suit the decision workflow of a clinical environment. The audit model allows deciding what is the classifier that best suits each particular case under evaluation and allows the detection of possible misbehaviours due to population differences or data shifts in the clinical site. We show the efficacy of our method for the problem of brain tumor diagnosis with Magnetic Resonance Spectroscopy (MRS).

Evolutionary and Comparative Genomics to Drive Rational Drug Design, with Particular Focus on Neuropeptide Seven-Transmembrane Receptors.

PubMed

Furlong, Michael; Seong, Jae Young

2017-01-01

Seven transmembrane receptors (7TMRs), also known as G protein-coupled receptors, are popular targets of drug development, particularly 7TMR systems that are activated by peptide ligands. Although many pharmaceutical drugs have been discovered via conventional bulk analysis techniques the increasing availability of structural and evolutionary data are facilitating change to rational, targeted drug design. This article discusses the appeal of neuropeptide-7TMR systems as drug targets and provides an overview of concepts in the evolution of vertebrate genomes and gene families. Subsequently, methods that use evolutionary concepts and comparative analysis techniques to aid in gene discovery, gene function identification, and novel drug design are provided along with case study examples.

Evolutionary and Comparative Genomics to Drive Rational Drug Design, with Particular Focus on Neuropeptide Seven-Transmembrane Receptors

PubMed Central

Furlong, Michael; Seong, Jae Young

2017-01-01

Seven transmembrane receptors (7TMRs), also known as G protein-coupled receptors, are popular targets of drug development, particularly 7TMR systems that are activated by peptide ligands. Although many pharmaceutical drugs have been discovered via conventional bulk analysis techniques the increasing availability of structural and evolutionary data are facilitating change to rational, targeted drug design. This article discusses the appeal of neuropeptide-7TMR systems as drug targets and provides an overview of concepts in the evolution of vertebrate genomes and gene families. Subsequently, methods that use evolutionary concepts and comparative analysis techniques to aid in gene discovery, gene function identification, and novel drug design are provided along with case study examples. PMID:28035082

Design of Stripping Columns Applied to Drinking Water to Minimize Carcinogenic Risk from Trihalomethanes (THMs)

PubMed Central

Canosa, Joel

2018-01-01

The aim of this study is the application of a software tool to the design of stripping columns to calculate the removal of trihalomethanes (THMs) from drinking water. The tool also allows calculating the rough capital cost of the column and the decrease in carcinogenic risk indeces associated with the elimination of THMs and, thus, the investment to save a human life. The design of stripping columns includes the determination, among other factors, of the height (HOG), the theoretical number of plates (NOG), and the section (S) of the columns based on the study of pressure drop. These results have been compared with THM stripping literature values, showing that simulation is sufficiently conservative. Three case studies were chosen to apply the developed software. The first case study was representative of small-scale application to a community in Córdoba (Spain) where chloroform is predominant and has a low concentration. The second case study was of an intermediate scale in a region in Venezuela, and the third case study was representative of large-scale treatment of water in the Barcelona metropolitan region (Spain). Results showed that case studies with larger scale and higher initial risk offer the best capital investment to decrease the risk. PMID:29562670

Analysis and meta-analysis of single-case designs with a standardized mean difference statistic: a primer and applications.

PubMed

Shadish, William R; Hedges, Larry V; Pustejovsky, James E

2014-04-01

This article presents a d-statistic for single-case designs that is in the same metric as the d-statistic used in between-subjects designs such as randomized experiments and offers some reasons why such a statistic would be useful in SCD research. The d has a formal statistical development, is accompanied by appropriate power analyses, and can be estimated using user-friendly SPSS macros. We discuss both advantages and disadvantages of d compared to other approaches such as previous d-statistics, overlap statistics, and multilevel modeling. It requires at least three cases for computation and assumes normally distributed outcomes and stationarity, assumptions that are discussed in some detail. We also show how to test these assumptions. The core of the article then demonstrates in depth how to compute d for one study, including estimation of the autocorrelation and the ratio of between case variance to total variance (between case plus within case variance), how to compute power using a macro, and how to use the d to conduct a meta-analysis of studies using single-case designs in the free program R, including syntax in an appendix. This syntax includes how to read data, compute fixed and random effect average effect sizes, prepare a forest plot and a cumulative meta-analysis, estimate various influence statistics to identify studies contributing to heterogeneity and effect size, and do various kinds of publication bias analyses. This d may prove useful for both the analysis and meta-analysis of data from SCDs. Copyright © 2013 Society for the Study of School Psychology. Published by Elsevier Ltd. All rights reserved.

The Development of a Curriculum for Renewable Energy: A Case Study of Charcoal Briquettes from Agricultural Residues for Environmental Literacy of Secondary School Students at Samaki Wittaya Municipality School

ERIC Educational Resources Information Center

Klakayan, Jagree; Singseewo, Adisak

2016-01-01

This research aimed to (1) design a curriculum on Production of Charcoal Briquettes from Agricultural Residues, (2) implement the designed curriculum, and (3) study and compare the learning achievements of Matthayomsuksa 3 students at Samakee Wittaya Municipality School in terms of knowledge, learning skills, and participation in the production of…

Rotavirus vaccine effectiveness in low-income settings: An evaluation of the test-negative design.

PubMed

Schwartz, Lauren M; Halloran, M Elizabeth; Rowhani-Rahbar, Ali; Neuzil, Kathleen M; Victor, John C

2017-01-03

The test-negative design (TND), an epidemiologic method currently used to measure rotavirus vaccine (RV) effectiveness, compares the vaccination status of rotavirus-positive cases and rotavirus-negative controls meeting a pre-defined case definition for acute gastroenteritis. Despite the use of this study design in low-income settings, the TND has not been evaluated to measure rotavirus vaccine effectiveness. This study builds upon prior methods to evaluate the use of the TND for influenza vaccine using a randomized controlled clinical trial database. Test-negative vaccine effectiveness (VE-TND) estimates were derived from three large randomized placebo-controlled trials (RCTs) of monovalent (RV1) and pentavalent (RV5) rotavirus vaccines in sub-Saharan Africa and Asia. Derived VE-TND estimates were compared to the original RCT vaccine efficacy estimates (VE-RCTs). The core assumption of the TND (i.e., rotavirus vaccine has no effect on rotavirus-negative diarrhea) was also assessed. TND vaccine effectiveness estimates were nearly equivalent to original RCT vaccine efficacy estimates. Neither RV had a substantial effect on rotavirus-negative diarrhea. This study supports the TND as an appropriate epidemiologic study design to measure rotavirus vaccine effectiveness in low-income settings. Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Life cycle design metrics for energy generation technologies: Method, data, and case study

NASA Astrophysics Data System (ADS)

Cooper, Joyce; Lee, Seung-Jin; Elter, John; Boussu, Jeff; Boman, Sarah

A method to assist in the rapid preparation of Life Cycle Assessments of emerging energy generation technologies is presented and applied to distributed proton exchange membrane fuel cell systems. The method develops life cycle environmental design metrics and allows variations in hardware materials, transportation scenarios, assembly energy use, operating performance and consumables, and fuels and fuel production scenarios to be modeled and comparisons to competing systems to be made. Data and results are based on publicly available U.S. Life Cycle Assessment data sources and are formulated to allow the environmental impact weighting scheme to be specified. A case study evaluates improvements in efficiency and in materials recycling and compares distributed proton exchange membrane fuel cell systems to other distributed generation options. The results reveal the importance of sensitivity analysis and system efficiency in interpreting case studies.

A voyage to Mars: A challenge to collaboration between man and machines

NASA Technical Reports Server (NTRS)

Statler, Irving C.

1991-01-01

A speech addressing the design of man machine systems for exploration of space beyond Earth orbit from the human factors perspective is presented. Concerns relative to the design of automated and intelligent systems for the NASA Space Exploration Initiative (SEI) missions are largely based on experiences with integrating humans and comparable systems in aviation. The history, present status, and future prospect, of human factors in machine design are discussed in relation to a manned voyage to Mars. Three different cases for design philosophy are presented. The use of simulation is discussed. Recommendations for required research are given.

Design and Evaluation of Glass/epoxy Composite Blade and Composite Tower Applied to Wind Turbine

NASA Astrophysics Data System (ADS)

Park, Hyunbum

2018-02-01

In the study, the analysis and manufacturing of small class wind turbine blade was performed. In the structural design, firstly the loading conditions are defined through the load case analysis. The proposed structural configuration of blade has a sandwich type composite structure with the E-glass/Epoxy face sheets and the Urethane foam core for lightness, structural stability, low manufacturing cost and easy manufacturing process. And also, this work proposes a design procedure and results of tower for the small scale wind turbine systems. Structural analysis of blade including load cases, stress, deformation, buckling, vibration and fatigue life was performed using the finite element method, the load spectrum analysis and the Miner rule. Moreover, investigation on structural safety of tower was verified through structural analysis by FEM. The manufacturing of blade and tower was performed based on structural design. In order to investigate the designed structure, the structural tests were conducted and its results were compared with the calculated results. It is confirmed that the final proposed blade and tower meet the design requirements.

Snippets from the past: is Flint, Michigan, the birthplace of the case-control study?

PubMed

Morabia, Alfredo

2013-12-15

In the summer of 1924, an outbreak of scarlet fever occurred in Flint, Michigan. Unable to trace it to the usual causes, particularly fresh milk, the Michigan Department of Health used a novel approach to disentangle the enigma: The 116 cases of scarlet fever were compared with 117 "controls" selected from neighbors of the quarantined cases and from patients at the City Health Center who had been treated for ailments unrelated to scarlet fever. The extraordinary culprit was ice cream, which had a frequent/occasional/none consumption prevalence of 60%, 34%, and 6% among the cases and 24%, 51%, and 25% among the controls, respectively. The 1925 report reads, "Detailed epidemiological investigation, by means of case histories and control histories on well persons, confirmed early suspicions and established the fact that the epidemic was spread by ice cream" (Am J Hyg. 1925;5(5):669-681). This forgotten epidemiologic study is the oldest study using the case-control design to have been resurrected thus far. The case-control study design may have been conceived simultaneously, but independently and for different purposes, in England (Janet Lane-Claypon's 1926 report on the determinants of breast cancer) and the United States.

Parametric study of prospective early commercial MHD power plants (PSPEC). General Electric Company, task 1: Parametric analysis

NASA Technical Reports Server (NTRS)

Marston, C. H.; Alyea, F. N.; Bender, D. J.; Davis, L. K.; Dellinger, T. C.; Hnat, J. G.; Komito, E. H.; Peterson, C. A.; Rogers, D. A.; Roman, A. J.

1980-01-01

The performance and cost of moderate technology coal-fired open cycle MHD/steam power plant designs which can be expected to require a shorter development time and have a lower development cost than previously considered mature OCMHD/steam plants were determined. Three base cases were considered: an indirectly-fired high temperature air heater (HTAH) subsystem delivering air at 2700 F, fired by a state of the art atmospheric pressure gasifier, and the HTAH subsystem was deleted and oxygen enrichment was used to obtain requisite MHD combustion temperature. Coal pile to bus bar efficiencies in ease case 1 ranged from 41.4% to 42.9%, and cost of electricity (COE) was highest of the three base cases. For base case 2 the efficiency range was 42.0% to 45.6%, and COE was lowest. For base case 3 the efficiency range was 42.9% to 44.4%, and COE was intermediate. The best parametric cases in bases cases 2 and 3 are recommended for conceptual design. Eventual choice between these approaches is dependent on further evaluation of the tradeoffs among HTAH development risk, O2 plant integration, and further refinements of comparative costs.

Hybrid-Wing-Body Vehicle Composite Fuselage Analysis and Case Study

NASA Technical Reports Server (NTRS)

Mukhopadhyay, Vivek

2014-01-01

Recent progress in the structural analysis of a Hybrid Wing-Body (HWB) fuselage concept is presented with the objective of structural weight reduction under a set of critical design loads. This pressurized efficient HWB fuselage design is presently being investigated by the NASA Environmentally Responsible Aviation (ERA) project in collaboration with the Boeing Company, Huntington Beach. The Pultruded Rod-Stiffened Efficient Unitized Structure (PRSEUS) composite concept, developed at the Boeing Company, is approximately modeled for an analytical study and finite element analysis. Stiffened plate linear theories are employed for a parametric case study. Maximum deflection and stress levels are obtained with appropriate assumptions for a set of feasible stiffened panel configurations. An analytical parametric case study is presented to examine the effects of discrete stiffener spacing and skin thickness on structural weight, deflection and stress. A finite-element model (FEM) of an integrated fuselage section with bulkhead is developed for an independent assessment. Stress analysis and scenario based case studies are conducted for design improvement. The FEM model specific weight of the improved fuselage concept is computed and compared to previous studies, in order to assess the relative weight/strength advantages of this advanced composite airframe technology

The influence of prototype testing in three-dimensional aortic models on fenestrated endograft design.

PubMed

Taher, Fadi; Falkensammer, Juergen; McCarte, Jamie; Strassegger, Johann; Uhlmann, Miriam; Schuch, Philipp; Assadian, Afshin

2017-06-01

The fenestrated Anaconda endograft (Vascutek/Terumo, Inchinnan, UK) is intended for the treatment of abdominal aortic aneurysms with an insufficient infrarenal landing zone. The endografts are custom-made with use of high-resolution, 1-mm-slice computed tomography angiography images. For every case, a nonsterile prototype and a three-dimensional (3D) model of the patient's aorta are constructed to allow the engineers as well as the physician to test-implant the device and to review the fit of the graft. The aim of this investigation was to assess the impact of 3D model construction and prototype testing on the design of the final sterile endograft. A prospectively held database on fenestrated endovascular aortic repair patients treated at a single institution was completed with data from the Vascutek engineers' prototype test results as well as the product request forms. Changes to endograft design based on prototype testing were assessed and are reported for all procedures. Between April 1, 2013, and August 18, 2015, 60 fenestrated Anaconda devices were implanted. Through prototype testing, engineers were able to identify and report potential risks to technical success related to use of the custom device for the respective patient. Theoretical concerns about endograft fit in the rigid model were expressed in 51 cases (85.0%), and the engineers suggested potential changes to the design of 21 grafts (35.0%). Thirteen cases (21.7%) were eventually modified after the surgeon's testing of the prototype. A second prototype was ordered in three cases (5.0%) because of extensive changes to endograft design, such as inclusion of an additional fenestration. Technical success rates were comparable for grafts that showed a perfect fit from the beginning and cases in which prototype testing resulted in a modification of graft design. Planning and construction of fenestrated endografts for complex aortic anatomies where exact fit and positioning of the graft are paramount to allow cannulation of the aortic branches are challenging. In the current series, approximately one in five endografts was modified after prototype testing in an aortic model. Eventually, success rates were comparable between the groups of patients with a good primary prototype fit and those in which the endograft design was altered. Prototype testing in 3D aortic models is a valuable tool to test the fit of a custom-made endograft before implantation. This may help avoid potentially debilitating adverse events associated with misaligned fenestrations and unconnected aortic branches. Copyright © 2016 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

The use of administrative health care databases to identify patients with rheumatoid arthritis

PubMed Central

Hanly, John G; Thompson, Kara; Skedgel, Chris

2015-01-01

Objective To validate and compare the decision rules to identify rheumatoid arthritis (RA) in administrative databases. Methods A study was performed using administrative health care data from a population of 1 million people who had access to universal health care. Information was available on hospital discharge abstracts and physician billings. RA cases in health administrative databases were matched 1:4 by age and sex to randomly selected controls without inflammatory arthritis. Seven case definitions were applied to identify RA cases in the health administrative data, and their performance was compared with the diagnosis by a rheumatologist. The validation study was conducted on a sample of individuals with administrative data who received a rheumatologist consultation at the Arthritis Center of Nova Scotia. Results We identified 535 RA cases and 2,140 non-RA, noninflammatory arthritis controls. Using the rheumatologist’s diagnosis as the gold standard, the overall accuracy of the case definitions for RA cases varied between 68.9% and 82.9% with a kappa statistic between 0.26 and 0.53. The sensitivity and specificity varied from 20.7% to 94.8% and 62.5% to 98.5%, respectively. In a reference population of 1 million, the estimated annual number of incident cases of RA was between 176 and 1,610 and the annual number of prevalent cases was between 1,384 and 5,722. Conclusion The accuracy of case definitions for the identification of RA cases from rheumatology clinics using administrative health care databases is variable when compared to a rheumatologist’s assessment. This should be considered when comparing results across studies. This variability may also be used as an advantage in different study designs, depending on the relative importance of sensitivity and specificity for identifying the population of interest to the research question. PMID:27790047

The Influence of Mother Tongue and Gender on the Acquisition of English (L2). The Case of Afrikaans in Windhoek Schools, Namibia

ERIC Educational Resources Information Center

van Wyk, Jacolynn; Mostert, Maria Louise

2016-01-01

This study investigated the effect of mother tongue instruction and gender on second language acquisition using a causal-comparative quantitative research design. The two distinguishing groups compared were (i) learners that were taught in their mother tongue (Afrikaans) and (ii) learners that were not taught in their mother tongue but in English,…

Enhancing Appropriate Social Behaviors for Children with Autism in General Education Classrooms: An Analysis of Six Cases

ERIC Educational Resources Information Center

Yang, Nancy Kueifen; Schaller, James L.; Huang, Tzu-Ai; Wang, Meei Huey; Tsai, Shu-Fei

2003-01-01

This study compares generalized effects of a social-emotional skills training for girls and boys with autism in resource rooms on promoting positive social behaviors in general education classrooms in Taiwan. A single subject design was used to compare outcomes for 2 girls and 2 boys with autism in the experimental group with 2 boys with autism in…

Exploring Chaos: A Case Study.

ERIC Educational Resources Information Center

Nemirovsky, Ricardo; Tinker, Robert

1993-01-01

Describes software, hardware, and devices that were designed to provide students with an environment to experiment with basic ideas of mechanics, including nonlinear dynamics. Examines the behavior of a Lorenzian water wheel by comparing experimental data with theoretical results obtained from computer-based sensors. (MDH)

Novel Framework for Reduced Order Modeling of Aero-engine Components

NASA Astrophysics Data System (ADS)

Safi, Ali

The present study focuses on the popular dynamic reduction methods used in design of complex assemblies (millions of Degrees of Freedom) where numerous iterations are involved to achieve the final design. Aerospace manufacturers such as Rolls Royce and Pratt & Whitney are actively seeking techniques that reduce computational time while maintaining accuracy of the models. This involves modal analysis of components with complex geometries to determine the dynamic behavior due to non-linearity and complicated loading conditions. In such a case the sub-structuring and dynamic reduction techniques prove to be an efficient tool to reduce design cycle time. The components whose designs are finalized can be dynamically reduced to mass and stiffness matrices at the boundary nodes in the assembly. These matrices conserve the dynamics of the component in the assembly, and thus avoid repeated calculations during the analysis runs for design modification of other components. This thesis presents a novel framework in terms of modeling and meshing of any complex structure, in this case an aero-engine casing. In this study the affect of meshing techniques on the run time are highlighted. The modal analysis is carried out using an extremely fine mesh to ensure all minor details in the structure are captured correctly in the Finite Element (FE) model. This is used as the reference model, to compare against the results of the reduced model. The study also shows the conditions/criteria under which dynamic reduction can be implemented effectively, proving the accuracy of Criag-Bampton (C.B.) method and limitations of Static Condensation. The study highlights the longer runtime needed to produce the reduced matrices of components compared to the overall runtime of the complete unreduced model. Although once the components are reduced, the assembly run is significantly. Hence the decision to use Component Mode Synthesis (CMS) is to be taken judiciously considering the number of iterations that may be required during the design cycle.

Genome profiling of ovarian adenocarcinomas using pangenomic BACs microarray comparative genomic hybridization

PubMed Central

Caserta, Donatella; Benkhalifa, Moncef; Baldi, Marina; Fiorentino, Francesco; Qumsiyeh, Mazin; Moscarini, Massimo

2008-01-01

Background Routine cytogenetic investigations for ovarian cancers are limited by culture failure and poor growth of cancer cells compared to normal cells. Fluorescence in situ Hybridization (FISH) application or classical comparative genome hybridization techniques are also have their own limitations in detecting genome imbalance especially for small changes that are not known ahead of time and for which FISH probes could not be thus designed. Methods We applied microarray comparative genomic hybridization (A-CGH) using one mega base BAC arrays to investigate chromosomal disorders in ovarian adenocarcinoma in patients with familial history. Results Our data on 10 cases of ovarian cancer revealed losses of 6q (4 cases mainly mosaic loss), 9p (4 cases), 10q (3 cases), 21q (3 cases), 22q (4 cases) with association to a monosomy X and gains of 8q and 9q (occurring together in 8 cases) and gain of 12p. There were other abnormalities such as loss of 17p that were noted in two profiles of the studied cases. Total or mosaic segmental gain of 2p, 3q, 4q, 7q and 13q were also observed. Seven of 10 patients were investigated by FISH to control array CGH results. The FISH data showed a concordance between the 2 methods. Conclusion The data suggest that A-CGH detects unique and common abnormalities with certain exceptions such as tetraploidy and balanced translocation, which may lead to understanding progression of genetic changes as well as aid in early diagnosis and have an impact on therapy and prognosis. PMID:18492273

The physical environment and patients' activities and care: A comparative case study at three newly built stroke units.

PubMed

Anåker, Anna; von Koch, Lena; Sjöstrand, Christina; Heylighen, Ann; Elf, Marie

2018-04-20

To explore and compare the impact of the physical environment on patients' activities and care at three newly built stroke units. Receiving care in a stroke unit instead of in a general ward reduces the odds of death, dependency and institutionalized care. In stroke units, the design of the physical environment should support evidence-based care. Studies on patients' activities in relation to the design of the physical environment of stroke units are scarce. This work is a comparative descriptive case study. Patients (N = 55) who had a confirmed diagnosis of stroke were recruited from three newly built stroke units in Sweden. The units were examined by non-participant observation using two types of data collection: behavioural mapping analysed with descriptive statistics and field note taking analysed with deductive content analysis. Data were collected from April 2013 - December 2015. The units differed in the patients' levels of physical activity, the proportion of the day that patients spent with health professionals and family presence. Patients were more physically active in a unit with a combination of single and multi-bed room designs than in a unit with an entirely single-room design. Stroke units that were easy to navigate and offered variations in the physical environment had an impact on patients' activities and care. Patients' activity levels and interactions appeared to vary with the design of the physical environments of stroke units. Stroke guidelines focused on health status assessments, avoidance of bed-rest and early rehabilitation require a supportive physical environment. © 2018 The Authors. Journal of Advanced Nursing Published by John Wiley & Sons Ltd.

Evaluation of a web-based family medicine case library for self-directed learning in a third-year clerkship.

PubMed

Morrow, Jay B; Sepdham, Dan; Snell, Laura; Lindeman, Carolyn; Dobbie, Alison

2010-01-01

Web-based cases are well accepted by medical students and enable faculty to deliver equivalent educational experiences to all students. A 2009 literature search revealed no study investigating student use patterns of Web-based case libraries for self-directed learning. We investigated third-year students' use of a Web-based case program for self-directed learning in a family medicine clerkship. We analyzed Design A Case usage patterns of 210 medical students during academic year 2008--2009. We compared board score differences between these students and those from the previous 5 years who did not use Design A Case. We analyzed data from a 13-item survey, administered to a subgroup of 85 students, about the strengths, weaknesses, and acceptability of the program. Students completed, on average, four cases, which was beyond the requirement of three. They reported that the content was highly relevant to cases they saw in clinic. Almost 75% preferred the self-directed Web-based learning over didactics, and most (64%) felt they learned more electronically. Use of the cases was associated with equivalent Board scores versus didactic lectures. In our setting, self-directed learning using a Web-based case program was highly acceptable to students. Web-based cases may provide an option for family medicine educators who wish to deliver equivalent educational experiences across sites.

Evaluating the social and economic impact of community-based prenatal care.

PubMed

Cramer, Mary E; Chen, Li-Wu; Roberts, Sara; Clute, Dorothea

2007-01-01

This article describes the evaluation and findings of a community-based prenatal care program, Omaha Healthy Start (OHS), designed to reduce local racial disparities in birth outcomes. This evaluative study used a comparative descriptive design, and Targeting Outcomes of Programs was the conceptual framework for evaluation. The evaluation followed 3 groups for 2 years: OHS birth mothers (N=79; N=157); non-OHS participant birth mothers (N=746; N=774); and Douglas County birth mothers (N=7,962; N=7,987). OHS provided case management, home visits, screening, referral, transportation, and health education to participants. Program outcome measures included low birth weight, infant mortality, adequacy of care, trimester of care, and costs of care. OHS birth outcomes improved during year 2, and there was a 31% cost saving in the average hospital expenditure compared with the nonparticipant groups. Preliminary evaluative analysis indicates that prenatal case management and community outreach can improve birth outcomes for minority women, while producing cost savings. Further prospective study is needed to document trends over a longer period of time regarding the relationship between community-based case management programs for minority populations, birth outcomes, and costs of care.

A Multi-Year Program Developing an Explicit Reflective Pedagogy for Teaching Pre-service Teachers the Nature of Science by Ostention

NASA Astrophysics Data System (ADS)

Smith, Mike U.; Scharmann, Lawrence

2008-02-01

This investigation delineates a multi-year action research agenda designed to develop an instructional model for teaching the nature of science (NOS) to preservice science teachers. Our past research strongly supports the use of explicit reflective instructional methods, which includes Thomas Kuhn’s notion of learning by ostention and treating science as a continuum (i.e., comparing fields of study to one another for relative placement as less to more scientific). Instruction based on conceptual change precepts, however, also exhibits promise. Thus, the investigators sought to ascertain the degree to which conceptual change took place among students (n = 15) participating in the NOS instructional model. Three case studies are presented to illustrate successful conceptual changes that took place as a result of the NOS instructional model. All three cases represent students who claim a very conservative Christian heritage and for whom evolution was not considered a legitimate scientific theory prior to participating in the NOS instructional model. All three case study individuals, along with their twelve classmates, placed evolution as most scientific when compared to intelligent design and a fictional field of study called “Umbrellaology.”

A generalized least squares regression approach for computing effect sizes in single-case research: application examples.

PubMed

Maggin, Daniel M; Swaminathan, Hariharan; Rogers, Helen J; O'Keeffe, Breda V; Sugai, George; Horner, Robert H

2011-06-01

A new method for deriving effect sizes from single-case designs is proposed. The strategy is applicable to small-sample time-series data with autoregressive errors. The method uses Generalized Least Squares (GLS) to model the autocorrelation of the data and estimate regression parameters to produce an effect size that represents the magnitude of treatment effect from baseline to treatment phases in standard deviation units. In this paper, the method is applied to two published examples using common single case designs (i.e., withdrawal and multiple-baseline). The results from these studies are described, and the method is compared to ten desirable criteria for single-case effect sizes. Based on the results of this application, we conclude with observations about the use of GLS as a support to visual analysis, provide recommendations for future research, and describe implications for practice. Copyright © 2011 Society for the Study of School Psychology. Published by Elsevier Ltd. All rights reserved.

Improvements in the efficiency of turboexpanders in cryogenic applications

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

Agahi, R.R.; Lin, M.C.; Ershaghi, B.

1996-12-31

Process designers have utilized turboexpanders in cryogenic processes because of their higher thermal efficiencies when compared with conventional refrigeration cycles. Process design and equipment performance have improved substantially through the utilization of modern technologies. Turboexpander manufacturers have also adopted Computational Fluid Dynamic Software, Computer Numerical Control Technology and Holography Techniques to further improve an already impressive turboexpander efficiency performance. In this paper, the authors explain the design process of the turboexpander utilizing modern technology. Two cases of turboexpanders processing helium (4.35{degrees}K) and hydrogen (56{degrees}K) will be presented.

Optimum Design of High-Speed Prop-Rotors

NASA Technical Reports Server (NTRS)

Chattopadhyay, Aditi; McCarthy, Thomas Robert

1993-01-01

An integrated multidisciplinary optimization procedure is developed for application to rotary wing aircraft design. The necessary disciplines such as dynamics, aerodynamics, aeroelasticity, and structures are coupled within a closed-loop optimization process. The procedure developed is applied to address two different problems. The first problem considers the optimization of a helicopter rotor blade and the second problem addresses the optimum design of a high-speed tilting proprotor. In the helicopter blade problem, the objective is to reduce the critical vibratory shear forces and moments at the blade root, without degrading rotor aerodynamic performance and aeroelastic stability. In the case of the high-speed proprotor, the goal is to maximize the propulsive efficiency in high-speed cruise without deteriorating the aeroelastic stability in cruise and the aerodynamic performance in hover. The problems studied involve multiple design objectives; therefore, the optimization problems are formulated using multiobjective design procedures. A comprehensive helicopter analysis code is used for the rotary wing aerodynamic, dynamic and aeroelastic stability analyses and an algorithm developed specifically for these purposes is used for the structural analysis. A nonlinear programming technique coupled with an approximate analysis procedure is used to perform the optimization. The optimum blade designs obtained in each case are compared to corresponding reference designs.

Risk of acute liver injury associated with use of antibiotics. Comparative cohort and nested case-control studies using two primary care databases in Europe.

PubMed

Brauer, Ruth; Douglas, Ian; Garcia Rodriguez, Luis Alberto; Downey, Gerald; Huerta, Consuelo; de Abajo, Francisco; Bate, Andrew; Feudjo Tepie, Maurille; de Groot, Mark C H; Schlienger, Raymond; Reynolds, Robert; Smeeth, Liam; Klungel, Olaf; Ruigómez, Ana

2016-03-01

To assess the impact of varying study designs, exposure and outcome definitions on the risk of acute liver injury (ALI) associated with antibiotic use. The source population comprised of patients registered in two primary care databases, in the UK and in Spain. We identified a cohort consisting of new users of antibiotics during the study period (2004-2009) and non-users during the study period or in the previous year. Cases with ALI were identified within this cohort and classified as definite or probable, based on recorded medical information. The relative risk (RR) of ALI associated with antibiotic use was computed using Poisson regression. For the nested case-control analyses, up to five controls were matched to each case by age, sex, date and practice (in CPRD) and odds ratios (OR) were computed with conditional logistic regression. The age, sex and year adjusted RRs of definite ALI in the current antibiotic use periods was 10.04 (95% CI: 6.97-14.47) in CPRD and 5.76 (95% CI: 3.46-9.59) in BIFAP. In the case-control analyses adjusting for life-style, comorbidities and use of medications, the OR of ALI for current users of antibiotics was and 5.7 (95% CI: 3.46-9.36) in CPRD and 2.6 (95% CI: 1.26-5.37) in BIFAP. Guided by a common protocol, both cohort and case-control study designs found an increased risk of ALI associated with the use of antibiotics in both databases, independent of the exposure and case definitions used. However, the magnitude of the risk was higher in CPRD compared to BIFAP. Copyright © 2016 John Wiley & Sons, Ltd.

Case Management in Primary Care for Frequent Users of Health Care Services: A Mixed Methods Study.

PubMed

Hudon, Catherine; Chouinard, Maud-Christine; Dubois, Marie-France; Roberge, Pasquale; Loignon, Christine; Tchouaket, Éric; Lambert, Mireille; Hudon, Émilie; Diadiou, Fatoumata; Bouliane, Danielle

2018-05-01

This study aimed to evaluate the effects of the V1SAGES case management intervention (Vulnerable Patients in Primary Care: Nurse Case Management and Self-management Support) for frequent users of health care services with chronic disease and complex care needs on psychological distress and patient activation. We used a 2-phase sequential mixed methods design. The first phase was a pragmatic randomized controlled trial with intention-to-treat analysis that measured the effects of the intervention compared with usual care on psychological distress and patient activation before and after 6 months. The second phase had a qualitative descriptive design and entailed thematic analysis of in-depth interviews (25 patients, 6 case management nurses, 9 health managers) and focus groups (8 patients' spouses, 21 family physicians) to understand stakeholders' perceived effects of the intervention on patients. A total of 247 patients were randomized into the intervention group (n = 126) or the control group (n = 121). Compared with usual care, the intervention reduced psychological distress (odds ratio = 0.43; 95% CI, 0.19-0.95, P = .04), but did not have any significant effect on patient activation ( P = .43). Qualitative results suggested that patients and their spouses benefitted from the case management intervention, gaining a sense of security, and stakeholders noted better patient self-management of health. Together, our study's quantitative and qualitative results suggest that case management reduces psychological distress, making patients and caregivers feel more secure, whereas impact on self-management is unclear. Case management is a promising avenue to improve outcomes among frequent users of health care with complex needs. © 2018 Annals of Family Medicine, Inc.

Personalizing and Contextualizing Multimedia Case Methods in University-based Teacher Education: An Important Modification for Promoting Technological Design in School Science

NASA Astrophysics Data System (ADS)

Bencze, Larry; Hewitt, Jim; Pedretti, Erminia

2009-01-01

Results of various studies suggest that multimedia ‘case methods’ (activities associated with case documentaries) have many benefits in university-based teacher education contexts. They can, for example, help to ‘bridge the gap’ between perspectives and practices held by academic teacher educators and those held by student-teachers - who may adhere to perspectives and practices commonly supported in schools. On the other hand, some studies, along with theoretical arguments, suggest that there are limits to the effectiveness of multimedia case methods - because, for example, they can never fully represent realities of teaching and learning in schools. Furthermore, often missing from multimedia case methods is the student-teacher in the role of teacher. To address these concerns, we modified an existing multimedia case method by associating it with a special practice teaching situation in a school context. Qualitative data analyzed using constant comparative methods suggest that student-teachers engaged in this modified multimedia case method developed relatively deep commitments to encouraging students to conduct technology design projects - a non-traditional practice in school science. Factors that appeared to influence development of this motivation included student-teachers’ pre-instructional perspectives about science and the personalization and contextualization inherent to the modified multimedia case method.

Promotion of Self-directed Learning Using Virtual Patient Cases

PubMed Central

Schonder, Kristine; McGee, James

2013-01-01

Objective. To assess the effectiveness of virtual patient cases to promote self-directed learning (SDL) in a required advanced therapeutics course. Design. Virtual patient software based on a branched-narrative decision-making model was used to create complex patient case simulations to replace lecture-based instruction. Within each simulation, students used SDL principles to learn course objectives, apply their knowledge through clinical recommendations, and assess their progress through patient outcomes and faculty feedback linked to their individual decisions. Group discussions followed each virtual patient case to provide further interpretation, clarification, and clinical perspective. Assessments. Students found the simulated patient cases to be organized (90%), enjoyable (82%), intellectually challenging (97%), and valuable to their understanding of course content (91%). Students further indicated that completion of the virtual patient cases prior to class permitted better use of class time (78%) and promoted SDL (84%). When assessment questions regarding material on postoperative nausea and vomiting were compared, no difference in scores were found between the students who attended the lecture on the material in 2011 (control group) and those who completed the virtual patient case on the material in 2012 (intervention group). Conclusion. Completion of virtual patient cases, designed to replace lectures and promote SDL, was overwhelmingly supported by students and proved to be as effective as traditional teaching methods. PMID:24052654

Comparative analysis of numerical models of pipe handling equipment used in offshore drilling applications

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

Pawlus, Witold, E-mail: witold.p.pawlus@ieee.org; Ebbesen, Morten K.; Hansen, Michael R.

Design of offshore drilling equipment is a task that involves not only analysis of strict machine specifications and safety requirements but also consideration of changeable weather conditions and harsh environment. These challenges call for a multidisciplinary approach and make the design process complex. Various modeling software products are currently available to aid design engineers in their effort to test and redesign equipment before it is manufactured. However, given the number of available modeling tools and methods, the choice of the proper modeling methodology becomes not obvious and – in some cases – troublesome. Therefore, we present a comparative analysis ofmore » two popular approaches used in modeling and simulation of mechanical systems: multibody and analytical modeling. A gripper arm of the offshore vertical pipe handling machine is selected as a case study for which both models are created. In contrast to some other works, the current paper shows verification of both systems by benchmarking their simulation results against each other. Such criteria as modeling effort and results accuracy are evaluated to assess which modeling strategy is the most suitable given its eventual application.« less

Optimal knockout strategies in genome-scale metabolic networks using particle swarm optimization.

PubMed

Nair, Govind; Jungreuthmayer, Christian; Zanghellini, Jürgen

2017-02-01

Knockout strategies, particularly the concept of constrained minimal cut sets (cMCSs), are an important part of the arsenal of tools used in manipulating metabolic networks. Given a specific design, cMCSs can be calculated even in genome-scale networks. We would however like to find not only the optimal intervention strategy for a given design but the best possible design too. Our solution (PSOMCS) is to use particle swarm optimization (PSO) along with the direct calculation of cMCSs from the stoichiometric matrix to obtain optimal designs satisfying multiple objectives. To illustrate the working of PSOMCS, we apply it to a toy network. Next we show its superiority by comparing its performance against other comparable methods on a medium sized E. coli core metabolic network. PSOMCS not only finds solutions comparable to previously published results but also it is orders of magnitude faster. Finally, we use PSOMCS to predict knockouts satisfying multiple objectives in a genome-scale metabolic model of E. coli and compare it with OptKnock and RobustKnock. PSOMCS finds competitive knockout strategies and designs compared to other current methods and is in some cases significantly faster. It can be used in identifying knockouts which will force optimal desired behaviors in large and genome scale metabolic networks. It will be even more useful as larger metabolic models of industrially relevant organisms become available.

A Comparison of Math Cover, Copy, Compare Intervention Procedures for Children with Autism Spectrum Disorder.

PubMed

Morton, Reeva C; Gadke, Daniel L

2018-03-01

Cover, Copy, Compare (CCC) and Copy, Cover, Compare (MCCC) procedures are effective interventions for improving math fluency. However, there is a gap in literature exploring the use of these interventions for children with autism spectrum disorders (ASD). The purpose of the current study was to compare the use of CCC and MCCC for children with ASD using a multi-component single-case experimental design. The results showed no notable difference between the interventions. Implications and limitations, particularly surrounding experimental control, are discussed in detail.

Comparing Dutch case management care models for people with dementia and their caregivers: The design of the COMPAS study.

PubMed

MacNeil Vroomen, Janet; Van Mierlo, Lisa D; van de Ven, Peter M; Bosmans, Judith E; van den Dungen, Pim; Meiland, Franka J M; Dröes, Rose-Marie; Moll van Charante, Eric P; van der Horst, Henriëtte E; de Rooij, Sophia E; van Hout, Hein P J

2012-05-28

Dementia care in the Netherlands is shifting from fragmented, ad hoc care to more coordinated and personalised care. Case management contributes to this shift. The linkage model and a combination of intensive case management and joint agency care models were selected based on their emerging prominence in the Netherlands. It is unclear if these different forms of case management are more effective than usual care in improving or preserving the functioning and well-being at the patient and caregiver level and at the societal cost. The objective of this article is to describe the design of a study comparing these two case management care models against usual care. Clinical and cost outcomes are investigated while care processes and the facilitators and barriers for implementation of these models are considered. Mixed methods include a prospective, observational, controlled, cohort study among persons with dementia and their primary informal caregiver in regions of the Netherlands with and without case management including a qualitative process evaluation. Inclusion criteria for the cohort study are: community-dwelling individuals with a dementia diagnosis who are not terminally-ill or anticipate admission to a nursing home within 6 months and with an informal caregiver who speaks fluent Dutch. Person with dementia-informal caregiver dyads are followed for two years. The primary outcome measure is the Neuropsychiatric Inventory for the people with dementia and the General Health Questionnaire for their caregivers. Secondary outcomes include: quality of life and needs assessment in both persons with dementia and caregivers, activity of daily living, competence of care, and number of crises. Costs are measured from a societal perspective using cost diaries. Process indicators measure the quality of care from the participant's perspective. The qualitative study uses purposive sampling methods to ensure a wide variation of respondents. Semi-structured interviews with stakeholders based on the theoretical model of adaptive implementation are planned. This study provides relevant insights into care processes, description of two case management models along with clinical and economic data from persons with dementia and caregivers to clarify important differences in two case management care models compared to usual care.

Development of techniques for evaluating the physiological protective efficiency of civil aviation oxygen equipment.

DOT National Transportation Integrated Search

1967-04-01

A number of techniques for determining the protective efficiency of passenger and crew masks was developed, utilized and compared. In the case of newly developed passenger masks, subjects were exposed to a chamber flight profile designed around the N...

Bayesian Optimal Interval Design: A Simple and Well-Performing Design for Phase I Oncology Trials.

PubMed

Yuan, Ying; Hess, Kenneth R; Hilsenbeck, Susan G; Gilbert, Mark R

2016-09-01

Despite more than two decades of publications that offer more innovative model-based designs, the classical 3 + 3 design remains the most dominant phase I trial design in practice. In this article, we introduce a new trial design, the Bayesian optimal interval (BOIN) design. The BOIN design is easy to implement in a way similar to the 3 + 3 design, but is more flexible for choosing the target toxicity rate and cohort size and yields a substantially better performance that is comparable with that of more complex model-based designs. The BOIN design contains the 3 + 3 design and the accelerated titration design as special cases, thus linking it to established phase I approaches. A numerical study shows that the BOIN design generally outperforms the 3 + 3 design and the modified toxicity probability interval (mTPI) design. The BOIN design is more likely than the 3 + 3 design to correctly select the MTD and allocate more patients to the MTD. Compared with the mTPI design, the BOIN design has a substantially lower risk of overdosing patients and generally a higher probability of correctly selecting the MTD. User-friendly software is freely available to facilitate the application of the BOIN design. Clin Cancer Res; 22(17); 4291-301. ©2016 AACR. ©2016 American Association for Cancer Research.

Impact of Flipped Classroom Design on Student Performance and Perceptions in a Pharmacotherapy Course

PubMed Central

Koo, Cathy L.; Demps, Elaine L.; Bowman, John D.; Panahi, Ladan; Boyle, Paul

2016-01-01

Objective. To determine whether a flipped classroom design would improve student performance and perceptions of the learning experience compared to traditional lecture course design in a required pharmacotherapy course for second-year pharmacy students. Design. Students viewed short online videos about the foundational concepts and answered self-assessment questions prior to face-to-face sessions involving patient case discussions. Assessment. Pretest/posttest and precourse/postcourse surveys evaluated students’ short-term knowledge retention and perceptions before and after the redesigned course. The final grades improved after the redesign. Mean scores on the posttest improved from the pretest. Postcourse survey showed 88% of students were satisfied with the redesign. Students reported that they appreciated the flexibility of video viewing and knowledge application during case discussions but some also struggled with time requirements of the course. Conclusion. The redesigned course improved student test performance and perceptions of the learning experience during the first year of implementation. PMID:27073286

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.

[The case-case-time-control study design].

PubMed

Wang, Jing; Zhuo, Lin; Zhan, Siyan

2014-12-01

Although the 'self-matched case-only studies' (such as the case-cross-over or self-controlled case-series method) can control the time-invariant confounders (measured or unmeasured) through design of the study, however, they can not control those confounders that vary with time. A bidirectional case-crossover design can be used to adjust the exposure-time trends. In the areas of pharmaco-epidemiology, illness often influence the future use of medications, making a bidirectional study design problematic. Suissa's case-time-control design combines the case-crossover and the case-control design which could adjust for exposure-trend bias, but the control group may reintroduce selection bias, if the matching does not go well. We propose a "case-case-time-control" design which is an extension of the case-time-control design. However, rather than using a sample of external controls, we choose those future cases as controls for current cases to counter the bias that arising from temporal trends caused by exposure to the target of interest. In the end of this article we will discuss the strength and limitations of this design based on an applied example.

DEVELOPMENT OF A METHOD TO DESIGN A LOW-CARBON SOCIETY IN SMALL COMMUNITY AND ITS APPLICATION TO PUTRAJAYA, MALAYSIA

NASA Astrophysics Data System (ADS)

Hayashi, Yuri; Simson, Janice. J.; Gomi, Kei; Matsuoka, Yuzuru

In this study, we developed the method to design Low-carbon society for small communities almost without industry, with regarding of costs for countermeasures. Then we applied it to Putrajaya, Malaysia, and estimate Socio-economic indicators, energy demand, CO2 emission in year 2007 and 2025. For countermeasure case in 2025, we set three cases according to their priority; Transport, Renewable energy, Building, and calculated costs for countermeasures also. As a result, it was shown that it is possible to reduce 45% of CO2 emission by 2025 compared to 2007 level. Renewable energy priority case needs the highest cost, and Building and Transport was estimated to be the second and third highest. C-ExSS will help more realistic discussion on the policy and countermeasures for developing low-carbon society based on their costs.

Implementation of Building Information Modeling (BIM) in Construction: A Comparative Case Study

NASA Astrophysics Data System (ADS)

Rowlinson, Steve; Collins, Ronan; Tuuli, Martin M.; Jia, Yunyan

2010-05-01

Building Information Modeling (BIM) approach is increasingly adopted in coordination of construction projects, with a number of parties providing BIM services and software solutions. However, the empirical impact of BIM on construction industry has yet to be investigated. This paper explores the interaction between BIM and the construction industry during its implementation, with a specific focus on the empirical impacts of BIM on the design and construction processes and professional roles during the process. Two cases were selected from recent construction projects coordinated with BIM systems: the Venetian Casino project in Macau and the Cathy Pacific Cargo Terminal project in Hong Kong. The former case illustrates how the conflicts emerged during the design process and procurement were addressed by adopting a BIM approach. The latter demonstrates how the adoption of BIM altered the roles of architect, contractor, and sub-contractors involved in the project. The impacts of BIM were critically reviewed and discussed.

Pitting and Bending Fatigue Evaluations of a New Case-Carburized Gear Steel

NASA Technical Reports Server (NTRS)

Krantz, Timothy; Tufts, Brian

2007-01-01

The power density of a gearbox is an important consideration for many applications and is especially important for gearboxes used on aircraft. One approach to improving power density of gearing is to improve the steel properties by design of the alloy. The alloy tested in this work was designed to be case-carburized with surface hardness of Rockwell C66 after hardening. Test gear performance was evaluated using surface fatigue tests and single-tooth bending fatigue tests. The performance of gears made from the new alloy was compared to the performance of gears made from two alloys currently used for aviation gearing. The new alloy exhibited significantly better performance in surface fatigue testing, demonstrating the value of the improved properties in the case layer. However, the alloy exhibited lesser performance in single-tooth bending fatigue testing. The fracture toughness of the tested gears was insufficient for use in aircraft applications as judged by the behavior exhibited during the single tooth bending tests. This study quantified the performance of the new alloy and has provided guidance for the design and development of next generation gear steels.

Association between the 2008-09 seasonal influenza vaccine and pandemic H1N1 illness during Spring-Summer 2009: four observational studies from Canada.

PubMed

Skowronski, Danuta M; De Serres, Gaston; Crowcroft, Natasha S; Janjua, Naveed Z; Boulianne, Nicole; Hottes, Travis S; Rosella, Laura C; Dickinson, James A; Gilca, Rodica; Sethi, Pam; Ouhoummane, Najwa; Willison, Donald J; Rouleau, Isabelle; Petric, Martin; Fonseca, Kevin; Drews, Steven J; Rebbapragada, Anuradha; Charest, Hugues; Hamelin, Marie-Eve; Boivin, Guy; Gardy, Jennifer L; Li, Yan; Kwindt, Trijntje L; Patrick, David M; Brunham, Robert C

2010-04-06

In late spring 2009, concern was raised in Canada that prior vaccination with the 2008-09 trivalent inactivated influenza vaccine (TIV) was associated with increased risk of pandemic influenza A (H1N1) (pH1N1) illness. Several epidemiologic investigations were conducted through the summer to assess this putative association. (1) test-negative case-control design based on Canada's sentinel vaccine effectiveness monitoring system in British Columbia, Alberta, Ontario, and Quebec; (2) conventional case-control design using population controls in Quebec; (3) test-negative case-control design in Ontario; and (4) prospective household transmission (cohort) study in Quebec. Logistic regression was used to estimate odds ratios for TIV effect on community- or hospital-based laboratory-confirmed seasonal or pH1N1 influenza cases compared to controls with restriction, stratification, and adjustment for covariates including combinations of age, sex, comorbidity, timeliness of medical visit, prior physician visits, and/or health care worker (HCW) status. For the prospective study risk ratios were computed. Based on the sentinel study of 672 cases and 857 controls, 2008-09 TIV was associated with statistically significant protection against seasonal influenza (odds ratio 0.44, 95% CI 0.33-0.59). In contrast, estimates from the sentinel and three other observational studies, involving a total of 1,226 laboratory-confirmed pH1N1 cases and 1,505 controls, indicated that prior receipt of 2008-09 TIV was associated with increased risk of medically attended pH1N1 illness during the spring-summer 2009, with estimated risk or odds ratios ranging from 1.4 to 2.5. Risk of pH1N1 hospitalization was not further increased among vaccinated people when comparing hospitalized to community cases. Prior receipt of 2008-09 TIV was associated with increased risk of medically attended pH1N1 illness during the spring-summer 2009 in Canada. The occurrence of bias (selection, information) or confounding cannot be ruled out. Further experimental and epidemiological assessment is warranted. Possible biological mechanisms and immunoepidemiologic implications are considered.

Creating advantages through franchising in healthcare: a qualitative, multiple embedded case study on the role of the business format.

PubMed

Nijmeijer, Karlijn J; Huijsman, Robbert; Fabbricotti, Isabelle N

2014-11-02

Business format franchising is an organizational form that originates from the business sector. It is increasingly used in healthcare, being a promising organizational form for improving the competitiveness and efficiency of organizations, the quality of care, and the professional work environment. However, evidence is lacking concerning how these healthcare franchises should be designed to actually deliver the promised benefits. This study explores how the design of the central element in franchising, the business format (i.e., brand name, support systems, specification of the products and services), helps or hinders the achievement of positive results. A qualitative comparative embedded case study was conducted. The cases focused on three Dutch healthcare franchises providing mental healthcare, hospital care and care for the intellectually disabled. The data were collected through document analyses, observations, and 96 in-depth, semi-structured interviews with franchisors and unit actors (franchisees, unit managers, professionals). The interviews were recorded and transcribed verbatim. A conceptual model based on a systematic review of studies in other industries was used as an initial method for coding the data. New inductive codes were used to enrich and extend the analysis. The data were subjected to within-case and cross-case comparative thematic analyses. Different business format designs have different effects on results, as perceived by franchisors and unit actors. The analysis revealed how this variation in perceived effects can be explained by different dynamics with regard to system-wide adaptation, local adaptation, professionals' resistance to change, ease of knowledge sharing, bureaucracy, overhead, uniform brand presentation, accelerating effects and reliable performance levels. The analysis resulted in a new typology of four types of business formats, showing how combinations of business format elements facilitate or hinder the achievement of different types of results. Practitioners using healthcare franchising as a model to improve client-related, strategic, organizational and professional results should carefully consider how to design their business format in order to facilitate the achievement of desired results. The developed typology can be used as a starting point for these practitioners and as a basis for future scholarly research. Further quantitative research is recommended to confirm the results.

The role of private industry in pragmatic comparative effectiveness trials.

PubMed

Buesching, Don P; Luce, Bryan R; Berger, Marc L

2012-03-01

Comparative effectiveness research (CER) includes pragmatic clinical trials (PCTs) to address 'real-world' effectiveness. CER interest would be expected to stimulate biopharmaceutical manufacturer PCT investment; however, this does not seem to be the case. In this article we identify all industry-sponsored PCT studies from 1996 to 2010; analyze them across a variety of characteristics, including sponsor, research question, design, comparators and results; and suggest methodological and policy changes to spur future manufacturer PCT investment. Nine 'naturalistic', head-to-head versus standard of care or similar agent PCTs were identified. Two included a 'usual care' arm. Chronic care trials' length averaged 12 months (range: 6-24 months), six of which reported equivocal or no difference in effectiveness; results of two chronic and the single acute care PCTs favored the sponsor drug. None reported the sponsor drug inferior. Of seven that evaluated utilization or costs, six reported no differences and four of five studies comparing brand-generic drugs reported no difference. Whereas private investment in PCTs is in the public interest, manufacturers apparently have not yet seen the business case. To induce investment, we propose several methodological and regulatory policy innovations designed to reduce business risk by decreasing outcome variability and increasing trial efficiency, flexibility and market applicability.

Design of combinatorial libraries for the exploration of virtual hits from fragment space searches with LoFT.

PubMed

Lessel, Uta; Wellenzohn, Bernd; Fischer, J Robert; Rarey, Matthias

2012-02-27

A case study is presented illustrating the design of a focused CDK2 library. The scaffold of the library was detected by a feature trees search in a fragment space based on reactions from combinatorial chemistry. For the design the software LoFT (Library optimizer using Feature Trees) was used. The special feature called FTMatch was applied to restrict the parts of the queries where the reagents are permitted to match. This way a 3D scoring function could be simulated. Results were compared with alternative designs by GOLD docking and ROCS 3D alignments.

Design of inside cut von koch fractal UWB MIMO antenna

NASA Astrophysics Data System (ADS)

Tharani, V.; Shanmuga Priya, N.; Rajesh, A.

2017-11-01

An Inside Cut Hexagonal Von Koch fractal MIMO antenna is designed for UWB applications and its characteristics behaviour are studied. Self-comparative and space filling properties of Koch fractal structure are utilized in the antenna design which leads to the desired miniaturization and wideband characteristics. The hexagonal shaped Von Koch Fractal antenna with Defected Ground Structure (DGS) is designed on FR4 substrate with a compact size of 30mm x 20mm x 1.6mm. The antenna achieves a maximum of -44dB and -51dB at 7.1GHz for 1-element and 2-element case respectively.

Quantifying driver's field-of-view in tractors: methodology and case study.

PubMed

Gilad, Issachar; Byran, Eyal

2015-01-01

When driving a car, the visual awareness is important for operating and controlling the vehicle. When operating a tractor, it is even more complex. This is because the driving is always accompanied with another task (e.g., plough) that demands constant changes of body postures, to achieve the needed Field-of-View (FoV). Therefore, the cockpit must be well designed to provide best FoV. Today, the driver's FoV is analyzed mostly by computer simulations of a cockpit model and a Digital Human Model (DHM) positioned inside. The outcome is an 'Eye view' that displays what the DHM 'sees'. This paper suggests a new approach that adds quantitative information to the current display; presented on three tractor models as case studies. Based on the results, the design can be modified. This may assist the engineer, to analyze, compare and improve the design, for better addressing the driver needs.

Neurocognitive performance in family-based and case-control studies of schizophrenia.

PubMed

Gur, Ruben C; Braff, David L; Calkins, Monica E; Dobie, Dorcas J; Freedman, Robert; Green, Michael F; Greenwood, Tiffany A; Lazzeroni, Laura C; Light, Gregory A; Nuechterlein, Keith H; Olincy, Ann; Radant, Allen D; Seidman, Larry J; Siever, Larry J; Silverman, Jeremy M; Sprock, Joyce; Stone, William S; Sugar, Catherine A; Swerdlow, Neal R; Tsuang, Debby W; Tsuang, Ming T; Turetsky, Bruce I; Gur, Raquel E

2015-04-01

Neurocognitive deficits in schizophrenia (SZ) are established and the Consortium on the Genetics of Schizophrenia (COGS) investigated such measures as endophenotypes in family-based (COGS-1) and case-control (COGS-2) studies. By requiring family participation, family-based sampling may result in samples that vary demographically and perform better on neurocognitive measures. The Penn computerized neurocognitive battery (CNB) evaluates accuracy and speed of performance for several domains and was administered across sites in COGS-1 and COGS-2. Most tests were included in both studies. COGS-1 included 328 patients with SZ and 497 healthy comparison subjects (HCS) and COGS-2 included 1195 patients and 1009 HCS. Demographically, COGS-1 participants were younger, more educated, with more educated parents and higher estimated IQ compared to COGS-2 participants. After controlling for demographics, the two samples produced very similar performance profiles compared to their respective controls. As expected, performance was better and with smaller effect sizes compared to controls in COGS-1 relative to COGS-2. Better performance was most pronounced for spatial processing while emotion identification had large effect sizes for both accuracy and speed in both samples. Performance was positively correlated with functioning and negatively with negative and positive symptoms in both samples, but correlations were attenuated in COGS-2, especially with positive symptoms. Patients ascertained through family-based design have more favorable demographics and better performance on some neurocognitive domains. Thus, studies that use case-control ascertainment may tap into populations with more severe forms of illness that are exposed to less favorable factors compared to those ascertained with family-based designs.

SuperJet International case study: a business network start-up in the aeronautics industry

NASA Astrophysics Data System (ADS)

Corallo, Angelo; de Maggio, Marco; Storelli, Davide

This chapter presents the SuperJet International case study, a start-up in the aeronautics industry characterized by a process-oriented approach and a complex and as yet evolving network of partnerships and collaborations. The chapter aims to describe the key points of the start-up process, highlighting common factors and differences compared to the TEKNE Methodology of Change, with particular reference to the second and third phase, namely, the design and deployment of new techno-organizational systems. The SuperJet International startup is presented as a case study where strategic and organizational aspects have been jointly conceived from a network-driven perspective. The chapter compares some of the guidelines of the TEKNE Methodology of Change with experiences and actual practices deriving from interviews with key players in SJI's start-up process.

Bayesian analysis of time-series data under case-crossover designs: posterior equivalence and inference.

PubMed

Li, Shi; Mukherjee, Bhramar; Batterman, Stuart; Ghosh, Malay

2013-12-01

Case-crossover designs are widely used to study short-term exposure effects on the risk of acute adverse health events. While the frequentist literature on this topic is vast, there is no Bayesian work in this general area. The contribution of this paper is twofold. First, the paper establishes Bayesian equivalence results that require characterization of the set of priors under which the posterior distributions of the risk ratio parameters based on a case-crossover and time-series analysis are identical. Second, the paper studies inferential issues under case-crossover designs in a Bayesian framework. Traditionally, a conditional logistic regression is used for inference on risk-ratio parameters in case-crossover studies. We consider instead a more general full likelihood-based approach which makes less restrictive assumptions on the risk functions. Formulation of a full likelihood leads to growth in the number of parameters proportional to the sample size. We propose a semi-parametric Bayesian approach using a Dirichlet process prior to handle the random nuisance parameters that appear in a full likelihood formulation. We carry out a simulation study to compare the Bayesian methods based on full and conditional likelihood with the standard frequentist approaches for case-crossover and time-series analysis. The proposed methods are illustrated through the Detroit Asthma Morbidity, Air Quality and Traffic study, which examines the association between acute asthma risk and ambient air pollutant concentrations. © 2013, The International Biometric Society.

Is the large simple trial design used for comparative, post-approval safety research? A review of a clinical trials registry and the published literature.

PubMed

Reynolds, Robert F; Lem, Joanna A; Gatto, Nicolle M; Eng, Sybil M

2011-10-01

Post-approval, observational drug safety studies face well known difficulties in controlling for confounding, particularly confounding by indication for drug use. A study design that addresses confounding by indication is the large simple trial (LST). LSTs are characterized by large sample sizes, often in the thousands; broad entry criteria consistent with the approved medication label; randomization based on equipoise, i.e. neither physician nor patient believes that one treatment option is superior; minimal, streamlined data collection requirements; objectively-measured endpoints (e.g. death, hospitalization); and follow-up that minimizes interventions or interference with normal clinical practice. In theory then, the LST is a preferred study design for drug and vaccine safety research because it controls for biases inherent to observational research while still providing results that are generalizable to 'real-world' use. To evaluate whether LSTs are used for comparative safety evaluation and if the design is, in fact, advantageous compared with other designs, we conducted a review of the published literature (1949 through 31 December 2010) and the ClinicalTrials.gov registry (2000 through 31 December 2010). Thirteen ongoing or completed safety LSTs were identified. The design has rarely been used in comparative drug safety research, which is due to the operational, financial and scientific hurdles of implementing the design. The studies that have been completed addressed important clinical questions and, in some cases, led to re-evaluation of medical practice. We conclude the design has demonstrated utility for comparative safety research of medicines and vaccines if the necessary scientific and operational conditions for its use are met.

The Effectiveness of the Italian Seismic Code NT08 Prescriptions in Reproducing the Observed Site Amplification: the City of Rome and the Acquasanta Terme Town, Italy, Case Study

NASA Astrophysics Data System (ADS)

Caserta, A.; Doumaz, F.; Pischiutta, M.; Costanzo, A.

2017-12-01

In the European design code EU08 used in Italy as NT08, site effects are accounted through several scaling factors, depending on the Vs30 and topographic conditions. The effectiveness of such approach has been tested in two case studies. The first one is located in the Tiber valley, the main sedimentary basin of the city of Rome. The second one is located in Acquasanta Terme town (central Appennines). In both cases, the expected amplification levels according to the Italian design code, was calculated on the basis of the velocity profile and other geological information collected in-situ. The expected values were compared in the former case (Rome) with data recorded during the seismic sequence following the 2009 April 6th, Mw=6.3 L'Aquila earthquake (mainshock, and aftershocks) and in the latter case (Acquasanta Terme) with moderate-magnitude aftershocks following the 2016 August 24th, Mw = 6.0, Amatrice missed main shock. Our results highlight that the parameterizations adopted by the design code are not sufficient to reproduce the real ground shaking occurring during earthquakes. These means that the Vs30 parameter ignores three-dimensional and frequency-dependent effects, as well as the influence of the near surface geology deeper than 30 meters.

The 1992-1993 advanced design program. Part 1: The Mars methane engine project. Part 2: The Mars oxygen processor new furnace

NASA Astrophysics Data System (ADS)

Lauer, Stephen; Hoover, Scott; Lawrence, Lori; Paparistodemou, Christos; Taylor, Doug

1993-04-01

Three constituents of the Martian atmosphere, methane, carbon dioxide, and oxygen, can be used for internal combustion in engines utilized for future space exploration on Mars. These three gases, considered as the test case in this research, will be examined to determine required flow rates needed for combustion and optimization of engine performance. Results of the test case are examined in relation to a base case of methane and air for comparative purposes. Testing of exhaust temperatures, cylinder pressure, and exhaust gas analysis were performed for the base case and test case. Also described is a study utilizing a zirconia cell to convert carbon dioxide into usable oxygen to help support future Mars missions.

The 1992-1993 advanced design program. Part 1: The Mars methane engine project. Part 2: The Mars oxygen processor new furnace

NASA Technical Reports Server (NTRS)

Lauer, Stephen; Hoover, Scott; Lawrence, Lori; Paparistodemou, Christos; Taylor, Doug

1993-01-01

Three constituents of the Martian atmosphere, methane, carbon dioxide, and oxygen, can be used for internal combustion in engines utilized for future space exploration on Mars. These three gases, considered as the test case in this research, will be examined to determine required flow rates needed for combustion and optimization of engine performance. Results of the test case are examined in relation to a base case of methane and air for comparative purposes. Testing of exhaust temperatures, cylinder pressure, and exhaust gas analysis were performed for the base case and test case. Also described is a study utilizing a zirconia cell to convert carbon dioxide into usable oxygen to help support future Mars missions.

Modeling Multibody Stage Separation Dynamics Using Constraint Force Equation Methodology

NASA Technical Reports Server (NTRS)

Tartabini, Paul V.; Roithmayr, Carlos M.; Toniolo, Matthew D.; Karlgaard, Christopher D.; Pamadi, Bandu N.

2011-01-01

This paper discusses the application of the constraint force equation methodology and its implementation for multibody separation problems using three specially designed test cases. The first test case involves two rigid bodies connected by a fixed joint, the second case involves two rigid bodies connected with a universal joint, and the third test case is that of Mach 7 separation of the X-43A vehicle. For the first two cases, the solutions obtained using the constraint force equation method compare well with those obtained using industry- standard benchmark codes. For the X-43A case, the constraint force equation solutions show reasonable agreement with the flight-test data. Use of the constraint force equation method facilitates the analysis of stage separation in end-to-end simulations of launch vehicle trajectories

School Effectiveness in the Dominican Republic.

ERIC Educational Resources Information Center

British Columbia Univ., Vancouver. Faculty of Education.

Characteristics distinguishing more effective from less effective public primary (grades 1 to 8) schools in Santo Domingo were studied, using a comparative case study design. The effectiveness of the school was determined by expert nomination and achievement tests in reading, mathematics, and writing. Socioeconomic status was controlled and three…

Refined ambient PM2.5 exposure surrogates and the risk of myocardial infarction

EPA Science Inventory

Using a case-crossover study design and conditional logistic regression, we compared the relative odds of transmural (full-wall) myocardial infarction (MI) calculated using exposure surrogates that account for human activity patterns and the indoor transport of ambient PM_2....

Organisational Learning through International M&A Integration Strategies

ERIC Educational Resources Information Center

Holland, Wayne; Salama, Alzira

2010-01-01

Purpose: The purpose of this research paper is to explore the learning process associated with international mergers and acquisitions (M&A) integration strategies. Design/methodology/approach: The paper employs a comparative case study methodology, utilising qualitative data through in-depth interviews with top management responsible for…

Aerodynamic design and analysis of small horizontal axis wind turbine blades

NASA Astrophysics Data System (ADS)

Tang, Xinzi

This work investigates the aerodynamic design and analysis of small horizontal axis wind turbine blades via the blade element momentum (BEM) based approach and the computational fluid dynamics (CFD) based approach. From this research, it is possible to draw a series of detailed guidelines on small wind turbine blade design and analysis. The research also provides a platform for further comprehensive study using these two approaches. The wake induction corrections and stall corrections of the BEM method were examined through a case study of the NREL/NASA Phase VI wind turbine. A hybrid stall correction model was proposed to analyse wind turbine power performance. The proposed model shows improvement in power prediction for the validation case, compared with the existing stall correction models. The effects of the key rotor parameters of a small wind turbine as well as the blade chord and twist angle distributions on power performance were investigated through two typical wind turbines, i.e. a fixed-pitch variable-speed (FPVS) wind turbine and a fixed-pitch fixed-speed (FPFS) wind turbine. An engineering blade design and analysis code was developed in MATLAB to accommodate aerodynamic design and analysis of the blades.. The linearisation for radial profiles of blade chord and twist angle for the FPFS wind turbine blade design was discussed. Results show that, the proposed linearisation approach leads to reduced manufacturing cost and higher annual energy production (AEP), with minimal effects on the low wind speed performance. Comparative studies of mesh and turbulence models in 2D and 3D CFD modelling were conducted. The CFD predicted lift and drag coefficients of the airfoil S809 were compared with wind tunnel test data and the 3D CFD modelling method of the NREL/NASA Phase VI wind turbine were validated against measurements. Airfoil aerodynamic characterisation and wind turbine power performance as well as 3D flow details were studied. The detailed flow characteristics from the CFD modelling are quantitatively comparable to the measurements, such as blade surface pressure distribution and integrated forces and moments. It is confirmed that the CFD approach is able to provide a more detailed qualitative and quantitative analysis for wind turbine airfoils and rotors..

Design and analysis of multiple diseases genome-wide association studies without controls.

PubMed

Chen, Zhongxue; Huang, Hanwen; Ng, Hon Keung Tony

2012-11-15

In genome-wide association studies (GWAS), multiple diseases with shared controls is one of the case-control study designs. If data obtained from these studies are appropriately analyzed, this design can have several advantages such as improving statistical power in detecting associations and reducing the time and cost in the data collection process. In this paper, we propose a study design for GWAS which involves multiple diseases but without controls. We also propose corresponding statistical data analysis strategy for GWAS with multiple diseases but no controls. Through a simulation study, we show that the statistical association test with the proposed study design is more powerful than the test with single disease sharing common controls, and it has comparable power to the overall test based on the whole dataset including the controls. We also apply the proposed method to a real GWAS dataset to illustrate the methodologies and the advantages of the proposed design. Some possible limitations of this study design and testing method and their solutions are also discussed. Our findings indicate that the proposed study design and statistical analysis strategy could be more efficient than the usual case-control GWAS as well as those with shared controls. Copyright © 2012 Elsevier B.V. All rights reserved.

The Effect of Air Preheat at Atmospheric Pressure on the Formation of NO(x) in the Quick-Mix Sections of an Axially Staged Combustor

NASA Technical Reports Server (NTRS)

Vardakas, M. A.; Leong, M. Y.; Brouwer, J.; Samuelsen, G. S.; Holdeman, J. D.

1999-01-01

The Rich-burn/Quick-mix/Lean-burn (RQL) combustor concept has been proposed to minimize the formation of nitrogen oxides (NO(x)) in gas turbine systems. The success of this combustor strategy is dependent upon the efficiency of the mixing section bridging the fuel-rich and fuel-lean stages. Note that although these results were obtained from an experiment designed to study an RQL mixer, the link between mixing and NOx signatures is considerably broader than this application, in that the need to understand this link exists in most advanced combustors. The experiment reported herein was designed to study the effects of inlet air temperature on NO(x) formation in a mixing section. The results indicate that NO(x) emission is increased for all preheated cases compared to non-preheated cases. When comparing the various mixing modules, the affect of jet penetration is important, as this determines where NO(x) concentrations peak, and affects overall NO(x) production. Although jet air comprises 70 percent of the total airflow, the impact that jet air preheat has on overall NO(x) emissions is small compared to preheating both main and jet air flow.

Repair of Composites: Design Choices Leading to Lower Life-Cycle Cost

NASA Astrophysics Data System (ADS)

Kassapoglou, Christos; Rangelov, Konstantin; Rangelov, Svilen

2017-08-01

The fabrication cost of composite aircraft structures is revisited and the effect of part size on cost is examined with emphasis on design decisions which affect the ease of (bonded) repair and the total cost of the part and subsequent repairs. The case of moderately loaded stiffened fuselage or wing panels under compression is analysed in detail and the fabrication cost of the panel made as a single piece or as an assembly of smaller identical components or modules is determined. The cost of special purpose repairs for two different damage sizes is compared to removing and replacing damaged modules. Hand layup and automated processing are compared. It is found that for certain repair sizes removing and replacing modules leads to lower overall cost as compared to applying a special purpose repair.

Application of composite materials to impact-insensitive munitions

NASA Technical Reports Server (NTRS)

Neradka, Vincent F.; Chang, Yale; Grady, Joseph E.; Trowbridge, Daniel A.

1992-01-01

An approach is outlined for developing bullet-impact-insensitive munitions based on composite materials that provide rapid venting of the rocket-motor case. Impact experiments are conducted with test specimens of hybrid laminates of graphite/epoxy and epoxy reinforcing with woven glass fibers. The dynamic strain response and initial impact force are measured with strain gauges, and perforation damage is examined in the plates. The results show that impact damage can be designed by means of parametric variations of the fiber, matrix, and ply orientations. It is suggested that rocket-motor cases can be designed with composite materials to provide rapid venting during the failure mode. The experimental ballistic testing performed provides data that can be used comparatively with analytical data on composite materials.

A comparison of estimators from self-controlled case series, case-crossover design, and sequence symmetry analysis for pharmacoepidemiological studies.

PubMed

Takeuchi, Yoshinori; Shinozaki, Tomohiro; Matsuyama, Yutaka

2018-01-08

Despite the frequent use of self-controlled methods in pharmacoepidemiological studies, the factors that may bias the estimates from these methods have not been adequately compared in real-world settings. Here, we comparatively examined the impact of a time-varying confounder and its interactions with time-invariant confounders, time trends in exposures and events, restrictions, and misspecification of risk period durations on the estimators from three self-controlled methods. This study analyzed self-controlled case series (SCCS), case-crossover (CCO) design, and sequence symmetry analysis (SSA) using simulated and actual electronic medical records datasets. We evaluated the performance of the three self-controlled methods in simulated cohorts for the following scenarios: 1) time-invariant confounding with interactions between the confounders, 2) time-invariant and time-varying confounding without interactions, 3) time-invariant and time-varying confounding with interactions among the confounders, 4) time trends in exposures and events, 5) restricted follow-up time based on event occurrence, and 6) patient restriction based on event history. The sensitivity of the estimators to misspecified risk period durations was also evaluated. As a case study, we applied these methods to evaluate the risk of macrolides on liver injury using electronic medical records. In the simulation analysis, time-varying confounding produced bias in the SCCS and CCO design estimates, which aggravated in the presence of interactions between the time-invariant and time-varying confounders. The SCCS estimates were biased by time trends in both exposures and events. Erroneously short risk periods introduced bias to the CCO design estimate, whereas erroneously long risk periods introduced bias to the estimates of all three methods. Restricting the follow-up time led to severe bias in the SSA estimates. The SCCS estimates were sensitive to patient restriction. The case study showed that although macrolide use was significantly associated with increased liver injury occurrence in all methods, the value of the estimates varied. The estimations of the three self-controlled methods depended on various underlying assumptions, and the violation of these assumptions may cause non-negligible bias in the resulting estimates. Pharmacoepidemiologists should select the appropriate self-controlled method based on how well the relevant key assumptions are satisfied with respect to the available data.

A comparative case study of the characteristics of science, technology, engineering, and mathematics (STEM) focused high schools

NASA Astrophysics Data System (ADS)

Scott, Catherine Elizabeth

This study examined the characteristics of 10 science, technology, engineering, and mathematics (STEM) focused high schools. A comparative case designed was used to identify key components of STEM school designs. Schools were selected from various regions across the United States. Data collected included websites, national statistics database, standardized test scores, interviews and published articles. Results from this study indicate that there is a variety of STEM high school programs designed to increase students' ability to pursue college degrees in STEM fields. The school mission statements influence the overall school design. Students at STEM schools must submit an application to be admitted to STEM high schools. Half of the STEM high schools used a lottery system to select students. STEM high schools have a higher population of black students and a lower population of white and Hispanic students than most schools in the United States. They serve about the same number of economically disadvantaged students. The academic programs at STEM high schools are more rigorous with electives focused on STEM content. In addition to coursework requirements, students must also complete internships and/or a capstone project. Teachers who teach in STEM schools are provided regularly scheduled professional development activities that focus on STEM content and pedagogy. Teachers provide leadership in the development and delivery of the professional development activities.

Augmented design and analysis of computer experiments: a novel tolerance embedded global optimization approach applied to SWIR hyperspectral illumination design.

PubMed

Keresztes, Janos C; John Koshel, R; D'huys, Karlien; De Ketelaere, Bart; Audenaert, Jan; Goos, Peter; Saeys, Wouter

2016-12-26

A novel meta-heuristic approach for minimizing nonlinear constrained problems is proposed, which offers tolerance information during the search for the global optimum. The method is based on the concept of design and analysis of computer experiments combined with a novel two phase design augmentation (DACEDA), which models the entire merit space using a Gaussian process, with iteratively increased resolution around the optimum. The algorithm is introduced through a series of cases studies with increasing complexity for optimizing uniformity of a short-wave infrared (SWIR) hyperspectral imaging (HSI) illumination system (IS). The method is first demonstrated for a two-dimensional problem consisting of the positioning of analytical isotropic point sources. The method is further applied to two-dimensional (2D) and five-dimensional (5D) SWIR HSI IS versions using close- and far-field measured source models applied within the non-sequential ray-tracing software FRED, including inherent stochastic noise. The proposed method is compared to other heuristic approaches such as simplex and simulated annealing (SA). It is shown that DACEDA converges towards a minimum with 1 % improvement compared to simplex and SA, and more importantly requiring only half the number of simulations. Finally, a concurrent tolerance analysis is done within DACEDA for to the five-dimensional case such that further simulations are not required.

Snippets From the Past: Is Flint, Michigan, the Birthplace of the Case-Control Study?

PubMed Central

Morabia, Alfredo

2013-01-01

In the summer of 1924, an outbreak of scarlet fever occurred in Flint, Michigan. Unable to trace it to the usual causes, particularly fresh milk, the Michigan Department of Health used a novel approach to disentangle the enigma: The 116 cases of scarlet fever were compared with 117 “controls” selected from neighbors of the quarantined cases and from patients at the City Health Center who had been treated for ailments unrelated to scarlet fever. The extraordinary culprit was ice cream, which had a frequent/occasional/none consumption prevalence of 60%, 34%, and 6% among the cases and 24%, 51%, and 25% among the controls, respectively. The 1925 report reads, “Detailed epidemiological investigation, by means of case histories and control histories on well persons, confirmed early suspicions and established the fact that the epidemic was spread by ice cream” (Am J Hyg. 1925;5(5):669–681). This forgotten epidemiologic study is the oldest study using the case-control design to have been resurrected thus far. The case-control study design may have been conceived simultaneously, but independently and for different purposes, in England (Janet Lane-Claypon's 1926 report on the determinants of breast cancer) and the United States. PMID:24064743

Efficient critical design load case identification for floating offshore wind turbines with a reduced nonlinear model

NASA Astrophysics Data System (ADS)

Matha, Denis; Sandner, Frank; Schlipf, David

2014-12-01

Design verification of wind turbines is performed by simulation of design load cases (DLC) defined in the IEC 61400-1 and -3 standards or equivalent guidelines. Due to the resulting large number of necessary load simulations, here a method is presented to reduce the computational effort for DLC simulations significantly by introducing a reduced nonlinear model and simplified hydro- and aerodynamics. The advantage of the formulation is that the nonlinear ODE system only contains basic mathematic operations and no iterations or internal loops which makes it very computationally efficient. Global turbine extreme and fatigue loads such as rotor thrust, tower base bending moment and mooring line tension, as well as platform motions are outputs of the model. They can be used to identify critical and less critical load situations to be then analysed with a higher fidelity tool and so speed up the design process. Results from these reduced model DLC simulations are presented and compared to higher fidelity models. Results in frequency and time domain as well as extreme and fatigue load predictions demonstrate that good agreement between the reduced and advanced model is achieved, allowing to efficiently exclude less critical DLC simulations, and to identify the most critical subset of cases for a given design. Additionally, the model is applicable for brute force optimization of floater control system parameters.

Rare variant association analysis in case-parents studies by allowing for missing parental genotypes.

PubMed

Li, Yumei; Xiang, Yang; Xu, Chao; Shen, Hui; Deng, Hongwen

2018-01-15

The development of next-generation sequencing technologies has facilitated the identification of rare variants. Family-based design is commonly used to effectively control for population admixture and substructure, which is more prominent for rare variants. Case-parents studies, as typical strategies in family-based design, are widely used in rare variant-disease association analysis. Current methods in case-parents studies are based on complete case-parents data; however, parental genotypes may be missing in case-parents trios, and removing these data may lead to a loss in statistical power. The present study focuses on testing for rare variant-disease association in case-parents study by allowing for missing parental genotypes. In this report, we extended the collapsing method for rare variant association analysis in case-parents studies to allow for missing parental genotypes, and investigated the performance of two methods by using the difference of genotypes between affected offspring and their corresponding "complements" in case-parent trios and TDT framework. Using simulations, we showed that, compared with the methods just only using complete case-parents data, the proposed strategy allowing for missing parental genotypes, or even adding unrelated affected individuals, can greatly improve the statistical power and meanwhile is not affected by population stratification. We conclude that adding case-parents data with missing parental genotypes to complete case-parents data set can greatly improve the power of our strategy for rare variant-disease association.

Computation-based virtual screening for designing novel antimalarial drugs by targeting falcipain-III: a structure-based drug designing approach.

PubMed

Kesharwani, Rajesh Kumar; Singh, Durg Vijay; Misra, Krishna

2013-01-01

Cysteine proteases (falcipains), a papain-family of enzymes of Plasmodium falciparum, are responsible for haemoglobin degradation and thus necessary for its survival during asexual life cycle phase inside the human red blood cells while remaining non-functional for the human body. Therefore, these can act as potential targets for designing antimalarial drugs. The P. falciparum cysteine proteases, falcipain-II and falcipain- III are the enzymes which initiate the haemoglobin degradation, therefore, have been selected as targets. In the present study, we have designed new leupeptin analogues and subjected to virtual screening using Glide at the active site cavity of falcipain-II and falcipain-III to select the best docked analogues on the basis of Glide score and also compare with the result of AutoDock. The proposed analogues can be synthesized and tested in vivo as future potent antimalarial drugs. Protein falcipain-II and falcipain-III together with bounds inhibitors epoxysuccinate E64 (E64) and leupeptin respectively were retrieved from protein data bank (PDB) and latter leupeptin was used as lead molecule to design new analogues by using Ligbuilder software and refined the molecules on the basis of Lipinski rule of five and fitness score parameters. All the designed leupeptin analogues were screened via docking simulation at the active site cavity of falcipain-II and falcipain-III by using Glide software and AutoDock. The 104 new leupeptin-based antimalarial ligands were designed using structure-based drug designing approach with the help of Ligbuilder and subjected for virtual screening via docking simulation method against falcipain-II and falcipain-III receptor proteins. The Glide docking results suggest that the ligands namely result_037 shows good binding and other two, result_044 and result_042 show nearly similar binding than naturally occurring PDB bound ligand E64 against falcipain-II and in case of falcipain-III, 15 designed leupeptin analogues having better binding affinity compared to the PDB bound inhibitor of falcipain-III. The docking simulation results of falcipain-III with designed leupeptin analogues using Glide compared with AutoDock and find 80% similarity as better binder than leupeptin. These results further highlight new leupeptin analogues as promising future inhibitors for chemotherapeutic prevention of malaria. The result of Glide for falcipain-III has been compared with the result of AutoDock and finds very less differences in their order of binding affinity. Although there are no extra hydrogen bonds, however, equal number of hydrogen bonds with variable strength as compared to leupeptin along with the enhanced hydrophobic and electrostatic interactions in case of analogues supports our study that it holds the ligand molecules strongly within the receptor. The comparative e-pharmacophoric study also suggests and supports our predictions regarding the minimum features required in ligand molecule to behave as falcipain- III inhibitors and is also helpful in screening the large database as future antimalarial inhibitors.

Factors Associated with the Performance and Cost-Effectiveness of Using Lymphatic Filariasis Transmission Assessment Surveys for Monitoring Soil-Transmitted Helminths: A Case Study in Kenya

PubMed Central

Smith, Jennifer L.; Sturrock, Hugh J. W.; Assefa, Liya; Nikolay, Birgit; Njenga, Sammy M.; Kihara, Jimmy; Mwandawiro, Charles S.; Brooker, Simon J.

2015-01-01

Transmission assessment surveys (TAS) for lymphatic filariasis have been proposed as a platform to assess the impact of mass drug administration (MDA) on soil-transmitted helminths (STHs). This study used computer simulation and field data from pre- and post-MDA settings across Kenya to evaluate the performance and cost-effectiveness of the TAS design for STH assessment compared with alternative survey designs. Variations in the TAS design and different sample sizes and diagnostic methods were also evaluated. The district-level TAS design correctly classified more districts compared with standard STH designs in pre-MDA settings. Aggregating districts into larger evaluation units in a TAS design decreased performance, whereas age group sampled and sample size had minimal impact. The low diagnostic sensitivity of Kato-Katz and mini-FLOTAC methods was found to increase misclassification. We recommend using a district-level TAS among children 8–10 years of age to assess STH but suggest that key consideration is given to evaluation unit size. PMID:25487730

Comparison of mission design options for manned Mars missions

NASA Technical Reports Server (NTRS)

Babb, Gus R.; Stump, William R.

1986-01-01

A number of manned Mars mission types, propulsion systems, and operational techniques are compared. Conjunction and opposition class missions for cryogenic, hybrid (cryo/storable), and NERVA propulsion concepts are addressed. In addition, both Earth and Mars orbit aerobraking, direct entry of landers, hyperbolic rendezvous, and electric propulsion cases are examined. A common payload to Mars was used for all cases. The basic figure of merit used was weight in low Earth orbit (LEO) at mission initiation. This is roughly proportional to launch costs.

Cementless total knee arthroplasty

PubMed Central

Risitano, Salvatore; Sabatini, Luigi; Giachino, Matteo; Agati, Gabriele; Massè, Alessandro

2016-01-01

Interest for uncemented total knee arthroplasty (TKA) has greatly increased in recent years. This technique, less used than cemented knee replacement in the last decades, sees a revival thanks an advance in prosthetic design, instrumentation and operative technique. The related literature in some cases shows conflicting data on survival and on the revision’s rate, but in most cases a success rate comparable to cemented TKA is reported. The optimal fixation in TKA is a subject of debate with the majority of surgeons favouring cemented fixation. PMID:27162779

Quality assurance in surgical practice through auditing.

PubMed

Wong, W T

1980-05-01

An efficient auditing method is presented which involves objective criteria-based numerical screening of medical process and treatment outcome by paramedical staff and detailed analysis of deviated cases by surgeons. If properly performed it requires the study of no more than 50 cases in a diagnostic category to provide sufficient information about the quality of care. Encouraging points as well as problems are communicated to the surgeons to induce the maintenance or improvement of the standard of care. Graphic documentation of case performance is possible, allowing surgeons to compare results with their colleagues. The general performance level of several consecutive studies can be compared at a glance. In addition, logical education programs to improve the medical process can be designed on the basis of the problems identified. As all the cases with an unacceptable outcome are traceable to inadequate medical process, improvement in this area will decrease outcome defects. With the use of auditing and the follow-up technique described, the quality of care in surgery may be assured.

Multiple case studies of STEM teachers' orientations to science teaching through engineering design

NASA Astrophysics Data System (ADS)

Rupp, Madeline

The following master's thesis is composed of two manuscripts describing STEM teachers' orientations to science teaching through engineering within the context of the Science Learning through Engineering Design (SLED) partnership. The framework guiding both studies was science teaching orientations, a component of pedagogical content knowledge. Data were collected via semi-structured interviews, multi-day classroom observations, pre- and post-observation interviews, implementation plans, and written reflections. Data sources were analyzed to generate two orientations to science teaching through engineering design for each participant. The first manuscript illustrates a single case study conducted with a sixth grade STEM teacher. Results of this study revealed a detailed picture of the teacher's goals, practices, assessments, and general views when teaching science through engineering design. Common themes across the teacher's instruction were used to characterize her orientations to science teaching through engineering design. Overall, the teacher's orientations showed a shift in her practice from didactic to student-centered methods of teaching as a result of integrating engineering design-based curriculum. The second manuscript describes a comparative case study of two sixth grade SLED participants. Results of this study revealed more complex and diverse relationships between the teachers' orientations to teaching science through engineering design and their instruction. Participants' orientations served as filters for instruction, guided by their divergent purposes for science teaching. Furthermore, their orientations and resulting implementation were developed from knowledge gained in teacher education, implying that teacher educators and researchers can use this framework to learn more about how teachers' knowledge is used to integrate engineering and science practices in the K-12 classroom.

Design of simplified maximum-likelihood receivers for multiuser CPM systems.

PubMed

Bing, Li; Bai, Baoming

2014-01-01

A class of simplified maximum-likelihood receivers designed for continuous phase modulation based multiuser systems is proposed. The presented receiver is built upon a front end employing mismatched filters and a maximum-likelihood detector defined in a low-dimensional signal space. The performance of the proposed receivers is analyzed and compared to some existing receivers. Some schemes are designed to implement the proposed receivers and to reveal the roles of different system parameters. Analysis and numerical results show that the proposed receivers can approach the optimum multiuser receivers with significantly (even exponentially in some cases) reduced complexity and marginal performance degradation.

Economic comparison of fabric filters and electrostatic precipitators for particulate control on coal-fired utility boilers

NASA Technical Reports Server (NTRS)

Cukor, P. M.; Chapman, R. A.

1978-01-01

The uncertainties and associated costs involved in selecting and designing a particulate control device to meet California's air emission regulations are considered. The basic operating principles of electrostatic precipitators and fabric filters are discussed, and design parameters are identified. The size and resulting cost of the control device as a function of design parameters is illustrated by a case study for an 800 MW coal-fired fired utility boiler burning a typical southwestern subbituminous coal. The cost of selecting an undersized particulate control device is compared with the cost of selecting an oversized device.

A new Faraday rotator for high average power lasers

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

Khazanov, E A

2001-04-30

The new design of a Faraday rotator is proposed which allows one to compensate partially the radiation depolarisation in magneto-optical elements induced by heating due to the laser radiation absorption. The new design is compared analytically and numerically with a conventional design for the cases of glass and crystal magneto-optical media. It is shown that a rotator, which provides the compensation for birefringence in active elements with the accuracy up to 1 % at the average laser radiation power of 1 kW in the rotator, can be created. (laser applications and other topics in quantum electronics)

A Simple and Robust Method for Partially Matched Samples Using the P-Values Pooling Approach

PubMed Central

Kuan, Pei Fen; Huang, Bo

2013-01-01

This paper focuses on statistical analyses in scenarios where some samples from the matched pairs design are missing, resulting in partially matched samples. Motivated by the idea of meta-analysis, we recast the partially matched samples as coming from two experimental designs, and propose a simple yet robust approach based on the weighted Z-test to integrate the p-values computed from these two designs. We show that the proposed approach achieves better operating characteristics in simulations and a case study, compared to existing methods for partially matched samples. PMID:23417968

Effects of borehole design on complex electrical resistivity measurements: laboratory validation and numerical experiments

NASA Astrophysics Data System (ADS)

Treichel, A.; Huisman, J. A.; Zhao, Y.; Zimmermann, E.; Esser, O.; Kemna, A.; Vereecken, H.

2012-12-01

Geophysical measurements within a borehole are typically affected by the presence of the borehole. The focus of the current study is to quantify the effect of borehole design on broadband electrical impedance tomography (EIT) measurements within boreholes. Previous studies have shown that effects on the real part of the electrical resistivity are largest for boreholes with large diameters and for materials with a large formation factor. However, these studies have not considered the effect of the well casing and the filter gravel on the measurement of the real part of the electrical resistivity. In addition, the effect of borehole design on the imaginary part of the electrical resistivity has not been investigated yet. Therefore, the aim of this study is to investigate the effect of borehole design on the complex electrical resistivity using laboratory measurements and numerical simulations. In order to do so, we developed a high resolution two dimensional axisymmetric finite element model (FE) that enables us to simulate the effects of several key borehole design parameters (e.g. borehole diameter, thickness of PVC well casing) on the measurement process. For the material surrounding the borehole, realistic values for complex resistivity were obtained from a database of laboratory measurements of complex resistivity from the test site Krauthausen (Germany). The slotted PVC well casing is represented by an effective resistivity calculated from the water-filled slot volume and the PVC volume. Measurements with and without PVC well casing were made with a four-electrode EIT logging tool in a water-filled rain barrel. The initial comparison for the case that the logging tool was inserted in the PVC well casing showed a considerable mismatch between measured and modeled values. It was required to consider a complete electrode model instead of point electrodes to remove this mismatch. This validated model was used to investigate in detail how complex resistivity measurements with different electrode configurations are affected by borehole design. Finally, the plausibility of our results was verified by comparing the simulation results with borehole EIT measurements made at the test site Krauthausen.

Incidental Becomes Visible: A Comparison of School- and Community-Based Field Experience Narratives

ERIC Educational Resources Information Center

Holder, K. C.; Downey, Jayne A.

2008-01-01

The purpose of this study was to describe and compare student learning documented using written field experience summary narratives and occurring in community-based or school-based locations. Utilizing a hybrid portraiture--instrumental case study design, two researchers selected participants from undergraduate educational psychology courses using…

A comparative analysis of high-speed rail station development into destination and multi-use facilities : the case of San Jose Diridon [summary].

DOT National Transportation Integrated Search

2017-02-01

The authors reviewed the literature on planning intermodal transit facilities, extracting recommendations about station and station-area design and land uses, operation of transportation services, and policy actions for station-area planning. They al...

Management Education: An Experimental Course.

ERIC Educational Resources Information Center

Gutelius, Paul Payne

The thesis describes the design, implementation, and evaluation of a course in the theory and practice of management. It gives an appraisal of programmed learning techniques and compares three methods of teaching management--by readings, by cases, and by computer gaming. Additionally, it relates student reactions to the opportunity to select one…

Long-Term Effect of Prefrontal Lobotomy on Verbal Fluency in Patients with Schizophrenia

ERIC Educational Resources Information Center

Stip, Emmanuel; Bigras, Marie-Josee.; Mancini-Marie, Adham; Cosset, Marie-Eve.; Black, Deborah; Lecours, Andre-Roch

2004-01-01

Objective: This study investigated the long-term effects of bilateral prefrontal leukotomy on lexical abilities in schizophrenia subjects. Method: We compared performances of leukotomized (LSP), non-leukotomized schizophrenia patients (NLSP) and normal controls, using a test of verbal fluency. Multiple case and triple comparison design were…

English in China's Language Policies for Higher Education

ERIC Educational Resources Information Center

Xu, Hongmei

2012-01-01

Taking ecological language planning and policy as its conceptual orientation and interpretive policy analysis as its methodological framework, and following an embedded single-case study design, this study explores the role of English, as compared with the role of Chinese, in China's educational language planning and policy for higher education.…

Principals and Teachers "Craft Coherence" among Accountability Policies

ERIC Educational Resources Information Center

Stosich, Elizabeth Leisy

2018-01-01

Purpose: The purpose of this paper is to examine how US school leaders and teachers make sense of multiple accountability policies, including the Common Core State Standards and teacher evaluation, and how this process relates to school priorities and classroom practice. Design/methodology/approach: This study uses a comparative case study…

Biosimilars clinical development program: confirmatory clinical trials: a virtual/simulated case study comparing equivalence and non-inferiority approaches.

PubMed

Fletcher, Mark P

2011-09-01

As part of long term commitment of the Biologicals and Vaccines Committee (B&V) of the International Federation of Pharmaceutical Manufacturers and Association (IFPMA) to provide expert input to the WHO on their recently finalized GUIDELINES ON EVALUATION OF SIMILAR BIOTHERAPEUTIC PRODUCTS (SBPs), and in response to WHO's request, the IFPMA B&V prepared a clinical case study at a recent WHO workshop in Seoul, Korea. The case study, presented by Mark Fletcher on behalf of B&V, involved a model scenario for a clinical efficacy trial to support the approval of a Similar Biotherapeutic Product (SBP) as part of the required comparative clinical program against a Reference Biotherapeutic Product (RBP). A key goal was to understand and illustrate key clinical and statistical principles, and considerations described in the WHO Guidance for regulatory authorities when designing and implementing WHO guidelines and post-approval regulatory oversight for SBPs. Using this model SBP/RBP pair, an interactive discussion was carried out among the workshop participants on the pros and cons of using equivalence vs. non-inferiority designs to assess the two products' similarity. Through discussion of the case, the complexity of demonstrating similar efficacy and safety of a SBP vs. RBP for biotherapeutic products is outlined and discussed in the context of the key principles laid out in the recently published WHO GUIDELINES ON EVALUATION OF SIMILAR BIOTHERAPEUTIC PRODUCTS (SBPs). The exercise illustrates the need for a case-by-case approach when interpreting clinical data from SBP dossiers to adequately assure similar efficacy and safety of SBPs for any studied indication. Copyright © 2011. Published by Elsevier Ltd.

Eight years' experience with an IVF surrogate gestational pregnancy programme.

PubMed

Raziel, Arieh; Schachter, Morey; Strassburger, Deborah; Komarovsky, Dafna; Ron-El, Raphael; Friedler, Shevach

2005-08-01

The aim of this study was to retrospectively audit eight years' experience of an IVF surrogate gestational programme and to compare the outcome of surrogacy due to absence of the uterus with surrogacy indicated for repeated IVF failure and recurrent abortions. A total of 60 cycles of IVF surrogate pregnancy were initiated in 19 treated couples. Absence of the uterus was the indication for surrogacy in 10 cases: Rokitansky syndrome (eight cases) and post-hysterectomy (two cases) designated as group A. The indications in the remaining nine patients (group B) were: IVF implantation failure (three cases), habitual abortions (four cases) and deteriorating maternal diseases (two cases). IVF performance and subsequent pregnancy outcome of groups A and B were compared. There was no difference in ovarian stimulation parameters and in IVF performance between the groups A and B. The overall pregnancy rate per transfer was 10/60 (17%). The pregnancy rates per patient and per transfer were 7/10 (70%) and 7/35 (20%) in group A compared with 3/9 (33%) and 3/25 (12%) in group B. A median number of three treatment cycles were needed to achieve pregnancy. In conclusion, the existence or absence of the uterus in the commissioning mothers is irrelevant for their IVF performance and conception rates. In patients who conceived after more than three IVF cycles, an additional 'oocyte factor' might be present.

One-shot estimate of MRMC variance: AUC.

PubMed

Gallas, Brandon D

2006-03-01

One popular study design for estimating the area under the receiver operating characteristic curve (AUC) is the one in which a set of readers reads a set of cases: a fully crossed design in which every reader reads every case. The variability of the subsequent reader-averaged AUC has two sources: the multiple readers and the multiple cases (MRMC). In this article, we present a nonparametric estimate for the variance of the reader-averaged AUC that is unbiased and does not use resampling tools. The one-shot estimate is based on the MRMC variance derived by the mechanistic approach of Barrett et al. (2005), as well as the nonparametric variance of a single-reader AUC derived in the literature on U statistics. We investigate the bias and variance properties of the one-shot estimate through a set of Monte Carlo simulations with simulated model observers and images. The different simulation configurations vary numbers of readers and cases, amounts of image noise and internal noise, as well as how the readers are constructed. We compare the one-shot estimate to a method that uses the jackknife resampling technique with an analysis of variance model at its foundation (Dorfman et al. 1992). The name one-shot highlights that resampling is not used. The one-shot and jackknife estimators behave similarly, with the one-shot being marginally more efficient when the number of cases is small. We have derived a one-shot estimate of the MRMC variance of AUC that is based on a probabilistic foundation with limited assumptions, is unbiased, and compares favorably to an established estimate.

Design and rationale for Home Blood Pressure Telemonitoring and Case Management to Control Hypertension (HyperLink): a cluster randomized trial.

PubMed

Margolis, Karen L; Kerby, Tessa J; Asche, Stephen E; Bergdall, Anna R; Maciosek, Michael V; O'Connor, Patrick J; Sperl-Hillen, JoAnn M

2012-07-01

Patients with high blood pressure (BP) visit a physician an average of 4 times or more per year in the U.S., yet BP is controlled in fewer than half. Practical, robust and sustainable models are needed to improve BP in patients with uncontrolled hypertension. The Home Blood Pressure Telemonitoring and Case Management to Control Hypertension study (HyperLink) is a cluster-randomized trial designed to determine whether an intervention that combines home BP telemonitoring with pharmacist case management improves BP control compared to usual care at 6 and 12 months in patients with uncontrolled hypertension. Secondary outcomes are maintenance of BP control at 18 months, patient satisfaction with their health care, and costs of care. HyperLink enrolled 450 hypertensive patients with uncontrolled BP from 16 primary care clinics. Eight clinics were randomized to provide usual care (UC) to their patients (n=222) and 8 were randomized to provide the telemonitoring intervention (TI) (n=228). TI patients received home BP telemonitors that internally store and electronically transmit BP data to a secure database. Pharmacist case managers adjust antihypertensive therapy based on the home BP data under a collaborative practice agreement with the clinics' primary care teams. The length of the intervention is 12 months, with follow-up to 18 months to determine the durability of the intervention. We will test in a real primary care setting whether combining BP telemonitoring and pharmacist case management can achieve and maintain high rates of BP control compared to usual care. Copyright © 2012 Elsevier Inc. All rights reserved.

Unconditional or Conditional Logistic Regression Model for Age-Matched Case-Control Data?

PubMed

Kuo, Chia-Ling; Duan, Yinghui; Grady, James

2018-01-01

Matching on demographic variables is commonly used in case-control studies to adjust for confounding at the design stage. There is a presumption that matched data need to be analyzed by matched methods. Conditional logistic regression has become a standard for matched case-control data to tackle the sparse data problem. The sparse data problem, however, may not be a concern for loose-matching data when the matching between cases and controls is not unique, and one case can be matched to other controls without substantially changing the association. Data matched on a few demographic variables are clearly loose-matching data, and we hypothesize that unconditional logistic regression is a proper method to perform. To address the hypothesis, we compare unconditional and conditional logistic regression models by precision in estimates and hypothesis testing using simulated matched case-control data. Our results support our hypothesis; however, the unconditional model is not as robust as the conditional model to the matching distortion that the matching process not only makes cases and controls similar for matching variables but also for the exposure status. When the study design involves other complex features or the computational burden is high, matching in loose-matching data can be ignored for negligible loss in testing and estimation if the distributions of matching variables are not extremely different between cases and controls.

[Use of four kinds of three-dimensional printing guide plate in bone tumor resection and reconstruction operation].

PubMed

Fu, Jun; Guo, Zheng; Wang, Zhen; Li, Xiangdong; Fan, Hongbin; Li, Jing; Pei, Yanjun; Pei, Guoxian; Li, Dan

2014-03-01

To explore the effectiveness of excision and reconstruction of bone tumor by using operation guide plate made by variety of three-dimensional (3-D) printing techniques, and to compare the advantages and disadvantages of different 3-D printing techniques in the manufacture and application of operation guide plate. Between September 2012 and January 2014, 31 patients with bone tumor underwent excision and reconstruction of bone tumor by using operation guide plate. There were 19 males and 12 females, aged 6-67 years (median, 23 years). The disease duration ranged from 15 days to 12 months (median, 2 months). There were 13 cases of malignant tumor and 18 cases of benign tumor. The tumor located in the femur (9 cases), the spine (7 cases), the tibia (6 cases), the pelvis (5 cases), the humerus (3 cases), and the fibula (1 case). Four kinds of 3-D printing technique were used in processing operation guide plate: fused deposition modeling (FDM) in 9 cases, stereo lithography appearance (SLA) in 14 cases, 3-D printing technique in 5 cases, and selective laser sintering (SLS) in 3 cases; the materials included ABS resin, photosensitive resin, plaster, and aluminum alloy, respectively. Before operation, all patients underwent thin layer CT scanning (0.625 mm) in addition to conventional imaging. The data were collected for tumor resection design, and operation guide plate was designed on the basis of excision plan. Preoperatively, the operation guide plates were made by 3-D printing equipment. After sterilization, the guide plates were used for excision and reconstruction of bone tumor. The time of plates processing cycle was recorded to analyse the efficiency of 4 kinds of 3-D printing techniques. The time for design and operation and intraoperative fluoroscopy frequency were recorded. Twenty-eight patients underwent similar operations during the same period as the control group. The processing time of operation guide plate was (19.3 +/- 6.5) hours in FDM, (5.2 +/- 1.3) hours in SLA, (8.6 +/- 1.9) hours in 3-D printing technique, and (51.7 +/- 12.9) hours in SLS. The preoperative design and operation guide plate were successfully made, which was used for excision and reconstruction of bone tumor in 31 cases. Except 3 failures (operation guide plate fracture), the resection and reconstruction operations followed the preoperative design in the other 28 cases. The patients had longer design time, shorter operation time, and less fluoroscopy frequency than the patients of the control group, showing significant differences (P < 0.05). The follow-up time was 1-12 months (mean, 3.7 months). Postoperative X-ray and CT showed complete tumor resection and stable reconstruction. 3-D printing operation guide plates are well adapted to the requirements of individual operation for bone tumor resection and reconstruction. The 4 kinds of 3-D printing techniques have their own advantages and should be chosen according to the need of operation.

Factorial versus multi-arm multi-stage designs for clinical trials with multiple treatments.

PubMed

Jaki, Thomas; Vasileiou, Despina

2017-02-20

When several treatments are available for evaluation in a clinical trial, different design options are available. We compare multi-arm multi-stage with factorial designs, and in particular, we will consider a 2 × 2 factorial design, where groups of patients will either take treatments A, B, both or neither. We investigate the performance and characteristics of both types of designs under different scenarios and compare them using both theory and simulations. For the factorial designs, we construct appropriate test statistics to test the hypothesis of no treatment effect against the control group with overall control of the type I error. We study the effect of the choice of the allocation ratios on the critical value and sample size requirements for a target power. We also study how the possibility of an interaction between the two treatments A and B affects type I and type II errors when testing for significance of each of the treatment effects. We present both simulation results and a case study on an osteoarthritis clinical trial. We discover that in an optimal factorial design in terms of minimising the associated critical value, the corresponding allocation ratios differ substantially to those of a balanced design. We also find evidence of potentially big losses in power in factorial designs for moderate deviations from the study design assumptions and little gain compared with multi-arm multi-stage designs when the assumptions hold. © 2016 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd. © 2016 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd.

Designing for Persuasion: Toward Ambient Eco-Visualization for Awareness

NASA Astrophysics Data System (ADS)

Kim, Tanyoung; Hong, Hwajung; Magerko, Brian

When people are aware of their lifestyle's ecological consequences, they are more likely to adjust their behavior to reduce their impact. Persuasive design that provides feedback to users without interfering with their primary tasks can increases the awareness of neighboring problems. As a case study of design for persuasion, we designed two ambient displays as desktop widgets. Both represent a users' computer usage time, but in different visual styles. In this paper, we present the results of a comparative study of two ambient displays. We discuss the gradual progress of persuasion supported by the ambient displays and the differences in users' perception affected by the different visualization styles. Finally, Our empirical findings lead to a series of design implications for persuasive media.

Theoretical Basis of the Test-Negative Study Design for Assessment of Influenza Vaccine Effectiveness

PubMed Central

Sullivan, Sheena G.; Tchetgen Tchetgen, Eric J.; Cowling, Benjamin J.

2016-01-01

Influenza viruses undergo frequent antigenic changes. As a result, the viruses circulating change within and between seasons, and the composition of the influenza vaccine is updated annually. Thus, estimation of the vaccine's effectiveness is not constant across seasons. In order to provide annual estimates of the influenza vaccine's effectiveness, health departments have increasingly adopted the “test-negative design,” using enhanced data from routine surveillance systems. In this design, patients presenting to participating general practitioners with influenza-like illness are swabbed for laboratory testing; those testing positive for influenza virus are defined as cases, and those testing negative form the comparison group. Data on patients' vaccination histories and confounder profiles are also collected. Vaccine effectiveness is estimated from the odds ratio comparing the odds of testing positive for influenza among vaccinated patients and unvaccinated patients, adjusting for confounders. The test-negative design is purported to reduce bias associated with confounding by health-care-seeking behavior and misclassification of cases. In this paper, we use directed acyclic graphs to characterize potential biases in studies of influenza vaccine effectiveness using the test-negative design. We show how studies using this design can avoid or minimize bias and where bias may be introduced with particular study design variations. PMID:27587721

Sequential ensemble-based optimal design for parameter estimation: SEQUENTIAL ENSEMBLE-BASED OPTIMAL DESIGN

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

Man, Jun; Zhang, Jiangjiang; Li, Weixuan

2016-10-01

The ensemble Kalman filter (EnKF) has been widely used in parameter estimation for hydrological models. The focus of most previous studies was to develop more efficient analysis (estimation) algorithms. On the other hand, it is intuitively understandable that a well-designed sampling (data-collection) strategy should provide more informative measurements and subsequently improve the parameter estimation. In this work, a Sequential Ensemble-based Optimal Design (SEOD) method, coupled with EnKF, information theory and sequential optimal design, is proposed to improve the performance of parameter estimation. Based on the first-order and second-order statistics, different information metrics including the Shannon entropy difference (SD), degrees ofmore » freedom for signal (DFS) and relative entropy (RE) are used to design the optimal sampling strategy, respectively. The effectiveness of the proposed method is illustrated by synthetic one-dimensional and two-dimensional unsaturated flow case studies. It is shown that the designed sampling strategies can provide more accurate parameter estimation and state prediction compared with conventional sampling strategies. Optimal sampling designs based on various information metrics perform similarly in our cases. The effect of ensemble size on the optimal design is also investigated. Overall, larger ensemble size improves the parameter estimation and convergence of optimal sampling strategy. Although the proposed method is applied to unsaturated flow problems in this study, it can be equally applied in any other hydrological problems.« less

Critical Approaches to Lifelong Education

NASA Astrophysics Data System (ADS)

Preston, Rosemary

1999-11-01

This paper argues that contemporary interest in lifelong learning can be seen as an artefact of the market. It points out how the attractive vocabulary associated with personal development and empowerment often masks other economic and social purposes. Bearing in mind the social function of education, the author compares the strategies for the promotion of lifelong learning designed for those in "included social categories" with the policies designed for those in marginal and excluded positions. It concludes by challenging its own position by citing positive learner experience in each case.

Design and implementation of multichannel global active structural acoustic control for a device casing

NASA Astrophysics Data System (ADS)

Mazur, Krzysztof; Wrona, Stanislaw; Pawelczyk, Marek

2018-01-01

The paper presents the idea and discussion on implementation of multichannel global active noise control systems. As a test plant an active casing is used. It has been developed by the authors to reduce device noise directly at the source by controlling vibration of its casing. To provide global acoustic effect in the whole environment, where the device operates, it requires a number of secondary sources and sensors for each casing wall, thus making the whole active control structure complicated, i.e. with a large number of interacting channels. The paper discloses all details concerning hardware setup and efficient implementation of control algorithms for the multichannel case. A new formulation is presented to introduce the distributed version of the Switched-error Filtered-reference Least Mean Squares (FXLMS) algorithm together with adaptation rate enhancement. The convergence rate of the proposed algorithm is compared with original Multiple-error FXLMS. A number of hints followed from many years of authors' experience on microprocessor control systems design and signal processing algorithms optimization are presented. They can be used for various active control and signal processing applications, both for academic research and commercialization.

Evaluating statistical and clinical significance of intervention effects in single-case experimental designs: an SPSS method to analyze univariate data.

PubMed

Maric, Marija; de Haan, Else; Hogendoorn, Sanne M; Wolters, Lidewij H; Huizenga, Hilde M

2015-03-01

Single-case experimental designs are useful methods in clinical research practice to investigate individual client progress. Their proliferation might have been hampered by methodological challenges such as the difficulty applying existing statistical procedures. In this article, we describe a data-analytic method to analyze univariate (i.e., one symptom) single-case data using the common package SPSS. This method can help the clinical researcher to investigate whether an intervention works as compared with a baseline period or another intervention type, and to determine whether symptom improvement is clinically significant. First, we describe the statistical method in a conceptual way and show how it can be implemented in SPSS. Simulation studies were performed to determine the number of observation points required per intervention phase. Second, to illustrate this method and its implications, we present a case study of an adolescent with anxiety disorders treated with cognitive-behavioral therapy techniques in an outpatient psychotherapy clinic, whose symptoms were regularly assessed before each session. We provide a description of the data analyses and results of this case study. Finally, we discuss the advantages and shortcomings of the proposed method. Copyright © 2014. Published by Elsevier Ltd.

Case definition for progressive multifocal leukoencephalopathy following treatment with monoclonal antibodies.

PubMed

Mentzer, Dirk; Prestel, Jürgen; Adams, Ortwin; Gold, Ralf; Hartung, Hans-Peter; Hengel, Hartmut; Kieseier, Bernd C; Ludwig, Wolf-Dieter; Keller-Stanislawski, Brigitte

2012-09-01

Novel immunosuppressive/modulating therapies with monoclonal antibodies (MABs) have been associated with progressive multifocal leukoencephalopathy (PML), a potentially fatal disease of the brain caused by the JC virus. Taking the complex diagnostic testing and heterogeneous clinical presentation of PML into account, an agreed case definition for PML is a prerequisite for a thorough assessment of PML. A working group was established to develop a standardised case definition for PML which permits data comparability across clinical trials, postauthorisation safety studies and passive postmarketing surveillance. The case definition is designed to define levels of diagnostic certainty of reported PML cases following treatment with MABs. It was subsequently used to categorise retrospectively suspected PML cases from Germany reported to the Paul-Ehrlich-Institute as the responsible national competent authority. The algorithm of the case definition is based on clinical symptoms, PCR for JC virus DNA in cerebrospinal fluid, brain MRI, and brain biopsy/autopsy. The case definition was applied to 119 suspected cases of PML following treatment with MABs and is considered to be helpful for case ascertainment of suspected PML cases for various MABs covering a broad spectrum of indications. Even if the available information is not yet complete, the case definition provides a level of diagnostic certainty. The proposed case definition permits data comparability among different medicinal products and among active as well as passive surveillance settings. It may form a basis for meaningful risk analysis and communication for regulators and healthcare professionals.

Design of Composite Structures Using Knowledge-Based and Case Based Reasoning

NASA Technical Reports Server (NTRS)

Lambright, Jonathan Paul

1996-01-01

A method of using knowledge based and case based reasoning to assist designers during conceptual design tasks of composite structures was proposed. The cooperative use of heuristics, procedural knowledge, and previous similar design cases suggests a potential reduction in design cycle time and ultimately product lead time. The hypothesis of this work is that the design process of composite structures can be improved by using Case-Based Reasoning (CBR) and Knowledge-Based (KB) reasoning in the early design stages. The technique of using knowledge-based and case-based reasoning facilitates the gathering of disparate information into one location that is easily and readily available. The method suggests that the inclusion of downstream life-cycle issues into the conceptual design phase reduces potential of defective, and sub-optimal composite structures. Three industry experts were interviewed extensively. The experts provided design rules, previous design cases, and test problems. A Knowledge Based Reasoning system was developed using the CLIPS (C Language Interpretive Procedural System) environment and a Case Based Reasoning System was developed using the Design Memory Utility For Sharing Experiences (MUSE) xviii environment. A Design Characteristic State (DCS) was used to document the design specifications, constraints, and problem areas using attribute-value pair relationships. The DCS provided consistent design information between the knowledge base and case base. Results indicated that the use of knowledge based and case based reasoning provided a robust design environment for composite structures. The knowledge base provided design guidance from well defined rules and procedural knowledge. The case base provided suggestions on design and manufacturing techniques based on previous similar designs and warnings of potential problems and pitfalls. The case base complemented the knowledge base and extended the problem solving capability beyond the existence of limited well defined rules. The findings indicated that the technique is most effective when used as a design aid and not as a tool to totally automate the composites design process. Other areas of application and implications for future research are discussed.

Provision of pandemic disease information by health sciences librarians: a multisite comparative case series.

PubMed

Featherstone, Robin M; Boldt, R Gabriel; Torabi, Nazi; Konrad, Shauna-Lee

2012-04-01

The research provides an understanding of pandemic information needs and informs professional development initiatives for librarians in disaster medicine. Utilizing a multisite, comparative case series design, the researchers conducted semi-structured interviews and examined supplementary materials in the form of organizational documents, correspondence, and websites to create a complete picture of each case. The rigor of the case series was ensured through data and investigator triangulation. Interview transcripts were coded using NVivo to identify common themes and points of comparison. Comparison of the four cases revealed a distinct difference between "client-initiated" and "librarian-initiated" provision of pandemic information. Librarian-initiated projects utilized social software to "push" information, whereas client-initiated projects operated within patron-determined parameters to deliver information. Health care administrators were identified as a key audience for pandemic information, and news agencies were utilized as essential information sources. Librarians' skills at evaluating available information proved crucial for selecting best-quality evidence to support administrative decision making. Qualitative analysis resulted in increased understanding of pandemic information needs and identified best practices for disseminating information during periods of high organizational stress caused by an influx of new cases of an unknown infectious disease.

Sustainable and safe design of footwear integrating ecological footprint and risk criteria.

PubMed

Herva, Marta; Álvarez, Antonio; Roca, Enrique

2011-09-15

The ecodesign of a product implies that different potential environmental impacts of diverse nature must be taken into account considering its whole life cycle, apart from the general design criteria (i.e. technical, functional, ergonomic, aesthetic or economic). In this sense, a sustainability assessment methodology, ecological footprint (EF), and environmental risk assessment (ERA), were combined for the first time to derive complementary criteria for the ecodesign of footwear. Four models of children's shoes were analyzed and compared. The synthetic shoes obtained a smaller EF (6.5 gm(2)) when compared to the leather shoes (11.1 gm(2)). However, high concentrations of hazardous substances were detected in the former, even making the Hazard Quotient (HQ) and the Cancer Risk (CR) exceed the recommended safety limits for one of the synthetic models analyzed. Risk criteria were prioritized in this case and, consequently, the design proposal was discarded. For the other cases, the perspective provided by the indicators of different nature was balanced to accomplish a fairest evaluation. The selection of fibers produced under sustainable criteria and the reduction of the materials consumption was recommended, since the area requirements would be minimized and the absence of hazardous compounds would ensure safety conditions during the use stage. Copyright © 2011 Elsevier B.V. All rights reserved.

Friction Stir Weld Restart+Reweld Repair Allowables

NASA Technical Reports Server (NTRS)

Clifton, Andrew

2008-01-01

A friction stir weld (FSW) repair method has been developed and successfully implemented on Al 2195 plate material for the Space Shuttle External Fuel Tank (ET). The method includes restarting the friction stir weld in the termination hole of the original weld followed by two reweld passes. Room temperature and cryogenic temperature mechanical properties exceeded minimum FSW design strength and compared well with the development data. Simulated service test results also compared closely to historical data for initial FSW, confirming no change to the critical flaw size or inspection requirements for the repaired weld. Testing of VPPA fusion/FSW intersection weld specimens exhibited acceptable strength and exceeded the minimum design value. Porosity, when present at the intersection was on the root side toe of the fusion weld, the "worst case" being 0.7 inch long. While such porosity may be removed by sanding, this "worst case" porosity condition was tested "as is" and demonstrated that porosity did not negatively affect the strength of the intersection weld. Large, 15-inch "wide panels" FSW repair welds were tested to demonstrate strength and evaluate residual stresses using photo stress analysis. All results exceeded design minimums, and photo stress analysis showed no significant stress gradients due to the presence of the restart and multi-pass FSW repair weld.

Central nervous system decompression sickness and venous gas emboli in hypobaric conditions.

PubMed

Balldin, Ulf I; Pilmanis, Andrew A; Webb, James T

2004-11-01

Altitude decompression sickness (DCS) that involves the central nervous system (CNS) is a rare but potentially serious condition. Identification of early symptoms and signs of this condition might improve treatment. We studied data from 26 protocols carried out in our laboratory over the period 1983-2003; all were designed to provoke DCS in a substantial proportion of subjects. The data set included 2843 cases. We classified subject-exposures that resulted in DCS as: 1) neurological DCS of peripheral and/or central origin (NEURO); 2) a subset of those that involved only the CNS (CNS); and 3) all other cases, i.e., DCS cases that did not have a neurological component (OTHER). For each case, echo imaging data were used to document whether venous gas emboli (VGE) were present, and their level was classified as: 1) any level, i.e., Grade 1 or higher (VGE-1); and 2) high level, Grade 4 (VGE-4). There were 1108 cases of altitude DCS in the database; 218 were classified as NEURO and 49 of those as CNS. VGE-1 were recorded in 83.8% of OTHER compared with 58.7% of NEURO and 55.1% of CNS (both p < 0.001 compared with OTHER). The corresponding values for VGE-4 were 48.8%, 37.0%, and 34.7% (p < 0.001, compared to OTHER). Hyperbaric oxygen (HBO) was used to treat about half of the CNS cases, while all other cases were treated with 2 h breathing 100% oxygen at ground level. Since only about half of the rare cases of hypobaric CNS DCS cases were accompanied by any level of VGE, echo imaging for bubbles may have limited application for use as a predictor of such cases.

Developing integrated clinical reasoning competencies in dental students using scaffolded case-based learning - empirical evidence.

PubMed

Postma, T C; White, J G

2016-08-01

This study provides empirical evidence of the development of integrated clinical reasoning in the discipline-based School of Dentistry, University of Pretoria, South Africa. Students were exposed to case-based learning in comprehensive patient care (CPC) in the preclinical year of study, scaffolded by means of the four-component instructional design model for complex learning. Progress test scores of third- to fifth-year dental students, who received case-based teaching and learning in the third year (2009-2011), were compared to the scores of preceding fourth- and fifth-year cohorts. These fourth- and fifth-year cohorts received content-based teaching concurrently with their clinical training in CPC. The progress test consisted of a complex case study and 32 MCQs on tracer conditions. Students had to gather the necessary information and had to make diagnostic and treatment-planning decisions. Preclinical students who participated in the case-based teaching and learning achieved similar scores compared to final-year students who received lecture-based teaching and learning. Final-year students who participated in the case-based learning made three more correct clinical decisions per student, compared to those who received content-based teaching. Students struggled more with treatment-planning than with diagnostic decisions. The scaffolded case-based learning appears to contribute to accurate clinical decisions when compared to lecture-based teaching. It is suggested that the development of integrated reasoning competencies starts as early as possible in a dental curriculum, perhaps even in the preclinical year of study. Treatment-planning should receive particular attention. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Technical assistance for law-enforcement communications: Case study report two

NASA Technical Reports Server (NTRS)

Reilly, N. B.; Mustain, J. A.

1979-01-01

Two case histories are presented. In one study the feasibility of consolidating dispatch center operations for small agencies is considered. System load measurements were taken and queueing analysis applied to determine numbers of personnel required for each separate agency and for a consolidated dispatch center. Functional requirements were developed and a cost model was designed to compare relative costs of various alternatives including continuation of the present system, consolidation of a manual system, and consolidated computer-aided dispatching. The second case history deals with the consideration of a multi-regional, intrastate radio frequency for improved interregional communications. Sample standards and specifications for radio equipment are provided.

Capsule physics comparison of National Ignition Facility implosion designs using plastic, high density carbon, and beryllium ablators

NASA Astrophysics Data System (ADS)

Clark, D. S.; Kritcher, A. L.; Yi, S. A.; Zylstra, A. B.; Haan, S. W.; Weber, C. R.

2018-03-01

Indirect drive implosion experiments on the National Ignition Facility (NIF) [E. I. Moses et al., Phys. Plasmas 16, 041006 (2009)] have now tested three different ablator materials: glow discharge polymer plastic, high density carbon, and beryllium. How do these different ablators compare in current and proposed implosion experiments on NIF? What are the relative advantages and disadvantages of each? This paper compares these different ablator options in capsule-only simulations of current NIF experiments and potential future designs. The simulations compare the impact of the capsule fill tube, support tent, and interface surface roughness for each case, as well as all perturbations in combination. According to the simulations, each ablator is impacted by the various perturbation sources differently, and each material poses unique challenges in the pursuit of ignition on NIF.

Neurocognitive performance in family-based and case-control studies of schizophrenia

PubMed Central

Gur, Ruben C.; Braff, David L.; Calkins, Monica E.; Dobie, Dorcas J.; Freedman, Robert; Green, Michael F.; Greenwood, Tiffany A.; Lazzeroni, Laura C.; Light, Gregory A.; Nuechterlein, Keith H.; Olincy, Ann; Radant, Allen D.; Seidman, Larry J.; Siever, Larry J.; Silverman, Jeremy M.; Sprock, Joyce; Stone, William S.; Sugar, Catherine A.; Swerdlow, Neal R.; Tsuang, Debby W.; Tsuang, Ming T.; Turetsky, Bruce I.; Gur, Raquel E.

2014-01-01

Background Neurocognitive deficits in schizophrenia (SZ) are established and the Consortium on the Genetics of Schizophrenia (COGS) investigated such measures as endophenotypes in family-based (COGS-1) and case-control (COGS-2) studies. By requiring family participation, family-based sampling may result in samples that vary demographically and perform better on neurocognitive measures. Methods The Penn computerized neurocognitive battery (CNB) evaluates accuracy and speed of performance for several domains and was administered across sites in COGS-1 and COGS-2. Most tests were included in both studies. COGS-1 included 328 patients with SZ and 497 healthy comparison subjects (HCS) and COGS-2 included 1195 patients and 1009 HCS. Results Demographically, COGS-1 participants were younger, more educated, with more educated parents and higher estimated IQ compared to COGS-2 participants. After controlling for demographics, the two samples produced very similar performance profiles compared to their respective controls. As expected, performance was better and with smaller effect sizes compared to controls in COGS-1 relative to COGS-2. Better performance was most pronounced for spatial processing while emotion identification had large effect sizes for both accuracy and speed in both samples. Performance was positively correlated with functioning and negatively with negative and positive symptoms in both samples, but correlations were attenuated in COGS-2, especially with positive symptoms. Conclusions Patients ascertained through family-based design have more favorable demographics and better performance on some neurocognitive domains. Thus, studies that use case-control ascertainment may tap into populations with more severe forms of illness that are exposed to less favorable factors compared to those ascertained with family-based designs. PMID:25432636

Chronic Fatigue Syndrome versus Systemic Exertion Intolerance Disease

PubMed Central

Jason, Leonard A.; Sunnquist, Madison; Brown, Abigail; Newton, Julia L.; Strand, Elin Bolle; Vernon, Suzanne D.

2015-01-01

Background The Institute of Medicine has recommended a change in the name and criteria for Chronic Fatigue Syndrome (CFS), renaming the illness Systemic Exertion Intolerance Disease (SEID). The new SEID case definition requires substantial reductions or impairments in the ability to engage in pre-illness activities, unrefreshing sleep, post-exertional malaise, and either cognitive impairment or orthostatic intolerance. Purpose In the current study, samples were generated through several different methods and were used to compare this new case definition to previous case definitions for CFS, Myalgic Encephalomyelitis (ME-ICC), Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS), as well as a case definition developed through empirical methods. Methods We used a cross-sectional design with samples from tertiary care settings, a biobank sample, and other forums. 796 patients from the US, Great Britain, and Norway completed the DePaul Symptom Questionnaire. Results Findings indicated that the SEID criteria identified 88% of participants in the samples analyzed, which is comparable to the 92% that met the Fukuda criteria. The SEID case definition was compared to a four item empiric criteria, and findings indicated that the four item empiric criteria identified a smaller, more functionally limited and symptomatic group of patients. Conclusion The recently developed SEID criteria appears to identify a group comparable in size to the Fukuda et al. criteria, but a larger group of patients than the Canadian ME/CFS and ME criteria, and selects more patients who have less impairment and fewer symptoms than a four item empiric criteria. PMID:26345409

Nurse case-manager vs multifaceted intervention to improve quality of osteoporosis care after wrist fracture: randomized controlled pilot study.

PubMed

Majumdar, S R; Johnson, J A; Bellerose, D; McAlister, F A; Russell, A S; Hanley, D A; Garg, S; Lier, D A; Maksymowych, W P; Morrish, D W; Rowe, B H

2011-01-01

Few outpatients with fractures are treated for osteoporosis in the years following fracture. In a randomized pilot study, we found a nurse case-manager could double rates of osteoporosis testing and treatment compared with a proven efficacious quality improvement strategy directed at patients and physicians (57% vs 28% rates of appropriate care). Few patients with fractures are treated for osteoporosis. An intervention directed at wrist fracture patients (education) and physicians (guidelines, reminders) tripled osteoporosis treatment rates compared to controls (22% vs 7% within 6 months of fracture). More effective strategies are needed. We undertook a pilot study that compared a nurse case-manager to the multifaceted intervention using a randomized trial design. The case-manager counseled patients, arranged bone mineral density (BMD) tests, and prescribed treatments. We included controls from our first trial who remained untreated for osteoporosis 1-year post-fracture. Primary outcome was bisphosphonate treatment and secondary outcomes were BMD testing, appropriate care (BMD test-treatment if bone mass low), and costs. Forty six patients untreated 1-year after wrist fracture were randomized to case-manager (n = 21) or multifaceted intervention (n = 25). Median age was 60 years and 68% were female. Six months post-randomization, 9 (43%) case-managed patients were treated with bisphosphonates compared with 3 (12%) multifaceted intervention patients (relative risk [RR] 3.6, 95% confidence intervals [CI] 1.1-11.5, p = 0.019). Case-managed patients were more likely than multifaceted intervention patients to undergo BMD tests (81% vs 52%, RR 1.6, 95%CI 1.1-2.4, p = 0.042) and receive appropriate care (57% vs 28%, RR 2.0, 95%CI 1.0-4.2, p = 0.048). Case-management cost was $44 (CDN) per patient vs $12 for the multifaceted intervention. A nurse case-manager substantially increased rates of appropriate testing and treatment for osteoporosis in patients at high-risk of future fracture when compared with a multifaceted quality improvement intervention aimed at patients and physicians. Even with case-management, nearly half of patients did not receive appropriate care. clinicaltrials.gov identifier: NCT00152321.

Variability in case-mix adjusted in-hospital cardiac arrest rates.

PubMed

Merchant, Raina M; Yang, Lin; Becker, Lance B; Berg, Robert A; Nadkarni, Vinay; Nichol, Graham; Carr, Brendan G; Mitra, Nandita; Bradley, Steven M; Abella, Benjamin S; Groeneveld, Peter W

2012-02-01

It is unknown how in-hospital cardiac arrest (IHCA) rates vary across hospitals and predictors of variability. Measure variability in IHCA across hospitals and determine if hospital-level factors predict differences in case-mix adjusted event rates. Get with the Guidelines Resuscitation (GWTG-R) (n=433 hospitals) was used to identify IHCA events between 2003 and 2007. The American Hospital Association survey, Medicare, and US Census were used to obtain detailed information about GWTG-R hospitals. Adult patients with IHCA. Case-mix-adjusted predicted IHCA rates were calculated for each hospital and variability across hospitals was compared. A regression model was used to predict case-mix adjusted event rates using hospital measures of volume, nurse-to-bed ratio, percent intensive care unit beds, palliative care services, urban designation, volume of black patients, income, trauma designation, academic designation, cardiac surgery capability, and a patient risk score. We evaluated 103,117 adult IHCAs at 433 US hospitals. The case-mix adjusted IHCA event rate was highly variable across hospitals, median 1/1000 bed days (interquartile range: 0.7 to 1.3 events/1000 bed days). In a multivariable regression model, case-mix adjusted IHCA event rates were highest in urban hospitals [rate ratio (RR), 1.1; 95% confidence interval (CI), 1.0-1.3; P=0.03] and hospitals with higher proportions of black patients (RR, 1.2; 95% CI, 1.0-1.3; P=0.01) and lower in larger hospitals (RR, 0.54; 95% CI, 0.45-0.66; P<0.0001). Case-mix adjusted IHCA event rates varied considerably across hospitals. Several hospital factors associated with higher IHCA event rates were consistent with factors often linked with lower hospital quality of care.

Clinical and Epidemiologic Description of Orofacial Clefts in Bogota and Cali, Colombia, 2001-2015.

PubMed

Sarmiento, K; Valencia, S; Gracia, G; Hurtado-Villa, P; Zarante, I

2018-04-01

Among congenital craniofacial anomalies, orofacial clefts (OFCs) are the most common. Global prevalence is 2 in 1000 and in Colombia, 1 in 700. Our goal was to describe cleft palate (CP) prevalence and cleft lip with or without cleft palate (CL±P) from 2001 to 2015 in Bogota and Cali, Colombia. Using the ECLAMC case-control design method, information was obtained from the Congenital Anomalies Monitoring and Surveillance Programs in Bogota and Cali. We describe the prevalence of cases classified into the following groups: isolated, polymalformed, and syndromic. The proportion of cases and controls was 1:4. Data were analyzed using frequency distribution and Student t test to compare means and 95% confidence intervals (CIs). We identified 529 OFC cases and 2116 controls from 448,930 births: a rate of 11.8 per 10,000 (CI = 10.80-12.83). From the total cases, 73% were identified with CL/CP compared to 27% with CP. Males had higher CL±P (59%) prevalence, whereas the highest neonatal mortality was observed among polymalformed cases (7%). The most common anomaly identified among our cases was cleft lip without isolated cleft palate (58%). We found that OFCs are linked to birthweight, size, and gestational age and higher parity with statistically significant differences in all variables compared to controls. OFC is a highly prevalent anomaly in Colombia, with a range of maternal and infant differences across case subgroups. The identification of important OFC subgroups that follow certain patterns of prevalence may prove useful to primary and tertiary care facilities with the goal of reducing further disability.

Fragment-based drug discovery and molecular docking in drug design.

PubMed

Wang, Tao; Wu, Mian-Bin; Chen, Zheng-Jie; Chen, Hua; Lin, Jian-Ping; Yang, Li-Rong

2015-01-01

Fragment-based drug discovery (FBDD) has caused a revolution in the process of drug discovery and design, with many FBDD leads being developed into clinical trials or approved in the past few years. Compared with traditional high-throughput screening, it displays obvious advantages such as efficiently covering chemical space, achieving higher hit rates, and so forth. In this review, we focus on the most recent developments of FBDD for improving drug discovery, illustrating the process and the importance of FBDD. In particular, the computational strategies applied in the process of FBDD and molecular-docking programs are highlighted elaborately. In most cases, docking is used for predicting the ligand-receptor interaction modes and hit identification by structurebased virtual screening. The successful cases of typical significance and the hits identified most recently are discussed.

Information theory-based decision support system for integrated design of multivariable hydrometric networks

NASA Astrophysics Data System (ADS)

Keum, Jongho; Coulibaly, Paulin

2017-07-01

Adequate and accurate hydrologic information from optimal hydrometric networks is an essential part of effective water resources management. Although the key hydrologic processes in the water cycle are interconnected, hydrometric networks (e.g., streamflow, precipitation, groundwater level) have been routinely designed individually. A decision support framework is proposed for integrated design of multivariable hydrometric networks. The proposed method is applied to design optimal precipitation and streamflow networks simultaneously. The epsilon-dominance hierarchical Bayesian optimization algorithm was combined with Shannon entropy of information theory to design and evaluate hydrometric networks. Specifically, the joint entropy from the combined networks was maximized to provide the most information, and the total correlation was minimized to reduce redundant information. To further optimize the efficiency between the networks, they were designed by maximizing the conditional entropy of the streamflow network given the information of the precipitation network. Compared to the traditional individual variable design approach, the integrated multivariable design method was able to determine more efficient optimal networks by avoiding the redundant stations. Additionally, four quantization cases were compared to evaluate their effects on the entropy calculations and the determination of the optimal networks. The evaluation results indicate that the quantization methods should be selected after careful consideration for each design problem since the station rankings and the optimal networks can change accordingly.

Comparative Logic Modeling for Policy Analysis: The Case of HIV Testing Policy Change at the Department of Veterans Affairs

PubMed Central

Langer, Erika M; Gifford, Allen L; Chan, Kee

2011-01-01

Objective Logic models have been used to evaluate policy programs, plan projects, and allocate resources. Logic Modeling for policy analysis has been used rarely in health services research but can be helpful in evaluating the content and rationale of health policies. Comparative Logic Modeling is used here on human immunodeficiency virus (HIV) policy statements from the Department of Veterans Affairs (VA) and Centers for Disease Control and Prevention (CDC). We created visual representations of proposed HIV screening policy components in order to evaluate their structural logic and research-based justifications. Data Sources and Study Design We performed content analysis of VA and CDC HIV testing policy documents in a retrospective case study. Data Collection Using comparative Logic Modeling, we examined the content and primary sources of policy statements by the VA and CDC. We then quantified evidence-based causal inferences within each statement. Principal Findings VA HIV testing policy structure largely replicated that of the CDC guidelines. Despite similar design choices, chosen research citations did not overlap. The agencies used evidence to emphasize different components of the policies. Conclusion Comparative Logic Modeling can be used by health services researchers and policy analysts more generally to evaluate structural differences in health policies and to analyze research-based rationales used by policy makers. PMID:21689094

Performance Evaluation of Passive Haptic Feedback for Tactile HMI Design in CAVEs.

PubMed

Lassagne, Antoine; Kemeny, Andras; Posselt, Javier; Merienne, Frederic

2018-01-01

This article presents a comparison of different haptic systems, which are designed to simulate flat Human Machine Interfaces (HMIs) like touchscreens in virtual environments (VEs) such as CAVEs, and their respective performance. We compare a tangible passive transparent slate to a classic tablet and a sensory substitution system. These systems were tested during a controlled experiment. The performance and impressions from 20 subjects were collected to understand more about the modalities in the given context. The results show that the preferences of the subjects are strongly related to the use-cases and needs. In terms of performance, passive haptics proved to be significantly useful, acting as a space reference and a real-time continuous calibration system, allowing subjects to have lower execution durations and relative errors. Sensory substitution induced perception drifts during the experiment, causing significant performance disparities, demonstrating the low robustness of perception when spatial cues are insufficiently available. Our findings offer a better understanding on the nature of perception drifts and the need of strong multisensory spatial markers for such use-cases in CAVEs. The importance of a relevant haptic modality specifically designed to match a precise use-case is also emphasized.

Reliability assessment of slender concrete columns at the stability failure

NASA Astrophysics Data System (ADS)

Valašík, Adrián; Benko, Vladimír; Strauss, Alfred; Täubling, Benjamin

2018-01-01

The European Standard for designing concrete columns within the use of non-linear methods shows deficiencies in terms of global reliability, in case that the concrete columns fail by the loss of stability. The buckling failure is a brittle failure which occurs without warning and the probability of its formation depends on the columns slenderness. Experiments with slender concrete columns were carried out in cooperation with STRABAG Bratislava LTD in Central Laboratory of Faculty of Civil Engineering SUT in Bratislava. The following article aims to compare the global reliability of slender concrete columns with slenderness of 90 and higher. The columns were designed according to methods offered by EN 1992-1-1 [1]. The mentioned experiments were used as basis for deterministic nonlinear modelling of the columns and subsequent the probabilistic evaluation of structural response variability. Final results may be utilized as thresholds for loading of produced structural elements and they aim to present probabilistic design as less conservative compared to classic partial safety factor based design and alternative ECOV method.

Developing Mentors: Adult participation, practices, and learning in an out-of-school time STEM program

NASA Astrophysics Data System (ADS)

Scipio, Deana Aeolani

This dissertation examines learning within an out-of-school time (OST) Science, Technology, Engineering, and Mathematics (STEM) broadening participation program. The dissertation includes an introduction, three empirical chapters (written as individual articles), and a conclusion. The dissertation context is a chemical oceanography OST program for middle school students called Project COOL---Chemical Oceanography Outside the Lab. The program was a collaboration between middle school OST programming, a learning sciences research laboratory, and a chemical oceanography laboratory. Both labs were located at a research-based university in the Pacific Northwest of the United States. Participants include 34 youth, 12 undergraduates, and five professional scientists. The dissertation data corpus includes six years of ethnographic field notes across three field sites, 400 hours of video and audio recordings, 40 hours of semi-structured interviews, and more than 100 participant generated artifacts. Analysis methods include comparative case analysis, cognitive mapping, semiotic cluster analysis, video interaction analysis, and discourse analysis. The first empirical article focuses on synthesizing productive programmatic features from four years of design-based research.. The second article is a comparative case study of three STEM mentors from non-dominant communities in the 2011 COOL OST Program. The third article is a comparative case study of undergraduates learning to be mentors in the 2014 COOL OST Program. Findings introduce Deep Hanging as a theory of learning in practice. Deep Hanging entails authentic tasks in rich contexts, providing access, capitalizing on opportunity, and building interpersonal relationships. Taken together, these three chapters illuminate the process of designing a rich OST learning environment and the kinds of learning in practice that occurred for adult learners learning to be mentors through their participation in the COOL OST program. In the conclusion, I offer a set of design principles for mentor learning gleaned from empirical findings from the last two empirical chapters on how mentors can productively support the science learning of youth. The findings from this dissertation offer implications for designers of learning environments seeking to leverage experts for mentoring while engaging youth in contemporary science practices in order to broaden participation for youth and adult participants from non-dominant communities in STEM disciplines.

Risk factors for self-directed violence in US Soldiers: A case-control study.

PubMed

Skopp, Nancy A; Zhang, Ying; Smolenski, Derek J; Reger, Mark A

2016-11-30

Military suicide has escalated in recent years, however almost no research has used military surveillance data to examine suicide risk factors. The aims of the current study were to compare suicide risk factors among US Soldiers who died by suicide, attempted suicide, and controls using a prospective case-control design. Controls were 247 Soldiers completing standard post-deployment assessment procedures. Cases were 276 suicide decedents (n=85) or suicide attempters (n=191), drawn from the Department of Defense Suicide Event Report. Compared to controls, suicide attempters and decedents had greater odds of failed intimate relationships, legal problems, and substance abuse problems in the past 90 days. Suicide attempters and decedents also had greater odds of a history of a mood disorder and prior suicide attempt compared to controls. Suicide decedents had greater odds of exposure to legal problems in the past 90 days and lower odds of ever having an anxiety disorder, compared to suicide attempters. Vigilance toward early detection of modifiable suicide risk factors such as relationship dissolution, mood disorders, substance abuse, and legal problems may help reduce suicide risk among US Soldiers. Published by Elsevier Ireland Ltd.

Computer aided system engineering and analysis (CASE/A) modeling package for ECLS systems - An overview

NASA Technical Reports Server (NTRS)

Dalee, Robert C.; Bacskay, Allen S.; Knox, James C.

1990-01-01

An overview of the CASE/A-ECLSS series modeling package is presented. CASE/A is an analytical tool that has supplied engineering productivity accomplishments during ECLSS design activities. A components verification program was performed to assure component modeling validity based on test data from the Phase II comparative test program completed at the Marshall Space Flight Center. An integrated plotting feature has been added to the program which allows the operator to analyze on-screen data trends or get hard copy plots from within the CASE/A operating environment. New command features in the areas of schematic, output, and model management, and component data editing have been incorporated to enhance the engineer's productivity during a modeling program.

Scatterometry or imaging overlay: a comparative study

NASA Astrophysics Data System (ADS)

Hsu, Simon C. C.; Pai, Yuan Chi; Chen, Charlie; Yu, Chun Chi; Hsing, Henry; Wu, Hsing-Chien; Kuo, Kelly T. L.; Amir, Nuriel

2015-03-01

Most fabrication facilities today use imaging overlay measurement methods, as it has been the industry's reliable workhorse for decades. In the last few years, third-generation Scatterometry Overlay (SCOL™) or Diffraction Based Overlay (DBO-1) technology was developed, along another DBO technology (DBO-2). This development led to the question of where the DBO technology should be implemented for overlay measurements. Scatterometry has been adopted for high volume production in only few cases, always with imaging as a backup, but scatterometry overlay is considered by many as the technology of the future. In this paper we compare imaging overlay and DBO technologies by means of measurements and simulations. We outline issues and sensitivities for both technologies, providing guidelines for the best implementation of each. For several of the presented cases, data from two different DBO technologies are compared as well, the first with Pupil data access (DBO-1) and the other without pupil data access (DBO-2). Key indicators of overlay measurement quality include: layer coverage, accuracy, TMU, process robustness and robustness to process changes. Measurement data from real cases across the industry are compared and the conclusions are also backed by simulations. Accuracy is benchmarked with reference OVL, and self-consistency, showing good results for Imaging and DBO-1 technology. Process sensitivity and metrology robustness are mostly simulated with MTD (Metrology Target Designer) comparing the same process variations for both technologies. The experimental data presented in this study was done on ten advanced node layers and three production node layers, for all phases of the IC fabrication process (FEOL, MEOL and BEOL). The metrology tool used for most of the study is KLA-Tencor's Archer 500LCM system (scatterometry-based and imaging-based measurement technologies on the same tool) another type of tool is used for DBO-2 measurements. Finally, we conclude that both imaging overlay technology and DBO-1 technology are fully successful and have a valid roadmap for the next few design nodes, with some use cases better suited for one or the other measurement technologies. Having both imaging and DBO technology options available in parallel, allows Overlay Engineers a mix and match overlay measurement strategy, providing back up when encountering difficulties with one of the technologies and benefiting from the best of both technologies for every use case.

Design of microarray experiments for genetical genomics studies.

PubMed

Bueno Filho, Júlio S S; Gilmour, Steven G; Rosa, Guilherme J M

2006-10-01

Microarray experiments have been used recently in genetical genomics studies, as an additional tool to understand the genetic mechanisms governing variation in complex traits, such as for estimating heritabilities of mRNA transcript abundances, for mapping expression quantitative trait loci, and for inferring regulatory networks controlling gene expression. Several articles on the design of microarray experiments discuss situations in which treatment effects are assumed fixed and without any structure. In the case of two-color microarray platforms, several authors have studied reference and circular designs. Here, we discuss the optimal design of microarray experiments whose goals refer to specific genetic questions. Some examples are used to illustrate the choice of a design for comparing fixed, structured treatments, such as genotypic groups. Experiments targeting single genes or chromosomic regions (such as with transgene research) or multiple epistatic loci (such as within a selective phenotyping context) are discussed. In addition, microarray experiments in which treatments refer to families or to subjects (within family structures or complex pedigrees) are presented. In these cases treatments are more appropriately considered to be random effects, with specific covariance structures, in which the genetic goals relate to the estimation of genetic variances and the heritability of transcriptional abundances.

Farmers' Knowledge Attributes Contribute to Attaining Higher Farm Technical Efficiency: A Transition Economy Case

ERIC Educational Resources Information Center

Manevska-Tasevska, Gordana

2013-01-01

Purpose: This study sought to explore how farmers' knowledge attributes influence the technical efficiency of their farms. In addition, farm efficiency was compared to the actual Macedonian Rural Development Programme (RDP) (2007-2013) and instruments considered to improve Macedonian education potential were evaluated. Design/methodology/approach:…

Building Your Own Web Course: The Case for Off-the-Shelf Component Software.

ERIC Educational Resources Information Center

Kaplan, Howard

1998-01-01

Compares the features, advantages, and disadvantages of two major software options available for designing web courses: (1) component, off-the shelf software that allows for creation of audio slide lectures, course materials, discussion forums, animations, synchronous chat groups, quiz creators, and electronic mail, and (2) integrated packages…

Not Just Figureheads: Trustees as Microfoundations of Higher Education Institutions

ERIC Educational Resources Information Center

Barringer, Sondra N.; Riffe, Karley A.

2018-01-01

Despite the importance of trustees for higher education institutions, few studies address how they influence the institutions they steward. To address this gap, we used a social network approach within a comparative case study design to evaluate how trustees interacted with two private, elite universities: Harvard University and the Massachusetts…

Making Physiology Learning Memorable: A Mobile Phone-Assisted Case-Based Instructional Strategy

ERIC Educational Resources Information Center

Kukolja Taradi, S.; Taradi, M.

2016-01-01

The goal of the present study was to determine whether an active learning/teaching strategy facilitated with mobile technologies can improve students' levels of memory retention of key physiological concepts. We used a quasiexperimental pretest/posttest nonequivalent group design to compare the test performances of second-year medical students (n…

Leadership and the Design of Data-Driven Professional Networks in Schools

ERIC Educational Resources Information Center

Liou, Yi-Hwa; Grigg, Jeffrey; Halverson, Richard

2014-01-01

Using data from a multi-method comparative case study of two matched schools, this paper adds to the growing body of applications of social network analysis to the study of distributed leadership and accountability. We contrast two approaches to instructional leadership, prescriptive and discretionary, to investigate how leaders design…

Using National Inventories for Estimating Environmental Impacts of Products from Industrial Sectors: A Case Study of Ethanol and Gasoline

EPA Science Inventory

PurposeIn order to understand the environmental outcomes associated with the life cycle of a product, to compare these outcomes across products, or to design more sustainable supply chains, it is often desirable to estimate results for a reference supply chain representative of t...

Deutero-Learning: Implications for Managing Public Health Change

ERIC Educational Resources Information Center

Rowe, Patricia A.; Boyce, Rosalie A.

2009-01-01

Purpose: The purpose of this paper is to apply an allied health subculture model to clarify key contextual factors that can emerge in the evolution of an allied health subculture as a consequence of deutero-learning. Design/methodology/approach: Two case studies are compared to illustrate these two extreme variations in deutero-learning. Findings:…

The Inertial Property of Approximately Inertial Frames of Reference

ERIC Educational Resources Information Center

Chubykalo, Andrew E.; Espinoza, Augusto; Kosyakov, B. P.

2011-01-01

Is it possible to compare approximately inertial frames in the inertial property? If this is the case, the inertial property becomes a measurable quantity. We give a positive answer to this question, and discuss the general principle of design of devices for making the required measurements. This paper is intended for advanced undergraduate and…

Enhancing Cognitive Presence in Online Case Discussions with Questions Based on the Practical Inquiry Model

ERIC Educational Resources Information Center

Sadaf, Ayesha; Olesova, Larisa

2017-01-01

The researchers in this study examined the influence of questions designed with the Practical Inquiry Model (PIM), compared with the regular (playground) questions, on students' levels of cognitive presence in online discussions. Students' discussion postings were collected and categorized according to the four levels of cognitive presence:…

Adult Day Health Center Participation and Health-Related Quality of Life

ERIC Educational Resources Information Center

Schmitt, Eva M.; Sands, Laura P.; Weiss, Sara; Dowling, Glenna; Covinsky, Kenneth

2010-01-01

Purpose: The purpose of this study was to assess the association between Adult Day Health Center (ADHC) participation and health-related quality of life. Design and Methods: Case-controlled prospective study utilizing the Medical Outcomes Survey Form 36 (SF-36) to compare newly enrolled participants from 16 ADHC programs with comparable…

Qualitative Inquiry and Research Design: Choosing among Five Approaches [with CD-ROM]. Second Edition

ERIC Educational Resources Information Center

Creswell, John W.

2006-01-01

This new version explores the philosophical underpinnings, history, and key elements of each of five qualitative inquiry approaches: narrative research, phenomenology, grounded theory, ethnography, and case study. Using an accessible and engaging writing style, the author compares theoretical frameworks, ways to employ standards of quality, and…

Blended Learning from Design to Evaluation: International Case Studies of Evidence-Based Practice

ERIC Educational Resources Information Center

Vaughan, Norman; Reali, Aline; Stenbom, Stefan; Van Vuuren, Marieta Jansen; MacDonald, David

2017-01-01

This study compares and contrasts four international faculty development programs for blended learning in order to understand the benefits, challenges, lessons learned, and recommendations from such initiatives. The benefits identified for faculty members, who participated in these programs, were that they became more reflective of their teaching…

Novel application of the matched case-control design to compare food supply chains during an Escherichia coli O157 outbreak, United Kingdom, 2016.

PubMed

Inns, Thomas; Cleary, Paul; Bundle, Nick; Foulkes, Sarah; Sharp, Ashley; Utsi, Lara; McBrien, Chris; Teagle, Rehman; Waldram, Alison; Williams, Chris; McCann, Cathy; Smith, Rob; Saleh, Sepeedeh; McCarthy, Noel; Vivancos, Roberto; Hawker, Jeremy; Decraene, Valerie

2018-05-01

There is a need for innovative methods to investigate outbreaks of food-borne infection linked to produce with a complex distribution network. The investigation of a large outbreak of Escherichia coli O157 PT34 infection in the United Kingdom in 2016 indicated that catering venues associated with multiple cases had used salad leaves sourced from one supplier. Our aim was to investigate whether catering venues linked to cases were more likely to have used salad leaves from this supplier. We conducted a matched case-control study, with catering venues as the units of analysis. We compared venues linked to cases to those without known linked cases. We included 43 study pairs and obtained information on salad leaf products received by each venue. The odds of a case venue being supplied with salad leaves by Supplier A were 7.67 times (95% confidence interval: 2.30-25.53) those of control venues. This association provided statistical evidence to support the findings of the other epidemiological investigations undertaken for this outbreak. This is a novel approach which is labour-intensive but which addresses the challenge of investigating exposures to food across a complex distribution network.

Investigation of conjugate circular arcs in rocket nozzle contour design

NASA Astrophysics Data System (ADS)

Schomberg, K.; Olsen, J.; Neely, A.; Doig, G.

2018-05-01

The use of conjugate circular arcs in rocket nozzle contour design has been investigated by numerically comparing three existing sub-scale nozzles to a range of equivalent arc-based contour designs. Three performance measures were considered when comparing nozzle designs: thrust coefficient, nozzle exit wall pressure, and a transition between flow separation regimes during the engine start-up phase. In each case, an equivalent arc-based contour produced an increase in the thrust coefficient and exit wall pressure of up to 0.4 and 40% respectively, in addition to suppressing the transition between a free and restricted shock separation regime. A general approach to arc-based nozzle contour design has also been presented to outline a rapid and repeatable process for generating sub-scale arc-based contours with an exit Mach number of 3.8-5.4 and a length between 60 and 100% of a 15° conical nozzle. The findings suggest that conjugate circular arcs may represent a viable approach for producing sub-scale rocket nozzle contours, and that a further investigation is warranted between arc-based and existing full-scale rocket nozzles.

Interactive Land-Use Optimization Using Laguerre Voronoi Diagram with Dynamic Generating Point Allocation

NASA Astrophysics Data System (ADS)

Chaidee, S.; Pakawanwong, P.; Suppakitpaisarn, V.; Teerasawat, P.

2017-09-01

In this work, we devise an efficient method for the land-use optimization problem based on Laguerre Voronoi diagram. Previous Voronoi diagram-based methods are more efficient and more suitable for interactive design than discrete optimization-based method, but, in many cases, their outputs do not satisfy area constraints. To cope with the problem, we propose a force-directed graph drawing algorithm, which automatically allocates generating points of Voronoi diagram to appropriate positions. Then, we construct a Laguerre Voronoi diagram based on these generating points, use linear programs to adjust each cell, and reconstruct the diagram based on the adjustment. We adopt the proposed method to the practical case study of Chiang Mai University's allocated land for a mixed-use complex. For this case study, compared to other Voronoi diagram-based method, we decrease the land allocation error by 62.557 %. Although our computation time is larger than the previous Voronoi-diagram-based method, it is still suitable for interactive design.

Summary of Data from the First AIAA CFD Drag Prediction Workshop

NASA Technical Reports Server (NTRS)

Levy, David W.; Zickuhr, Tom; Vassberg, John; Agrawal, Shreekant; Wahls, Richard A.; Pirzadeh, Shahyar; Hemsch, Michael J.

2002-01-01

The results from the first AIAA CFD Drag Prediction Workshop are summarized. The workshop was designed specifically to assess the state-of-the-art of computational fluid dynamics methods for force and moment prediction. An impartial forum was provided to evaluate the effectiveness of existing computer codes and modeling techniques, and to identify areas needing additional research and development. The subject of the study was the DLR-F4 wing-body configuration, which is representative of transport aircraft designed for transonic flight. Specific test cases were required so that valid comparisons could be made. Optional test cases included constant-C(sub L) drag-rise predictions typically used in airplane design by industry. Results are compared to experimental data from three wind tunnel tests. A total of 18 international participants using 14 different codes submitted data to the workshop. No particular grid type or turbulence model was more accurate, when compared to each other, or to wind tunnel data. Most of the results overpredicted C(sub Lo) and C(sub Do), but induced drag (dC(sub D)/dC(sub L)(exp 2)) agreed fairly well. Drag rise at high Mach number was underpredicted, however, especially at high C(sub L). On average, the drag data were fairly accurate, but the scatter was greater than desired. The results show that well-validated Reynolds-Averaged Navier-Stokes CFD methods are sufficiently accurate to make design decisions based on predicted drag.

The case-control design in veterinary sciences: A survey.

PubMed

Cullen, Jonah N; Sargeant, Jan M; Makielski, Kelly M; O'Connor, Annette M

2016-11-01

The case-control study design is deceptively simple. However, many design considerations influence the estimated effect measure. An investigation of case-control studies in the human health literature suggested that some of these considerations are not described in reports of case-control studies. Our hypothesis was that the majority of veterinary studies labeled as case-controls would be incident density designs, and many would not interpret the effect measure obtained from those studies as the rate ratio rather than the odds ratio. Reference databases were searched for author-designated case-control studies. A survey of 100 randomly selected studies was conducted to examine the different design options described and estimated effect measures. Of the 100 author-identified case-control studies, 83 assessed an exposure-outcome association and, of those, only 54 (65.1%) sampled the study population based on an outcome and would thus be considered case-control designs. Twelve studies were incidence density designs but none used this terminology. Of the studies that reported an odds ratio as the effect measure, none reported on additional considerations that would have enabled a more interpretable result. This survey indicated many case-control-labeled studies were not case-control designs and among case-control studies, key design aspects were not often described. The absence of information about study design elements and underlying assumptions in case-control studies limits the ability to establish the effect measured by the study and the evidentiary value of the study might be underestimated. Copyright © 2016 Elsevier B.V. All rights reserved.

Making a Case for a Blended Approach: The Need for The Design-Based Case Study

ERIC Educational Resources Information Center

Deaton, Cynthia C. M.; Malloy, Jacquelynn A.

2017-01-01

Design-based case studies address research questions that involve instructional innovations within a bounded system. This blend of case study and design-based research provides a systematic approach to examining instructional innovations that are bounded by perspective, context, and time. Design-based case studies provide a framework for engaging…

Impact of a Paper vs Virtual Simulated Patient Case on Student-Perceived Confidence and Engagement

PubMed Central

Gallimore, Casey E.; Pitterle, Michael; Morrill, Josh

2016-01-01

Objective. To evaluate online case simulation vs a paper case on student confidence and engagement. Design. Students enrolled in a pharmacotherapy laboratory course completed a patient case scenario as a component of an osteoarthritis laboratory module. Two laboratory sections used a paper case (n=53); three sections used an online virtual case simulation (n=81). Student module performance was assessed through a submitted subjective objective assessment plan (SOAP) note. Students completed pre/post surveys to measure self-perceived confidence in providing medication management. The simulation group completed postmodule questions related to realism and engagement of the online virtual case simulation. Group assessments were performed using chi-square and Mann Whitney tests. Assessment. A significant increase in all 13 confidence items was seen in both student groups following completion of the laboratory module. The simulation group had an increased change of confidence compared to the paper group in assessing medication efficacy and documenting a thorough assessment. Comparing the online virtual simulation to a paper case, students agreed the learning experience increased interest, enjoyment, relevance, and realism. The simulation group performed better on the subjective SOAP note domain though no differences in total SOAP note scores was found between the two groups. Conclusion. Virtual case simulations result in increased student engagement and may lead to improved documentation performance in the subjective domain of SOAP notes. However, virtual patient cases may offer limited benefit over paper cases in improving overall student self-confidence to provide medication management. PMID:26941442

Till receipts--a new approach for investigating outbreaks? Evaluation during a large Salmonella Enteritidis phage type 14b outbreak in a North West London takeaway restaurant, September 2009.

PubMed

Zenner, D; Zoellner, J; Charlett, A; Marmairis, W; Lane, C; Chow, J Y

2014-07-10

Selecting suitable controls for outbreak investigations is often difficult and if done inappropriately will lead to biased inferences. Till receipts and other sales records are frequently available on food premises, but their applicability has not been fully explored. Using data from an investigation into a Salmonella outbreak affecting 66 individuals exposed in a London takeaway restaurant, this study aimed to evaluate the use of till receipts to assess associations between sales and illness. Cases identified through local case-finding were subjected to a standardised exposure questionnaire. Till receipts over the time period when cases arose were analysed. Estimated food exposures from sales were compared to case reported exposures and till receipts analysis showed strong association between illness and consumption of rotisserie chicken (odds ratio (OR): 2.75; confidence interval (CI): 1.7-4.5). Chicken sales immediately prior to food consumption for cases were compared to two control periods in an ecological case-crossover design. On average there was an estimated increase of 3.7 (CI: 2.2-5.2) extra chickens sold in the hour immediately prior to the consumption in the cases (p<0.0001) and the risk of becoming ill at busy times increased by 5% with each additional chicken quarter sold per hour (OR: 1.05; CI: 1.03-1.08). Microbiological and environmental investigations revealed Salmonella Enteritidis phage type (PT)14b in all available cases' stool samples, two environmental samples and leftover chicken from the takeaway. The feasibility of this novel approach to obtain exposure information in the population at risk has been demonstrated, and its limitations are discussed. Further validation is required, comparing results with those in a concurrent classic case-control study.

[Implementation and (cost-)effectiveness of case management for people with dementia and their informal caregivers: results of the COMPAS study].

PubMed

van Mierlo, Lisa D; MacNeil-Vroomen, Janet; Meiland, Franka J M; Joling, Karlijn J; Bosmans, Judith E; Dröes, Rose Marie; Moll van Charante, Eric P; de Rooij, Sophia E J A; van Hout, Hein P J

2016-12-01

Different forms of case management for dementia have emerged over the past few years. In the COMPAS study (Collaborative dementia care for patients and caregivers study), two prominent Dutch case management forms were studied: the linkage and the integrated care form. Evaluation of the (cost)effectiveness of two dementia case management forms compared to usual care as well as factors that facilitated or impeded their implementation. A mixed methods design with a) a prospective, observational controlled cohort study with 2 years follow-up among 521 dyads of people with dementia and their primary informal caregiver with and without case management; b) interviews with 22 stakeholders on facilitating and impeding factors of the implementation and continuity of the two case management models. Outcome measures were severity and frequency of behavioural problems (NPI) for the person with dementia and mental health complaints (GHQ-12) for the informal caregiver, total met and unmet care needs (CANE) and quality adjusted life years (QALYs). Outcomes showed a better quality of life of informal caregivers in the integrated model compared to the linkage model. Caregivers in the control group reported more care needs than those in both case management groups. The independence of the case management provider in the integrated model facilitated the implementation, while the rivalry between multiple providers in the linkage model impeded the implementation. The costs of care were lower in the linkage model (minus 22 %) and integrated care model (minus 33 %) compared to the control group. The integrated care form was (very) cost-effective in comparison with the linkage form or no case management. The integrated care form is easy to implement.

Worst case analysis: Earth sensor assembly for the tropical rainfall measuring mission observatory

NASA Technical Reports Server (NTRS)

Conley, Michael P.

1993-01-01

This worst case analysis verifies that the TRMMESA electronic design is capable of maintaining performance requirements when subjected to worst case circuit conditions. The TRMMESA design is a proven heritage design and capable of withstanding the most worst case and adverse of circuit conditions. Changes made to the baseline DMSP design are relatively minor and do not adversely effect the worst case analysis of the TRMMESA electrical design.

Association between the 2008–09 Seasonal Influenza Vaccine and Pandemic H1N1 Illness during Spring–Summer 2009: Four Observational Studies from Canada

PubMed Central

Skowronski, Danuta M.; De Serres, Gaston; Crowcroft, Natasha S.; Janjua, Naveed Z.; Boulianne, Nicole; Hottes, Travis S.; Rosella, Laura C.; Dickinson, James A.; Gilca, Rodica; Sethi, Pam; Ouhoummane, Najwa; Willison, Donald J.; Rouleau, Isabelle; Petric, Martin; Fonseca, Kevin; Drews, Steven J.; Rebbapragada, Anuradha; Charest, Hugues; Hamelin, Marie-Ève; Boivin, Guy; Gardy, Jennifer L.; Li, Yan; Kwindt, Trijntje L.; Patrick, David M.; Brunham, Robert C.

2010-01-01

Background In late spring 2009, concern was raised in Canada that prior vaccination with the 2008–09 trivalent inactivated influenza vaccine (TIV) was associated with increased risk of pandemic influenza A (H1N1) (pH1N1) illness. Several epidemiologic investigations were conducted through the summer to assess this putative association. Methods and Findings Studies included: (1) test-negative case-control design based on Canada's sentinel vaccine effectiveness monitoring system in British Columbia, Alberta, Ontario, and Quebec; (2) conventional case-control design using population controls in Quebec; (3) test-negative case-control design in Ontario; and (4) prospective household transmission (cohort) study in Quebec. Logistic regression was used to estimate odds ratios for TIV effect on community- or hospital-based laboratory-confirmed seasonal or pH1N1 influenza cases compared to controls with restriction, stratification, and adjustment for covariates including combinations of age, sex, comorbidity, timeliness of medical visit, prior physician visits, and/or health care worker (HCW) status. For the prospective study risk ratios were computed. Based on the sentinel study of 672 cases and 857 controls, 2008–09 TIV was associated with statistically significant protection against seasonal influenza (odds ratio 0.44, 95% CI 0.33–0.59). In contrast, estimates from the sentinel and three other observational studies, involving a total of 1,226 laboratory-confirmed pH1N1 cases and 1,505 controls, indicated that prior receipt of 2008–09 TIV was associated with increased risk of medically attended pH1N1 illness during the spring–summer 2009, with estimated risk or odds ratios ranging from 1.4 to 2.5. Risk of pH1N1 hospitalization was not further increased among vaccinated people when comparing hospitalized to community cases. Conclusions Prior receipt of 2008–09 TIV was associated with increased risk of medically attended pH1N1 illness during the spring–summer 2009 in Canada. The occurrence of bias (selection, information) or confounding cannot be ruled out. Further experimental and epidemiological assessment is warranted. Possible biological mechanisms and immunoepidemiologic implications are considered. Please see later in the article for the Editors' Summary PMID:20386731

Cost-effectiveness analysis of a system-based approach for managing neonatal jaundice and preventing kernicterus in Ontario

PubMed Central

Xie, Bin; da Silva, Orlando; Zaric, Greg

2012-01-01

OBJECTIVE: To evaluate the incremental cost-effectiveness of a system-based approach for the management of neonatal jaundice and the prevention of kernicterus in term and late-preterm (≥35 weeks) infants, compared with the traditional practice based on visual inspection and selected bilirubin testing. STUDY DESIGN: Two hypothetical cohorts of 150,000 term and late-preterm neonates were used to compare the costs and outcomes associated with the use of a system-based or traditional practice approach. Data for the evaluation were obtained from the case costing centre at a large teaching hospital in Ontario, supplemented by data from the literature. RESULTS: The per child cost for the system-based approach cohort was $176, compared with $173 in the traditional practice cohort. The higher cost associated with the system-based cohort reflects increased costs for predischarge screening and treatment and increased postdischarge follow-up visits. These costs are partially offset by reduced costs from fewer emergency room visits, hospital readmissions and kernicterus cases. Compared with the traditional approach, the cost to prevent one kernicterus case using the system-based approach was $570,496, the cost per life year gained was $26,279, and the cost per quality-adjusted life year gained was $65,698. CONCLUSION: The cost to prevent one kernicterus case using the system-based approach is much lower than previously reported in the literature. PMID:23277747

Have we progressed in the surgical literature? Thirty-year trends in clinical studies in 3 surgical journals.

PubMed

Shawhan, Robert R; Hatch, Quinton M; Bingham, Jason R; Nelson, Daniel W; Fitzpatrick, Emile B; McLeod, Robin; Johnson, Eric K; Maykel, Justin A; Steele, Scott R

2015-01-01

We practice in an era of evidence-based medicine. In 1993, Solomon and McLeod published an article examining study designs in 3 surgical journals from 1980 and 1990. The purpose of this study was to evaluate subsequent 30-year trends in the quality of selected literature. All of the articles from Diseases of the Colon & Rectum, Surgery, and the British Journal of Surgery during 2000 and 2010 were classified by study design. Nonclinical studies were substratified by animal/laboratory, surgical technique, editorial/review, or miscellaneous articles. Clinical articles were categorized as case or comparative studies, further categorized by study design, and rated on a 10-point scale to determine strength. We compared interobserver reliability using a random sample. This study was conducted at 3 North American medical centers. Patients described in the scope of the literature were included in this study. Frequency, type, and strength of study design were measured. We evaluated 1911 articles (967 clinical; 17% comparative). There was a significant increase in multicenter clinical studies (from 12% to 27%; p < 0.0001) and mean study population (from 326 to 6775; p < 0.05). Studies using administrative data increased from 14% to 43% (p < 0.0001). Case reports decreased from 16% to 7% of all clinical studies (p < 0.001), whereas the percentage of comparative studies increased from 14% to 21% (p = 0.001). The percentage of randomized controlled trials did not increase significantly (8.5% in 2000; 10.0% in 2010; p = 0.44). The mean 10-point score for comparative studies was 6.7 for both years (p = 0.50). There was good interobserver agreement in the classification of studies (κ = 0.70) and moderate agreement in scoring comparative studies (κ = 0.47). This descriptive study cannot fully account for the reasons behind the identified differences. Comparative and multicenter studies, mean study population, and the use of administrative data increased from 2000 to 2010. This suggests that increased use of administrative databases has allowed larger populations of patients from more institutions to be studied and may be more generalizable. Researchers should strive toward improving the level of evidence (see Video, Supplemental Digital Content 1, http://links.lww.com/DCR/A167).

Research Methods in Healthcare Epidemiology and Antimicrobial Stewardship-Observational Studies.

PubMed

Snyder, Graham M; Young, Heather; Varman, Meera; Milstone, Aaron M; Harris, Anthony D; Munoz-Price, Silvia

2016-10-01

Observational studies compare outcomes among subjects with and without an exposure of interest, without intervention from study investigators. Observational studies can be designed as a prospective or retrospective cohort study or as a case-control study. In healthcare epidemiology, these observational studies often take advantage of existing healthcare databases, making them more cost-effective than clinical trials and allowing analyses of rare outcomes. This paper addresses the importance of selecting a well-defined study population, highlights key considerations for study design, and offers potential solutions including biostatistical tools that are applicable to observational study designs. Infect Control Hosp Epidemiol 2016;1-6.

Mature thunderstorm cloud-top structure and dynamics - A three-dimensional numerical simulation study

NASA Technical Reports Server (NTRS)

Schlesinger, R. E.

1984-01-01

The present investigation is concerned with results from an initial set of comparative experiments in a project which utilize a three-dimensional convective storm model. The modeling results presented are related to four comparative experiments, designated Cases A through D. One of two scientific questions considered involves the dynamical processes, either near the cloud top or well within the cloud interior, which contribute to organize cloud thermal patterns such as those revealed by IR satellite imagery for some storms having strong internal cloud-scale rotation. The second question is concerned with differences, in cloud-top height and temperature field characteristics, between thunderstorms with and without significant internal cloud-scale rotation. The four experiments A-D are compared with regard to both interior and cloud-top configurations in the context of the second question. A particular strong-shear experiment, Case B, is analyzed to address question one.

Comparative study of two approaches to model the offshore fish cages

NASA Astrophysics Data System (ADS)

Zhao, Yun-peng; Wang, Xin-xin; Decew, Jud; Tsukrov, Igor; Bai, Xiao-dong; Bi, Chun-wei

2015-06-01

The goal of this paper is to provide a comparative analysis of two commonly used approaches to discretize offshore fish cages: the lumped-mass approach and the finite element technique. Two case studies are chosen to compare predictions of the LMA (lumped-mass approach) and FEA (finite element analysis) based numerical modeling techniques. In both case studies, we consider several loading conditions consisting of different uniform currents and monochromatic waves. We investigate motion of the cage, its deformation, and the resultant tension in the mooring lines. Both model predictions are sufficient close to the experimental data, but for the first experiment, the DUT-FlexSim predictions are slightly more accurate than the ones provided by Aqua-FE™. According to the comparisons, both models can be successfully utilized to the design and analysis of the offshore fish cages provided that an appropriate safety factor is chosen.

Case-control Studies on the Effectiveness of Breast Cancer Screening: Insights from the UK Age Trial.

PubMed

van der Waal, Daniëlle; Broeders, Mireille J M; Verbeek, André L M; Duffy, Stephen W; Moss, Sue M

2015-07-01

Ongoing breast cancer screening programs can only be evaluated using observational study designs. Most studies have observed a reduction in breast cancer mortality, but design differences appear to have resulted in different estimates. Direct comparison of case-control and trial analyses gives more insight into this variation. Here, we performed case-control analyses within the randomized UK Age Trial. The Age Trial assessed the effect of screening on breast cancer mortality in women ages 40-49 years. In our approach, case subjects were defined as breast cancer deaths between trial entry (1991-1997) and 2004. Women were ages 39-41 years at entry. For every case subject, five control subjects were selected. All case subjects were included in analyses of screening invitation (356 case subjects, 1,780 controls), whereas analyses of attendance were restricted to women invited to screening (105 case subjects, 525 age-matched controls). Odds ratios (OR) were estimated with conditional logistic regression. We used and compared two methods to correct for self-selection bias. Screening invitation resulted in a breast cancer mortality reduction of 17% (95% confidence interval [CI]: -36%, +6%), similar to trial results. Different exposure definitions and self-selection adjustments influenced the observed breast cancer mortality reduction. Depending on the method, "ever screened" appeared to be associated with a small reduction (OR: 0.86, 95% CI: 0.40, 1.89) or no reduction (OR: 1.02, 95% CI: 0.48, 2.14) using the two methods of correction. Recent attendance resulted in an adjusted mortality reduction of 36% (95% CI: -69%, +31%) or 45% (95% CI: -71%, +5%). Observational studies, and particularly case-control studies, are an important monitoring tool for breast cancer screening programs. The focus should be on diminishing bias in observational studies and gaining a better understanding of the influence of study design on estimates of mortality reduction.

Numerical tool for SMA material simulation: application to composite structure design

NASA Astrophysics Data System (ADS)

Chemisky, Yves; Duval, Arnaud; Piotrowski, Boris; Ben Zineb, Tarak; Tahiri, Vanessa; Patoor, Etienne

2009-10-01

Composite materials based on shape memory alloys (SMA) have received growing attention over these last few years. In this paper, two particular morphologies of composites are studied. The first one is an SMA/elastomer composite in which a snake-like wire NiTi SMA is embedded into an elastomer ribbon. The second one is a commercial Ni47Ti44Nb9 which presents elastic-plastic inclusions in an NiTi SMA matrix. In both cases, the design of such composites required the development of an SMA design tool, based on a macroscopic 3D constitutive law for NiTi alloys. Two different strategies are then applied to compute these composite behaviors. For the SMA/elastomer composite, the macroscopic behavior law is implemented in commercial FEM software, and for the Ni47Ti44Nb9 a scale transition approach based on the Mori-Tanaka scheme is developed. In both cases, simulations are compared to experimental data.

Feasibility and design study of a frictionless air mover for thermal management of electronics

NASA Astrophysics Data System (ADS)

Schacht, R.; Hausdorf, A.; Wunderle, B.

2014-07-01

A frictionless air mover concept is introduced in this paper. As opposed to a piezoelectric driven fan, the air mover is based on a flexible blade whose vibration is driven by means of a magnetic field. The blade is based on a polymer material. The paper presents the results of a feasibility analysis and an on-going comprehensive design study. The performance of the prototype amounted to 65% of a comparable piezoelectric fan. To enhance the performance, two different blade materials were investigated, as well as the influence of the coil shape and value. A further goal is to reduce the size and to investigate the influence of a casing. The design study resulted in a prototype of size of 50 × 14 × 35 mm2 including a casing. The performance could be doubled, to attain a volumetric flow rate of dot V ~14 l/min and a static pressure of ρstat = 3 Pa.

A Comparative Study : Microprogrammed Vs Risc Architectures For Symbolic Processing

NASA Astrophysics Data System (ADS)

Heudin, J. C.; Metivier, C.; Demigny, D.; Maurin, T.; Zavidovique, B.; Devos, F.

1987-05-01

It is oftenclaimed that conventional computers are not well suited for human-like tasks : Vision (Image Processing), Intelligence (Symbolic Processing) ... In the particular case of Artificial Intelligence, dynamic type-checking is one example of basic task that must be improved. The solution implemented in most Lisp work-stations consists in a microprogrammed architecture with a tagged memory. Another way to gain efficiency is to design a well suited instruction set for symbolic processing, which reduces the semantic gap between the high level language and the machine code. In this framework, the RISC concept provides a convenient approach to study new architectures for symbolic processing. This paper compares both approaches and describes our projectof designing a compact symbolic processor for Artificial Intelligence applications.

Verification of a Constraint Force Equation Methodology for Modeling Multi-Body Stage Separation

NASA Technical Reports Server (NTRS)

Tartabini, Paul V.; Roithmayr, Carlos; Toniolo, Matthew D.; Karlgaard, Christopher; Pamadi, Bandu N.

2008-01-01

This paper discusses the verification of the Constraint Force Equation (CFE) methodology and its implementation in the Program to Optimize Simulated Trajectories II (POST2) for multibody separation problems using three specially designed test cases. The first test case involves two rigid bodies connected by a fixed joint; the second case involves two rigid bodies connected with a universal joint; and the third test case is that of Mach 7 separation of the Hyper-X vehicle. For the first two cases, the POST2/CFE solutions compared well with those obtained using industry standard benchmark codes, namely AUTOLEV and ADAMS. For the Hyper-X case, the POST2/CFE solutions were in reasonable agreement with the flight test data. The CFE implementation in POST2 facilitates the analysis and simulation of stage separation as an integral part of POST2 for seamless end-to-end simulations of launch vehicle trajectories.

Case Study: The Application of ISO 9001:2000 to a Government Organization: A Study of the Benefits, Drawbacks and Effectiveness of ISO 9001:2000 for Navy Undersea Range Programs

DTIC Science & Technology

2004-09-01

the organization: “understanding” is a nebulous term to measure without applying some form of academic rigor, which in this case would be complex...to the RSDBU ISO 9001:2000 certification initiative was based on the work of University of Rhode Island Professor Quentin C. Turtle . His book...commensurate inspection protocol during design and production phases.84 The major difference in the Turtle approach compared to ISO 9000 is that Turtle

Effect of peripheral irregularities in the temperature field during turbine startups with flange heating along the reduction on the durability of turbine casings

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

Beryland, V.I.; Glyadya, A.A.; Pozhidaev, A.V.

1982-07-01

One method for improving the operating flexibility of 150, 200, and 300 MW steam turbines is heating the flanges of the horizontal casing point during startup, both when cold and before cooling down. A design analysis was conducted of the comparative effectiveness of various heating systems from the standpoint of minimizing both temperature differences across the flange width, as well as the level of related thermal stresses. The effects of flange heating during the entire operating period are discussed.

Design and analysis of roll cage

NASA Astrophysics Data System (ADS)

Angadi, Gurusangappa; Chetan, S.

2018-04-01

Wildlife fire fighting vehicles are used to extinguish fires in forests, in this process vehicles face falling objects like rocks, tree branches and other objects. Also due to uneven conditions of the terrain like cliff edges, uneven surfaces etc. makes the vehicle to roll over and these can cause injuries to both the driver and the operator. Roll over of a vehicle is a common incident which makes fatal injuries to the operator and also stands next to the crash accidents. In order to reduce the injury level and continuous roll over of the vehicle it is necessary to equip suitable roll cage according to standards of vehicle. In this present work roll cage for pump operator in wildfire fighting vehicle is designed and analysis is carried out in computer simulated environment when seating position of operator seated outside of the cabin. According to NFPA 1906 standards wildlife fire apparatus, Design and Test procedures that are carried out in Hyperworks maintaining SAE J1194.1983 standards. G load case, roof crush analysis and pendulum impact analysis tests are carried out on roll cage to ensure the saftey of design. These load cases are considerd to satisfy the situation faced in forest terrain. In these test procedures roll cage is analysed for stresses and deformation in various load cases. After recording results these are compared with standards mentioned in SAE J1194.1983.

Network-based regularization for matched case-control analysis of high-dimensional DNA methylation data.

PubMed

Sun, Hokeun; Wang, Shuang

2013-05-30

The matched case-control designs are commonly used to control for potential confounding factors in genetic epidemiology studies especially epigenetic studies with DNA methylation. Compared with unmatched case-control studies with high-dimensional genomic or epigenetic data, there have been few variable selection methods for matched sets. In an earlier paper, we proposed the penalized logistic regression model for the analysis of unmatched DNA methylation data using a network-based penalty. However, for popularly applied matched designs in epigenetic studies that compare DNA methylation between tumor and adjacent non-tumor tissues or between pre-treatment and post-treatment conditions, applying ordinary logistic regression ignoring matching is known to bring serious bias in estimation. In this paper, we developed a penalized conditional logistic model using the network-based penalty that encourages a grouping effect of (1) linked Cytosine-phosphate-Guanine (CpG) sites within a gene or (2) linked genes within a genetic pathway for analysis of matched DNA methylation data. In our simulation studies, we demonstrated the superiority of using conditional logistic model over unconditional logistic model in high-dimensional variable selection problems for matched case-control data. We further investigated the benefits of utilizing biological group or graph information for matched case-control data. We applied the proposed method to a genome-wide DNA methylation study on hepatocellular carcinoma (HCC) where we investigated the DNA methylation levels of tumor and adjacent non-tumor tissues from HCC patients by using the Illumina Infinium HumanMethylation27 Beadchip. Several new CpG sites and genes known to be related to HCC were identified but were missed by the standard method in the original paper. Copyright © 2012 John Wiley & Sons, Ltd.

Vital Signs: How Early Can Resident Evaluation Predict Acquisition of Competency in Surgical Pathology?

PubMed Central

Ducatman, Barbara S.; Williams, H. James; Hobbs, Gerald; Gyure, Kymberly A.

2009-01-01

Objectives To determine whether a longitudinal, case-based evaluation system can predict acquisition of competency in surgical pathology and how trainees at risk can be identified early. Design Data were collected for trainee performance on surgical pathology cases (how well their diagnosis agreed with the faculty diagnosis) and compared with training outcomes. Negative training outcomes included failure to complete the residency, failure to pass the anatomic pathology component of the American Board of Pathology examination, and/or failure to obtain or hold a position immediately following training. Findings Thirty-three trainees recorded diagnoses for 54 326 surgical pathology cases, with outcome data available for 15 residents. Mean case-based performance was significantly higher for those with positive outcomes, and outcome status could be predicted as early as postgraduate year-1 (P  =  .0001). Performance on the first postgraduate year-1 rotation was significantly associated with the outcome (P  =  .02). Although trainees with unsuccessful outcomes improved their performance more rapidly, they started below residents with successful outcomes and did not make up the difference during training. There was no significant difference in Step 1 or 2 United States Medical Licensing Examination (USMLE) scores when compared with performance or final outcomes (P  =  .43 and P  =  .68, respectively) and the resident in-service examination (RISE) had limited predictive ability. Discussion Differences between successful- and unsuccessful-outcome residents were most evident in early residency, ideal for designing interventions or counseling residents to consider another specialty. Conclusion Our longitudinal case-based system successfully identified trainees at risk for failure to acquire critical competencies for surgical pathology early in the program. PMID:21975705

Defrost Temperature Termination in Supermarket Refrigeration Systems

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

Fricke, Brian A; Sharma, Vishaldeep

2011-11-01

The objective of this project was to determine the potential energy savings associated with implementing demand defrost strategies to defrost supermarket refrigerated display case evaporators, as compared to the widely accepted current practice of controlling display case defrost cycles with a preset timer. The defrost heater energy use of several representative display case types was evaluated. In addition, demand defrost strategies for refrigerated display cases as well as those used in residential refrigerator/freezers were evaluated. Furthermore, it is anticipated that future work will include identifying a preferred defrost strategy, with input from Retail Energy Alliance members. Based on this strategy,more » a demand defrost system will be designed which is suitable for supermarket refrigerated display cases. Limited field testing of the preferred defrost strategy will be performed in a supermarket environment.« less

Designing effective animations for computer science instruction

NASA Astrophysics Data System (ADS)

Grillmeyer, Oliver

This study investigated the potential for animations of Scheme functions to help novice computer science students understand difficult programming concepts. These animations used an instructional framework inspired by theories of constructivism and knowledge integration. The framework had students make predictions, reflect, and specify examples to animate to promote autonomous learning and result in more integrated knowledge. The framework used animated pivotal cases to help integrate disconnected ideas and restructure students' incomplete ideas by illustrating weaknesses in their existing models. The animations scaffolded learners, making the thought processes of experts more visible by modeling complex and tacit information. The animation design was guided by prior research and a methodology of design and refinement. Analysis of pilot studies led to the development of four design concerns to aid animation designers: clearly illustrate the mapping between objects in animations with the actual objects they represent, show causal connections between elements, draw attention to the salient features of the modeled system, and create animations that reduce complexity. Refined animations based on these design concerns were compared to computer-based tools, text-based instruction, and simpler animations that do not embody the design concerns. Four studies comprised this dissertation work. Two sets of animated presentations of list creation functions were compared to control groups. No significant differences were found in support of animations. Three different animated models of traces of recursive functions ranging from concrete to abstract representations were compared. No differences in learning gains were found between the three models in test performance. Three models of animations of applicative operators were compared with students using the replacement modeler and the Scheme interpreter. Significant differences were found favoring animations that addressed causality and salience in their design. Lastly, two binary tree search algorithm animations designed to reduce complexity were compared with hand-tracing of calls. Students made fewer mistakes in predicting the tree traversal when guided by the animations. However, the posttest findings were inconsistent. In summary, animations designed based on the design concerns did not consistently add value to instruction in the form investigated in this research.

Thermal Modeling of the Injection of Standard and Thermally Insulated Cored Wire

NASA Astrophysics Data System (ADS)

Castro-Cedeno, E.-I.; Jardy, A.; Carré, A.; Gerardin, S.; Bellot, J. P.

2017-12-01

Cored wire injection is a widespread method used to perform alloying additions during ferrous and non-ferrous liquid metal treatment. The wire consists of a metal casing that is tightly wrapped around a core of material; the casing delays the release of the material as the wire is immersed into the melt. This method of addition presents advantages such as higher repeatability and yield of cored material with respect to bulk additions. Experimental and numerical work has been performed by several authors on the subject of alloy additions, spherical and cylindrical geometries being mainly considered. Surprisingly this has not been the case for cored wire, where the reported experimental or numerical studies are scarce. This work presents a 1-D finite volume numerical model aimed for the simulation of the thermal phenomena which occurs when the wire is injected into a liquid metal bath. It is currently being used as a design tool for the conception of new types of cored wire. A parametric study on the effect of injection velocity and steel casing thickness for an Al cored wire immersed into a steel melt at 1863 K (1590 °C) is presented. The standard single casing wire is further compared against a wire with multiple casings. Numerical results show that over a certain range of injection velocities, the core contents' release is delayed in the multiple casing when compared to a single casing wire.

Effects of nonuniform Mach-number entrance on scramjet nozzle flowfield and performance

NASA Astrophysics Data System (ADS)

Zhang, Pu; Xu, Jinglei; Quan, Zhibin; Mo, Jianwei

2016-12-01

Considering the non-uniformities of nozzle entrance influenced by the upstream, the effects of nonuniform Mach-number coupled with shock and expansion-wave on the flowfield and performances of single expansion ramp nozzle (SERN) are numerically studied using Reynolds-Averaged Navier-Stokes equations. The adopted Reynolds-averaged Navier-Stokes methodology is validated by comparing the numerical results with the cold experimental data, and the average method used in this paper is discussed. Uniform and nonuniform facility nozzles are designed to generate different Mach-number profile for the inlet of SERN, which is direct-connected with different facility nozzle, and the whole flowfield is simulated. Because of the coupling of shock and expansion-wave, flow direction of nonuniform SERN entrance is distorted. Compared with Mach contour of uniform case, the line is more curved for coupling shock-wave entrance (SWE) case, and flatter for the coupling expansion-wave entrance (EWE) case. Wall pressure distribution of SWE case appears rising region, whereas decreases like stairs of EWE case. The numerical results reveal that the coupled shock and expansion-wave play significant roles on nozzle performances. Compared with the SERN performances of uniform entrance case at the same work conditions, the thrust of nonuniform entrance cases reduces by 3-6%, pitch moment decreases by 2.5-7%. The negative lift presents an incremental trend with EWE while the situation is the opposite with SWE. These results confirm that considering the entrance flow parameter nonuniformities of a scramjet nozzle coupled with shock or expansion-wave from the upstream is necessary.

A comparison of the test-negative and the traditional case-control study designs for estimation of influenza vaccine effectiveness under nonrandom vaccination.

PubMed

Shi, Meng; An, Qian; Ainslie, Kylie E C; Haber, Michael; Orenstein, Walter A

2017-12-08

As annual influenza vaccination is recommended for all U.S. persons aged 6 months or older, it is unethical to conduct randomized clinical trials to estimate influenza vaccine effectiveness (VE). Observational studies are being increasingly used to estimate VE. We developed a probability model for comparing the bias and the precision of VE estimates from two case-control designs: the traditional case-control (TCC) design and the test-negative (TN) design. In both study designs, acute respiratory illness (ARI) patients seeking medical care testing positive for influenza infection are considered cases. In the TN design, ARI patients seeking medical care who test negative serve as controls, while in the TCC design, controls are randomly selected individuals from the community who did not contract an ARI. Our model assigns each study participant a covariate corresponding to the person's health status. The probabilities of vaccination and of contracting influenza and non-influenza ARI depend on health status. Hence, our model allows non-random vaccination and confounding. In addition, the probability of seeking care for ARI may depend on vaccination and health status. We consider two outcomes of interest: symptomatic influenza (SI) and medically-attended influenza (MAI). If vaccination does not affect the probability of non-influenza ARI, then VE estimates from TN studies usually have smaller bias than estimates from TCC studies. We also found that if vaccinated influenza ARI patients are less likely to seek medical care than unvaccinated patients because the vaccine reduces symptoms' severity, then estimates of VE from both types of studies may be severely biased when the outcome of interest is SI. The bias is not present when the outcome of interest is MAI. The TN design produces valid estimates of VE if (a) vaccination does not affect the probabilities of non-influenza ARI and of seeking care against influenza ARI, and (b) the confounding effects resulting from non-random vaccination are similar for influenza and non-influenza ARI. Since the bias of VE estimates depends on the outcome against which the vaccine is supposed to protect, it is important to specify the outcome of interest when evaluating the bias.

Instructional Design: Case Studies in Communities of Practice

ERIC Educational Resources Information Center

Keppell, Michael, Ed.

2007-01-01

"Instructional Design: Case Studies in Communities of Practice" documents real-world experiences of instructional designers and staff developers who work in communities of practice. "Instructional Design: Case Studies in Communities of Practice" explains the strategies and heuristics used by instructional designers when working…

Student reflections following exposure to a case-based interprofessional learning experience: Preliminary findings.

PubMed

Goldberg, Lynette R; Brown, Gina R; Mosack, Victoria A; Fletcher, Phyllis A

2015-01-01

This study analyzed students' written reflections following their initial exposure to interprofessional teamwork in case-based problem-solving. A three-hour seminar featuring three sequenced scenarios was developed and offered 12-times over two semesters. A total of 305 students from a variety of healthcare programs worked together with standardized patients in an on-campus laboratory simulating hospital ward and rehabilitation settings. A thematic analysis of students' reflections showed that they valued the shared learning and realistic case study. However, they felt the experience would be strengthened by working in smaller, more representative teams that included students from medicine, psychology, and social work to enable more effective communication and comprehensive case discussion. While useful for future planning, the identified themes did not enable a comparative statistical analysis of what students found helpful and difficult and a re-coding of students' responses now is underway. Implications for measuring the effectiveness of future interprofessional case-based learning center on addressing the identified weaknesses, and establishing a research design that enables a comparison of pre- and post-seminar data, and the effectiveness of the IPE experience compared to profession-specific experiences.

Evaluating efficiency and statistical power of self-controlled case series and self-controlled risk interval designs in vaccine safety.

PubMed

Li, Rongxia; Stewart, Brock; Weintraub, Eric

2016-01-01

The self-controlled case series (SCCS) and self-controlled risk interval (SCRI) designs have recently become widely used in the field of post-licensure vaccine safety monitoring to detect potential elevated risks of adverse events following vaccinations. The SCRI design can be viewed as a subset of the SCCS method in that a reduced comparison time window is used for the analysis. Compared to the SCCS method, the SCRI design has less statistical power due to fewer events occurring in the shorter control interval. In this study, we derived the asymptotic relative efficiency (ARE) between these two methods to quantify this loss in power in the SCRI design. The equation is formulated as [Formula: see text] (a: control window-length ratio between SCRI and SCCS designs; b: ratio of risk window length and control window length in the SCCS design; and [Formula: see text]: relative risk of exposed window to control window). According to this equation, the relative efficiency declines as the ratio of control-period length between SCRI and SCCS methods decreases, or with an increase in the relative risk [Formula: see text]. We provide an example utilizing data from the Vaccine Safety Datalink (VSD) to study the potential elevated risk of febrile seizure following seasonal influenza vaccine in the 2010-2011 season.

Capsule physics comparison of different ablators for NIF implosion designs

NASA Astrophysics Data System (ADS)

Clark, Daniel; Kritcher, Andrea; Yi, Austin; Zylstra, Alex; Haan, Steven; Ralph, Joseph; Weber, Christopher

2017-10-01

Indirect drive implosion experiments on the Naitonal Ignition Facility (NIF) have now tested three different ablator materials: glow discharge polymer (GDP) plastic, high density carbon (HDC), and beryllium. How do these different ablator choices compare in current and future implosion experiments on NIF? What are the relative advantages and disadvantages of each? This talk compares these different ablator options in capsule-only simulations of current NIF experiments and proposed future designs. The simulations compare the impact of the capsule fill tube, support tent, and interface surface roughness for each case, as well as all perturbations in combination. According to the simulations, each ablator is impacted by the various perturbation sources differently, and each material poses unique challenges in the pursuit of ignition. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Case reports and case series in prehospital emergency care research.

PubMed

Patterson, P Daniel; Weaver, Matthew; Clark, Sunday; Yealy, Donald M

2010-11-01

Research begins with a clearly stated question, problem or hypothesis. The selection of a study design appropriate to the task is the next key step. This paper provides guidance for the use of case report and case series designs by describing the 'what', 'when' and 'how' of both designs. Also described is the use of case reports and case series study designs in prehospital emergency research and the quality of published literature from 2000 to mid-2008.

Correlation of probability scores of placenta accreta on magnetic resonance imaging with hemorrhagic morbidity.

PubMed

Lim, Grace; Horowitz, Jeanne M; Berggruen, Senta; Ernst, Linda M; Linn, Rebecca L; Hewlett, Bradley; Kim, Jennifer; Chalifoux, Laurie A; McCarthy, Robert J

2016-11-01

To evaluate the hypothesis that assigning grades to magnetic resonance imaging (MRI) findings of suspected placenta accreta will correlate with hemorrhagic outcomes. We chose a single-center, retrospective, observational design. Nulliparous or multiparous women who had antenatal placental MRI performed at a tertiary level academic hospital were included. Cases with antenatal placental MRI were included and compared with cases without MRI performed. Two radiologists assigned a probability score for accreta to each study. Estimated blood loss and transfusion requirements were compared among groups by the Kruskal-Wallis H test. Thirty-five cases had placental MRI performed. MRI performance was associated with higher blood loss compared with the non-MRI group (2600 [1400-4500]mL vs 900[600-1500]mL, P<.001). There was no difference in estimated blood loss (P=.31) or transfusion (P=.57) among the MRI probability groups. In cases of suspected placenta accreta, probability scores for antenatal placental MRI may not be associated with increasing degrees of hemorrhage. Continued research is warranted to determine the effectiveness of assigning probability scores for antenatal accreta imaging studies, combined with clinical indices of suspicion, in assisting with antenatal multidisciplinary team planning for operative management of this morbid condition. Copyright © 2016 Elsevier Inc. All rights reserved.

Mycoplasmataceae Colonizations in Women With Urethral Pain Syndrome: A Case-Control Study.

PubMed

Kyndel, Anna; Elmér, Caroline; Källman, Owe; Altman, Daniel

2016-07-01

To determine if Mycoplasma genitalium, Ureaplasma urealyticum, and Ureaplasma parvum are more common in premenopausal women with urethral pain syndrome than in asymptomatic controls. We used a case-control study design to compare the prevalence of M. genitalium, U. urealyticum, and U. parvum using polymerase chain reaction (PCR) analysis in urine. Urethral pain syndrome was defined as localized urethral pain with or without accompanying lower urinary tract symptoms during the past month or longer and at least one negative urine culture. Among the 28 cases, 46% carried Ureaplasma species compared with 64% of the 92 controls overall (P = 0.09). There were no significant differences in the prevalence of U. parvum and U. urealyticum among controls than in patients with urethral pain syndrome (P = 0.35 and P = 0.33, respectively). Co-colonization with U. parvum and urealyticum was infrequent, and there was only one case of M. genitalium colonization, which occurred among the controls. The symptomatic profile of Ureaplasma carriers with urethral pain syndrome was heterogeneous with no clear pattern and did not differ significantly compared with patients negative for Ureaplasma. We found no evidence to support the notion that M. genitalium, U. parvum, and U. urealyticum are more prevalent in women with urethral pain syndrome than in women without lower urinary tract symptoms.

Xenogeneic Collagen Matrix Versus Connective Tissue Graft: Case Series of Various Gingival Recession Treatments.

PubMed

Chevalier, Grégoire; Cherkaoui, Selma; Kruk, Hanna; Bensaïd, Xavier; Danan, Marc

A xenogeneic collagen matrix recently has been suggested as an alternative to connective tissue graft for the treatment of gingival recession. The matrix avoids the second surgical site, and as a consequence could decrease surgical morbidity. This new matrix was used in various clinical situations and compared to connective tissue graft (CTG) in a split-mouth design case series. A total of 17 recessions were treated with a coronally advanced flap, 9 with CTG, and 8 with the matrix. Mean recession reduction was 2.00 mm with the CTG and 2.00 mm with the matrix. No significant statistical differences between the techniques were observed in this case report.

Xenogeneic Collagen Matrix Versus Connective Tissue Graft: Case Series of Various Gingival Recession Treatments.

PubMed

Chevalier, Grégoire; Cherkaoui, Selma; Kruk, Hanna; Bensaïd, Xavier; Danan, Marc

2016-08-24

A xenogeneic collagen matrix recently has been suggested as an alternative to connective tissue graft for the treatment of gingival recession. The matrix avoids the second surgical site, and as a consequence could decrease surgical morbidity. This new matrix was used in various clinical situations and compared to connective tissue graft (CTG) in a split-mouth design case series. A total of 17 recessions were treated with a coronally advanced flap, 9 with CTG, and 8 with the matrix. Mean recession reduction was 2.00 mm with the CTG and 2.00 mm with the matrix. No significant statistical differences between the techniques were observed in this case report.

Experimental Investigation of the Flow Field in a Transonic, Axial Flow Compressor with Respect to the Development of Blockage and Loss

NASA Technical Reports Server (NTRS)

Suder, Kenneth L.

1996-01-01

A detailed experimental investigation to understand and quantify the development of loss and blockage in the flow field of a transonic, axial flow compressor rotor has been undertaken. Detailed laser anemometer measurements were acquired upstream, within, and downstream of a transonic, axial compressor rotor operating at design and off-design conditions. The rotor was operated at 100%, 85%, 80%, and 60% of design speed which provided inlet relative Mach numbers at the blade tip of 1.48, 1.26, 1.18, and 0.89 respectively. At design speed the blockage is evaluated ahead of the rotor passage shock, downstream of the rotor passage shock, and near the trailing edge of the blade row. The blockage is evaluated in the core flow area as well as in the casing endwall region. Similarly at pm speed conditions for the cases of (1) where the rotor passage shock is much weaker than that at design speed and (2) where there is no rotor passage shock, the blockage and loss are evaluated and compared to the results at design speed. Specifically, the impact of the rotor passage shock on the blockage and loss development, pertaining to both the shock/boundary layer interactions and the shock/tip clearance flow interactions, is discussed. In addition, the blockage evaluated from the experimental data is compared to (1) an existing correlation of blockage development which was based on computational results, and (2) computational results on a limited basis. The results indicate that for this rotor the blockage in the endwall region is 2-3 times that of the core flow region and the blockage in the core flow region more than doubles when the shock strength is sufficient to separate the suction surface boundary layer. The distribution of losses in the care flow region indicate that the total loss is primarily comprised of the shock loss when the shock strength is not sufficient to separate the suction surface boundary layer. However, when the shock strength is sufficient to separate the suction surface boundary layer, the profile loss is comparable to the shock loss and can exceed the shock loss.

Learning on the Job: A Situated Account of Teacher Learning in High School Mathematics Departments

ERIC Educational Resources Information Center

Horn, Ilana Seidel

2005-01-01

To investigate teachers' everyday on-the-job learning, I used a comparative case study design and examined the work of mathematics teachers in 2 high schools. Analysis of interviews, classroom observations, and teachers' conversations highlighted 3 key resources for learning: (a) reform artifacts oriented the teachers' attention to key concepts of…

The Effects of Morpheme and Prosody Instruction on Middle School Spelling

ERIC Educational Resources Information Center

Dornay, Margaret A.

2017-01-01

A single case design was used to investigate the impact of two types of instruction on middle school students' spelling. Phase 1 emphasized morphology awareness instruction (MAI) and phase 2 employed the addition of prosody awareness instruction (PAI). In order to compare the effects of MAI and PAI, spelling scores were gathered from eight…

Metrics Matter: How Properties and Perceptions of Data Shape Teachers' Instructional Responses

ERIC Educational Resources Information Center

Farrell, Caitlin C.; Marsh, Julie A.

2016-01-01

Purpose: Supporting teachers' use of data has become a large part of educational leaders' instructional leadership. Drawing on sensemaking theory, we explore how features of data and teachers' perceptions of them may matter when teachers consider student learning data. Design: The article draws on a 1-year, comparative case study of five…

Development of Helicopter Capabilities in the U.S. Army During the Korean and Vietnam Wars

DTIC Science & Technology

2016-06-10

capacity, cost, vulnerability and complexity of design comparing to fixed- wind capability. However, helicopters had their unbeatable advantage... wires , rescuing of downed pilots and casualty 23 Horn, 66. 24 Ibid., 75. 23 evacuation...missions: air transportation, medical evacuation, wire laying, reconnaissance, artillery spotting, messenger service and many others. In case of both

Students' Learning Performance and Transitions in Different Learning Pathways to Higher Vocational Education

ERIC Educational Resources Information Center

Biemans, Harm; Mariën, Hans; Fleur, Erik; Tobi, Hilde; Nieuwenhuis, Loek; Runhaar, Piety

2016-01-01

To improve students' transitions between successive educational levels, continuing learning pathways are being designed and implemented in many countries. This study was carried out to examine the effects of the Green Lycea (GL) as critical cases of continuing learning pathways in vocational education in The Netherlands. The GL were compared with…

A Case Study for Comparing the Effectiveness of a Computer Simulation and a Hands-on Activity on Learning Electric Circuits

ERIC Educational Resources Information Center

Ekmekci, Adem; Gulacar, Ozcan

2015-01-01

Science education reform emphasizes innovative and constructivist views of science teaching and learning that promotes active learning environments, dynamic instructions, and authentic science experiments. Technology-based and hands-on instructional designs are among innovative science teaching and learning methods. Research shows that these two…

Satellite-Distributed Educational Television For Developing Countries; Working Papers. Volume 4.

ERIC Educational Resources Information Center

Schramm, Wilbur; And Others

This volume contains a collection of working papers designed to accompany the case studies of India and Latin America in providing a framework for the planning of educational broadcasting systems. The first two papers offer useful orientation to policy-makers who are considering educational television. Working Paper No. 3 compares the two media of…

The Adoption and Diffusion of eLearning in UK Universities: A Comparative Case Study Using Giddens's Theory of Structuration

ERIC Educational Resources Information Center

Hardaker, Glenn; Singh, Gurmak

2011-01-01

Purpose: This exploratory study seeks to identify the factors that influence the adoption and diffusion of instructional technology at five prominent universities in the UK. The study aims to examine the organisational factors that enable and inhibit organisational adoption and diffusion of innovation. Design/methodology/approach: A qualitative…

Using Peer Collaboration to Support Online Reading, Writing, and Communication: An Empowerment Model for Struggling Readers

ERIC Educational Resources Information Center

Henry, Laurie A.; Castek, Jill; O'Byrne, W. Ian; Zawilinski, Lisa

2012-01-01

This comparative case study investigated the implementation of an empowerment model for struggling readers that utilized the Internet as a context for reading, writing, and communicating in 3 different classroom contexts. Through student-centered techniques, such as flexible grouping and peer teaching, we designed Internet Reciprocal Teaching to…

A Program of Entrepreneurial Education for Economic Development: The Case of Northeast Brazil.

ERIC Educational Resources Information Center

Burke, John Miles

A cross-cultural comparative analysis was made of managerial education programs in the United States and Brazil and, based on the findings, an entrepreneurial education program was designed for underdeveloped Northeast Brazil. Persons were found in this region who could act as entrepreneurs except for a lack of fundamental knowledge and skills;…

What Comes out of Incentivized Collaboration: A Qualitative Analysis of Eight Flemish School Networks

ERIC Educational Resources Information Center

Feys, Ellen; Devos, Geert

2015-01-01

Incentivized collaboration, schools that receive incentives such as public funding or additional resources if they join a network, has become quite popular in Europe and North America (e.g. England, Flanders, United States). We used a comparative case study design to explore why schools would enter such an incentivized network and what role…

Design and Analysis of the Warm-To Suspension Links for Jefferson Lab's 11 Gev/c Super High Momentum Spectrometer

NASA Astrophysics Data System (ADS)

Sun, E.; Brindza, P.; Lassiter, S.; Fowler, M.

2010-04-01

This paper describes design and analysis performed for the warm-to-cold suspension links of the warm iron yoke superconducting quadrupole magnets, and superconducting dipole magnet. The results of investigation of titanium Ti-6Al-4V and Nitronic 50 stainless steel for the suspension links to support the cold mass, preloads, forces due to cryogenic temperature, and imbalanced magnetic forces from misalignments are presented. Allowable stresses at normal-case scenarios and worst-case scenarios, space constraints, and heat leak considerations are discussed. Principles of the ASME Pressure Vessel Code were used to determine allowable stresses. Optimal angles of the suspension links were obtained by calculation and finite element methods. The stress levels of suspension links at multiple scenarios are presented, discussed, and compared with the allowable stresses.

Design with high strength steel: A case of failure and its implications

NASA Astrophysics Data System (ADS)

Rahka, Klaus

1992-10-01

A recent proof test failure of a high strength steel pressure vessel is scrutinized. Apparent deficiencies in the procedures to account for elasto-plastic local strain are indicated for the applicable routine (code) strength calculations. Tentative guidance is given for the use of material tensile fracture strain and its strain state (plane strain) correction in fracture margin estimation. A hypothesis that the calculated local strain is comparable with a gauge length weighted tensile ductility for fracture to initiate at a notch root is given. A discussion about the actual implications of the failure case and the suggested remedy in the light of the ASME Boiler and Pressure Vessel Code section 3 and 8 is presented. Further needs for research and development are delineated. Possible yield and ductility related design limits and their use as material quality indices are discussed.

Hovering Dual-Spin Vehicle Groundwork for Bias Momentum Sizing Validation Experiment

NASA Technical Reports Server (NTRS)

Rothhaar, Paul M.; Moerder, Daniel D.; Lim, Kyong B.

2008-01-01

Angular bias momentum offers significant stability augmentation for hovering flight vehicles. The reliance of the vehicle on thrust vectoring for agility and disturbance rejection is greatly reduced with significant levels of stored angular momentum in the system. A methodical procedure for bias momentum sizing has been developed in previous studies. This current study provides groundwork for experimental validation of that method using an experimental vehicle called the Dual-Spin Test Device, a thrust-levitated platform. Using measured data the vehicle's thrust vectoring units are modeled and a gust environment is designed and characterized. Control design is discussed. Preliminary experimental results of the vehicle constrained to three rotational degrees of freedom are compared to simulation for a case containing no bias momentum to validate the simulation. A simulation of a bias momentum dominant case is presented.

Evaluation of Unified Model Microphysics in High-resolution NWP Simulations Using Polarimetric Radar Observations

NASA Astrophysics Data System (ADS)

Johnson, Marcus; Jung, Youngsun; Dawson, Daniel; Supinie, Timothy; Xue, Ming; Park, Jongsook; Lee, Yong-Hee

2018-07-01

The UK Met Office Unified Model (UM) is employed by many weather forecasting agencies around the globe. This model is designed to run across spatial and time scales and known to produce skillful predictions for large-scale weather systems. However, the model has only recently begun running operationally at horizontal grid spacings of ˜1.5 km [e.g., at the UK Met Office and the Korea Meteorological Administration (KMA)]. As its microphysics scheme was originally designed and tuned for large-scale precipitation systems, we investigate the performance of UM microphysics to determine potential inherent biases or weaknesses. Two rainfall cases from the KMA forecasting system are considered in this study: a Changma (quasi-stationary) front, and Typhoon Sanba (2012). The UM output is compared to polarimetric radar observations in terms of simulated polarimetric radar variables. Results show that the UM generally underpredicts median reflectivity in stratiform rain, producing high reflectivity cores and precipitation gaps between them. This is partially due to the diagnostic rain intercept parameter formulation used in the one-moment microphysics scheme. Model drop size is generally both underand overpredicted compared to observations. UM frozen hydrometeors favor generic ice (crystals and snow) rather than graupel, which is reasonable for Changma and typhoon cases. The model performed best with the typhoon case in terms of simulated precipitation coverage.

NEV supply chain coordination and sustainability considering sales effort and risk aversion under the CVaR criterion

PubMed Central

Xu, Xingzhong

2018-01-01

In a two-echelon new energy vehicle (NEV) supply chain consisting of a risk-neutral manufacturer and a risk-averse retailer, the coordination and sustainability problem is investigated. The risk-averse retailer, who makes sales effort and undertakes the incurred effort cost, decides the order quantity and sales effort level under the Conditional Value-at-Risk (CVaR) criterion. We derive the optimal centralized decisions of a vertically integrated supply chain where the retailer is owned by the manufacturer. Taking such a centralized case as the benchmark, we prove that the subsidy-sharing-based wholesale price (SS-WP) contract fails to coordinate the NEV supply chain under the decentralized case where the retailer makes decisions independently. Then we design a subsidy-sharing-based sales rebate/penalty (SS-SRP) contract and derive the contract parameters to achieve coordination. We evaluate the coordination efficiency of this contract and find that a well-designed SS-SRP contract can promote the NEV sales and lead to a Pareto-improving win-win situation for both the NEV manufacturer and retailer compared to the non-coordination case. A series of numerical experiments are carried out to compare the effects of significant parameters under the SS-WP and SS-SRP contract and provide additional observations and implications, including an indication of the necessary conditions to sustainably maintain the NEV supply chain. PMID:29912926

Comparing Visual and Statistical Analysis in Single-Case Studies Using Published Studies

PubMed Central

Harrington, Magadalena; Velicer, Wayne F.

2015-01-01

Little is known about the extent to which interrupted time-series analysis (ITSA) can be applied to short, single-case study designs and whether those applications produce results consistent with visual analysis (VA). This paper examines the extent to which ITSA can be applied to single-case study designs and compares the results based on two methods: ITSA and VA, using papers published in the Journal of Applied Behavior Analysis in 2010. The study was made possible by the development of software called UnGraph® which facilitates the recovery of raw data from the graphs. ITSA was successfully applied to 94% of the examined graphs with the number of observations ranging from 8 to 136. Moderate to high lag 1 autocorrelations (> .50) were found for 46% of the data series. Effect sizes similar to group-level Cohen’s d were identified based on the tertile distribution. Effects ranging from 0.00 to 0.99 were classified as small, those ranging from 1.00 to 2.49 as medium, and large effect sizes were defined as 2.50 or greater. Comparison of the conclusions from VA and ITSA had a low level of agreement (Kappa = .14, accounting for the agreement expected by chance). The results demonstrate that ITSA can be broadly implemented in applied behavior analysis research. These two methods should be viewed as complimentary and used concurrently. PMID:26609876

Numerical analyses of baseline JT-60SA design concepts with the COREDIV code

NASA Astrophysics Data System (ADS)

Zagórski, R.; Gałązka, K.; Ivanova-Stanik, I.; Stępniewski, W.; Garzotti, L.; Giruzzi, G.; Neu, R.; Romanelli, M.

2017-06-01

JT-60SA reference design scenarios at high (#3) and low (#2) density have been analyzed with the help of the self-consistent COREDIV code. Simulations results for a standard C wall and full W wall have been compared in terms of the influence of impurities, both intrinsic (C, W) and seeded (N, Ar, Ne, Kr), on the radiation losses and plasma parameters. For scenario #3 in a C environment, the regime of detachment on divertor plates can be achieved with N or Ne seeding, whereas for the low density and high power scenario (#2), the C and seeding impurity radiation does not effectively reduce power to the targets. In this case, only an increase of either average density or edge density together with Kr seeding might help to develop conditions with strong radiation losses and semi-detached conditions in the divertor. The calculations show that, in the case of a W divertor, the power load to the plate is mitigated by seeding and the central plasma dilution is smaller compared to the C divertor. For the high density case (#3) with Ne seeding, operation in full detachment mode is predicted. Ar seems to be an optimal choice for the low-density high-power scenario #2, showing a wide operating window, whereas Ne leads to high plasma dilution at high seeding levels albeit not achieving semi-detached conditions in the divertor.

Interpretive Research Aiming at Theory Building: Adopting and Adapting the Case Study Design

ERIC Educational Resources Information Center

Diaz Andrade, Antonio

2009-01-01

Although the advantages of case study design are widely recognised, its original positivist underlying assumptions may mislead interpretive researchers aiming at theory building. The paper discusses the limitations of the case study design for theory building and explains how grounded theory systemic process adds to the case study design. The…

Efficacy and Safety of Gabapentin in the Treatment of Chronic Cough: A Systematic Review.

PubMed

Shi, Guanglin; Shen, Qin; Zhang, Caixin; Ma, Jun; Mohammed, Anaz; Zhao, Huan

2018-06-19

Despite recent clinical guidelines, the optimal therapeutic strategy for the management of refractory chronic cough is still a challenge. The present systematic review was designed to assess the evidence for efficacy and safety of gabapentin in the treatment of chronic cough. A systematic search of PubMed, Embase, Cochrane Library databases, and publications cited in bibliographies was performed. Articles were searched by two reviewers with a priori criteria for study selection. Seven relevant articles were identified, including two randomized controlled trials, one prospective case-series designed with consecutive patients, one retrospective case series of consecutive patients, one retrospective case series with unknown consecutive status, and two case reports comprising six and two patients, respectively. Improvements were detected in cough-specific quality of life (Leicester Cough Questionnaire score) and cough severity (visual analogue scale score) following gabapentin treatment in randomized controlled trials. The results of prospective case-series showed that the rate of overall improvement of cough and sensory neuropathy with gabapentin was 68%. Gabapentin treatment of patients with chronic cough showed superior efficacy and a good safety record compared with placebo or standard medications. Additional randomized and controlled trials are needed. Copyright©2018. The Korean Academy of Tuberculosis and Respiratory Diseases.

Fragrances and work-related asthma-California surveillance data, 1993-2012.

PubMed

Weinberg, Justine Lew; Flattery, Jennifer; Harrison, Robert

2017-12-01

Fragrance chemicals are used in a large array of products. Workers may be exposed to these chemicals in the workplace directly when used as air fresheners, or indirectly in personal care products used by coworkers or others. This study characterizes work-related asthma (WRA) cases associated with fragrance exposures in California workplaces from 1993 through 2012. We used the California Work-Related Asthma Prevention Program's surveillance database to identify individuals with physician-diagnosed WRA associated with the use of air fresheners and scented personal care products (perfumes, colognes, etc.). Cases were classified using previously published, standardized surveillance methods. Perfume was the ninth most common exposure identified from 1993 through 2012. A total of 270 WRA cases associated with fragrance exposure were reported during this period, representing 3.8% of all confirmed cases. These 270 cases included 242 associated with perfume or cologne, 32 associated with air freshener, and 4 associated with both. Similar to non-fragrance cases, nearly a quarter of fragrance-associated cases were classified as new-onset asthma. Fragrance-associated cases were significantly more likely to be in office, health, and education jobs than non-fragrance-associated cases. When compared to non-fragrance cases, fragrance cases were significantly more likely to be female (94% vs 62%) and be classified as having work-aggravated asthma (38% vs 20%), yet had similar outcomes compared with cases associated with other exposures. Our surveillance data show that fragrance use in the workplace is associated with WRA. Prevention methods include employee education, enforced fragrance-free policies, well-designed ventilation systems, and good building maintenance.

Provision of pandemic disease information by health sciences librarians: a multisite comparative case series*†‡§

PubMed Central

Featherstone, Robin M; Boldt, R. Gabriel; Torabi, Nazi; Konrad, Shauna-Lee

2012-01-01

Objective: The research provides an understanding of pandemic information needs and informs professional development initiatives for librarians in disaster medicine. Methods: Utilizing a multisite, comparative case series design, the researchers conducted semi-structured interviews and examined supplementary materials in the form of organizational documents, correspondence, and websites to create a complete picture of each case. The rigor of the case series was ensured through data and investigator triangulation. Interview transcripts were coded using NVivo to identify common themes and points of comparison. Results: Comparison of the four cases revealed a distinct difference between “client-initiated” and “librarian-initiated” provision of pandemic information. Librarian-initiated projects utilized social software to “push” information, whereas client-initiated projects operated within patron-determined parameters to deliver information. Health care administrators were identified as a key audience for pandemic information, and news agencies were utilized as essential information sources. Librarians' skills at evaluating available information proved crucial for selecting best-quality evidence to support administrative decision making. Conclusions: Qualitative analysis resulted in increased understanding of pandemic information needs and identified best practices for disseminating information during periods of high organizational stress caused by an influx of new cases of an unknown infectious disease. PMID:22514506

Long term outcome of neonatal meningitis

PubMed Central

Stevens, J; Eames, M; Kent, A; Halket, S; Holt, D; Harvey, D

2003-01-01

Objectives: To quantify long term impairment after neonatal meningitis. Design: Longitudinal case-control study over 9–10 years. Subjects and methods: A total of 111 children who had suffered neonatal meningitis were seen and compared with 113 matched controls from their birth hospital and 49 controls from general practices. Assessments included the WISC IIIUK , movement assessment battery for children (mABC), audiometry, vision testing, and social and medical data. Statistical analysis was by multiple regression, analysis of variance, and χ2 tests. Results: Some 10.8% of cases had a severe and 9% a moderate overall outcome compared with 0% and 1.8% for the hospital controls. The mean intelligence quotient (IQ) of the cases (88.8) was significantly less than that of the hospital controls (99.4) or the GP controls (99.6) . The mABC score was significantly worse for the cases (7.08) than the hospital (5) or GP (4) controls. Some 3.6% of cases had sensorineural hearing loss, 2.7% had persisting hydrocephalus; no controls did. Some 5.4% of cases and 1.7% of hospital controls had treatment for seizures. Conclusions: Severe neurodisability and milder motor and psychometric impairment result from neonatal meningitis. Both clinical follow up and comprehensive developmental assessment are needed after this disease. PMID:12719389

Initial implementation and evaluation of a Hepatitis C treatment clinical decision support system (CDSS)

PubMed Central

Fathauer, L; Meek, J.

2012-01-01

Background Clinician compliance with clinical guidelines in the treatment of patients with Hepatitis C (HCV) has been reported to be as low as 18.5%. Treatment is complex and patient compliance is often inconsistent thus, active clinician surveillance and support is essential to successful outcomes. A clinical decision support system (CDSS) embedded within an electronic health record can provide reminders, summarize key data, and facilitate coordination of care. To date, the literature is bereft of information describing the implementation and evaluation of a CDSS to support HCV treatment. Objective The purpose of this case report is to describe the design, implementation, and initial evaluation of an HCV-specific CDSS while piloting data collection metrics and methods to be used in a larger study across multiple practices. Methods The case report describes the design and implementation processes with preliminary reporting on impact of the CDSS on quality indicator completion by comparing the pre-CDSS group to the post-CDSS group. Results The CDSS was successfully designed and implemented using an iterative, collaborative process. Pilot testing of the clinical outcomes of the CDSS revealed high rates of quality indicator completion in both the pre- and post-CDSS; although the post-CDSS group received a higher frequency of reminders (4.25 per patient) than the pre-CDSS group (.25 per patient). Conclusions This case report documents the processes used to successfully design and implement an HCV CDSS. While the small sample size precludes generalizability of findings, results did positively demonstrate the feasibility of comparing quality indicator completion rates pre-CDSS and post-CDSS. It is recommended that future studies include a larger sample size across multiple providers with expanded outcomes measures related to patient outcomes, staff satisfaction with the CDSS, and time studies to evaluate efficiency and cost effectiveness of the CDSS. PMID:23646082

Towards a full integration of optimization and validation phases: An analytical-quality-by-design approach.

PubMed

Hubert, C; Houari, S; Rozet, E; Lebrun, P; Hubert, Ph

2015-05-22

When using an analytical method, defining an analytical target profile (ATP) focused on quantitative performance represents a key input, and this will drive the method development process. In this context, two case studies were selected in order to demonstrate the potential of a quality-by-design (QbD) strategy when applied to two specific phases of the method lifecycle: the pre-validation study and the validation step. The first case study focused on the improvement of a liquid chromatography (LC) coupled to mass spectrometry (MS) stability-indicating method by the means of the QbD concept. The design of experiments (DoE) conducted during the optimization step (i.e. determination of the qualitative design space (DS)) was performed a posteriori. Additional experiments were performed in order to simultaneously conduct the pre-validation study to assist in defining the DoE to be conducted during the formal validation step. This predicted protocol was compared to the one used during the formal validation. A second case study based on the LC/MS-MS determination of glucosamine and galactosamine in human plasma was considered in order to illustrate an innovative strategy allowing the QbD methodology to be incorporated during the validation phase. An operational space, defined by the qualitative DS, was considered during the validation process rather than a specific set of working conditions as conventionally performed. Results of all the validation parameters conventionally studied were compared to those obtained with this innovative approach for glucosamine and galactosamine. Using this strategy, qualitative and quantitative information were obtained. Consequently, an analyst using this approach would be able to select with great confidence several working conditions within the operational space rather than a given condition for the routine use of the method. This innovative strategy combines both a learning process and a thorough assessment of the risk involved. Copyright © 2015 Elsevier B.V. All rights reserved.

Up-and-down designs for phase I clinical trials

PubMed Central

Liu, Suyu; Cai, Chunyan; Ning, Jing

2014-01-01

Various up-and-down designs have been proposed to improve the operating characteristics of the traditional “3+3” design, but they have been of limited use in practice. A major impediment to the adoption of the improved up-and-down designs is a lack of general guidance and a comprehensive assessment of the operating characteristics of these designs under practical clinical settings. To fill this gap, we review six up-and-down designs: the “3+3” design, accelerated titration design, biased coin design, k-in-a-row design, group up-and-down design and cumulative group up-and-down design. We conduct comprehensive simulation studies to evaluate their operating characteristics under various practical settings, and compare their performance to a theoretical optimal bound of nonparametric designs. The results show that the cumulative group up-and-down design has the best overall performance in terms of selecting the maximum tolerated dose (MTD), assigning patients to the MTD and patient safety. Its performance is generally close to the upper bound of nonparametric designs, but improvement seems possible in some cases. PMID:23856381

Governmental designation of spine specialty hospitals, their characteristics, performance and designation effects: a longitudinal study in Korea.

PubMed

Kim, Sun Jung; Yoo, Ji Won; Lee, Sang Gyu; Kim, Tae Hyun; Han, Kyu-Tae; Park, Eun-Cheol

2014-11-13

This study compares the characteristics and performance of spine specialty hospitals versus other types of hospitals for inpatients with spinal diseases in South Korea. We also assessed the effect of the government's specialty hospital designation on hospital operating efficiency. We used data of 823 hospitals including 17 spine specialty hospitals in Korea. All spine disease-related inpatient claims nationwide (N=645 449) during 2010-2012. No interventions were made. Using a multilevel generalised estimating equation and multilevel modelling, this study compared inpatient charges, length of stay (LOS), readmission within 30 days of discharge and in-hospital death within 30 days of admission in spine specialty versus other types of hospitals. Spine specialty hospitals had higher inpatient charges per day (27.4%) and a shorter LOS (23.5%), but per case charges were similar after adjusting for patient-level and hospital-level confounders. After government designation, spine specialty hospitals had 8.8% lower per case charges, which was derived by reduced per day charge (7.6%) and shorter LOS (1.0%). Rates of readmission also were lower in spine specialty hospitals (OR=0.796). Patient-level and hospital-level factors both played important roles in determining outcome measures. Spine specialty hospitals had higher per day inpatient charges but a much shorter LOS than other types of hospitals due to their specialty volume and experience. In addition, their readmission rate was lower. Spine specialty hospitals also endeavoured to be more efficient after governmental 'specialty' designation. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

The deflection of circular mirrors of linearly varying thickness supported along a central hole and free along the outer edge.

PubMed

Prevenslik, T V

1968-10-01

Most cassegrainian mirrors supported along the central hole are designed for deflection tolerances using the theory for solid, constant thickness plates. Where tolerances are critical, the mirror is usually made thicker, thereby reducing the deflection, but also increasing the weight of the mirror. Weight can be reduced by using a honeycomb design; however, manufacturing problems result because of the inherent complexity. To circumvent the disadvantages of excessive weight in the solid, constant thickness design and the complexity of the honeycomb design, a lightweight, yet simple design would be desirable. A possible lightweight, yet simple design would be a solid mirror of linearly varying thickness, decreasing in thickness from the center to the outer edge. As mirrors of linearly varying thickness may provide the best solution under combined deflection and weight restraints, a design basis is required and found in small deflection plate theory. The work of H. Conway was extended to account for pressure loading proportional to mirror density for the case when Poisson's ratio is ?. Closed form solutions for the slope of the linearly varying thickness mirrors were obtained for fixed and simply supported boundary conditions along the central hole. Maximum deflections were obtained by numerical integration and compared with the results for comparable constant thickness mirrors.

Composite Structure Modeling and Analysis of Advanced Aircraft Fuselage Concepts

NASA Technical Reports Server (NTRS)

Mukhopadhyay, Vivek; Sorokach, Michael R.

2015-01-01

NASA Environmentally Responsible Aviation (ERA) project and the Boeing Company are collabrating to advance the unitized damage arresting composite airframe technology with application to the Hybrid-Wing-Body (HWB) aircraft. The testing of a HWB fuselage section with Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) construction is presently being conducted at NASA Langley. Based on lessons learned from previous HWB structural design studies, improved finite-element models (FEM) of the HWB multi-bay and bulkhead assembly are developed to evaluate the performance of the PRSEUS construction. In order to assess the comparative weight reduction benefits of the PRSEUS technology, conventional cylindrical skin-stringer-frame models of a cylindrical and a double-bubble section fuselage concepts are developed. Stress analysis with design cabin-pressure load and scenario based case studies are conducted for design improvement in each case. Alternate analysis with stitched composite hat-stringers and C-frames are also presented, in addition to the foam-core sandwich frame and pultruded rod-stringer construction. The FEM structural stress, strain and weights are computed and compared for relative weight/strength benefit assessment. The structural analysis and specific weight comparison of these stitched composite advanced aircraft fuselage concepts demonstrated that the pressurized HWB fuselage section assembly can be structurally as efficient as the conventional cylindrical fuselage section with composite stringer-frame and PRSEUS construction, and significantly better than the conventional aluminum construction and the double-bubble section concept.

Graduate Students in a Service Learning Design Case: The Development of a Parenting Program

ERIC Educational Resources Information Center

Tracey, Monica W.; Kacin, Sara E.

2014-01-01

The following design case illustrates the approach a group of advanced graduate online-design students, two design coaches, and an instructor used to design an online instructional intervention as a service-learning project for parents interested in improving their parenting skills with their pre-teens. This design case is distinctive in that it…

Design of a Low Aspect Ratio Transonic Compressor Stage Using CFD Techniques

NASA Technical Reports Server (NTRS)

Sanger, Nelson L.

1994-01-01

A transonic compressor stage has been designed for the Naval Postgraduate School Turbopropulsion Laboratory. The design relied heavily on CFD techniques while minimizing conventional empirical design methods. The low aspect ratio (1.2) rotor has been designed for a specific head ratio of .25 and a tip relative inlet Mach number of 1.3. Overall stage pressure ratio is 1.56. The rotor was designed using an Euler code augmented by a distributed body force model to account for viscous effects. This provided a relatively quick-running design tool, and was used for both rotor and stator calculations. The initial stator sections were sized using a compressible, cascade panel code. In addition to being used as a case study for teaching purposes, the compressor stage will be used as a research stage. Detailed measurements, including non-intrusive LDV, will be compared with the design computations, and with the results of other CFD codes, as a means of assessing and improving the computational codes as design tools.

Remote Services, Inc.

ERIC Educational Resources Information Center

Morris, Steven A.

2008-01-01

The Remote Services, Inc. (RSI) case is designed as an extensible, database design and implementation project. The case is designed in two primary components: design and implementation. The design component of the case allows students to evaluate a scenario that is similar to a real-world business situation and create an appropriate design…

Theory-based and evidence-based design of audit and feedback programmes: examples from two clinical intervention studies.

PubMed

Hysong, Sylvia J; Kell, Harrison J; Petersen, Laura A; Campbell, Bryan A; Trautner, Barbara W

2017-04-01

Audit and feedback (A&F) is a common intervention used to change healthcare provider behaviour and, thus, improve healthcare quality. Although A&F can be effective its effectiveness varies, often due to the details of how A&F interventions are implemented. Some have suggested that a suitable conceptual framework is needed to organise the elements of A&F and also explain any observed differences in effectiveness. Through two examples from applied research studies, this article demonstrates how a suitable explanatory theory (in this case Kluger & DeNisi's Feedback Intervention Theory (FIT)) can be systematically applied to design better feedback interventions in healthcare settings. Case 1: this study's objective was to reduce inappropriate diagnosis of catheter-associated urinary tract infections (CAUTI) in inpatient wards. Learning to identify the correct clinical course of action from the case details was central to this study; consequently, the feedback intervention featured feedback elements that FIT predicts would best activate learning processes (framing feedback in terms of group performance and providing of correct solution information). We designed a highly personalised, interactive, one-on-one intervention with healthcare providers to improve their capacity to distinguish between CAUTI and asymptomatic bacteruria (ASB) and treat ASB appropriately. Case 2: Simplicity and scalability drove this study's intervention design, employing elements that FIT predicted positively impacted effectiveness yet still facilitated deployment and scalability (eg, delivered via computer, delivered in writing). We designed a web-based, report-style feedback intervention to help primary care physicians improve their care of patients with hypertension. Both studies exhibited significant improvements in their desired outcome and in both cases interventions were received positively by feedback recipients. A&F has been a popular, yet inconsistently implemented and variably effective tool for changing healthcare provider behaviour and, improving healthcare quality. Through the systematic use of theory such as FIT, robust feedback interventions can be designed that yield greater effectiveness. Future work should look to comparative effectiveness of specific design elements and contextual factors that identify A&F as the optimal intervention to effectuate healthcare provider behaviour change. NCT01052545, NCT00302718; post-results. 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/.

Dengue Outbreak in Hadramout, Yemen, 2010: An Epidemiological Perspective

PubMed Central

Ghouth, Abdulla Salim Bin; Amarasinghe, Ananda; Letson, G. William

2012-01-01

We analyzed surveillance data of a dengue outbreak (2010) reported to the Hadramout Health Office (Yemen) and retrospectively analyzed dengue-related epidemiological and entomological events reported in Hadramout from 2005 to 2009. A total of 630 immunoglobulin M (IgM) -confirmed dengue cases of 982 febrile cases was reported during the period from February to June of 2010; 12 cases died, giving case fatality a rate of 1.9%. Among febrile cases, the highest proportion of dengue cases (37.3%) was reported in the 15- to 24-year-old age group. The overall attack rate was 0.89/1,000. The average number of cases reported by month over the preceding 5-year period compared with the 2010 data is consistent with endemicity of dengue in the region and supports epidemic designation for the dengue activity in 2010. Recognition of endemic dengue transmission and potential for substantial dengue epidemics highlight the need for consistent laboratory-based surveillance that can support prevention and control activities accordingly. PMID:22665621

[Diversity and frequency of scientific research design and statistical methods in the "Arquivos Brasileiros de Oftalmologia": a systematic review of the "Arquivos Brasileiros de Oftalmologia"--1993-2002].

PubMed

Crosta, Fernando; Nishiwaki-Dantas, Maria Cristina; Silvino, Wilmar; Dantas, Paulo Elias Correa

2005-01-01

To verify the frequency of study design, applied statistical analysis and approval by institutional review offices (Ethics Committee) of articles published in the "Arquivos Brasileiros de Oftalmologia" during a 10-year interval, with later comparative and critical analysis by some of the main international journals in the field of Ophthalmology. Systematic review without metanalysis was performed. Scientific papers published in the "Arquivos Brasileiros de Oftalmologia" between January 1993 and December 2002 were reviewed by two independent reviewers and classified according to the applied study design, statistical analysis and approval by the institutional review offices. To categorize those variables, a descriptive statistical analysis was used. After applying inclusion and exclusion criteria, 584 articles for evaluation of statistical analysis and, 725 articles for evaluation of study design were reviewed. Contingency table (23.10%) was the most frequently applied statistical method, followed by non-parametric tests (18.19%), Student's t test (12.65%), central tendency measures (10.60%) and analysis of variance (9.81%). Of 584 reviewed articles, 291 (49.82%) presented no statistical analysis. Observational case series (26.48%) was the most frequently used type of study design, followed by interventional case series (18.48%), observational case description (13.37%), non-random clinical study (8.96%) and experimental study (8.55%). We found a higher frequency of observational clinical studies, lack of statistical analysis in almost half of the published papers. Increase in studies with approval by institutional review Ethics Committee was noted since it became mandatory in 1996.

Using public control genotype data to increase power and decrease cost of case-control genetic association studies.

PubMed

Ho, Lindsey A; Lange, Ethan M

2010-12-01

Genome-wide association (GWA) studies are a powerful approach for identifying novel genetic risk factors associated with human disease. A GWA study typically requires the inclusion of thousands of samples to have sufficient statistical power to detect single nucleotide polymorphisms that are associated with only modest increases in risk of disease given the heavy burden of a multiple test correction that is necessary to maintain valid statistical tests. Low statistical power and the high financial cost of performing a GWA study remains prohibitive for many scientific investigators anxious to perform such a study using their own samples. A number of remedies have been suggested to increase statistical power and decrease cost, including the utilization of free publicly available genotype data and multi-stage genotyping designs. Herein, we compare the statistical power and relative costs of alternative association study designs that use cases and screened controls to study designs that are based only on, or additionally include, free public control genotype data. We describe a novel replication-based two-stage study design, which uses free public control genotype data in the first stage and follow-up genotype data on case-matched controls in the second stage that preserves many of the advantages inherent when using only an epidemiologically matched set of controls. Specifically, we show that our proposed two-stage design can substantially increase statistical power and decrease cost of performing a GWA study while controlling the type-I error rate that can be inflated when using public controls due to differences in ancestry and batch genotype effects.

A case control study: White-collar defendants compared with defendants charged with other nonviolent theft.

PubMed

Poortinga, Ernest; Lemmen, Craig; Jibson, Michael D

2006-01-01

We examined the clinical, criminal, and sociodemographic characteristics of all white-collar crime defendants referred to the evaluation unit of a state center for forensic psychiatry. With 29,310 evaluations in a 12-year period, we found 70 defendants charged with embezzlement, 3 with health care fraud, and no other white-collar defendants (based on the eight crimes widely accepted as white-collar offenses). In a case-control study design, the 70 embezzlement cases were compared with 73 defendants charged with other forms of nonviolent theft. White-collar defendants were found to have a higher likelihood of white race (adjusted odds ratio (adj. OR) = 4.51), more years of education (adj. OR = 3471), and a lower likelihood of substance abuse (adj. OR = .28) than control defendants. Logistic regression modeling showed that the variance in the relationship between unipolar depression and white-collar crime was more economically accounted for by education, race, and substance abuse.

Study on a new design of Tehran Research Reactor for radionuclide production based on fast neutrons using MCNPX code.

PubMed

Zandi, Nadia; Afarideh, Hossein; Aboudzadeh, Mohammad Reza; Rajabifar, Saeed

2018-02-01

The aim of this work is to increase the magnitude of the fast neutron flux inside the flux trap where radionuclides are produced. For this purpose, three new designs of the flux trap are proposed and the obtained fast and thermal neutron fluxes compared with each other. The first and second proposed designs were a sealed cube contained air and D 2 O, respectively. The results of calculated production yield all indicated the superiority of the latter by a factor of 55% in comparison to the first proposed design. The third proposed design was based on changing the surrounding of the sealed cube by locating two fuel plates near that. In this case, the production yield increased up to 70%. Copyright © 2017. Published by Elsevier Ltd.

Application of variable-gain output feedback for high-alpha control

NASA Technical Reports Server (NTRS)

Ostroff, Aaron J.

1990-01-01

A variable-gain, optimal, discrete, output feedback design approach that is applied to a nonlinear flight regime is described. The flight regime covers a wide angle-of-attack range that includes stall and post stall. The paper includes brief descriptions of the variable-gain formulation, the discrete-control structure and flight equations used to apply the design approach, and the high performance airplane model used in the application. Both linear and nonlinear analysis are shown for a longitudinal four-model design case with angles of attack of 5, 15, 35, and 60 deg. Linear and nonlinear simulations are compared for a single-point longitudinal design at 60 deg angle of attack. Nonlinear simulations for the four-model, multi-mode, variable-gain design include a longitudinal pitch-up and pitch-down maneuver and high angle-of-attack regulation during a lateral maneuver.

Long-term healthcare cost reduction with Intensive Short-term Dynamic Psychotherapy in a tertiary psychiatric service.

PubMed

Abbass, Allan; Kisely, Steve; Rasic, Daniel; Town, Joel M; Johansson, Robert

2015-05-01

To evaluate whether a mixed population of patients treated with Intensive Short-term Dynamic Psychotherapy (ISTDP) would exhibit reduced healthcare costs in long-term follow-up. A quasi-experimental design was employed in which data on pre- and post-treatment healthcare cost were compared for all ISTDP cases treated in a tertiary care service over a nine year period. Observed cost changes were compared with those of a control group of patients referred but never treated. Physician and hospital costs were compared to treatment cost estimates and normal population cost figures. 1082 patients were included; 890 treated cases for a broad range of somatic and psychiatric disorders and 192 controls. The treatment averaged 7.3 sessions and measures of symptoms and interpersonal problems significantly improved. The average cost reduction per treated case was $12,628 over 3 follow-up years: this compared favorably with the estimated treatment cost of $708 per patient. Significant differences were seen between groups for follow-up hospital costs. ISTDP in this setting appears to facilitate reductions in healthcare costs, supporting the notion that brief dynamic psychotherapy provided in a tertiary setting can be beneficial to health care systems overall. CLINICALTRIALS. NCT01924715. Copyright © 2015 Elsevier Ltd. All rights reserved.

Comparison of fasciocutaneous V-Y and rotational flaps for defect coverage of sacral pressure sores: a critical single-centre appraisal.

PubMed

Djedovic, Gabriel; Metzler, Julia; Morandi, Evi M; Wachter, Tanja; Kühn, Shafreena; Pierer, Gerhard; Rieger, Ulrich M

2017-12-01

Pressure sore rates remain high in both nursing homes as well as in hospitals. Numerous surgical options are available for defect coverage in the sacral region. However, objective data is scarce as to whether a specific flap design is superior to another. Here, we aim to compare two fasciocutaneous flap designs for sacral defect coverage: the gluteal rotation flap and the gluteal V-Y flap. All primary sacral pressure sores of grades III-IV that were being covered with gluteal fasciocutaneous rotational or V-Y flaps between January 2008 and December 2014 at our institution were analysed. A total of 41 patients received a total of 52 flaps. Of these, 18 patients received 20 gluteal rotational flaps, and 23 patients received 32 V-Y flaps. Both groups were comparable with regards to demographics, comorbidities and complications. Significantly more V-Y flaps were needed to cover smaller defects. Mean length of hospital stay was significantly prolonged when surgical revision had to be carried out. Both flap designs have proven safe and reliable for defect coverage after sacral pressure sores. Gluteal rotational flaps appear to be more useful for larger defects. Both flap designs facilitate their reuse in case of pressure sore recurrence. Complication rates appear to be comparable in both designs and to the current literature. © 2017 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

Leveraging prior quantitative knowledge in guiding pediatric drug development: a case study.

PubMed

Jadhav, Pravin R; Zhang, Jialu; Gobburu, Jogarao V S

2009-01-01

The manuscript presents the FDA's focus on leveraging prior knowledge in designing informative pediatric trial through this case study. In developing written request for Drug X, an anti-hypertensive for immediate blood pressure (BP) control, the sponsor and FDA conducted clinical trial simulations (CTS) to design trial with proper sample size and support the choice of dose range. The objective was to effectively use prior knowledge from adult patients for drug X, pediatric data from Corlopam (approved for a similar indication) trial and general experience in developing anti-hypertensive agents. Different scenarios governing the exposure response relationship in the pediatric population were simulated to perturb model assumptions. The choice of scenarios was based on the past observation that pediatric population is less responsive and sensitive compared with adults. The conceptual framework presented here should serve as an example on how the industry and FDA scientists can collaborate in designing the pediatric exclusivity trial. Using CTS, inter-disciplinary scientists with the sponsor and FDA can objectively discuss the choice of dose range, sample size, endpoints and other design elements. These efforts are believed to yield plausible trial design, qrational dosing recommendations and useful labeling information in pediatrics. Published in 2009 by John Wiley & Sons, Ltd.

Detecting well casing leaks in Bangladesh using a salt spiking method

USGS Publications Warehouse

Stahl, M.O.; Ong, J.B.; Harvey, C.F.; Johnson, C.D.; Badruzzaman, A.B.M.; Tarek, M.H.; VanGeen, A.; Anderson, J.A.; Lane, J.W.

2014-01-01

We apply fluid-replacement logging in arsenic-contaminated regions of Bangladesh using a low-cost, down-well fluid conductivity logging tool to detect leaks in the cased section of wells. The fluid-conductivity tool is designed for the developing world: it is lightweight and easily transportable, operable by one person, and can be built for minimal cost. The fluid-replacement test identifies leaking casing by comparison of fluid conductivity logs collected before and after spiking the wellbore with a sodium chloride tracer. Here, we present results of fluid-replacement logging tests from both leaking and non-leaking casing from wells in Araihazar and Munshiganj, Bangladesh, and demonstrate that the low-cost tool produces measurements comparable to those obtained with a standard geophysical logging tool. Finally, we suggest well testing procedures and approaches for preventing casing leaks in Bangladesh and other developing countries.

Detecting well casing leaks in Bangladesh using a salt spiking method.

PubMed

Stahl, M O; Ong, J B; Harvey, C F; Johnson, C D; Badruzzaman, A B M; Tarek, M H; van Geen, A; Anderson, J A; Lane, J W

2014-09-01

We apply fluid-replacement logging in arsenic-contaminated regions of Bangladesh using a low-cost, down-well fluid conductivity logging tool to detect leaks in the cased section of wells. The fluid-conductivity tool is designed for the developing world: it is lightweight and easily transportable, operable by one person, and can be built for minimal cost. The fluid-replacement test identifies leaking casing by comparison of fluid conductivity logs collected before and after spiking the wellbore with a sodium chloride tracer. Here, we present results of fluid-replacement logging tests from both leaking and non-leaking casing from wells in Araihazar and Munshiganj, Bangladesh, and demonstrate that the low-cost tool produces measurements comparable to those obtained with a standard geophysical logging tool. Finally, we suggest well testing procedures and approaches for preventing casing leaks in Bangladesh and other developing countries. © 2014, National Ground Water Association.

Reducing errors from the electronic transcription of data collected on paper forms: a research data case study.

PubMed

Wahi, Monika M; Parks, David V; Skeate, Robert C; Goldin, Steven B

2008-01-01

We conducted a reliability study comparing single data entry (SE) into a Microsoft Excel spreadsheet to entry using the existing forms (EF) feature of the Teleforms software system, in which optical character recognition is used to capture data off of paper forms designed in non-Teleforms software programs. We compared the transcription of data from multiple paper forms from over 100 research participants representing almost 20,000 data entry fields. Error rates for SE were significantly lower than those for EF, so we chose SE for data entry in our study. Data transcription strategies from paper to electronic format should be chosen based on evidence from formal evaluations, and their design should be contemplated during the paper forms development stage.

Reducing Errors from the Electronic Transcription of Data Collected on Paper Forms: A Research Data Case Study

PubMed Central

Wahi, Monika M.; Parks, David V.; Skeate, Robert C.; Goldin, Steven B.

2008-01-01

We conducted a reliability study comparing single data entry (SE) into a Microsoft Excel spreadsheet to entry using the existing forms (EF) feature of the Teleforms software system, in which optical character recognition is used to capture data off of paper forms designed in non-Teleforms software programs. We compared the transcription of data from multiple paper forms from over 100 research participants representing almost 20,000 data entry fields. Error rates for SE were significantly lower than those for EF, so we chose SE for data entry in our study. Data transcription strategies from paper to electronic format should be chosen based on evidence from formal evaluations, and their design should be contemplated during the paper forms development stage. PMID:18308994

Automation of POST Cases via External Optimizer and "Artificial p2" Calculation

NASA Technical Reports Server (NTRS)

Dees, Patrick D.; Zwack, Mathew R.; Michelson, Diane K.

2017-01-01

During conceptual design speed and accuracy are often at odds. Specifically in the realm of launch vehicles, optimizing the ascent trajectory requires a larger pool of analytical power and expertise. Experienced analysts working on familiar vehicles can produce optimal trajectories in a short time frame, however whenever either "experienced" or "familiar " is not applicable the optimization process can become quite lengthy. In order to construct a vehicle agnostic method an established global optimization algorithm is needed. In this work the authors develop an "artificial" error term to map arbitrary control vectors to non-zero error by which a global method can operate. Two global methods are compared alongside Design of Experiments and random sampling and are shown to produce comparable results to analysis done by a human expert.

Designing a Facebook interface for senior users.

PubMed

Gomes, Gonçalo; Duarte, Carlos; Coelho, José; Matos, Eduardo

2014-01-01

The adoption of social networks by older adults has increased in recent years. However, many still cannot make use of social networks as these are simply not adapted to them. Through a series of direct observations, interviews, and focus groups, we identified recommendations for the design of social networks targeting seniors. Based on these, we developed a prototype for tablet devices, supporting sharing and viewing Facebook content. We then conducted a user study comparing our prototype with Facebook's native mobile application. We have found that Facebook's native application does not meet senior users concerns, like privacy and family focus, while our prototype, designed in accordance with the collected recommendations, supported relevant use cases in a usable and accessible manner.

Contribution to the optimal shape design of two-dimensional internal flows with embedded shocks

NASA Technical Reports Server (NTRS)

Iollo, Angelo; Salas, Manuel D.

1995-01-01

We explore the practicability of optimal shape design for flows modeled by the Euler equations. We define a functional whose minimum represents the optimality condition. The gradient of the functional with respect to the geometry is calculated with the Lagrange multipliers, which are determined by solving a co-state equation. The optimization problem is then examined by comparing the performance of several gradient-based optimization algorithms. In this formulation, the flow field can be computed to an arbitrary order of accuracy. Finally, some results for internal flows with embedded shocks are presented, including a case for which the solution to the inverse problem does not belong to the design space.

Intelligent design of permanent magnet synchronous motor based on CBR

NASA Astrophysics Data System (ADS)

Li, Cong; Fan, Beibei

2018-05-01

Aiming at many problems in the design process of Permanent magnet synchronous motor (PMSM), such as the complexity of design process, the over reliance on designers' experience and the lack of accumulation and inheritance of design knowledge, a design method of PMSM Based on CBR is proposed in order to solve those problems. In this paper, case-based reasoning (CBR) methods of cases similarity calculation is proposed for reasoning suitable initial scheme. This method could help designers, by referencing previous design cases, to make a conceptual PMSM solution quickly. The case retain process gives the system self-enrich function which will improve the design ability of the system with the continuous use of the system.

Designing payment for Collaborative Care for Depression in primary care.

PubMed

Bao, Yuhua; Casalino, Lawrence P; Ettner, Susan L; Bruce, Martha L; Solberg, Leif I; Unützer, Jürgen

2011-10-01

To design a bundled case rate for Collaborative Care for Depression (CCD) that aligns incentives with evidence-based depression care in primary care. A clinical information system used by all care managers in a randomized controlled trial of CCD for older primary care patients. We conducted an empirical investigation of factors accounting for variation in CCD resource use over time and across patients. CCD resource use at the patient-episode and patient-month levels was measured by number of care manager contacts and direct patient contact time and analyzed with count data (Poisson or negative binomial) models. Episode-level resource use varies substantially with patient's time in the program. Monthly use declines sharply in the first 6 months regardless of treatment response or remission status, but it remains stable afterwards. An adjusted episode or monthly case rate design better matches payment with variation in resource use compared with a fixed design. Our findings lend support to an episode payment adjusted by number of months receiving CCD and a monthly payment adjusted by the ordinal month. Nonpayment tools including program certification and performance evaluation and reward systems are needed to fully align incentives. © Health Research and Educational Trust.

Computational analysis of hypersonic flows past elliptic-cone waveriders

NASA Technical Reports Server (NTRS)

Yoon, Bok-Hyun; Rasmussen, Maurice L.

1991-01-01

A comprehensive study for the inviscid numerical calculation of the hypersonic flow past a class of elliptic-cone derived waveriders is presented. The theoretical background associated with hypersonic small-disturbance theory (HSDT) is reviewed. Several approximation formulas for the waverider compression surface are established. A CFD algorithm is used to calculate flow fields for the on-design case and a variety of off-design cases. The results are compared with HSDT, experiment, and other available CFD results. For the waverider shape used in previous investigations, the bow shock for the on-design condition stands off from the leading-edge tip of the waverider. It was found that this occurs because the tip was too thick according to the approximating shape formula that was used to describe the compression surface. When this was corrected, the bow shock became closer to attached as it should be. At Mach numbers greater than the design condition, a lambda-shock configuration develops near the tip of the compression surface. At negative angles of attack, other complicated shock patterns occur near the leading-edge tip. These heretofore unknown flow patterns show the power and utility of CFD for investigating novel hypersonic configurations such as waveriders.

Basis of the tubesheet heat exchanger design rules used in the French pressure vessel code

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

Osweiller, F.

1992-02-01

For about 40 years most tubessheet exchangers have been designed according to the standards of TEMA. Partly due to their simplicity, these rules do not assure a safe heat-exchanger design in all cases. This is the main reason why new tubesheet design rules were developed in 1981 in France for the French pressure vessel code CODAP. For fixed tubesheet heat exchangers, the new rules account for the elastic rotational restraint of the shell and channel at the outer edge of the tubesheet, as proposed in 1959 by Galletly. For floating-head and U-tube heat exchangers, the approach developed by Gardner inmore » 1969 was selected with some modifications. In both cases, the tubesheet is replaced by an equivalent solid plate with adequate effective elastic constants, and the tube bundle is simulated by an elastic foundation. The elastic restraint at the edge of the tubesheet due the shell and channel is accounted for in different ways in the two types of heat exchangers. The purpose of the paper is to present the main basis of these rules and to compare them to TEMA rules.« less

Fetal omphalocele ratios predict outcomes in prenatally diagnosed omphalocele.

PubMed

Montero, Freddy J; Simpson, Lynn L; Brady, Paula C; Miller, Russell S

2011-09-01

The objective of the study was to evaluate whether ratios considering omphalocele diameter relative to fetal biometric measurements perform better than giant omphalocele designation at predicting inability to achieve neonatal primary surgical closure. Cases of fetal omphalocele that underwent evaluation between May 2003 and July 2010 were identified. Inclusion was restricted to live births with plan for postnatal repair. Omphalocele diameter upon antenatal ultrasound was compared with abdominal circumference, femur length, and head circumference, yielding the respective omphalocele (O)/abdominal circumference (AC), O/femur length (FL), and O/head circumference (HC) ratios. The absolute measurements were used to classify giant lesions. Omphalocele ratios and giant omphalocele designations were evaluated as predictors of inability to achieve primary repair. Among 25 included cases, staged or delayed closure occurred in 52%. With an optimal cutoff of 0.21 or greater, O/HC best predicted the primary outcome (sensitivity, 84.6%; specificity, 58.3%; odds ratio, 7.7). The O/HC of 0.21 or greater outperformed giant designations. The O/HC of 0.21 or greater best predicted staged or delayed omphalocele closure. Giant omphalocele designation, regardless of definition, poorly predicted outcome. Copyright © 2011 Mosby, Inc. All rights reserved.

WeSaySo Case Study: Designing and Implementing a Case Study for Use in an Instructional Design Class.

ERIC Educational Resources Information Center

Graves, Rick; Barnett, Mardee; Gamble, Yolanda; Kolak, Mike

A case study was used in an instructional design class to facilitate the transfer of conceptual knowledge to concrete concerns and to aid instructional technology graduate students' understanding of the steps involved in designing, analyzing, and implementing an effective needs analysis. The case study involved real events at fictitious company…

Comparing Dynamic Treatment Regimes Using Repeated-Measures Outcomes: Modeling Considerations in SMART Studies

PubMed Central

Lu, Xi; Nahum-Shani, Inbal; Kasari, Connie; Lynch, Kevin G.; Oslin, David W.; Pelham, William E.; Fabiano, Gregory; Almirall, Daniel

2016-01-01

A dynamic treatment regime (DTR) is a sequence of decision rules, each of which recommends a treatment based on a patient’s past and current health status. Sequential, multiple assignment, randomized trials (SMARTs) are multi-stage trial designs that yield data specifically for building effective DTRs. Modeling the marginal mean trajectories of a repeated-measures outcome arising from a SMART presents challenges, because traditional longitudinal models used for randomized clinical trials do not take into account the unique design features of SMART. We discuss modeling considerations for various forms of SMART designs, emphasizing the importance of considering the timing of repeated measures in relation to the treatment stages in a SMART. For illustration, we use data from three SMART case studies with increasing level of complexity, in autism, child attention deficit hyperactivity disorder (ADHD), and adult alcoholism. In all three SMARTs we illustrate how to accommodate the design features along with the timing of the repeated measures when comparing DTRs based on mean trajectories of the repeated-measures outcome. PMID:26638988

Comparing dynamic treatment regimes using repeated-measures outcomes: modeling considerations in SMART studies.

PubMed

Lu, Xi; Nahum-Shani, Inbal; Kasari, Connie; Lynch, Kevin G; Oslin, David W; Pelham, William E; Fabiano, Gregory; Almirall, Daniel

2016-05-10

A dynamic treatment regime (DTR) is a sequence of decision rules, each of which recommends a treatment based on a patient's past and current health status. Sequential, multiple assignment, randomized trials (SMARTs) are multi-stage trial designs that yield data specifically for building effective DTRs. Modeling the marginal mean trajectories of a repeated-measures outcome arising from a SMART presents challenges, because traditional longitudinal models used for randomized clinical trials do not take into account the unique design features of SMART. We discuss modeling considerations for various forms of SMART designs, emphasizing the importance of considering the timing of repeated measures in relation to the treatment stages in a SMART. For illustration, we use data from three SMART case studies with increasing level of complexity, in autism, child attention deficit hyperactivity disorder, and adult alcoholism. In all three SMARTs, we illustrate how to accommodate the design features along with the timing of the repeated measures when comparing DTRs based on mean trajectories of the repeated-measures outcome. Copyright © 2015 John Wiley & Sons, Ltd.

Health and Economic Burden of Post-Partum Staphylococcus aureus Breast Abscess

PubMed Central

Branch-Elliman, Westyn; Lee, Grace M.; Golen, Toni H.; Gold, Howard S.; Baldini, Linda M.; Wright, Sharon B.

2013-01-01

Objectives To determine the health and economic burdens of post-partum Staphylococcus aureus breast abscess. Study design We conducted a matched cohort study (N = 216) in a population of pregnant women (N = 32,770) who delivered at our center during the study period from 10/1/03–9/30/10. Data were extracted from hospital databases, or via chart review if unavailable electronically. We compared cases of S. aureus breast abscess to controls matched by delivery date to compare health services utilization and mean attributable medical costs in 2012 United States dollars using Medicare and hospital-based estimates. We also evaluated whether resource utilization and health care costs differed between cases with methicillin-resistant and -susceptible S. aureus isolates. Results Fifty-four cases of culture-confirmed post-partum S. aureus breast abscess were identified. Breastfeeding cessation (41%), milk fistula (11.1%) and hospital readmission (50%) occurred frequently among case patients. Breast abscess case patients had high rates of health services utilization compared to controls, including high rates of imaging and drainage procedures. The mean attributable cost of post-partum S. aureus breast abscess ranged from $2,340–$4,012, depending on the methods and data sources used. Mean attributable costs were not significantly higher among methicillin-resistant vs. –susceptible S. aureus cases. Conclusions Post-partum S. aureus breast abscess is associated with worse health and economic outcomes for women and their infants, including high rates of breastfeeding cessation. Future study is needed to determine the optimal treatment and prevention of these infections. PMID:24039877

Negotiating the "Middle" Ground: How English Learner (EL) Focused Teacher Leaders and Teachers Work towards EL Instructional Change in Mainstream Elementary School Classrooms

ERIC Educational Resources Information Center

Von Esch, Kerry Soo

2013-01-01

This dissertation investigates the relationship between district supported teacher leadership and improving the teaching and learning of English learner (EL) students, a rapidly growing, yet continually underserved population of students. Utilizing a comparative case study design, this dissertation focuses on the work of two district-supported…

School Leadership Practice and Preparation: Comparative Perspectives on Organizational Learning (OL), Instructional Leadership (IL) and Culturally Responsive Practices (CRP)

ERIC Educational Resources Information Center

Ylimaki, Rose; Jacobson, Stephen

2013-01-01

Purpose: The aim of this paper is to utilize successful leadership practices drawn from seven nations to improve leadership preparation. Design/methodology/approach: This study used a case study approach to gain a contextualized understanding of successful leadership across seven nations. Data sources primarily featured interviews with principals,…

Seven Principles of Instructional Content Design for a Remote Laboratory: A Case Study on ERRL

ERIC Educational Resources Information Center

Cagiltay, N. E.; Aydin, E.; Aydin, C. C.; Kara, A.; Alexandru, M.

2011-01-01

This paper discusses the results of a study of the requirements for developing a remote radio frequency (RF) laboratory for electrical engineering students. It investigates students' preferred usage of the technical content of a state-of-the-art RF laboratory. The results of this study are compared to previous findings, which dealt with other user…

"It's Sweeter Where the Bruise Is": Making Sense of the Experience of Family Homelessness in a Community-Campus Partnership

ERIC Educational Resources Information Center

Sandy, Marie

2014-01-01

Individual and family stories of homelessness that focus on the transition out of homelessness remain comparatively unexplored. Using hermeneutic inquiry and microstoria analysis to orient the inquiry and design the narrative, this case study involves the story of a woman overcoming homelessness with her family, and her participation in, and…

Deaf Readers and Phrasal Verbs: Instructional Efficacy of Chunking as a Visual Tool

ERIC Educational Resources Information Center

Atwell, William R.

2013-01-01

The purpose of this study was to examine the effectiveness of a visual strategy that of chunking or visually bracketing phrasal verbs in sentences in short stories. A descriptive case study design was used for this study to compare the two instructional strategies. In this study, stories were presented to 14 severely and profound deaf students…

Investigating Cognitive Processes within a Practical Art Context: A Phenomenological Case Study Focusing on Three Adolescents

ERIC Educational Resources Information Center

Hickman, Richard; Kiss, Lauren

2013-01-01

A phenomenological approach was employed in order to record and present the lived experiences of three students during a five-hour art-making activity. Theoretical definitions of cognitive processes pertinent to art and design were compared with the descriptions gathered from the students. The research was intended to portray as accurately as…

Effects of Video Modeling on the Instructional Efficiency of Simultaneous Prompting among Preschoolers with Autism Spectrum Disorder

ERIC Educational Resources Information Center

Genc-Tosun, Derya; Kurt, Onur

2017-01-01

The purpose of the present study was to compare the effectiveness and efficiency of simultaneous prompting with and without video modeling in teaching food preparation skills to four participants with autism spectrum disorder, whose ages ranged from 5 to 6 years old. An adapted alternating treatment single-case experimental design was used to…

Examining the Gender Identity of Language Teachers Using a Masculinity-Femininity Scale: A Case from Iran

ERIC Educational Resources Information Center

Pishghadam, Reza; Saboori, Fahime; Samavarchi, Laila; Hassanzadeh, Tahereh

2016-01-01

The present study pursued two goals: first, to construct and validate a masculinity/femininity scale (MFS); and second, to reveal and compare the dominant gender identity of English, Arabic, and Persian teachers. Regarding the first goal, a 30- item gender identity scale was designed and, using the data collected from 300 junior high school…

Using Screening Level Environmental Life Cycle Assessment to Aid Decision Making: A Case Study of a College Annual Report

ERIC Educational Resources Information Center

Ingwersen, Wesley W.; Curran, Mary Ann; Gonzalez, Michael A.; Hawkins, Troy R.

2012-01-01

Purpose: The purpose of this study is to compare the life cycle environmental impacts of the University of Cincinnati College of Engineering and Applied Sciences' current printed annual report to a version distributed via the internet. Design/methodology/approach: Life cycle environmental impacts of both versions of the report are modeled using…

Quality of Diagnosis and Treatment Plans after Using the "Diagnostic Guideline for Anxiety and Challenging Behaviours" in People with Intellectual Disabilities: A Comparative Multiple Case Study Design

ERIC Educational Resources Information Center

Pruijssers, Addy; van Meijel, Berno; Maaskant, Marian; Keeman, Noortje; van Achterberg, Theo

2016-01-01

Background: People with intellectual disabilities often have a multitude of concurrent problems due to the combination of cognitive impairments, psychiatric disorders (particularly anxiety) and related challenging behaviours. Diagnoses in people with intellectual disabilities are complicated. This study evaluates the quality of the diagnoses and…

Self-Administered Cued Naming Therapy: A Single-Participant Investigation of a Computer-Based Therapy Program Replicated in Four Cases

ERIC Educational Resources Information Center

Ramsberger, Gail; Marie, Basem

2007-01-01

Purpose: This study examined the benefits of a self-administered, clinician-guided, computer-based, cued naming therapy. Results of intense and nonintense treatment schedules were compared. Method: A single-participant design with multiple baselines across behaviors and varied treatment intensity for 2 trained lists was replicated over 4…

A Pilot Study of Cognitive-Behavioral Therapy of Insomnia in People with Mild Depression

ERIC Educational Resources Information Center

Taylor, Daniel J.; Lichstein, Kenneth L.; Weinstock, Jeremiah; Sanford, Stacy; Temple, Jeff R.

2007-01-01

In some cases, insomnia and depression may have a reciprocal relationship, in which each aggravates and maintains the other. To test the hypothesis that reduction of insomnia would result in reduction of depression in patients (N=10) with both disorders, a repeated-measures design was used comparing depression and insomnia levels before and after…

Evaluation of direct and indirect additive manufacture of maxillofacial prostheses.

PubMed

Eggbeer, Dominic; Bibb, Richard; Evans, Peter; Ji, Lu

2012-09-01

The efficacy of computer-aided technologies in the design and manufacture of maxillofacial prostheses has not been fully proven. This paper presents research into the evaluation of direct and indirect additive manufacture of a maxillofacial prosthesis against conventional laboratory-based techniques. An implant/magnet-retained nasal prosthesis case from a UK maxillofacial unit was selected as a case study. A benchmark prosthesis was fabricated using conventional laboratory-based techniques for comparison against additive manufactured prostheses. For the computer-aided workflow, photogrammetry, computer-aided design and additive manufacture (AM) methods were evaluated in direct prosthesis body fabrication and indirect production using an additively manufactured mould. Qualitative analysis of position, shape, colour and edge quality was undertaken. Mechanical testing to ISO standards was also used to compare the silicone rubber used in the conventional prosthesis with the AM material. Critical evaluation has shown that utilising a computer-aided work-flow can produce a prosthesis body that is comparable to that produced using existing best practice. Technical limitations currently prevent the direct fabrication method demonstrated in this paper from being clinically viable. This research helps prosthesis providers understand the application of a computer-aided approach and guides technology developers and researchers to address the limitations identified.

The accuracy of officially reported suicide statistics for purposes of epidemiological research.

PubMed Central

Sainsbury, P; Jenkins, J S

1982-01-01

Suicide is underreported for a number of reasons and the reliability of the official rates is subject to error from variation in defining and reporting cases--the kind of inaccuracies encountered when ascertaining cases in studies of mortality from any cause. Nevertheless, the evidence from studies designed to see whether these sources of error invalidate the differences reported between cultural and social groups indicate that they are randomised, at least to an extent that allows epidemiologists to compare rates between countries and districts within them, between demographic groups, and over time. PMID:7069354

Morbidity and Mortality Rounds in Liver Transplantation

PubMed Central

Kocabayoglu, Peri; Husen, Martin; Witzke, Oliver; Kribben, Andreas; Saner, Fuat H.; Canbay, Ali; Gerken, Guido; Paul, Andreas

2016-01-01

Background Morbidity and mortality conferences (MMCs) provide powerful opportunities for learning, reflection, and improvement. The current literature gives examples of how MMCs can be designed; however, no systematic review of cases and no original data related to liver transplantation are available. Liver transplantation requires a multidisciplinary approach to case identification, presentation, and analysis. Framework structures that guide case investigation are needed to successfully follow up on outcome measures and provide the basis for quality assessment and transparency in transplant programs. Methods All cases presented at our department's transplant-related MMCs in the years 2014 and 2015 were analyzed. Patient data were collected from our electronic database and meeting minutes. Cases were summarized according to type of transplantation. Liver-related transplant cases were analyzed for in-house deaths and time from death until presentation at an MMC. A literature review was performed, and our center's MMC design was compared with the literature available on conducting MMCs and improving patient safety and quality of care. Results Within 2 years, 15 MMCs were held at our department. 38 cases were discussed of which 25 were liver transplant-related. Most cases were in-house postoperative deaths, mainly due to sepsis or primary non-function. We provide a summary of recommendations for conducting MMCs based on conferences held in our department combined with the literature. Conclusion We present our experience with MMCs held over the past 24 months in consideration of guidelines on MMCs provided in the literature. As there is little conformity to known models for analyzing medical incidents, models for best practice in conduction MMCs are urgently needed. PMID:27722164

Introducing uncertainty analysis of nucleation and crystal growth models in Process Analytical Technology (PAT) system design of crystallization processes.

PubMed

Samad, Noor Asma Fazli Abdul; Sin, Gürkan; Gernaey, Krist V; Gani, Rafiqul

2013-11-01

This paper presents the application of uncertainty and sensitivity analysis as part of a systematic model-based process monitoring and control (PAT) system design framework for crystallization processes. For the uncertainty analysis, the Monte Carlo procedure is used to propagate input uncertainty, while for sensitivity analysis, global methods including the standardized regression coefficients (SRC) and Morris screening are used to identify the most significant parameters. The potassium dihydrogen phosphate (KDP) crystallization process is used as a case study, both in open-loop and closed-loop operation. In the uncertainty analysis, the impact on the predicted output of uncertain parameters related to the nucleation and the crystal growth model has been investigated for both a one- and two-dimensional crystal size distribution (CSD). The open-loop results show that the input uncertainties lead to significant uncertainties on the CSD, with appearance of a secondary peak due to secondary nucleation for both cases. The sensitivity analysis indicated that the most important parameters affecting the CSDs are nucleation order and growth order constants. In the proposed PAT system design (closed-loop), the target CSD variability was successfully reduced compared to the open-loop case, also when considering uncertainty in nucleation and crystal growth model parameters. The latter forms a strong indication of the robustness of the proposed PAT system design in achieving the target CSD and encourages its transfer to full-scale implementation. Copyright © 2013 Elsevier B.V. All rights reserved.

Importance of anthropogenic climate impact, sampling error and urban development in sewer system design.

PubMed

Egger, C; Maurer, M

2015-04-15

Urban drainage design relying on observed precipitation series neglects the uncertainties associated with current and indeed future climate variability. Urban drainage design is further affected by the large stochastic variability of precipitation extremes and sampling errors arising from the short observation periods of extreme precipitation. Stochastic downscaling addresses anthropogenic climate impact by allowing relevant precipitation characteristics to be derived from local observations and an ensemble of climate models. This multi-climate model approach seeks to reflect the uncertainties in the data due to structural errors of the climate models. An ensemble of outcomes from stochastic downscaling allows for addressing the sampling uncertainty. These uncertainties are clearly reflected in the precipitation-runoff predictions of three urban drainage systems. They were mostly due to the sampling uncertainty. The contribution of climate model uncertainty was found to be of minor importance. Under the applied greenhouse gas emission scenario (A1B) and within the period 2036-2065, the potential for urban flooding in our Swiss case study is slightly reduced on average compared to the reference period 1981-2010. Scenario planning was applied to consider urban development associated with future socio-economic factors affecting urban drainage. The impact of scenario uncertainty was to a large extent found to be case-specific, thus emphasizing the need for scenario planning in every individual case. The results represent a valuable basis for discussions of new drainage design standards aiming specifically to include considerations of uncertainty. Copyright © 2015 Elsevier Ltd. All rights reserved.

Understanding casing flow in Pelton turbines by numerical simulation

NASA Astrophysics Data System (ADS)

Rentschler, M.; Neuhauser, M.; Marongiu, J. C.; Parkinson, E.

2016-11-01

For rehabilitation projects of Pelton turbines, the flow in the casing may have an important influence on the overall performance of the machine. Water sheets returning on the jets or on the runner significantly reduce efficiency, and run-away speed depends on the flow in the casing. CFD simulations can provide a detailed insight into this type of flow, but these simulations are computationally intensive. As in general the volume of water in a Pelton turbine is small compared to the complete volume of the turbine housing, a single phase simulation greatly reduces the complexity of the simulation. In the present work a numerical tool based on the SPH-ALE meshless method is used to simulate the casing flow in a Pelton turbine. Using improved order schemes reduces the numerical viscosity. This is necessary to resolve the flow in the jet and on the casing wall, where the velocity differs by two orders of magnitude. The results are compared to flow visualizations and measurement in a hydraulic laboratory. Several rehabilitation projects proved the added value of understanding the flow in the Pelton casing. The flow simulation helps designing casing insert, not only to see their influence on the flow, but also to calculate the stress in the inserts. In some projects, the casing simulation leads to the understanding of unexpected behavior of the flow. One such example is presented where the backsplash of a deflector hit the runner, creating a reversed rotation of the runner.

Technology adoption and implementation in organisations: comparative case studies of 12 English NHS Trusts

PubMed Central

Ahmad, Raheelah; Holmes, Alison

2012-01-01

Objectives To understand organisational technology adoption (initiation, adoption decision, implementation) by looking at the different types of innovation knowledge used during this process. Design Qualitative, multisite, comparative case study design. Setting One primary care and 11 acute care organisations (trusts) across all health regions in England in the context of infection prevention and control. Participants and data analysis 121 semistructured individual and group interviews with 109 informants, involving clinical and non-clinical staff from all organisational levels and various professional groups. Documentary evidence and field notes were also used. 38 technology adoption processes were analysed using an integrated approach combining inductive and deductive reasoning. Main findings Those involved in the process variably accessed three types of innovation knowledge: ‘awareness’ (information that an innovation exists), ‘principles’ (information about an innovation's functioning principles) and ‘how-to’ (information required to use an innovation properly at individual and organisational levels). Centralised (national, government-led) and local sources were used to obtain this knowledge. Localised professional networks were preferred sources for all three types of knowledge. Professional backgrounds influenced an asymmetric attention to different types of innovation knowledge. When less attention was given to ‘how-to’ compared with ‘principles’ knowledge at the early stages of the process, this contributed to 12 cases of incomplete implementation or discontinuance after initial adoption. Conclusions Potential adopters and change agents often overlooked or undervalued ‘how-to’ knowledge. Balancing ‘principles’ and ‘how-to’ knowledge early in the innovation process enhanced successful technology adoption and implementation by considering efficacy as well as strategic, structural and cultural fit with the organisation's context. This learning is critical given the policy emphasis for health organisations to be innovation-ready. PMID:22492183

Sensitizing Carbon Nanotube Transistors for Single Molecule Sensor Applications

NASA Astrophysics Data System (ADS)

Collins, Philip G.; Akhterov, Maxim; Sims, Patrick C.; Fuller, Elliot J.; Gul, O. Tolga; Pan, Deng

2015-03-01

Recent work has demonstrated single-charge sensitivity in two types of carbon nanotube transistors. In one case, a two-level system near the nanotube or noncovalently attached to the nanotube perturbs the current electrostatically. In a second case, a sidewall defect or other covalent modification sensitizes one site along the conductor. Comparative research has helped reveal differences in the transduction mechanisms of the two cases and provides design rules for maximizing reliable signals for sensing applications. The covalent modifications are not mere perturbations and they are far more sensitive than noncovalent attachments, for example. However, the new degrees of freedom that accompany covalent disorder often have similar energy scales, leading to multiple independent fluctuations that degrade the overall signal-to-noise. Noncovalent sensitization generally produces a smaller signal amplitude in a background of other low-energy fluctuators, but a well-designed noncovalent linker can result in a highly predictable signal amplitudes. Furthermore, noncovalent fabrication methods are scalable, so that wafer-scale arrays of molecular sensors are most likely to follow this path. This work was supported by NSF (ECCS-1231910).

True double bifurcation lesions: new application of the self-expandable Axxess stent and review of literature with dedicated bifurcation devices.

PubMed

Borgia, Francesco; Niglio, Tullio; De Luca, Nicola; Di Serafino, Luigi; Esposito, Giovanni; Trimarco, Bruno; Cirillo, Plinio

2018-04-21

Complex coronary artery bifurcation lesions occurred in hard clinical scenarios, such as acute coronary syndromes, may represent a challenge for interventional cardiologists, with not-defined general consensus on treatment. Even if provisional stenting is the most common option used to restore rapidly the coronary branches flow, improvements in industrial technologies and design of new dedicated bifurcation devices might open new modalities of treatment in these complex cases. The Axxess stent (Biosensors Europe SA, Morges, Switzerland) is a self-expanding biolimus-eluting conical V-shape stent, specifically designed to treat "easily" coronary artery bifurcation lesions, with reported favorable long-term clinical results in stable patients compared to a provisional technique. We report for the first time the feasibility to use this device in a case of "true double coronary bifurcation lesion" occurred in the context of acute coronary syndrome. Moreover, we reviewed studies with bifurcation dedicated devices and available cases of "true double bifurcation lesions", underlying advantages/disadvantages of using one device over the others during acute coronary syndrome. Copyright © 2018 Elsevier Inc. All rights reserved.

An approximate theoretical method for modeling the static thrust performance of non-axisymmetric two-dimensional convergent-divergent nozzles. M.S. Thesis - George Washington Univ.

NASA Technical Reports Server (NTRS)

Hunter, Craig A.

1995-01-01

An analytical/numerical method has been developed to predict the static thrust performance of non-axisymmetric, two-dimensional convergent-divergent exhaust nozzles. Thermodynamic nozzle performance effects due to over- and underexpansion are modeled using one-dimensional compressible flow theory. Boundary layer development and skin friction losses are calculated using an approximate integral momentum method based on the classic karman-Polhausen solution. Angularity effects are included with these two models in a computational Nozzle Performance Analysis Code, NPAC. In four different case studies, results from NPAC are compared to experimental data obtained from subscale nozzle testing to demonstrate the capabilities and limitations of the NPAC method. In several cases, the NPAC prediction matched experimental gross thrust efficiency data to within 0.1 percent at a design NPR, and to within 0.5 percent at off-design conditions.

Development of a high-specific-speed centrifugal compressor

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

Rodgers, C.

1997-07-01

This paper describes the development of a subscale single-stage centrifugal compressor with a dimensionless specific speed (Ns) of 1.8, originally designed for full-size application as a high volume flow, low pressure ratio, gas booster compressor. The specific stage is noteworthy in that it provides a benchmark representing the performance potential of very high-specific-speed compressors, of which limited information is found in the open literature. Stage and component test performance characteristics are presented together with traverse results at the impeller exit. Traverse test results were compared with recent CFD computational predictions for an exploratory analytical calibration of a very high-specific-speed impellermore » geometry. The tested subscale (0.583) compressor essentially satisfied design performance expectations with an overall stage efficiency of 74% including, excessive exit casing losses. It was estimated that stage efficiency could be increased to 81% with exit casing losses halved.« less

Therapeutic Horseback Riding Outcomes of Parent-Identified Goals for Children with Autism Spectrum Disorder: An ABA′ Multiple Case Design Examining Dosing and Generalization to the Home and Community

PubMed Central

Baird, Joanne M.; Kim, Young Joo; Rajora, Kuwar B.; D’Silva, Delma; Podolinsky, Lin; Mazefsky, Carla; Minshew, Nancy

2014-01-01

We examined whether different doses of therapeutic riding influenced parent-nominated target behaviors of children with autism spectrum disorder (ASD) (a) during the session (b) at home, and (c) in the community. We used a single subject multiple Baseline, multiple case design, with dosing of 1, 3, and 5 times/week. Three boys with ASD, 6–8 years of age participated, and counts of target behaviors were collected in each setting and phase of the study. Compared to Baseline, 70 % of the target behaviors were better during Intervention and improvement was retained in 63 % of the behaviors during Withdrawal. Increased doses of therapeutic riding were significant for magnitude of change, and the effect of the therapeutic riding sessions generalized to home and community. PMID:24091469

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.

Large-eddy simulation of turbulent flow with a surface-mounted two-dimensional obstacle

NASA Technical Reports Server (NTRS)

Yang, Kyung-Soo; Ferziger, Joel H.

1993-01-01

In this paper, we perform a large eddy simulation (LES) of turbulent flow in a channel containing a two-dimensional obstacle on one wall using a dynamic subgrid-scale model (DSGSM) at Re = 3210, based on bulk velocity above the obstacle and obstacle height; the wall layers are fully resolved. The low Re enables us to perform a DNS (Case 1) against which to validate the LES results. The LES with the DSGSM is designated Case 2. In addition, an LES with the conventional fixed model constant (Case 3) is conducted to allow identification of improvements due to the DSGSM. We also include LES at Re = 82,000 (Case 4) using conventional Smagorinsky subgrid-scale model and a wall-layer model. The results will be compared with the experiment of Dimaczek et al.

How well do the DSM-5 alcohol use disorder designations map to the ICD-10 disorders?

PubMed

Hoffmann, Norman G; Kopak, Albert M

2015-04-01

The Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5), and the International Statistical Classification of Diseases and Related Health Problems, 10th edition (ICD-10), both establish diagnostic criteria for alcohol use disorders. The dimensional severity perspective provided by the DSM-5 may overlap in important ways but also may diverge from the categorical harmful use versus dependence designations presented by the ICD-10. It is especially important to consider the convergence of these 2 diagnostic approaches as the DSM is widely used by clinicians, but the U.S. Centers for Medicare and Medicaid Services has recently required that providers bill for services using the ICD-10 designations. Data from 6,871 male and 801 female admissions to a state prison system were used to compare the DSM-5 severity index for alcohol use disorder to the ICD-10 clinical and research formulations for harmful use and dependence. The DSM-5 and the ICD-10 were highly convergent for the most severe alcohol use disorders and also for those who did not receive a diagnosis. Most DSM-5 moderate alcohol use disorder cases were classified as dependence cases under both the clinical and research ICD criteria. In contrast, there was much more variation in the DSM mild cases. These were divided into categories of harmful use or misuse, depending on whether the clinical or research ICD criteria were applied. Results were similar among male and female inmates. The DSM-5 and ICD-10 exhibit a high level of agreement for cases that would not receive a diagnosis as well as the most severe cases. However, there are important distinctions to be made between the 2 approaches for mild and moderate DSM disorders in addition to harmful use/misuse cases in the ICD. The cases influenced by these discrepancies are most likely to be affected by recently implemented service provider billing practices. Copyright © 2015 by the Research Society on Alcoholism.

Predicted energy densitites for nickel-hydrogen and silver-hydrogen cells embodying metallic hydrides for hydrogen storage

NASA Technical Reports Server (NTRS)

Easter, R. W.

1974-01-01

Simplified design concepts were used to estimate gravimetric and volumetric energy densities for metal hydrogen battery cells for assessing the characteristics of cells containing metal hydrides as compared to gaseous storage cells, and for comparing nickel cathode and silver cathode systems. The silver cathode was found to yield superior energy densities in all cases considered. The inclusion of hydride forming materials yields cells with very high volumetric energy densities that also retain gravimetric energy densities nearly as high as those of gaseous storage cells.

Electromechanical converters for electric vehicles

NASA Astrophysics Data System (ADS)

Ambros, T.; Burduniuc, M.; Deaconu, S. I.; Rujanschi, N.

2018-01-01

The paper presents the analysis of various constructive schemes of synchronous electromechanical converters with permanent magnets fixed on the rotor and asynchronous with the short-circuit rotor. Various electrical stator winding schemes have also been compared, demonstrating the efficiency of copper utilization in toroidal windings. The electromagnetic calculus of the axial machine has particularities compared to the cylindrical machine, in the paper is presented the method of correlating the geometry of the cylindrical and axial machines. In this case the method and recommendations used in the design of such machines may be used.

Response of lead-acid batteries to chopper-controlled discharge: Preliminary results

NASA Technical Reports Server (NTRS)

Cataldo, R. L.

1978-01-01

The preliminary results of simulated electric vehicle, chopper, speed controller discharge of a battery show energy output losses up to 25 percent compared to constant current discharges at the same average discharge current of 100 amperes. These energy losses are manifested as temperature rises during discharge, amounting to a two-fold increase for a 400-ampere pulse compared to the constant current case. Because of the potentially large energy inefficiency, the results suggest that electric vehicle battery/speed controller interaction must be carefully considered in vehicle design.

Response of lead-acid batteries to chopper-controlled discharge

NASA Technical Reports Server (NTRS)

Cataldo, R. L.

1978-01-01

The preliminary results of simulated electric vehicle, chopper, speed controller discharge of a battery show energy output losses at up to 25 percent compared to constant current discharges at the same average discharge current of 100 A. These energy losses are manifested as temperature rises during discharge, amounting to a two-fold increase for a 400-A pulse compared to the constant current case. Because of the potentially large energy inefficiency, the results suggest that electric vehicle battery/speed controller interaction must be carefully considered in vehicle design.

Evaluation of caregiver-friendly workplace policy (CFWPs) interventions on the health of full-time caregiver employees (CEs): implementation and cost-benefit analysis.

PubMed

Williams, Allison M; Tompa, Emile; Lero, Donna S; Fast, Janet; Yazdani, Amin; Zeytinoglu, Isik U

2017-09-20

Current Canadian evidence illustrating the health benefits and cost-effectiveness of caregiver-friendly workplace policies is needed if Canadian employers are to adopt and integrate caregiver-friendly workplace policies into their employment practices. The goal of this three-year, three study research project is to provide such evidence for the auto manufacturing and educational services sectors. The research questions being addressed are: What are the impacts for employers (economic) and workers (health) of caregiver-friendly workplace policy intervention(s) for full-time caregiver-employees? What are the impacts for employers, workers and society of the caregiver-friendly workplace policy intervention(s) in each participating workplace? What contextual factors impact the successful implementation of caregiver-friendly workplace policy intervention(s)? Using a pre-post-test comparative case study design, Study A will determine the effectiveness of newly implemented caregiver-friendly workplace policy intervention(s) across two workplaces to determine impacts on caregiver-employee health. A quasi-experimental pre-post design will allow the caregiver-friendly workplace policy intervention(s) to be tested with respect to potential impacts on health, and specifically on caregiver employee mental, psychosocial, and physical health. Framed within a comparative case study design, Study B will utilize cost-benefit and cost-effectiveness analysis approaches to evaluate the economic impacts of the caregiver-friendly workplace policy intervention(s) for each of the two participating workplaces. Framed within a comparative case study design, Study C will undertake an implementation analysis of the caregiver-friendly workplace policy intervention(s) in each participating workplace in order to determine: the degree of support for the intervention(s) (reflected in the workplace culture); how sex and gender are implicated; co-workers' responses to the chosen intervention(s), and; other nuances at play. It is hypothesized that the benefits of the caregiver-friendly workplace policy intervention(s) will include improvements in caregiver-employees' mental, psychosocial and physical health, as well as evidence of cost-benefit and cost-effectiveness for the employer. The expected project results will provide the research evidence for extensive knowledge translation work, to be carried out in collaboration with our knowledge transition partners, to the employer/human resources and occupational health/safety target populations. ISRCTN16187974 Registered August 25, 2016.

Comparing problem-based learning and lecture as methods to teach whole-systems design to engineering students

NASA Astrophysics Data System (ADS)

Dukes, Michael Dickey

The objective of this research is to compare problem-based learning and lecture as methods to teach whole-systems design to engineering students. A case study, Appendix A, exemplifying successful whole-systems design was developed and written by the author in partnership with the Rocky Mountain Institute. Concepts to be tested were then determined, and a questionnaire was developed to test students' preconceptions. A control group of students was taught using traditional lecture methods, and a sample group of students was taught using problem-based learning methods. After several weeks, the students were given the same questionnaire as prior to the instruction, and the data was analyzed to determine if the teaching methods were effective in correcting misconceptions. A statistically significant change in the students' preconceptions was observed in both groups on the topic of cost related to the design process. There was no statistically significant change in the students' preconceptions concerning the design process, technical ability within five years, and the possibility of drastic efficiency gains with current technologies. However, the results were inconclusive in determining that problem-based learning is more effective than lecture as a method for teaching the concept of whole-systems design, or vice versa.

Simulations as a tool for higher mass resolution spectrometer: Lessons from existing observations

NASA Astrophysics Data System (ADS)

Nicolaou, Georgios; Yamauchi, Masatoshi; Nilsson, Hans; Wieser, Martin; Fedorov, Andrei

2017-04-01

Scientific requirements of each mission are crucial for the instrument's design. Ion tracing simulations of instruments can be helpful to characterize their performance, identify their limitations and improving the design for future missions. However, simulations provide the best performance in ideal case, and the actual response is determined by many other factors. Therefore, simulations should be compared with observations when possible. Characterizing the actual response of a running instrument gives valuable lessons for the future design of test instruments with the same detection principle before spending resources to build and calibrate them. In this study we use an ion tracing simulation of the Ion Composition Analyser (ICA) on board ROSETTA, in order to characterize its response and to compare it with the observations. It turned out that, due to the complicated unexpected response of the running instrument, the heavy cometary ions and molecules are sometimes difficult to be resolved. However, preliminary simulation of a slightly modified design predicts much higher mass resolution. Even after considering the complicated unexpected response, we safely expect that the modified design can resolve most abundant heavy atomic ions (e.g., O^+) and molecular ions (e.g., N_2+ and O_2^+). We show the simulation results for both designs and ICA data.

A spiral, bi-planar gradient coil design for open magnetic resonance imaging.

PubMed

Zhang, Peng; Shi, Yikai; Wang, Wendong; Wang, Yaohui

2018-01-01

To design planar gradient coil for MRI applications without discretization of continuous current density and loop-loop connection errors. In the new design method, the coil current is represented using a spiral curve function described by just a few control parameters. Using a proper parametric equation set, an ensemble of spiral contours is reshaped to satisfy the coil design requirements, such as gradient linearity, inductance and shielding. In the given case study, by using the spiral coil design, the magnetic field errors in the imaging area were reduced from 5.19% (non-spiral design) to 4.47% (spiral design) for the transverse gradient coils, and for the longitudinal gradient coil design, the magnetic field errors were reduced to 5.02% (spiral design). The numerical evaluation shows that when compared with conventional wire loop, the inductance and resistance of spiral coil was reduced by 11.55% and 8.12% for x gradient coil, respectively. A novel spiral gradient coil design for biplanar MRI systems, the new design offers better magnetic field gradients, smooth contours than the conventional connected counterpart, which improves manufacturability.

Intensive case management for high-risk patients with first-episode psychosis: service model and outcomes.

PubMed

Brewer, Warrick J; Lambert, Timothy J; Witt, Katrina; Dileo, John; Duff, Cameron; Crlenjak, Carol; McGorry, Patrick D; Murphy, Brendan P

2015-01-01

The first episode of psychosis is a crucial period when early intervention can alter the trajectory of the young person's ongoing mental health and general functioning. After an investigation into completed suicides in the Early Psychosis Prevention and Intervention Centre (EPPIC) programme, the intensive case management subprogramme was developed in 2003 to provide assertive outreach to young people having a first episode of psychosis who are at high risk owing to risk to self or others, disengagement, or suboptimal recovery. We report intensive case management model development, characterise the target cohort, and report on outcomes compared with EPPIC treatment as usual. Inclusion criteria, staff support, referral pathways, clinical review processes, models of engagement and care, and risk management protocols are described. We compared 120 consecutive referrals with 50 EPPIC treatment as usual patients (age 15-24 years) in a naturalistic stratified quasi-experimental real-world design. Key performance indicators of service use plus engagement and suicide attempts were compared between EPPIC treatment as usual and intensive case management, and psychosocial and clinical measures were compared between intensive case management referral and discharge. Referrals were predominately unemployed males with low levels of functioning and educational attainment. They were characterised by a family history of mental illness, migration and early separation, with substantial trauma, history of violence, and forensic attention. Intensive case management improved psychopathology and psychosocial outcomes in high-risk patients and reduced risk ratings, admissions, bed days, and crisis contacts. Characterisation of intensive case management patients validated the clinical research focus and identified a first episode of psychosis high-risk subgroup. In a real-world study, implementation of an intensive case management stream within a well-established first episode of psychosis service showed significant improvement in key service outcomes. Further analysis is needed to determine cost savings and effects on psychosocial outcomes. Targeting intensive case management services to high-risk patients with unmet needs should reduce the distress associated with pathways to care for patients, their families, and the community. National Health & Medical Research Council and the Colonial Foundation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Design, Optimization and Evaluation of Integrally Stiffened Al 7050 Panel with Curved Stiffeners

NASA Technical Reports Server (NTRS)

Slemp, Wesley C. H.; Bird, R. Keith; Kapania, Rakesh K.; Havens, David; Norris, Ashley; Olliffe, Robert

2011-01-01

A curvilinear stiffened panel was designed, manufactured, and tested in the Combined Load Test Fixture at NASA Langley Research Center. The panel was optimized for minimum mass subjected to constraints on buckling load, yielding, and crippling or local stiffener failure using a new analysis tool named EBF3PanelOpt. The panel was designed for a combined compression-shear loading configuration that is a realistic load case for a typical aircraft wing panel. The panel was loaded beyond buckling and strains and out-of-plane displacements were measured. The experimental data were compared with the strains and out-of-plane deflections from a high fidelity nonlinear finite element analysis and linear elastic finite element analysis of the panel/test-fixture assembly. The numerical results indicated that the panel buckled at the linearly elastic buckling eigenvalue predicted for the panel/test-fixture assembly. The experimental strains prior to buckling compared well with both the linear and nonlinear finite element model.

Diffraction-limited lucky imaging with a 12" commercial telescope

NASA Astrophysics Data System (ADS)

Baptista, Brian J.

2014-08-01

Here we demonstrate a novel lucky imaging camera which is designed to produce diffraction-limited imaging using small telescopes similar to ones used by many academic institutions for outreach and/or student training. We present a design that uses a Meade 12" SCT paired with an Andor iXon fast readout EMCCD. The PSF of the telescope is matched to the pixel size of the EMCCD by adding a simple, custom-fabricated, intervening optical system. We demonstrate performance of the system by observing both astronomical and terrestrial targets. The astronomical application requires simpler data reconstruction techniques as compared to the terrestrial case. We compare different lucky imaging registration and reconstruction algorithms for use with this imager for both astronomical and terrestrial targets. We also demonstrate how this type of instrument would be useful for both undergraduate and graduate student training. As an instructional aide, the instrument can provide a hands-on approach for teaching instrument design, standard data reduction techniques, lucky imaging data processing, and high resolution imaging concepts.

An automated high throughput tribometer for adhesion, wear, and friction measurements

NASA Astrophysics Data System (ADS)

Kalihari, Vivek; Timpe, Shannon J.; McCarty, Lyle; Ninke, Matthew; Whitehead, Jim

2013-03-01

Understanding the origin and correlation of different surface properties under a multitude of operating conditions is critical in tribology. Diverse tribological properties and a lack of a single instrument to measure all make it difficult to compare and correlate properties, particularly in light of the wide range of interfaces commonly investigated. In the current work, a novel automated tribometer has been designed and validated, providing a unique experimental platform capable of high throughput adhesion, wear, kinetic friction, and static friction measurements. The innovative design aspects are discussed that allow for a variety of probes, sample surfaces, and testing conditions. Critical components of the instrument and their design criteria are described along with examples of data collection schemes. A case study is presented with multiple surface measurements performed on a set of characteristic substrates. Adhesion, wear, kinetic friction, and static friction are analyzed and compared across surfaces, highlighting the comprehensive nature of the surface data that can be generated using the automated high throughput tribometer.

Theoretical Basis of the Test-Negative Study Design for Assessment of Influenza Vaccine Effectiveness.

PubMed

Sullivan, Sheena G; Tchetgen Tchetgen, Eric J; Cowling, Benjamin J

2016-09-01

Influenza viruses undergo frequent antigenic changes. As a result, the viruses circulating change within and between seasons, and the composition of the influenza vaccine is updated annually. Thus, estimation of the vaccine's effectiveness is not constant across seasons. In order to provide annual estimates of the influenza vaccine's effectiveness, health departments have increasingly adopted the "test-negative design," using enhanced data from routine surveillance systems. In this design, patients presenting to participating general practitioners with influenza-like illness are swabbed for laboratory testing; those testing positive for influenza virus are defined as cases, and those testing negative form the comparison group. Data on patients' vaccination histories and confounder profiles are also collected. Vaccine effectiveness is estimated from the odds ratio comparing the odds of testing positive for influenza among vaccinated patients and unvaccinated patients, adjusting for confounders. The test-negative design is purported to reduce bias associated with confounding by health-care-seeking behavior and misclassification of cases. In this paper, we use directed acyclic graphs to characterize potential biases in studies of influenza vaccine effectiveness using the test-negative design. We show how studies using this design can avoid or minimize bias and where bias may be introduced with particular study design variations. © The Author 2016. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Unintentional Epinephrine Auto-injector Injuries: A National Poison Center Observational Study.

PubMed

Anshien, Marco; Rose, S Rutherfoord; Wills, Brandon K

2016-11-24

Epinephrine is the only first-line therapeutic agent used to treat life-threatening anaphylaxis. Epinephrine auto-injectors are commonly carried by patients at risk for anaphylaxis, and reported cases of unintentional auto-injector injury have increased over the last decade. Modifications of existing designs and release of a new style of auto-injector are intended to reduce epinephrine auto-injector misuse. The aim of the study was to characterize reported cases of unintentional epinephrine auto-injector exposures from 2013 to 2014 and compare demographics, auto-injector model, and anatomical site of such exposures. The American Association of Poison Control Center's National Poison Data System was searched from January 1, 2013, to December 31, 2014, for cases of unintentional epinephrine auto-injector exposures. Anatomical site data were obtained from all cases reported to the Virginia Poison Center and participating regional poison center for Auvi-Q cases. A total of 6806 cases of unintentional epinephrine auto-injector exposures were reported to US Poison Centers in 2013 and 2014. Of these cases, 3933 occurred with EpiPen, 2829 with EpiPen Jr, 44 with Auvi-Q, and no case reported of Adrenaclick. The most common site of unintentional injection for traditional epinephrine auto-injectors was the digit or thumb, with 58% of cases for EpiPen and 39% of cases with EpiPen Jr. With Auvi-Q, the most common site was the leg (78% of cases). The number of unintentional epinephrine auto-injector cases reported to American Poison Centers in 2013-2014 has increased compared with previous data. Most EpiPen exposures were in the digits, whereas Auvi-Q was most frequently in the leg. Because of the limitations of Poison Center data, more research is needed to identify incidence of unintentional exposures and the effectiveness of epinephrine auto-injector redesign.

Implementation of improved underbalanced drilling in AbuDhabi onshore field

NASA Astrophysics Data System (ADS)

Alhammadi, Adel Mohammed

Abu Dhabi Company for Onshore Oil Operations (ADCO) is considering Underbalanced Drilling (UBD) as a means to develop lower permeability units in its fields. In addition to productivity and recovery gains, ADCO also expects reservoir characterization benefits from UBD. Reservoir screening studies were carried out on all of ADCO's reservoirs to determine their applicability for UBD. The primary business benefits of UBD were determined to be reservoir characterization, damage Mitigation, and rate of Penetration "ROP" Improvement. Apart from the primary benefits, some of the secondary benefits of UBD that were identified beforehand included rig performance. Since it's a trial wells, the challenge was to drill these wells safely, efficiently and of course meeting well objectives. Many operators worldwide drill these well in underbalanced mode but complete it overbalanced. In our case the plan was to drill and complete these wells in underbalanced condition. But we had to challenge most operators and come up with special and unique casing hanger design to ensure well control barriers exists while fishing the control line of the Downhole Deployment Valve "DDV". After intensive studies and planning, the hanger was designed as per our recommendations and found to be effective equipment that optimized the operational time and the cost as well. This report will provide better understanding of UBD technique in general and shade on the special designed casing hanger compared to conventional or what's most used worldwide. Even thought there were some issues while running the casing hanger prior drilling but managed to capture the learning's from each well and re-modified the hanger and come up with better deign for the future wells. Finally, the new design perform a good performance of saving the operation time and assisting the project to be done in a safe and an easy way without a major impact on the well cost. This design helped to drill and complete these wells safely with requirement to kill the wells and this ensured least reservoir damage.

Life cycle assessment based environmental impact estimation model for pre-stressed concrete beam bridge in the early design phase

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

Kim, Kyong Ju, E-mail: kjkim@cau.ac.kr; Yun, Won Gun, E-mail: ogun78@naver.com; Cho, Namho, E-mail: nhc51@cau.ac.kr

The late rise in global concern for environmental issues such as global warming and air pollution is accentuating the need for environmental assessments in the construction industry. Promptly evaluating the environmental loads of the various design alternatives during the early stages of a construction project and adopting the most environmentally sustainable candidate is therefore of large importance. Yet, research on the early evaluation of a construction project's environmental load in order to aid the decision making process is hitherto lacking. In light of this dilemma, this study proposes a model for estimating the environmental load by employing only the mostmore » basic information accessible during the early design phases of a project for the pre-stressed concrete (PSC) beam bridge, the most common bridge structure. Firstly, a life cycle assessment (LCA) was conducted on the data from 99 bridges by integrating the bills of quantities (BOQ) with a life cycle inventory (LCI) database. The processed data was then utilized to construct a case based reasoning (CBR) model for estimating the environmental load. The accuracy of the estimation model was then validated using five test cases; the model's mean absolute error rates (MAER) for the total environmental load was calculated as 7.09%. Such test results were shown to be superior compared to those obtained from a multiple-regression based model and a slab area base-unit analysis model. Henceforth application of this model during the early stages of a project is expected to highly complement environmentally friendly designs and construction by facilitating the swift evaluation of the environmental load from multiple standpoints. - Highlights: • This study is to develop the model of assessing the environmental impacts on LCA. • Bills of quantity from completed designs of PSC Beam were linked with the LCI DB. • Previous cases were used to estimate the environmental load of new case by CBR model. • CBR model produces more accurate estimations (7.09%) than other conventional models. • This study supports decision making process in the early stage of a new construction case.« less

Do the design concepts used for the space flight hardware directly affect cell structure and/or cell function ground based simulations

NASA Technical Reports Server (NTRS)

Chapman, David K.

1989-01-01

The use of clinostats and centrifuges to explore the hypogravity range between zero and 1 g is described. Different types of clinostat configurations and clinostat-centrifuge combinations are compared. Some examples selected from the literature and current research in gravitational physiology are presented to show plant responses in the simulated hypogravity region of the g-parameter (0 is greater than g is greater than 1). The validation of clinostat simulation is discussed. Examples in which flight data can be compared to clinostat data are presented. The data from 3 different laboratories using 3 different plant species indicate that clinostat simulation in some cases were qualitatively similar to flight data, but that in all cases were quantitatively different. The need to conduct additional tests in weightlessness is emphasized.

Improved Shaping Approach to the Preliminary Design of Low-Thrust Trajectories

NASA Astrophysics Data System (ADS)

Novak, D. M.; Vasile, M.

2011-01-01

This paper presents a general framework for the development of shape-based approaches to low-thrust trajectory design. A novel shaping method, based on a three-dimensional description of the trajectory in spherical coordinates, is developed within this general framework. Both the exponential sinusoid and the inverse polynomial shaping are demonstrated to be particular two-dimensional cases of the spherical one. The pseudoequinoctial shaping is revisited within the new framework, and the nonosculating nature of the pseudoequinoctial elements is analyzed. A two-step approach is introduced to solve the time of flight constraint, related to the design of low-thrust arcs with boundary constraints for both spherical and pseudoequinoctial shaping. The solution derived from the shaping approach is improved with a feedback linear-quadratic controller and compared against a direct collocation method based on finite elements in time. The new shaping approach and the combination of shaping and linear-quadratic controller are tested on three case studies: a mission to Mars, a mission to asteroid 1989ML, a mission to comet Tempel-1, and a mission to Neptune.

Experimental comparison of conventional and nonlinear model-based control of a mixing tank

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

Haeggblom, K.E.

1993-11-01

In this case study concerning control of a laboratory-scale mixing tank, conventional multiloop single-input single-output (SISO) control is compared with model-based'' control where the nonlinearity and multivariable characteristics of the process are explicitly taken into account. It is shown, especially if the operating range of the process is large, that the two outputs (level and temperature) cannot be adequately controlled by multiloop SISO control even if gain scheduling is used. By nonlinear multiple-input multiple-output (MIMO) control, on the other hand, very good control performance is obtained. The basic approach to nonlinear control used in this study is first to transformmore » the process into a globally linear and decoupled system, and then to design controllers for this system. Because of the properties of the resulting MIMO system, the controller design is very easy. Two nonlinear control system designs based on a steady-state and a dynamic model, respectively, are considered. In the dynamic case, both setpoint tracking and disturbance rejection can be addressed separately.« less

An Experimental Design of Bypass Magneto-Rheological (MR) damper

NASA Astrophysics Data System (ADS)

Rashid, MM; Aziz, Mohammad Abdul; Raisuddin Khan, Md.

2017-11-01

The magnetorheological (MR) fluid bypass damper fluid flow through a bypass by utilizing an external channel which allows the controllability of MR fluid in the channel. The Bypass MR damper (BMRD) contains a rectangular bypass flow channel, current controlled movable piston shaft arrangement and MR fluid. The static piston coil case is winding by a coil which is used inside the piston head arrangement. The current controlled coil case provides a magnetic flux through the BMRD cylinder for controllability. The high strength of alloy steel materials are used for making piston shaft which allows magnetic flux propagation throughout the BMRD cylinder. Using the above design materials, a Bypass MR damper is designed and tested. An excitation of current is applied during the experiment which characterizes the BMRD controllability. It is shown that the BMRD with external flow channel allows a high controllable damping force using an excitation current. The experimental result of damping force-displacement characteristics with current excitation and without current excitation are compared in this research. The BMRD model is validated by the experimental result at various frequencies and applied excitation current.

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

Mankamo, T.; Kim, I.S.; Yang, Ji Wu

Failures in the auxiliary feedwater (AFW) system of pressurized water reactors (PWRs) are considered to involve substantial risk whether a decision is made to either continue power operation while repair is being done, or to shut down the plant to undertake repairs. Technical specification action requirements usually require immediate plant shutdown in the case of multiple failures in the system (in some cases, immediate repair of one train is required when all AFW trains fail). This paper presents a probabilistic risk assessment-based method to quantitatively evaluate and compare both the risks of continued power operation and of shutting the plantmore » down, given known failures in the system. The method is applied to the AFW system for four different PWRs. Results show that the risk of continued power operation and plant shutdown both are substantial, but the latter is larger than the former over the usual repair time. This was proven for four plants with different designs: two operating Westinghouse plants, one operating Asea-Brown Boveri Combustion Engineering Plant, and one of evolutionary design. The method can be used to analyze individual plant design and to improve AFW action requirements using risk-informed evaluations.« less

Cytokine response signatures in disease progression and development of severe clinical outcomes for leptospirosis.

PubMed

Reis, Eliana A G; Hagan, José E; Ribeiro, Guilherme S; Teixeira-Carvalho, Andrea; Martins-Filho, Olindo A; Montgomery, Ruth R; Shaw, Albert C; Ko, Albert I; Reis, Mitermayer G

2013-01-01

The role of the immune response in influencing leptospirosis clinical outcomes is not yet well understood. We hypothesized that acute-phase serum cytokine responses may play a role in disease progression, risk for death, and severe pulmonary hemorrhage syndrome (SPHS). We performed a case-control study design to compare cytokine profiles in patients with mild and severe forms of leptospirosis. Among patients hospitalized with severe disease, we compared those with fatal and nonfatal outcomes. During active outpatient and hospital-based surveillance we prospectively enrolled 172 patients, 23 with mild disease (outpatient) and 149 with severe leptospirosis (hospitalized). Circulating concentrations of pro- and anti-inflammatory cytokines at the time of patient presentation were measured using a multiplex bead array assay. Concentrations of IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-17A, and TNF-α were significantly higher (P<0.05) in severe disease compared to mild disease. Among severe patients, levels of IL-6 (P<0.001), IL-8 (P = 0.0049) and IL-10 (P<0.001), were higher in fatal compared to non-fatal cases. High levels of IL-6 and IL-10 were independently associated (P<0.05) with case fatality after adjustment for age and days of symptoms. IL-6 levels were higher (P = 0.0519) among fatal cases who developed SPHS than among who did not. This study shows that severe cases of leptospirosis are differentiated from mild disease by a "cytokine storm" process, and that IL-6 and IL-10 may play an immunopathogenic role in the development of life-threatening outcomes in human leptospirosis.

Application of Optimization Techniques to Spectrally Modulated, Spectrally Encoded Waveform Design

DTIC Science & Technology

2008-09-01

means y1 and y2 do indeed differ [22]. 43 To compare means for more than two populations, the Least Significant Difference ( LSD ) test may be used...case, the LSD test for a full-factorial design is given by LSD = tα 2 ,Ne−a √ 2 eTe n(Ne − a) , (2.41) where α is the significance level and ν = Ne − a...rejected if the means differ by more than the LSD [22]. 44 III. Methodology In many respects, the goal of this dissertation is to develop and

Optimization of composite box-beam structures including effects of subcomponent interactions

NASA Technical Reports Server (NTRS)

Ragon, Scott A.; Guerdal, Zafer; Starnes, James H., Jr.

1995-01-01

Minimum mass designs are obtained for a simple box beam structure subject to bending, torque and combined bending/torque load cases. These designs are obtained subject to point strain and linear buckling constraints. The present work differs from previous efforts in that special attention is payed to including the effects of subcomponent panel interaction in the optimal design process. Two different approaches are used to impose the buckling constraints. When the global approach is used, buckling constraints are imposed on the global structure via a linear eigenvalue analysis. This approach allows the subcomponent panels to interact in a realistic manner. The results obtained using this approach are compared to results obtained using a traditional, less expensive approach, called the local approach. When the local approach is used, in-plane loads are extracted from the global model and used to impose buckling constraints on each subcomponent panel individually. In the global cases, it is found that there can be significant interaction between skin, spar, and rib design variables. This coupling is weak or nonexistent in the local designs. It is determined that weight savings of up to 7% may be obtained by using the global approach instead of the local approach to design these structures. Several of the designs obtained using the linear buckling analysis are subjected to a geometrically nonlinear analysis. For the designs which were subjected to bending loads, the innermost rib panel begins to collapse at less than half the intended design load and in a mode different from that predicted by linear analysis. The discrepancy between the predicted linear and nonlinear responses is attributed to the effects of the nonlinear rib crushing load, and the parameter which controls this rib collapse failure mode is shown to be the rib thickness. The rib collapse failure mode may be avoided by increasing the rib thickness above the value obtained from the (linear analysis based) optimizer. It is concluded that it would be necessary to include geometric nonlinearities in the design optimization process if the true optimum in this case were to be found.

Design, Development and Analysis of Centrifugal Blower

NASA Astrophysics Data System (ADS)

Baloni, Beena Devendra; Channiwala, Salim Abbasbhai; Harsha, Sugnanam Naga Ramannath

2018-06-01

Centrifugal blowers are widely used turbomachines equipment in all kinds of modern and domestic life. Manufacturing of blowers seldom follow an optimum design solution for individual blower. Although centrifugal blowers are developed as highly efficient machines, design is still based on various empirical and semi empirical rules proposed by fan designers. There are different methodologies used to design the impeller and other components of blowers. The objective of present study is to study explicit design methodologies and tracing unified design to get better design point performance. This unified design methodology is based more on fundamental concepts and minimum assumptions. Parametric study is also carried out for the effect of design parameters on pressure ratio and their interdependency in the design. The code is developed based on a unified design using C programming. Numerical analysis is carried out to check the flow parameters inside the blower. Two blowers, one based on the present design and other on industrial design, are developed with a standard OEM blower manufacturing unit. A comparison of both designs is done based on experimental performance analysis as per IS standard. The results suggest better efficiency and more flow rate for the same pressure head in case of the present design compared with industrial one.

Quality of Diagnosis and Treatment Plans After Using the 'Diagnostic Guideline for Anxiety and Challenging Behaviours' in People with Intellectual Disabilities: A Comparative Multiple Case Study Design.

PubMed

Pruijssers, Addy; van Meijel, Berno; Maaskant, Marian; Keeman, Noortje; van Achterberg, Theo

2016-07-01

People with intellectual disabilities often have a multitude of concurrent problems due to the combination of cognitive impairments, psychiatric disorders (particularly anxiety) and related challenging behaviours. Diagnoses in people with intellectual disabilities are complicated. This study evaluates the quality of the diagnoses and treatment plans after using a guideline that was developed to support professionals in their diagnostic tasks. A comparative multiple case study with an experimental and control condition, applying deductive analyses of diagnoses and treatment plans. The analyses revealed that the number of diagnostic statements and planned treatment actions in the experimental group was significantly larger and more differentiated than in the control condition. In the control group, consequential harm and protective factors were hardly mentioned in diagnoses and treatment plans. Working with the 'Diagnostic Guideline for Anxiety and CB' leads to improved diagnoses and treatment plans compared with care as usual. © 2015 John Wiley & Sons Ltd.