Diagnostic Classification of Eating Disorders in Children and Adolescents: How Does DSM-IV-TR Compare to Empirically-Derived Categories?

ERIC Educational Resources Information Center

Eddy, Kamryn T.; Le Grange, Daniel; Crosby, Ross D.; Hoste, Renee Rienecke; Doyle, Angela Celio; Smyth, Angela; Herzog, David B.

2010-01-01

Objective: The purpose of this study was to empirically derive eating disorder phenotypes in a clinical sample of children and adolescents using latent profile analysis (LPA), and to compare these latent profile (LP) groups to the DSM-IV-TR eating disorder categories. Method: Eating disorder symptom data collected from 401 youth (aged 7 through 19…

An Empirical Review of Research Methodologies and Methods in Creativity Studies (2003-2012)

ERIC Educational Resources Information Center

Long, Haiying

2014-01-01

Based on the data collected from 5 prestigious creativity journals, research methodologies and methods of 612 empirical studies on creativity, published between 2003 and 2012, were reviewed and compared to those in gifted education. Major findings included: (a) Creativity research was predominantly quantitative and psychometrics and experiment…

Conceptions of Giftedness and Expertise Put to the Empirical Test

ERIC Educational Resources Information Center

Harder, Bettina; Vialle, Wilma; Ziegler, Albert

2014-01-01

Recent handbooks of giftedness or expertise propose a plethora of conceptions on the development of excellent performance but, to our knowledge, there are no comparative studies that provide empirical evidence of their validity to guide researchers and practitioners in their adoption of a particular conception. This study sought to close that gap…

Piperacillin-tazobactam vs. imipenem-cilastatin as empirical therapy in hematopoietic stem cell transplantation recipients with febrile neutropenia.

PubMed

Jing, Yu; Li, Jian; Yuan, Lei; Zhao, Xiaoli; Wang, Quanshun; Yu, Li; Zhou, Daobin; Huang, Wenrong

2016-03-01

This randomized, dual-center study compared the efficacy and safety of piperacillin-tazobactam (PTZ) and imipenem-cilastatin (IMP) in hematopoietic stem cell transplantation (HSCT) recipients with febrile neutropenia. HSCT recipients with febrile neutropenia were randomized into two groups receiving either PTZ or IMP as initial empiric antibiotic. Endpoints were defervescence rate after empiric antibiotic for 48 h, success at end of therapy, and side effects. Defervescence within 48 h after empiric antibiotic was observed in 46 patients with PTZ (75.4%) and 59 patients with IMP (95.2%) (p = 0.002). Ten patients (10/46) in the PTZ group and two patients (2/59) in the IMP group switched empiric antibiotics due to recurrent fever (p = 0.005). Success of initial antibiotic with modification was achieved in 34 patients with PTZ (55.7%) and 53 patients with IMP (85.5%) at the end of therapy (p = 0.001). To treat the bacteremia, seven of 10 patients in the PTZ group and one of eight patients in the IMP group needed to switch the empiric antibiotic (p = 0.025). Compared with PTZ, IMP had more gastrointestinal adverse events (p = 0.045). This study demonstrates that IMP had better efficacy than PTZ as an empiric antibiotic for febrile neutropenia in the HSCT setting, but with more gastrointestinal side reactions. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Characterization and effectiveness of pay-for-performance in ophthalmology: a systematic review.

PubMed

Herbst, Tim; Emmert, Martin

2017-06-05

To identify, characterize and compare existing pay-for-performance approaches and their impact on the quality of care and efficiency in ophthalmology. A systematic evidence-based review was conducted. English, French and German written literature published between 2000 and 2015 were searched in the following databases: Medline (via PubMed), NCBI web site, Scopus, Web of Knowledge, Econlit and the Cochrane Library. Empirical as well as descriptive articles were included. Controlled clinical trials, meta-analyses, randomized controlled studies as well as observational studies were included as empirical articles. Systematic characterization of identified pay-for-performance approaches (P4P approaches) was conducted according to the "Model for Implementing and Monitoring Incentives for Quality" (MIMIQ). Methodological quality of empirical articles was assessed according to the Critical Appraisal Skills Programme (CASP) checklists. Overall, 13 relevant articles were included. Eleven articles were descriptive and two articles included empirical analyses. Based on these articles, four different pay-for-performance approaches implemented in the United States were identified. With regard to quality and incentive elements, systematic comparison showed numerous differences between P4P approaches. Empirical studies showed isolated cost or quality effects, while a simultaneous examination of these effects was missing. Research results show that experiences with pay-for-performance approaches in ophthalmology are limited. Identified approaches differ with regard to quality and incentive elements restricting comparability. Two empirical studies are insufficient to draw strong conclusions about the effectiveness and efficiency of these approaches.

Prospective open-label randomized comparative, non-inferiority study of two initial antibiotic strategies for patients with nursing- and healthcare-associated pneumonia: Guideline-concordant therapy versus empiric therapy.

PubMed

Matsuda, Shuichi; Ogasawara, Takashi; Sugimoto, Shunsuke; Kato, Shinpei; Umezawa, Hiroki; Yano, Toshiaki; Kasamatsu, Norio

2016-06-01

The nursing- and healthcare-associated pneumonia guideline, proposed by the Japan Respiratory Society, recommends that patients at risk of exposure to drug-resistant pathogens, classified as treatment category C, be treated with antipseudomonal antibiotics. This study aimed to prove the non-inferiority of empirical therapy in our hospital compared with guideline-concordant therapy. This was a randomized controlled trial conducted from December 2011 to December 2012. Patients were randomized to the Guideline group receiving guideline-concordant therapy, and the Empiric group treated with sulbactam/ampicillin or ceftriaxone. The primary endpoint was in-hospital relapse of pneumonia and mortality within 30 days, with a predefined non-inferiority margin of 10%. The secondary endpoints included duration, adverse effects, and cost of antibiotic therapy. One hundred and eleven patients were assigned to the Guideline group (n = 55) and the Empiric group (n = 56; 3 of which were excluded). The incidence of relapse and death within 30 days was similar in the Guideline and the Empiric groups (31% vs. 26%, risk difference -4.5%, 95% CI -21.5% to 12.5%). While the duration of antibiotic therapy was slightly shorter in the Guideline group than in the Empiric group (7 vs. 8 days), there were no significant differences in adverse effects or cost. The efficacy of empiric therapy was comparable to guideline-concordant therapy, although non-inferiority was not proven. The administration of broad-spectrum antibiotics to patients at risk of exposure to drug-resistant pathogens may not necessarily improve the prognosis. UMIN000006792. Copyright © 2016 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Racial Diversity, Student Religiosity, and School Choice: An Empirical Case Study of Multi-Racial Religious Education

ERIC Educational Resources Information Center

Reichard, Joshua D.

2014-01-01

This article comprises an empirical case study of student religiosity in the context of urban school choice. The purpose of this study was to compare student religiosity in a racially diverse religious private school to determine whether religious faith is a unifying factor across racial categories. Insofar as school choice has been called…

Oseltamivir Treatment for Children with Influenza-Like Illness in China: A Cost-Effectiveness Analysis.

PubMed

Shen, Kunling; Xiong, Tengbin; Tan, Seng Chuen; Wu, Jiuhong

2016-01-01

Influenza is a common viral respiratory infection that causes epidemics and pandemics in the human population. Oseltamivir is a neuraminidase inhibitor-a new class of antiviral therapy for influenza. Although its efficacy and safety have been established, there is uncertainty regarding whether influenza-like illness (ILI) in children is best managed by oseltamivir at the onset of illness, and its cost-effectiveness in children has not been studied in China. To evaluate the cost-effectiveness of post rapid influenza diagnostic test (RIDT) treatment with oseltamivir and empiric treatment with oseltamivir comparing with no antiviral therapy against influenza for children with ILI. We developed a decision-analytic model based on previously published evidence to simulate and evaluate 1-year potential clinical and economic outcomes associated with three managing strategies for children presenting with symptoms of influenza. Model inputs were derived from literature and expert opinion of clinical practice and research in China. Outcome measures included costs and quality-adjusted life year (QALY). All the interventions were compared with incremental cost-effectiveness ratios (ICER). In base case analysis, empiric treatment with oseltamivir consistently produced the greatest gains in QALY. When compared with no antiviral therapy, the empiric treatment with oseltamivir strategy is very cost effective with an ICER of RMB 4,438. When compared with the post RIDT treatment with oseltamivir, the empiric treatment with oseltamivir strategy is dominant. Probabilistic sensitivity analysis projected that there is a 100% probability that empiric oseltamivir treatment would be considered as a very cost-effective strategy compared to the no antiviral therapy, according to the WHO recommendations for cost-effectiveness thresholds. The same was concluded with 99% probability for empiric oseltamivir treatment being a very cost-effective strategy compared to the post RIDT treatment with oseltamivir. In the Chinese setting of current health system, our modelling based simulation analysis suggests that empiric treatment with oseltamivir to be a cost-saving and very cost-effective strategy in managing children with ILI.

The Myth of Social Class and Criminality: An Empirical Assessment of the Empirical Evidence.

ERIC Educational Resources Information Center

Tittle, Charles R.; And Others

1978-01-01

Thirty-five studies examining the relationship between social class and crime/delinquency are reduced to comparable statistics using as units of analysis instances where the relationship was studied for specific categories of age, sex, race, place of residence, data type, or offense. Findings from 363 instances are summarized and patterns are…

Empirical Assessment of Effect of Publication Bias on a Meta-Analysis of Validity Studies on University Matriculation Examinations in Nigeria

ERIC Educational Resources Information Center

Adeyemo, Emily Oluseyi

2012-01-01

This study examined the impact of publication bias on a meta-analysis of empirical studies on validity of University Matriculation Examinations in Nigeria with a view to determine the level of difference between published and unpublished articles. Specifically, the design was an ex-post facto, a causal comparative design. The sample size consisted…

Using ERP and WfM Systems for Implementing Business Processes: An Empirical Study

NASA Astrophysics Data System (ADS)

Aversano, Lerina; Tortorella, Maria

Software systems mainly considered from enterprises for dealing with a business process automation belong to the following two categories: Workflow Management Systems (WfMS) and Enterprise Resource Planning (ERP) systems. The wider diffusion of ERP systems tends to favourite this solution, but there are several limitations of most ERP systems for automating business processes. This paper reports an empirical study aiming at comparing the ability of implementing business processes of ERP systems and WfMSs. Two different case studies have been considered in the empirical study. It evaluates and analyses the correctness and completeness of the process models implemented by using ERP and WfM systems.

Analytical Investigation and Improvement of Performance of a Proton Exchange Membrane (Pem) Fuel Cell in Mobile Applications

NASA Astrophysics Data System (ADS)

Khazaee, I.

2015-05-01

In this study, the performance of a proton exchange membrane fuel cell in mobile applications is investigated analytically. At present the main use and advantages of fuel cells impact particularly strongly on mobile applications such as vehicles, mobile computers and mobile telephones. Some external parameters such as the cell temperature (Tcell ) , operating pressure of gases (P) and air stoichiometry (λair ) affect the performance and voltage losses in the PEM fuel cell. Because of the existence of many theoretical, empirical and semi-empirical models of the PEM fuel cell, it is necessary to compare the accuracy of these models. But theoretical models that are obtained from thermodynamic and electrochemical approach, are very exact but complex, so it would be easier to use the empirical and smi-empirical models in order to forecast the fuel cell system performance in many applications such as mobile applications. The main purpose of this study is to obtain the semi-empirical relation of a PEM fuel cell with the least voltage losses. Also, the results are compared with the existing experimental results in the literature and a good agreement is seen.

Comparing and Contrasting Consensus versus Empirical Domains

PubMed Central

Jason, Leonard A.; Kot, Bobby; Sunnquist, Madison; Brown, Abigail; Reed, Jordan; Furst, Jacob; Newton, Julia L.; Strand, Elin Bolle; Vernon, Suzanne D.

2015-01-01

Background Since the publication of the CFS case definition [1], there have been a number of other criteria proposed including the Canadian Consensus Criteria [2] and the Myalgic Encephalomyelitis: International Consensus Criteria. [3] Purpose The current study compared these domains that were developed through consensus methods to one obtained through more empirical approaches using factor analysis. Methods Using data mining, we compared and contrasted fundamental features of consensus-based criteria versus empirical latent factors. In general, these approaches found the domain of Fatigue/Post-exertional malaise as best differentiating patients from controls. Results Findings indicated that the Fukuda et al. criteria had the worst sensitivity and specificity. Conclusions These outcomes might help both theorists and researchers better determine which fundamental domains to be used for the case definition. PMID:26977374

Comparison of safety effect estimates obtained from empirical Bayes before-after study, propensity scores-potential outcomes framework, and regression model with cross-sectional data.

PubMed

Wood, Jonathan S; Donnell, Eric T; Porter, Richard J

2015-02-01

A variety of different study designs and analysis methods have been used to evaluate the performance of traffic safety countermeasures. The most common study designs and methods include observational before-after studies using the empirical Bayes method and cross-sectional studies using regression models. The propensity scores-potential outcomes framework has recently been proposed as an alternative traffic safety countermeasure evaluation method to address the challenges associated with selection biases that can be part of cross-sectional studies. Crash modification factors derived from the application of all three methods have not yet been compared. This paper compares the results of retrospective, observational evaluations of a traffic safety countermeasure using both before-after and cross-sectional study designs. The paper describes the strengths and limitations of each method, focusing primarily on how each addresses site selection bias, which is a common issue in observational safety studies. The Safety Edge paving technique, which seeks to mitigate crashes related to roadway departure events, is the countermeasure used in the present study to compare the alternative evaluation methods. The results indicated that all three methods yielded results that were consistent with each other and with previous research. The empirical Bayes results had the smallest standard errors. It is concluded that the propensity scores with potential outcomes framework is a viable alternative analysis method to the empirical Bayes before-after study. It should be considered whenever a before-after study is not possible or practical. Copyright © 2014 Elsevier Ltd. All rights reserved.

GPS-Derived Precipitable Water Compared with the Air Force Weather Agency’s MM5 Model Output

DTIC Science & Technology

2002-03-26

and less then 100 sensors are available throughout Europe . While the receiver density is currently comparable to the upper-air sounding network...profiles from 38 upper air sites throughout Europe . Based on these empirical formulae and simplifications, Bevis (1992) has determined that the error...Alaska using Bevis’ (1992) empirical correlation based on 8718 radiosonde calculations over 2 years. Other studies have been conducted in Europe and

AN ATTEMPT TO FIND AN A PRIORI MEASURE OF STEP SIZE. COMPARATIVE STUDIES OF PRINCIPLES FOR PROGRAMMING MATHEMATICS IN AUTOMATED INSTRUCTION, TECHNICAL REPORT NO. 13.

ERIC Educational Resources Information Center

ROSEN, ELLEN F.; STOLUROW, LAWRENCE M.

IN ORDER TO FIND A GOOD PREDICTOR OF EMPIRICAL DIFFICULTY, AN OPERATIONAL DEFINITION OF STEP SIZE, TEN PROGRAMER-JUDGES RATED CHANGE IN COMPLEXITY IN TWO VERSIONS OF A MATHEMATICS PROGRAM, AND THESE RATINGS WERE THEN COMPARED WITH MEASURES OF EMPIRICAL DIFFICULTY OBTAINED FROM STUDENT RESPONSE DATA. THE TWO VERSIONS, A 54 FRAME BOOKLET AND A 35…

Feynman perturbation expansion for the price of coupon bond options and swaptions in quantum finance. II. Empirical

NASA Astrophysics Data System (ADS)

Baaquie, Belal E.; Liang, Cui

2007-01-01

The quantum finance pricing formulas for coupon bond options and swaptions derived by Baaquie [Phys. Rev. E 75, 016703 (2006)] are reviewed. We empirically study the swaption market and propose an efficient computational procedure for analyzing the data. Empirical results of the swaption price, volatility, and swaption correlation are compared with the predictions of quantum finance. The quantum finance model generates the market swaption price to over 90% accuracy.

Feynman perturbation expansion for the price of coupon bond options and swaptions in quantum finance. II. Empirical.

PubMed

Baaquie, Belal E; Liang, Cui

2007-01-01

The quantum finance pricing formulas for coupon bond options and swaptions derived by Baaquie [Phys. Rev. E 75, 016703 (2006)] are reviewed. We empirically study the swaption market and propose an efficient computational procedure for analyzing the data. Empirical results of the swaption price, volatility, and swaption correlation are compared with the predictions of quantum finance. The quantum finance model generates the market swaption price to over 90% accuracy.

Comparison of empirical estimate of clinical pretest probability with the Wells score for diagnosis of deep vein thrombosis.

PubMed

Wang, Bo; Lin, Yin; Pan, Fu-shun; Yao, Chen; Zheng, Zi-Yu; Cai, Dan; Xu, Xiang-dong

2013-01-01

Wells score has been validated for estimation of pretest probability in patients with suspected deep vein thrombosis (DVT). In clinical practice, many clinicians prefer to use empirical estimation rather than Wells score. However, which method is better to increase the accuracy of clinical evaluation is not well understood. Our present study compared empirical estimation of pretest probability with the Wells score to investigate the efficiency of empirical estimation in the diagnostic process of DVT. Five hundred and fifty-five patients were enrolled in this study. One hundred and fifty patients were assigned to examine the interobserver agreement for Wells score between emergency and vascular clinicians. The other 405 patients were assigned to evaluate the pretest probability of DVT on the basis of the empirical estimation and Wells score, respectively, and plasma D-dimer levels were then determined in the low-risk patients. All patients underwent venous duplex scans and had a 45-day follow up. Weighted Cohen's κ value for interobserver agreement between emergency and vascular clinicians of the Wells score was 0.836. Compared with Wells score evaluation, empirical assessment increased the sensitivity, specificity, Youden's index, positive likelihood ratio, and positive and negative predictive values, but decreased negative likelihood ratio. In addition, the appropriate D-dimer cutoff value based on Wells score was 175 μg/l and 108 patients were excluded. Empirical assessment increased the appropriate D-dimer cutoff point to 225 μg/l and 162 patients were ruled out. Our findings indicated that empirical estimation not only improves D-dimer assay efficiency for exclusion of DVT but also increases clinical judgement accuracy in the diagnosis of DVT.

Empirical and targeted therapy of candidemia with fluconazole versus echinocandins: a propensity score-derived analysis of a population-based, multicentre prospective cohort.

PubMed

López-Cortés, L E; Almirante, B; Cuenca-Estrella, M; Garnacho-Montero, J; Padilla, B; Puig-Asensio, M; Ruiz-Camps, I; Rodríguez-Baño, J

2016-08-01

We compared the clinical efficacy of fluconazole and echinocandins in the treatment of candidemia in real practice. The CANDIPOP study is a prospective, population-based cohort study on candidemia carried out between May 2010 and April 2011 in 29 Spanish hospitals. Using strict inclusion criteria, we separately compared the impact of empirical and targeted therapy with fluconazole or echinocandins on 30-day mortality. Cox regression, including a propensity score (PS) for receiving echinocandins, stratified analysis on the PS quartiles and PS-based matched analyses, were performed. The empirical and targeted therapy cohorts comprised 316 and 421 cases, respectively; 30-day mortality was 18.7% with fluconazole and 33.9% with echinocandins (p 0.02) in the empirical therapy group and 19.8% with fluconazole and 27.7% with echinocandins (p 0.06) in the targeted therapy group. Multivariate Cox regression analysis including PS showed that empirical therapy with fluconazole was associated with better prognosis (adjusted hazard ratio 0.38; 95% confidence interval 0.17-0.81; p 0.01); no differences were found within each PS quartile or in cases matched according to PS. Targeted therapy with fluconazole did not show a significant association with mortality in the Cox regression analysis (adjusted hazard ratio 0.77; 95% confidence interval 0.41-1.46; p 0.63), in the PS quartiles or in PS-matched cases. The results were similar among patients with severe sepsis and septic shock. Empirical or targeted treatment with fluconazole was not associated with increased 30-day mortality compared to echinocandins among adults with candidemia. Copyright © 2016 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Facebook's Effect on Learning in Higher Education: An Empirical Investigation

ERIC Educational Resources Information Center

Duncan, Doris G.; Barczyk, Casimir C.

2016-01-01

Due in part to its widespread acceptance, Facebook has been adopted as a tool for higher education courses. Proponents claim that Facebook-enhanced courses facilitate an increased community of practice, sense of learning and sense of connectedness compared to non-enhanced courses. This empirical study uses a survey methodology in an independent…

Transition mixing study empirical model report

NASA Technical Reports Server (NTRS)

Srinivasan, R.; White, C.

1988-01-01

The empirical model developed in the NASA Dilution Jet Mixing Program has been extended to include the curvature effects of transition liners. This extension is based on the results of a 3-D numerical model generated under this contract. The empirical model results agree well with the numerical model results for all tests cases evaluated. The empirical model shows faster mixing rates compared to the numerical model. Both models show drift of jets toward the inner wall of a turning duct. The structure of the jets from the inner wall does not exhibit the familiar kidney-shaped structures observed for the outer wall jets or for jets injected in rectangular ducts.

Empirical expression for DC magnetization curve of immobilized magnetic nanoparticles for use in biomedical applications

NASA Astrophysics Data System (ADS)

Elrefai, Ahmed L.; Sasayama, Teruyoshi; Yoshida, Takashi; Enpuku, Keiji

2018-05-01

We studied the magnetization (M-H) curve of immobilized magnetic nanoparticles (MNPs) used for biomedical applications. First, we performed numerical simulation on the DC M-H curve over a wide range of MNPs parameters. Based on the simulation results, we obtained an empirical expression for DC M-H curve. The empirical expression was compared with the measured M-H curves of various MNP samples, and quantitative agreements were obtained between them. We can also estimate the basic parameters of MNP from the comparison. Therefore, the empirical expression is useful for analyzing the M-H curve of immobilized MNPs for specific biomedical applications.

Improved inland water levels from SAR altimetry using novel empirical and physical retrackers

NASA Astrophysics Data System (ADS)

Villadsen, Heidi; Deng, Xiaoli; Andersen, Ole B.; Stenseng, Lars; Nielsen, Karina; Knudsen, Per

2016-06-01

Satellite altimetry has proven a valuable resource of information on river and lake levels where in situ data are sparse or non-existent. In this study several new methods for obtaining stable inland water levels from CryoSat-2 Synthetic Aperture Radar (SAR) altimetry are presented and evaluated. In addition, the possible benefits from combining physical and empirical retrackers are investigated. The retracking methods evaluated in this paper include the physical SAR Altimetry MOde Studies and Applications (SAMOSA3) model, a traditional subwaveform threshold retracker, the proposed Multiple Waveform Persistent Peak (MWaPP) retracker, and a method combining the physical and empirical retrackers. Using a physical SAR waveform retracker over inland water has not been attempted before but shows great promise in this study. The evaluation is performed for two medium-sized lakes (Lake Vänern in Sweden and Lake Okeechobee in Florida), and in the Amazon River in Brazil. Comparing with in situ data shows that using the SAMOSA3 retracker generally provides the lowest root-mean-squared-errors (RMSE), closely followed by the MWaPP retracker. For the empirical retrackers, the RMSE values obtained when comparing with in situ data in Lake Vänern and Lake Okeechobee are in the order of 2-5 cm for well-behaved waveforms. Combining the physical and empirical retrackers did not offer significantly improved mean track standard deviations or RMSEs. Based on these studies, it is suggested that future SAR derived water levels are obtained using the SAMOSA3 retracker whenever information about other physical properties apart from range is desired. Otherwise we suggest using the empirical MWaPP retracker described in this paper, which is both easy to implement, computationally efficient, and gives a height estimate for even the most contaminated waveforms.

A classification of ecological boundaries

USGS Publications Warehouse

Strayer, D.L.; Power, M.E.; Fagan, W.F.; Pickett, S.T.A.; Belnap, J.

2003-01-01

Ecologists use the term boundary to refer to a wide range of real and conceptual structures. Because imprecise terminology may impede the search for general patterns and theories about ecological boundaries, we present a classification of the attributes of ecological boundaries to aid in communication and theory development. Ecological boundaries may differ in their origin and maintenance, their spatial structure, their function, and their temporal dynamics. A classification system based on these attributes should help ecologists determine whether boundaries are truly comparable. This system can be applied when comparing empirical studies, comparing theories, and testing theoretical predictions against empirical results.

Biomarker-based strategy for early discontinuation of empirical antifungal treatment in critically ill patients: a randomized controlled trial.

PubMed

Rouzé, Anahita; Loridant, Séverine; Poissy, Julien; Dervaux, Benoit; Sendid, Boualem; Cornu, Marjorie; Nseir, Saad

2017-11-01

The aim of this study was to determine the impact of a biomarker-based strategy on early discontinuation of empirical antifungal treatment. Prospective randomized controlled single-center unblinded study, performed in a mixed ICU. A total of 110 patients were randomly assigned to a strategy in which empirical antifungal treatment duration was determined by (1,3)-β-D-glucan, mannan, and anti-mannan serum assays, performed on day 0 and day 4; or to a routine care strategy, based on international guidelines, which recommend 14 days of treatment. In the biomarker group, early stop recommendation was determined using an algorithm based on the results of biomarkers. The primary outcome was the percentage of survivors discontinuing empirical antifungal treatment early, defined as a discontinuation strictly before day 7. A total of 109 patients were analyzed (one patient withdraw consent). Empirical antifungal treatment was discontinued early in 29 out of 54 patients in the biomarker strategy group, compared with one patient out of 55 in the routine strategy group [54% vs 2%, p < 0.001, OR (95% CI) 62.6 (8.1-486)]. Total duration of antifungal treatment was significantly shorter in the biomarker strategy compared with routine strategy [median (IQR) 6 (4-13) vs 13 (12-14) days, p < 0.0001). No significant difference was found in the percentage of patients with subsequent proven invasive Candida infection, mechanical ventilation-free days, length of ICU stay, cost, and ICU mortality between the two study groups. The use of a biomarker-based strategy increased the percentage of early discontinuation of empirical antifungal treatment among critically ill patients with suspected invasive Candida infection. These results confirm previous findings suggesting that early discontinuation of empirical antifungal treatment had no negative impact on outcome. However, further studies are needed to confirm the safety of this strategy. This trial was registered at ClinicalTrials.gov, NCT02154178.

Empirical likelihood-based tests for stochastic ordering

PubMed Central

BARMI, HAMMOU EL; MCKEAGUE, IAN W.

2013-01-01

This paper develops an empirical likelihood approach to testing for the presence of stochastic ordering among univariate distributions based on independent random samples from each distribution. The proposed test statistic is formed by integrating a localized empirical likelihood statistic with respect to the empirical distribution of the pooled sample. The asymptotic null distribution of this test statistic is found to have a simple distribution-free representation in terms of standard Brownian bridge processes. The approach is used to compare the lengths of rule of Roman Emperors over various historical periods, including the “decline and fall” phase of the empire. In a simulation study, the power of the proposed test is found to improve substantially upon that of a competing test due to El Barmi and Mukerjee. PMID:23874142

Increasing Functional Communication in Non-Speaking Preschool Children: Comparison of PECS and VOCA

ERIC Educational Resources Information Center

Bock, Stacey Jones; Stoner, Julia B.; Beck, Ann R.; Hanley, Laurie; Prochnow, Jessica

2005-01-01

For individuals who have complex communication needs and for the interventionists who work with them, the collection of empirically derived data that support the use of an intervention approach is critical. The purposes of this study were to continue building an empirically derived base of support for, and to compare the relative effectiveness of…

Indigenous People and Poverty in Latin America: An Empirical Analysis. World Bank Regional and Sectoral Studies.

ERIC Educational Resources Information Center

Psacharopoulos, George, Ed.; Patrinos, Harry Anthony, Ed.

The indigenous peoples of Latin America live in conditions of extreme poverty. This book uses empirical data from national survey sources to determine the extent of poverty among Latin American indigenous populations; to compare indigenous and nonindigenous populations with regard to socioeconomic status, living conditions, educational attainment,…

Determination of errors in derived magnetic field directions in geosynchronous orbit: results from a statistical approach

NASA Astrophysics Data System (ADS)

Chen, Yue; Cunningham, Gregory; Henderson, Michael

2016-09-01

This study aims to statistically estimate the errors in local magnetic field directions that are derived from electron directional distributions measured by Los Alamos National Laboratory geosynchronous (LANL GEO) satellites. First, by comparing derived and measured magnetic field directions along the GEO orbit to those calculated from three selected empirical global magnetic field models (including a static Olson and Pfitzer 1977 quiet magnetic field model, a simple dynamic Tsyganenko 1989 model, and a sophisticated dynamic Tsyganenko 2001 storm model), it is shown that the errors in both derived and modeled directions are at least comparable. Second, using a newly developed proxy method as well as comparing results from empirical models, we are able to provide for the first time circumstantial evidence showing that derived magnetic field directions should statistically match the real magnetic directions better, with averaged errors < ˜ 2°, than those from the three empirical models with averaged errors > ˜ 5°. In addition, our results suggest that the errors in derived magnetic field directions do not depend much on magnetospheric activity, in contrast to the empirical field models. Finally, as applications of the above conclusions, we show examples of electron pitch angle distributions observed by LANL GEO and also take the derived magnetic field directions as the real ones so as to test the performance of empirical field models along the GEO orbits, with results suggesting dependence on solar cycles as well as satellite locations. This study demonstrates the validity and value of the method that infers local magnetic field directions from particle spin-resolved distributions.

Determination of errors in derived magnetic field directions in geosynchronous orbit: results from a statistical approach

DOE PAGES

Chen, Yue; Cunningham, Gregory; Henderson, Michael

2016-09-21

Our study aims to statistically estimate the errors in local magnetic field directions that are derived from electron directional distributions measured by Los Alamos National Laboratory geosynchronous (LANL GEO) satellites. First, by comparing derived and measured magnetic field directions along the GEO orbit to those calculated from three selected empirical global magnetic field models (including a static Olson and Pfitzer 1977 quiet magnetic field model, a simple dynamic Tsyganenko 1989 model, and a sophisticated dynamic Tsyganenko 2001 storm model), it is shown that the errors in both derived and modeled directions are at least comparable. Furthermore, using a newly developedmore » proxy method as well as comparing results from empirical models, we are able to provide for the first time circumstantial evidence showing that derived magnetic field directions should statistically match the real magnetic directions better, with averaged errors < ~2°, than those from the three empirical models with averaged errors > ~5°. In addition, our results suggest that the errors in derived magnetic field directions do not depend much on magnetospheric activity, in contrast to the empirical field models. Finally, as applications of the above conclusions, we show examples of electron pitch angle distributions observed by LANL GEO and also take the derived magnetic field directions as the real ones so as to test the performance of empirical field models along the GEO orbits, with results suggesting dependence on solar cycles as well as satellite locations. Finally, this study demonstrates the validity and value of the method that infers local magnetic field directions from particle spin-resolved distributions.« less

Determination of errors in derived magnetic field directions in geosynchronous orbit: results from a statistical approach

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

Chen, Yue; Cunningham, Gregory; Henderson, Michael

Our study aims to statistically estimate the errors in local magnetic field directions that are derived from electron directional distributions measured by Los Alamos National Laboratory geosynchronous (LANL GEO) satellites. First, by comparing derived and measured magnetic field directions along the GEO orbit to those calculated from three selected empirical global magnetic field models (including a static Olson and Pfitzer 1977 quiet magnetic field model, a simple dynamic Tsyganenko 1989 model, and a sophisticated dynamic Tsyganenko 2001 storm model), it is shown that the errors in both derived and modeled directions are at least comparable. Furthermore, using a newly developedmore » proxy method as well as comparing results from empirical models, we are able to provide for the first time circumstantial evidence showing that derived magnetic field directions should statistically match the real magnetic directions better, with averaged errors < ~2°, than those from the three empirical models with averaged errors > ~5°. In addition, our results suggest that the errors in derived magnetic field directions do not depend much on magnetospheric activity, in contrast to the empirical field models. Finally, as applications of the above conclusions, we show examples of electron pitch angle distributions observed by LANL GEO and also take the derived magnetic field directions as the real ones so as to test the performance of empirical field models along the GEO orbits, with results suggesting dependence on solar cycles as well as satellite locations. Finally, this study demonstrates the validity and value of the method that infers local magnetic field directions from particle spin-resolved distributions.« less

A preliminary study of mechanistic approach in pavement design to accommodate climate change effects

NASA Astrophysics Data System (ADS)

Harnaeni, S. R.; Pramesti, F. P.; Budiarto, A.; Setyawan, A.

2018-03-01

Road damage is caused by some factors, including climate changes, overload, and inappropriate procedure for material and development process. Meanwhile, climate change is a phenomenon which cannot be avoided. The effects observed include air temperature rise, sea level rise, rainfall changes, and the intensity of extreme weather phenomena. Previous studies had shown the impacts of climate changes on road damage. Therefore, several measures to anticipate the damage should be considered during the planning and construction in order to reduce the cost of road maintenance. There are three approaches generally applied in the design of flexible pavement thickness, namely mechanistic approach, mechanistic-empirical (ME) approach and empirical approach. The advantages of applying mechanistic approach or mechanistic-empirical (ME) approaches are its efficiency and reliability in the design of flexible pavement thickness as well as its capacity to accommodate climate changes in compared to empirical approach. However, generally, the design of flexible pavement thickness in Indonesia still applies empirical approach. This preliminary study aimed to emphasize the importance of the shifting towards a mechanistic approach in the design of flexible pavement thickness.

Does Gene Tree Discordance Explain the Mismatch between Macroevolutionary Models and Empirical Patterns of Tree Shape and Branching Times?

PubMed Central

Stadler, Tanja; Degnan, James H.; Rosenberg, Noah A.

2016-01-01

Classic null models for speciation and extinction give rise to phylogenies that differ in distribution from empirical phylogenies. In particular, empirical phylogenies are less balanced and have branching times closer to the root compared to phylogenies predicted by common null models. This difference might be due to null models of the speciation and extinction process being too simplistic, or due to the empirical datasets not being representative of random phylogenies. A third possibility arises because phylogenetic reconstruction methods often infer gene trees rather than species trees, producing an incongruity between models that predict species tree patterns and empirical analyses that consider gene trees. We investigate the extent to which the difference between gene trees and species trees under a combined birth–death and multispecies coalescent model can explain the difference in empirical trees and birth–death species trees. We simulate gene trees embedded in simulated species trees and investigate their difference with respect to tree balance and branching times. We observe that the gene trees are less balanced and typically have branching times closer to the root than the species trees. Empirical trees from TreeBase are also less balanced than our simulated species trees, and model gene trees can explain an imbalance increase of up to 8% compared to species trees. However, we see a much larger imbalance increase in empirical trees, about 100%, meaning that additional features must also be causing imbalance in empirical trees. This simulation study highlights the necessity of revisiting the assumptions made in phylogenetic analyses, as these assumptions, such as equating the gene tree with the species tree, might lead to a biased conclusion. PMID:26968785

Assessing differential expression in two-color microarrays: a resampling-based empirical Bayes approach.

PubMed

Li, Dongmei; Le Pape, Marc A; Parikh, Nisha I; Chen, Will X; Dye, Timothy D

2013-01-01

Microarrays are widely used for examining differential gene expression, identifying single nucleotide polymorphisms, and detecting methylation loci. Multiple testing methods in microarray data analysis aim at controlling both Type I and Type II error rates; however, real microarray data do not always fit their distribution assumptions. Smyth's ubiquitous parametric method, for example, inadequately accommodates violations of normality assumptions, resulting in inflated Type I error rates. The Significance Analysis of Microarrays, another widely used microarray data analysis method, is based on a permutation test and is robust to non-normally distributed data; however, the Significance Analysis of Microarrays method fold change criteria are problematic, and can critically alter the conclusion of a study, as a result of compositional changes of the control data set in the analysis. We propose a novel approach, combining resampling with empirical Bayes methods: the Resampling-based empirical Bayes Methods. This approach not only reduces false discovery rates for non-normally distributed microarray data, but it is also impervious to fold change threshold since no control data set selection is needed. Through simulation studies, sensitivities, specificities, total rejections, and false discovery rates are compared across the Smyth's parametric method, the Significance Analysis of Microarrays, and the Resampling-based empirical Bayes Methods. Differences in false discovery rates controls between each approach are illustrated through a preterm delivery methylation study. The results show that the Resampling-based empirical Bayes Methods offer significantly higher specificity and lower false discovery rates compared to Smyth's parametric method when data are not normally distributed. The Resampling-based empirical Bayes Methods also offers higher statistical power than the Significance Analysis of Microarrays method when the proportion of significantly differentially expressed genes is large for both normally and non-normally distributed data. Finally, the Resampling-based empirical Bayes Methods are generalizable to next generation sequencing RNA-seq data analysis.

Forest canopy effects on snow accumulation and ablation: an integrative review of empirical results

Treesearch

Andres Varhola; Nicholas C. Coops; Markus Weiler; R. Dan Moore

2010-01-01

The past century has seen significant research comparing snow accumulation and ablation in forested and open sites. In this review we compile and standardize the results of previous empirical studies to generate statistical relations between changes in forest cover and the associated changes in snow accumulation and ablation rate. The analysis drew upon 33 articles...

Freedom from Racial Barriers: The Empirical Evidence on Vouchers and Segregation. School Choice Issues in Depth

ERIC Educational Resources Information Center

Forster, Greg

2006-01-01

This report collects the results of all available studies using valid empirical methods to compare segregation in public and private schools, both in general and in the context of school voucher programs. Examining the widespread claims that private schools have high segregation levels and vouchers will lead to greater segregation, this report…

An Evaluation of Empirical Bayes's Estimation of Value-Added Teacher Performance Measures

ERIC Educational Resources Information Center

Guarino, Cassandra M.; Maxfield, Michelle; Reckase, Mark D.; Thompson, Paul N.; Wooldridge, Jeffrey M.

2015-01-01

Empirical Bayes's (EB) estimation has become a popular procedure used to calculate teacher value added, often as a way to make imprecise estimates more reliable. In this article, we review the theory of EB estimation and use simulated and real student achievement data to study the ability of EB estimators to properly rank teachers. We compare the…

Do People Overestimate Their Information Literacy Skills? A Systematic Review of Empirical Evidence on the Dunning-Kruger Effect

ERIC Educational Resources Information Center

Mahmood, Khalid

2016-01-01

This systematic review has analyzed 53 English language studies that assessed and compared peoples' self-reported and demonstrated information literacy (IL) skills. The objective was to collect empirical evidence on the existence of Dunning-Kruger Effect in the area of information literacy. The findings clearly show that this theory works in this…

An Empirical Method for Deriving Grade Equivalence for University Entrance Qualifications: An Application to A Levels and the International Baccalaureate

ERIC Educational Resources Information Center

Green, Francis; Vignoles, Anna

2012-01-01

We present a method to compare different qualifications for entry to higher education by studying students' subsequent performance. Using this method for students holding either the International Baccalaureate (IB) or A-levels gaining their degrees in 2010, we estimate an "empirical" equivalence scale between IB grade points and UCAS…

An empirically-based model for the lift coefficients of twisted airfoils with leading-edge tubercles

NASA Astrophysics Data System (ADS)

Ni, Zao; Su, Tsung-chow; Dhanak, Manhar

2018-04-01

Experimental data for untwisted airfoils are utilized to propose a model for predicting the lift coefficients of twisted airfoils with leading-edge tubercles. The effectiveness of the empirical model is verified through comparison with results of a corresponding computational fluid-dynamic (CFD) study. The CFD study is carried out for both twisted and untwisted airfoils with tubercles, the latter shown to compare well with available experimental data. Lift coefficients of twisted airfoils predicted from the proposed empirically-based model match well with the corresponding coefficients determined using the verified CFD study. Flow details obtained from the latter provide better insight into the underlying mechanism and behavior at stall of twisted airfoils with leading edge tubercles.

Professionalism: A Comparative Case Study of Teachers, Nurses, and Social Workers

ERIC Educational Resources Information Center

Bair, Mary Antony

2016-01-01

While there are numerous calls to enhance the professionalism of teachers, there is little empirical research in the United States that examines educators' understanding of the concept. This comparative case study compared the conceptualisation of professionalism by faculty and students in a college of education vis-à-vis the conceptualisation of…

Infants under two months of age with urinary tract infections are showing increasing resistance to empirical and oral antibiotics.

PubMed

Segal, Zvi; Cohen, Matan J; Engelhard, Dan; Tenenbaum, Ariel; Simckes, Ari M; Benenson, Shmuel; Stepensky, Polina; Averbuch, Diana

2016-04-01

Data on antimicrobial resistance in uropathogens in infants up to the age of three months are limited. This study characterised resistance patterns in Gram-negative uropathogens in infants up to the age of two months. Previously healthy young infants with urinary tract infections (UTIs) were studied retrospectively. Antimicrobial susceptibility was evaluated. Multidrug resistance (MDR) was defined as resistance to at least three antibiotic classes. Clinical, laboratory and outcome data were compared between infants with UTIs caused by bacteria sensitive and resistant to empirical and to oral therapy. We evaluated 306 UTI episodes with 314 pathogens. The following resistance rates were observed: ampicillin 73.7%, cefazoline 22.1%, ampicillin/clavulanate 21.8%, cefuroxime 7.8%, gentamicin 7%; MDR 11.8%; resistant to empirical treatment 7.3% and resistant to available oral antibiotics 8.6%. Our study showed that pathogens resistant to empirical and oral therapy were more frequently isolated in non-Jewish (Arab) infants and in those of ≥30 days of age. Resistance to empirical treatment and oral antibiotics also resulted in longer mean hospital stays. Resistance to antibiotics challenges empirical therapy and compromises oral treatment options in young infants with UTIs. Antimicrobial resistance patterns should be monitored in infants to determine appropriate empirical antibiotic therapy protocols. ©2015 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

A comparison of entropy balance and probability weighting methods to generalize observational cohorts to a population: a simulation and empirical example.

PubMed

Harvey, Raymond A; Hayden, Jennifer D; Kamble, Pravin S; Bouchard, Jonathan R; Huang, Joanna C

2017-04-01

We compared methods to control bias and confounding in observational studies including inverse probability weighting (IPW) and stabilized IPW (sIPW). These methods often require iteration and post-calibration to achieve covariate balance. In comparison, entropy balance (EB) optimizes covariate balance a priori by calibrating weights using the target's moments as constraints. We measured covariate balance empirically and by simulation by using absolute standardized mean difference (ASMD), absolute bias (AB), and root mean square error (RMSE), investigating two scenarios: the size of the observed (exposed) cohort exceeds the target (unexposed) cohort and vice versa. The empirical application weighted a commercial health plan cohort to a nationally representative National Health and Nutrition Examination Survey target on the same covariates and compared average total health care cost estimates across methods. Entropy balance alone achieved balance (ASMD ≤ 0.10) on all covariates in simulation and empirically. In simulation scenario I, EB achieved the lowest AB and RMSE (13.64, 31.19) compared with IPW (263.05, 263.99) and sIPW (319.91, 320.71). In scenario II, EB outperformed IPW and sIPW with smaller AB and RMSE. In scenarios I and II, EB achieved the lowest mean estimate difference from the simulated population outcome ($490.05, $487.62) compared with IPW and sIPW, respectively. Empirically, only EB differed from the unweighted mean cost indicating IPW, and sIPW weighting was ineffective. Entropy balance demonstrated the bias-variance tradeoff achieving higher estimate accuracy, yet lower estimate precision, compared with IPW methods. EB weighting required no post-processing and effectively mitigated observed bias and confounding. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

An empirical Bayes method for updating inferences in analysis of quantitative trait loci using information from related genome scans.

PubMed

Zhang, Kui; Wiener, Howard; Beasley, Mark; George, Varghese; Amos, Christopher I; Allison, David B

2006-08-01

Individual genome scans for quantitative trait loci (QTL) mapping often suffer from low statistical power and imprecise estimates of QTL location and effect. This lack of precision yields large confidence intervals for QTL location, which are problematic for subsequent fine mapping and positional cloning. In prioritizing areas for follow-up after an initial genome scan and in evaluating the credibility of apparent linkage signals, investigators typically examine the results of other genome scans of the same phenotype and informally update their beliefs about which linkage signals in their scan most merit confidence and follow-up via a subjective-intuitive integration approach. A method that acknowledges the wisdom of this general paradigm but formally borrows information from other scans to increase confidence in objectivity would be a benefit. We developed an empirical Bayes analytic method to integrate information from multiple genome scans. The linkage statistic obtained from a single genome scan study is updated by incorporating statistics from other genome scans as prior information. This technique does not require that all studies have an identical marker map or a common estimated QTL effect. The updated linkage statistic can then be used for the estimation of QTL location and effect. We evaluate the performance of our method by using extensive simulations based on actual marker spacing and allele frequencies from available data. Results indicate that the empirical Bayes method can account for between-study heterogeneity, estimate the QTL location and effect more precisely, and provide narrower confidence intervals than results from any single individual study. We also compared the empirical Bayes method with a method originally developed for meta-analysis (a closely related but distinct purpose). In the face of marked heterogeneity among studies, the empirical Bayes method outperforms the comparator.

Implications of alternative field-sampling designs on Landsat-based mapping of stand age and carbon stocks in Oregon forests

Treesearch

Maureen V. Duane; Warren B. Cohen; John L. Campbell; Tara Hudiburg; David P. Turner; Dale Weyermann

2010-01-01

Empirical models relating forest attributes to remotely sensed metrics are widespread in the literature and underpin many of our efforts to map forest structure across complex landscapes. In this study we compared empirical models relating Landsat reflectance to forest age across Oregon using two alternate sets of ground data: one from a large (n ~ 1500) systematic...

An empirical test of Maslow's theory of need hierarchy using hologeistic comparison by statistical sampling.

PubMed

Davis-Sharts, J

1986-10-01

Maslow's hierarchy of basic human needs provides a major theoretical framework in nursing science. The purpose of this study was to empirically test Maslow's need theory, specifically at the levels of physiological and security needs, using a hologeistic comparative method. Thirty cultures taken from the 60 cultural units in the Health Relations Area Files (HRAF) Probability Sample were found to have data available for examining hypotheses about thermoregulatory (physiological) and protective (security) behaviors practiced prior to sleep onset. The findings demonstrate there is initial worldwide empirical evidence to support Maslow's need hierarchy.

Competency-Based Education: A Quantitative Study of the U.S. Air Force Noncommissioned Officer Academy

ERIC Educational Resources Information Center

Houser, Bonnie L.

2017-01-01

There are relatively few empirical studies that examine whether using a competency-based education (CBE) approach results in increased student learning or achievement when compared to traditional education approaches. This study uses a quantitative research methodology, a nonexperimental comparative descriptive research design, and a two-group…

Comparing Empirically Historical Awareness in East and West Germany.

ERIC Educational Resources Information Center

Borries, Bodo von; Lehmann, Rainer H.

A study compared the historical awareness of 2,000 East and West German children in the sixth, ninth, and twelfth grades. Because of differing school systems and the general design of the study, researchers analyzed ninth grade data. The study was conducted during the disintegration and reunification of Germany. Students from the two regions…

Integrating technology readiness into the expectation-confirmation model: an empirical study of mobile services.

PubMed

Chen, Shih-Chih; Liu, Ming-Ling; Lin, Chieh-Peng

2013-08-01

The aim of this study was to integrate technology readiness into the expectation-confirmation model (ECM) for explaining individuals' continuance of mobile data service usage. After reviewing the ECM and technology readiness, an integrated model was demonstrated via empirical data. Compared with the original ECM, the findings of this study show that the integrated model may offer an ameliorated way to clarify what factors and how they influence the continuous intention toward mobile services. Finally, the major findings are summarized, and future research directions are suggested.

An empirical comparison of a dynamic software testability metric to static cyclomatic complexity

NASA Technical Reports Server (NTRS)

Voas, Jeffrey M.; Miller, Keith W.; Payne, Jeffrey E.

1993-01-01

This paper compares the dynamic testability prediction technique termed 'sensitivity analysis' to the static testability technique termed cyclomatic complexity. The application that we chose in this empirical study is a CASE generated version of a B-737 autoland system. For the B-737 system we analyzed, we isolated those functions that we predict are more prone to hide errors during system/reliability testing. We also analyzed the code with several other well-known static metrics. This paper compares and contrasts the results of sensitivity analysis to the results of the static metrics.

Weber, Durkheim, and the comparative method.

PubMed

Kapsis, R E

1977-10-01

This essay compares and contrasts the means by which Durkheim and Weber dealt with methodological issues peculiar to the comparative study of societies, what Smelser has called "the problem of sociocultural variability and complexity." More specifically, it examines how Weber and Durkheim chose appropriate comparative units for their empirical studies. The approaches that Weber and Durkheim brought to theproblem of cross-cultural comparison have critical implications for more current procedures used in the comparative study of contemporary and historical societies.

A Comparative Study of Socioeconomically Disadvantaged and Non-Socioeconomically Disadvantaged Fourth-Grade Students in Reading and Math in an Online Charter School and a Traditional School

ERIC Educational Resources Information Center

Mansheim, Richard Lynn

2017-01-01

Few empirical studies explore how socioeconomic status (SES) disadvantaged students perform academically in a 100% online school. This causal-comparative ex post facto quantitative study examined how SES-disadvantaged students at an online charter school performed academically when compared with both SES-disadvantaged and non-SES-disadvantaged…

Management strategy for patients with gastroesophageal reflux disease: a comparison between empirical treatment with esomeprazole and endoscopy-oriented treatment.

PubMed

Giannini, Edoardo G; Zentilin, Patrizia; Dulbecco, Pietro; Vigneri, Sergio; Scarlata, Pamela; Savarino, Vincenzo

2008-02-01

Whether patients with typical gastroesophageal reflux disease (GERD) symptoms and without alarm features should be treated empirically or undergo endoscopy first is a debated issue. In this study, our aim was to assess the efficacy, and to compare the direct costs and impact on health-related quality of life (HRQL), of two treatment strategies (empirical vs endoscopy-oriented treatment) in a large population of patients with GERD. In total, 612 patients were randomized to either empirical treatment with esomeprazole 40 mg once daily (od) (group 1, N = 309) or endoscopy and treatment according to endoscopic findings (group 2, N = 303, esomeprazole 40 mg od in patients with reflux esophagitis and esomeprazole 20 mg od in patients without esophagitis) for 4 wk, followed by esomeprazole 20 mg od maintenance treatment in both groups. Direct costs and HRQL were analyzed in both treatment arms. At the end of the acute treatment phase (week 4), 267 patients in group 1 (86.4%) and 265 patients in group 2 (87.5%) were considered responders to treatment (intention-to-treat analysis, P= 0.878). Empirical treatment proved to be cost-effective by saving 38.72 euros per treated patient. At the end of the maintenance phase (week 24), a similar proportion of patients responded to treatment in the two groups (71.8%vs 68.3%, P= 0.389). HRQL improved from baseline to week 24 in both groups (difference between study groups not significant). In patients with GERD, empirical treatment with esomeprazole proved to be cost-effective compared with endoscopy-oriented treatment, and did not negatively affect patient HRQL. These results should be taken into account in the management of GERD patients in clinical practice.

An Evaluation of Empirical Bayes' Estimation of Value- Added Teacher Performance Measures. Working Paper #31. Revised

ERIC Educational Resources Information Center

Guarino, Cassandra M.; Maxfield, Michelle; Reckase, Mark D.; Thompson, Paul; Wooldridge, Jeffrey M.

2014-01-01

Empirical Bayes' (EB) estimation is a widely used procedure to calculate teacher value-added. It is primarily viewed as a way to make imprecise estimates more reliable. In this paper we review the theory of EB estimation and use simulated data to study its ability to properly rank teachers. We compare the performance of EB estimators with that of…

Systematic review: third-line susceptibility-guided treatment for Helicobacter pylori infection

PubMed Central

Puig, Ignasi; López-Góngora, Sheila; Calvet, Xavier; Villoria, Albert; Baylina, Mireia; Sanchez-Delgado, Jordi; Suarez, David; García-Hernando, Victor; Gisbert, Javier P.

2015-01-01

Background: Susceptibility-guided therapies (SGTs) have been proposed as preferable to empirical rescue treatments after two treatment failures. The aim of this study was to perform a systematic review and meta-analysis evaluating the effectiveness and efficacy of SGT as third-line therapy. Methods: A systematic search was performed in multiple databases. Studies reporting cure rates of Helicobacter pylori with SGT in third-line therapy were selected. A qualitative analysis describing the current evidence and a pooled mean analysis summarizing the cure rates of SGT in third-line therapy was performed. Results: No randomized controlled trials or comparative studies were found. Four observational studies reported cure rates with SGT in third-line treatment, and three studies which mixed patients with second- and third-line treatment also reported cure rates with SGT. The majority of the studies included the patients when culture had been already obtained, and so the effectiveness of SGT and empirical therapy has never been compared. A pooled mean analysis including four observational studies (283 patients) showed intention-to-treat and per-protocol eradication rates with SGT of 72% (95% confidence interval 56–87%; I2: 92%) and 80% (95% confidence interval 71–90%; I2: 80%), respectively. Conclusions: SGT may be an acceptable option as rescue treatment. However, cure rates are, at best, moderate and this approach has never been compared with a well-devised empirical therapy. The evidence in favor of SGT as rescue therapy is currently insufficient to recommend its use. PMID:27366212

Strain, negative emotions, and juvenile delinquency: the United States versus taiwan.

PubMed

Lin, Wen-Hsu; Dembo, Richard; Sellers, Christine S; Cochran, John; Mieczkowski, Thomas

2014-04-01

General strain theory (GST) is an established criminological theory. Although the theory has been examined by many and enjoys empirical support, some limitations of previous studies need to be addressed. Many previous studies rely heavily on samples from Western countries, mostly the United States; thus, possible cultural influences are ignored. Although a few studies have moved forward by using subjects from Asia (e.g., China, Korea), these studies only provide empirical results regarding whether GST is applicable in other cultures. However, these studies do not directly compare Western and Eastern countries. The present study used two samples from the United States and Taiwan to directly compare and contrast central GST propositions. Although most of the GST propositions are found to be similar between the U.S. and Taiwanese juveniles, some differences were also discovered. Explanation of these similarities and differences from their cultural perspectives are offered in this study.

Maternal Identity of Hearing Mothers of Deaf Adolescents. Empirical Studies: An Interpersonal Approach

ERIC Educational Resources Information Center

Kobosko, Joanna; Zalewska, Marina

2011-01-01

The maternal identity of mothers of adolescents who are deaf has certain specific features compared with mothers of adolescents who have typical hearing. That is, maternal identity differs with respect to distinctiveness, self-representation, and representation of mother-child relationships. A study using a comparative paradigm was conducted. The…

Empirical Likelihood in Nonignorable Covariate-Missing Data Problems.

PubMed

Xie, Yanmei; Zhang, Biao

2017-04-20

Missing covariate data occurs often in regression analysis, which frequently arises in the health and social sciences as well as in survey sampling. We study methods for the analysis of a nonignorable covariate-missing data problem in an assumed conditional mean function when some covariates are completely observed but other covariates are missing for some subjects. We adopt the semiparametric perspective of Bartlett et al. (Improving upon the efficiency of complete case analysis when covariates are MNAR. Biostatistics 2014;15:719-30) on regression analyses with nonignorable missing covariates, in which they have introduced the use of two working models, the working probability model of missingness and the working conditional score model. In this paper, we study an empirical likelihood approach to nonignorable covariate-missing data problems with the objective of effectively utilizing the two working models in the analysis of covariate-missing data. We propose a unified approach to constructing a system of unbiased estimating equations, where there are more equations than unknown parameters of interest. One useful feature of these unbiased estimating equations is that they naturally incorporate the incomplete data into the data analysis, making it possible to seek efficient estimation of the parameter of interest even when the working regression function is not specified to be the optimal regression function. We apply the general methodology of empirical likelihood to optimally combine these unbiased estimating equations. We propose three maximum empirical likelihood estimators of the underlying regression parameters and compare their efficiencies with other existing competitors. We present a simulation study to compare the finite-sample performance of various methods with respect to bias, efficiency, and robustness to model misspecification. The proposed empirical likelihood method is also illustrated by an analysis of a data set from the US National Health and Nutrition Examination Survey (NHANES).

Efficient Robust Regression via Two-Stage Generalized Empirical Likelihood

PubMed Central

Bondell, Howard D.; Stefanski, Leonard A.

2013-01-01

Large- and finite-sample efficiency and resistance to outliers are the key goals of robust statistics. Although often not simultaneously attainable, we develop and study a linear regression estimator that comes close. Efficiency obtains from the estimator’s close connection to generalized empirical likelihood, and its favorable robustness properties are obtained by constraining the associated sum of (weighted) squared residuals. We prove maximum attainable finite-sample replacement breakdown point, and full asymptotic efficiency for normal errors. Simulation evidence shows that compared to existing robust regression estimators, the new estimator has relatively high efficiency for small sample sizes, and comparable outlier resistance. The estimator is further illustrated and compared to existing methods via application to a real data set with purported outliers. PMID:23976805

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

Cost-effectiveness of ceftolozane/tazobactam plus metronidazole compared with piperacillin/tazobactam as empiric therapy for the treatment of complicated intra-abdominal infections based on the in-vitro surveillance of bacterial isolates in the UK.

PubMed

Prabhu, Vimalanand; Foo, Jason; Ahir, Harblas; Sarpong, Eric; Merchant, Sanjay

2017-08-01

An increase in the prevalence of antimicrobial resistance among gram-negative pathogens has been noted recently. A challenge in empiric treatment of complicated intra-abdominal infection (cIAI) is identifying initial appropriate antibiotic therapy, which is associated with reduced length of stay and mortality compared with inappropriate therapy. The objective of this study was to assess the cost-effectiveness of ceftolozane/tazobactam + metronidazole compared with piperacillin/tazobactam (commonly used in this indication) in the treatment of patients with cIAI in UK hospitals. A decision-analytic Monte Carlo simulation model was used to compare costs (antibiotic and hospitalization costs) and quality-adjusted life years (QALYs) of patients infected with gram-negative cIAI and treated empirically with either ceftolozane/tazobactam + metronidazole or piperacillin/tazobactam. Bacterial isolates were randomly drawn from the Program to Assess Ceftolozane/Tazobactam Susceptibility (PACTS) database, a surveillance database of non-duplicate bacterial isolates collected from patients in the UK infected with gram-negative pathogens. Susceptibility to initial empiric therapy was based on the measured susceptibilities reported in the PACTS database. Ceftolozane/tazobactam + metronidazole was cost-effective when compared with piperacillin/tazobactam, with an incremental cost-effectiveness ratio (ICER) of £4,350/QALY and 0.36 hospitalization days/patient saved. Costs in the ceftolozane/tazobactam + metronidazole arm were £2,576/patient, compared with £2,168/patient in the piperacillin/tazobactam arm. The ceftolozane/tazobactam + metronidazole arm experienced a greater number of QALYs than the piperacillin/tazobactam arm (14.31/patient vs 14.21/patient, respectively). Ceftolozane/tazobactam + metronidazole remained cost-effective in one-way sensitivity and probabilistic sensitivity analyses. Economic models can help to identify the appropriate choice of empiric therapy for the treatment of cIAI. Results indicated that empiric use of ceftolozane/tazobactam + metronidazole is cost-effective vs piperacillin/tazobactam in UK patients with cIAI at risk of resistant infection. This will be valuable to commissioners and clinicians to aid decision-making on the targeting of resources for appropriate antibiotic therapy under the premise of antimicrobial stewardship.

Economic Comparison of an Empirical Versus Diagnostic-Driven Strategy for Treating Invasive Fungal Disease in Immunocompromised Patients.

PubMed

Barnes, Rosemary; Earnshaw, Stephanie; Herbrecht, Raoul; Morrissey, Orla; Slavin, Monica; Bow, Eric; McDade, Cheryl; Charbonneau, Claudie; Weinstein, David; Kantecki, Michal; Schlamm, Haran; Maertens, Johan

2015-06-01

Patients with persistent or recurrent neutropenic fevers at risk of invasive fungal disease (IFD) are treated empirically with antifungal therapy (AFT). Early treatment using a diagnostic-driven (DD) strategy may reduce clinical and economic burdens. We compared costs and outcomes of both strategies from a UK perspective. An empirical strategy with conventional amphotericin B deoxycholate (C-AmB), liposomal amphotericin B (L-AmB), or caspofungin was compared with a DD strategy (initiated based on positive ELISA results for galactomannan antigen) and/or positive results for Aspergillus species on polymerase chain reaction assay) using C-AmB, voriconazole, or L-AmB in a decision-analytic model. Rates of IFD incidence, overall mortality, and IFD-related mortality in adults expected to be neutropenic for ≥10 days were obtained. The empirical strategy was assumed to identify 30% of IFD and targeted AFT to improve survival by a hazard ratio of 0.589. AFT-specific adverse events were obtained from a summary of product characteristics. Resource use was obtained, and costs were estimated by using standard UK costing sources. All costs are presented in 2012 British pounds sterling. Total costs were 32% lower for the DD strategy (£1561.29) versus the empirical strategy (£2301.93) due to a reduced incidence of adverse events and decreased use of AFT. Administration of AFT was reduced by 41% (DD strategy, 74 of 1000; empirical strategy, 125 of 1000), with similar survival rates. This study suggests that a DD strategy is likely to be cost-saving versus empirical treatment for immunocompromised patients with persistent or recurrent neutropenic fevers. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Evidence-based ethics – What it should be and what it shouldn't

PubMed Central

Strech, Daniel

2008-01-01

Background The concept of evidence-based medicine has strongly influenced the appraisal and application of empirical information in health care decision-making. One principal characteristic of this concept is the distinction between "evidence" in the sense of high-quality empirical information on the one hand and rather low-quality empirical information on the other hand. In the last 5 to 10 years an increasing number of articles published in international journals have made use of the term "evidence-based ethics", making a systematic analysis and explication of the term and its applicability in ethics important. Discussion In this article four descriptive and two normative characteristics of the general concept "evidence-based" are presented and explained systematically. These characteristics are to then serve as a framework for assessing the methodological and practical challenges of evidence-based ethics as a developing methodology. The superiority of evidence in contrast to other empirical information has several normative implications such as the legitimization of decisions in medicine and ethics. This implicit normativity poses ethical concerns if there is no formal consent on which sort of empirical information deserves the label "evidence" and which does not. In empirical ethics, which relies primarily on interview research and other methods from the social sciences, we still lack gold standards for assessing the quality of study designs and appraising their findings. Conclusion The use of the term "evidence-based ethics" should be discouraged, unless there is enough consensus on how to differentiate between high- and low-quality information produced by empirical ethics. In the meantime, whenever empirical information plays a role, the process of ethical decision-making should make use of systematic reviews of empirical studies that involve a critical appraisal and comparative discussion of data. PMID:18937838

Fine structure of spectral properties for random correlation matrices: An application to financial markets

NASA Astrophysics Data System (ADS)

Livan, Giacomo; Alfarano, Simone; Scalas, Enrico

2011-07-01

We study some properties of eigenvalue spectra of financial correlation matrices. In particular, we investigate the nature of the large eigenvalue bulks which are observed empirically, and which have often been regarded as a consequence of the supposedly large amount of noise contained in financial data. We challenge this common knowledge by acting on the empirical correlation matrices of two data sets with a filtering procedure which highlights some of the cluster structure they contain, and we analyze the consequences of such filtering on eigenvalue spectra. We show that empirically observed eigenvalue bulks emerge as superpositions of smaller structures, which in turn emerge as a consequence of cross correlations between stocks. We interpret and corroborate these findings in terms of factor models, and we compare empirical spectra to those predicted by random matrix theory for such models.

Penicillin treatment for patients with Community-Acquired Pneumonia in Denmark: a retrospective cohort study.

PubMed

Egelund, Gertrud Baunbæk; Jensen, Andreas Vestergaard; Andersen, Stine Bang; Petersen, Pelle Trier; Lindhardt, Bjarne Ørskov; von Plessen, Christian; Rohde, Gernot; Ravn, Pernille

2017-04-20

Community-acquired pneumonia (CAP) is a severe infection, with high mortality. Antibiotic strategies for CAP differ across Europe. The objective of the study was to describe the epidemiology of CAP in Denmark and evaluate the prognosis of patients empirically treated with penicillin-G/V monotherapy. Retrospective cohort study including hospitalized patients with x-ray confirmed CAP. We calculated the population-based incidence, reviewed types of empiric antibiotics and duration of antibiotic treatment. We evaluated the association between mortality and treatment with empiric penicillin-G/V using logistic regression analysis. We included 1320 patients. The incidence of hospitalized CAP was 3.1/1000 inhabitants. Median age was 71 years (IQR; 58-81) and in-hospital mortality was 8%. Median duration of antibiotic treatment was 10 days (IQR; 8-12). In total 45% were treated with penicillin-G/V as empiric monotherapy and they did not have a higher mortality compared to patients treated with broader-spectrum antibiotics (OR 0.92, CI 95% 0.55-1.53). The duration of treatment exceeded recommendations in European guidelines. Empiric monotherapy with penicillin-G/V was commonly used and not associated with increased mortality in patients with mild to moderate pneumonia. Our results are in agreement with current conservative antibiotic strategy as outlined in the Danish guidelines.

Are Replication Studies Possible in Qualitative Second/Foreign Language Classroom Research? A Call for Comparative Re-Production Research

ERIC Educational Resources Information Center

Markee, Numa

2017-01-01

A widely accepted orthodoxy is that it is impossible to do replication studies within qualitative research paradigms. Ontologically and epistemologically speaking, such a view is largely correct. However, in this paper, I propose that what I call comparative re-production research--that is, the empirical study of qualitative phenomena that occur…

Determinants and Outcomes of Teachers' Professional Identity and Organizational Identification: A Comparative Analysis in Charter and Regular Public Schools

ERIC Educational Resources Information Center

Bogrek, Muhammed Fatih

2017-01-01

This empirical study compared the organizational identification and professional identity of teachers in charter and regular public schools. The purpose of study was three-fold; the first was to investigate whether charter school teachers differ from their regular public school peers in the study variables (i.e. self-efficacy, perceived…

Excavatability and the effect of weathering degree on the excavatability of rock masses: An example from Eastern Turkey

NASA Astrophysics Data System (ADS)

Gurocak, Zulfu; Yalcin, Erkut

2016-06-01

In this study, the effect of the weathering degree on the excavatability of rock masses was investigated. The ophiolitic rock mass along the route of Komurhan Tunnel was chosen as the case study. Both laboratory and field studies were carried out for this purpose. In the first stage, the ophiolitic rock mass along the tunnel route was classified into three subzones according to the weathering degree and the ophiolitic rock masses of the each subzones were classified using the empirical excavatability classifications proposed by the different researchers. Furthermore, in-situ excavatability classes of rock masses in each zone were determined and the results were compared. The in-situ excavatability class of fresh (Zone-I) and slightly weathered (Zone-II) rock masses was determined as Blasting and that of moderately weathered (Zone-III) rock mass was determined as Very Hard/Very Difficult. As the obtained results were compared, it was found that the weathering degree has a significant effect on the excavatability and that it is more appropriate to prefer empirical classifications in the empirical determination of excavatability classes of rock masses having the same lithology by taking the weathering degree into account.

Conspicuous by Their Absence: Studies Comparing and Combining Risperidone and Applied Behavior Analysis to Reduce Challenging Behavior in Children with Autism

ERIC Educational Resources Information Center

Weeden, Marc; Ehrhardt, Kristal; Poling, Alan

2009-01-01

Both risperidone, an atypical antipsychotic drug, and function-based behavior-analytic interventions are popular and empirically validated treatments for reducing challenging behavior in children with autism. The kind of research that supports their effectiveness differs, however, and no published study has directly compared their effects or…

Does Secondary School Size Make a Difference? A Systematic Review

ERIC Educational Resources Information Center

Newman, M.; Garrett, Z.; Elbourne, D.; Bradley, S.; Noden, P.; Taylor, J.; West, A.

2006-01-01

There is a vast body of literature on school size but comparatively few high quality empirical studies comparing outcomes in schools of different sizes. This systematic review synthesizes the results of the published research from 31 studies on the effects of secondary school size from OECD countries since 1990. Overall the directions and patterns…

Impact of Ethical and Affective Variables on Cheating: Comparison of Undergraduate Students with and without Jobs

ERIC Educational Resources Information Center

Hsiao, Chun-Hua

2015-01-01

Academic cheating is a serious problem among higher education organizations around the world. While most studies on academic cheating have focused on high school or college students, few have examined and compared students with and without jobs. Therefore, this study has empirically assessed the critical cheating issues by comparing undergraduate…

Students' Evaluations of Profit and Utility of Higher Education: A Comparative Case Study

ERIC Educational Resources Information Center

Davidovitch, Nitza; Lobovam Elena; Pryamikova, Elena; Semenova, Tatiana; Pechenkina, Tatiana; Yachmeneva, Maria

2013-01-01

This paper reviews the recent turn toward a capitalist approach to higher education with specific reference to the social, demographic, and legislative changes, including growing academic capitalism, which led to a transformation in Israel's higher education system. In an empirical comparative case study of students from Israel and Russia, this…

Empirical development of ground acceleration, velocity, and displacement for accidental explosions at J5 or the proposed large altitude rocket cell at Arnold Engineering Development Center

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

Davis, B.C.

This study is an assessment of the ground shock which may be generated in the event of an accidental explosion at J5 or the Proposed Large Altitude Rocket Cell (LARC) at the Arnold Engineering Development Center (AEDC). The assessment is accomplished by reviewing existing empirical relationships for predicting ground motion from ground shock. These relationships are compared with data for surface explosions at sites with similar geology and with yields similar to expected conditions at AEDC. Empirical relationships are developed from these data and a judgment made whether to use existing empirical relationships or the relationships developed in this study.more » An existing relationship (Lipner et al.) is used to predict velocity; the empirical relationships developed in the course of this study are used to predict acceleration and displacement. The ground motions are presented in table form and as contour plots. Included also is a discussion of damage criteria from blast and earthquake studies. This report recommends using velocity rather than acceleration as an indicator of structural blast damage. It is recommended that v = 2 ips (v = .167 fps) be used as the damage threshold value (no major damage for v less than or equal to 2 ips). 13 references, 25 figures, 6 tables.« less

De-escalation as part of a global strategy of empiric antibiotherapy management. A retrospective study in a medico-surgical intensive care unit

PubMed Central

2010-01-01

Introduction Most data on de-escalation of empirical antimicrobial therapy has focused on ventilator-associated pneumonia. In this retrospective monocentric study, we evaluated de-escalation as part of a global strategy of empiric antibiotherapy management irrespective of the location and the severity of the infection. The goal of this trial was to assess the application of a de-escalation strategy and the impact in terms of re-escalation, recurrent infection and to identify variables associated with de-escalation. Methods All consecutive patients treated with empiric antibiotic therapy and hospitalized in the intensive care unit for at least 72 hours within a period of 16 months were included. We compared the characteristics and outcome of patients who have experienced de-escalation therapy with those who have not. Results A total of 116 patients were studied corresponding to 133 infections. Antibiotic therapy was de-escalated in 60 cases (45%). De-escalation, primarily accomplished by a reduction in the number of antibiotics used, was observed in 52% of severe sepsis or septic shock patients. Adequate empiric antibiotic and use of aminoglycoside were independently linked with de-escalation. De-escalation therapy was associated with a significant reduction of recurrent infection (19% vs 5% P = 0.01). Mortality was not changed by de-escalation. Conclusions As part of a global management of empiric antibiotherapy in an intensive care unit, de-escalation might be safe and feasible in a large proportion of patients. PMID:21167047

De-escalation as part of a global strategy of empiric antibiotherapy management. A retrospective study in a medico-surgical intensive care unit.

PubMed

Morel, Jérôme; Casoetto, Julie; Jospé, Richard; Aubert, Gérald; Terrana, Raphael; Dumont, Alain; Molliex, Serge; Auboyer, Christian

2010-01-01

Most data on de-escalation of empirical antimicrobial therapy has focused on ventilator-associated pneumonia. In this retrospective monocentric study, we evaluated de-escalation as part of a global strategy of empiric antibiotherapy management irrespective of the location and the severity of the infection. The goal of this trial was to assess the application of a de-escalation strategy and the impact in terms of re-escalation, recurrent infection and to identify variables associated with de-escalation. All consecutive patients treated with empiric antibiotic therapy and hospitalized in the intensive care unit for at least 72 hours within a period of 16 months were included. We compared the characteristics and outcome of patients who have experienced de-escalation therapy with those who have not. A total of 116 patients were studied corresponding to 133 infections. Antibiotic therapy was de-escalated in 60 cases (45%). De-escalation, primarily accomplished by a reduction in the number of antibiotics used, was observed in 52% of severe sepsis or septic shock patients. Adequate empiric antibiotic and use of aminoglycoside were independently linked with de-escalation. De-escalation therapy was associated with a significant reduction of recurrent infection (19% vs 5% P = 0.01). Mortality was not changed by de-escalation. As part of a global management of empiric antibiotherapy in an intensive care unit, de-escalation might be safe and feasible in a large proportion of patients.

Empiric therapy directed against MRSA in patients admitted to the intensive care unit does not improve outcomes in community-acquired pneumonia.

PubMed

Griffin, A T; Peyrani, P; Wiemken, T L; Ramirez, J A; Arnold, F W

2013-04-01

The Infectious Diseases Society of America has recommended empiric therapy active against methicillin-resistant Staphylococcus aureus (MRSA) for all community-acquired pneumonia (CAP) patients admitted to the intensive care unit (ICU). However, there is sparse data to support this recommendation. The objective of our study was to ascertain if such a practice improves outcomes. This study was a secondary, retrospective analysis of the Community-Acquired Pneumonia Organization (CAPO) international database on CAP. Outcomes in patients admitted to the ICU were compared according to empiric initiation of anti-MRSA therapy (vancomycin or linezolid) with standard ICU CAP therapy (MRSA therapy group) or standard therapy alone for ICU CAP (standard therapy group). A total of 621 patients were identified with ICU pneumonia, of whom 57 patients had been initiated empirically on vancomycin or linezolid (MRSA therapy group). Patients of the MRSA therapy group had more comorbidities and were more severely ill than those of the standard therapy group. However, there were no statistical differences between the MRSA therapy group and standard therapy group for the primary outcomes of in-hospital and 28-day mortality, length of stay and time to clinical stability. These findings suggest that empiric MRSA therapy in all ICU CAP patients may not improve outcomes and argue for clinician review of local epidemiologic trends on MRSA prevalence to ascertain the need for empiric MRSA coverage.

PolyWaTT: A polynomial water travel time estimator based on Derivative Dynamic Time Warping and Perceptually Important Points

NASA Astrophysics Data System (ADS)

Claure, Yuri Navarro; Matsubara, Edson Takashi; Padovani, Carlos; Prati, Ronaldo Cristiano

2018-03-01

Traditional methods for estimating timing parameters in hydrological science require a rigorous study of the relations of flow resistance, slope, flow regime, watershed size, water velocity, and other local variables. These studies are mostly based on empirical observations, where the timing parameter is estimated using empirically derived formulas. The application of these studies to other locations is not always direct. The locations in which equations are used should have comparable characteristics to the locations from which such equations have been derived. To overcome this barrier, in this work, we developed a data-driven approach to estimate timing parameters such as travel time. Our proposal estimates timing parameters using historical data of the location without the need of adapting or using empirical formulas from other locations. The proposal only uses one variable measured at two different locations on the same river (for instance, two river-level measurements, one upstream and the other downstream on the same river). The recorded data from each location generates two time series. Our method aligns these two time series using derivative dynamic time warping (DDTW) and perceptually important points (PIP). Using data from timing parameters, a polynomial function generalizes the data by inducing a polynomial water travel time estimator, called PolyWaTT. To evaluate the potential of our proposal, we applied PolyWaTT to three different watersheds: a floodplain ecosystem located in the part of Brazil known as Pantanal, the world's largest tropical wetland area; and the Missouri River and the Pearl River, in United States of America. We compared our proposal with empirical formulas and a data-driven state-of-the-art method. The experimental results demonstrate that PolyWaTT showed a lower mean absolute error than all other methods tested in this study, and for longer distances the mean absolute error achieved by PolyWaTT is three times smaller than empirical formulas.

An Australian Study Comparing the Use of Multiple-Choice Questionnaires with Assignments as Interim, Summative Law School Assessment

ERIC Educational Resources Information Center

Huang, Vicki

2017-01-01

To the author's knowledge, this is the first Australian study to empirically compare the use of a multiple-choice questionnaire (MCQ) with the use of a written assignment for interim, summative law school assessment. This study also surveyed the same student sample as to what types of assessments are preferred and why. In total, 182 undergraduate…

Gender and Regional Differences in Creativity: A Comparative Study on Playfulness and Humor in Postgraduate Students between Mainland China and Taiwan

ERIC Educational Resources Information Center

Luo, Lingling; Zhou, Chunfang; Zhang, Song

2016-01-01

This article aims to study both similarities and differences in female students' creativity between Mainland China and Taiwan. As two main aspects influencing creativity, playfulness and humor are especially focused on in this comparative study. Empirical data were collected from 831 students in Mainland China and 703 students in Taiwan. Based on…

The effects of clinical supervision on supervisees and patients in cognitive behavioral therapy: a systematic review.

PubMed

Alfonsson, Sven; Parling, Thomas; Spännargård, Åsa; Andersson, Gerhard; Lundgren, Tobias

2018-05-01

Clinical supervision is a central part of psychotherapist training but the empirical support for specific supervision theories or features is unclear. The aims of this study were to systematically review the empirical research literature regarding the effects of clinical supervision on therapists' competences and clinical outcomes within Cognitive Behavior Therapy (CBT). A comprehensive database search resulted in 4103 identified publications. Of these, 133 were scrutinized and in the end 5 studies were included in the review for data synthesis. The five studies were heterogeneous in scope and quality and only one provided firm empirical support for the positive effects of clinical supervision on therapists' competence. The remaining four studies suffered from methodological weaknesses, but provided some preliminary support that clinical supervision may be beneficiary for novice therapists. No study could show benefits from supervision for patients. The research literature suggests that clinical supervision may have some potential effects on novice therapists' competence compared to no supervision but the effects on clinical outcomes are still unclear. While bug-in-the-eye live supervision may be more effective than standard delayed supervision, the effects of specific supervision models or features are also unclear. There is a continued need for high-quality empirical studies on the effects of clinical supervision in psychotherapy.

Towards an empirical ethics in care: relations with technologies in health care.

PubMed

Pols, Jeannette

2015-02-01

This paper describes the approach of empirical ethics, a form of ethics that integrates non-positivist ethnographic empirical research and philosophy. Empirical ethics as it is discussed here builds on the 'empirical turn' in epistemology. It radicalizes the relational approach that care ethics introduced to think about care between people by drawing in relations between people and technologies as things people relate to. Empirical ethics studies care practices by analysing their intra-normativity, or the ways of living together the actors within these practices strive for or bring about as good practices. Different from care ethics, what care is and if it is good is not defined beforehand. A care practice may be contested by comparing it to alternative practices with different notions of good care. By contrasting practices as different ways of living together that are normatively oriented, suggestions for the best possible care may be argued for. Whether these suggestions will actually be put to practice is, however, again a relational question; new actors need to re-localize suggestions, to make them work in new practices and fit them in with local intra-normativities with their particular routines, material infrastructures, know-how and strivings.

An empirical approach to estimate near-infra-red photon propagation and optically induced drug release in brain tissues

NASA Astrophysics Data System (ADS)

Prabhu Verleker, Akshay; Fang, Qianqian; Choi, Mi-Ran; Clare, Susan; Stantz, Keith M.

2015-03-01

The purpose of this study is to develop an alternate empirical approach to estimate near-infra-red (NIR) photon propagation and quantify optically induced drug release in brain metastasis, without relying on computationally expensive Monte Carlo techniques (gold standard). Targeted drug delivery with optically induced drug release is a noninvasive means to treat cancers and metastasis. This study is part of a larger project to treat brain metastasis by delivering lapatinib-drug-nanocomplexes and activating NIR-induced drug release. The empirical model was developed using a weighted approach to estimate photon scattering in tissues and calibrated using a GPU based 3D Monte Carlo. The empirical model was developed and tested against Monte Carlo in optical brain phantoms for pencil beams (width 1mm) and broad beams (width 10mm). The empirical algorithm was tested against the Monte Carlo for different albedos along with diffusion equation and in simulated brain phantoms resembling white-matter (μs'=8.25mm-1, μa=0.005mm-1) and gray-matter (μs'=2.45mm-1, μa=0.035mm-1) at wavelength 800nm. The goodness of fit between the two models was determined using coefficient of determination (R-squared analysis). Preliminary results show the Empirical algorithm matches Monte Carlo simulated fluence over a wide range of albedo (0.7 to 0.99), while the diffusion equation fails for lower albedo. The photon fluence generated by empirical code matched the Monte Carlo in homogeneous phantoms (R2=0.99). While GPU based Monte Carlo achieved 300X acceleration compared to earlier CPU based models, the empirical code is 700X faster than the Monte Carlo for a typical super-Gaussian laser beam.

Evolutionary Developmental Psychology: Contributions from Comparative Research with Nonhuman Primates

ERIC Educational Resources Information Center

Maestripieri, Dario; Roney, James R.

2006-01-01

Evolutionary developmental psychology is a discipline that has the potential to integrate conceptual approaches to the study of behavioral development derived from psychology and biology as well as empirical data from humans and animals. Comparative research with animals, and especially with nonhuman primates, can provide evidence of adaptation in…

Comparing online and offline self-disclosure: a systematic review.

PubMed

Nguyen, Melanie; Bin, Yu Sun; Campbell, Andrew

2012-02-01

Disclosure of personal information is believed to be more frequent in online compared to offline communication. However, this assumption is both theoretically and empirically contested. This systematic review examined existing research comparing online and offline self-disclosure to ascertain the evidence for current theories of online communication. Studies that compared online and offline disclosures in dyadic interactions were included for review. Contrary to expectations, disclosure was not consistently found to be greater in online contexts. Factors such as the relationship between the communicators, the specific mode of communication, and the context of the interaction appear to moderate the degree of disclosure. In relation to the theories of online communication, there is support for each theory. It is argued that the overlapping predictions of each theory and the current state of empirical research highlights a need for an overarching theory of communication that can account for disclosure in both online and offline interactions.

A test-based strategy is more cost effective than empiric dose escalation for patients with Crohn's disease who lose responsiveness to infliximab.

PubMed

Velayos, Fernando S; Kahn, James G; Sandborn, William J; Feagan, Brian G

2013-06-01

Patients with Crohn's disease who become unresponsive to therapy with tumor necrosis factor antagonists are managed initially with either empiric dose escalation or testing-based strategies. The comparative cost effectiveness of these 2 strategies is unknown. We investigated whether a testing-based strategy is more cost effective than an empiric dose-escalation strategy. A decision analytic model that simulated 2 cohorts of patients with Crohn's disease compared outcomes for the 2 strategies over a 1-year time period. The incremental cost-effectiveness ratio of the empiric strategy was expressed as cost per quality-adjusted life-year (QALY) gained, compared with the testing-based strategy. We performed 1-way, probabilistic, and prespecified secondary analyses. The testing strategy yielded similar QALYs compared with the empiric strategy (0.801 vs 0.800, respectively) but was less expensive ($31,870 vs $37,266, respectively). In sensitivity analyses, the incremental cost-effectiveness ratio of the empiric strategy ranged from $500,000 to more than $5 million per QALY gained. Similar rates of remission (63% vs 66%) and response (28% vs 26%) were achieved through differential use of available interventions. The testing-based strategy resulted in a higher percentage of surgeries (48% vs 34%) and lower percentage use of high-dose biological therapy (41% vs 54%). A testing-based strategy is a cost-effective alternative to the current strategy of empiric dose escalation for managing patients with Crohn's disease who have lost responsiveness to infliximab. The basis for this difference is lower cost at similar outcomes. Copyright © 2013 AGA Institute. Published by Elsevier Inc. All rights reserved.

Change in Indices of Distress among Latino and Anglo Female Caregivers of Elderly Relatives with Dementia: Site-Specific Results from the REACH National Collaborative Study

ERIC Educational Resources Information Center

Gallagher-Thompson, Dolores; Coon, David W.; Solano, Nancy; Ambler, Christian; Rabinowitz, Yaron; Thompson, Larry W.

2003-01-01

Purpose: Few empirical studies have compared the efficacy between psychoeducational (skill-building) approaches for reducing caregivers' psychological distress and interventions modeled after typical community-based support groups. We compare the impact of two distinct interventions on Anglo and Latino caregivers of elderly relatives with…

Empirically Supported Treatment’s Impact on Organizational Culture and Climate

PubMed Central

Patterson-Silver Wolf, David A.; Dulmus, Catherine N.; Maguin, Eugene

2012-01-01

Objectives With the continued push to implement empirically supported treatments (ESTs) into community-based organizations, it is important to investigate whether working condition disruptions occur during this process. While there are many studies investigating best practices and how to adopt them, the literature lacks studies investigating the working conditions in programs that currently use ESTs. Method This study compared the culture and climate scores of a large organization’s programs that use ESTs and those programs indicating no EST usage. Results Of the total 55 different programs (1,273 frontline workers), 27 programs used ESTs. Results indicate that the programs offering an EST had significantly more rigid and resistant cultures, compared to those without any ESTs. In regard to climate, programs offering an EST were significantly less engaged, less functional, and more stressed. Conclusion Outcomes indicate a significant disruption in organizational culture and climate for programs offering ESTs. PMID:23243379

Empirically Supported Treatment's Impact on Organizational Culture and Climate.

PubMed

Patterson-Silver Wolf, David A; Dulmus, Catherine N; Maguin, Eugene

2012-11-01

OBJECTIVES: With the continued push to implement empirically supported treatments (ESTs) into community-based organizations, it is important to investigate whether working condition disruptions occur during this process. While there are many studies investigating best practices and how to adopt them, the literature lacks studies investigating the working conditions in programs that currently use ESTs. METHOD: This study compared the culture and climate scores of a large organization's programs that use ESTs and those programs indicating no EST usage. RESULTS: Of the total 55 different programs (1,273 frontline workers), 27 programs used ESTs. Results indicate that the programs offering an EST had significantly more rigid and resistant cultures, compared to those without any ESTs. In regard to climate, programs offering an EST were significantly less engaged, less functional, and more stressed. CONCLUSION: Outcomes indicate a significant disruption in organizational culture and climate for programs offering ESTs.

The Ocean Colour Climate Change Initiative: III. A Round-Robin Comparison on In-Water Bio-Optical Algorithms

NASA Technical Reports Server (NTRS)

Brewin, Robert J.W.; Sathyendranath, Shubha; Muller, Dagmar; Brockmann, Carsten; Deschamps, Pierre-Yves; Devred, Emmanuel; Doerffer, Roland; Fomferra, Norman; Franz, Bryan; Grant, Mike;

A study of a diffusive model of asset returns and an empirical analysis of financial markets

NASA Astrophysics Data System (ADS)

Alejandro Quinones, Angel Luis

A diffusive model for market dynamics is studied and the predictions of the model are compared to real financial markets. The model has a non-constant diffusion coefficient which depends both on the asset value and the time. A general solution for the distribution of returns is obtained and shown to match the results of computer simulations for two simple cases, piecewise linear and quadratic diffusion. The effects of discreteness in the market dynamics on the model are also studied. For the quadratic diffusion case, a type of phase transition leading to fat tails is observed as the discrete distribution approaches the continuum limit. It is also found that the model captures some of the empirical stylized facts observed in real markets, including fat-tails and scaling behavior in the distribution of returns. An analysis of empirical data for the EUR/USD currency exchange rate and the S&P 500 index is performed. Both markets show time scaling behavior consistent with a value of 1/2 for the Hurst exponent. Finally, the results show that the distribution of returns for the two markets is well fitted by the model, and the corresponding empirical diffusion coefficients are determined.

In Defence of International Comparative Studies. on the Analytical and Explanatory Power of the Nation State in International Comparative Higher Education Research

ERIC Educational Resources Information Center

Kosmützky, Anna

2015-01-01

Higher education is undergoing a process of globalization and new realities of a globalized higher education world are emerging. Globalization also has a profound impact on higher education research. Global and transnational topics are theoretically and empirically elaborated and seem on the rise, whereas the international comparative outlook…

Recent ecological responses to climate change support predictions of high extinction risk

PubMed Central

Maclean, Ilya M. D.; Wilson, Robert J.

2011-01-01

Predicted effects of climate change include high extinction risk for many species, but confidence in these predictions is undermined by a perceived lack of empirical support. Many studies have now documented ecological responses to recent climate change, providing the opportunity to test whether the magnitude and nature of recent responses match predictions. Here, we perform a global and multitaxon metaanalysis to show that empirical evidence for the realized effects of climate change supports predictions of future extinction risk. We use International Union for Conservation of Nature (IUCN) Red List criteria as a common scale to estimate extinction risks from a wide range of climate impacts, ecological responses, and methods of analysis, and we compare predictions with observations. Mean extinction probability across studies making predictions of the future effects of climate change was 7% by 2100 compared with 15% based on observed responses. After taking account of possible bias in the type of climate change impact analyzed and the parts of the world and taxa studied, there was less discrepancy between the two approaches: predictions suggested a mean extinction probability of 10% across taxa and regions, whereas empirical evidence gave a mean probability of 14%. As well as mean overall extinction probability, observations also supported predictions in terms of variability in extinction risk and the relative risk associated with broad taxonomic groups and geographic regions. These results suggest that predictions are robust to methodological assumptions and provide strong empirical support for the assertion that anthropogenic climate change is now a major threat to global biodiversity. PMID:21746924

Recent ecological responses to climate change support predictions of high extinction risk.

PubMed

Maclean, Ilya M D; Wilson, Robert J

2011-07-26

Predicted effects of climate change include high extinction risk for many species, but confidence in these predictions is undermined by a perceived lack of empirical support. Many studies have now documented ecological responses to recent climate change, providing the opportunity to test whether the magnitude and nature of recent responses match predictions. Here, we perform a global and multitaxon metaanalysis to show that empirical evidence for the realized effects of climate change supports predictions of future extinction risk. We use International Union for Conservation of Nature (IUCN) Red List criteria as a common scale to estimate extinction risks from a wide range of climate impacts, ecological responses, and methods of analysis, and we compare predictions with observations. Mean extinction probability across studies making predictions of the future effects of climate change was 7% by 2100 compared with 15% based on observed responses. After taking account of possible bias in the type of climate change impact analyzed and the parts of the world and taxa studied, there was less discrepancy between the two approaches: predictions suggested a mean extinction probability of 10% across taxa and regions, whereas empirical evidence gave a mean probability of 14%. As well as mean overall extinction probability, observations also supported predictions in terms of variability in extinction risk and the relative risk associated with broad taxonomic groups and geographic regions. These results suggest that predictions are robust to methodological assumptions and provide strong empirical support for the assertion that anthropogenic climate change is now a major threat to global biodiversity.

Ab initio and empirical energy landscapes of (MgF2)n clusters (n = 3, 4).

PubMed

Neelamraju, S; Schön, J C; Doll, K; Jansen, M

2012-01-21

We explore the energy landscape of (MgF(2))(3) on both the empirical and ab initio level using the threshold algorithm. In order to determine the energy landscape and the dynamics of the trimer we investigate not only the stable isomers but also the barriers separating these isomers. Furthermore, we study the probability flows in order to estimate the stability of all the isomers found. We find that there is reasonable qualitative agreement between the ab initio and empirical potential, and important features such as sub-basins and energetic barriers follow similar trends. However, we observe that the energies are systematically different for the less compact clusters, when comparing empirical and ab initio energies. Since the underlying motivation of this work is to identify the possible clusters present in the gas phase during a low-temperature atom beam deposition synthesis of MgF(2), we employ the same procedure to additionally investigate the energy landscape of the tetramer. For this case, however, we use only the empirical potential.

Clinical characteristics of ceftriaxone plus metronidazole in complicated intra-abdominal infection

PubMed Central

2015-01-01

Purpose Empirical antibiotics in complicated intra-abdominal infection (c-IAI), such as secondary peritonitis are a first step of treatment. Empirical antibiotic regimen is very diverse. Ceftriaxone plus metronidazole regimen (CMR) is one of the empirical antibiotic regimens used in treatment of c-IAI. However, although CMR is a widely used empirical antibiotic regimen, study regarding success, failure or efficacy of CMR has been poorly understood. This retrospective study is conducted to compare the clinical efficacy of this regimen in c-IAI according to clinical characteristics. Methods The subjects were patients in this hospital who were diagnosed as secondary peritonitis between 2009 and 2013. Retrospective analysis was performed based on the records made after surgery regarding clinical characteristics including albumin level, blood pressure, pulse rate, respiration rate, smoking, age, sex, body mass index, hemoglobin, coexisting disease, leukocytosis, and APACHE (acute physiology and chronic health evaluation) II score. Results A total of 114 patients were enrolled. In univariated analysis, the success and failure of CMR showed significant association with preoperative low albumin, old age, and preoperative tachycardia. In multivariated analysis, low albumin and preoperative tachycardia were significant. Conclusion It is thought that an additional antibiotic treatment plan is necessary in patients with low albumin and tachycardia when the empirical antibiotic regimen is CMR in c-IAI. Conduct of research through well-designed prospective randomized clinical study is also necessary in order to evaluate the appropriateness of CMR and decide on a proper empirical antibiotic regimen between many regimens in c-IAI based on our country. PMID:26131444

Test Score Equating Using Discrete Anchor Items versus Passage-Based Anchor Items: A Case Study Using "SAT"® Data. Research Report. ETS RR-14-14

ERIC Educational Resources Information Center

Liu, Jinghua; Zu, Jiyun; Curley, Edward; Carey, Jill

2014-01-01

The purpose of this study is to investigate the impact of discrete anchor items versus passage-based anchor items on observed score equating using empirical data.This study compares an "SAT"® critical reading anchor that contains more discrete items proportionally, compared to the total tests to be equated, to another anchor that…

Empirical investigation of a field theory formula and Black's formula for the price of an interest-rate caplet

NASA Astrophysics Data System (ADS)

Baaquie, Belal E.; Liang, Cui

2007-01-01

The industry standard for pricing an interest-rate caplet is Black's formula. Another distinct price of the same caplet can be derived using a quantum field theory model of the forward interest rates. An empirical study is carried out to compare the two caplet pricing formulae. Historical volatility and correlation of forward interest rates are used to generate the field theory caplet price; another approach is to fit a parametric formula for the effective volatility using market caplet price. The study shows that the field theory model generates the price of a caplet and cap fairly accurately. Black's formula for a caplet is compared with field theory pricing formula. It is seen that the field theory formula for caplet price has many advantages over Black's formula.

A study of transonic aerodynamic analysis methods for use with a hypersonic aircraft synthesis code

NASA Technical Reports Server (NTRS)

Sandlin, Doral R.; Davis, Paul Christopher

1992-01-01

A means of performing routine transonic lift, drag, and moment analyses on hypersonic all-body and wing-body configurations were studied. The analysis method is to be used in conjunction with the Hypersonic Vehicle Optimization Code (HAVOC). A review of existing techniques is presented, after which three methods, chosen to represent a spectrum of capabilities, are tested and the results are compared with experimental data. The three methods consist of a wave drag code, a full potential code, and a Navier-Stokes code. The wave drag code, representing the empirical approach, has very fast CPU times, but very limited and sporadic results. The full potential code provides results which compare favorably to the wind tunnel data, but with a dramatic increase in computational time. Even more extreme is the Navier-Stokes code, which provides the most favorable and complete results, but with a very large turnaround time. The full potential code, TRANAIR, is used for additional analyses, because of the superior results it can provide over empirical and semi-empirical methods, and because of its automated grid generation. TRANAIR analyses include an all body hypersonic cruise configuration and an oblique flying wing supersonic transport.

Time to Guideline-Based Empiric Antibiotic Therapy in the Treatment of Pneumonia in a Community Hospital: A Retrospective Review.

PubMed

Erwin, Beth L; Kyle, Jeffrey A; Allen, Leland N

2016-08-01

The 2005 American Thoracic Society/Infectious Diseases Society of America (ATS/IDSA) guidelines for hospital-acquired pneumonia (HAP), ventilator-associated pneumonia (VAP), and health care-associated pneumonia (HCAP) stress the importance of initiating prompt appropriate empiric antibiotic therapy. This study's purpose was to determine the percentage of patients with HAP, VAP, and HCAP who received guideline-based empiric antibiotic therapy and to determine the average time to receipt of an appropriate empiric regimen. A retrospective chart review of adults with HAP, VAP, or HCAP was conducted at a community hospital in suburban Birmingham, Alabama. The hospital's electronic medical record system utilized International Classification of Diseases, Ninth Revision (ICD-9) codes to identify patients diagnosed with pneumonia. The percentage of patients who received guideline-based empiric antibiotic therapy was calculated. The mean time from suspected diagnosis of pneumonia to initial administration of the final antibiotic within the empiric regimen was calculated for patients who received guideline-based therapy. Ninety-three patients met the inclusion criteria. The overall guideline adherence rate for empiric antibiotic therapy was 31.2%. The mean time to guideline-based therapy in hours:minutes was 7:47 for HAP and 28:16 for HCAP. For HAP and HCAP combined, the mean time to appropriate therapy was 21:55. Guideline adherence rates were lower and time to appropriate empiric therapy was greater for patients with HCAP compared to patients with HAP. © The Author(s) 2015.

Cost-effectiveness evaluation of voriconazole versus liposomal amphotericin B as empirical therapy for febrile neutropenia in Australia.

PubMed

Al-Badriyeh, Daoud; Liew, Danny; Stewart, Kay; Kong, David C M

2009-01-01

A major randomized clinical trial, evaluating voriconazole versus liposomal amphotericin B (LAMB) as empirical therapy in febrile neutropenia, recommended voriconazole as a suitable alternative to LAMB. The current study sought to investigate the health economic impact of using voriconazole and LAMB for febrile neutropenia in Australia. A decision analytic model was constructed to capture downstream consequences of empirical antifungal therapy with each agent. The main outcomes were: success, breakthrough fungal infection, persistent baseline fungal infection, persistent fever, premature discontinuation and death. Underlying transition probabilities and treatment patterns were derived directly from trial data. Resource use was estimated using an expert panel. Cost inputs were obtained from the latest Australian representative published sources. The perspective adopted was that of the Australian hospital. Uncertainty and sensitivity analyses were undertaken via the Monte Carlo simulation. Compared with voriconazole, LAMB was associated with a net cost saving of AU$1422 (2.9%) per patient. A similar trend was observed with the cost per death prevented and successful treatment. LAMB dominated voriconazole as it resulted in higher efficacy and lower costs when compared with voriconazole. The results were most sensitive to the duration of therapy and the alternative therapy used post discontinuations. In uncertainty analysis, LAMB had 99.8% chance of costing less than voriconazole. In this study, which used the current standard five component endpoint to assess the impact of empirical antifungal therapy, LAMB was associated with cost savings relative to voriconazole.

Development of Specialization Scales for the MSPI: A Comparison of Empirical and Inductive Strategies

ERIC Educational Resources Information Center

Porfeli, Erik J.; Richard, George V.; Savickas, Mark L.

2010-01-01

An empirical measurement model for interest inventory construction uses internal criteria whereas an inductive measurement model uses external criteria. The empirical and inductive measurement models are compared and contrasted and then two models are assessed through tests of the effectiveness and economy of scales for the Medical Specialty…

Empirical tuberculosis therapy versus isoniazid in adult outpatients with advanced HIV initiating antiretroviral therapy (REMEMBER): a multicountry open-label randomised controlled trial.

PubMed

Hosseinipour, Mina C; Bisson, Gregory P; Miyahara, Sachiko; Sun, Xin; Moses, Agnes; Riviere, Cynthia; Kirui, Fredrick K; Badal-Faesen, Sharlaa; Lagat, David; Nyirenda, Mulinda; Naidoo, Kogieleum; Hakim, James; Mugyenyi, Peter; Henostroza, German; Leger, Paul D; Lama, Javier R; Mohapi, Lerato; Alave, Jorge; Mave, Vidya; Veloso, Valdilea G; Pillay, Sandy; Kumarasamy, Nagalingeswaran; Bao, Jing; Hogg, Evelyn; Jones, Lynne; Zolopa, Andrew; Kumwenda, Johnstone; Gupta, Amita

2016-03-19

Mortality within the first 6 months after initiating antiretroviral therapy is common in resource-limited settings and is often due to tuberculosis in patients with advanced HIV disease. Isoniazid preventive therapy is recommended in HIV-positive adults, but subclinical tuberculosis can be difficult to diagnose. We aimed to assess whether empirical tuberculosis treatment would reduce early mortality compared with isoniazid preventive therapy in high-burden settings. We did a multicountry open-label randomised clinical trial comparing empirical tuberculosis therapy with isoniazid preventive therapy in HIV-positive outpatients initiating antiretroviral therapy with CD4 cell counts of less than 50 cells per μL. Participants were recruited from 18 outpatient research clinics in ten countries (Malawi, South Africa, Haiti, Kenya, Zambia, India, Brazil, Zimbabwe, Peru, and Uganda). Individuals were screened for tuberculosis using a symptom screen, locally available diagnostics, and the GeneXpert MTB/RIF assay when available before inclusion. Study candidates with confirmed or suspected tuberculosis were excluded. Inclusion criteria were liver function tests 2·5 times the upper limit of normal or less, a creatinine clearance of at least 30 mL/min, and a Karnofsky score of at least 30. Participants were randomly assigned (1:1) to either the empirical group (antiretroviral therapy and empirical tuberculosis therapy) or the isoniazid preventive therapy group (antiretroviral therapy and isoniazid preventive therapy). The primary endpoint was survival (death or unknown status) at 24 weeks after randomisation assessed in the intention-to-treat population. Kaplan-Meier estimates of the primary endpoint across groups were compared by the z-test. All participants were included in the safety analysis of antiretroviral therapy and tuberculosis treatment. This trial is registered with ClinicalTrials.gov, number NCT01380080. Between Oct 31, 2011, and June 9, 2014, we enrolled 850 participants. Of these, we randomly assigned 424 to receive empirical tuberculosis therapy and 426 to the isoniazid preventive therapy group. The median CD4 cell count at baseline was 18 cells per μL (IQR 9-32). At week 24, 22 (5%) participants from each group died or were of unknown status (95% CI 3·5-7·8) for empirical group and for isoniazid preventive therapy (95% CI 3·4-7·8); absolute risk difference of -0·06% (95% CI -3·05 to 2·94). Grade 3 or 4 signs or symptoms occurred in 50 (12%) participants in the empirical group and 46 (11%) participants in the isoniazid preventive therapy group. Grade 3 or 4 laboratory abnormalities occurred in 99 (23%) participants in the empirical group and 97 (23%) participants in the isoniazid preventive therapy group. Empirical tuberculosis therapy did not reduce mortality at 24 weeks compared with isoniazid preventive therapy in outpatient adults with advanced HIV disease initiating antiretroviral therapy. The low mortality rate of the trial supports implementation of systematic tuberculosis screening and isoniazid preventive therapy in outpatients with advanced HIV disease. National Institutes of Allergy and Infectious Diseases through the AIDS Clinical Trials Group. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparison of Performance Due to Guided Hyperlearning, Unguided Hyperlearning, and Conventional Learning in Mathematics: An Empirical Study

ERIC Educational Resources Information Center

Fathurrohman, Maman; Porter, Anne; Worthy, Annette L.

2014-01-01

In this paper, the use of guided hyperlearning, unguided hyperlearning, and conventional learning methods in mathematics are compared. The design of the research involved a quasi-experiment with a modified single-factor multiple treatment design comparing the three learning methods, guided hyperlearning, unguided hyperlearning, and conventional…

Comparing Achievement between K-8 and Middle Schools: A Large-Scale Empirical Study

ERIC Educational Resources Information Center

Byrnes, Vaughan; Ruby, Allen

2007-01-01

This study compares middle schools to K-8 schools, as well as to newly formed K-8 schools that are part of a K-8 conversion policy. The outcome is student achievement, and our sample includes 40,883 eighth-grade students from 95 schools across five cohorts. The analysis uses multilevel modeling to account for student, cohort, and school-level…

Poisson-process generalization for the trading waiting-time distribution in a double-auction mechanism

NASA Astrophysics Data System (ADS)

Cincotti, Silvano; Ponta, Linda; Raberto, Marco; Scalas, Enrico

2005-05-01

In this paper, empirical analyses and computational experiments are presented on high-frequency data for a double-auction (book) market. Main objective of the paper is to generalize the order waiting time process in order to properly model such empirical evidences. The empirical study is performed on the best bid and best ask data of 7 U.S. financial markets, for 30-stock time series. In particular, statistical properties of trading waiting times have been analyzed and quality of fits is evaluated by suitable statistical tests, i.e., comparing empirical distributions with theoretical models. Starting from the statistical studies on real data, attention has been focused on the reproducibility of such results in an artificial market. The computational experiments have been performed within the Genoa Artificial Stock Market. In the market model, heterogeneous agents trade one risky asset in exchange for cash. Agents have zero intelligence and issue random limit or market orders depending on their budget constraints. The price is cleared by means of a limit order book. The order generation is modelled with a renewal process. Based on empirical trading estimation, the distribution of waiting times between two consecutive orders is modelled by a mixture of exponential processes. Results show that the empirical waiting-time distribution can be considered as a generalization of a Poisson process. Moreover, the renewal process can approximate real data and implementation on the artificial stocks market can reproduce the trading activity in a realistic way.

Traveltime budgets and mobility in urban areas

DOT National Transportation Integrated Search

1974-05-01

The study tests by empirical comparative analysis the concept that tripmakers have a stable daily traveltime budget and discusses the implication of such a budget to transportation modeling techniques and the evaluation of alternative transportation ...

Renewing the model employer. Changing employment relations and "partnership" in the health and private sectors.

PubMed

Stuart, M; Martinez Lucio, M

2000-01-01

Drawing from original empirical data this paper compares the changing nature of employment relations in the health and private sectors. A key concern is to assess the extent to which the emergence of partnership-type arrangements between employers and trade unions lays the basis for the "renewal" of the traditional public sector concept of the model employer. Empirically, the paper draws on a survey of trade union representatives from 238 workplaces and a case study of a hospital trust. The data reveal that employment relations in the NHS are more collectivist when compared with the private sector. However, the development of partnership in the NHS is hamstrung by ongoing training and involvement gaps and widespread work intensification.

['Walkability' and physical activity - results of empirical studies based on the 'Neighbourhood Environment Walkability Scale (NEWS)'].

PubMed

Rottmann, M; Mielck, A

2014-02-01

'Walkability' is mainly assessed by the NEWS questionnaire (Neighbourhood Environment Walkability Scale); in Germany this questionnaire is widely unknown. We now try to fill this gap by providing a systematic overview of empirical studies based on the NEWS. A systematic review was conducted concerning original papers including empirical analyses based on the NEWS. The results are summarised and presented in tables. Altogether 31 publications could be identified. Most of them focus on associations with the variable 'physical activity', and they often report significant associations with at least some of the scales included in the NEWS. Due to methodological differences between the studies it is difficult to compare the results. The concept of 'walkability' should also be established in the German public health discussion. A number of methodological challenges remain to be solved, such as the identification of those scales and items in the NEWS that show the strongest associations with individual health behaviours. © Georg Thieme Verlag KG Stuttgart · New York.

Empiric antifungal therapy and outcomes in extremely low birth weight infants with invasive candidiasis.

PubMed

Greenberg, Rachel G; Benjamin, Daniel K; Gantz, Marie G; Cotten, C Michael; Stoll, Barbara J; Walsh, Michele C; Sánchez, Pablo J; Shankaran, Seetha; Das, Abhik; Higgins, Rosemary D; Miller, Nancy A; Auten, Kathy J; Walsh, Thomas J; Laptook, Abbot R; Carlo, Waldemar A; Kennedy, Kathleen A; Finer, Neil N; Duara, Shahnaz; Schibler, Kurt; Ehrenkranz, Richard A; Van Meurs, Krisa P; Frantz, Ivan D; Phelps, Dale L; Poindexter, Brenda B; Bell, Edward F; O'Shea, T Michael; Watterberg, Kristi L; Goldberg, Ronald N; Smith, P Brian

2012-08-01

To assess the impact of empiric antifungal therapy for invasive candidiasis on subsequent outcomes in premature infants. This was a cohort study of infants with a birth weight ≤ 1000 g receiving care at Neonatal Research Network sites. All infants had at least one positive culture for Candida. Empiric antifungal therapy was defined as receipt of a systemic antifungal on the day of or the day before the first positive culture for Candida was drawn. We created Cox proportional hazards and logistic regression models stratified on propensity score quartiles to determine the effect of empiric antifungal therapy on survival, time to clearance of infection, retinopathy of prematurity, bronchopulmonary dysplasia, end-organ damage, and neurodevelopmental impairment (NDI). A total of 136 infants developed invasive candidiasis. The incidence of death or NDI was lower in infants who received empiric antifungal therapy (19 of 38; 50%) compared with those who had not (55 of 86; 64%; OR, 0.27; 95% CI, 0.08-0.86). There was no significant difference between the groups for any single outcome or other combined outcomes. Empiric antifungal therapy was associated with increased survival without NDI. A prospective randomized trial of this strategy is warranted. Copyright © 2012 Mosby, Inc. All rights reserved.

Comparison of modelled and empirical atmospheric propagation data

NASA Technical Reports Server (NTRS)

Schott, J. R.; Biegel, J. D.

1983-01-01

The radiometric integrity of TM thermal infrared channel data was evaluated and monitored to develop improved radiometric preprocessing calibration techniques for removal of atmospheric effects. Modelled atmospheric transmittance and path radiance were compared with empirical values derived from aircraft underflight data. Aircraft thermal infrared imagery and calibration data were available on two dates as were corresponding atmospheric radiosonde data. The radiosonde data were used as input to the LOWTRAN 5A code which was modified to output atmospheric path radiance in addition to transmittance. The aircraft data were calibrated and used to generate analogous measurements. These data indicate that there is a tendancy for the LOWTRAN model to underestimate atmospheric path radiance and transmittance as compared to empirical data. A plot of transmittance versus altitude for both LOWTRAN and empirical data is presented.

Empirical likelihood-based confidence intervals for mean medical cost with censored data.

PubMed

Jeyarajah, Jenny; Qin, Gengsheng

2017-11-10

In this paper, we propose empirical likelihood methods based on influence function and jackknife techniques for constructing confidence intervals for mean medical cost with censored data. We conduct a simulation study to compare the coverage probabilities and interval lengths of our proposed confidence intervals with that of the existing normal approximation-based confidence intervals and bootstrap confidence intervals. The proposed methods have better finite-sample performances than existing methods. Finally, we illustrate our proposed methods with a relevant example. Copyright © 2017 John Wiley & Sons, Ltd.

Investigation of Organizational Interaction and Support in an NGO through Computer-Mediated Discussions

ERIC Educational Resources Information Center

Chang, Yao-Jen; Chang, Yao-Sheng

2011-01-01

Discussion forums have been used to support organizational communication and they have become a candidate for study of organizational behaviors. However, online behaviors of NGOs have been insufficiently studied compared to those studies conducted in education and industries. Our empirical study examined how social workers in one NGO used an…

A semi-empirical analysis of strong-motion peaks in terms of seismic source, propagation path, and local site conditions

NASA Astrophysics Data System (ADS)

Kamiyama, M.; Orourke, M. J.; Flores-Berrones, R.

1992-09-01

A new type of semi-empirical expression for scaling strong-motion peaks in terms of seismic source, propagation path, and local site conditions is derived. Peak acceleration, peak velocity, and peak displacement are analyzed in a similar fashion because they are interrelated. However, emphasis is placed on the peak velocity which is a key ground motion parameter for lifeline earthquake engineering studies. With the help of seismic source theories, the semi-empirical model is derived using strong motions obtained in Japan. In the derivation, statistical considerations are used in the selection of the model itself and the model parameters. Earthquake magnitude M and hypocentral distance r are selected as independent variables and the dummy variables are introduced to identify the amplification factor due to individual local site conditions. The resulting semi-empirical expressions for the peak acceleration, velocity, and displacement are then compared with strong-motion data observed during three earthquakes in the U.S. and Mexico.

An empirical study of statistical properties of variance partition coefficients for multi-level logistic regression models

USGS Publications Warehouse

Li, Ji; Gray, B.R.; Bates, D.M.

2008-01-01

Partitioning the variance of a response by design levels is challenging for binomial and other discrete outcomes. Goldstein (2003) proposed four definitions for variance partitioning coefficients (VPC) under a two-level logistic regression model. In this study, we explicitly derived formulae for multi-level logistic regression model and subsequently studied the distributional properties of the calculated VPCs. Using simulations and a vegetation dataset, we demonstrated associations between different VPC definitions, the importance of methods for estimating VPCs (by comparing VPC obtained using Laplace and penalized quasilikehood methods), and bivariate dependence between VPCs calculated at different levels. Such an empirical study lends an immediate support to wider applications of VPC in scientific data analysis.

Varieties of Organizational Conflict

ERIC Educational Resources Information Center

Pondy, Louis R.

1969-01-01

The viewpoints and findings of the seven empirical studies of organizational conflict contained in this issue are compared and contrasted. A distinction is made between conflict within a stable organization structure and conflict aimed at changing the organization structure. (Author)

Personality Traits: A View From the Animal Kingdom.

PubMed

Weiss, Alexander

2018-02-01

Given their backgrounds in classical ethology and in comparative psychology, researchers who study animal personality in biology and psychology, respectively, differ in how they measure personality, what questions they see as important, and how they address these questions. Despite these differences, both comparative psychologists and biologists embrace personality traits. By doing so, they have solved empirical and conceptual problems in animal behavior. Studies of animal personality have provided answers to questions about the evolution of human personality and have presented conceptual and empirical anomalies for sociocognitive theories. Animal personality research does not break from trait theories of personality. Instead, it enriches trait theories by conceiving of traits as not belonging to a species, but as expressed, with some modifications, across species. Broadening trait theory in this way has the potential to further enhance its ability to answer questions related to animal and human personality. © 2017 The Authors. Journal of Personality published by Wiley Periodicals, Inc.

Patients presenting to the hospital with MRSA pneumonia: differentiating characteristics and outcomes with empiric treatment.

PubMed

Minejima, Emi; Lou, Mimi; Nieberg, Paul; Wong-Beringer, Annie

2014-05-10

Concern for MRSA in patients presented to the hospital with pneumonia may be overestimated leading to excessive prescribing of empiric anti-MRSA therapy. This study aims to identify at-risk patients and treatment outcomes. Adults hospitalized during 2005-2011 with pneumonia diagnosed within 48 h of admission were included. Medical charts were retrospectively reviewed for relevant data. Patients with MRSA were matched 1:1 to those with non-MRSA pathogen or negative culture. A published risk scoring system for MRSA pneumonia was applied. 268 elderly patients were included, 134 patients in each group. Compared to non-MRSA group, MRSA patients presented more acutely ill (p < 0.0001) (pneumonia severity index score, 150 vs 93; vasopressor therapy, 34% vs 6%; ICU admission, 47% vs 13%; and mechanical ventilation, 35% vs 10%) and had worse outcomes (p < 0.0001) (time to reach clinical stability, 6 vs 2.5d; length of stay, 10 vs 5d; clinical failure, 28% vs 4%; 28-day mortality, 22% vs 3%). When applied to our patients, a published risk scoring scheme had 93% sensitivity but lacked specificity at 55%; 40% of medium-risk patients did not have MRSA. A history of MRSA infection or pneumonia differentiated the latter group. Most MRSA patients (66%, 88/134) were treated empirically (primarily vancomycin) but outcome was not improved by receipt of empiric therapy. Use of a published risk scoring scheme with additional variables from this study can potentially reduce overprescribing of anti-MRSA empiric therapy in patients presented to the hospital with pneumonia. Prospective studies evaluating the treatment benefit of non-vancomycin alternatives as empiric therapy are needed.

Patients presenting to the hospital with MRSA pneumonia: differentiating characteristics and outcomes with empiric treatment

PubMed Central

2014-01-01

Background Concern for MRSA in patients presented to the hospital with pneumonia may be overestimated leading to excessive prescribing of empiric anti-MRSA therapy. This study aims to identify at-risk patients and treatment outcomes. Methods Adults hospitalized during 2005–2011 with pneumonia diagnosed within 48 h of admission were included. Medical charts were retrospectively reviewed for relevant data. Patients with MRSA were matched 1:1 to those with non-MRSA pathogen or negative culture. A published risk scoring system for MRSA pneumonia was applied. Results 268 elderly patients were included, 134 patients in each group. Compared to non-MRSA group, MRSA patients presented more acutely ill (p < 0.0001) (pneumonia severity index score, 150 vs 93; vasopressor therapy, 34% vs 6%; ICU admission, 47% vs 13%; and mechanical ventilation, 35% vs 10%) and had worse outcomes (p < 0.0001) (time to reach clinical stability, 6 vs 2.5d; length of stay, 10 vs 5d; clinical failure, 28% vs 4%; 28-day mortality, 22% vs 3%). When applied to our patients, a published risk scoring scheme had 93% sensitivity but lacked specificity at 55%; 40% of medium-risk patients did not have MRSA. A history of MRSA infection or pneumonia differentiated the latter group. Most MRSA patients (66%, 88/134) were treated empirically (primarily vancomycin) but outcome was not improved by receipt of empiric therapy. Conclusions Use of a published risk scoring scheme with additional variables from this study can potentially reduce overprescribing of anti-MRSA empiric therapy in patients presented to the hospital with pneumonia. Prospective studies evaluating the treatment benefit of non-vancomycin alternatives as empiric therapy are needed. PMID:24885158

Migration confers winter survival benefits in a partially migratory songbird

PubMed Central

Zúñiga, Daniel; Gager, Yann; Kokko, Hanna; Fudickar, Adam Michael; Schmidt, Andreas; Naef-Daenzer, Beat; Wikelski, Martin

2017-01-01

To evolve and to be maintained, seasonal migration, despite its risks, has to yield fitness benefits compared with year-round residency. Empirical data supporting this prediction have remained elusive in the bird literature. To test fitness related benefits of migration, we studied a partial migratory population of European blackbirds (Turdus merula) over 7 years. Using a combination of capture-mark-recapture and radio telemetry, we compared survival probabilities between migrants and residents estimated by multi-event survival models, showing that migrant blackbirds had 16% higher probability to survive the winter compared to residents. A subsequent modelling exercise revealed that residents should have 61.25% higher breeding success than migrants, to outweigh the survival costs of residency. Our results support theoretical models that migration should confer survival benefits to evolve, and thus provide empirical evidence to understand the evolution and maintenance of migration. PMID:29157357

An Empirical Comparison of DDF Detection Methods for Understanding the Causes of DIF in Multiple-Choice Items

ERIC Educational Resources Information Center

Suh, Youngsuk; Talley, Anna E.

2015-01-01

This study compared and illustrated four differential distractor functioning (DDF) detection methods for analyzing multiple-choice items. The log-linear approach, two item response theory-model-based approaches with likelihood ratio tests, and the odds ratio approach were compared to examine the congruence among the four DDF detection methods.…

A Comparative Study of Mindfulness between Male and Female Intervarsity Taekwondo Players of India

ERIC Educational Resources Information Center

Rahaman, Abdul

2015-01-01

Mindfulness refers to being completely in touch with and aware of the present moment, as well as taking a non-evaluative and non-judgmental approach to one's inner experience. The present empirical investigation was conducted to compare the mindfulness of male and female intervarsity Taekwondo players of India. One hundred and four Taekwondo…

Comparing Virtual and Location-Based Augmented Reality Mobile Learning: Emotions and Learning Outcomes

ERIC Educational Resources Information Center

Harley, Jason M.; Poitras, Eric G.; Jarrell, Amanda; Duffy, Melissa C.; Lajoie, Susanne P.

2016-01-01

Research on the effectiveness of augmented reality (AR) on learning exists, but there is a paucity of empirical work that explores the role that positive emotions play in supporting learning in such settings. To address this gap, this study compared undergraduate students' emotions and learning outcomes during a guided historical tour using mobile…

Comparing timber and lumber from plantation and natural stands of ponderosa pine

Treesearch

Eini C. Lowell; Christine L. Todoroki; Ed. Thomas

2009-01-01

Data derived from empirical studies, coupled with modeling and simulation techniques, were used to compare tree and product quality from two stands of small-diameter ponderosa pine trees growing in northern California: one plantation, the other natural. The plantation had no management following establishment, and the natural stand had no active management. Fifty trees...

Data-driven regions of interest for longitudinal change in frontotemporal lobar degeneration.

PubMed

Pankov, Aleksandr; Binney, Richard J; Staffaroni, Adam M; Kornak, John; Attygalle, Suneth; Schuff, Norbert; Weiner, Michael W; Kramer, Joel H; Dickerson, Bradford C; Miller, Bruce L; Rosen, Howard J

2016-01-01

Current research is investigating the potential utility of longitudinal measurement of brain structure as a marker of drug effect in clinical trials for neurodegenerative disease. Recent studies in Alzheimer's disease (AD) have shown that measurement of change in empirically derived regions of interest (ROIs) allows more reliable measurement of change over time compared with regions chosen a-priori based on known effects of AD on brain anatomy. Frontotemporal lobar degeneration (FTLD) is a devastating neurodegenerative disorder for which there are no approved treatments. The goal of this study was to identify an empirical ROI that maximizes the effect size for the annual rate of brain atrophy in FTLD compared with healthy age matched controls, and to estimate the effect size and associated power estimates for a theoretical study that would use change within this ROI as an outcome measure. Eighty six patients with FTLD were studied, including 43 who were imaged twice at 1.5 T and 43 at 3 T, along with 105 controls (37 imaged at 1.5 T and 67 at 3 T). Empirically-derived maps of change were generated separately for each field strength and included the bilateral insula, dorsolateral, medial and orbital frontal, basal ganglia and lateral and inferior temporal regions. The extent of regions included in the 3 T map was larger than that in the 1.5 T map. At both field strengths, the effect sizes for imaging were larger than for any clinical measures. At 3 T, the effect size for longitudinal change measured within the empirically derived ROI was larger than the effect sizes derived from frontal lobe, temporal lobe or whole brain ROIs. The effect size derived from the data-driven 1.5 T map was smaller than at 3 T, and was not larger than the effect size derived from a-priori ROIs. It was estimated that measurement of longitudinal change using 1.5 T MR systems requires approximately a 3-fold increase in sample size to obtain effect sizes equivalent to those seen at 3 T. While the results should be confirmed in additional datasets, these results indicate that empirically derived ROIs can reduce the number of subjects needed for a longitudinal study of drug effects in FTLD compared with a-priori ROIs. Field strength may have a significant impact on the utility of imaging for measuring longitudinal change.

Is There a Role for Empiric Gastroduodenal Artery Embolization in the Management of Patients with Active Upper GI Hemorrhage?

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

Dixon, Shaheen, E-mail: shaheen7noorani@gmail.com; Chan, Victoria, E-mail: dr.victoriac@gmail.com; Shrivastava, Vivek, E-mail: vivshriv@yahoo.com

2013-08-01

PurposeTo assess the relative efficacy of empiric gastroduodenal artery (GDA) embolization in reducing recurrent hemorrhage compared to image-guided targeted embolization.MethodsData were retrospectively collected for consecutive patients who had catheter angiography for major upper gastrointestinal hemorrhage from May 2008 to November 2010 (n = 40). The total number of cases were divided into two main groups according to angiographic findings: those that demonstrated a site of hemorrhage on catheter angiography (group 1, n = 13), and those where the site of hemorrhage was not identified on catheter angiography (group 2, n = 27). Group 2 was then further divided into patientsmore » who received empiric embolization (group 2a, n = 20) and those who had no embolization performed after angiography (group 2b, n = 7).ResultsThe technical and clinical success rates for embolization in groups 1 and 2a were, respectively, 100 vs. 95 %, and 85 vs. 80 %. There was no statistical significance in the recurrent hemorrhage rate, reintervention rate, or 30 day mortality between targeted and empiric embolization groups. There were no complications attributed to embolization within this study cohort.ConclusionCases of duodenal-related major upper gastrointestinal hemorrhage where no embolization is performed have poor outcome. Empiric embolization of the GDA in patients with major upper gastrointestinal hemorrhage refractory to endoscopic treatment appears to be a safe and effective treatment, with low reintervention rates and good clinical outcome comparable to patients where the site of hemorrhage is localized and embolized with computed tomographic angiography or catheter angiography and embolized.« less

Bacterial clonal diagnostics as a tool for evidence-based empiric antibiotic selection

PubMed Central

Tchesnokova, Veronika; Avagyan, Hovhannes; Rechkina, Elena; Chan, Diana; Muradova, Mariya; Haile, Helen Ghirmai; Radey, Matthew; Weissman, Scott; Riddell, Kim; Scholes, Delia; Johnson, James R.

2017-01-01

Despite the known clonal distribution of antibiotic resistance in many bacteria, empiric (pre-culture) antibiotic selection still relies heavily on species-level cumulative antibiograms, resulting in overuse of broad-spectrum agents and excessive antibiotic/pathogen mismatch. Urinary tract infections (UTIs), which account for a large share of antibiotic use, are caused predominantly by Escherichia coli, a highly clonal pathogen. In an observational clinical cohort study of urgent care patients with suspected UTI, we assessed the potential for E. coli clonal-level antibiograms to improve empiric antibiotic selection. A novel PCR-based clonotyping assay was applied to fresh urine samples to rapidly detect E. coli and the urine strain's clonotype. Based on a database of clonotype-specific antibiograms, the acceptability of various antibiotics for empiric therapy was inferred using a 20%, 10%, and 30% allowed resistance threshold. The test's performance characteristics and possible effects on prescribing were assessed. The rapid test identified E. coli clonotypes directly in patients’ urine within 25–35 minutes, with high specificity and sensitivity compared to culture. Antibiotic selection based on a clonotype-specific antibiogram could reduce the relative likelihood of antibiotic/pathogen mismatch by ≥ 60%. Compared to observed prescribing patterns, clonal diagnostics-guided antibiotic selection could safely double the use of trimethoprim/sulfamethoxazole and minimize fluoroquinolone use. In summary, a rapid clonotyping test showed promise for improving empiric antibiotic prescribing for E. coli UTI, including reversing preferential use of fluoroquinolones over trimethoprim/sulfamethoxazole. The clonal diagnostics approach merges epidemiologic surveillance, antimicrobial stewardship, and molecular diagnostics to bring evidence-based medicine directly to the point of care. PMID:28350870

Bacterial clonal diagnostics as a tool for evidence-based empiric antibiotic selection.

PubMed

Tchesnokova, Veronika; Avagyan, Hovhannes; Rechkina, Elena; Chan, Diana; Muradova, Mariya; Haile, Helen Ghirmai; Radey, Matthew; Weissman, Scott; Riddell, Kim; Scholes, Delia; Johnson, James R; Sokurenko, Evgeni V

2017-01-01

Despite the known clonal distribution of antibiotic resistance in many bacteria, empiric (pre-culture) antibiotic selection still relies heavily on species-level cumulative antibiograms, resulting in overuse of broad-spectrum agents and excessive antibiotic/pathogen mismatch. Urinary tract infections (UTIs), which account for a large share of antibiotic use, are caused predominantly by Escherichia coli, a highly clonal pathogen. In an observational clinical cohort study of urgent care patients with suspected UTI, we assessed the potential for E. coli clonal-level antibiograms to improve empiric antibiotic selection. A novel PCR-based clonotyping assay was applied to fresh urine samples to rapidly detect E. coli and the urine strain's clonotype. Based on a database of clonotype-specific antibiograms, the acceptability of various antibiotics for empiric therapy was inferred using a 20%, 10%, and 30% allowed resistance threshold. The test's performance characteristics and possible effects on prescribing were assessed. The rapid test identified E. coli clonotypes directly in patients' urine within 25-35 minutes, with high specificity and sensitivity compared to culture. Antibiotic selection based on a clonotype-specific antibiogram could reduce the relative likelihood of antibiotic/pathogen mismatch by ≥ 60%. Compared to observed prescribing patterns, clonal diagnostics-guided antibiotic selection could safely double the use of trimethoprim/sulfamethoxazole and minimize fluoroquinolone use. In summary, a rapid clonotyping test showed promise for improving empiric antibiotic prescribing for E. coli UTI, including reversing preferential use of fluoroquinolones over trimethoprim/sulfamethoxazole. The clonal diagnostics approach merges epidemiologic surveillance, antimicrobial stewardship, and molecular diagnostics to bring evidence-based medicine directly to the point of care.

Efficacy of sequential three-step empirical therapy for chronic cough.

PubMed

Yu, Li; Xu, Xianghuai; Hang, Jingqing; Cheng, Kewen; Jin, Xiaoyan; Chen, Qiang; Lv, Hanjing; Qiu, Zhongmin

2017-06-01

Empirical three-step therapy has been proved in just one hospital. This study aimed to demonstrate applicability of the sequential empirical three-step therapy for chronic cough in different clinical settings. Sequential empirical three-step therapy was given to patients with chronic cough in one tertiary and three secondary care respiratory clinics. Recruiters were initially treated with methoxyphenamine compound as the first-step therapy, followed by corticosteroids as the second-step therapy and the combination of a proton-pump inhibitor and a prokinetic agent as the third-step therapy. The efficacy of the therapy was verified according to the changes in cough symptom score between pre- and post-treatment, and compared among the different clinics. In total 155 patients in one tertiary clinic and 193 patients in secondary care clinics were recruited. The total dropout ratio is significantly higher in the secondary care clinics than that in the tertiary clinic (9.3% versus 3.2%, p = 0.023). The therapeutic success rate for cough was 38.7% at first-step therapy, 32.3% at second-step therapy and 20.0% at third-step therapy in the tertiary clinic, and comparable to corresponding 49.7%, 31.1% and 4.1% in secondary care clinics. Furthermore, the overall cough resolution rate was not significantly different (91.0% versus 85.0%, p = 0.091). However, the efficacy of the third-step therapy is much higher (20.0% versus 4.1%, p = 0.001) in the tertiary clinic than in the secondary care clinics. Sequential empirical three-step therapy is universally efficacious and useful for management of chronic cough in different clinical settings.

A Simulation Study Comparing Epidemic Dynamics on Exponential Random Graph and Edge-Triangle Configuration Type Contact Network Models

PubMed Central

Rolls, David A.; Wang, Peng; McBryde, Emma; Pattison, Philippa; Robins, Garry

2015-01-01

We compare two broad types of empirically grounded random network models in terms of their abilities to capture both network features and simulated Susceptible-Infected-Recovered (SIR) epidemic dynamics. The types of network models are exponential random graph models (ERGMs) and extensions of the configuration model. We use three kinds of empirical contact networks, chosen to provide both variety and realistic patterns of human contact: a highly clustered network, a bipartite network and a snowball sampled network of a “hidden population”. In the case of the snowball sampled network we present a novel method for fitting an edge-triangle model. In our results, ERGMs consistently capture clustering as well or better than configuration-type models, but the latter models better capture the node degree distribution. Despite the additional computational requirements to fit ERGMs to empirical networks, the use of ERGMs provides only a slight improvement in the ability of the models to recreate epidemic features of the empirical network in simulated SIR epidemics. Generally, SIR epidemic results from using configuration-type models fall between those from a random network model (i.e., an Erdős-Rényi model) and an ERGM. The addition of subgraphs of size four to edge-triangle type models does improve agreement with the empirical network for smaller densities in clustered networks. Additional subgraphs do not make a noticeable difference in our example, although we would expect the ability to model cliques to be helpful for contact networks exhibiting household structure. PMID:26555701

Empiric Antibiotic Use and Susceptibility in Infants With Bacterial Infections: A Multicenter Retrospective Cohort Study.

PubMed

Feldman, Elana A; McCulloh, Russell J; Myers, Angela L; Aronson, Paul L; Neuman, Mark I; Bradford, Miranda C; Alpern, Elizabeth R; Balamuth, Frances; Blackstone, Mercedes M; Browning, Whitney L; Hayes, Katie; Korman, Rosalynne; Leazer, Rianna C; Nigrovic, Lise E; Marble, Richard; Roben, Emily; Williams, Derek J; Tieder, Joel S

2017-07-20

To assess hospital differences in empirical antibiotic use, bacterial epidemiology, and antimicrobial susceptibility for common antibiotic regimens among young infants with urinary tract infection (UTI), bacteremia, or bacterial meningitis. We reviewed medical records from infants <90 days old presenting to 8 US children's hospitals with UTI, bacteremia, or meningitis. We used the Pediatric Health Information System database to identify cases and empirical antibiotic use and medical record review to determine infection, pathogen, and antimicrobial susceptibility patterns. We compared hospital-level differences in antimicrobial use, pathogen, infection site, and antimicrobial susceptibility. We identified 470 infants with bacterial infections: 362 (77%) with UTI alone and 108 (23%) with meningitis or bacteremia. Infection type did not differ across hospitals ( P = .85). Empirical antibiotic use varied across hospitals ( P < .01), although antimicrobial susceptibility patterns for common empirical regimens were similar. A third-generation cephalosporin would have empirically treated 90% of all ages, 89% in 7- to 28-day-olds, and 91% in 29- to 89-day-olds. The addition of ampicillin would have improved coverage in only 4 cases of bacteremia and meningitis. Ampicillin plus gentamicin would have treated 95%, 89%, and 97% in these age groups, respectively. Empirical antibiotic use differed across regionally diverse US children's hospitals in infants <90 days old with UTI, bacteremia, or meningitis. Antimicrobial susceptibility to common antibiotic regimens was similar across hospitals, and adding ampicillin to a third-generation cephalosporin minimally improves coverage. Our findings support incorporating empirical antibiotic recommendations into national guidelines for infants with suspected bacterial infection. Copyright © 2017 by the American Academy of Pediatrics.

The role of hip and chest radiographs in osteoporotic evaluation among south Indian women population: a comparative scenario with DXA.

PubMed

Kumar, D Ashok; Anburajan, M

2014-05-01

Osteoporosis is recognized as a worldwide skeletal disorder problem. In India, the older as well as postmenopausal women population suffering from osteoporotic fractures has been a common issue. Bone mineral density measurements gauged by dual-energy X-ray absorptiometry (DXA) are used in the diagnosis of osteoporosis. (1) To evaluate osteoporosis in south Indian women by radiogrammetric method in a comparative perspective with DXA. (2) To assess the capability of KJH; Anburajan's Empirical formula in the prediction of total hip bone mineral density (T.BMD) with estimated Hologic T.BMD. In this cross-sectional design, 56 south Indian women were evaluated. These women were randomly selected from a health camp. The patients with secondary bone diseases were excluded. The standard protocol was followed in acquiring BMD of the right proximal femur by DPX Prodigy (DXA Scanner, GE-Lunar Corp., USA). The measured Lunar Total hip BMD was converted into estimated Hologic Total hip BMD. In addition, the studied population underwent chest and hip radiographic measurements. Combined cortical thickness of clavicle has been used in KJH; Anburajan's Empirical formula to predict T.BMD and compared with estimated Hologic T.BMD by DXA. The correlation coefficients exhibited high significance. The combined cortical thickness of clavicle and femur shaft of total studied population was strongly correlated with DXA femur T.BMD measurements (r = 0.87, P < 0.01 and r = 0.45, P < 0.01) and it is also having strong correlation with low bone mass group (r = 0.87, P < 0.01 and r = 0.67, P < 0.01) KJH; Anburajan's Empirical formula shows significant correlation with estimated Hologic T.BMD (r = 0.88, P < 0.01) in total studied population. The empirical formula was identified as better tool for predicting osteoporosis in total population and old-aged population with a sensitivity (88.8 and 95.6 %), specificity (89.6 and 90.9 %), positive predictive value (88.8 and 95.6 %) and negative predictive value (89.6 and 90.9 %), respectively. The results suggest that combined cortical thickness of clavicle and femur shaft using radiogrammetric method is significantly correlated with DXA. Moreover, KJH; Anburajan's Empirical formula is useful and better index than other simple radiogrammetry measurements in the evaluation of osteoporosis from the economical and widely available digital radiographs.

Evidence-based Nursing Education - a Systematic Review of Empirical Research

PubMed Central

Reiber, Karin

2011-01-01

The project „Evidence-based Nursing Education – Preparatory Stage“, funded by the Landesstiftung Baden-Württemberg within the programme Impulsfinanzierung Forschung (Funding to Stimulate Research), aims to collect information on current research concerned with nursing education and to process existing data. The results of empirical research which has already been carried out were systematically evaluated with aim of identifying further topics, fields and matters of interest for empirical research in nursing education. In the course of the project, the available empirical studies on nursing education were scientifically analysed and systematised. The over-arching aim of the evidence-based training approach – which extends beyond the aims of this project - is the conception, organisation and evaluation of vocational training and educational processes in the caring professions on the basis of empirical data. The following contribution first provides a systematic, theoretical link to the over-arching reference framework, as the evidence-based approach is adapted from thematically related specialist fields. The research design of the project is oriented towards criteria introduced from a selection of studies and carries out a two-stage systematic review of the selected studies. As a result, the current status of research in nursing education, as well as its organisation and structure, and questions relating to specialist training and comparative education are introduced and discussed. Finally, the empirical research on nursing training is critically appraised as a complementary element in educational theory/psychology of learning and in the ethical tradition of research. This contribution aims, on the one hand, to derive and describe the methods used, and to introduce the steps followed in gathering and evaluating the data. On the other hand, it is intended to give a systematic overview of empirical research work in nursing education. In order to preserve a holistic view of the research field and methods, detailed individual findings are not included. PMID:21818237

Socioscientific Issues in Science Education: The Case of Turkey

ERIC Educational Resources Information Center

Topcu, Mustafa Sami; Mugaloglu, Ebru Zeynep; Guven, Devrim

2014-01-01

The purpose of this study is to identify the foci and results of studies on socioscientific issues (SSI) conducted in Turkey. Additionally, the study aimed to compare the results of this study with ones conducted internationally. For this aim, a literary review of empirical studies related to SSI conducted in Turkey was carried out. Four criteria…

Modeling the erythemal surface diffuse irradiance fraction for Badajoz, Spain

NASA Astrophysics Data System (ADS)

Sanchez, Guadalupe; Serrano, Antonio; Cancillo, María Luisa

2017-10-01

Despite its important role on the human health and numerous biological processes, the diffuse component of the erythemal ultraviolet irradiance (UVER) is scarcely measured at standard radiometric stations and therefore needs to be estimated. This study proposes and compares 10 empirical models to estimate the UVER diffuse fraction. These models are inspired from mathematical expressions originally used to estimate total diffuse fraction, but, in this study, they are applied to the UVER case and tested against experimental measurements. In addition to adapting to the UVER range the various independent variables involved in these models, the total ozone column has been added in order to account for its strong impact on the attenuation of ultraviolet radiation. The proposed models are fitted to experimental measurements and validated against an independent subset. The best-performing model (RAU3) is based on a model proposed by Ruiz-Arias et al. (2010) and shows values of r2 equal to 0.91 and relative root-mean-square error (rRMSE) equal to 6.1 %. The performance achieved by this entirely empirical model is better than those obtained by previous semi-empirical approaches and therefore needs no additional information from other physically based models. This study expands on previous research to the ultraviolet range and provides reliable empirical models to accurately estimate the UVER diffuse fraction.

Initial therapeutic strategy of invasive candidiasis for intensive care unit patients: a retrospective analysis from the China-SCAN study.

PubMed

Cui, Na; Wang, Hao; Su, Longxiang; Qiu, Haibo; Li, Ruoyu; Liu, Dawei

2017-01-23

To investigate the impact of initial antifungal therapeutic strategies on the prognosis of invasive Candida infections (ICIs) in intensive care units (ICUs) in China. A total of 306 patients with proven ICIs in the China-SCAN study were analyzed retrospectively. Empiric, pre-emptive, and targeted therapy were adopted based on starting criteria including clinical, microbiological, and other conventional prediction rules. The primary outcome was hospital mortality and the secondary endpoints were duration days in ICU and duration days in hospital. The global responses (clinical and microbiological) at the end of the empirical therapy were also assessed. A total of 268/306 (87.6%) ICI patients received antifungal therapy, including 142/268 (53.0%) initial empirical therapy, 53/268 (19.8%) initial pre-emptive therapy, and 73/268 (27.2%) initial targeted therapy. Compared with the initial empirical antifungal therapy and targeted antifungal therapy, patients with initial pre-emptive antifungal therapy had significantly less clinical remission [11/53 (21.2%) vs. 61/142 (43.3%) vs. 22/73 (30.1%), P = 0.009], higher ICU [26/53 (57.8%) vs. 42/142 (32.2%) vs. 27/73 (43.5%), P = 0.008] and hospital mortality [27/53 (60.0%) vs. 43/142 (32.8%) vs. 29/73 (46.8%), P = 0.004] and more microbiological persistence [9/53 (17.0%) vs. 6/142 (4.2%) vs. 9/73 (12.3%), P = 0.011]. Kaplan-Meier survival analysis revealed that ICI patients with initial pre-emptive antifungal therapy and targeted antifungal therapy were associated with reduced hospital duration compared with patients with initial empirical antifungal therapy after confirmation of fungal infection (log-rank test: P = 0.021). Multivariate regression analysis provided evidence that initial empirical antifungal therapy was an independent predictor for DECREASING the hospital mortality in ICI patients on ICU admission and at ICI diagnosis (odds ratio 0.327, 95% confidence interval 0.160-0.667, P = 0.002; odds ratio 0.351, 95% confidence interval 0.168-0.735, P = 0.006). The initial therapeutic strategy for invasive candidiasis was independently associated with hospital mortality. Prompt empirical antifungal therapy could be critical to decrease early hospital mortality. Clinicaltrials.gov NCT01253954 (retrospectively registration date: December 3, 2010).

Investigation of 14-15 MeV ( n, t) Reaction Cross-sections by Using New Evaluated Empirical and Semi-empirical Systematic Formulas

NASA Astrophysics Data System (ADS)

Tel, E.; Aydın, A.; Kaplan, A.; Şarer, B.

2008-09-01

In the hybrid reactor, tritium self-sufficiency must be maintained for a commercial power plant. For self-sustaining (D-T) fusion driver tritium breeding ratio should be greater than 1.05. Working out the systematics of ( n, t) reaction cross-sections are of great importance for the definition of the excitation function character for the given reaction taking place on various nuclei at energies up to 20 MeV. In this study we have investigated asymmetry term effect for the ( n, t) reaction cross-sections at 14-15 neutron incident energy. It has been discussed the odd-even effect and the pairing effect considering binding energy systematic of the nuclear shell model for the new experimental data and new cross-sections formulas ( n, t) reactions developed by Tel et al. We have determined a different parameter groups by the classification of nuclei into even-even, even-odd and odd-even for ( n, t) reactions cross-sections. The obtained empirical and semi-empirical formulas by fitting two parameter for ( n, t) reactions were given. All calculated results have been compared with the experimental data and the other semi-empirical formulas.

The Study of Rain Specific Attenuation for the Prediction of Satellite Propagation in Malaysia

NASA Astrophysics Data System (ADS)

Mandeep, J. S.; Ng, Y. Y.; Abdullah, H.; Abdullah, M.

2010-06-01

Specific attenuation is the fundamental quantity in the calculation of rain attenuation for terrestrial path and slant paths representing as rain attenuation per unit distance (dB/km). Specific attenuation is an important element in developing the predicted rain attenuation model. This paper deals with the empirical determination of the power law coefficients which allow calculating the specific attenuation in dB/km from the knowledge of the rain rate in mm/h. The main purpose of the paper is to obtain the coefficients of k and α of power law relationship between specific attenuation. Three years (from 1st January 2006 until 31st December 2008) rain gauge and beacon data taken from USM, Nibong Tebal have been used to do the empirical procedure analysis of rain specific attenuation. The data presented are semi-empirical in nature. A year-to-year variation of the coefficients has been indicated and the empirical measured data was compared with ITU-R provided regression coefficient. The result indicated that the USM empirical measured data was significantly vary from ITU-R predicted value. Hence, ITU-R recommendation for regression coefficients of rain specific attenuation is not suitable for predicting rain attenuation at Malaysia.

Young Adult Educational and Vocational Outcomes of Children Diagnosed with ADHD

ERIC Educational Resources Information Center

Kuriyan, Aparajita B.; Pelham, William E., Jr.; Molina, Brooke S. G.; Waschbusch, Daniel A.; Gnagy, Elizabeth M.; Sibley, Margaret H.; Babinski, Dara E.; Walther, Christine; Cheong, JeeWon; Yu, Jihnhee; Kent, Kristine M.

2013-01-01

Decreased success at work and educational attainment by adulthood are of concern for children with ADHD given their widely documented academic difficulties; however there are few studies that have examined this empirically and even fewer that have studied predictors and individual variability of these outcomes. The current study compares young…

Technologies for Foreign Language Learning: A Review of Technology Types and Their Effectiveness

ERIC Educational Resources Information Center

Golonka, Ewa M.; Bowles, Anita R.; Frank, Victor M.; Richardson, Dorna L.; Freynik, Suzanne

2014-01-01

This review summarizes evidence for the effectiveness of technology use in foreign language (FL) learning and teaching, with a focus on empirical studies that compare the use of newer technologies with more traditional methods or materials. The review of over 350 studies (including classroom-based technologies, individual study tools,…

The Development of Transnational Higher Education in China: A Comparative Study of Research Universities and Teaching Universities

ERIC Educational Resources Information Center

Fang, Wenhong

2012-01-01

This article presents an empirical study of transnational higher education in China at the institutional level. The units of analysis are the Chinese partner universities of transnational higher education programs. Through comparison of research universities and teaching universities, the study finds that transnational higher education programs…

Comparing Multidimensional and Continuum Models of Vocabulary Acquisition: An Empirical Examination of the Vocabulary Knowledge Scale

ERIC Educational Resources Information Center

Stewart, Jeffrey; Batty, Aaron Olaf; Bovee, Nicholas

2012-01-01

Second language vocabulary acquisition has been modeled both as multidimensional in nature and as a continuum wherein the learner's knowledge of a word develops along a cline from recognition through production. In order to empirically examine and compare these models, the authors assess the degree to which the Vocabulary Knowledge Scale (VKS;…

ESTIMATING IMPERVIOUS COVER FROM REGIONALLY AVAILABLE DATA

EPA Science Inventory

The objective of this study is to compare and evaluate the reliability of different approaches for estimating impervious cover including three empirical formulations for estimating impervious cover from population density data, estimation from categorized land cover data, and to ...

Multicenter Retrospective Study of Cefmetazole and Flomoxef for Treatment of Extended-Spectrum-β-Lactamase-Producing Escherichia coli Bacteremia

PubMed Central

Yamamoto, Masaki; Nagao, Miki; Komori, Toshiaki; Fujita, Naohisa; Hayashi, Akihiko; Shimizu, Tsunehiro; Watanabe, Harumi; Doi, Shoichi; Tanaka, Michio; Takakura, Shunji; Ichiyama, Satoshi

2015-01-01

The efficacy of cefmetazole and flomoxef (CF) for the treatment of patients with extended-spectrum β-lactamase-producing Escherichia coli (ESBL-EC) bacteremia (ESBL-CF group) was compared with that of carbapenem treatment for ESBL-EC patients (ESBL-carbapenem group) and with that of CF treatment in patients with non-ESBL-EC bacteremia (non-ESBL-CF group). Adult patients treated for E. coli bacteremia in four hospitals were retrospectively evaluated. The 30-day mortality rates in patients belonging to the ESBL-CF, ESBL-carbapenem, and non-ESBL-CF groups were compared as 2 (empirical and definitive therapy) cohorts. The adjusted hazard ratios (aHRs) for mortality were calculated using Cox regression models with weighting according to the inverse probability of propensity scores for receiving CF or carbapenem treatment. The empirical-therapy cohort included 104 patients (ESBL-CF, 26; ESBL-carbapenem, 45; non-ESBL-CF, 33), and the definitive-therapy cohort included 133 patients (ESBL-CF, 59; ESBL-carbapenem, 54; non-ESBL-CF, 20). The crude 30-day mortality rates for patients in the ESBL-CF, ESBL-carbapenem, and non-ESBL-CF groups were, respectively, 7.7%, 8.9%, and 3.0% in the empirical-therapy cohort and 5.1%, 9.3%, and 5.0% in the definitve-therapy cohort. In patients without hematological malignancy and neutropenia, CF treatment for ESBL-EC patients was not associated with mortality compared with carbapenem treatment (empirical-therapy cohort: aHR, 0.87; 95% confidence interval [CI], 0.11 to 6.52; definitive therapy cohort: aHR, 1.04; CI, 0.24 to 4.49). CF therapy may represent an effective alternative to carbapenem treatment for patients with ESBL-EC bacteremia for empirical and definitive therapy in adult patients who do not have hematological malignancy and neutropenia. PMID:26100708

Multicenter retrospective study of cefmetazole and flomoxef for treatment of extended-spectrum-β-lactamase-producing Escherichia coli bacteremia.

PubMed

Matsumura, Yasufumi; Yamamoto, Masaki; Nagao, Miki; Komori, Toshiaki; Fujita, Naohisa; Hayashi, Akihiko; Shimizu, Tsunehiro; Watanabe, Harumi; Doi, Shoichi; Tanaka, Michio; Takakura, Shunji; Ichiyama, Satoshi

2015-09-01

The efficacy of cefmetazole and flomoxef (CF) for the treatment of patients with extended-spectrum β-lactamase-producing Escherichia coli (ESBL-EC) bacteremia (ESBL-CF group) was compared with that of carbapenem treatment for ESBL-EC patients (ESBL-carbapenem group) and with that of CF treatment in patients with non-ESBL-EC bacteremia (non-ESBL-CF group). Adult patients treated for E. coli bacteremia in four hospitals were retrospectively evaluated. The 30-day mortality rates in patients belonging to the ESBL-CF, ESBL-carbapenem, and non-ESBL-CF groups were compared as 2 (empirical and definitive therapy) cohorts. The adjusted hazard ratios (aHRs) for mortality were calculated using Cox regression models with weighting according to the inverse probability of propensity scores for receiving CF or carbapenem treatment. The empirical-therapy cohort included 104 patients (ESBL-CF, 26; ESBL-carbapenem, 45; non-ESBL-CF, 33), and the definitive-therapy cohort included 133 patients (ESBL-CF, 59; ESBL-carbapenem, 54; non-ESBL-CF, 20). The crude 30-day mortality rates for patients in the ESBL-CF, ESBL-carbapenem, and non-ESBL-CF groups were, respectively, 7.7%, 8.9%, and 3.0% in the empirical-therapy cohort and 5.1%, 9.3%, and 5.0% in the definitve-therapy cohort. In patients without hematological malignancy and neutropenia, CF treatment for ESBL-EC patients was not associated with mortality compared with carbapenem treatment (empirical-therapy cohort: aHR, 0.87; 95% confidence interval [CI], 0.11 to 6.52; definitive therapy cohort: aHR, 1.04; CI, 0.24 to 4.49). CF therapy may represent an effective alternative to carbapenem treatment for patients with ESBL-EC bacteremia for empirical and definitive therapy in adult patients who do not have hematological malignancy and neutropenia. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

The effectiveness of targeted relative to empiric prophylaxis on infectious complications after transrectal ultrasound-guided prostate biopsy: a meta-analysis.

PubMed

Scott, Susan; Harris, Patrick N; Williamson, Deborah A; Liss, Michael A; Doi, Suhail A R; Roberts, Matthew J

2018-07-01

Rectal culture screening for fluoroquinolone (FQ)-resistant Enterobacteriaceae before transrectal ultrasound guided prostate (TRUSPB) biopsy and targeted antibiotic prophylaxis (TAP) may decrease post-TRUSPB infection rates compared to empiric (EAP) regimens. The objective of this study was to evaluate the effectiveness of targeted relative to empiric prophylaxis regimens on rates of infectious complications after TRUSPB and to determine the baseline prevalence of FQ resistance based on prior rectal swabs. An electronic search within literature databases including EMBASE and Web of Science (all databases) for articles assessing TAP as an approach to TRUSPB prophylaxis was conducted. Quality assessment was performed using the Hoy instrument. Meta-analysis was performed using MetaXL 5.3. From 15 studies (eight retrospective and seven prospective) representing 12,320 participants, infectious complication incidence was 3.4% in EAP and 0.8% in TAP patients. The number needed to treat with TAP to avoid one more infection when compared to the EAP group was 39. Effect sizes were homogeneous. Prevalence of FQ resistance showed low (15%) and high (28%) subgroups, likely due to region of origin (within and outside USA, respectively). Rectal culture prior to TRUSPB and use of TAP adjusts for endemic FQ resistance and is associated with less infectious complications and resulting morbidity when compared to EAP. Overtreatment associated with augmented prophylaxis approaches may be reduced as a result. Further prospective assessment and cost-benefit analyses are required before widespread implementation can be recommended.

Suitability of Synthetic Driving Profiles from Traffic Micro-Simulation for Real-World Energy Analysis: Preprint

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

Hou, Yunfei; Wood, Eric; Burton, Evan

A shift towards increased levels of driving automation is generally expected to result in improved safety and traffic congestion outcomes. However, little empirical data exists to estimate the impact that automated driving could have on energy consumption and greenhouse gas emissions. In the absence of empirical data on differences between drive cycles from present day vehicles (primarily operated by humans) and future vehicles (partially or fully operated by computers) one approach is to model both situations over identical traffic conditions. Such an exercise requires traffic micro-simulation to not only accurately model vehicle operation under high levels of automation, but alsomore » (and potentially more challenging) vehicle operation under present day human drivers. This work seeks to quantify the ability of a commercial traffic micro-simulation program to accurately model real-world drive cycles in vehicles operated primarily by humans in terms of driving speed, acceleration, and simulated fuel economy. Synthetic profiles from models of freeway and arterial facilities near Atlanta, Georgia, are compared to empirical data collected from real-world drivers on the same facilities. Empirical and synthetic drive cycles are then simulated in a powertrain efficiency model to enable comparison on the basis of fuel economy. Synthetic profiles from traffic micro-simulation were found to exhibit low levels of transient behavior relative to the empirical data. Even with these differences, the synthetic and empirical data in this study agree well in terms of driving speed and simulated fuel economy. The differences in transient behavior between simulated and empirical data suggest that larger stochastic contributions in traffic micro-simulation (relative to those present in the traffic micro-simulation tool used in this study) are required to fully capture the arbitrary elements of human driving. Interestingly, the lack of stochastic contributions from models of human drivers in this study did not result in a significant discrepancy between fuel economy simulations based on synthetic and empirical data; a finding with implications on the potential energy efficiency gains of automated vehicle technology.« less

Linking Mechanisms of Work-Family Conflict and Segmentation

ERIC Educational Resources Information Center

Michel, Jesse S.; Hargis, Michael B.

2008-01-01

Despite the abundance of work and family research, few studies have compared the linking mechanisms specified in theoretical models of work-family conflict and segmentation. Accordingly, the current study provides a greater degree of empirical clarity concerning the interplay of work and family by directly examining the indirect effects of…

Escaping the Dusty Shelf: Legislative Evaluation Offices' Efforts to Promote Utilization

ERIC Educational Resources Information Center

Vanlandingham, Gary R.

2011-01-01

Although scholars have proposed many steps to increase evaluation use, there has been little comparative empirical study of whether researchers follow these recommendations and whether specific steps are associated with greater utilization. This study of state legislative evaluators finds that those that regularly meet with stakeholders and…

Comparative, Population-Level Analysis of Social Networks in Organizations

ERIC Educational Resources Information Center

Jacobs, Abigail Z.

2017-01-01

As social behavior moves increasingly online, the study of social behavior has followed. Online traces of social systems, whether to study online behavior directly or the online traces of offline activity, have made possible previously unavailable empirical analyses of people, groups and organizations. However, practically observing any social…

Spanish Journalists' Perception about Their Professional Roles

ERIC Educational Resources Information Center

Berganza, Rosa; Lavín, Eva; Piñeiro-Naval, Valeriano

2017-01-01

International empirical research on the perception that journalists have of their professional roles and functions has increased considerably in recent years, although not in the case of Spain. The present research, included within the transnational comparative study "The Worlds of Journalism Study", analyses data from a survey conducted…

A Meta-Analysis of Motivational Interviewing: Twenty-Five Years of Empirical Studies

ERIC Educational Resources Information Center

Lundahl, Brad W.; Kunz, Chelsea; Brownell, Cynthia; Tollefson, Derrik; Burke, Brian L.

2010-01-01

Objective: The authors investigated the unique contribution motivational interviewing (MI) has on counseling outcomes and how MI compares with other interventions. Method: A total of 119 studies were subjected to a meta-analysis. Targeted outcomes included substance use (tobacco, alcohol, drugs, marijuana), health-related behaviors (diet,…

Evolving Approaches to the Study of Childhood Poverty and Education

ERIC Educational Resources Information Center

Hannum, Emily; Liu, Ran; Alvarado-Urbina, Andrea

2017-01-01

Social scientists have conceptualised poverty in multiple ways, with measurement approaches that seek to identify absolute, relative, subjective, and multi-dimensional poverty. The concept of poverty is central in the comparative education field, but has been empirically elusive in many large, international educational surveys: these studies have…

Comparison of Stepped Care Delivery Against a Single, Empirically Validated Cognitive-Behavioral Therapy Program for Youth With Anxiety: A Randomized Clinical Trial.

PubMed

Rapee, Ronald M; Lyneham, Heidi J; Wuthrich, Viviana; Chatterton, Mary Lou; Hudson, Jennifer L; Kangas, Maria; Mihalopoulos, Cathrine

2017-10-01

Stepped care is embraced as an ideal model of service delivery but is minimally evaluated. The aim of this study was to evaluate the efficacy of cognitive-behavioral therapy (CBT) for child anxiety delivered via a stepped-care framework compared against a single, empirically validated program. A total of 281 youth with anxiety disorders (6-17 years of age) were randomly allocated to receive either empirically validated treatment or stepped care involving the following: (1) low intensity; (2) standard CBT; and (3) individually tailored treatment. Therapist qualifications increased at each step. Interventions did not differ significantly on any outcome measures. Total therapist time per child was significantly shorter to deliver stepped care (774 minutes) compared with best practice (897 minutes). Within stepped care, the first 2 steps returned the strongest treatment gains. Stepped care and a single empirically validated program for youth with anxiety produced similar efficacy, but stepped care required slightly less therapist time. Restricting stepped care to only steps 1 and 2 would have led to considerable time saving with modest loss in efficacy. Clinical trial registration information-A Randomised Controlled Trial of Standard Care Versus Stepped Care for Children and Adolescents With Anxiety Disorders; http://anzctr.org.au/; ACTRN12612000351819. Copyright © 2017 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.

Ab Initio and Improved Empirical Potentials for the Calculation of the Anharmonic Vibrational States and Intramolecular Mode Coupling of N-Methylacetamide

NASA Technical Reports Server (NTRS)

Gregurick, Susan K.; Chaban, Galina M.; Gerber, R. Benny; Kwak, Dochou (Technical Monitor)

2001-01-01

The second-order Moller-Plesset ab initio electronic structure method is used to compute points for the anharmonic mode-coupled potential energy surface of N-methylacetamide (NMA) in the trans(sub ct) configuration, including all degrees of freedom. The vibrational states and the spectroscopy are directly computed from this potential surface using the Correlation Corrected Vibrational Self-Consistent Field (CC-VSCF) method. The results are compared with CC-VSCF calculations using both the standard and improved empirical Amber-like force fields and available low temperature experimental matrix data. Analysis of our calculated spectroscopic results show that: (1) The excellent agreement between the ab initio CC-VSCF calculated frequencies and the experimental data suggest that the computed anharmonic potentials for N-methylacetamide are of a very high quality; (2) For most transitions, the vibrational frequencies obtained from the ab initio CC-VSCF method are superior to those obtained using the empirical CC-VSCF methods, when compared with experimental data. However, the improved empirical force field yields better agreement with the experimental frequencies as compared with a standard AMBER-type force field; (3) The empirical force field in particular overestimates anharmonic couplings for the amide-2 mode, the methyl asymmetric bending modes, the out-of-plane methyl bending modes, and the methyl distortions; (4) Disagreement between the ab initio and empirical anharmonic couplings is greater than the disagreement between the frequencies, and thus the anharmonic part of the empirical potential seems to be less accurate than the harmonic contribution;and (5) Both the empirical and ab initio CC-VSCF calculations predict a negligible anharmonic coupling between the amide-1 and other internal modes. The implication of this is that the intramolecular energy flow between the amide-1 and the other internal modes may be smaller than anticipated. These results may have important implications for the anharmonic force fields of peptides, for which N-methylacetamide is a model.

Cooperative Factors, Cooperative Innovation Effect and Innovation Performance for Chinese Firms: an Empirical Study

NASA Astrophysics Data System (ADS)

Xie, Xuemei

Based on a survey to 1206 Chinese firms, this paper empirically explores the factors impacting cooperative innovation effect of firms, and seeks to explore the relationship between cooperative innovation effect (CIE) and innovation performance using the technique of Structural Equation Modeling (SEM). The study finds there are significant positive relationships between basic sustaining factors, factors of government and policy, factors of cooperation mechanism and social network, and cooperative innovation effect. However, the result reveals that factors of government and policy demonstrate little impact on the CIE of firms compared with other factors. It is hoped that the findings can pave the way for future studies in improving cooperative innovation capacity for firms in emerging countries.

An empirical analysis of the public's attitudes toward advertising hospital services: a comparative cross-sectional study.

PubMed

Moser, H Ronald; Freeman, Gordon L

2014-01-01

This study investigates current opinions about hospital advertising and compares them to the attitudes expressed 25 years ago. It replicates a survey done in 1985, using the same questionnaire and population to compare responses longitudinally. The study indicates some changes in the public's opinions of hospital advertising. Although the image of hospitals remains positive, most of the 2010 respondents' opinions were rather mixed regarding whether it is proper for hospitals to advertise. The study also confirmed that the quality of service and reputation of hospitals remain more important to the public than price.

Automation and cognition in air traffic control : an empirical investigation.

DOT National Transportation Integrated Search

1994-02-01

Several investigators have expressed concern that the imminent automation of air traffic control may have negative consequences on cognitive functioning, and ultimately on performance. We investigated these possibilities empirically by comparing norm...

Exponential model for option prices: Application to the Brazilian market

NASA Astrophysics Data System (ADS)

Ramos, Antônio M. T.; Carvalho, J. A.; Vasconcelos, G. L.

2016-03-01

In this paper we report an empirical analysis of the Ibovespa index of the São Paulo Stock Exchange and its respective option contracts. We compare the empirical data on the Ibovespa options with two option pricing models, namely the standard Black-Scholes model and an empirical model that assumes that the returns are exponentially distributed. It is found that at times near the option expiration date the exponential model performs better than the Black-Scholes model, in the sense that it fits the empirical data better than does the latter model.

Volatility in financial markets: stochastic models and empirical results

NASA Astrophysics Data System (ADS)

Miccichè, Salvatore; Bonanno, Giovanni; Lillo, Fabrizio; Mantegna, Rosario N.

2002-11-01

We investigate the historical volatility of the 100 most capitalized stocks traded in US equity markets. An empirical probability density function (pdf) of volatility is obtained and compared with the theoretical predictions of a lognormal model and of the Hull and White model. The lognormal model well describes the pdf in the region of low values of volatility whereas the Hull and White model better approximates the empirical pdf for large values of volatility. Both models fail in describing the empirical pdf over a moderately large volatility range.

The Waterfall Model in Large-Scale Development

NASA Astrophysics Data System (ADS)

Petersen, Kai; Wohlin, Claes; Baca, Dejan

Waterfall development is still a widely used way of working in software development companies. Many problems have been reported related to the model. Commonly accepted problems are for example to cope with change and that defects all too often are detected too late in the software development process. However, many of the problems mentioned in literature are based on beliefs and experiences, and not on empirical evidence. To address this research gap, we compare the problems in literature with the results of a case study at Ericsson AB in Sweden, investigating issues in the waterfall model. The case study aims at validating or contradicting the beliefs of what the problems are in waterfall development through empirical research.

Hybrid empirical mode decomposition- ARIMA for forecasting exchange rates

NASA Astrophysics Data System (ADS)

Abadan, Siti Sarah; Shabri, Ani; Ismail, Shuhaida

2015-02-01

This paper studied the forecasting of monthly Malaysian Ringgit (MYR)/ United State Dollar (USD) exchange rates using the hybrid of two methods which are the empirical model decomposition (EMD) and the autoregressive integrated moving average (ARIMA). MYR is pegged to USD during the Asian financial crisis causing the exchange rates are fixed to 3.800 from 2nd of September 1998 until 21st of July 2005. Thus, the chosen data in this paper is the post-July 2005 data, starting from August 2005 to July 2010. The comparative study using root mean square error (RMSE) and mean absolute error (MAE) showed that the EMD-ARIMA outperformed the single-ARIMA and the random walk benchmark model.

A Comparison of Full and Empirical Bayes Techniques for Inferring Sea Level Changes from Tide Gauge Records

NASA Astrophysics Data System (ADS)

Piecuch, C. G.; Huybers, P. J.; Tingley, M.

2016-12-01

Sea level observations from coastal tide gauges are some of the longest instrumental records of the ocean. However, these data can be noisy, biased, and gappy, featuring missing values, and reflecting land motion and local effects. Coping with these issues in a formal manner is a challenging task. Some studies use Bayesian approaches to estimate sea level from tide gauge records, making inference probabilistically. Such methods are typically empirically Bayesian in nature: model parameters are treated as known and assigned point values. But, in reality, parameters are not perfectly known. Empirical Bayes methods thus neglect a potentially important source of uncertainty, and so may overestimate the precision (i.e., underestimate the uncertainty) of sea level estimates. We consider whether empirical Bayes methods underestimate uncertainty in sea level from tide gauge data, comparing to a full Bayes method that treats parameters as unknowns to be solved for along with the sea level field. We develop a hierarchical algorithm that we apply to tide gauge data on the North American northeast coast over 1893-2015. The algorithm is run in full Bayes mode, solving for the sea level process and parameters, and in empirical mode, solving only for the process using fixed parameter values. Error bars on sea level from the empirical method are smaller than from the full Bayes method, and the relative discrepancies increase with time; the 95% credible interval on sea level values from the empirical Bayes method in 1910 and 2010 is 23% and 56% narrower, respectively, than from the full Bayes approach. To evaluate the representativeness of the credible intervals, empirical Bayes and full Bayes methods are applied to corrupted data of a known surrogate field. Using rank histograms to evaluate the solutions, we find that the full Bayes method produces generally reliable error bars, whereas the empirical Bayes method gives too-narrow error bars, such that the 90% credible interval only encompasses 70% of true process values. Results demonstrate that parameter uncertainty is an important source of process uncertainty, and advocate for the fully Bayesian treatment of tide gauge records in ocean circulation and climate studies.

Empirical likelihood-based confidence intervals for the sensitivity of a continuous-scale diagnostic test at a fixed level of specificity.

PubMed

Gengsheng Qin; Davis, Angela E; Jing, Bing-Yi

2011-06-01

For a continuous-scale diagnostic test, it is often of interest to find the range of the sensitivity of the test at the cut-off that yields a desired specificity. In this article, we first define a profile empirical likelihood ratio for the sensitivity of a continuous-scale diagnostic test and show that its limiting distribution is a scaled chi-square distribution. We then propose two new empirical likelihood-based confidence intervals for the sensitivity of the test at a fixed level of specificity by using the scaled chi-square distribution. Simulation studies are conducted to compare the finite sample performance of the newly proposed intervals with the existing intervals for the sensitivity in terms of coverage probability. A real example is used to illustrate the application of the recommended methods.

When Help Becomes Hindrance: Unexpected Errors of Omission and Commission in Eyewitness Memory Resulting from Change Temporal Order at Retrieval?

ERIC Educational Resources Information Center

Dando, Coral J.; Ormerod, Thomas C.; Wilcock, Rachel; Milne, Rebecca

2011-01-01

An experimental mock eyewitness study is reported that compared Free and reverse order recall of an empirically informed scripted crime event. Proponents of reverse order recall suggest it facilitates recovery of script incidental information and increases the total amount of information recalled. However, compared with free recall it was found to…

Facial Expression of Affect in Children with Cornelia de Lange Syndrome

ERIC Educational Resources Information Center

Collis, L.; Moss, J.; Jutley, J.; Cornish, K.; Oliver, C.

2008-01-01

Background: Individuals with Cornelia de Lange syndrome (CdLS) have been reported to show comparatively high levels of flat and negative affect but there have been no empirical evaluations. In this study, we use an objective measure of facial expression to compare affect in CdLS with that seen in Cri du Chat syndrome (CDC) and a group of…

Impact of rapid methicillin-resistant Staphylococcus aureus polymerase chain reaction testing on mortality and cost effectiveness in hospitalized patients with bacteraemia: a decision model.

PubMed

Brown, Jack; Paladino, Joseph A

2010-01-01

Patients hospitalized with Staphylococcus aureus bacteraemia have an unacceptably high mortality rate. Literature available to date has shown that timely selection of the most appropriate antibacterial may reduce mortality. One tool that may help with this selection is a polymerase chain reaction (PCR) assay that distinguishes methicillin (meticillin)-resistant S. aureus (MRSA) from methicillin-susceptible S. aureus (MSSA) in less than 1 hour. To date, no information is available evaluating the impact of this PCR technique on clinical or economic outcomes. To evaluate the effect of a rapid PCR assay on mortality and economics compared with traditional empiric therapy, using a literature-derived model. A literature search for peer-reviewed European (EU) and US publications regarding treatment regimens, outcomes and costs was conducted. Information detailing the rates of infection, as well as the specificity and sensitivity of a rapid PCR assay (Xpert MRSA/SA Blood Culture PCR) were obtained from the peer-reviewed literature. Sensitivity analysis varied the prevalence rate of MRSA from 5% to 80%, while threshold analysis was applied to the cost of the PCR test. Hospital and testing resource consumption were valued with direct medical costs, adjusted to year 2009 values. Adjusted life-years were determined using US and WHO life tables. The cost-effectiveness ratio was defined as the cost per life-year saved. Incremental cost-effectiveness ratios (ICERs) were calculated to determine the additional cost necessary to produce additional effectiveness. All analyses were performed using TreeAge Software (2008). The mean mortality rates were 23% for patients receiving empiric vancomycin subsequently switched to semi-synthetic penicillin (SSP) for MSSA, 36% for patients receiving empiric vancomycin treatment for MRSA, 59% for patients receiving empiric SSP subsequently switched to vancomycin for MRSA and 12% for patients receiving empiric SSP for MSSA. Furthermore, with an MRSA prevalence of 30%, the numbers of patients needed to test in order to save one life were 14 and 16 compared with empiric vancomycin and SSP, respectively. The absolute mortality difference for MRSA prevalence rates of 80% and 5% favoured the PCR testing group at 2% and 10%, respectively, compared with empiric vancomycin and 18% and 1%, respectively, compared with empiric SSP. In the EU, the cost-effectiveness ratios for empiric vancomycin- and SSP-treated patients were Euro 695 and Euro 687 per life-year saved, respectively, compared with Euro 636 per life-year saved for rapid PCR testing. In the US, the cost-effectiveness ratio was $US 898 per life-year saved for empiric vancomycin and $US 820 per life-year saved for rapid PCR testing. ICERs demonstrated dominance of the PCR test in all instances. Threshold analysis revealed that PCR testing would be less costly overall, even at greatly inflated assay prices. Rapid PCR testing for MRSA appears to have the potential to reduce mortality rates while being less costly than empiric therapy in the EU and US, across a wide range of MRSA prevalence rates and PCR test costs.

Organizational values in the provision of access to care for the uninsured

PubMed Central

Harrison, Krista Lyn; Taylor, Holly A.

2017-01-01

Background For the last 20 years, health provider organizations have made efforts to align mission, values, and everyday practices to ensure high-quality, high-value, and ethical care. However, little attention has been paid to the organizational values and practices of community-based programs that organize and facilitate access to care for uninsured populations. This study aimed to identify and describe organizational values relevant to resource allocation and policy decisions that affect the services offered to members, using the case of community access programs: county-based programs that provide access to care for the uninsured working poor. Methods Comparative and qualitative case study methodology was used, including document review, observations, and key informant interviews, at two geographically diverse programs. Results Nine values were identified as relevant to decision making: stewardship, quality care, access to care, service to others, community well-being, member independence, organizational excellence, decency, and fairness. The way these values were deployed in resource allocation decisions that affected services offered to the uninsured are illustrated in one example per site. Conclusions This study addresses the previous dearth in the literature regarding an empirical description of organizational values employed in decision making of community organizations. To assess the transferability of the values identified, we compared our empirical results to prior empirical and conceptual work in the United States and internationally and found substantial alignment. Future studies can examine whether the identified organizational values are reflective of those at other health care organizations. PMID:28781981

Simulation studies of chemical erosion on carbon based materials at elevated temperatures

NASA Astrophysics Data System (ADS)

Kenmotsu, T.; Kawamura, T.; Li, Zhijie; Ono, T.; Yamamura, Y.

1999-06-01

We simulated the fluence dependence of methane reaction yield in carbon with hydrogen bombardment using the ACAT-DIFFUSE code. The ACAT-DIFFUSE code is a simulation code based on a Monte Carlo method with a binary collision approximation and on solving diffusion equations. The chemical reaction model in carbon was studied by Roth or other researchers. Roth's model is suitable for the steady state methane reaction. But this model cannot estimate the fluence dependence of the methane reaction. Then, we derived an empirical formula based on Roth's model for methane reaction. In this empirical formula, we assumed the reaction region where chemical sputtering due to methane formation takes place. The reaction region corresponds to the peak range of incident hydrogen distribution in the target material. We adopted this empirical formula to the ACAT-DIFFUSE code. The simulation results indicate the similar fluence dependence compared with the experiment result. But, the fluence to achieve the steady state are different between experiment and simulation results.

Coupling of ab initio density functional theory and molecular dynamics for the multiscale modeling of carbon nanotubes

NASA Astrophysics Data System (ADS)

Ng, T. Y.; Yeak, S. H.; Liew, K. M.

2008-02-01

A multiscale technique is developed that couples empirical molecular dynamics (MD) and ab initio density functional theory (DFT). An overlap handshaking region between the empirical MD and ab initio DFT regions is formulated and the interaction forces between the carbon atoms are calculated based on the second-generation reactive empirical bond order potential, the long-range Lennard-Jones potential as well as the quantum-mechanical DFT derived forces. A density of point algorithm is also developed to track all interatomic distances in the system, and to activate and establish the DFT and handshaking regions. Through parallel computing, this multiscale method is used here to study the dynamic behavior of single-walled carbon nanotubes (SWCNTs) under asymmetrical axial compression. The detection of sideways buckling due to the asymmetrical axial compression is reported and discussed. It is noted from this study on SWCNTs that the MD results may be stiffer compared to those with electron density considerations, i.e. first-principle ab initio methods.

Distribution of the two-sample t-test statistic following blinded sample size re-estimation.

PubMed

Lu, Kaifeng

2016-05-01

We consider the blinded sample size re-estimation based on the simple one-sample variance estimator at an interim analysis. We characterize the exact distribution of the standard two-sample t-test statistic at the final analysis. We describe a simulation algorithm for the evaluation of the probability of rejecting the null hypothesis at given treatment effect. We compare the blinded sample size re-estimation method with two unblinded methods with respect to the empirical type I error, the empirical power, and the empirical distribution of the standard deviation estimator and final sample size. We characterize the type I error inflation across the range of standardized non-inferiority margin for non-inferiority trials, and derive the adjusted significance level to ensure type I error control for given sample size of the internal pilot study. We show that the adjusted significance level increases as the sample size of the internal pilot study increases. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Re-evaluating the link between brain size and behavioural ecology in primates.

PubMed

Powell, Lauren E; Isler, Karin; Barton, Robert A

2017-10-25

Comparative studies have identified a wide range of behavioural and ecological correlates of relative brain size, with results differing between taxonomic groups, and even within them. In primates for example, recent studies contradict one another over whether social or ecological factors are critical. A basic assumption of such studies is that with sufficiently large samples and appropriate analysis, robust correlations indicative of selection pressures on cognition will emerge. We carried out a comprehensive re-examination of correlates of primate brain size using two large comparative datasets and phylogenetic comparative methods. We found evidence in both datasets for associations between brain size and ecological variables (home range size, diet and activity period), but little evidence for an effect of social group size, a correlation which has previously formed the empirical basis of the Social Brain Hypothesis. However, reflecting divergent results in the literature, our results exhibited instability across datasets, even when they were matched for species composition and predictor variables. We identify several potential empirical and theoretical difficulties underlying this instability and suggest that these issues raise doubts about inferring cognitive selection pressures from behavioural correlates of brain size. © 2017 The Author(s).

Expectations versus Reality: The Case of Liberal Studies in Hong Kong's New Senior Secondary Reforms

ERIC Educational Resources Information Center

Fung, Dennis

2016-01-01

This article reports the findings of a five-year longitudinal study investigating the introduction of Liberal Studies in the context of Hong Kong's new senior secondary educational reforms. The aim of this empirical research, which adopted diachronic analysis to allow comparisons over time, was to compare teachers' and students' perceptions of the…

Using Popular Culture to Teach the Community College Business Curriculum: A Comparative Study

ERIC Educational Resources Information Center

Passero, Thomas

2011-01-01

This study addressed a need for comprehensive quantitative empirical studies to determine the effectiveness of using popular culture media as a teaching technique. A quasi-experimental design was implemented to examine whether a group of community college students taking a first-semester introduction to business course who were exposed to a…

Teachers' Perceptions of Education for Democratic Citizenship in Schools with Transnational Youth: A Comparative Study in the UK and Denmark

ERIC Educational Resources Information Center

Hahn, Carole L.

2015-01-01

As a consequence of globalization and increased immigration, scholars call for reconceptualizations of citizenship and empirical studies to ascertain how citizenship education is enacted in schools serving youth from immigration backgrounds. This study addresses these needs by interviewing civic educators in purposefully selected secondary schools…

Community-acquired enterococcal urinary tract infections in hospitalized children.

PubMed

Marcus, Nir; Ashkenazi, Shai; Samra, Zmira; Cohen, Avner; Livni, Gilat

2012-01-01

The objectives of this study were to characterize community-acquired (CA) enterococcal urinary tract infections (UTIs) in a tertiary pediatric center and to determine risk factors for their occurrence, their association with renal abnormalities, their antibiotic susceptibility profile, and the appropriateness of the empiric antibiotic treatment, in comparison to those of Gram-negative UTIs. In a 5-year prospective clinical and laboratory study, we found that enterococcal UTIs caused 6.2% (22/355) of culture-proven CA UTIs. Compared with Gram-negative UTI, enterococcal UTI was associated with male predominance, higher rates of underlying urinary abnormalities (70 vs. 43.7%; p = 0.03) and inappropriate empiric antibiotic therapy (22 vs. 5.6%; p = 0.02), and mainly vesicoureteral reflux (53% of cases). This study highlights the importance of early detection of CA enterococcal UTIs because of their association with underlying urinary abnormalities and a high rate of inappropriate empiric antibiotic therapy. Renal imaging is recommended for children with enterococcal UTIs; Gram stain is suggested in selected cases to detect Gram-positive cocci for early diagnosis of enterococcal UTIs and initiation of appropriate antibiotics.

Reliability and convergence of three concepts of narcissistic personality.

PubMed

Perry, J D; Perry, J C

1996-01-01

UNTIL recent years, the personality disorders have been relatively unexplored compared to other psychiatric diagnoses. Over 15 years ago, there was little agreement on the diagnosis of borderline personality disorder (Perry and Klerman 1978), but efforts to specify the constructs and respective criteria for the borderline diagnosis spurred a plethora of systematic research. The result is that, next to antisocial personality disorder, borderline has become one of the best-documented and validated personality disorders (Perry and Vaillant 1989). One important shift has been that good descriptive studies have gradually led to studies of etiological factors, such as childhood physical and sexual abuse, and severe neglect (Herman et al. 1989; Perry and Herman 1992), which in turn have led to empirically based treatment approaches (Herman 1992; Perry et al. 1990). Despite inclusion in The Diagnostic and Statistical Manual of Mental Disorders (DSM-III and DSM-III-R), narcissistic personality is still at the beginning of this process of description, empirical testing, and validation (Gunderson et al. 1991). This study empirically examines three descriptions of narcissistic personality in order to look for common underlying dimensions that may have etiological and treatment significance.

The Contingent Valuation Method in Public Libraries

ERIC Educational Resources Information Center

Chung, Hye-Kyung

2008-01-01

This study aims to present a new model measuring the economic value of public libraries, combining the dissonance minimizing (DM) and information bias minimizing (IBM) format in the contingent valuation (CV) surveys. The possible biases which are tied to the conventional CV surveys are reviewed. An empirical study is presented to compare the model…

Meaningful Commitment: Finding Meaning in Volunteer Work

ERIC Educational Resources Information Center

Schnell, Tatjana; Hoof, Matthias

2012-01-01

This study tests the hypothesis that volunteer work is associated with various aspects of meaning making by employing a multi-dimensional model of meaning operationalized by the "Sources of Meaning and Meaning in Life Questionnaire" ("SoMe"). An empirical study comparing 168 volunteers with a representative sample of the general population (N =…

Who Are We Studying? Sample Diversity in Teaching of Psychology Research

ERIC Educational Resources Information Center

Richmond, Aaron S.; Broussard, Kristin A.; Sterns, Jillian L.; Sanders, Kristina K.; Shardy, Justin C.

2015-01-01

The purpose of the current study was to examine the sample diversity of empirical articles published in four premier teaching of psychology journals from 2008 to 2013. We investigated which demographic information was commonly reported and if samples were ethnically representative and whether gender was representative compared to National…

More than Just Chemistry: The Impact of a Collaborative Participant Structure on Student Perceptions of Science

ERIC Educational Resources Information Center

Patchen, Terri; Smithenry, Dennis W.

2015-01-01

Researchers have theorized that integrating authentic science activities into classrooms will help students learn how working scientists collaboratively construct knowledge, but few empirical studies have examined students' experiences with these types of activities. Utilizing data from a comparative, mixed-methods study, we considered how…

Generic Behavioural Criteria of Managerial Effectiveness: An Empirical and Comparative Case Study of UK Local Government

ERIC Educational Resources Information Center

Hamlin, Robert G.; Serventi, Susan A.

2008-01-01

Purpose: The purpose of this paper is to present the findings of a "partnership-research" study of effective and ineffective managerial behaviour within the "local government" setting of the Wolverhampton City Council Social Care Department, and to describe how the research supports and challenges the organisation's existing…

Improving Performance for Gifted Students in a Cluster Grouping Model

ERIC Educational Resources Information Center

Brulles, Dina; Saunders, Rachel; Cohn, Sanford J.

2010-01-01

Although experts in gifted education widely promote cluster grouping gifted students, little empirical evidence is available to attest to its effectiveness. This study is an example of comparative action research in the form of a quantitative case study that focused on the mandated cluster grouping practices for gifted students in an urban…

The Consequences of Fading Instructional Guidance on Delayed Performance: The Case of Financial Services Training

ERIC Educational Resources Information Center

Kissane, Mark; Kalyuga, Slava; Chandler, Paul; Sweller, John

2008-01-01

Empirical studies within a cognitive load framework have determined that for novice learners, worked examples provide appropriate levels of instructional guidance. As learners advance in specific subject domains, worked examples should be gradually replaced by practice problems with limited guidance. This study compared performance, both…

A Meta-Analysis of Effectiveness Studies on Computer Technology-Supported Language Learning

ERIC Educational Resources Information Center

Grgurovic, Maja; Chapelle, Carol A.; Shelley, Mack C.

2013-01-01

With the aim of summarizing years of research comparing pedagogies for second/foreign language teaching supported with computer technology and pedagogy not-supported by computer technology, a meta-analysis was conducted of empirical research investigating language outcomes. Thirty-seven studies yielding 52 effect sizes were included, following a…

The Impact of Creative Learning Environments on Learners: A Systematic Literature Review

ERIC Educational Resources Information Center

Jindal-Snape, Divya; Davies, Dan; Collier, Chris; Howe, Alan; Digby, Rebecca; Hay, Penny

2013-01-01

This article is based on a systematic review of educational research, policy and professional literature relating to creative environments for learning in schools. Despite the search yielding 210 documents, comparatively few empirical studies were published between 2005 and 2011 that addressed the review objectives. Only 18 studies included in the…

The Empirical Review of Meta-Analysis Published in Korea

ERIC Educational Resources Information Center

Park, Sunyoung; Hong, Sehee

2016-01-01

Meta-analysis is a statistical method that is increasingly utilized to combine and compare the results of previous primary studies. However, because of the lack of comprehensive guidelines for how to use meta-analysis, many meta-analysis studies have failed to consider important aspects, such as statistical programs, power analysis, publication…

Student Interests--The German and Austrian ROSE Survey

ERIC Educational Resources Information Center

Elster, Doris

2007-01-01

ROSE (the Relevance of Science Education) is an international comparative study on the factors which influence learning in science. For this study, the interests, opinions and attitudes of young people were polled by using a standardised questionnaire. Initial data, empirically gathered from 1247 students at the end of lower secondary level in…

Prevalence of Mindfulness Literature and Intervention in School Psychology Journals from 2006 to 2016

ERIC Educational Resources Information Center

Bender, Stacy L.; Roth, Rachel; Zielenski, Alicia; Longo, Zachary; Chermak, Ashley

2018-01-01

Mindfulness has been gaining momentum in the field of school psychology, however compared to other applied psychology fields, less research on mindfulness interventions has been conducted. This study systematically reviewed mindfulness literature and empirical studies in nine school psychology journals from 2006-2016. The prevalence of mindfulness…

A Comparison of Community College Full-Time and Adjunct Faculties' Perceptions of Factors Associated with Grade Inflation

ERIC Educational Resources Information Center

Schutz, Kelly R.; Drake, Brent M.; Lessner, Janet; Hughes, Gail F.

2015-01-01

Grades historically have indicated student performance in college. Previous studies in the higher education literature, primarily conducted at four-year teaching institutions, have suggested reasons for grade inflation but have provided little supporting empirical data. This quantitative, non-experimental, comparative study used survey research to…

Institutions and national development in Latin America: a comparative study

PubMed Central

Portes, Alejandro; Smith, Lori D.

2013-01-01

We review the theoretical and empirical literatures on the role of institutions on national development as a prelude to present a more rigorous and measurable definition of the concept and a methodology to study this relationship at the national and subnational levels. The existing research literature features conflicting definitions of the concept of “institutions” and empirical tests based mostly on reputational indices, with countries as units of analysis. The present study’s methodology is based on a set of five strategic organizations studied comparatively in five Latin American countries. These include key federal agencies, public administrative organizations, and stock exchanges. Systematic analysis of results show a pattern of differences between economically-oriented institutions and those entrusted with providing basic services to the general population. Consistent differences in institutional quality also emerge across countries, despite similar levels of economic development. Using the algebraic methods developed by Ragin, we test six hypotheses about factors determining the developmental character of particular institutions. Implications of results for theory and for methodological practices of future studies in this field are discussed. PMID:26543407

The ecological module of BOATS-1.0: a bioenergetically-constrained model of marine upper trophic levels suitable for studies of fisheries and ocean biogeochemistry

NASA Astrophysics Data System (ADS)

Carozza, D. A.; Bianchi, D.; Galbraith, E. D.

2015-12-01

Environmental change and the exploitation of marine resources have had profound impacts on marine communities, with potential implications for ocean biogeochemistry and food security. In order to study such global-scale problems, it is helpful to have computationally efficient numerical models that predict the first-order features of fish biomass production as a function of the environment, based on empirical and mechanistic understandings of marine ecosystems. Here we describe the ecological module of the BiOeconomic mArine Trophic Size-spectrum (BOATS) model, which takes an Earth-system approach to modeling fish biomass at the global scale. The ecological model is designed to be used on an Earth System model grid, and determines size spectra of fish biomass by explicitly resolving life history as a function of local temperature and net primary production. Biomass production is limited by the availability of photosynthetic energy to upper trophic levels, following empirical trophic efficiency scalings, and by well-established empirical temperature-dependent growth rates. Natural mortality is calculated using an empirical size-based relationship, while reproduction and recruitment depend on both the food availability to larvae from net primary production and the production of eggs by mature adult fish. We describe predicted biomass spectra and compare them to observations, and conduct a sensitivity study to determine how the change as a function of net primary production and temperature. The model relies on a limited number of parameters compared to similar modeling efforts, while retaining realistic representations of biological and ecological processes, and is computationally efficient, allowing extensive parameter-space analyses even when implemented globally. As such, it enables the exploration of the linkages between ocean biogeochemistry, climate, and upper trophic levels at the global scale, as well as a representation of fish biomass for idealized studies of fisheries.

The ecological module of BOATS-1.0: a bioenergetically constrained model of marine upper trophic levels suitable for studies of fisheries and ocean biogeochemistry

NASA Astrophysics Data System (ADS)

Carozza, David Anthony; Bianchi, Daniele; Galbraith, Eric Douglas

2016-04-01

Environmental change and the exploitation of marine resources have had profound impacts on marine communities, with potential implications for ocean biogeochemistry and food security. In order to study such global-scale problems, it is helpful to have computationally efficient numerical models that predict the first-order features of fish biomass production as a function of the environment, based on empirical and mechanistic understandings of marine ecosystems. Here we describe the ecological module of the BiOeconomic mArine Trophic Size-spectrum (BOATS) model, which takes an Earth-system approach to modelling fish biomass at the global scale. The ecological model is designed to be used on an Earth-system model grid, and determines size spectra of fish biomass by explicitly resolving life history as a function of local temperature and net primary production. Biomass production is limited by the availability of photosynthetic energy to upper trophic levels, following empirical trophic efficiency scalings, and by well-established empirical temperature-dependent growth rates. Natural mortality is calculated using an empirical size-based relationship, while reproduction and recruitment depend on both the food availability to larvae from net primary production and the production of eggs by mature adult fish. We describe predicted biomass spectra and compare them to observations, and conduct a sensitivity study to determine how they change as a function of net primary production and temperature. The model relies on a limited number of parameters compared to similar modelling efforts, while retaining reasonably realistic representations of biological and ecological processes, and is computationally efficient, allowing extensive parameter-space analyses even when implemented globally. As such, it enables the exploration of the linkages between ocean biogeochemistry, climate, and upper trophic levels at the global scale, as well as a representation of fish biomass for idealized studies of fisheries.

College Students' Goals, Plans, and Background Characteristics; A Synthesis of Three Empirical Studies.

ERIC Educational Resources Information Center

Fenske, Robert H.; Scott, Craig S.

This study was designed to provide longitudinal data bearing on the change and/or stability of college-bound students' educational and vocational goals, as well as their background characteristics. Data from three studies were contrasted and compared. Included in these studies were: (1) a 2-year followup of 4,009 junior college students; (2) a…

An Empirical Study of the Distributional Changes in Higher Education among East, Middle and West China

ERIC Educational Resources Information Center

Jiang, Chunjiao; Li, Song

2008-01-01

Based on the quantitative research and comparative study method, this paper attempts to make a systematic study and analysis of regional differences which have existed since 1949 in higher education among East, Middle and West China. The study is intended to explore the causes, regional differences, social changes, and their co-related…

Issues in benchmarking human reliability analysis methods : a literature review.

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

Lois, Erasmia; Forester, John Alan; Tran, Tuan Q.

There is a diversity of human reliability analysis (HRA) methods available for use in assessing human performance within probabilistic risk assessment (PRA). Due to the significant differences in the methods, including the scope, approach, and underlying models, there is a need for an empirical comparison investigating the validity and reliability of the methods. To accomplish this empirical comparison, a benchmarking study is currently underway that compares HRA methods with each other and against operator performance in simulator studies. In order to account for as many effects as possible in the construction of this benchmarking study, a literature review was conducted,more » reviewing past benchmarking studies in the areas of psychology and risk assessment. A number of lessons learned through these studies are presented in order to aid in the design of future HRA benchmarking endeavors.« less

An Empirical Study of Atmospheric Correction Procedures for Regional Infrasound Amplitudes with Ground Truth.

NASA Astrophysics Data System (ADS)

Howard, J. E.

2014-12-01

This study focusses on improving methods of accounting for atmospheric effects on infrasound amplitudes observed on arrays at regional distances in the southwestern United States. Recordings at ranges of 150 to nearly 300 km from a repeating ground truth source of small HE explosions are used. The explosions range in actual weight from approximately 2000-4000 lbs. and are detonated year-round which provides signals for a wide range of atmospheric conditions. Three methods of correcting the observed amplitudes for atmospheric effects are investigated with the data set. The first corrects amplitudes for upper stratospheric wind as developed by Mutschlecner and Whitaker (1999) and uses the average wind speed between 45-55 km altitudes in the direction of propagation to derive an empirical correction formula. This approach was developed using large chemical and nuclear explosions and is tested with the smaller explosions for which shorter wavelengths cause the energy to be scattered by the smaller scale structure of the atmosphere. The second approach isa semi-empirical method using ray tracing to determine wind speed at ray turning heights where the wind estimates replace the wind values in the existing formula. Finally, parabolic equation (PE) modeling is used to predict the amplitudes at the arrays at 1 Hz. The PE amplitudes are compared to the observed amplitudes with a narrow band filter centered at 1 Hz. An analysis is performed of the conditions under which the empirical and semi-empirical methods fail and full wave methods must be used.

An empirical model of human aspiration in low-velocity air using CFD investigations.

PubMed

Anthony, T Renée; Anderson, Kimberly R

2015-01-01

Computational fluid dynamics (CFD) modeling was performed to investigate the aspiration efficiency of the human head in low velocities to examine whether the current inhaled particulate mass (IPM) sampling criterion matches the aspiration efficiency of an inhaling human in airflows common to worker exposures. Data from both mouth and nose inhalation, averaged to assess omnidirectional aspiration efficiencies, were compiled and used to generate a unifying model to relate particle size to aspiration efficiency of the human head. Multiple linear regression was used to generate an empirical model to estimate human aspiration efficiency and included particle size as well as breathing and freestream velocities as dependent variables. A new set of simulated mouth and nose breathing aspiration efficiencies was generated and used to test the fit of empirical models. Further, empirical relationships between test conditions and CFD estimates of aspiration were compared to experimental data from mannequin studies, including both calm-air and ultra-low velocity experiments. While a linear relationship between particle size and aspiration is reported in calm air studies, the CFD simulations identified a more reasonable fit using the square of particle aerodynamic diameter, which better addressed the shape of the efficiency curve's decline toward zero for large particles. The ultimate goal of this work was to develop an empirical model that incorporates real-world variations in critical factors associated with particle aspiration to inform low-velocity modifications to the inhalable particle sampling criterion.

Developing comparative criminology and the case of China: an introduction.

PubMed

Liu, Jianhong

2007-02-01

Although comparative criminology has made significant development during the past decade or so, systematic empirical research has only developed along a few topics. Comparative criminology has never occupied a central position in criminology. This article analyzes the major theoretical and methodological impediments in the development of comparative criminology. It stresses a need to shift methodology from a conventional primary approach that uses the nation as the unit of analysis to an in-depth case study method as a primary methodological approach. The article maintains that case study method can overcome the limitation of its descriptive tradition and become a promising methodological approach for comparative criminology.

Tracer kinetics of forearm endothelial function: comparison of an empirical method and a quantitative modeling technique.

PubMed

Zhao, Xueli; Arsenault, Andre; Lavoie, Kim L; Meloche, Bernard; Bacon, Simon L

2007-01-01

Forearm Endothelial Function (FEF) is a marker that has been shown to discriminate patients with cardiovascular disease (CVD). FEF has been assessed using several parameters: the Rate of Uptake Ratio (RUR), EWUR (Elbow-to-Wrist Uptake Ratio) and EWRUR (Elbow-to-Wrist Relative Uptake Ratio). However, the modeling functions of FEF require more robust models. The present study was designed to compare an empirical method with quantitative modeling techniques to better estimate the physiological parameters and understand the complex dynamic processes. The fitted time activity curves of the forearms, estimating blood and muscle components, were assessed using both an empirical method and a two-compartment model. Although correlational analyses suggested a good correlation between the methods for RUR (r=.90) and EWUR (r=.79), but not EWRUR (r=.34), Altman-Bland plots found poor agreement between the methods for all 3 parameters. These results indicate that there is a large discrepancy between the empirical and computational method for FEF. Further work is needed to establish the physiological and mathematical validity of the 2 modeling methods.

On the predictability of land surface fluxes from meteorological variables

NASA Astrophysics Data System (ADS)

Haughton, Ned; Abramowitz, Gab; Pitman, Andy J.

2018-01-01

Previous research has shown that land surface models (LSMs) are performing poorly when compared with relatively simple empirical models over a wide range of metrics and environments. Atmospheric driving data appear to provide information about land surface fluxes that LSMs are not fully utilising. Here, we further quantify the information available in the meteorological forcing data that are used by LSMs for predicting land surface fluxes, by interrogating FLUXNET data, and extending the benchmarking methodology used in previous experiments. We show that substantial performance improvement is possible for empirical models using meteorological data alone, with no explicit vegetation or soil properties, thus setting lower bounds on a priori expectations on LSM performance. The process also identifies key meteorological variables that provide predictive power. We provide an ensemble of empirical benchmarks that are simple to reproduce and provide a range of behaviours and predictive performance, acting as a baseline benchmark set for future studies. We reanalyse previously published LSM simulations and show that there is more diversity between LSMs than previously indicated, although it remains unclear why LSMs are broadly performing so much worse than simple empirical models.

Study Abroad and Interlanguage Pragmatic Development in Request and Apology Speech Acts among Iranian Learners

ERIC Educational Resources Information Center

Khorshidi, Hassan Rasouli

2013-01-01

This research study empirically investigated the impact of study abroad context on L2 learners' pragmatic development compared with study at home group in Iran. For the study abroad group the participants were selected from the Iranian students who registered in a six-month program in language institutes in India (Mysore) and for the study at home…

[Systematic review and evidence mapping of empirical studies on health status and medical care among refugees and asylum seekers in Germany (1990-2014)].

PubMed

Bozorgmehr, Kayvan; Mohsenpour, Amir; Saure, Daniel; Stock, Christian; Loerbroks, Adrian; Joos, Stefanie; Schneider, Christine

2016-05-01

Owing to a lack of routine statistics on the health status and medical care of asylum seekers, empirical studies play a major role in the mapping of these aspects. The aim of this review is to provide a comprehensive overview of the research landscape in this area, synthesizing knowledge from empirical studies and identifying evidence gaps. A three-tiered search strategy included searching for empirical studies in national/international databases and on the internet, screening reference lists, and contacting experts. Studies meeting predefined inclusion criteria were thematically organized and described in a narrative synthesis. The searches generated 1,190 hits; 52 articles met the inclusion criteria. Of these, 41 were quantitative studies (78.9 %), 10 qualitative (19.2 %), and 1 was a review (1.9 %). A total of 30 primary articles (58.9 %) analyzed mental health aspects, followed by infectious diseases (n = 12, 23.5 %). Qualitative studies, mainly ethnographies and case studies, explored mental health and social determinants of health, providing evidence for the impact of living conditions on health and medical care. Few studies analyzed chronic diseases (n = 3) or childhood illnesses (n = 6). No studies analyzed the health needs or medical care of asylum-seeking women during pregnancy and child birth. In 62.7 % of the primary studies, a single sampling point was used to recruit asylum seekers. Nationwide external validity was given in two quantitative studies. The priority research areas identified are chronic diseases and childhood and maternal health. The divergency and heterogeneity of the studies hamper a comprehensive and comparable acquisition of knowledgeand emphasize the  need for collaborative research to close the existing evidence gaps.

Meta-analysis of haplotype-association studies: comparison of methods and empirical evaluation of the literature

PubMed Central

2011-01-01

Background Meta-analysis is a popular methodology in several fields of medical research, including genetic association studies. However, the methods used for meta-analysis of association studies that report haplotypes have not been studied in detail. In this work, methods for performing meta-analysis of haplotype association studies are summarized, compared and presented in a unified framework along with an empirical evaluation of the literature. Results We present multivariate methods that use summary-based data as well as methods that use binary and count data in a generalized linear mixed model framework (logistic regression, multinomial regression and Poisson regression). The methods presented here avoid the inflation of the type I error rate that could be the result of the traditional approach of comparing a haplotype against the remaining ones, whereas, they can be fitted using standard software. Moreover, formal global tests are presented for assessing the statistical significance of the overall association. Although the methods presented here assume that the haplotypes are directly observed, they can be easily extended to allow for such an uncertainty by weighting the haplotypes by their probability. Conclusions An empirical evaluation of the published literature and a comparison against the meta-analyses that use single nucleotide polymorphisms, suggests that the studies reporting meta-analysis of haplotypes contain approximately half of the included studies and produce significant results twice more often. We show that this excess of statistically significant results, stems from the sub-optimal method of analysis used and, in approximately half of the cases, the statistical significance is refuted if the data are properly re-analyzed. Illustrative examples of code are given in Stata and it is anticipated that the methods developed in this work will be widely applied in the meta-analysis of haplotype association studies. PMID:21247440

Cost-effectiveness of ceftolozane/tazobactam compared with piperacillin/tazobactam as empiric therapy based on the in-vitro surveillance of bacterial isolates in the United States for the treatment of complicated urinary tract infections.

PubMed

Kauf, Teresa L; Prabhu, Vimalanand S; Medic, Goran; Borse, Rebekah H; Miller, Benjamin; Gaultney, Jennifer; Sen, Shuvayu S; Basu, Anirban

2017-04-28

A challenge in the empiric treatment of complicated urinary tract infection (cUTI) is identifying the initial appropriate antibiotic therapy (IAAT), which is associated with reduced length of stay and mortality compared with initial inappropriate antibiotic therapy (IIAT). We evaluated the cost-effectiveness of ceftolozane/tazobactam compared with piperacillin/tazobactam (one of the standard of care antibiotics), for the treatment of hospitalized patients with cUTI. A decision-analytic Monte Carlo simulation model was developed to compare the costs and effectiveness of empiric treatment with either ceftolozane/tazobactam or piperacillin/tazobactam in hospitalized adult patients with cUTI infected with Gram-negative pathogens in the US. The model applies the baseline prevalence of resistance as reported by national in-vitro surveillance data. In a cohort of 1000 patients, treatment with ceftolozane/tazobactam resulted in higher total costs compared with piperacillin/tazobactam ($36,413 /patient vs. $36,028/patient, respectively), greater quality-adjusted life years (QALYs) (9.19/patient vs. 9.13/patient, respectively) and an incremental cost-effectiveness ratio (ICER) of $6128/QALY. Ceftolozane/tazobactam remained cost-effective at a willingness to pay of $100,000 per QALY compared to piperacillin/tazobactam over a range of input parameter values during one-way and probabilistic sensitivity analysis. Model results show that ceftolozane/tazobactam is likely to be cost-effective compared with piperacillin/tazobactam for the empiric treatment of hospitalized cUTI patients in the United States.

Antibiotic Therapy for Very Low Birth Weigh Newborns in NICU

PubMed Central

Afjeh, Seyyed-Abolfazl; Sabzehei, Mohammad-Kazem; Fahimzad, Seyyed-Ali-Reza; Shiva, Farideh; Shamshiri, Ahmad-Reza; Esmaili, Fatemeh

2016-01-01

Background Prolonged empiric antibiotics therapy in neonates results in several adverse consequences including widespread antibiotic resistance, late onset sepsis (LOS), necrotizing enterocolitis (NEC), prolonged hospital course (HC) and increase in mortality rates. Objectives To assess the risk factors and the outcome of prolonged empiric antibiotic therapy in very low birth weight (VLBW) newborns. Materials and Methods Prospective study in VLBW neonates admitted to NICU and survived > 2 W, from July 2011 - June 2012. All relevant perinatal and postnatal data including duration of antibiotics therapy (Group I < 2W vs Group II > 2W) and outcome up to the time of discharge or death were documented and compared. Results Out of 145 newborns included in the study, 62 were in group I, and 83 in Group II. Average duration of antibiotic therapy was 14 days (range 3 - 62 days); duration in Group I and Group II was 10 ± 2.3 vs 25.5 ± 10.5 days. Hospital stay was 22.3 ± 11.5 vs 44.3 ± 14.7 days, respectively. Multiple regression analysis revealed following risk factors as significant for prolonged empiric antibiotic therapy: VLBW especially < 1000 g, (P < 0.001), maternal Illness (P = 0.003), chorioamnionitis (P = 0.048), multiple pregnancy (P = 0.03), non-invasive ventilation (P < 0.001) and mechanical ventilation (P < 0.001). Seventy (48.3%) infants developed LOS; 5 with NEC > stage II, 12 (8.3%) newborns died. Infant mortality alone and with LOS/NEC was higher in group II as compared to group I (P < 0.002 and < 0.001 respectively). Conclusions Prolonged empiric antibiotic therapy caused increasing rates of LOS, NEC, HC and infant mortality. PMID:27307961

Modeling of ESD events from polymeric surfaces

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

Pfeifer, Kent Bryant

2014-03-01

Transient electrostatic discharge (ESD) events are studied to assemble a predictive model of discharge from polymer surfaces. An analog circuit simulation is produced and its response is compared to various literature sources to explore its capabilities and limitations. Results suggest that polymer ESD events can be predicted to within an order of magnitude. These results compare well to empirical findings from other sources having similar reproducibility.

Sensitivity of ab Initio vs Empirical Methods in Computing Structural Effects on NMR Chemical Shifts for the Example of Peptides.

PubMed

Sumowski, Chris Vanessa; Hanni, Matti; Schweizer, Sabine; Ochsenfeld, Christian

2014-01-14

The structural sensitivity of NMR chemical shifts as computed by quantum chemical methods is compared to a variety of empirical approaches for the example of a prototypical peptide, the 38-residue kaliotoxin KTX comprising 573 atoms. Despite the simplicity of empirical chemical shift prediction programs, the agreement with experimental results is rather good, underlining their usefulness. However, we show in our present work that they are highly insensitive to structural changes, which renders their use for validating predicted structures questionable. In contrast, quantum chemical methods show the expected high sensitivity to structural and electronic changes. This appears to be independent of the quantum chemical approach or the inclusion of solvent effects. For the latter, explicit solvent simulations with increasing number of snapshots were performed for two conformers of an eight amino acid sequence. In conclusion, the empirical approaches neither provide the expected magnitude nor the patterns of NMR chemical shifts determined by the clearly more costly ab initio methods upon structural changes. This restricts the use of empirical prediction programs in studies where peptide and protein structures are utilized for the NMR chemical shift evaluation such as in NMR refinement processes, structural model verifications, or calculations of NMR nuclear spin relaxation rates.

Evaluating the Clinical Burden and Mortality Attributable to Antibiotic Resistance: The Disparity of Empirical Data and Simple Model Estimations.

PubMed

Abat, Cédric; Rolain, Jean-Marc; Dubourg, Grégory; Fournier, Pierre-Edouard; Chaudet, Hervé; Raoult, Didier

2017-08-15

Given the proliferation of cataclysmic predictions about antibiotic resistance, cases of which are estimated to amount to 12500 per year in France, we herein decided to compare the empirical clinical microbiology data from our institution with estimates and predictions from 10 major international scientific articles and reports. The analysis of 7 years of antibiotic resistance data from 10 bacterial species and genera of clinical interest from our institution identified no deaths that were directly attributable to extremely drug-resistant bacteria. By comparing our observations to the 10 articles and reports studied herein, we concluded that their results lack empirical data. Interventions are urgently needed to significantly reduce both mortality and the healthcare costs associated with bacterial infections, including the implementation of local and national laboratory data-based surveillance systems for the routine surveillance of antibiotic resistance that would be helpful for a better understanding of how to manage antibiotic-resistant bacteria in the future. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

Multisample cross-validation of a model of childhood posttraumatic stress disorder symptomatology.

PubMed

Anthony, Jason L; Lonigan, Christopher J; Vernberg, Eric M; Greca, Annette M La; Silverman, Wendy K; Prinstein, Mitchell J

2005-12-01

This study is the latest advancement of our research aimed at best characterizing children's posttraumatic stress reactions. In a previous study, we compared existing nosologic and empirical models of PTSD dimensionality and determined the superior model was a hierarchical one with three symptom clusters (Intrusion/Active Avoidance, Numbing/Passive Avoidance, and Arousal; Anthony, Lonigan, & Hecht, 1999). In this study, we cross-validate this model in two populations. Participants were 396 fifth graders who were exposed to either Hurricane Andrew or Hurricane Hugo. Multisample confirmatory factor analysis demonstrated the model's factorial invariance across populations who experienced traumatic events that differed in severity. These results show the model's robustness to characterize children's posttraumatic stress reactions. Implications for diagnosis, classification criteria, and an empirically supported theory of PTSD are discussed.

Around the macrolide - Impact of 3D structure of macrocycles on lipophilicity and cellular accumulation.

PubMed

Koštrun, Sanja; Munic Kos, Vesna; Matanović Škugor, Maja; Palej Jakopović, Ivana; Malnar, Ivica; Dragojević, Snježana; Ralić, Jovica; Alihodžić, Sulejman

2017-06-16

The aim of this study was to investigate lipophilicity and cellular accumulation of rationally designed azithromycin and clarithromycin derivatives at the molecular level. The effect of substitution site and substituent properties on a global physico-chemical profile and cellular accumulation of investigated compounds was studied using calculated structural parameters as well as experimentally determined lipophilicity. In silico models based on the 3D structure of molecules were generated to investigate conformational effect on studied properties and to enable prediction of lipophilicity and cellular accumulation for this class of molecules based on non-empirical parameters. The applicability of developed models was explored on a validation and test sets and compared with previously developed empirical models. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Tree Guidelines for Inland Empire Communities

Treesearch

E.G. McPherson; J.R. Simpson; P.J. Peper; Q. Xiao; D.R. Pittenger; D.R. Hodel

2001-01-01

Communities in the Inland Empire region of California contain over 8 million people, or about 25% of the state’s population. The region’s inhabitants derive great benefit from trees because compared to coastal areas, the summers are hotter and air pollution levels are higher. The region’s climate is still mild enough to grow a diverse mix of trees. The Inland Empire’s...

Why Be a Shrub? A Basic Model and Hypotheses for the Adaptive Values of a Common Growth Form

PubMed Central

Götmark, Frank; Götmark, Elin; Jensen, Anna M.

2016-01-01

Shrubs are multi-stemmed short woody plants, more widespread than trees, important in many ecosystems, neglected in ecology compared to herbs and trees, but currently in focus due to their global expansion. We present a novel model based on scaling relationships and four hypotheses to explain the adaptive significance of shrubs, including a review of the literature with a test of one hypothesis. Our model describes advantages for a small shrub compared to a small tree with the same above-ground woody volume, based on larger cross-sectional stem area, larger area of photosynthetic tissue in bark and stem, larger vascular cambium area, larger epidermis (bark) area, and larger area for sprouting, and faster production of twigs and canopy. These components form our Hypothesis 1 that predicts higher growth rate for a small shrub than a small tree. This prediction was supported by available relevant empirical studies (14 publications). Further, a shrub will produce seeds faster than a tree (Hypothesis 2), multiple stems in shrubs insure future survival and growth if one or more stems die (Hypothesis 3), and three structural traits of short shrub stems improve survival compared to tall tree stems (Hypothesis 4)—all hypotheses have some empirical support. Multi-stemmed trees may be distinguished from shrubs by more upright stems, reducing bending moment. Improved understanding of shrubs can clarify their recent expansion on savannas, grasslands, and alpine heaths. More experiments and other empirical studies, followed by more elaborate models, are needed to understand why the shrub growth form is successful in many habitats. PMID:27507981

Modeling dynamic beta-gamma polymorphic transition in Tin

NASA Astrophysics Data System (ADS)

Chauvin, Camille; Montheillet, Frank; Petit, Jacques; CEA Gramat Collaboration; EMSE Collaboration

2015-06-01

Solid-solid phase transitions in metals have been studied by shock waves techniques for many decades. Recent experiments have investigated the transition during isentropic compression experiments and shock-wave compression and have highlighted the strong influence of the loading rate on the transition. Complementary data obtained with velocity and temperature measurements around the polymorphic transition beta-gamma of Tin on gas gun experiments have displayed the importance of the kinetics of the transition. But, even though this phenomenon is known, modeling the kinetic remains complex and based on empirical formulations. A multiphase EOS is available in our 1D Lagrangian code Unidim. We propose to present the influence of various kinetic laws (either empirical or involving nucleation and growth mechanisms) and their parameters (Gibbs free energy, temperature, pressure) on the transformation rate. We compare experimental and calculated velocities and temperature profiles and we underline the effects of the empirical parameters of these models.

Fan Noise Prediction with Applications to Aircraft System Noise Assessment

NASA Technical Reports Server (NTRS)

Nark, Douglas M.; Envia, Edmane; Burley, Casey L.

2009-01-01

This paper describes an assessment of current fan noise prediction tools by comparing measured and predicted sideline acoustic levels from a benchmark fan noise wind tunnel test. Specifically, an empirical method and newly developed coupled computational approach are utilized to predict aft fan noise for a benchmark test configuration. Comparisons with sideline noise measurements are performed to assess the relative merits of the two approaches. The study identifies issues entailed in coupling the source and propagation codes, as well as provides insight into the capabilities of the tools in predicting the fan noise source and subsequent propagation and radiation. In contrast to the empirical method, the new coupled computational approach provides the ability to investigate acoustic near-field effects. The potential benefits/costs of these new methods are also compared with the existing capabilities in a current aircraft noise system prediction tool. The knowledge gained in this work provides a basis for improved fan source specification in overall aircraft system noise studies.

Comparison between pathogen directed antibiotic treatment and empirical broad spectrum antibiotic treatment in patients with community acquired pneumonia: a prospective randomised study

PubMed Central

van der Eerden, M M; Vlaspolder, F; de Graaff, C S; Groot, T; Bronsveld, W; Jansen, H; Boersma, W

2005-01-01

Background: There is much controversy about the ideal approach to the management of community acquired pneumonia (CAP). Recommendations differ from a pathogen directed approach to an empirical strategy with broad spectrum antibiotics. Methods: In a prospective randomised open study performed between 1998 and 2000, a pathogen directed treatment (PDT) approach was compared with an empirical broad spectrum antibiotic treatment (EAT) strategy according to the ATS guidelines of 1993 in 262 hospitalised patients with CAP. Clinical efficacy was primarily determined by the length of hospital stay (LOS). Secondary outcome parameters for clinical efficacy were assessment of therapeutic failure on antibiotics, 30 day mortality, duration of antibiotic treatment, resolution of fever, side effects, and quality of life. Results: Three hundred and three patients were enrolled in the study; 41 were excluded, leaving 262 with results available for analysis. No significant differences were found between the two treatment groups in LOS, 30 day mortality, clinical failure, or resolution of fever. Side effects, although they did not have a significant influence on the outcome parameters, occurred more frequently in patients in the EAT group than in those in the PDT group (60% v 17%, 95% CI –0.5 to –0.3; p<0.001). Conclusions: An EAT strategy with broad spectrum antibiotics for the management of hospitalised patients with CAP has comparable clinical efficacy to a PDT approach. PMID:16061709

Travel cost demand model based river recreation benefit estimates with on-site and household surveys: Comparative results and a correction procedure

NASA Astrophysics Data System (ADS)

Loomis, John

2003-04-01

Past recreation studies have noted that on-site or visitor intercept surveys are subject to over-sampling of avid users (i.e., endogenous stratification) and have offered econometric solutions to correct for this. However, past papers do not estimate the empirical magnitude of the bias in benefit estimates with a real data set, nor do they compare the corrected estimates to benefit estimates derived from a population sample. This paper empirically examines the magnitude of the recreation benefits per trip bias by comparing estimates from an on-site river visitor intercept survey to a household survey. The difference in average benefits is quite large, with the on-site visitor survey yielding 24 per day trip, while the household survey yields 9.67 per day trip. A simple econometric correction for endogenous stratification in our count data model lowers the benefit estimate to $9.60 per day trip, a mean value nearly identical and not statistically different from the household survey estimate.

Feasibility of quasi-random band model in evaluating atmospheric radiance

NASA Technical Reports Server (NTRS)

Tiwari, S. N.; Mirakhur, N.

1980-01-01

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

Predicting language diversity with complex networks.

PubMed

Raducha, Tomasz; Gubiec, Tomasz

2018-01-01

We analyze the model of social interactions with coevolution of the topology and states of the nodes. This model can be interpreted as a model of language change. We propose different rewiring mechanisms and perform numerical simulations for each. Obtained results are compared with the empirical data gathered from two online databases and anthropological study of Solomon Islands. We study the behavior of the number of languages for different system sizes and we find that only local rewiring, i.e. triadic closure, is capable of reproducing results for the empirical data in a qualitative manner. Furthermore, we cancel the contradiction between previous models and the Solomon Islands case. Our results demonstrate the importance of the topology of the network, and the rewiring mechanism in the process of language change.

Diagnosing Model Errors in Simulations of Solar Radiation on Inclined Surfaces: Preprint

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

Xie, Yu; Sengupta, Manajit

2016-06-01

Transposition models have been widely used in the solar energy industry to simulate solar radiation on inclined PV panels. Following numerous studies comparing the performance of transposition models, this paper aims to understand the quantitative uncertainty in the state-of-the-art transposition models and the sources leading to the uncertainty. Our results suggest that an isotropic transposition model developed by Badescu substantially underestimates diffuse plane-of-array (POA) irradiances when diffuse radiation is perfectly isotropic. In the empirical transposition models, the selection of empirical coefficients and land surface albedo can both result in uncertainty in the output. This study can be used as amore » guide for future development of physics-based transposition models.« less

Diagnosing Model Errors in Simulation of Solar Radiation on Inclined Surfaces

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

Xie, Yu; Sengupta, Manajit

2016-11-21

Transposition models have been widely used in the solar energy industry to simulate solar radiation on inclined PV panels. Following numerous studies comparing the performance of transposition models, this paper aims to understand the quantitative uncertainty in the state-of-the-art transposition models and the sources leading to the uncertainty. Our results show significant differences between two highly used isotropic transposition models with one substantially underestimating the diffuse plane-of-array (POA) irradiances when diffuse radiation is perfectly isotropic. In the empirical transposition models, the selection of empirical coefficients and land surface albedo can both result in uncertainty in the output. This study canmore » be used as a guide for future development of physics-based transposition models.« less

Empirical calibration of the near-infrared Ca II triplet - III. Fitting functions

NASA Astrophysics Data System (ADS)

Cenarro, A. J.; Gorgas, J.; Cardiel, N.; Vazdekis, A.; Peletier, R. F.

2002-02-01

Using a near-infrared stellar library of 706 stars with a wide coverage of atmospheric parameters, we study the behaviour of the CaII triplet strength in terms of effective temperature, surface gravity and metallicity. Empirical fitting functions for recently defined line-strength indices, namely CaT*, CaT and PaT, are provided. These functions can be easily implemented into stellar population models to provide accurate predictions for integrated CaII strengths. We also present a thorough study of the various error sources and their relation to the residuals of the derived fitting functions. Finally, the derived functional forms and the behaviour of the predicted CaII are compared with those of previous works in the field.

Issues in Benchmarking Human Reliability Analysis Methods: A Literature Review

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

Ronald L. Boring; Stacey M. L. Hendrickson; John A. Forester

There is a diversity of human reliability analysis (HRA) methods available for use in assessing human performance within probabilistic risk assessments (PRA). Due to the significant differences in the methods, including the scope, approach, and underlying models, there is a need for an empirical comparison investigating the validity and reliability of the methods. To accomplish this empirical comparison, a benchmarking study comparing and evaluating HRA methods in assessing operator performance in simulator experiments is currently underway. In order to account for as many effects as possible in the construction of this benchmarking study, a literature review was conducted, reviewing pastmore » benchmarking studies in the areas of psychology and risk assessment. A number of lessons learned through these studies are presented in order to aid in the design of future HRA benchmarking endeavors.« less

Compare diagnostic tests using transformation-invariant smoothed ROC curves⋆

PubMed Central

Tang, Liansheng; Du, Pang; Wu, Chengqing

2012-01-01

Receiver operating characteristic (ROC) curve, plotting true positive rates against false positive rates as threshold varies, is an important tool for evaluating biomarkers in diagnostic medicine studies. By definition, ROC curve is monotone increasing from 0 to 1 and is invariant to any monotone transformation of test results. And it is often a curve with certain level of smoothness when test results from the diseased and non-diseased subjects follow continuous distributions. Most existing ROC curve estimation methods do not guarantee all of these properties. One of the exceptions is Du and Tang (2009) which applies certain monotone spline regression procedure to empirical ROC estimates. However, their method does not consider the inherent correlations between empirical ROC estimates. This makes the derivation of the asymptotic properties very difficult. In this paper we propose a penalized weighted least square estimation method, which incorporates the covariance between empirical ROC estimates as a weight matrix. The resulting estimator satisfies all the aforementioned properties, and we show that it is also consistent. Then a resampling approach is used to extend our method for comparisons of two or more diagnostic tests. Our simulations show a significantly improved performance over the existing method, especially for steep ROC curves. We then apply the proposed method to a cancer diagnostic study that compares several newly developed diagnostic biomarkers to a traditional one. PMID:22639484

A Retrospective Study of School Safety Conditions in High Schools Using the Virginia Threat Assessment Guidelines versus Alternative Approaches

ERIC Educational Resources Information Center

Cornell, Dewey; Sheras, Peter; Gregory, Anne; Fan, Xitao

2009-01-01

Threat assessment has been widely recommended as a violence prevention approach for schools, but there are few empirical studies of its use. This nonexperimental study of 280 Virginia public high schools compared 95 high schools using the Virginia threat assessment guidelines (Cornell & Sheras, 2006), 131 following other (i.e., locally…

Online Finance and Economics Courses: A Comparative Study of Course Satisfaction and Outcomes across Learning Models

ERIC Educational Resources Information Center

Wiechowski, Linda; Washburn, Terri L.

2014-01-01

Student learning outcomes and course satisfaction scores are two key considerations when assessing the success of any degree program. This empirical study was based upon more than 3,000 end-of-semester course evaluations collected from 171 courses in the 2010-2011 academic year. The study, conducted at a Midwestern business college, considered the…

National Identity and the History Curriculum in Northern Ireland: An Empirical Study of Students' Ideas and Beliefs.

ERIC Educational Resources Information Center

Barton, Keith C.; McCully, Alan W.

This paper presents preliminary findings from a study of the historical understanding of secondary students age 12-15 years in Northern Ireland. The study investigated the ideas students had about history, the sources of those ideas, how those ideas related to their sense of identity, and how school history compared to other, less formal…

Enhance Learning through BrainDance Movements: An Empirical Study

ERIC Educational Resources Information Center

Chiang, Linda H.; Griego, Orlando

2017-01-01

The purpose of this study was to compare and associate BrainDance activity to a control group on reading scores as well as social, learning, and negative behavior. A total of 40 students in two classrooms participated in this study. A Likert scale and words per minute reading scores followed by quantitative analysis using a t-test to document and…

How Long Should a Training Program Be? A Field Study of "Rules-of-Thumb"

ERIC Educational Resources Information Center

Cole, Nina

2008-01-01

Purpose: This study aims to examine the question of how long a behavioral skills training program should be in order to result in measurable behavioral change. Design/methodology/approach: An empirical field study was conducted to compare two different lengths of time for a managerial skills training program aimed at achieving behavioral change.…

Empirical research in medical ethics: how conceptual accounts on normative-empirical collaboration may improve research practice.

PubMed

Salloch, Sabine; Schildmann, Jan; Vollmann, Jochen

2012-04-13

The methodology of medical ethics during the last few decades has shifted from a predominant use of normative-philosophical analyses to an increasing involvement of empirical methods. The articles which have been published in the course of this so-called 'empirical turn' can be divided into conceptual accounts of empirical-normative collaboration and studies which use socio-empirical methods to investigate ethically relevant issues in concrete social contexts. A considered reference to normative research questions can be expected from good quality empirical research in medical ethics. However, a significant proportion of empirical studies currently published in medical ethics lacks such linkage between the empirical research and the normative analysis. In the first part of this paper, we will outline two typical shortcomings of empirical studies in medical ethics with regard to a link between normative questions and empirical data: (1) The complete lack of normative analysis, and (2) cryptonormativity and a missing account with regard to the relationship between 'is' and 'ought' statements. Subsequently, two selected concepts of empirical-normative collaboration will be presented and how these concepts may contribute to improve the linkage between normative and empirical aspects of empirical research in medical ethics will be demonstrated. Based on our analysis, as well as our own practical experience with empirical research in medical ethics, we conclude with a sketch of concrete suggestions for the conduct of empirical research in medical ethics. High quality empirical research in medical ethics is in need of a considered reference to normative analysis. In this paper, we demonstrate how conceptual approaches of empirical-normative collaboration can enhance empirical research in medical ethics with regard to the link between empirical research and normative analysis.

Empirical research in medical ethics: How conceptual accounts on normative-empirical collaboration may improve research practice

PubMed Central

2012-01-01

Background The methodology of medical ethics during the last few decades has shifted from a predominant use of normative-philosophical analyses to an increasing involvement of empirical methods. The articles which have been published in the course of this so-called 'empirical turn' can be divided into conceptual accounts of empirical-normative collaboration and studies which use socio-empirical methods to investigate ethically relevant issues in concrete social contexts. Discussion A considered reference to normative research questions can be expected from good quality empirical research in medical ethics. However, a significant proportion of empirical studies currently published in medical ethics lacks such linkage between the empirical research and the normative analysis. In the first part of this paper, we will outline two typical shortcomings of empirical studies in medical ethics with regard to a link between normative questions and empirical data: (1) The complete lack of normative analysis, and (2) cryptonormativity and a missing account with regard to the relationship between 'is' and 'ought' statements. Subsequently, two selected concepts of empirical-normative collaboration will be presented and how these concepts may contribute to improve the linkage between normative and empirical aspects of empirical research in medical ethics will be demonstrated. Based on our analysis, as well as our own practical experience with empirical research in medical ethics, we conclude with a sketch of concrete suggestions for the conduct of empirical research in medical ethics. Summary High quality empirical research in medical ethics is in need of a considered reference to normative analysis. In this paper, we demonstrate how conceptual approaches of empirical-normative collaboration can enhance empirical research in medical ethics with regard to the link between empirical research and normative analysis. PMID:22500496

Politics in the Scope of the Vital Interests of Young People

ERIC Educational Resources Information Center

Zvonovskii, Vladimir

2009-01-01

This article reports on an empirical study of young Russians' participation in political life and how they view the influence of politics on their lives. This study investigates, first, the extent to which young people are interested in politics compared to other spheres of public life. Second, it looks at the extent to which political…

Capitalizing on Knowledge from Public Research Institutions: Indications from New Technology-Based Firms in Japan

ERIC Educational Resources Information Center

Lynskey, Michael J.

2010-01-01

Knowledge spillovers from universities and other public research institutions (PRIs) are viewed as essential for innovation. Previous studies examining the impact of such spillovers have been confined to the West, and there are no comparable studies using empirical data from Japan that explore the relationship between spillovers from PRIs and…

Characteristics and Differences of Lifelong Learning Policy Implementation for the Elderly in Thailand

ERIC Educational Resources Information Center

Dhirathiti, Nopraenue S.; Pichitpatja, Pojjana

2018-01-01

The study examined the process of policy implementation of lifelong learning for the elderly in Thailand, covering four main regions within the country. The study empirically compared inputs, processes, outputs, and outcomes of policy implementation in the north, south, northeast, and central regions of Thailand and captured the rigor of policy…

The Conceptualisation of Dreams by Adults with Intellectual Disabilities: Relationship with Theory of Mind Abilities and Verbal Ability

ERIC Educational Resources Information Center

Dodd, A.; Hare, D. J.; Hendy, S.

2008-01-01

Background: Empirical studies suggest that individuals with intellectual disabilities (ID) have difficulties in conceptualising dreams as perceptually private, non-physical, individuated and potentially fictional entities. The aim of the current study was to replicate the results found by Stenfert Kroese et al. using a comparative sample size, and…

The Efficacy of an Immersive 3D Virtual versus 2D Web Environment in Intercultural Sensitivity Acquisition

ERIC Educational Resources Information Center

Coffey, Amy Jo; Kamhawi, Rasha; Fishwick, Paul; Henderson, Julie

2017-01-01

Relatively few studies have empirically tested computer-based immersive virtual environments' efficacy in teaching or enhancing pro-social attitudes, such as intercultural sensitivity. This channel study experiment was conducted (N = 159) to compare what effects, if any, an immersive 3D virtual environment would have upon subjects' intercultural…

Integrating Mobile Multimedia into Textbooks: 2D Barcodes

ERIC Educational Resources Information Center

Uluyol, Celebi; Agca, R. Kagan

2012-01-01

The major goal of this study was to empirically compare text-plus-mobile phone learning using an integrated 2D barcode tag in a printed text with three other conditions described in multimedia learning theory. The method examined in the study involved modifications of the instructional material such that: a 2D barcode was used near the text, the…

Variations of In-Service Training for Primary Mathematics Teachers: An Empirical Study

ERIC Educational Resources Information Center

Selter, Christoph; Gräsel, Cornelia; Reinold, Martin; Trempler, Kati

2015-01-01

Previous findings indicate that the effectiveness of in-service teacher training can be increased by a (pedagogical) content knowledge orientation on the one hand and the stimulation of cooperation among teachers on the other. In this paper, three versions of a multi-phase training program were compared in a quasi-experimental field study with a…

Exploring Equivalent Forms Reliability Using a Key Stage 2 Reading Test

ERIC Educational Resources Information Center

Benton, Tom

2013-01-01

This article outlines an empirical investigation into equivalent forms reliability using a case study of a national curriculum reading test. Within the situation being studied, there has been a genuine attempt to create several equivalent forms and so it is of interest to compare the actual behaviour of the relationship between these forms to the…

The Real-Life-Referent as a Standard for News Perspective Bias.

ERIC Educational Resources Information Center

Barbatsis, Gretchen S.

The concept of news perspective bias necessitates the creation of an empirical standard by which to judge that bias. A study defined and tested a real life referent applicable to planned, sustained news events that have identifiable and accessible participants. The study compared the television news coverage of court ordered busing to achieve…

The Isolated and Combined Effects of Intervention Components on Mathematic Fluency

ERIC Educational Resources Information Center

Hastings, Kimberly A.

2010-01-01

Scope and Method of Study: The scope of the study was to compare empirically supported math fluency interventions to a control group as well as each other. The intervention components were isolated to investigate their initial strength as well as adding them together to investigate if the combined intervention was actually stronger or more…

A Job Corps Study of Relative Cost Benefits, Volume I and II.

ERIC Educational Resources Information Center

Software Systems, Inc., Washington, DC.

This study was undertaken to relate Job Corps training outcomes to the costs of training, in terms of human talent, time, and material resources. Training outcomes or benefits were classified according to Job Corps objectives, then compared to total costs incurred by both training center and enrollee. Empirical validation and other evaluation of…

An Empirical Study of the Career Paths of Senior Educational Administrators in Manitoba, Canada: Implications for Career Development

ERIC Educational Resources Information Center

Wallin, Dawn C.

2012-01-01

This paper conceptualizes queue theory (Tallerico & Blount, 2004) to discuss a mixed-methods study that determined the career patterns of senior educational administrators in public school divisions in Manitoba, Canada, compared by position, context and sex. Findings indicate that queue theory has merit for describing the career paths of…

Active versus Passive Teaching Styles: An Empirical Study of Student Learning Outcomes

ERIC Educational Resources Information Center

Michel, Norbert; Cater, John James, III; Varela, Otmar

2009-01-01

This study compares the impact of an active teaching approach and a traditional (or passive) teaching style on student cognitive outcomes. Across two sections of an introductory business course, one class was taught in an active or nontraditional manner, with a variety of active learning exercises. The second class was taught in a passive or…

Faith Is Confidence: The Implication of Psychosocial Components in Faith-Based Educational Programs on Expressive Communication Skills of Adult Learners

ERIC Educational Resources Information Center

Lynch, Erin M.

2016-01-01

Faith-based programs for adult learners have environmental factors that differentiate them from non-faith based programs, but explicit empirical studies evaluating the impact of the psychosocial factors have been lacking in the literature. This study comparatively examines the achievement level of expressive communication skills as measured…

An empirical study on the utility of BRDF model parameters and topographic parameters for mapping vegetation in a semi-arid region with MISR imagery

USDA-ARS?s Scientific Manuscript database

Multi-angle remote sensing has been proved useful for mapping vegetation community types in desert regions. Based on Multi-angle Imaging Spectro-Radiometer (MISR) multi-angular images, this study compares roles played by Bidirectional Reflectance Distribution Function (BRDF) model parameters with th...

Online Learning in Management Education: An Empirical Study of the Role of Personality Traits

ERIC Educational Resources Information Center

Varela, Otmar E.; Cater, John James, III; Michel, Norbert

2012-01-01

In this study we seek to better understand the outcomes of online education by observing the role of learners' personality traits. Under the premise that the behaviors that maximize learning are contingent on the delivery method, we compared learning outcomes of students participating in four sections of an undergraduate principles of management…

Forgive and Forget: Differences between Decisional and Emotional Forgiveness.

PubMed

Lichtenfeld, Stephanie; Buechner, Vanessa L; Maier, Markus A; Fernández-Capo, Maria

2015-01-01

To forgive and forget is a well-known idiom, which has rarely been looked at empirically. In the current experiment, we investigated differences between emotional and decisional forgiveness on forgetting. The present study provides the first empirical support that emotional forgiveness has a strong influence on subsequent incidental forgetting. Specifically, our results demonstrate that emotional forgiveness leads to substantially higher levels of forgetting in respect to offense relevant traits compared to both decisional forgiveness and no forgiveness. This provides evidence for our hypothesized effect that only individuals who have emotionally forgiven a transgression, and not those who just decided to forgive, subsequently forget offense relevant traits attributed to the transgressor.

A Longitudinal Study of Individual and Organisational Learning

ERIC Educational Resources Information Center

Campbell, Timothy T.; Armstrong, Steven J.

2013-01-01

Purpose: The purpose of this paper is to empirically examine organisational learning (OL) and individual managerial learning and provide a comparative evaluation of the ability of each to generate organisational benefits. Design/methodology/approach: A theoretical model of organisational learning is developed which was then longitudinally tested…

Development, calibration, and validation of performance prediction models for the Texas M-E flexible pavement design system.

DOT National Transportation Integrated Search

2010-08-01

This study was intended to recommend future directions for the development of TxDOTs Mechanistic-Empirical : (TexME) design system. For stress predictions, a multi-layer linear elastic system was evaluated and its validity was : verified by compar...

Self-Management Procedures: A Comparison across the Autism Spectrum

ERIC Educational Resources Information Center

Southall, Candice M.; Gast, David L.

2011-01-01

Individuals with autism spectrum disorders (ASD) have difficulty generalizing learned behavior to varied environments with independence. This review of 24 empirical studies compares self-management as a systematic procedure for modifying one's own behavior, to increase target behaviors in students with either autistic disorder (AD) or…

Religious Conviction, Morality and Social Convention among Finnish Adolescents

ERIC Educational Resources Information Center

Vainio, Annukka

2011-01-01

The assumptions of Kohlberg, Turiel and Shweder regarding the features of moral reasoning were compared empirically. The moral reasoning of Finnish Evangelical Lutheran, Conservative Laestadian and non-religious adolescents was studied using Kohlberg's Moral Judgment Interview and Turiel Rule Transgression Interview methods. Religiosity and choice…

Is There Evidence of Cream Skimming among Nursing Homes following the Publication of the Nursing Home Compare Report Card?

ERIC Educational Resources Information Center

Mukamel, Dana B.; Ladd, Heather; Weimer, David L.; Spector, William D.; Zinn, Jacqueline S.

2009-01-01

Purpose: A national quality report card for nursing homes, Nursing Home Compare, has been published since 2002. It has been shown to have some, albeit limited, positive impact on quality of care. The objective of this study was to test empirically the hypothesis that nursing homes have responded to the publication of the report by adopting cream…

An update on the "empirical turn" in bioethics: analysis of empirical research in nine bioethics journals.

PubMed

Wangmo, Tenzin; Hauri, Sirin; Gennet, Eloise; Anane-Sarpong, Evelyn; Provoost, Veerle; Elger, Bernice S

2018-02-07

A review of literature published a decade ago noted a significant increase in empirical papers across nine bioethics journals. This study provides an update on the presence of empirical papers in the same nine journals. It first evaluates whether the empirical trend is continuing as noted in the previous study, and second, how it is changing, that is, what are the characteristics of the empirical works published in these nine bioethics journals. A review of the same nine journals (Bioethics; Journal of Medical Ethics; Journal of Clinical Ethics; Nursing Ethics; Cambridge Quarterly of Healthcare Ethics; Hastings Center Report; Theoretical Medicine and Bioethics; Christian Bioethics; and Kennedy Institute of Ethics Journal) was conducted for a 12-year period from 2004 to 2015. Data obtained was analysed descriptively and using a non-parametric Chi-square test. Of the total number of original papers (N = 5567) published in the nine bioethics journals, 18.1% (n = 1007) collected and analysed empirical data. Journal of Medical Ethics and Nursing Ethics led the empirical publications, accounting for 89.4% of all empirical papers. The former published significantly more quantitative papers than qualitative, whereas the latter published more qualitative papers. Our analysis reveals no significant difference (χ2 = 2.857; p = 0.091) between the proportion of empirical papers published in 2004-2009 and 2010-2015. However, the increasing empirical trend has continued in these journals with the proportion of empirical papers increasing from 14.9% in 2004 to 17.8% in 2015. This study presents the current state of affairs regarding empirical research published nine bioethics journals. In the quarter century of data that is available about the nine bioethics journals studied in two reviews, the proportion of empirical publications continues to increase, signifying a trend towards empirical research in bioethics. The growing volume is mainly attributable to two journals: Journal of Medical Ethics and Nursing Ethics. This descriptive study further maps the still developing field of empirical research in bioethics. Additional studies are needed to completely map the nature and extent of empirical research in bioethics to inform the ongoing debate about the value of empirical research for bioethics.

A comparative study of golf industry between Yangtze River Delta, China and Central Japan

NASA Astrophysics Data System (ADS)

Yang, Yangfan; Jin, Pingbin; Gong, Huiwen

2018-03-01

As a competition event of the 2016 Olympic Game, golf sport has aroused great attention around the world. And the Yangtze River Delta(YRD) in China, has already got certain basis and qualifications of developing golf industry, but somehow far from meeting the great potential demand of the market. This research selects the Yangtze River Delta (YRD) and Central Japan (CJ), which are indifferent golf developing stages, as the objectives. Comparative studies are being carried out with an aim of revealing the discrepancies of golf industry in selected regions. The correlations between golf industry and regional economic developing level have been explored as well. Mainly based on a geographical perspective, this research presents an initial effort to combine approaches of setting comparative indexes and spatial analysis, so that golf industry of selected regions will be compared in all directions. The results reveal that great gaps exist in YRD and CJ in terms of golf construction, service, and golf consumption. Problems in developing golf industry in YRD are identified based on the empirical results. A long-term golf development in YRD that deviating from the realistic demand is attributed to both government policies and the operational principles that the market subjects hold. Based on a comparative empirical study, suggestions relating to the government as well as the market players are put forward, with an aim of guiding the golf industry to develop in a sustainable way.

Pilot study comparing market orientation culture of businesses and schools of business.

PubMed

Harmon, Harry A; Webster, Robert L; Hammond, Kevin L

2003-08-01

A market orientation culture has been described as one that blends an organization's commitment to customer value with a process of continuously creating superior value for customers. Developing such a culture is further described as (1) obtaining information about customers, competitors, and markets, (2) examining the gathered information from a total organizational perspective, (3) deciding how to deliver superior customer value, and (4) implementing actions to provide value to customers. A market orientation culture focuses on the customer, identifies issues in the competitive environment, and coordinates all functional areas to achieve organizational objectives. Research has found businesses with higher market orientation are more successful in achieving organizational objectives. The measurement of market orientation within businesses has been empirically tested and validated. However, empirical research on market orientation in nonprofit organizations such as universities has not been examined. This study investigated market orientation within the university setting, specifically Schools of Business Administration, and compared these data with previously published data within the business sector. Data for comparative purposes were collected via a national survey. Hypothesis testing was conducted. Results indicated significantly lower market orientation culture within the schools of business as reported by AACSB Business School Deans vis-à-vis managers of business enterprises.

A Theoretical and Empirical Comparison of Three Approaches to Achievement Testing.

ERIC Educational Resources Information Center

Haladyna, Tom; Roid, Gale

Three approaches to the construction of achievement tests are compared: construct, operational, and empirical. The construct approach is based upon classical test theory and measures an abstract representation of the instructional objectives. The operational approach specifies instructional intent through instructional objectives, facet design,…

Ottoman Pacification of the Balkans, 1450-1650 C.E

DTIC Science & Technology

2009-06-12

many of the policies of his father that left the empire with a devalued currency , took lands from charitable trusts and placed them as military...Ottoman Example. A Review Article." Comparative Studies in Society and History 20, no. 4 (1978): 626-629. Skendi, Stavro. " Crypto -Christianity in the

Cognitive Therapy and Assertive Training in the Treatment of Depression in Women.

ERIC Educational Resources Information Center

LaPointe, Karen A.

Little empirical study has been done on the efficacy of the variety of psychological approaches used to treat depression. The author reviews theoretical points of view: psychoanalytic, cognitive and behavioral, and constructs an experimental design to compare the relative effectiveness of cognitive therapy, assertiveness training and insight…

Gender Differences in Mathematics: Does the Story Need to Be Rewritten?

ERIC Educational Resources Information Center

Brunner, Martin; Krauss, Stefan; Kunter, Mareike

2008-01-01

Empirical studies of high school mathematics typically report small gender differences in favor of boys. The present article challenges this established finding by comparing two competing structural conceptions of mathematical ability. The standard model assumes mathematical ability alone to account for the interindividual differences observed on…

Print and Internet Catalog Shopping: Assessing Attitudes and Intentions.

ERIC Educational Resources Information Center

Vijayasarathy, Leo R.; Jones, Joseph M.

2000-01-01

Findings of an empirical study that compared individuals' attitudes and intentions to shop using print and Internet catalogs suggest that individuals perceived differences between the two catalog media on the shopping factors of reliability, tangibility, and consumer risk. Product value, pre-order information, post-selection information, shopping…

A Comparison of Numerical Problem Solving under Three Types of Calculation Conditions.

ERIC Educational Resources Information Center

Roberts, Dennis M.; Glynn, Shawn M.

1978-01-01

The study reported is the first in a series of investigations designed to empirically test the hypothesis that calculators reduce quantitative working time and increase computational accuracy, and to examine the relative magnitude of benefit that accompanies utilizing calculators compared to manual work. (MN)

Module-Based Professional Development for Teachers: A Cost-Effective Philippine Experiment

ERIC Educational Resources Information Center

San Antonio, Diosdado M.; Morales, Nelson S.; Moral, Leo S.

2011-01-01

This article examines the impact of implementing module-based professional development for teachers (MBPDT) in the Philippines. A mixed-method study, experimental design with empirical surveys and an open-ended questionnaire revealed that the experimental group of teachers had greater professional content knowledge compared with the control group…

Relationship between Defenses, Personality, and Affect during a Stress Task in Normal Adolescents

ERIC Educational Resources Information Center

Steiner, Hans; Erickson, Sarah J.; MacLean, Peggy; Medic, Sanja; Plattner, Belinda; Koopman, Cheryl

2007-01-01

Objective: Although there are extensive data on the relationship between personality and stress reactivity in adults, there is little comparable empirical research with adolescents. This study examines the simultaneous relationships between long term functioning (personality, defenses) and observed stress reactivity (affect) in adolescents.…

Creating Better Schools through Democratic School Leadership

ERIC Educational Resources Information Center

San Antonio, Diosdado M.

2008-01-01

This paper examines the impact of implementing democratic school leadership via advisory school councils in Philippine public secondary schools. Through an experiment with empirical surveys and interviews, this study reveals that the experimental group had higher levels of commitment, empowerment and trust compared with the control group after one…

Towards Improving Educational Decisions by Utilizing Interdisciplinary Research

ERIC Educational Resources Information Center

Klein, Joseph

2014-01-01

Recent neurophysiological advances may support the advisability of delaying decisions when possible and practical. An empirical study, based on an educational dilemma, compared the outcome of postponing an educational decision overnight or for a longer period. 340 teachers read a report on an educational dilemma and gave an immediate opinion.…

Mental Disorder Among Homeless Persons in the United States: An Overview of Recent Empirical Literature.

ERIC Educational Resources Information Center

Robertson, Marjorie J.

1986-01-01

Reviews literature on the homeless reporting higher rates of psychiatric disorder, psychological distress, and previous psychiatric hospitalization compared to the general population. However, understandardized methodology and lack of consistent findings across studies prohibit reliable prevalence estimates of mental disorder among the homeless.…

Diagnosis and Classification in Autism.

ERIC Educational Resources Information Center

Waterhouse, Lynn; And Others

1996-01-01

This study compared four systems for diagnosis of autism (Diagnostic and Statistical Manuals of Mental Disorders III, III-R, and IV, and the International Classification of Disabilities-10) with 2 empirically derived taxa and 3 social subgroups (aloof, passive, and active but odd) in 194 preschool children with social impairment. Findings support…

"We Are Textbook 'Badnekais'!": A Bernsteinian Analysis of Textbook Culture in Science Classrooms

ERIC Educational Resources Information Center

Vijaysimha, Indira

2013-01-01

This article is an empirical study of science teaching practices using a Bernsteinian framework. It provides a comparative analysis through ethnographic examination of pedagogic recontextualisation in different school types--government, private unaided and international. Bernstein drew attention to the process of pedagogic recontextualisation and…

An Empirical Study of Education Divide Diminishment through Online Learning Courses

ERIC Educational Resources Information Center

Hsieh, Ming-Yuan

2017-01-01

According to the swift development of education system, Taiwanese government is always devoting diminishing the educational divide between rural and urban regions. This research focuses on this educational divide by cross-employing the Grey Relational Analysis (GRA) of quantitative analysis and the Fuzzy Set Qualitative Comparative Analysis…

Landscape and regional context differentially affect nest parasitism and nest predation for Wood Thrush in central Virginia, USA (Presentation)

EPA Science Inventory

Many empirical studies have shown that forest-breeding songbirds suffer greater rates of nest predation and nest parasitism in smaller forest patches and in fragmented landscapes. To compare the performance of different metrics of spatial habitat configuration resulting from defo...

Clinical Utility of Cancellation on the WISC-IV

ERIC Educational Resources Information Center

Zhu, Jianjun; Chen, Hsinyi

2013-01-01

This study examined empirical evidence for clinical utility of the Wechsler Intelligence Scale for Children, fourth edition (WISC-IV) cancellation subtest by comparing data from 597 clinical and 597 matched control children. The results of dependent t and sequential logistic regression analyses demonstrated that (a) children with intellectual…

Age, Gender and Health Bias in Counselors: An Empirical Analysis.

ERIC Educational Resources Information Center

Danzinger, Paula R.; Welfel, Elizabeth Reynolds

2000-01-01

Study compares the responses to the Age Bias Questionnaire among professional clinical counselors, psychologists, and clinical social workers. Results indicate that mental health professionals judged older clients significantly less competent and less likely to improve than younger clients. They also judged female clients as less competent than…

Decomposing Achievement Gaps among OECD Countries

ERIC Educational Resources Information Center

Zhang, Liang; Lee, Kristen A.

2011-01-01

In this study, we use decomposition methods on PISA 2006 data to compare student academic performance across OECD countries. We first establish an empirical model to explain the variation in academic performance across individuals, and then use the Oaxaca-Blinder decomposition method to decompose the achievement gap between each of the OECD…

Spatial Resolution, Grayscale, and Error Diffusion Trade-offs: Impact on Display System Design

NASA Technical Reports Server (NTRS)

Gille, Jennifer L. (Principal Investigator)

1996-01-01

We examine technology trade-offs related to grayscale resolution, spatial resolution, and error diffusion for tessellated display systems. We present new empirical results from our psychophysical study of these trade-offs and compare them to the predictions of a model of human vision.

Does It Matter if I Take My Mathematics Test on Computer? A Second Empirical Study of Mode Effects in NAEP

ERIC Educational Resources Information Center

Bennett, Randy Elliot; Braswell, James; Oranje, Andreas; Sandene, Brent; Kaplan, Bruce; Yan, Fred

2008-01-01

This article describes selected results from the Math Online (MOL) study, one of three field investigations sponsored by the National Center for Education Statistics (NCES) to explore the use of new technology in NAEP. Of particular interest in the MOL study was the comparability of scores from paper- and computer-based tests. A nationally…

A Multicenter Evaluation of Prolonged Empiric Antibiotic Therapy in Adult ICUs in the United States.

PubMed

Thomas, Zachariah; Bandali, Farooq; Sankaranarayanan, Jayashri; Reardon, Tom; Olsen, Keith M

2015-12-01

The purpose of this study is to determine the rate of prolonged empiric antibiotic therapy in adult ICUs in the United States. Our secondary objective is to examine the relationship between the prolonged empiric antibiotic therapy rate and certain ICU characteristics. Multicenter, prospective, observational, 72-hour snapshot study. Sixty-seven ICUs from 32 hospitals in the United States. Nine hundred ninety-eight patients admitted to the ICU between midnight on June 20, 2011, and June 21, 2011, were included in the study. None. Antibiotic orders were categorized as prophylactic, definitive, empiric, or prolonged empiric antibiotic therapy. Prolonged empiric antibiotic therapy was defined as empiric antibiotics that continued for at least 72 hours in the absence of adjudicated infection. Standard definitions from the Centers for Disease Control and Prevention were used to determine infection. Prolonged empiric antibiotic therapy rate was determined as the ratio of the total number of empiric antibiotics continued for at least 72 hours divided by the total number of empiric antibiotics. Univariate analysis of factors associated with the ICU prolonged empiric antibiotic therapy rate was conducted using Student t test. A total of 660 unique antibiotics were prescribed as empiric therapy to 364 patients. Of the empiric antibiotics, 333 of 660 (50%) were continued for at least 72 hours in instances where Centers for Disease Control and Prevention infection criteria were not met. Suspected pneumonia accounted for approximately 60% of empiric antibiotic use. The most frequently prescribed empiric antibiotics were vancomycin and piperacillin/tazobactam. ICUs that utilized invasive techniques for the diagnosis of ventilator-associated pneumonia had lower rates of prolonged empiric antibiotic therapy than those that did not, 45.1% versus 59.5% (p = 0.03). No other institutional factor was significantly associated with prolonged empiric antibiotic therapy rate. Half of all empiric antibiotics ordered in critically ill patients are continued for at least 72 hours in absence of adjudicated infection. Additional studies are needed to confirm these findings and determine the risks and benefits of prolonged empiric therapy in the critically ill.

An empirical comparative study on biological age estimation algorithms with an application of Work Ability Index (WAI).

PubMed

Cho, Il Haeng; Park, Kyung S; Lim, Chang Joo

2010-02-01

In this study, we described the characteristics of five different biological age (BA) estimation algorithms, including (i) multiple linear regression, (ii) principal component analysis, and somewhat unique methods developed by (iii) Hochschild, (iv) Klemera and Doubal, and (v) a variant of Klemera and Doubal's method. The objective of this study is to find the most appropriate method of BA estimation by examining the association between Work Ability Index (WAI) and the differences of each algorithm's estimates from chronological age (CA). The WAI was found to be a measure that reflects an individual's current health status rather than the deterioration caused by a serious dependency with the age. Experiments were conducted on 200 Korean male participants using a BA estimation system developed principally under the concept of non-invasive, simple to operate and human function-based. Using the empirical data, BA estimation as well as various analyses including correlation analysis and discriminant function analysis was performed. As a result, it had been confirmed by the empirical data that Klemera and Doubal's method with uncorrelated variables from principal component analysis produces relatively reliable and acceptable BA estimates. 2009 Elsevier Ireland Ltd. All rights reserved.

Empirical correlates for the Minnesota Multiphasic Personality Inventory-2-Restructured Form in a German inpatient sample.

PubMed

Moultrie, Josefine K; Engel, Rolf R

2017-10-01

We identified empirical correlates for the 42 substantive scales of the German language version of the Minnesota Multiphasic Personality Inventory (MMPI)-2-Restructured Form (MMPI-2-RF): Higher Order, Restructured Clinical, Specific Problem, Interest, and revised Personality Psychopathology Five scales. We collected external validity data by means of a 177-item chart review form in a sample of 488 psychiatric inpatients of a German university hospital. We structured our findings along the interpretational guidelines for the MMPI-2-RF and compared them with the validity data published in the tables of the MMPI-2-RF Technical Manual. Our results show significant correlations between MMPI-2-RF scales and conceptually relevant criteria. Most of the results were in line with U.S. validation studies. Some of the differences could be attributed to sample compositions. For most of the scales, construct validity coefficients were acceptable. Taken together, this study amplifies the enlarging body of research on empirical correlates of the MMPI-2-RF scales in a new sample. The study suggests that the interpretations given in the MMPI-2-RF manual may be generalizable to the German language MMPI-2-RF. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Jackknife variance of the partial area under the empirical receiver operating characteristic curve.

PubMed

Bandos, Andriy I; Guo, Ben; Gur, David

2017-04-01

Receiver operating characteristic analysis provides an important methodology for assessing traditional (e.g., imaging technologies and clinical practices) and new (e.g., genomic studies, biomarker development) diagnostic problems. The area under the clinically/practically relevant part of the receiver operating characteristic curve (partial area or partial area under the receiver operating characteristic curve) is an important performance index summarizing diagnostic accuracy at multiple operating points (decision thresholds) that are relevant to actual clinical practice. A robust estimate of the partial area under the receiver operating characteristic curve is provided by the area under the corresponding part of the empirical receiver operating characteristic curve. We derive a closed-form expression for the jackknife variance of the partial area under the empirical receiver operating characteristic curve. Using the derived analytical expression, we investigate the differences between the jackknife variance and a conventional variance estimator. The relative properties in finite samples are demonstrated in a simulation study. The developed formula enables an easy way to estimate the variance of the empirical partial area under the receiver operating characteristic curve, thereby substantially reducing the computation burden, and provides important insight into the structure of the variability. We demonstrate that when compared with the conventional approach, the jackknife variance has substantially smaller bias, and leads to a more appropriate type I error rate of the Wald-type test. The use of the jackknife variance is illustrated in the analysis of a data set from a diagnostic imaging study.

An empirical analysis of ethical and professional issues in physicians' advertising: A comparative cross-sectional study.

PubMed

Moser, H Ronald; Stevens, Robert; Loudon, David

2016-01-01

The purpose of this study is to investigate current attitudes and opinions of physicians' advertising and to compare them to the attitudes expressed 10 years previously. This study was designed to determine (a) consumers' attitudes toward advertising by physicians, and (b) whether age, occupation, income, education, or sex of consumer accounted for any significant difference in attitudes toward physicians who advertise. The study seems to confirm the belief of many marketing professionals that advertising and marketing do not have a place in the management and operation of professional services.

Comparison of artificial intelligence methods and empirical equations to estimate daily solar radiation

NASA Astrophysics Data System (ADS)

Mehdizadeh, Saeid; Behmanesh, Javad; Khalili, Keivan

2016-08-01

In the present research, three artificial intelligence methods including Gene Expression Programming (GEP), Artificial Neural Networks (ANN) and Adaptive Neuro-Fuzzy Inference System (ANFIS) as well as, 48 empirical equations (10, 12 and 26 equations were temperature-based, sunshine-based and meteorological parameters-based, respectively) were used to estimate daily solar radiation in Kerman, Iran in the period of 1992-2009. To develop the GEP, ANN and ANFIS models, depending on the used empirical equations, various combinations of minimum air temperature, maximum air temperature, mean air temperature, extraterrestrial radiation, actual sunshine duration, maximum possible sunshine duration, sunshine duration ratio, relative humidity and precipitation were considered as inputs in the mentioned intelligent methods. To compare the accuracy of empirical equations and intelligent models, root mean square error (RMSE), mean absolute error (MAE), mean absolute relative error (MARE) and determination coefficient (R2) indices were used. The results showed that in general, sunshine-based and meteorological parameters-based scenarios in ANN and ANFIS models presented high accuracy than mentioned empirical equations. Moreover, the most accurate method in the studied region was ANN11 scenario with five inputs. The values of RMSE, MAE, MARE and R2 indices for the mentioned model were 1.850 MJ m-2 day-1, 1.184 MJ m-2 day-1, 9.58% and 0.935, respectively.

DSM-5's posttraumatic stress disorder with dissociative symptoms: challenges and future directions.

PubMed

Dorahy, Martin J; van der Hart, Onno

2015-01-01

The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, formally recognizes a dissociative subtype of posttraumatic stress disorder (PTSD; PTSD with dissociative symptoms). This nomenclative move will boost empirical and theoretical efforts to further understand the links between dissociation, trauma, and PTSD. This article examines the empirical literature showing that patients with PTSD can be divided into 2 different groups based on their neurobiology, psychological symptom profile, history of exposure to early relational trauma, and depersonalization/derealization symptoms. It then explores the conceptual and empirical challenges of conceiving 1 of these types as reflecting a "dissociative" type of PTSD. First, this classification is based on the presence of a limited subset of dissociative symptoms (i.e., depersonalization, derealization). This sets aside an array of positive and negative psychoform and somatoform dissociative symptoms that may be related to PTSD. Second, empirical evidence suggests heightened dissociation in PTSD compared to many other disorders, indicating that dissociation is relevant to PTSD more broadly rather than simply to the so-called dissociative subtype. This article sets out important issues to be examined in the future study of dissociation in PTSD, which needs to be informed by solid conceptual understandings of dissociation.

Empirical and semi-analytical models for predicting peak outflows caused by embankment dam failures

NASA Astrophysics Data System (ADS)

Wang, Bo; Chen, Yunliang; Wu, Chao; Peng, Yong; Song, Jiajun; Liu, Wenjun; Liu, Xin

2018-07-01

Prediction of peak discharge of floods has attracted great attention for researchers and engineers. In present study, nine typical nonlinear mathematical models are established based on database of 40 historical dam failures. The first eight models that were developed with a series of regression analyses are purely empirical, while the last one is a semi-analytical approach that was derived from an analytical solution of dam-break floods in a trapezoidal channel. Water depth above breach invert (Hw), volume of water stored above breach invert (Vw), embankment length (El), and average embankment width (Ew) are used as independent variables to develop empirical formulas of estimating the peak outflow from breached embankment dams. It is indicated from the multiple regression analysis that a function using the former two variables (i.e., Hw and Vw) produce considerably more accurate results than that using latter two variables (i.e., El and Ew). It is shown that the semi-analytical approach works best in terms of both prediction accuracy and uncertainty, and the established empirical models produce considerably reasonable results except the model only using El. Moreover, present models have been compared with other models available in literature for estimating peak discharge.

The use of Theory in Family Therapy Research: Content Analysis and Update.

PubMed

Chen, Ruoxi; Hughes, Alexandria C; Austin, Jason P

2017-07-01

In this study, we evaluated 275 empirical studies from Journal of Marital and Family Therapy and Family Process from 2010 to 2015 on their use of theory, and compared our findings to those of a similar previous analysis (Hawley & Geske, 2000). Overall, theory seems to have become much better incorporated in empirical family therapy research, with only 16.4% of the articles not using theory in either their introductory or discussion sections. Theory appeared better incorporated in the introductory sections than in the discussion sections. Systems theory remained the most commonly used conceptual framework, followed by attachment theory. We discuss areas for improving theory incorporation in family therapy research, and offer suggestions for both family therapy researchers and educators. © 2017 American Association for Marriage and Family Therapy.

Predicting language diversity with complex networks

PubMed Central

Gubiec, Tomasz

2018-01-01

We analyze the model of social interactions with coevolution of the topology and states of the nodes. This model can be interpreted as a model of language change. We propose different rewiring mechanisms and perform numerical simulations for each. Obtained results are compared with the empirical data gathered from two online databases and anthropological study of Solomon Islands. We study the behavior of the number of languages for different system sizes and we find that only local rewiring, i.e. triadic closure, is capable of reproducing results for the empirical data in a qualitative manner. Furthermore, we cancel the contradiction between previous models and the Solomon Islands case. Our results demonstrate the importance of the topology of the network, and the rewiring mechanism in the process of language change. PMID:29702699

On the empirical determination of positron trapping coefficient at nano-scale helium bubbles in steels irradiated in spallation target

NASA Astrophysics Data System (ADS)

Krsjak, Vladimir; Kuriplach, Jan; Vieh, Christiane; Peng, Lei; Dai, Yong

2018-06-01

In the present work, the specific positron trapping rate of small helium bubbles was empirically derived from positron annihilation lifetime spectroscopy (PALS) and transmission electron microscopy (TEM) studies of Fe9Cr martensitic steels. Both techniques are well known to be sensitive to nanometer-sized helium-filled cavities induced during irradiation in a mixed proton-neutron spectrum of spallation target. Complementary TEM and PALS studies show that positrons are being trapped to these defects at a rate of 1.2 ± 0.8 × 10-14 m3s-1. This suggests that helium bubbles in ferritic/martensitic steels are attractive traps for positrons comparable to mono-vacancies and quantitative analysis of the bubbles by PALS technique is plausible.

Study of the cross-market effects of Brexit based on the improved symbolic transfer entropy GARCH model—An empirical analysis of stock–bond correlations

PubMed Central

Chen, Xiurong; Zhao, Rubo

2017-01-01

In this paper, we study the cross-market effects of Brexit on the stock and bond markets of nine major countries in the world. By incorporating information theory, we introduce the time-varying impact weights based on symbolic transfer entropy to improve the traditional GARCH model. The empirical results show that under the influence of Brexit, flight-to-quality not only commonly occurs between the stocks and bonds of each country but also simultaneously occurs among different countries. We also find that the accuracy of the time-varying symbolic transfer entropy GARCH model proposed in this paper has been improved compared to the traditional GARCH model, which indicates that it has a certain practical application value. PMID:28817712

Performance Analysis of Transposition Models Simulating Solar Radiation on Inclined Surfaces

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

Xie, Yu; Sengupta, Manajit

2016-06-02

Transposition models have been widely used in the solar energy industry to simulate solar radiation on inclined photovoltaic panels. Following numerous studies comparing the performance of transposition models, this work aims to understand the quantitative uncertainty in state-of-the-art transposition models and the sources leading to the uncertainty. Our results show significant differences between two highly used isotropic transposition models, with one substantially underestimating the diffuse plane-of-array irradiances when diffuse radiation is perfectly isotropic. In the empirical transposition models, the selection of the empirical coefficients and land surface albedo can both result in uncertainty in the output. This study can bemore » used as a guide for the future development of physics-based transposition models and evaluations of system performance.« less

A Comparison of Approaches for Setting Proficiency Standards.

ERIC Educational Resources Information Center

Koffler, Stephen L.

This research compared the cut-off scores estimated from an empirical procedure (Contrasting group method) to those determined from a more theoretical process (Nedelsky method). A methodological and statistical framework was also provided for analysis of the data to obtain the most appropriate standard using the empirical procedure. Data were…

Evaluation of current Louisiana flexible pavement structures using PMS data and new mechanistic-empirical pavement design guide.

DOT National Transportation Integrated Search

2012-04-01

The new Mechanistic-Empirical Pavement Design Guide (MEPDG) developed under the National Cooperative Highway Research Program (NCHRP) Project 1-37A represents a major change as compared to the 1993 AASHTO Pavement Design Guide. The MEPDG provides a r...

Evaluation of current Louisiana flexible pavement structures using PMS data and new mechanistic-empirical pavement design guide : tech summary.

DOT National Transportation Integrated Search

2012-04-01

The new Mechanistic-Empirical Pavement Design Guide (MEPDG) developed under the National Cooperative Highway : Research Program (NCHRP) Project 1-37A represents a major change as compared to the 1993 AASHTO Pavement : Design Guide. MEPDG provides a r...

Clusters of Colleges and Universities: An Empirically Determined System.

ERIC Educational Resources Information Center

Korb, Roslyn

A technique for classifying higher education institutions was developed in order to identify homogenous subsets of institutions and to compare an institution with its empirically determined peers. The majority of the data were obtained from a 4-year longitudinal file that merged the finance, faculty, enrollment, and institutional characteristics…

Are Science Comics a Good Medium for Science Communication? The Case for Public Learning of Nanotechnology

ERIC Educational Resources Information Center

Lin, Shu-Fen; Lin, Huann-shyang; Lee, Ling; Yore, Larry D.

2015-01-01

Comic books possessing the features of humour, narrative, and visual representation are deemed as a potential medium for science communication; however, empirical studies exploring the effects of comics are scarce. The purposes of this study were to examine and compare the impacts of a comic book and a text booklet on conveying the concepts of…

Government Stance and Internal Diversity of Protest: A Comparative Study of Protest against the War in Iraq in Eight Countries

ERIC Educational Resources Information Center

Walgrave, Stefaan; Verhulst, Joris

2009-01-01

This study tackles the question to what extent the composition of protest events is determined by the stance of governments. Established contextual theories do not formulate propositions on how context affects individual protesters. The article engages in empirically testing whether the macro-context affects the internal diversity of the crowds…

Monopoly vs. Markets: The Empirical Evidence on Private Schools & School Choice. School Choice Issues in Depth

ERIC Educational Resources Information Center

Forster, Greg

2007-01-01

This study presents new findings comparing public and private high schools using top-quality data from the Education Longitudinal Study (ELS), a long-term research project sponsored by the U.S. Department of Education. The ELS project tracks individual data on thousands of students, allowing researchers to conduct much better analyses than are…

The Efficiency of Different Online Learning Media--An Empirical Study

ERIC Educational Resources Information Center

Köbler, Franziska J.; Nitzschner, Marco M.

2014-01-01

In the current study, it was examined whether successful learning is related to using different types of media. We compared the comprehension of an economic concept in novices (N = 82) under three conditions: a Wikipedia article, a funny, and a serious YouTube video. The media were presented in English which is a foreign language to most of the…

Organisational Culture: An Exploratory Study Comparing Faculties' Perspectives within Public and Private Universities in Malaysia

ERIC Educational Resources Information Center

Ramachandran, Sharimllah Devi; Chong, Siong Choy; Ismail, Hishamuddin

2011-01-01

Purpose: The main objective of this paper to study the organisational culture (OC) in private and public higher education institutions (HEIs) from the perspective of faculty members in order to provide empirical insights on the differences and consequently pave an avenue for cross-learning. Design/methodology/approach: Data were collected from 594…

The Skeletons in Our Closet: E-Learning Tools and What Happens When One Side Does Not Fit All

ERIC Educational Resources Information Center

Van Nuland, Sonya E.; Rogers, Kem A.

2017-01-01

In the anatomical sciences, e-learning tools have become a critical component of teaching anatomy when physical space and cadaveric resources are limited. However, studies that use empirical evidence to compare their efficacy to visual-kinesthetic learning modalities are scarce. The study examined how a visual-kinesthetic experience, involving a…

An Empirical Study Comparing Curriculum-Embedded Assessment and Traditional Aptitude Measures for Predicting Job-Related Outcomes for Students with Disabilities.

ERIC Educational Resources Information Center

Swisher, Judith D.; Green, Samuel B.

1998-01-01

This study examined whether a curriculum-embedded assessment, the Practical Assessment Exploration System (PAES), could be used with students with disabilities to predict job-related outcomes three to five years later. Results with 103 students assessed in seventh and eighth grades suggest that the PAES offers some promise for evaluating student…

Uses of Multivariate Analytical Techniques in Online and Blended Business Education: An Assessment of Current Practice and Recommendations for Future Research

ERIC Educational Resources Information Center

Arbaugh, J. B.; Hwang, Alvin

2013-01-01

Seeking to assess the analytical rigor of empirical research in management education, this article reviews the use of multivariate statistical techniques in 85 studies of online and blended management education over the past decade and compares them with prescriptions offered by both the organization studies and educational research communities.…

An Approachment to Cooperative Learning in Higher Education: Comparative Study of Teaching Methods in Engineering

ERIC Educational Resources Information Center

Estébanez, Raquel Pérez

2017-01-01

In the way of continuous improvement in teaching methods this paper explores the effects of Cooperative Learning (CL) against Traditional Learning (TL) in academic performance of students in higher education in two groups of the first course of Computer Science Degree at the university. The empirical study was conducted through an analysis of…

Backward Blocking and Interference between Cues Are Empirically Equivalent in Non-Causally Framed Learning Tasks

ERIC Educational Resources Information Center

Luque, David; Moris, Joaquin; Orgaz, Cristina; Cobos, Pedro L.; Matute, Helena

2011-01-01

Backward blocking (BB) and interference between cues (IbC) are cue competition effects produced by very similar manipulations. In a standard BB design, both effects might occur simultaneously, which implies a potential problem for studying BB. In the present study with humans, the magnitude of both effects was compared using a non-causal scenario…

Data mining: comparing the empiric CFS to the Canadian ME/CFS case definition.

PubMed

Jason, Leonard A; Skendrovic, Beth; Furst, Jacob; Brown, Abigail; Weng, Angela; Bronikowski, Christine

2012-01-01

This article contrasts two case definitions for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). We compared the empiric CFS case definition (Reeves et al., 2005) and the Canadian ME/CFS clinical case definition (Carruthers et al., 2003) with a sample of individuals with CFS versus those without. Data mining with decision trees was used to identify the best items to identify patients with CFS. Data mining is a statistical technique that was used to help determine which of the survey questions were most effective for accurately classifying cases. The empiric criteria identified about 79% of patients with CFS and the Canadian criteria identified 87% of patients. Items identified by the Canadian criteria had more construct validity. The implications of these findings are discussed. © 2011 Wiley Periodicals, Inc.

Comparison between volatility return intervals of the S&P 500 index and two common models

NASA Astrophysics Data System (ADS)

Vodenska-Chitkushev, I.; Wang, F. Z.; Weber, P.; Yamasaki, K.; Havlin, S.; Stanley, H. E.

2008-01-01

We analyze the S&P 500 index data for the 13-year period, from January 1, 1984 to December 31, 1996, with one data point every 10 min. For this database, we study the distribution and clustering of volatility return intervals, which are defined as the time intervals between successive volatilities above a certain threshold q. We find that the long memory in the volatility leads to a clustering of above-median as well as below-median return intervals. In addition, it turns out that the short return intervals form larger clusters compared to the long return intervals. When comparing the empirical results to the ARMA-FIGARCH and fBm models for volatility, we find that the fBm model predicts scaling better than the ARMA-FIGARCH model, which is consistent with the argument that both ARMA-FIGARCH and fBm capture the long-term dependence in return intervals to a certain extent, but only fBm accounts for the scaling. We perform the Student's t-test to compare the empirical data with the shuffled records, ARMA-FIGARCH and fBm. We analyze separately the clusters of above-median return intervals and the clusters of below-median return intervals for different thresholds q. We find that the empirical data are statistically different from the shuffled data for all thresholds q. Our results also suggest that the ARMA-FIGARCH model is statistically different from the S&P 500 for intermediate q for both above-median and below-median clusters, while fBm is statistically different from S&P 500 for small and large q for above-median clusters and for small q for below-median clusters. Neither model can fully explain the entire regime of q studied.

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.

Understanding hind limb lameness signs in horses using simple rigid body mechanics.

PubMed

Starke, S D; May, S A; Pfau, T

2015-09-18

Hind limb lameness detection in horses relies on the identification of movement asymmetry which can be based on multiple pelvic landmarks. This study explains the poorly understood relationship between hind limb lameness pointers, related to the tubera coxae and sacrum, based on experimental data in context of a simple rigid body model. Vertical displacement of tubera coxae and sacrum was quantified experimentally in 107 horses with varying lameness degrees. A geometrical rigid-body model of pelvis movement during lameness was created in Matlab. Several asymmetry measures were calculated and contrasted. Results showed that model predictions for tubera coxae asymmetry during lameness matched experimental observations closely. Asymmetry for sacrum and comparative tubera coxae movement showed a strong association both empirically (R(2)≥ 0.92) and theoretically. We did not find empirical or theoretical evidence for a systematic, pronounced adaptation in the pelvic rotation pattern with increasing lameness. The model showed that the overall range of movement between tubera coxae does not allow the appreciation of asymmetry changes beyond mild lameness. When evaluating movement relative to the stride cycle we did find empirical evidence for asymmetry being slightly more visible when comparing tubera coxae amplitudes rather than sacrum amplitudes, although variation exists for mild lameness. In conclusion, the rigidity of the equine pelvis results in tightly linked movement trajectories of different pelvic landmarks. The model allows the explanation of empirical observations in the context of the underlying mechanics, helping the identification of potentially limited assessment choices when evaluating gait. Copyright © 2015 Elsevier Ltd. All rights reserved.

Stroke mortality variations in South-East Asia: empirical evidence from the field.

PubMed

Hoy, Damian G; Rao, Chalapati; Hoa, Nguyen Phuong; Suhardi, S; Lwin, Aye Moe Moe

2013-10-01

Stroke is a leading cause of death in Asia; however, many estimates of stroke mortality are based on epidemiological models rather than empirical data. Since 2005, initiatives have been undertaken in a number of Asian countries to strengthen and analyse vital registration data. This has increased the availability of empirical data on stroke mortality. The aim of this paper is to present estimates of stroke mortality for Indonesia, Myanmar, Viet Nam, Thailand, and Malaysia, which have been derived using these empirical data. Age-specific stroke mortality rates were calculated in each of the five countries, and adjusted for data completeness or misclassification where feasible. All data were age-standardized and the resulting rates were compared with World Health Organization estimates, which are largely based on epidemiological models. Using empirical data, stroke ranked as the leading cause of death in all countries except Malaysia, where it ranked as the second leading cause. Age-standardized rates for males ranged from 94 per 100,000 in Thailand, to over 300 per 100,000 in Indonesia. In all countries, rates were higher for males than for females, and those compiled from empirical data were generally higher than modelled estimates published by World Health Organization. This study highlights the extent of stroke mortality in selected Asian countries, and provides important baseline information to investigate the aetiology of stroke in Asia and design appropriate public health strategies to address the rapidly growing burden from stroke. © 2012 The Authors. International Journal of Stroke © 2012 World Stroke Organization.

A comparison of likelihood ratio tests and Rao's score test for three separable covariance matrix structures.

PubMed

Filipiak, Katarzyna; Klein, Daniel; Roy, Anuradha

2017-01-01

The problem of testing the separability of a covariance matrix against an unstructured variance-covariance matrix is studied in the context of multivariate repeated measures data using Rao's score test (RST). The RST statistic is developed with the first component of the separable structure as a first-order autoregressive (AR(1)) correlation matrix or an unstructured (UN) covariance matrix under the assumption of multivariate normality. It is shown that the distribution of the RST statistic under the null hypothesis of any separability does not depend on the true values of the mean or the unstructured components of the separable structure. A significant advantage of the RST is that it can be performed for small samples, even smaller than the dimension of the data, where the likelihood ratio test (LRT) cannot be used, and it outperforms the standard LRT in a number of contexts. Monte Carlo simulations are then used to study the comparative behavior of the null distribution of the RST statistic, as well as that of the LRT statistic, in terms of sample size considerations, and for the estimation of the empirical percentiles. Our findings are compared with existing results where the first component of the separable structure is a compound symmetry (CS) correlation matrix. It is also shown by simulations that the empirical null distribution of the RST statistic converges faster than the empirical null distribution of the LRT statistic to the limiting χ 2 distribution. The tests are implemented on a real dataset from medical studies. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Management of infection during chemotherapy for acute leukemia in Japan: a nationwide questionnaire-based survey by the Japan Adult Leukemia Study Group.

PubMed

Kimura, Shun-Ichi; Fujita, Hiroyuki; Kato, Hideaki; Hiramoto, Nobuhiro; Hosono, Naoko; Takahashi, Tsutomu; Shigeno, Kazuyuki; Hatsumi, Naoko; Minamiguchi, Hitoshi; Miyatake, Junichi; Handa, Hiroshi; Akiyama, Nobu; Kanda, Yoshinobu; Yoshida, Minoru; Kiyoi, Hitoshi; Miyazaki, Yasushi; Naoe, Tomoki

2017-11-01

We performed a nationwide questionnaire-based survey to evaluate the current clinical practices of infectious complications during chemotherapy for acute leukemia in Japan. We e-mailed a questionnaire to member institutions of the Japan Adult Leukemia Study Group in September, 2013. The questionnaire consisted of 50 multiple-choice questions covering therapeutic environment, antimicrobial prophylaxis, screening test during neutropenia, empirical therapy for febrile neutropenia, and the use of granulocyte-colony stimulating factor. The results were compared to those of previous surveys conducted in 2001 and 2007, and also to the recommendations described in the guidelines. Usable responses were received from 141 out of 222 (63.5%) institutions. Chemotherapy for acute myeloid leukemia was performed in protective environment in 90% of the institutions, which increased compared to previous survey (76%). Fluoroquinolones and fluconazole were the most commonly used antimicrobial agents for antibacterial and antifungal prophylaxis, followed by sulfamethoxazole-trimethoprim and itraconazole, respectively. In empirical therapy for febrile neutropenia, monotherapy with β-lactum antibiotics was the first-line therapy in most of the institutions. While empirical antifungal therapy was adopted for persistent fever in more than half of the institutions, preemptive/presumptive therapy was also used in approximately 40% of the institutions. Most of the clinicians were reluctant to use granulocyte-colony stimulating factor routinely in chemotherapy for acute myeloid leukemia. This study clarified the current clinical practices of infectious complications during chemotherapy for acute leukemia and would provide important information for the development of a suitable guideline in Japan.

Clinical trial: a randomized trial of early endoscopy, Helicobacter pylori testing and empirical therapy for the management of dyspepsia in primary care.

PubMed

Duggan, A E; Elliott, C A; Miller, P; Hawkey, C J; Logan, R F A

2009-01-01

Early endoscopy, Helicobacter pylori eradication and empirical acid suppression are commonly used dyspepsia management strategies in primary care but have not been directly compared in a single trial. To compare endoscopy, H. pylori test and refer, H. pylori test and treat and empirical acid suppression for dyspepsia in primary care. Patients presenting to their general practitioner with dyspepsia were randomized to endoscopy, H. pylori'test and treat', H. pylori test and endoscope positives, or empirical therapy with symptoms, patient satisfaction, healthcare costs and cost effectiveness at 12 months being the outcomes. At 2 months, the proportion of patients reporting no or minimal dyspeptic symptoms ranged from 74% for those having early endoscopy to 55% for those on empirical therapy (P = 0.009), but at 1 year, there was little difference among the four strategies. Early endoscopy was associated with fewer subsequent consultations for dyspepsia (P = 0.003). 'Test and treat' resulted in fewer endoscopies overall and was most cost-effective over a range of cost assumptions. Empirical therapy resulted in the lowest initial costs, but the highest rate of subsequent endoscopy. Gastro-oesophageal cancers were found in four patients randomized to the H. pylori testing strategies. While early endoscopy offered some advantages 'Test and treat' was the most cost-effective strategy. In older patients, early endoscopy may be an appropriate strategy in view of the greater risk of malignant disease. © 2008 The Authors. Journal compilation © 2008 Blackwell Publishing Ltd.

Comparing the model-simulated global warming signal to observations using empirical estimates of unforced noise.

PubMed

Brown, Patrick T; Li, Wenhong; Cordero, Eugene C; Mauget, Steven A

2015-04-21

The comparison of observed global mean surface air temperature (GMT) change to the mean change simulated by climate models has received much public and scientific attention. For a given global warming signal produced by a climate model ensemble, there exists an envelope of GMT values representing the range of possible unforced states of the climate system (the Envelope of Unforced Noise; EUN). Typically, the EUN is derived from climate models themselves, but climate models might not accurately simulate the correct characteristics of unforced GMT variability. Here, we simulate a new, empirical, EUN that is based on instrumental and reconstructed surface temperature records. We compare the forced GMT signal produced by climate models to observations while noting the range of GMT values provided by the empirical EUN. We find that the empirical EUN is wide enough so that the interdecadal variability in the rate of global warming over the 20(th) century does not necessarily require corresponding variability in the rate-of-increase of the forced signal. The empirical EUN also indicates that the reduced GMT warming over the past decade or so is still consistent with a middle emission scenario's forced signal, but is likely inconsistent with the steepest emission scenario's forced signal.

Comparing the model-simulated global warming signal to observations using empirical estimates of unforced noise

PubMed Central

Brown, Patrick T.; Li, Wenhong; Cordero, Eugene C.; Mauget, Steven A.

2015-01-01

The comparison of observed global mean surface air temperature (GMT) change to the mean change simulated by climate models has received much public and scientific attention. For a given global warming signal produced by a climate model ensemble, there exists an envelope of GMT values representing the range of possible unforced states of the climate system (the Envelope of Unforced Noise; EUN). Typically, the EUN is derived from climate models themselves, but climate models might not accurately simulate the correct characteristics of unforced GMT variability. Here, we simulate a new, empirical, EUN that is based on instrumental and reconstructed surface temperature records. We compare the forced GMT signal produced by climate models to observations while noting the range of GMT values provided by the empirical EUN. We find that the empirical EUN is wide enough so that the interdecadal variability in the rate of global warming over the 20th century does not necessarily require corresponding variability in the rate-of-increase of the forced signal. The empirical EUN also indicates that the reduced GMT warming over the past decade or so is still consistent with a middle emission scenario's forced signal, but is likely inconsistent with the steepest emission scenario's forced signal. PMID:25898351

Discovering new events beyond the catalogue—application of empirical matched field processing to Salton Sea geothermal field seismicity

DOE PAGES

Wang, Jingbo; Templeton, Dennise C.; Harris, David B.

2015-07-30

Using empirical matched field processing (MFP), we compare 4 yr of continuous seismic data to a set of 195 master templates from within an active geothermal field and identify over 140 per cent more events than were identified using traditional detection and location techniques alone. In managed underground reservoirs, a substantial fraction of seismic events can be excluded from the official catalogue due to an inability to clearly identify seismic-phase onsets. Empirical MFP can improve the effectiveness of current seismic detection and location methodologies by using conventionally located events with higher signal-to-noise ratios as master events to define wavefield templatesmore » that could then be used to map normally discarded indistinct seismicity. Since MFP does not require picking, it can be carried out automatically and rapidly once suitable templates are defined. In this application, we extend MFP by constructing local-distance empirical master templates using Southern California Earthquake Data Center archived waveform data of events originating within the Salton Sea Geothermal Field. We compare the empirical templates to continuous seismic data collected between 1 January 2008 and 31 December 2011. The empirical MFP method successfully identifies 6249 additional events, while the original catalogue reported 4352 events. The majority of these new events are lower-magnitude events with magnitudes between M0.2–M0.8. Here, the increased spatial-temporal resolution of the microseismicity map within the geothermal field illustrates how empirical MFP, when combined with conventional methods, can significantly improve seismic network detection capabilities, which can aid in long-term sustainability and monitoring of managed underground reservoirs.« less

Efficient management of marine resources in conflict: an empirical study of marine sand mining, Korea.

PubMed

Kim, Tae-Goun

2009-10-01

This article develops a dynamic model of efficient use of exhaustible marine sand resources in the context of marine mining externalities. The classical Hotelling extraction model is applied to sand mining in Ongjin, Korea and extended to include the estimated marginal external costs that mining imposes on marine fisheries. The socially efficient sand extraction plan is compared with the extraction paths suggested by scientific research. If marginal environmental costs are correctly estimated, the developed efficient extraction plan considering the resource rent may increase the social welfare and reduce the conflicts among the marine sand resource users. The empirical results are interpreted with an emphasis on guidelines for coastal resource management policy.

A computational approach to compare regression modelling strategies in prediction research.

PubMed

Pajouheshnia, Romin; Pestman, Wiebe R; Teerenstra, Steven; Groenwold, Rolf H H

2016-08-25

It is often unclear which approach to fit, assess and adjust a model will yield the most accurate prediction model. We present an extension of an approach for comparing modelling strategies in linear regression to the setting of logistic regression and demonstrate its application in clinical prediction research. A framework for comparing logistic regression modelling strategies by their likelihoods was formulated using a wrapper approach. Five different strategies for modelling, including simple shrinkage methods, were compared in four empirical data sets to illustrate the concept of a priori strategy comparison. Simulations were performed in both randomly generated data and empirical data to investigate the influence of data characteristics on strategy performance. We applied the comparison framework in a case study setting. Optimal strategies were selected based on the results of a priori comparisons in a clinical data set and the performance of models built according to each strategy was assessed using the Brier score and calibration plots. The performance of modelling strategies was highly dependent on the characteristics of the development data in both linear and logistic regression settings. A priori comparisons in four empirical data sets found that no strategy consistently outperformed the others. The percentage of times that a model adjustment strategy outperformed a logistic model ranged from 3.9 to 94.9 %, depending on the strategy and data set. However, in our case study setting the a priori selection of optimal methods did not result in detectable improvement in model performance when assessed in an external data set. The performance of prediction modelling strategies is a data-dependent process and can be highly variable between data sets within the same clinical domain. A priori strategy comparison can be used to determine an optimal logistic regression modelling strategy for a given data set before selecting a final modelling approach.

Development and system identification of a light unmanned aircraft for flying qualities research

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

Peters, M.E.; Andrisani, D. II

This paper describes the design, construction, flight testing and system identification of a light weight remotely piloted aircraft and its use in studying flying qualities in the longitudinal axis. The short period approximation to the longitudinal dynamics of the aircraft was used. Parameters in this model were determined a priori using various empirical estimators. These parameters were then estimated from flight data using a maximum likelihood parameter identification method. A comparison of the parameter values revealed that the stability derivatives obtained from the empirical estimators were reasonably close to the flight test results. However, the control derivatives determined by themore » empirical estimators were too large by a factor of two. The aircraft was also flown to determine how the longitudinal flying qualities of light weight remotely piloted aircraft compared to full size manned aircraft. It was shown that light weight remotely piloted aircraft require much faster short period dynamics to achieve level I flying qualities in an up-and-away flight task.« less

Infant-Directed Speech Enhances Attention to Speech in Deaf Infants with Cochlear Implants

ERIC Educational Resources Information Center

Wang, Yuanyuan; Bergeson, Tonya R.; Houston, Derek M.

2017-01-01

Purpose: Both theoretical models of infant language acquisition and empirical studies posit important roles for attention to speech in early language development. However, deaf infants with cochlear implants (CIs) show reduced attention to speech as compared with their peers with normal hearing (NH; Horn, Davis, Pisoni, & Miyamoto, 2005;…

Crack closure, a literature study

NASA Astrophysics Data System (ADS)

Holmgren, M.

1993-08-01

In this report crack closure is treated. The state of the art is reviewed. Different empirical formulas for determining the crack closure are compared with each other, and their benefits are discussed. Experimental techniques for determining the crack closure stress are discussed, and some results from fatigue tests are also reported. Experimental data from the literature are reported.

Local Linear Observed-Score Equating

ERIC Educational Resources Information Center

Wiberg, Marie; van der Linden, Wim J.

2011-01-01

Two methods of local linear observed-score equating for use with anchor-test and single-group designs are introduced. In an empirical study, the two methods were compared with the current traditional linear methods for observed-score equating. As a criterion, the bias in the equated scores relative to true equating based on Lord's (1980)…

Hard Cases and Soft Concepts of Change and Leadership in Universities. ASHE 1987 Annual Meeting Paper.

ERIC Educational Resources Information Center

Mock, Carol

Empirical hypotheses about organizational change are compared with actual case studies of change and leadership at the University of California (UC) system. The hypotheses are based on the sociological literature on complex organizations and are derived from three perspectives: (1) rational choice and analytic approaches, (2) cognitive…

An Empirical Test of Self-Determination Theory as a Guide to Fostering Environmental Motivation

ERIC Educational Resources Information Center

Darner, Rebekka

2012-01-01

A goal of most environmental education is to motivate students toward environmentally friendly behaviour change. This article describes a study that elucidates how such motivation can be fostered in the classroom. It compared students' development of environmental motivation in a conventional post-secondary environmental biology course and a…

Pedagogy for Developing Critical Thinking in Adolescents: Explicit Instruction Produces Greatest Gains

ERIC Educational Resources Information Center

Marin, Lisa M.; Halpern, Diane F.

2011-01-01

Although the development and transfer of critical thinking skills are recognized as primary goals for education, there is little empirical evidence to help educators decide how to teach in ways that enhance critical thinking. In two studies, we compared explicit and imbedded instructional modes and assessed critical thinking with the Halpern…

Relative User Ratings of MMPI-2 Computer-Based Test Interpretations

ERIC Educational Resources Information Center

Williams, John E.; Weed, Nathan C.

2004-01-01

There are eight commercially available computer-based test interpretations (CBTIs) for the Minnesota Multiphasic Personality Inventory-2 (MMPI-2), of which few have been empirically evaluated. Prospective users of these programs have little scientific data to guide choice of a program. This study compared ratings of these eight CBTIs. Test users…

Analyses and Comparisons of Science Curricula in Japan and the United States.

ERIC Educational Resources Information Center

Jacobson, Willard J.; And Others

An analysis and comparison of science education in Japan and the United States is presented. Studies in comparative science education, including the first and second International Association for the Evaluation of Educational Achievement (IEA) and the Japan and United States Cooperative Science Project, provide an empirical base for some of the…

Supporting Young Children's Learning with Technology at Home and in Preschool

ERIC Educational Resources Information Center

Plowman, Lydia; Stephen, Christine; McPake, Joanna

2010-01-01

We describe two empirical investigations of three- and four-year-old children's uses of technology, one conducted in family homes and the other in preschool settings, with the aim of comparing the ways in which children's learning with technology is supported in these different settings. The studies conceptualise learning within a sociocultural…

Inmate Recidivism as a Measure of Private Prison Performance

ERIC Educational Resources Information Center

Spivak, Andrew L.; Sharp, Susan F.

2008-01-01

The growth of the private corrections industry has elicited interest in the comparative performance of state and private prisons. One way to measure the service quality of private prisons is to examine inmates' postrelease performance. Current empirical evidence is limited to four studies, all conducted in Florida. This analysis replicates and…

Legislative Provisions Underlying Trade Unions' Right to Define Their Organizational Structure

ERIC Educational Resources Information Center

Korobchenko, Victoria V.; Penov, Yury V.; Safonov, Valery A.

2016-01-01

The article contains a comparative analysis of constitutional and other legislative provisions that ensure a trade union's right to define its own administrative structure in European states. The aim of the study is to reveal the management's problems of European trade unions, declarative and empirical mass-character legislative provisions, which…

The Impact of a Simulation Game on Operations Management Education

ERIC Educational Resources Information Center

Pasin, Federico; Giroux, Helene

2011-01-01

This study presents a new simulation game and analyzes its impact on operations management education. The proposed simulation was empirically tested by comparing the number of mistakes during the first and second halves of the game. Data were gathered from 100 teams of four or five undergraduate students in business administration, taking their…

Leadership Challenges and Roles of School Superintendents: A Comparative Study on China and the United States

ERIC Educational Resources Information Center

Przybylski, Robert; Chen, Xuejun; Hu, Liwen

2018-01-01

This conceptual paper using published empirical articles investigated the leadership challenges and roles performed by superintendents in the countries of China and the United States (U.S.). Additionally, a comprehensive search on the educational contexts for both countries was undertaken. The findings assisted in determining similarities and…

Recruitment, Retention and the Minority Teacher Shortage. CPRE Research Report # RR-69

ERIC Educational Resources Information Center

Ingersoll, Richard M.; May, Henry

2011-01-01

This study examines and compares the recruitment and retention of minority and White elementary and secondary teachers and attempts to empirically ground the debate over minority teacher shortages. The data we analyze are from the National Center for Education Statistics' nationally representative Schools and Staffing Survey and its longitudinal…

Landscape and regional context differentially affect nest parasitism and nest predation for Wood Thrush in central Virginia, USA

EPA Science Inventory

Many empirical studies have shown that forest-breeding songbirds, and neotropical migrants in particular, are found in lower abundance in small patches of forest in the Eastern United States compared to similar, but larger patches in the same region. A common hypothesis for the ...

An Institutional Model of Organizational Practice: Financial Reporting at the Fortune 200.

ERIC Educational Resources Information Center

Mezias, Stephen J.

1990-01-01

Compares applied economic models and an institutional model in an empirical study of financial reporting practice at the Fortune 200 between 1962 and 1984. Findings indicate that the institutional model adds significant explanatory power over and above the models currently dominating the applied economics literature. Includes 47 references. (MLH)

Virtual Reality as Treatment for Fear of Flying: A Review of Recent Research

ERIC Educational Resources Information Center

Price, Matthew; Anderson, Page; Rothbaum, Barbara O.

2008-01-01

Virtual reality exposure has recently emerged as an important tool for exposure therapy in the treatment of fear of flying. There have been numerous empirical studies that have evaluated the effectiveness of virtual reality exposure as compared to other treatments including in vivo exposure, progressive muscle relaxation, cognitive therapy,…

Technology-Assisted Learning: A Longitudinal Field Study of Knowledge Category, Learning Effectiveness and Satisfaction in Language Learning

ERIC Educational Resources Information Center

Hui, W.; Hu, P. J.-H.; Clark, T. H. K.; Tam, K. Y.; Milton, J.

2008-01-01

A field experiment compares the effectiveness and satisfaction associated with technology-assisted learning with that of face-to-face learning. The empirical evidence suggests that technology-assisted learning effectiveness depends on the target knowledge category. Building on Kolb's experiential learning model, we show that technology-assisted…

Leading Learning in Asia--Emerging Empirical Insights from Five Societies

ERIC Educational Resources Information Center

Hallinger, Philip; Walker, Allan

2017-01-01

Purpose: The purpose of this paper is to synthesize findings from studies of principal instructional leadership conducted in five East Asian societies. The authors first identify similarities and then differences in approaches to instructional leadership across the societies. Then the findings of the synthesis are compared with broad findings from…

Walk-In Triage Systems in University Counseling Centers

ERIC Educational Resources Information Center

Shaffer, Katharine S.; Love, Michael M.; Chapman, Kelsey M.; Horn, Angela J.; Haak, Patricia P.; Shen, Claire Y. W.

2017-01-01

To meet the complex mental health needs of students, some university counseling centers (UCCs) have implemented walk-in triage intake systems, which have not yet been empirically investigated. This study compared client and clinician differences (N = 5564) between a traditional scheduled intake system (Year 1) and a walk-in triage system (Year 2)…

MEXICANS IN THE UNITED STATES--A PROBLEM IN SOCIAL DIFFERENTIATION.

ERIC Educational Resources Information Center

BROOM, LEONARD; SHEVKY, ESHREF

AN ANALYTIC EMPIRICAL APPROACH TO THE STUDY OF MEXICANS IN THE UNITED STATES IS PRESENTED. MEXICAN-AMERICANS FORM AN IMPORTANT ETHNIC GROUP BY VIRTUE OF NUMBERS, REGIONAL CONCENTRATION, SOCIAL POSITION, AND DYNAMIC CHARACTER. FINDINGS SHOULD BE AMENABLE TO COMPARATIVE TREATMENT WITH OTHER STATUS AND ETHNIC GROUPS. THE APPROACH INVOLVES A SERIES OF…

Gene flow in complex landscapes: Testing multiple hypotheses with causal modeling

Treesearch

Samuel A. Cushman; Kevin S. McKelvey; Jim Hayden; Michael K. Schwartz

2006-01-01

Predicting population-level effects of landscape change depends on identifying factors that influence population connectivity in complex landscapes. However, most putative movement corridors and barriers have not been based on empirical data. In this study, we identify factors that influence connectivity by comparing patterns of genetic similarity among 146 black bears...

Quality Assurance Policies and Practices in Scandinavian Higher Education Systems: Convergence or Different Paths?

ERIC Educational Resources Information Center

Kalpazidou Schmidt, Evanthia

2017-01-01

Because there is close cooperation on quality assurance in the Scandinavian countries, one would expect there to be convergence of quality assurance policies and practices in Scandinavian higher education. Few studies have analysed these quality assurance policies and practices from a comparative viewpoint. Based on empirical evidence produced in…

Assessing the Performance of Classical Test Theory Item Discrimination Estimators in Monte Carlo Simulations

ERIC Educational Resources Information Center

Bazaldua, Diego A. Luna; Lee, Young-Sun; Keller, Bryan; Fellers, Lauren

2017-01-01

The performance of various classical test theory (CTT) item discrimination estimators has been compared in the literature using both empirical and simulated data, resulting in mixed results regarding the preference of some discrimination estimators over others. This study analyzes the performance of various item discrimination estimators in CTT:…

Linking Class and Community: An Investigation of Service Learning

ERIC Educational Resources Information Center

Fleck, Bethany; Hussey, Heather D.; Rutledge-Ellison, Lily

2017-01-01

This study contributes to the service learning (SL) literature by providing new empirical evidence of learning from a problem-based SL research project conducted in a developmental research methods course. Two sections of the course taught in a traditional manner were compared to two sections of the course taught with an integrated SL project…

Some Empirical Evidence for Latent Trait Model Selection.

ERIC Educational Resources Information Center

Hutten, Leah R.

The results of this study suggest that for purposes of estimating ability by latent trait methods, the Rasch model compares favorably with the three-parameter logistic model. Using estimated parameters to make predictions about 25 actual number-correct score distributions with samples of 1,000 cases each, those predicted by the Rasch model fit the…

Flipped @ SBU: Student Satisfaction and the College Classroom

ERIC Educational Resources Information Center

Gross, Benjamin; Marinari, Maddalena; Hoffman, Mike; DeSimone, Kimberly; Burke, Peggy

2015-01-01

In this paper, the authors find empirical support for the effectiveness of the flipped classroom model. Using a quasi-experimental method, the authors compared students enrolled in flipped courses to their counterparts in more traditional lecture-based ones. A survey instrument was constructed to study how these two different groups of students…

An Empirical Study of Reentry Women.

ERIC Educational Resources Information Center

Pickering, Glenn S.; Galvin-Schaefers, Kate

1988-01-01

Compared 76 reentry working women with 78 career women. Found reentry women held lower-level jobs and scored lower on measures of assertiveness and autonomy than did career women. Reentry women did not score lower on self-esteem measures or dominance measures, and did not score higher than career women on either conflict or need for achievement…

Illiterate Prisoners? Myths and Empirical Realities

ERIC Educational Resources Information Center

Rankin, Carole E.

2005-01-01

This study reviews state and national surveys of prisoner literacy and compares their results to two recent surveys of literacy in Michigan prisoners. The persistent notion that prisoners are severely illiterate is shown to be a myth. In Michigan, only 10 to 11% of commitments were found to have Test of Adult Basic Education scores below grade…

Analysis of Institutionally Specific Retention Research: A Comparison between Survey and Institutional Database Methods

ERIC Educational Resources Information Center

Caison, Amy L.

2007-01-01

This study empirically explores the comparability of traditional survey-based retention research methodology with an alternative approach that relies on data commonly available in institutional student databases. Drawing on Tinto's [Tinto, V. (1993). "Leaving College: Rethinking the Causes and Cures of Student Attrition" (2nd Ed.), The University…

A Comparison of Behavioral and Constructivist Interventions for Increasing Math-Fact Fluency in a Second-Grade Classroom

ERIC Educational Resources Information Center

Poncy, Brian C.; McCallum, Elizabeth; Schmitt, Ara J.

2010-01-01

Although basic math skill deficits are commonly encountered across elementary and secondary school students, few empirically validated, group-administered interventions are available for educators attempting to prevent or remedy such problems. This study compared the effectiveness of two theoretically distinct interventions for improving the…

Does Bootstrap Procedure Provide Biased Estimates? An Empirical Examination for a Case of Multiple Regression.

ERIC Educational Resources Information Center

Fan, Xitao

This paper empirically and systematically assessed the performance of bootstrap resampling procedure as it was applied to a regression model. Parameter estimates from Monte Carlo experiments (repeated sampling from population) and bootstrap experiments (repeated resampling from one original bootstrap sample) were generated and compared. Sample…

Preequating with Empirical Item Characteristic Curves: An Observed-Score Preequating Method

ERIC Educational Resources Information Center

Zu, Jiyun; Puhan, Gautam

2014-01-01

Preequating is in demand because it reduces score reporting time. In this article, we evaluated an observed-score preequating method: the empirical item characteristic curve (EICC) method, which makes preequating without item response theory (IRT) possible. EICC preequating results were compared with a criterion equating and with IRT true-score…

A Comparison of Two Scoring Methods for an Automated Speech Scoring System

ERIC Educational Resources Information Center

Xi, Xiaoming; Higgins, Derrick; Zechner, Klaus; Williamson, David

2012-01-01

This paper compares two alternative scoring methods--multiple regression and classification trees--for an automated speech scoring system used in a practice environment. The two methods were evaluated on two criteria: construct representation and empirical performance in predicting human scores. The empirical performance of the two scoring models…

Detection of Person Misfit in Computerized Adaptive Tests with Polytomous Items.

ERIC Educational Resources Information Center

van Krimpen-Stoop, Edith M. L. A.; Meijer, Rob R.

2002-01-01

Compared the nominal and empirical null distributions of the standardized log-likelihood statistic for polytomous items for paper-and-pencil (P&P) and computerized adaptive tests (CATs). Results show that the empirical distribution of the statistic differed from the assumed standard normal distribution for both P&P tests and CATs. Also…

DEVELOPMENT OF NITROGEN LOADING - RESPONSE RELATIONSHIPS FOR ESTUARINE WATERS USING AN EMPIRICAL COMPARATIVE SYSTEMS APPROACH

EPA Science Inventory

The U.S. EPA Atlantic Ecology Division (AED) has initiated a multi-year research program to develop empirical nitrogen load-response models for embayments in southern New England. This is part of a multi-regional effort to develop nutrient load-response models for the Gulf of Mex...

Parenthood and Happiness: A Review of Folk Theories versus Empirical Evidence

ERIC Educational Resources Information Center

Hansen, Thomas

2012-01-01

This paper reviews and compares folk theories and empirical evidence about the influence of parenthood on happiness and life satisfaction. The review of attitudes toward parenthood and childlessness reveals that people tend to believe that parenthood is central to a meaningful and fulfilling life, and that the lives of childless people are…

Evaluating governance for sustainable development - Insights from experiences in the Dutch fen landscape.

PubMed

den Uyl, Roos M; Driessen, Peter P J

2015-11-01

Prominent strands of discussion in the literature on governance for sustainable development debate how change can be induced to enhance sustainability, and how to evaluate the interventions aimed at prompting such change. Strikingly, there are few contributions about how prominent ideas of inducing change deal with multiple governance criteria for pursuing sustainable development. Moreover, the way ideas about inducing change relate to criteria of governance for sustainable development is not yet studied in an empirical context. This paper therefore comparatively analyses how three prominent modes of sustainable development governance - adaptive management, transition management and payments for environmental services - relate to a set of five prominent criteria reported in the literature, namely: equity, democracy, legitimacy, the handling of scale issues and the handling of uncertainty issues. It finds that the academic debates on these three modes address these criteria with varying attention and rather fragmented, while in the empirical setting of the Dutch fen landscape several aspects relating to the studied criteria were present and substantially influenced the functioning of the three modes of sustainable development. Together, the analysis of the literature debate and the empirical data are able to show that a narrow evaluation perspective may fail to diagnose and capture relevant struggles and complexities coming along with governance for sustainable development relevant issues. The study shows that in order to advance our understanding of governance for sustainable development, it is indeed important to include multiple criteria in studying these modes. Moreover, the study shows the importance of including empirical experiences which manifest when different modes for sustainable development are applied in real-world settings. Copyright © 2015 Elsevier Ltd. All rights reserved.

Modeling the characteristics of wheel/rail rolling noise

NASA Astrophysics Data System (ADS)

Lui, Wai Keung; Li, Kai Ming; Frommer, Glenn H.

2005-04-01

To study the sound radiation characteristics of a passing train, four sets of noise measurements for different train operational conditions have been conducted at three different sites, including ballast tracks at grade and railway on a concrete viaduct. The time histories computed by the horizontal radiation models were compared with the measured noise profiles. The measured sound exposure levels are used to deduce the vertical directivity pattern for different railway systems. It is found that the vertical directivity of different railway systems shows a rather similar pattern. The vertical directivity of train noise is shown to increase up to about 30× before reducing to a minimum at 90×. A multipole expansion model is proposed to account for the vertical radiation directivity of the train noise. An empirical formula, which has been derived, compares well with the experimental data. The empirical model is found to be applicable to different train/rail systems at train speeds ranging up to 120 km/h in this study. [Work supported by MTR Corporation Ltd., Innovation Technology Commission of the HKSAR Government and The Hong Kong Polytechnic University.

Kinetic Plasma and Turbulent Mix Studies using DT Plastic-shell Implosions with Shell-thickness and Pressure Variations

NASA Astrophysics Data System (ADS)

Kim, Y.; Herrmann, H. W.; Hoffman, N. M.; Schmitt, M. J.; Bradley, P. A.; Kagan, G.; Gales, S.; Horsfield, C. J.; Rubery, M.; Leatherland, A.; Gatu Johnson, M.; Glebov, V.; Seka, W.; Marshall, F.; Stoeckl, C.; Church, J.

2014-10-01

Kinetic plasma and turbulent mix effects on inertial confinement fusion have been studied using a series of DT-filled plastic-shell implosions at the OMEGA laser facility. Plastic capsules of 4 different shell thicknesses (7.4, 15, 20, 29 micron) were shot at 2 different fill pressures in order to vary the ion mean free path compared to the size of fuel region (i.e., Knudsen number). We varied the empirical Knudsen number by a factor of 25. Measurements were obtained from the burn-averaged ion temperature and fuel areal density. Preliminary results indicate that as the empirical Knudsen number increases, fusion performances (e.g., neutron yield) increasingly deviate from hydrodynamic simulations unless turbulent mix and ion kinetic terms (e.g., enhanced ion diffusion, viscosity, thermal conduction, as well as Knudsen-layer fusion reactivity reduction) are considered. We are developing two separate simulations: one is a reduced-ion-kinetics model and the other is turbulent mix model. Two simulation results will be compared with the experimental observables.

Cost-effectiveness of ceftolozane/tazobactam plus metronidazole versus piperacillin/tazobactam as initial empiric therapy for the treatment of complicated intra-abdominal infections based on pathogen distributions drawn from national surveillance data in the United States.

PubMed

Prabhu, Vimalanand S; Solomkin, Joseph S; Medic, Goran; Foo, Jason; Borse, Rebekah H; Kauf, Teresa; Miller, Benjamin; Sen, Shuvayu S; Basu, Anirban

2017-01-01

The prevalence of antimicrobial resistance among gram-negative pathogens in complicated intra-abdominal infections (cIAIs) has increased. In the absence of timely information on the infecting pathogens and their susceptibilities, local or regional epidemiology may guide initial empirical therapy and reduce treatment failure, length of stay and mortality. The objective of this study was to assess the cost-effectiveness of ceftolozane/tazobactam + metronidazole compared with piperacillin/tazobactam in the treatment of hospitalized US patients with cIAI at risk of infection with resistant pathogens. We used a decision-analytic Monte Carlo simulation model to compare the costs and quality-adjusted life years (QALYs) of persons infected with nosocomial gram-negative cIAI treated empirically with either ceftolozane/tazobactam + metronidazole or piperacillin/tazobactam. Pathogen isolates were randomly drawn from the Program to Assess Ceftolozane/Tazobactam Susceptibility (PACTS) database, a surveillance database of non-duplicate bacterial isolates collected from patients with cIAIs in medical centers in the USA from 2011 to 2013. Susceptibility to initial therapy was based on the measured susceptibilities reported in the PACTS database determined using standard broth micro-dilution methods as described by the Clinical and Laboratory Standards Institute (CLSI). Our model results, with baseline resistance levels from the PACTS database, indicated that ceftolozane/tazobactam + metronidazole dominated piperacillin/tazobactam, with lower costs ($44,226/patient vs. $44,811/patient respectively) and higher QALYs (12.85/patient vs. 12.70/patient, respectively). Ceftolozane/tazobactam + metronidazole remained the dominant choice in one-way and probabilistic sensitivity analyses. Based on surveillance data, ceftolozane/tazobactam is more likely to be an appropriate empiric therapy for cIAI in the US. Results from a decision-analytic simulation model indicate that use of ceftolozane/tazobactam + metronidazole would result in cost savings and improves QALYs, compared with piperacillin/tazobactam.

IB-LBM study on cell sorting by pinched flow fractionation.

PubMed

Ma, Jingtao; Xu, Yuanqing; Tian, Fangbao; Tang, Xiaoying

2014-01-01

Separation of two categories of cells in pinched flow fractionation(PFF) device is simulated by employing IB-LBM. The separation performances at low Reynolds number (about 1) under different pinched segment widths, flow ratios, cell features, and distances between neighboring cells are studied and the results are compared with those predicted by the empirical formula. The simulation indicates that the diluent flow rate should approximate to or more than the flow rate of particle solution in order to get a relatively ideal separation performance. The discrepancy of outflow position between numerical simulation and the empirical prediction enlarges, when the cells become more flexible. Too short distance between two neighboring cells could lead to cell banding which would result in incomplete separation, and the relative position of two neighboring cells influences the banding of cells. The present study will probably provide some new applications of PFF, and make some suggestions on the design of PFF devices.

Comparison among cognitive diagnostic models for the TIMSS 2007 fourth grade mathematics assessment.

PubMed

Yamaguchi, Kazuhiro; Okada, Kensuke

2018-01-01

A variety of cognitive diagnostic models (CDMs) have been developed in recent years to help with the diagnostic assessment and evaluation of students. Each model makes different assumptions about the relationship between students' achievement and skills, which makes it important to empirically investigate which CDMs better fit the actual data. In this study, we examined this question by comparatively fitting representative CDMs to the Trends in International Mathematics and Science Study (TIMSS) 2007 assessment data across seven countries. The following two major findings emerged. First, in accordance with former studies, CDMs had a better fit than did the item response theory models. Second, main effects models generally had a better fit than other parsimonious or the saturated models. Related to the second finding, the fit of the traditional parsimonious models such as the DINA and DINO models were not optimal. The empirical educational implications of these findings are discussed.

Measurement and comparison of nursing faculty members' critical thinking skills.

PubMed

Blondy, Laurie C

2011-03-01

Nursing faculty members strive to teach students to think critically. It has long been assumed that nursing faculty members are good at critical thinking because they are expected to teach these skills to students, but this assumption has not been well supported empirically. Faculty members question their ability to think critically and are unsure of their skills. The purpose of this study was to address this assumption by measuring nursing faculty members' critical thinking skills and compare the faculty mean score to that of a student norming group, and to the mean scores of other nursing faculty studies. Findings can be used to increase nursing faculty members' understanding of their critical thinking skills, prompt discussion about critical thinking skills, and to help faculty members address concerns and uncertainty about the concept of critical thinking. This study also helps establish an empirical basis for future research.

Comparison among cognitive diagnostic models for the TIMSS 2007 fourth grade mathematics assessment

PubMed Central

Okada, Kensuke

2018-01-01

A variety of cognitive diagnostic models (CDMs) have been developed in recent years to help with the diagnostic assessment and evaluation of students. Each model makes different assumptions about the relationship between students’ achievement and skills, which makes it important to empirically investigate which CDMs better fit the actual data. In this study, we examined this question by comparatively fitting representative CDMs to the Trends in International Mathematics and Science Study (TIMSS) 2007 assessment data across seven countries. The following two major findings emerged. First, in accordance with former studies, CDMs had a better fit than did the item response theory models. Second, main effects models generally had a better fit than other parsimonious or the saturated models. Related to the second finding, the fit of the traditional parsimonious models such as the DINA and DINO models were not optimal. The empirical educational implications of these findings are discussed. PMID:29394257

Empirical method to measure stochasticity and multifractality in nonlinear time series

NASA Astrophysics Data System (ADS)

Lin, Chih-Hao; Chang, Chia-Seng; Li, Sai-Ping

2013-12-01

An empirical algorithm is used here to study the stochastic and multifractal nature of nonlinear time series. A parameter can be defined to quantitatively measure the deviation of the time series from a Wiener process so that the stochasticity of different time series can be compared. The local volatility of the time series under study can be constructed using this algorithm, and the multifractal structure of the time series can be analyzed by using this local volatility. As an example, we employ this method to analyze financial time series from different stock markets. The result shows that while developed markets evolve very much like an Ito process, the emergent markets are far from efficient. Differences about the multifractal structures and leverage effects between developed and emergent markets are discussed. The algorithm used here can be applied in a similar fashion to study time series of other complex systems.

Rate My Sleep: Examining the Information, Function, and Basis in Empirical Evidence Within Sleep Applications for Mobile Devices.

PubMed

Lee-Tobin, Peta A; Ogeil, Rowan P; Savic, Michael; Lubman, Dan I

2017-11-15

Sleep applications (apps) have proliferated in online spaces, but few studies have examined the validity of the information contained within the apps. This study aimed to examine the information and functions found within sleep apps, determine if the information is based on empirical evidence, and whether or not user ratings were affected by these factors. Sleep apps found in the Google Play store (n = 76) were coded using content analysis to examine the types of information, functions, and evidence base of each app. Only 32.9% of sleep apps contained empirical evidence supporting their claims, 15.8% contained clinical input, and 13.2% contained links to sleep literature. Apps also contained information on how sleep is affected by alcohol or drugs (23.7%), food (13.2%), daily activities (13.2), and stress (13.2%). A mean difference in average user rating was found between apps that contained at least one source of information compared those that did not. App user ratings were not associated with an app having multiple functions, or from an app drawing on multiple sources of evidence (except for sleep literature only). Last, there was a higher average user rating among apps that contained a sleep tip function. Sleep apps are increasingly popular, demonstrated by the large number of downloads in the Google Play store. Users favored apps that contained sleep tips; however, these tips and other information in the apps were generally not based on empirical evidence. Future research in the area of sleep apps should consider constructing sleep apps derived from empirical evidence and examining their effectiveness. © 2017 American Academy of Sleep Medicine

A Comparative GLOBE Study: Regional Differences in Cultural Values, Cultural Practices and Perspectives of Leadership between Research Administrators in the United States, Europe and Australasia

ERIC Educational Resources Information Center

Sablatura, Martha Trevino

2012-01-01

The (GLOBE) Global Leadership and Organizational Behavior Effectiveness Study (House, Gupta, Hanges, Javidan, and Dorfman, 2004), introduced the concept of leadership across cultures and, along with other empirical research, has shown that the status and influence of leadership vary considerably as a result of the cultural forces in different…

A Comparative Study of a Team Vs. a Non-Team Teaching Approach in High School Biology.

ERIC Educational Resources Information Center

Monaco, William J.; Szabo, Michael

The purpose of this study was to obtain empirical data for the evaluation of a team approach for teaching biology. A sample of 147 sophomore students was divided into six sections; each section was randomly assigned as control or treatment. The team consisted of three instructors. Each member taught a control group for an entire year. After an…

The Face of Digital Literacy for Muslim Teenage Girls: A Comparative Study of Bradford Muslim Girl Schools

ERIC Educational Resources Information Center

Iqbal, Javed; Hardaker, Glenn; Sabki, Aishah Ahmad; Elbeltagi, Ibrahim

2014-01-01

This paper is grounded in a qualitative approach, to call forth the views of Muslim teenage girls on their access and use of learning technologies for inclusive educational practice. The 45 Muslim teenage girls, aged 14-19 years old, from three British Muslim girls schools participated in this empirical study. Semi-structured interviews were used…

Returns to Education in the Economic Transition: A Systematic Assessment Using Comparable Data

ERIC Educational Resources Information Center

Flabbi, Luca; Paternostro, Stefano; Tiongson, Erwin R.

2008-01-01

This paper studies a sample of economies in transition to verify the assertion that returns to schooling increase as an economy transitions to a market environment. This claim has been difficult to assess in the past as the empirical evidence so far has covered only a few countries over short time periods. A number of studies find that returns to…

A Closer Look at the Output Hypothesis: The Effect of Pushed Output on Noticing and Inductive Learning of the Spanish Future Tense

ERIC Educational Resources Information Center

Russell, Victoria

2014-01-01

This study empirically tested the noticing function of the output hypothesis (Swain, 1993, 1995, 1998) and explored the relationship between noticing and learning by comparing the effects of the production of output to exposure to textually enhanced input. The present study is a conceptual replication of Izumi (2002); however, Izumi examined a…

Cognitive Processes in Folk Ornithology: The Identification of Gulls. Working Papers of the Language Behavior Research Laboratory, No. 42.

ERIC Educational Resources Information Center

Hunn, Eugene

Recent studies of folk biology clearly reveal the detailed empirical knowledge of living things which is an important and characteristic element of pre-scientific cultures. This paper attempts a contribution to the study of such systems of knowledge by analyzing the comparable skills of a few American birdwatchers. The process of identification of…

Impact of Initiatives to Implement Science Inquiry: A Comparative Study of the Turkish, Israeli, Swedish and Czech Science Education Systems

ERIC Educational Resources Information Center

Heinz, Jana; Enghag, Margareta; Stuchlikova, Iva; Cakmakci, Gultekin; Peleg, Ran; Baram-Tsabari, Ayelet

2017-01-01

This empirical study investigates factors that influence the implementation of science inquiry in the education systems of Turkey, Israel, Sweden and the Czech Republic. Data was collected by means of recordings of science experts' discussions as part of an EU-funded project called Science-Teacher Education Advanced Methods (2009-2012). Results of…

A Regression Analysis of South Carolina Algebra I End-of-Course Exam Scores by Schedule Type

ERIC Educational Resources Information Center

Smith, Dawn M.

2017-01-01

The purpose of this study was to examine the relationship between scheduling and first-year-high-school students' exam scores on the South Carolina Algebra I End-of-Course (EOC) assessment. The study compared existing empirical data from two southeastern high schools from the same school district using 4 X 4 block schedules from 2011-2014 and…

The Elegance of Disordered Granular Packings: A Validation of Edwards' Hypothesis

NASA Technical Reports Server (NTRS)

Metzger, Philip T.; Donahue, Carly M.

2004-01-01

We have found a way to analyze Edwards' density of states for static granular packings in the special case of round, rigid, frictionless grains assuming constant coordination number. It obtains the most entropic density of single grain states, which predicts several observables including the distribution of contact forces. We compare these results against empirical data obtained in dynamic simulations of granular packings. The agreement between theory and the empirics is quite good, helping validate the use of statistical mechanics methods in granular physics. The differences between theory and empirics are mainly due to the variable coordination number, and when the empirical data are sorted by that number we obtain several insights that suggest an underlying elegance in the density of states

Sensitivity Analysis of Empirical Results on Civil War Onset

ERIC Educational Resources Information Center

Hegre, Havard; Sambanis, Nicholas

2006-01-01

In the literature on civil war onset, several empirical results are not robust or replicable across studies. Studies use different definitions of civil war and analyze different time periods, so readers cannot easily determine if differences in empirical results are due to those factors or if most empirical results are just not robust. The authors…

Nonparametric spirometry reference values for Hispanic Americans.

PubMed

Glenn, Nancy L; Brown, Vanessa M

2011-02-01

Recent literature sites ethnic origin as a major factor in developing pulmonary function reference values. Extensive studies established reference values for European and African Americans, but not for Hispanic Americans. The Third National Health and Nutrition Examination Survey defines Hispanic as individuals of Spanish speaking cultures. While no group was excluded from the target population, sample size requirements only allowed inclusion of individuals who identified themselves as Mexican Americans. This research constructs nonparametric reference value confidence intervals for Hispanic American pulmonary function. The method is applicable to all ethnicities. We use empirical likelihood confidence intervals to establish normal ranges for reference values. Its major advantage: it is model free, but shares asymptotic properties of model based methods. Statistical comparisons indicate that empirical likelihood interval lengths are comparable to normal theory intervals. Power and efficiency studies agree with previously published theoretical results.

The active comparator, new user study design in pharmacoepidemiology: historical foundations and contemporary application

PubMed Central

Lund, Jennifer L.; Richardson, David B.; Stürmer, Til

2016-01-01

Better understanding of biases related to selective prescribing of, and adherence to, preventive treatments has led to improvements in the design and analysis of pharmacoepidemiologic studies. One influential development has been the “active comparator, new user” study design, which seeks to emulate the design of a head-to-head randomized controlled trial. In this review, we first discuss biases that may affect pharmacoepidemiologic studies and describe their direction and magnitude in a variety of settings. We then present the historical foundations of the active comparator, new user study design and explain how this design conceptually mitigates biases leading to a paradigm shift in pharmacoepidemiology. We offer practical guidance on the implementation of the study design using administrative databases. Finally, we provide an empirical example in which the active comparator, new user study design addresses biases that have previously impeded pharmacoepidemiologic studies. PMID:26954351

Empirical Tryout of a New Statistic for Detecting Temporally Inconsistent Responders.

PubMed

Kerry, Matthew J

2018-01-01

Statistical screening of self-report data is often advised to support the quality of analyzed responses - For example, reduction of insufficient effort responding (IER). One recently introduced index based on Mahalanobis's D for detecting outliers in cross-sectional designs replaces centered scores with difference scores between repeated-measure items: Termed person temporal consistency ( D 2 ptc ). Although the adapted D 2 ptc index demonstrated usefulness in simulation datasets, it has not been applied to empirical data. The current study addresses D 2 ptc 's low uptake by critically appraising its performance across three empirical applications. Independent samples were selected to represent a range of scenarios commonly encountered by organizational researchers. First, in Sample 1, a repeat-measure of future time perspective (FTP) inexperienced working adults (age >40-years; n = 620) indicated that temporal inconsistency was significantly related to respondent age and item reverse-scoring. Second, in repeat-measure of team efficacy aggregations, D 2 ptc successfully detected team-level inconsistency across repeat-performance cycles. Thirdly, the usefulness of the D 2 ptc was examined in an experimental study dataset of subjective life expectancy indicated significantly more stable responding in experimental conditions compared to controls. The empirical findings support D 2 ptc 's flexible and useful application to distinct study designs. Discussion centers on current limitations and further extensions that may be of value to psychologists screening self-report data for strengthening response quality and meaningfulness of inferences from repeated-measures self-reports. Taken together, the findings support the usefulness of the newly devised statistic for detecting IER and other extreme response patterns.

Secondary use of empirical research data in medical ethics papers on gamete donation: forms of use and pitfalls.

PubMed

Provoost, Veerle

2015-03-01

This paper aims to provide a description of how authors publishing in medical ethics journals have made use of empirical research data in papers on the topic of gamete or embryo donation by means of references to studies conducted by others (secondary use). Rather than making a direct contribution to the theoretical methodological literature about the role empirical research data could play or should play in ethics studies, the focus is on the particular uses of these data and the problems that can be encountered with this use. In the selection of papers examined, apart from being used to describe the context, empirical evidence was mainly used to recount problems that needed solving. Few of the authors looked critically at the quality of the studies they quoted, and several instances were found of empirical data being used poorly or inappropriately. This study provides some initial baseline evidence that shows empirical data, in the form of references to studies, are sometimes being used in inappropriate ways. This suggests that medical ethicists should be more concerned about the quality of the empirical data selected, the appropriateness of the choice for a particular type of data (from a particular type of study) and the correct integration of this evidence in sound argumentation. Given that empirical data can be misused also when merely cited instead of reported, it may be worthwhile to explore good practice requirements for this type of use of empirical data in medical ethics.

Targeting premeal anxiety in eating disordered clients and normal controls: a preliminary investigation into the use of mindful eating vs. distraction during food exposure.

PubMed

Marek, Ryan J; Ben-Porath, Denise D; Federici, Anita; Wisniewski, Lucene; Warren, Mark

2013-09-01

Studies have demonstrated that negative affect increases prior to food intake in individuals diagnosed with an eating disorder. Mindfulness has been supported empirically to treat experiential avoidance stemming from anxiety. Thus, the current objective in this study is to empirically compare mindfulness vs. thought suppression invention during a food exposure in both clinical and nonclinical samples. In a 2 (Group: clinical vs. nonclinical) × 2 (INTERVENTION: mindfulness vs. distraction) counterbalanced within treatment design, the current investigation sought to determine the differential effectiveness of a brief mindfulness intervention vs. a brief distraction intervention in women diagnosed with AN and BN in a clinical and nonclinical sample during a food exposure. Results indicated that the eating disorder group reported a significant increase in negative affect after the mindfulness intervention as compared to the distraction intervention, whereas the nonclinical group reported a significant decrease in negative affect after the mindfulness intervention as compared to the distraction intervention. Preliminary findings suggest that clinicians may want to proceed cautiously when using mindful eating in those with severe eating disorders during the early stages of food exposure. Limitations and future directions are discussed. Copyright © 2013 Wiley Periodicals, Inc.

Perceptions of Why Women Stay in Physically Abusive Relationships: A Comparative Study of Chinese and U.S. College Students.

PubMed

Pugh, Brandie; Li, Luye; Sun, Ivan Y

2018-05-01

In both China and the United States, public attitudes toward intimate partner violence (IPV) have shifted from viewing IPV as a tolerable, private matter to viewing it as a matter of public concern that should be dealt with as a crime. Empirical and comparative examinations of the perceptions of why women stay in physically abusive relationships are lacking. Answering this question calls for comprehensive, methodologically rigorous research. Using survey data collected from approximately 1,000 college students from two Chinese and two U.S. universities, this study empirically compared and contrasted factors that impact U.S. and Chinese students' perceptions as to why women remain in physically abusive relationships. Utilizing a theoretical framework of social constructionism, two common reasons were assessed: Women stay in physically abusive relationships because of learned helplessness and positive beliefs in the relationship/hope for the future. The results show that viewing IPV as a crime, gender, and beliefs of the causes of IPV were robust predictors of college students' perceptions toward why women stay in physically abusive relationships. U.S. college students were more likely to express sympathy and understanding toward why women remain in abusive relationships than Chinese students. Directions for future research and policy implications were discussed.

Petrophysical approach for S-wave velocity prediction based on brittleness index and total organic carbon of shale gas reservoir: A case study from Horn River Basin, Canada

NASA Astrophysics Data System (ADS)

Kim, Taeyoun; Hwang, Seho; Jang, Seonghyung

2017-01-01

When finding the "sweet spot" of a shale gas reservoir, it is essential to estimate the brittleness index (BI) and total organic carbon (TOC) of the formation. Particularly, the BI is one of the key factors in determining the crack propagation and crushing efficiency for hydraulic fracturing. There are several methods for estimating the BI of a formation, but most of them are empirical equations that are specific to particular rock types. We estimated the mineralogical BI based on elemental capture spectroscopy (ECS) log and elastic BI based on well log data, and we propose a new method for predicting S-wave velocity (VS) using mineralogical BI and elastic BI. The TOC is related to the gas content of shale gas reservoirs. Since it is difficult to perform core analysis for all intervals of shale gas reservoirs, we make empirical equations for the Horn River Basin, Canada, as well as TOC log using a linear relation between core-tested TOC and well log data. In addition, two empirical equations have been suggested for VS prediction based on density and gamma ray log used for TOC analysis. By applying the empirical equations proposed from the perspective of BI and TOC to another well log data and then comparing predicted VS log with real VS log, the validity of empirical equations suggested in this paper has been tested.

Empirically evaluating decision-analytic models.

PubMed

Goldhaber-Fiebert, Jeremy D; Stout, Natasha K; Goldie, Sue J

2010-08-01

Model-based cost-effectiveness analyses support decision-making. To augment model credibility, evaluation via comparison to independent, empirical studies is recommended. We developed a structured reporting format for model evaluation and conducted a structured literature review to characterize current model evaluation recommendations and practices. As an illustration, we applied the reporting format to evaluate a microsimulation of human papillomavirus and cervical cancer. The model's outputs and uncertainty ranges were compared with multiple outcomes from a study of long-term progression from high-grade precancer (cervical intraepithelial neoplasia [CIN]) to cancer. Outcomes included 5 to 30-year cumulative cancer risk among women with and without appropriate CIN treatment. Consistency was measured by model ranges overlapping study confidence intervals. The structured reporting format included: matching baseline characteristics and follow-up, reporting model and study uncertainty, and stating metrics of consistency for model and study results. Structured searches yielded 2963 articles with 67 meeting inclusion criteria and found variation in how current model evaluations are reported. Evaluation of the cervical cancer microsimulation, reported using the proposed format, showed a modeled cumulative risk of invasive cancer for inadequately treated women of 39.6% (30.9-49.7) at 30 years, compared with the study: 37.5% (28.4-48.3). For appropriately treated women, modeled risks were 1.0% (0.7-1.3) at 30 years, study: 1.5% (0.4-3.3). To support external and projective validity, cost-effectiveness models should be iteratively evaluated as new studies become available, with reporting standardized to facilitate assessment. Such evaluations are particularly relevant for models used to conduct comparative effectiveness analyses.

Resettling the Thoughts of Ernst Mach and the Vienna Circle in Europe: The Cases of Finland and Germany

NASA Astrophysics Data System (ADS)

Siemsen, Hayo; Siemsen, Karl Hayo

2009-04-01

Although it is generally assumed that the thoughts of Ernst Mach and the scientific fields he influenced (in this case psychophysics and Gestalt psychology) emigrated from Europe during Second World War they apparently survived in Finland, influencing the Finnish education system. The following article evaluates this relationship and its implications from a historical and an empirical perspective. In empirical studies comparing the education systems of different countries, such as PISA, the Finns are in general regarded as being very successful with their school system. Does this apparent success have anything to do with a Machian influence? Our current research has so far revealed that the Finns have gone through an independent cultural development in two specific aspects: in the idea of the development of the individual personality (Snellman) and in a specific phenomenalism (developed primarily by Eino Kaila, in which Kaila was heavily influenced in this by Ernst Mach). The result can be regarded as a nation-wide “Experiment”, the empirical evaluation of which can be found partly in the statistics of the PISA Studies, especially the evaluation of Finland in relation to other countries.

Assessment of collaborative problem solving skills in Undergraduate Medical Students at Ziauddin College of Medicine, Karachi

PubMed Central

Mughal, Arsalan Manzoor; Shaikh, Sirajul Haque

2018-01-01

Objective: Collaborative Problem Solving Empirical Progressions from the Assessment and Teaching of 21st Century Skills (ATC21S) framework were used to determine the level of collaborative problem solving skills (CPS) in first, second and third year MBBS students at Ziauddin College of Medicine during Problem-Based Learning (PBL) sessions. Variations based on gender and roles were studied. Methods: It is an analytical comparative cross-sectional study in which seven PBL groups were selected per year by non-probability convenient sampling. Data was collected using the Collaborative Problem Solving Five Strands Empirical Progressions by the primary investigator through observation of the students during PBL sessions. Duration of study was six months. Results: We found that in our students, development of social dimension skills is facilitated to a greater extent than the development of cognitive dimension skills through the process of PBL. These skills are generally better developed in the leader compared to the scribe and members in a group. They are also more developed in females compared to males. Modification in them is also observed as the year's progress. Conclusion: Although PBLs facilitate development of CPS skills' progression however in our curriculum, PBLs mainly focus on social skills development and have less emphasis on cognitive skill development. Thus, hybrid instructional strategies with components from TBL and mentorship are recommended for better development of CPS skills. PMID:29643904

Assessment of collaborative problem solving skills in Undergraduate Medical Students at Ziauddin College of Medicine, Karachi.

PubMed

Mughal, Arsalan Manzoor; Shaikh, Sirajul Haque

2018-01-01

Collaborative Problem Solving Empirical Progressions from the Assessment and Teaching of 21st Century Skills (ATC21S) framework were used to determine the level of collaborative problem solving skills (CPS) in first, second and third year MBBS students at Ziauddin College of Medicine during Problem-Based Learning (PBL) sessions. Variations based on gender and roles were studied. It is an analytical comparative cross-sectional study in which seven PBL groups were selected per year by non-probability convenient sampling. Data was collected using the Collaborative Problem Solving Five Strands Empirical Progressions by the primary investigator through observation of the students during PBL sessions. Duration of study was six months. We found that in our students, development of social dimension skills is facilitated to a greater extent than the development of cognitive dimension skills through the process of PBL. These skills are generally better developed in the leader compared to the scribe and members in a group. They are also more developed in females compared to males. Modification in them is also observed as the year's progress. Although PBLs facilitate development of CPS skills' progression however in our curriculum, PBLs mainly focus on social skills development and have less emphasis on cognitive skill development. Thus, hybrid instructional strategies with components from TBL and mentorship are recommended for better development of CPS skills.

Genetic testing in patients with acute coronary syndrome undergoing percutaneous coronary intervention: a cost-effectiveness analysis.

PubMed

Lala, A; Berger, J S; Sharma, G; Hochman, J S; Scott Braithwaite, R; Ladapo, J A

2013-01-01

The CYP2C19 genotype is a predictor of adverse cardiovascular events in acute coronary syndrome (ACS) patients undergoing percutaneous coronary intervention (PCI) treated with clopidogrel. We aimed to evaluate the cost-effectiveness of a CYP2C19*2 genotype-guided strategy of antiplatelet therapy in ACS patients undergoing PCI, compared with two 'no testing' strategies (empiric clopidogrel or prasugrel). We developed a Markov model to compare three strategies. The model captured adverse cardiovascular events and antiplatelet-related complications. Costs were expressed in 2010 US dollars and estimated using diagnosis-related group codes and Medicare reimbursement rates. The net wholesale price for prasugrel was estimated as $5.45 per day. A generic estimate for clopidogrel of $1.00 per day was used and genetic testing was assumed to cost $500. Base case analyses demonstrated little difference between treatment strategies. The genetic testing-guided strategy yielded the most QALYs and was the least costly. Over 15 months, total costs were $18 lower with a gain of 0.004 QALY in the genotype-guided strategy compared with empiric clopidogrel, and $899 lower with a gain of 0.0005 QALY compared with empiric prasugrel. The strongest predictor of the preferred strategy was the relative risk of thrombotic events in carriers compared with wild-type individuals treated with clopidogrel. Above a 47% increased risk, a genotype-guided strategy was the dominant strategy. Above a clopidogrel cost of $3.96 per day, genetic testing was no longer dominant but remained cost-effective. Among ACS patients undergoing PCI, a genotype-guided strategy yields similar outcomes to empiric approaches to treatment, but is marginally less costly and more effective. © 2012 International Society on Thrombosis and Haemostasis.

Predictive vs. Empiric Assessment of Schistosomiasis: Implications for Treatment Projections in Ghana

PubMed Central

Kabore, Achille; Biritwum, Nana-Kwadwo; Downs, Philip W.; Soares Magalhaes, Ricardo J.; Zhang, Yaobi; Ottesen, Eric A.

2013-01-01

Background Mapping the distribution of schistosomiasis is essential to determine where control programs should operate, but because it is impractical to assess infection prevalence in every potentially endemic community, model-based geostatistics (MBG) is increasingly being used to predict prevalence and determine intervention strategies. Methodology/Principal Findings To assess the accuracy of MBG predictions for Schistosoma haematobium infection in Ghana, school surveys were evaluated at 79 sites to yield empiric prevalence values that could be compared with values derived from recently published MBG predictions. Based on these findings schools were categorized according to WHO guidelines so that practical implications of any differences could be determined. Using the mean predicted values alone, 21 of the 25 empirically determined ‘high-risk’ schools requiring yearly praziquantel would have been undertreated and almost 20% of the remaining schools would have been treated despite empirically-determined absence of infection – translating into 28% of the children in the 79 schools being undertreated and 12% receiving treatment in the absence of any demonstrated need. Conclusions/Significance Using the current predictive map for Ghana as a spatial decision support tool by aggregating prevalence estimates to the district level was clearly not adequate for guiding the national program, but the alternative of assessing each school in potentially endemic areas of Ghana or elsewhere is not at all feasible; modelling must be a tool complementary to empiric assessments. Thus for practical usefulness, predictive risk mapping should not be thought of as a one-time exercise but must, as in the current study, be an iterative process that incorporates empiric testing and model refining to create updated versions that meet the needs of disease control operational managers. PMID:23505584

GPP in Loblolly Pine: A Monthly Comparison of Empirical and Process Models

Treesearch

Christopher Gough; John Seiler; Kurt Johnsen; David Arthur Sampson

2002-01-01

Monthly and yearly gross primary productivity (GPP) estimates derived from an empirical and two process based models (3PG and BIOMASS) were compared. Spatial and temporal variation in foliar gas photosynthesis was examined and used to develop GPP prediction models for fertilized nine-year-old loblolly pine (Pinus taeda) stands located in the North...

Trends in Research Methods in Applied Linguistics: China and the West.

ERIC Educational Resources Information Center

Yihong, Gao; Lichun, Li; Jun, Lu

2001-01-01

Examines and compares current trends in applied linguistics (AL) research methods in China and the West. Reviews AL articles in four Chinese journals, from 1978-1997, and four English journals from 1985 to 1997. Articles are categorized and subcategorized. Results show that in China, AL research is heading from non-empirical toward empirical, with…

Empirical Determination of Effectiveness of a Competency Based Program in Distributive Education. Final Report.

ERIC Educational Resources Information Center

Charters, Margaret; And Others

The primary objective of the Syracuse project was to make an empirical determination of the effectiveness of a competency-based (CB) distributive education program by comparing student achievement in three of its major components with similar traditionally organized courses at Syracuse, Buffalo, and Baruch. The three components were retailing,…

An Empirical Model for the Use of Biglan's Disciplinary Categories. AIR Forum 1979 Paper.

ERIC Educational Resources Information Center

Muffo, John A.; Langston, Ira W., IV

The Biglan method of grouping academic disciplines for comparative purposes is discussed as well as an empirically-based system for making internal comparisons among different academic units. The clusters of disciplines developed by Biglan (pure and applied, soft and hard, life and nonlife) are useful guides in working with data involving…

Oracle or Monacle: Research Concerning Attitudes Toward Feminism.

ERIC Educational Resources Information Center

Prescott, Suzanne; Schmid, Margaret

Both popular studies and more serious empirical studies of attitudes toward feminism are reviewed beginning with Clifford Kirkpatrick's early empirical work and including the more recent empirical studies completed since 1970. The review examines the contents of items used to measure feminism, and the methodology and sampling used in studies, as…

Bacteria causing bacteremia in pediatric cancer patients presenting with febrile neutropenia--species distribution and susceptibility patterns.

PubMed

Miedema, Karin G E; Winter, Rik H L J; Ammann, Roland A; Droz, Sara; Spanjaard, Lodewijk; de Bont, Eveline S J M; Kamps, Willem A; van de Wetering, Marianne D; Tissing, Wim J E

2013-09-01

Infections are a major cause of morbidity and mortality in pediatric cancer patients. The aim of this study was to establish the microbiological spectrum and the susceptibility patterns of bacteremia-causing bacteria in pediatric cancer patients with febrile neutropenia in relation to the use of prophylactic and empirical antibiotics. We analyzed positive blood cultures of pediatric cancer patients presenting with febrile neutropenia between 2004 and 2011 in Groningen and Amsterdam (the Netherlands) and in Bern (Switzerland), using different antibiotic prophylactic and empirical regimens. A total of 156 patients with 202 bacteremias, due to 248 bacteria species, were enrolled. The majority (73%) of bacteremias were caused by Gram-positive bacteria. Gram-negative bacteria, especially Pseudomonas aeruginosa, were observed significantly more often in Bern, where no fluoroquinolone prophylaxis was used. Ciprofloxacin-resistant bacteria were cultured more often from patients who did receive ciprofloxacin prophylaxis, compared to the patients who did not (57 versus 11%, p = 0.044). Gram-positive bacteria predominated in this study. We showed that the use of prophylactic antibiotics in pediatric cancer patients was associated with increased resistance rates, which needs further study. The strategy for empiric antimicrobial therapy for febrile neutropenia should be adapted to local antibiotic resistance patterns.

Disease Risk Score (DRS) as a Confounder Summary Method: Systematic Review and Recommendations

PubMed Central

Tadrous, Mina; Gagne, Joshua J.; Stürmer, Til; Cadarette, Suzanne M.

2013-01-01

Purpose To systematically examine trends and applications of the disease risk score (DRS) as a confounder summary method. Methods We completed a systematic search of MEDLINE and Web of Science® to identify all English language articles that applied DRS methods. We tabulated the number of publications by year and type (empirical application, methodological contribution, or review paper) and summarized methods used in empirical applications overall and by publication year (<2000, ≥2000). Results Of 714 unique articles identified, 97 examined DRS methods and 86 were empirical applications. We observed a bimodal distribution in the number of publications over time, with a peak 1979-1980, and resurgence since 2000. The majority of applications with methodological detail derived DRS using logistic regression (47%), used DRS as a categorical variable in regression (93%), and applied DRS in a non-experimental cohort (47%) or case-control (42%) study. Few studies examined effect modification by outcome risk (23%). Conclusion Use of DRS methods has increased yet remains low. Comparative effectiveness research may benefit from more DRS applications, particularly to examine effect modification by outcome risk. Standardized terminology may facilitate identification, application, and comprehension of DRS methods. More research is needed to support the application of DRS methods, particularly in case-control studies. PMID:23172692

Disease risk score as a confounder summary method: systematic review and recommendations.

PubMed

Tadrous, Mina; Gagne, Joshua J; Stürmer, Til; Cadarette, Suzanne M

2013-02-01

To systematically examine trends and applications of the disease risk score (DRS) as a confounder summary method. We completed a systematic search of MEDLINE and Web of Science® to identify all English language articles that applied DRS methods. We tabulated the number of publications by year and type (empirical application, methodological contribution, or review paper) and summarized methods used in empirical applications overall and by publication year (<2000, ≥2000). Of 714 unique articles identified, 97 examined DRS methods and 86 were empirical applications. We observed a bimodal distribution in the number of publications over time, with a peak 1979-1980, and resurgence since 2000. The majority of applications with methodological detail derived DRS using logistic regression (47%), used DRS as a categorical variable in regression (93%), and applied DRS in a non-experimental cohort (47%) or case-control (42%) study. Few studies examined effect modification by outcome risk (23%). Use of DRS methods has increased yet remains low. Comparative effectiveness research may benefit from more DRS applications, particularly to examine effect modification by outcome risk. Standardized terminology may facilitate identification, application, and comprehension of DRS methods. More research is needed to support the application of DRS methods, particularly in case-control studies. Copyright © 2012 John Wiley & Sons, Ltd.

Genetic drift and collective dispersal can result in chaotic genetic patchiness.

PubMed

Broquet, Thomas; Viard, Frédérique; Yearsley, Jonathan M

2013-06-01

Chaotic genetic patchiness denotes unexpected patterns of genetic differentiation that are observed at a fine scale and are not stable in time. These patterns have been described in marine species with free-living larvae, but are unexpected because they occur at a scale below the dispersal range of pelagic larvae. At the scale where most larvae are immigrants, theory predicts spatially homogeneous, temporally stable genetic variation. Empirical studies have suggested that genetic drift interacts with complex dispersal patterns to create chaotic genetic patchiness. Here we use a co-ancestry model and individual-based simulations to test this idea. We found that chaotic genetic patterns (qualified by global FST and spatio-temporal variation in FST's between pairs of samples) arise from the combined effects of (1) genetic drift created by the small local effective population sizes of the sessile phase and variance in contribution among breeding groups and (2) collective dispersal of related individuals in the larval phase. Simulations show that patchiness levels qualitatively comparable to empirical results can be produced by a combination of strong variance in reproductive success and mild collective dispersal. These results call for empirical studies of the effective number of breeders producing larval cohorts, and population genetics at the larval stage. © 2012 The Author(s). Evolution © 2012 The Society for the Study of Evolution.

Biodiversity comparison among phylogenetic diversity metrics and between three North American prairies1

PubMed Central

Kellar, P. Roxanne (Steele); Ahrendsen, Dakota L.; Aust, Shelly K.; Jones, Amanda R.; Pires, J. Chris

2015-01-01

Protection of Earth’s ecosystems requires identification of geographical areas of greatest biodiversity. Assessment of biodiversity begins with knowledge of the evolutionary histories of species in a geographic area. Multiple phylogenetic diversity (PD) metrics have been developed to describe biodiversity beyond species counts, but sufficient empirical studies, particularly at fine phylogenetic scales, have not been conducted to provide conservation planners with evidence for incorporating PD metrics into selection of priority regions. We review notable studies that are contributing to a growing database of empirical results, we report on the effect of using high-throughput sequencing to estimate the phylogenies used to calculate PD metrics, and we discuss difficulties in selecting appropriate diversity indices. We focused on two of the most speciose angiosperm families in prairies—Asteraceae and Fabaceae—and compared 12 PD metrics and four traditional measures of biodiversity between three North American prairie sites. The varying results from the literature and from the current data reveal the wide range of applications of PD metrics and the necessity for many more empirical studies. The accumulation of results from further investigations will eventually lead to a scientific understanding upon which conservation planners can make informed decisions about where to apply limited preservation funds. PMID:26191461

Equilibrium charge state distributions of Ni, Co, and Cu beams in molybdenum foil at 2 MeV/u

NASA Astrophysics Data System (ADS)

Gastis, Panagiotis; Perdikakis, George; Robertson, Daniel; Bauder, Will; Skulski, Michael; Collon, Phillipe; Anderson, Tyler; Ostdiek, Karen; Aprahamian, Ani; Lu, Wenting; Almus, Robert

2015-10-01

The charge states of heavy-ions are important for the study of nuclear reactions in inverse kinematics when electromagnetic recoil mass spectrometers are used. The passage of recoil products through a material, like the windows of gas cells or charge state boosters, results a charge state distribution (CSD) in the exit. This distribution must be known for the extraction of any cross section since only few charge-state can be transmitted through a magnetic separator separator for a given setting. The calculation of CSDs for heavy ions is challenging. Currently we rely on semi-empirical models with unknown accuracy for ion/target combinations in the Z > 20 region. In the present study were measured the CSDs of the stable 60Ni, 59Co, and 63Cu beams while passing through a 1 μm molybdenum foil. The beam energies were 1.84 MeV/u, 2.09 MeV/u, and 2.11 MeV/u for the 60Ni, 59Co, and 63Cu respectively. The results of this study mainly check the accuracy of the semi-empirical models used by the program LISE++, on calculating CSDs for ion/target combinations of Z > 20. In addition, other empirical models on calculating mean charge states were compared and checked.

Review of Eastern coral snake (Micrurus fulvius fulvius) exposures managed by the Florida Poison Information Center Network: 1998-2010.

PubMed

Wood, A; Schauben, J; Thundiyil, J; Kunisaki, T; Sollee, D; Lewis-Younger, C; Bernstein, J; Weisman, R

2013-01-01

Envenomation by the Eastern coral snake is rare but may be associated with significant morbidity. While effective, acquisition of North American Coral Snake Antivenin (NACSAV) is difficult because production was discontinued for many years. The purpose of this study is to characterize coral snake exposures in Florida and determine the effects of varying treatment paradigms on patient outcomes. This study is an observational case series of cases received at Florida poison centers. Included cases were Eastern coral snake exposures occurring between January 1, 1998 and October 31, 2010. Excluded cases included those found to be unrelated or those not followed for at least 24 h post envenomation. Case comments were reviewed to obtain data. Comparisons were made between asymptomatic patients receiving empiric antivenom therapy (empiric group) and those asymptomatic patients who received antivenom upon developing signs of systemic envenomation (withhold group). Of the 553 cases identified, 387 were included in the final analysis. According to case comments, 56.3% of patients had no reported systemic symptoms. Most commonly, patients were reported to have pain (40.6%), paresthesias (28.4%), nausea (12.7%), and emesis (11.4%). NACSAV was administered to 252 patients (65%). Of those patients receiving NACSAV, 18.25% were reported to have had an adverse reaction. Patients in the withhold group (n = 106) had significantly fewer minor, moderate, and major outcomes than patients in the empiric group (n = 134, p < 0.01). While patients in the withhold group had favorable outcomes compared with those in the empiric group, this strategy cannot be applied to all patients presenting asymptomatic to healthcare facilities due to study limitations. Further studies are needed to determine what treatment strategy is most appropriate for asymptomatic patients presenting to healthcare facilities.

A single-station empirical model for TEC over the Antarctic Peninsula using GPS-TEC data

NASA Astrophysics Data System (ADS)

Feng, Jiandi; Wang, Zhengtao; Jiang, Weiping; Zhao, Zhenzhen; Zhang, Bingbing

2017-02-01

Compared with regional or global total electron content (TEC) empirical models, single-station TEC empirical models may exhibit higher accuracy in describing TEC spatial and temporal variations for a single station. In this paper, a new single-station empirical total electron content (TEC) model, called SSM-month, for the O'Higgins Station in the Antarctic Peninsula is proposed by using Global Positioning System (GPS)-TEC data from 01 January 2004 to 30 June 2015. The diurnal variation of TEC in the O'Higgins Station may have changing features in different months, sometimes even in opposite forms, because of ionospheric phenomena, such as the Mid-latitude Summer Nighttime Anomaly (MSNA). To avoid the influence of different diurnal variations, the concept of monthly modeling is proposed in this study. The SSM-month model, which is established by month (including 12 submodels that correspond to the 12 months), can effectively describe the diurnal variation of TEC in different months. Each submodel of the SSM-month model exhibits good agreement with GPS-TEC input data. Overall, the SSM-month model fits the input data with a bias of 0.03 TECU (total electron content unit, 1 TECU = 1016 el m-2) and a standard deviation of 2.78 TECU. This model, which benefits from the modeling method, can effectively describe the MSNA phenomenon without implementing any modeling correction. TEC data derived from Center for Orbit Determination in Europe global ionosphere maps (CODE GIMs), International Reference Ionosphere 2012 (IRI2012), and NeQuick are compared with the SSM-month model in the years of 2001 and 2015-2016. Result shows that the SSM-month model exhibits good consistency with CODE GIMs, which is better than that of IRI2012 and NeQuick, in the O'Higgins Station on the test days.

Evaluation of backscatter dose from internal lead shielding in clinical electron beams using EGSnrc Monte Carlo simulations.

PubMed

De Vries, Rowen J; Marsh, Steven

2015-11-08

Internal lead shielding is utilized during superficial electron beam treatments of the head and neck, such as lip carcinoma. Methods for predicting backscattered dose include the use of empirical equations or performing physical measurements. The accuracy of these empirical equations required verification for the local electron beams. In this study, a Monte Carlo model of a Siemens Artiste linac was developed for 6, 9, 12, and 15 MeV electron beams using the EGSnrc MC package. The model was verified against physical measurements to an accuracy of better than 2% and 2mm. Multiple MC simulations of lead interfaces at different depths, corresponding to mean electron energies in the range of 0.2-14 MeV at the interfaces, were performed to calculate electron backscatter values. The simulated electron backscatter was compared with current empirical equations to ascertain their accuracy. The major finding was that the current set of backscatter equations does not accurately predict electron backscatter, particularly in the lower energies region. A new equation was derived which enables estimation of electron backscatter factor at any depth upstream from the interface for the local treatment machines. The derived equation agreed to within 1.5% of the MC simulated electron backscatter at the lead interface and upstream positions. Verification of the equation was performed by comparing to measurements of the electron backscatter factor using Gafchromic EBT2 film. These results show a mean value of 0.997 ± 0.022 to 1σ of the predicted values of electron backscatter. The new empirical equation presented can accurately estimate electron backscatter factor from lead shielding in the range of 0.2 to 14 MeV for the local linacs.

Major Challenges in Clinical Management of TB/HIV Coinfected Patients in Eastern Europe Compared with Western Europe and Latin America.

PubMed

Efsen, Anne Marie W; Schultze, Anna; Post, Frank A; Panteleev, Alexander; Furrer, Hansjakob; Miller, Robert F; Losso, Marcelo H; Toibaro, Javier; Skrahin, Aliaksandr; Miro, Jose M; Caylà, Joan A; Girardi, Enrico; Bruyand, Mathias; Obel, Niels; Podlekareva, Daria N; Lundgren, Jens D; Mocroft, Amanda; Kirk, Ole

2015-01-01

Rates of TB/HIV coinfection and multi-drug resistant (MDR)-TB are increasing in Eastern Europe (EE). We aimed to study clinical characteristics, factors associated with MDR-TB and predicted activity of empiric anti-TB treatment at time of TB diagnosis among TB/HIV coinfected patients in EE, Western Europe (WE) and Latin America (LA). Between January 1, 2011, and December 31, 2013, 1413 TB/HIV patients (62 clinics in 19 countries in EE, WE, Southern Europe (SE), and LA) were enrolled. Significant differences were observed between EE (N = 844), WE (N = 152), SE (N = 164), and LA (N = 253) in the proportion of patients with a definite TB diagnosis (47%, 71%, 72% and 40%, p<0.0001), MDR-TB (40%, 5%, 3% and 15%, p<0.0001), and use of combination antiretroviral therapy (cART) (17%, 40%, 44% and 35%, p<0.0001). Injecting drug use (adjusted OR (aOR) = 2.03 (95% CI 1.00-4.09), prior anti-TB treatment (3.42 (1.88-6.22)), and living in EE (7.19 (3.28-15.78)) were associated with MDR-TB. Among 585 patients with drug susceptibility test (DST) results, the empiric (i.e. without knowledge of the DST results) anti-TB treatment included ≥3 active drugs in 66% of participants in EE compared with 90-96% in other regions (p<0.0001). In EE, TB/HIV patients were less likely to receive a definite TB diagnosis, more likely to house MDR-TB and commonly received empiric anti-TB treatment with reduced activity. Improved management of TB/HIV patients in EE requires better access to TB diagnostics including DSTs, empiric anti-TB therapy directed at both susceptible and MDR-TB, and more widespread use of cART.

Empirical models for the prediction of ground motion duration for intraplate earthquakes

NASA Astrophysics Data System (ADS)

Anbazhagan, P.; Neaz Sheikh, M.; Bajaj, Ketan; Mariya Dayana, P. J.; Madhura, H.; Reddy, G. R.

2017-07-01

Many empirical relationships for the earthquake ground motion duration were developed for interplate region, whereas only a very limited number of empirical relationships exist for intraplate region. Also, the existing relationships were developed based mostly on the scaled recorded interplate earthquakes to represent intraplate earthquakes. To the author's knowledge, none of the existing relationships for the intraplate regions were developed using only the data from intraplate regions. Therefore, an attempt is made in this study to develop empirical predictive relationships of earthquake ground motion duration (i.e., significant and bracketed) with earthquake magnitude, hypocentral distance, and site conditions (i.e., rock and soil sites) using the data compiled from intraplate regions of Canada, Australia, Peninsular India, and the central and southern parts of the USA. The compiled earthquake ground motion data consists of 600 records with moment magnitudes ranging from 3.0 to 6.5 and hypocentral distances ranging from 4 to 1000 km. The non-linear mixed-effect (NLMEs) and logistic regression techniques (to account for zero duration) were used to fit predictive models to the duration data. The bracketed duration was found to be decreased with an increase in the hypocentral distance and increased with an increase in the magnitude of the earthquake. The significant duration was found to be increased with the increase in the magnitude and hypocentral distance of the earthquake. Both significant and bracketed durations were predicted higher in rock sites than in soil sites. The predictive relationships developed herein are compared with the existing relationships for interplate and intraplate regions. The developed relationship for bracketed duration predicts lower durations for rock and soil sites. However, the developed relationship for a significant duration predicts lower durations up to a certain distance and thereafter predicts higher durations compared to the existing relationships.

Evaluation of backscatter dose from internal lead shielding in clinical electron beams using EGSnrc Monte Carlo simulations

PubMed Central

Marsh, Steven

2015-01-01

Internal lead shielding is utilized during superficial electron beam treatments of the head and neck, such as lip carcinoma. Methods for predicting backscattered dose include the use of empirical equations or performing physical measurements. The accuracy of these empirical equations required verification for the local electron beams. In this study, a Monte Carlo model of a Siemens Artiste linac was developed for 6, 9, 12, and 15 MeV electron beams using the EGSnrc MC package. The model was verified against physical measurements to an accuracy of better than 2% and 2 mm. Multiple MC simulations of lead interfaces at different depths, corresponding to mean electron energies in the range of 0.2–14 MeV at the interfaces, were performed to calculate electron backscatter values. The simulated electron backscatter was compared with current empirical equations to ascertain their accuracy. The major finding was that the current set of backscatter equations does not accurately predict electron backscatter, particularly in the lower energies region. A new equation was derived which enables estimation of electron backscatter factor at any depth upstream from the interface for the local treatment machines. The derived equation agreed to within 1.5% of the MC simulated electron backscatter at the lead interface and upstream positions. Verification of the equation was performed by comparing to measurements of the electron backscatter factor using Gafchromic EBT2 film. These results show a mean value of 0.997±0.022 to 1σ of the predicted values of electron backscatter. The new empirical equation presented can accurately estimate electron backscatter factor from lead shielding in the range of 0.2 to 14 MeV for the local linacs. PACS numbers: 87.53.Bn, 87.55.K‐, 87.56.bd PMID:26699566

Empirical evaluation of H.265/HEVC-based dynamic adaptive video streaming over HTTP (HEVC-DASH)

NASA Astrophysics Data System (ADS)

Irondi, Iheanyi; Wang, Qi; Grecos, Christos

2014-05-01

Real-time HTTP streaming has gained global popularity for delivering video content over Internet. In particular, the recent MPEG-DASH (Dynamic Adaptive Streaming over HTTP) standard enables on-demand, live, and adaptive Internet streaming in response to network bandwidth fluctuations. Meanwhile, emerging is the new-generation video coding standard, H.265/HEVC (High Efficiency Video Coding) promises to reduce the bandwidth requirement by 50% at the same video quality when compared with the current H.264/AVC standard. However, little existing work has addressed the integration of the DASH and HEVC standards, let alone empirical performance evaluation of such systems. This paper presents an experimental HEVC-DASH system, which is a pull-based adaptive streaming solution that delivers HEVC-coded video content through conventional HTTP servers where the client switches to its desired quality, resolution or bitrate based on the available network bandwidth. Previous studies in DASH have focused on H.264/AVC, whereas we present an empirical evaluation of the HEVC-DASH system by implementing a real-world test bed, which consists of an Apache HTTP Server with GPAC, an MP4Client (GPAC) with open HEVC-based DASH client and a NETEM box in the middle emulating different network conditions. We investigate and analyze the performance of HEVC-DASH by exploring the impact of various network conditions such as packet loss, bandwidth and delay on video quality. Furthermore, we compare the Intra and Random Access profiles of HEVC coding with the Intra profile of H.264/AVC when the correspondingly encoded video is streamed with DASH. Finally, we explore the correlation among the quality metrics and network conditions, and empirically establish under which conditions the different codecs can provide satisfactory performance.

Empire: An Analytical Category for Educational Research

ERIC Educational Resources Information Center

Coloma, Roland Sintos

2013-01-01

In this article Roland Sintos Coloma argues for the relevance of empire as an analytical category in educational research. He points out the silence in mainstream studies of education on the subject of empire, the various interpretive approaches to deploying empire as an analytic, and the importance of indigeneity in research on empire and…

Empirical likelihood inference in randomized clinical trials.

PubMed

Zhang, Biao

2017-01-01

In individually randomized controlled trials, in addition to the primary outcome, information is often available on a number of covariates prior to randomization. This information is frequently utilized to undertake adjustment for baseline characteristics in order to increase precision of the estimation of average treatment effects; such adjustment is usually performed via covariate adjustment in outcome regression models. Although the use of covariate adjustment is widely seen as desirable for making treatment effect estimates more precise and the corresponding hypothesis tests more powerful, there are considerable concerns that objective inference in randomized clinical trials can potentially be compromised. In this paper, we study an empirical likelihood approach to covariate adjustment and propose two unbiased estimating functions that automatically decouple evaluation of average treatment effects from regression modeling of covariate-outcome relationships. The resulting empirical likelihood estimator of the average treatment effect is as efficient as the existing efficient adjusted estimators 1 when separate treatment-specific working regression models are correctly specified, yet are at least as efficient as the existing efficient adjusted estimators 1 for any given treatment-specific working regression models whether or not they coincide with the true treatment-specific covariate-outcome relationships. We present a simulation study to compare the finite sample performance of various methods along with some results on analysis of a data set from an HIV clinical trial. The simulation results indicate that the proposed empirical likelihood approach is more efficient and powerful than its competitors when the working covariate-outcome relationships by treatment status are misspecified.

An empirical investigation of spatial differentiation and price floor regulations in retail markets for gasoline

NASA Astrophysics Data System (ADS)

Houde, Jean-Francois

In the first essay of this dissertation, I study an empirical model of spatial competition. The main feature of my approach is to formally specify commuting paths as the "locations" of consumers in a Hotelling-type model of spatial competition. The main consequence of this location assumption is that the substitution patterns between stations depend in an intuitive way on the structure of the road network and the direction of traffic flows. The demand-side of the model is estimated by combining a model of traffic allocation with econometric techniques used to estimate models of demand for differentiated products (Berry, Levinsohn and Pakes (1995)). The estimated parameters are then used to evaluate the importance of commuting patterns in explaining the distribution of gasoline sales, and compare the economic predictions of the model with the standard home-location model. In the second and third essays, I examine empirically the effect of a price floor regulation on the dynamic and static equilibrium outcomes of the gasoline retail industry. In particular, in the second essay I study empirically the dynamic entry and exit decisions of gasoline stations, and measure the impact of a price floor on the continuation values of staying in the industry. In the third essay, I develop and estimate a static model of quantity competition subject to a price floor regulation. Both models are estimated using a rich panel dataset on the Quebec gasoline retail market before and after the implementation of a price floor regulation.

Relative Values: Perspectives on a Neuroimaging Technology From Above and Within the Ethical Landscape.

PubMed

Samuel, Gabrielle; Cribb, Alan; Owens, John; Williams, Clare

2016-09-01

In this paper we contribute to "sociology in bioethics" and help clarify the range of ways sociological work can contribute to ethics scholarship. We do this using a case study of an innovative neurotechnology, functional magnetic resonance imaging, and its use to attempt to diagnose and communicate with severely brain-injured patients. We compare empirical data from interviews with relatives of patients who have a severe brain injury with perspectives from mainstream bioethics scholars. We use the notion of an "ethical landscape" as an analogy for the different ethical positions subjects can take-whereby a person's position relative to the landscape makes a difference to the way they experience and interact with it. We show that, in comparison to studying abstract ethics "from above" the ethical landscape, which involves universal generalizations and global judgements, studying ethics empirically "from the ground," within the ethical landscape foregrounds a more plural and differentiated picture. We argue it is important not to treat empirical ethics as secondary to abstract ethics, to treat on-the-ground perspectives as useful only insofar as they can inform ethics from above. Rather, empirical perspectives can illuminate the plural vantage points in ethical judgments, highlight the "lived" nature of ethical reasoning, and point to all ethical vantage points as being significant. This is of epistemic importance to normative ethics, since researchers who pay attention to the various positions in and trajectories through the ethical landscape are unlikely to think about ethics in terms of abstract agency-as can happen with top-down ethics-or to elide agency with the agency of policymakers. Moreover, empirical perspectives may have transformative implications for people on the ground, especially where focus on the potential harms and benefits they face brings their experiences and interests to the forefront of ethical and policy discussion.

Evaluation of Regression Models of Balance Calibration Data Using an Empirical Criterion

NASA Technical Reports Server (NTRS)

Ulbrich, Norbert; Volden, Thomas R.

2012-01-01

An empirical criterion for assessing the significance of individual terms of regression models of wind tunnel strain gage balance outputs is evaluated. The criterion is based on the percent contribution of a regression model term. It considers a term to be significant if its percent contribution exceeds the empirical threshold of 0.05%. The criterion has the advantage that it can easily be computed using the regression coefficients of the gage outputs and the load capacities of the balance. First, a definition of the empirical criterion is provided. Then, it is compared with an alternate statistical criterion that is widely used in regression analysis. Finally, calibration data sets from a variety of balances are used to illustrate the connection between the empirical and the statistical criterion. A review of these results indicated that the empirical criterion seems to be suitable for a crude assessment of the significance of a regression model term as the boundary between a significant and an insignificant term cannot be defined very well. Therefore, regression model term reduction should only be performed by using the more universally applicable statistical criterion.

Empiric transcatheter arterial embolization for massive bleeding from duodenal ulcers: efficacy and complications.

PubMed

Ichiro, Ikushima; Shushi, Higashi; Akihiko, Ishii; Yasuhiko, Iryo; Yasuyuki, Yamashita

2011-07-01

To evaluate the efficacy and safety of empiric transcatheter arterial embolization (TAE) for patients with massive bleeding from duodenal ulcers. During January 2000 and December 2009, 59 patients with duodenal ulcer bleeding in whom TAE was attempted after endoscopic therapy failed were retrospectively analyzed. The patients were divided into empiric TAE (n = 36) and identifiable TAE (n = 23) groups according to angiographic findings with or without identification of the bleeding sites. The technical and clinical success rate, recurrent bleeding rate, procedure-related complications, and clinical outcomes were evaluated. The technical and clinical success rates of TAE were 100% and 83%. The recurrent bleeding rate, clinical success, duodenal stenosis, and 30-day mortality after TAE were not significantly different between the empiric and identifiable TAE groups. A high rate of technical and clinical success was obtained with empiric TAE comparable to identifiable TAE in patients with massive bleeding from duodenal ulcers. There were no severe complications. Empiric TAE is an effective and safe method when a bleeding site cannot determined by angiography. Copyright © 2011 SIR. Published by Elsevier Inc. All rights reserved.

Large-scale compensation of errors in pairwise-additive empirical force fields: comparison of AMBER intermolecular terms with rigorous DFT-SAPT calculations.

PubMed

Zgarbová, Marie; Otyepka, Michal; Sponer, Jirí; Hobza, Pavel; Jurecka, Petr

2010-09-21

The intermolecular interaction energy components for several molecular complexes were calculated using force fields available in the AMBER suite of programs and compared with Density Functional Theory-Symmetry Adapted Perturbation Theory (DFT-SAPT) values. The extent to which such comparison is meaningful is discussed. The comparability is shown to depend strongly on the intermolecular distance, which means that comparisons made at one distance only are of limited value. At large distances the coulombic and van der Waals 1/r(6) empirical terms correspond fairly well with the DFT-SAPT electrostatics and dispersion terms, respectively. At the onset of electronic overlap the empirical values deviate from the reference values considerably. However, the errors in the force fields tend to cancel out in a systematic manner at equilibrium distances. Thus, the overall performance of the force fields displays errors an order of magnitude smaller than those of the individual interaction energy components. The repulsive 1/r(12) component of the van der Waals expression seems to be responsible for a significant part of the deviation of the force field results from the reference values. We suggest that further improvement of the force fields for intermolecular interactions would require replacement of the nonphysical 1/r(12) term by an exponential function. Dispersion anisotropy and its effects are discussed. Our analysis is intended to show that although comparing the empirical and non-empirical interaction energy components is in general problematic, it might bring insights useful for the construction of new force fields. Our results are relevant to often performed force-field-based interaction energy decompositions.

Bacterial Etiology and Antibiotic Resistance Profile of Community-Acquired Urinary Tract Infections in a Cameroonian City.

PubMed

Nzalie, Rolf Nyah-Tuku; Gonsu, Hortense Kamga; Koulla-Shiro, Sinata

2016-01-01

Introduction. Community-acquired urinary tract infections (CAUTIs) are usually treated empirically. Geographical variations in etiologic agents and their antibiotic sensitivity patterns are common. Knowledge of antibiotic resistance trends is important for improving evidence-based recommendations for empirical treatment of UTIs. Our aim was to determine the major bacterial etiologies of CAUTIs and their antibiotic resistance patterns in a cosmopolitan area of Cameroon for comparison with prescription practices of local physicians. Methods. We performed a cross-sectional descriptive study at two main hospitals in Yaoundé, collecting a clean-catch mid-stream urine sample from 92 patients having a clinical diagnosis of UTI. The empirical antibiotherapy was noted, and identification of bacterial species was done on CLED agar; antibiotic susceptibility testing was performed using the Kirby-Bauer disc diffusion method. Results. A total of 55 patients had samples positive for a UTI. Ciprofloxacin and amoxicillin/clavulanic acid were the most empirically prescribed antibiotics (30.9% and 23.6%, resp.); bacterial isolates showed high prevalence of resistance to both compounds. Escherichia coli (50.9%) was the most common pathogen, followed by Klebsiella pneumoniae (16.4%). Prevalence of resistance for ciprofloxacin was higher compared to newer quinolones. Conclusions. E. coli and K. pneumoniae were the predominant bacterial etiologies; the prevalence of resistance to commonly prescribed antibiotics was high.

Influence of impact conditions on plasma generation during hypervelocity impact by aluminum projectile

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

Song, Weidong, E-mail: swdgh@bit.edu.cn; Lv, Yangtao; Li, Jianqiao

2016-07-15

For describing hypervelocity impact (relative low-speed as related to space debris and much lower than travelling speed of meteoroids) phenomenon associated with plasma generation, a self-developed 3D code was advanced to numerically simulate projectiles impacting on a rigid wall. The numerical results were combined with a new ionization model which was developed in an early study to calculate the ionized materials during the impact. The calculated results of ionization were compared with the empirical formulas concluded by experiments in references and a good agreement was obtained. Then based on the reliable 3D numerical code, a series of impacts with differentmore » projectile configurations were simulated to investigate the influence of impact conditions on hypervelocity impact generated plasma. It was found that the form of empirical formula needed to be modified. A new empirical formula with a critical impact velocity was advanced to describe the velocity dependence of plasma generation and the parameters of the modified formula were ensured by the comparison between the numerical predictions and the empirical formulas. For different projectile configurations, the changes of plasma charges with time are different but the integrals of charges on time almost stayed in the same level.« less

Empirical Corrections to Nutation Amplitudes and Precession Computed from a Global VLBI Solution

NASA Astrophysics Data System (ADS)

Schuh, H.; Ferrandiz, J. M.; Belda-Palazón, S.; Heinkelmann, R.; Karbon, M.; Nilsson, T.

2017-12-01

The IAU2000A nutation and IAU2006 precession models were adopted to provide accurate estimations and predictions of the Celestial Intermediate Pole (CIP). However, they are not fully accurate and VLBI (Very Long Baseline Interferometry) observations show that the CIP deviates from the position resulting from the application of the IAU2006/2000A model. Currently, those deviations or offsets of the CIP (Celestial Pole Offsets - CPO), can only be obtained by the VLBI technique. The accuracy of the order of 0.1 milliseconds of arc (mas) allows to compare the observed nutation with theoretical prediction model for a rigid Earth and constrain geophysical parameters describing the Earth's interior. In this study, we empirically evaluate the consistency, systematics and deviations of the IAU 2006/2000A precession-nutation model using several CPO time series derived from the global analysis of VLBI sessions. The final objective is the reassessment of the precession offset and rate, and the amplitudes of the principal terms of nutation, trying to empirically improve the conventional values derived from the precession/nutation theories. The statistical analysis of the residuals after re-fitting the main nutation terms demonstrates that our empirical corrections attain an error reduction by almost 15 micro arc seconds.

The Role of Learning and Career Guidance for Managing Mid-Career Transitions--Comparing Germany and Denmark

ERIC Educational Resources Information Center

Haasler, Simone R.; Barabasch, Antje

2015-01-01

In Germany and Denmark, the systems of further education and career guidance are well developed, offering a wide range of services and learning opportunities for targeted, specific and also general skills development. Based on an empirical study with mid-career individuals in both countries, the article investigates how the different systems…

Three Scales to Measure Burnout of Primary School Teachers: Empirical Evidence on Their Adequacy

ERIC Educational Resources Information Center

Platsidou, Maria; Daniilidou, Athena

2016-01-01

This study aimed at comparing the psychometric properties of three measures of burnout administered in 320 Greek primary school teachers, namely the Maslach Burnout Inventory (Maslach and Jackson 1982), the Burnout Measure (Pines and Aronson 1988) and the Copenhagen Burnout Inventory (Kristensen et al. 2005). Confirmatory factor analysis tested a…

Assessing University Students: Searching for an English Language Exit Test

ERIC Educational Resources Information Center

Qian, David D.

2007-01-01

In order to motivate university students to improve their English proficiency, the Hong Kong government decided to adopt a common exit English language test for all graduating students. In the process of selecting a suitable measure for this purpose, an empirical study with a sample of over 240 students was conducted to compare two English…

Personality Assessment Inventory Profiles of Deployed Combat Troops: An Empirical Investigation of Normative Performance

ERIC Educational Resources Information Center

Morey, Leslie C.; Lowmaster, Sara E.; Coldren, Rodney L.; Kelly, Mark P.; Parish, Robert V.; Russell, Michael L.

2011-01-01

The present study examined the normative scores and psychometric properties of the Personality Assessment Inventory (PAI; Morey, 1991) within a non-treatment-seeking sample of soldiers deployed to combat zones in Iraq, compared with a sample of community adults matched with respect to age and gender. Results indicate the scores and properties of…

Measuring Learning Gain: Comparing Anatomy Drawing Screencasts and Paper-Based Resources

ERIC Educational Resources Information Center

Pickering, James D.

2017-01-01

The use of technology-enhanced learning (TEL) resources is now a common tool across a variety of healthcare programs. Despite this popular approach to curriculum delivery there remains a paucity in empirical evidence that quantifies the change in learning gain. The aim of the study was to measure the changes in learning gain observed with anatomy…

Support Systems for Poor Readers: Empirical Data from Six EU Member States

ERIC Educational Resources Information Center

Ise, Elena; Blomert, Leo; Bertrand, Daisy; Faisca, Luis; Puolakanaho, Anne; Saine, Nina L.; Suranyi, Zsuzsanna; Vaessen, Anniek; Csepe, Valeria; Lyytinen, Heikki; Reis, Alexandra; Ziegler, Johannes C.; Schulte-Korne, Gerd

2011-01-01

This study surveyed and compared support systems for poor readers in six member states of the European Union (EU). The goal was to identify features of effective support systems. A large-scale questionnaire survey was conducted among mainstream teachers (n = 4,210) and remedial teachers (n = 2,395). Results indicate that the six support systems…

From Description to Explanation: An Empirical Exploration of the African-American Pipeline Problem in STEM

ERIC Educational Resources Information Center

Brown, Bryan A.; Henderson, J. Bryan; Gray, Salina; Donovan, Brian; Sullivan, Shayna; Patterson, Alexis; Waggstaff, William

2016-01-01

We conducted a mixed-methods study of matriculation issues for African-Americans in the STEM pipeline. The project compares the experiences of students currently majoring in science (N?=?304) with the experiences of those who have succeeded in earning science degrees (N?=?307). Participants were surveyed about their pipeline experiences based on…

A Critical Analysis of Western Perspectives on Families of Arab Descent

ERIC Educational Resources Information Center

Beitin, Ben K.; Allen, Katherine R.; Bekheet, Maureen

2010-01-01

Western research on families of Arab descent has increased in the current decade, compared to the previous 30 years. In this review of 256 empirical articles, through a critical postcolonial lens, domestic violence and family planning were the two most established areas of study. Generally, samples have come from a small group of countries such as…

Collaborative Learning with Screen-Based Simulation in Health Care Education: An Empirical Study of Collaborative Patterns and Proficiency Development

ERIC Educational Resources Information Center

Hall, L. O.; Soderstrom, T.; Ahlqvist, J.; Nilsson, T.

2011-01-01

This article is about collaborative learning with educational computer-assisted simulation (ECAS) in health care education. Previous research on training with a radiological virtual reality simulator has indicated positive effects on learning when compared to a more conventional alternative. Drawing upon the field of Computer-Supported…

Factor Structure of the Counselor Burnout Inventory in a Sample of Sexual Offender and Sexual Abuse Therapists

ERIC Educational Resources Information Center

Lee, Jayoung; Wallace, Sam; Puig, Ana; Choi, Bo Young; Nam, Suk Kyung; Lee, Sang Min

2010-01-01

This study empirically tested and compared three different models of factor structure with a sample of therapists working with sexual offenders, survivors of sexual abuse, or both. Results indicated that a modified five-factor model was the most appropriate. Practical implications for sexual offender/abuse survivor therapists are discussed.…

A Comparison of Three Strategies for Scale Construction to Predict a Specific Behavioral Outcome

ERIC Educational Resources Information Center

Garb, Howard N.; Wood, James M.; Fiedler, Edna R.

2011-01-01

Using 65 items from a mental health screening questionnaire, the History Opinion Inventory-Revised (HOI-R), the present study compared three strategies of scale construction--(1) internal (based on factor analysis), (2) external (based on empirical performance) and (3) intuitive (based on clinicians' opinion)--to predict whether 203,595 U.S. Air…

The "Promise" of Three Methods of Word Association Analysis to L2 Lexical Research

ERIC Educational Resources Information Center

Zareva, Alla; Wolter, Brent

2012-01-01

The present study is an attempt to empirically test and compare the results of three methods of word association (WA) analysis. Two of the methods--namely, associative commonality and nativelikeness, and lexico-syntactic patterns of associative organization--have been traditionally used in both first language (L1) and second language (L2)…

Poverty Is Not a Human Characteristic: A Retrospective Study of Comprehending and Educating Impoverished Children

ERIC Educational Resources Information Center

Holmlund, Kerstin

2012-01-01

This article describes and compares the differences between a feature-oriented understanding and a relational understanding of a child's behavior and the different ways of educating children which these two empirical and theoretical perspectives offer. The feature-oriented perspective focuses on the nature and character of impoverished children as…

Light Attenuation in a 14-year-old Loblolly Pine Stand as Influenced by Fertilization and Irrigation

Treesearch

D.A. Sampson; H. Lee Allen

1998-01-01

We examined empirical and simulated estimates of canopy light attenuation at SETRES (Southeast Tree Research and Education Site) a 2x2 factorial study of water and nutrients. Fertilized plots had signiticantly lower under-canopy PAR transmittance (Tc) when compared to non-fertilized plots. Light interception efftciency as measured by the...

Divergent Development of Gross Motor Skills in Children Who Are Blind or Sighted

ERIC Educational Resources Information Center

Brambring, Michael

2006-01-01

This empirical study compared the average ages at which four congenitally blind children acquired 29 gross motor skills with age norms for sighted children. The results indicated distinct developmental delays in the acquisition of motor skills and a high degree of variability in developmental delays within and across the six subdomains that were…

Measuring soil moisture with imaging radars

NASA Technical Reports Server (NTRS)

Dubois, Pascale C.; Vanzyl, Jakob; Engman, Ted

1995-01-01

An empirical model was developed to infer soil moisture and surface roughness from radar data. The accuracy of the inversion technique is assessed by comparing soil moisture obtained with the inversion technique to in situ measurements. The effect of vegetation on the inversion is studied and a method to eliminate the areas where vegetation impairs the algorithm is described.

The Feminization of School Hypothesis Called into Question among Junior and High School Students

ERIC Educational Resources Information Center

Verniers, Catherine; Martinot, Delphine; Dompnier, Benoît

2016-01-01

Background: The feminization of school hypothesis suggests that boys underachieve in school compared to girls because school rewards feminine characteristics that are at odds with boys' masculine features. Aims: The feminization of school hypothesis lacks empirical evidence. The aim of this study was to test this hypothesis by examining the extent…

Emotion Perception in Asperger's Syndrome and High-Functioning Autism: The Importance of Diagnostic Criteria and Cue Intensity

ERIC Educational Resources Information Center

Mazefsky, Carla A.; Oswald, Donald P.

2007-01-01

This study compared emotion perception accuracy between children with Asperger's syndrome (AS) and high-functioning autism (HFA). Thirty children were diagnosed with AS or HFA based on empirically supported diagnostic criteria and administered an emotion perception test consisting of facial expressions and tone of voice cues that varied in…

The Impact of IT Capability on Employee Capability, Customer Value, Customer Satisfaction, and Business Performance

ERIC Educational Resources Information Center

Chae, Ho-Chang

2009-01-01

This study empirically examines the impact of IT capability on firms' performance and evaluates whether firms' IT capabilities play a role in improving employee capability, customer value, customer satisfaction, and ultimately business performance. The results were based on comparing the business performance of the IT leader companies with that of…

Teachers' Pedagogical Differences during ESL Block among Bilingual and English-Immersion Kindergarten Classrooms in a Randomized Trial Study

ERIC Educational Resources Information Center

Lara-Alecio, Rafael; Tong, Fuhui; Irby, Beverly J.; Mathes, Patricia

2009-01-01

Using a low-inference observational instrument, the authors empirically described and compared pedagogical behaviors in bilingual and structured English-immersion programs serving Spanish-speaking English language learners in a large urban school district in Southeast Texas. The two programs included both intervention/control of each type during…

Lutheran Adolescent Spiritual Development: The Effect of School Attendance on Spiritual Transformation Inventory Test Scores

ERIC Educational Resources Information Center

Weider, Michael James

2013-01-01

Lutheran schools have been established to nurture and disciple children into the Christian faith. However, empirical evidence is lacking that Lutheran schools are accomplishing this goal. The purpose of this Causal comparative and Correlational study was to determine whether attendance at Lutheran or Public schools made a statistically significant…

Tough or Tender: (Dis)Similarities in White College Students' Perceptions of Black and White Women

ERIC Educational Resources Information Center

Donovan, Roxanne A.

2011-01-01

Although intersectional theory and empirical evidence suggest that race impacts how women are perceived, there is a dearth of research on how the dominant culture stereotypes Black women compared to White women. The current study addresses this gap using an intersectional framework to investigate White college students' stereotypes of Black and…

What Is "Good" Technical Communication? A Comparison of the Standards of Writing and Engineering Instructors.

ERIC Educational Resources Information Center

Smith, Summer

2003-01-01

Presents the results of an empirical study comparing writing and engineering instructors' responses to students' technical writing. Indicates that the gap between engineering and writing teachers' standards for evaluating technical writing is not as wide as is generally assumed. Concludes that the differences that do emerge suggest ways that the…

Nitrous oxide, methane emission, and yield-scaled emission from organically and conventionally managed systems

USDA-ARS?s Scientific Manuscript database

There is a gap in empirical greenhouse gas (GHG) data from many regions of the USA including the northern Corn Belt. This study compared nitrous oxide (N2O) emission in diverse, low-tillage conventionally- and organically-managed systems. Both systems had a four-year rotation, mole-knife, strip till...

Divergent Development of Verbal Skills in Children Who Are Blind or Sighted

ERIC Educational Resources Information Center

Journal of Visual Impairment & Blindness, 2007

2007-01-01

This empirical study compared the average ages at which four children with congenital blindness acquired 29 verbal skills with given age norms for sighted children. The results indicated only small developmental delays in the acquisition of verbal skills in the four children, but a high degree of variability in developmental delays within and…

The Content Validity of Juvenile Psychopathy: An Empirical Examination

ERIC Educational Resources Information Center

Lynam, Donald R.; Derefinko, Karen J.; Caspi, Avshalom; Loeber, Rolf; Stouthamer-Loeber, Magda

2007-01-01

This study examined the content validity of a juvenile psychopathy measure, the Childhood Psychopathy Scale (CPS; D. R. Lynam, 1997), based on a downward translation of an adult instrument, the Hare Psychopathy Checklist-Revised (PCL-R; R. D. Hare, 1991). The CPS was compared with two other indices of juvenile psychopathy: (a) an index derived…

In Support of Coaching Models of Management and Leadership: A Comparative Study of Empirically Derived Managerial Coaching/Facilitating Learning Behaviors

ERIC Educational Resources Information Center

Hamlin, Bob; Ellinger, Andrea D.; Beattie, Rona S.

2004-01-01

The concept of managers assuming developmental roles such as coaches and learning facilitators has gained considerable attention in recent years as organizations seek to leverage learning by creating infrastructures that foster employee learning and development. Despite the increased focus on coaching, the literature base remains atheoretical.…

A Comparative Study of the Variables Used to Measure Syntactic Complexity and Accuracy in Task-Based Research

ERIC Educational Resources Information Center

Inoue, Chihiro

2016-01-01

The constructs of complexity, accuracy and fluency (CAF) have been used extensively to investigate learner performance on second language tasks. However, a serious concern is that the variables used to measure these constructs are sometimes used conventionally without any empirical justification. It is crucial for researchers to understand how…

Correlates of Conduct Problems and Depression Comorbidity in Elementary School Boys and Girls Receiving Special Educational Services

ERIC Educational Resources Information Center

Poirier, Martine; Déry, Michèle; Toupin, Jean; Verlaan, Pierrette; Lemelin, Jean-Pascal; Jagiellowicz, Jadzia

2015-01-01

There is limited empirical research on the correlates of conduct problems (CP) and depression comorbidity during childhood. This study investigated 479 elementary school children (48.2% girls). It compared children with comorbidity to children with CP only, depression only, and control children on individual, academic, social, and family…

Solving Developmental Tasks in Adolescents with a Chronic Physical Illness or Physical/Sensory Disability: A Meta-Analysis

ERIC Educational Resources Information Center

Pinquart, Martin; Pfeiffer, Jens P.

2015-01-01

Chronic illnesses and disabilities may impair the attainment of age-typical developmental tasks, such as forming relationships with peers and gaining autonomy. Based on a systematic search in electronic databases and cross-referencing, 447 quantitative empirical studies were included which compared the attainment of developmental tasks of…

Keeping Students "on Their Toes and on Their Game": Serendipitous Findings in Students' Assessments and Reactions

ERIC Educational Resources Information Center

Pelletier, Kathie L.

2017-01-01

This study extends the empirical findings of the use of continuous, lecture-embedded assessments to increase engagement and enhance learning. Outcome data (exam performance and attendance rates) from college students in three upper-division business course sections who took quizzes and wrote two-minute papers (test group) were compared to outcome…

Divergent Development of Manual Skills in Children Who Are Blind or Sighted

ERIC Educational Resources Information Center

Brambring, Michael

2007-01-01

This empirical study compared the average ages at which four children with congenital blindness acquired 32 fine motor skills with age norms for sighted children. The results indicated that the children experienced extreme developmental delays in the acquisition of manual skills and a high degree of variability in developmental delays within and…

The Impact of School Design on Academic Achievement in the Palestinian Territories: An Empirical Study

ERIC Educational Resources Information Center

Matar, Mohammed; Brighith, Imad

2010-01-01

This article outlines a research project that aimed to gather first-hand data from school users (pupils, teachers, school principals), as well as academic performance data from pupils. The project compared data obtained from users of "new and site-specific" and "standard" schools in order to show whether more attractive and…

Student Plagiarism in Higher Education in Vietnam: An Empirical Study

ERIC Educational Resources Information Center

Do Ba, Khang; Do Ba, Khai; Lam, Quoc Dung; Le, Dao Thanh Binh An; Nguyen, Phuong Lien; Nguyen, Phuong Quynh; Pham, Quoc Loc

2017-01-01

This paper assesses and compares the prevalence of plagiarism across different student and assignment characteristics at a university in Vietnam, using the similarity index reported by the text-matching software Turnitin as a proxy measure of plagiarism on a sample of 681 student papers. The findings present a level of match higher than reported…

Constant and Progressive Time Delay Procedures for Teaching Children with Autism: A Literature Review

ERIC Educational Resources Information Center

Walker, Gabriela

2008-01-01

A review of 22 empirical studies examining the use of constant (CTD) and progressive (PTD) time delay procedures employed with children with autism frames an indirect analysis of the demographic, procedural, methodological, and outcome parameters of existing research. None of the previous manuscripts compared the two response prompting procedures.…

Evaluations of alternative methods for monitoring and estimating responses of salmon productivity in the North Pacific to future climatic change and other processes: A simulation study

EPA Science Inventory

Estimation of the relative influence of climate change, compared to other human activities, on dynamics of Pacific salmon (Oncorhynchus spp.) populations can help management agencies take appropriate management actions. We used empirically based simulation modelling of 48 sockeye...

Empirical Approaches to Measuring the Intelligibility of Different Varieties of English in Predicting Listener Comprehension

ERIC Educational Resources Information Center

Kang, Okim; Thomson, Ron I.; Moran, Meghan

2018-01-01

This study compared five research-based intelligibility measures as they were applied to six varieties of English. The objective was to determine which approach to measuring intelligibility would be most reliable for predicting listener comprehension, as measured through a listening comprehension test similar to the Test of English as a Foreign…

Combining Excellence and Ethics: Implications for Moral Education for the Gifted

ERIC Educational Resources Information Center

Tirri, Kirsi

2011-01-01

In this article the current empirical research on morality and giftedness is reviewed with an emphasis on moral sensitivity. The component of moral judgment has been the most studied aspect in morality. Although high-ability students have been shown to be superior in moral judgment when compared to average-ability students, morality includes other…

Not Alone: Tracing the Origins of Very-Low-Mass Stars and Brown Dwarfs Through Multiplicity Studies

NASA Astrophysics Data System (ADS)

Burgasser, A. J.; Reid, I. N.; Siegler, N.; Close, L.; Allen, P.; Lowrance, P.; Gizis, J.

The properties of multiple stellar systems have long provided important empirical constraints for star-formation theories, enabling (along with several other lines of evidence) a concrete, qualitative picture of the birth and early evolution of normal stars. At very low masses (VLM; M ? 0.1 solar mass), down to and below the hydrogen-burning minimum mass, our understanding of formation processes is not as clear, with several competing theories now under consideration. One means of testing these theories is through the empirical characterization of VLM multiple systems. Here, we review the results of various VLM multiplicity studies to date. These systems can be generally characterized as closely separated (93% have projected separations ? < 20 AU), near equal-mass (77% have M2/M1 ? 0.8) and occurring infrequently (perhaps 10-30% of systems are binary). Both the frequency and maximum separation of stellar and brown dwarf binaries steadily decrease for lower system masses, suggesting that VLM binary formation and/or evolution may be a mass-dependent process. There is evidence for a fairly rapid decline in the number of loosely bound systems below ~0.3 solar mass, corresponding to a factor of 10-20 increase in the minimum binding energy of VLM binaries as compared to more massive stellar binaries. This wide-separation "desert" is present among both field (~1-5 G.y.) and older (>100 m.y.) cluster systems, while the youngest (<10 m.y.) VLM binaries, particularly those in nearby, low-density star-forming regions, appear to have somewhat different systemic properties. We compare these empirical trends to predictions laid out by current formation theories, and outline future observational studies needed to probe the full parameter space of the lowest-mass multiple systems.

The AFDD International Dynamic Stall Workshop on Correlation of Dynamic Stall Models with 3-D Dynamic Stall Data

NASA Technical Reports Server (NTRS)

Tan, C. M.; Carr, L. W.

1996-01-01

A variety of empirical and computational fluid dynamics two-dimensional (2-D) dynamic stall models were compared to recently obtained three-dimensional (3-D) dynamic stall data in a workshop on modeling of 3-D dynamic stall of an unswept, rectangular wing, of aspect ratio 10. Dynamic stall test data both below and above the static stall angle-of-attack were supplied to the participants, along with a 'blind' case where only the test conditions were supplied in advance, with results being compared to experimental data at the workshop itself. Detailed graphical comparisons are presented in the report, which also includes discussion of the methods and the results. The primary conclusion of the workshop was that the 3-D effects of dynamic stall on the oscillating wing studied in the workshop can be reasonably reproduced by existing semi-empirical models once 2-D dynamic stall data have been obtained. The participants also emphasized the need for improved quantification of 2-D dynamic stall.

Diagnostic classification of eating disorders in children and adolescents: How does DSM-IV-TR compare to empirically-derived categories?

PubMed Central

Eddy, Kamryn T.; le Grange, Daniel; Crosby, Ross D.; Hoste, Renee Rienecke; Doyle, Angela Celio; Smyth, Angela; Herzog, David B.

2009-01-01

Objective The purpose of this study was to empirically derive eating disorder phenotypes in a clinical sample of children and adolescents using latent profile analysis (LPA) and compare these latent profile (LP) groups to the DSM-IV-TR eating disorder categories. Method Eating disorder symptom data collected from 401 youth (ages 7–19; mean 15.14 ± 2.35y) seeking eating disorder treatment were included in LPA; general linear models were used to compare LP groups to DSM-IV-TR eating disorder categories on pre-treatment and outcome indices. Results Three LP groups were identified: LP1 (n=144), characterized binge eating and purging (“Binge/purge”); LP2 (n=126), characterized by excessive exercise and extreme eating disorder cognitions (“Exercise-extreme cognitions”); and LP3 (n=131), characterized by minimal eating disorder behaviors and cognitions (“Minimal behaviors/cognitions”). Identified LPs imperfectly resembled DSM-IV-TR eating disorders. LP1 resembled bulimia nervosa; LP2 and LP3 broadly resembled anorexia nervosa with a relaxed weight criterion, differentiated by excessive exercise and severity of eating disorder cognitions. LP groups were more differentiated than the DSM-IV-TR categories across pre-treatment eating disorder and general psychopathology indices, as well as weight change at follow-up. Neither LP nor DSM-IV-TR categories predicted change in binge/purge behaviors. Validation analyses suggest these empirically-derived groups improve upon the current DSM-IV-TR categories. Conclusions In children and adolescents, revisions for DSM-V should consider recognition of patients with minimal cognitive eating disorder symptoms. PMID:20410717

Drought impacts on phloem transport

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

Sevanto, Sanna Annika

We report drought impacts on phloem transport have attracted attention only recently, despite the well-established, and empirically verified theories on drought impacts on water transport in plants in general. This is because studying phloem transport is challenging. Phloem tissue is relatively small and delicate, and it has often been assumed not to be impacted by drought, or having insignificant impact on plant function or survival compared to the xylem. New evidence, however, suggests that drought responses of the phloem might hold the key for predicting plant survival time during drought or revival capacity after drought. Lastly, this review summarizes currentmore » theories and empirical evidence on how drought might impact phloem transport, and evaluates these findings in relation to plant survival during drought.« less

Drought impacts on phloem transport

DOE PAGES

Sevanto, Sanna Annika

2018-02-12

We report drought impacts on phloem transport have attracted attention only recently, despite the well-established, and empirically verified theories on drought impacts on water transport in plants in general. This is because studying phloem transport is challenging. Phloem tissue is relatively small and delicate, and it has often been assumed not to be impacted by drought, or having insignificant impact on plant function or survival compared to the xylem. New evidence, however, suggests that drought responses of the phloem might hold the key for predicting plant survival time during drought or revival capacity after drought. Lastly, this review summarizes currentmore » theories and empirical evidence on how drought might impact phloem transport, and evaluates these findings in relation to plant survival during drought.« less

A process for developing and revising a learning progression on sea level rise using learners' explanations

NASA Astrophysics Data System (ADS)

McDonald, Robert Christopher

The purpose of this study was to explore the process of developing a learning progression (LP) on constructing explanations about sea level rise. I used a learning progressions theoretical framework informed by the situated cognition learning theory. During this exploration, I explicitly described my decision-making process as I developed and revised a hypothetical learning progression. Correspondingly, my research question was: What is a process by which a hypothetical learning progression on sea level rise is developed into an empirical learning progression using learners' explanations? To answer this question, I used a qualitative descriptive single case study with multiple embedded cases (Yin, 2014) that employed analytic induction (Denzin, 1970) to analyze data collected on middle school learners (grades 6-8). Data sources included written artifacts, classroom observations, and semi-structured interviews. Additionally, I kept a researcher journal to track my thinking about the learning progression throughout the research study. Using analytic induction to analyze collected data, I developed eight analytic concepts: participant explanation structures varied widely, global warming and ice melt cause sea level rise, participants held alternative conceptions about sea level rise, participants learned about thermal expansion as a fundamental aspect of sea level rise, participants learned to incorporate authentic scientific data, participants' mental models of the ocean varied widely, sea ice melt contributes to sea level rise, and participants held vague and alternative conceptions about how pollution impacts the ocean. I started with a hypothetical learning progression, gathered empirical data via various sources (especially semi-structured interviews), revised the hypothetical learning progression in response to those data, and ended with an empirical learning progression comprising six levels of learner thinking. As a result of developing an empirically based LP, I was able to compare two learning progressions on the same topic. By comparing my learning progression with the LP in Breslyn, McGinnis, McDonald, and Hestness (2016), I was able to confirm portions of the two learning progressions and explore different possible pathways for learners to achieve progress towards upper anchors of the LPs through targeted instruction. Implications for future LP research, curriculum, instruction, assessment, and policy related to learning progressions are presented.

Universal antifungal therapy is not needed in persistent febrile neutropenia: a tailored diagnostic and therapeutic approach

PubMed Central

Aguilar-Guisado, Manuela; Martín-Peña, Almudena; Espigado, Ildefonso; Ruiz Pérez de Pipaon, Maite; Falantes, José; de la Cruz, Fátima; Cisneros, José M.

2012-01-01

Background Giving antifungal therapy exclusively to selected patients with persistent febrile neutropenia may avoid over-treatment without increasing mortality. The aim of this study was to validate an innovative diagnostic and therapeutic approach based on assessing patients’ risk profile and clinical criteria in order to select those patients requiring antifungal therapy. The efficacy of this approach was compared to that of universal empirical antifungal therapy. Design and Methods This was a prospective study which included all consecutive adult hematology patients with neutropenia and fever refractory to 5 days of empirical antibacterial therapy admitted to a teaching hospital in Spain over a 2-year period. A diagnostic and therapeutic approach based on clinical criteria and risk profile was applied in order to select patients for antifungal therapy. The sensitivity, specificity and negative predictive value of this approach and also the overall success rate, according to the same criteria of efficacy described in classical clinical trials, were analyzed. Results Eighty-five episodes were included, 35 of them (41.2%) in patients at high risk of invasive fungal infections. Antifungal therapy was not indicated in 33 episodes (38.8%). The overall incidence of proven and probable invasive fungal infections was 14.1%, all of which occurred in patients who had received empirical antifungal therapy. The 30-day crude mortality rate was 15.3% and the invasive fungal infection-related mortality rate was 2.8% (2/72). The overall success rate following the diagnostic and therapeutic approach was 36.5% compared with 33.9% and 33.7% obtained in the trial by Walsh et al. The sensitivity, specificity and negative predictive value of the study approach were 100%, 52.4% and 100%, respectively. Conclusions Based on the high negative predictive value of this diagnostic and therapeutic approach in persistent febrile neutropenia patients with hematologic malignancies or patients who have received a hematopoietic stem cell transplant, the approach is useful for identifying patients who are not likely to develop invasive fungal infection and do not, therefore, require antifungal therapy. The effectiveness of the strategy is similar to that of universal empirical antifungal therapy reported in controlled trials. PMID:22058202

Effects of temperature on consumer-resource interactions.

PubMed

Amarasekare, Priyanga

2015-05-01

Understanding how temperature variation influences the negative (e.g. self-limitation) and positive (e.g. saturating functional responses) feedback processes that characterize consumer-resource interactions is an important research priority. Previous work on this topic has yielded conflicting outcomes with some studies predicting that warming should increase consumer-resource oscillations and others predicting that warming should decrease consumer-resource oscillations. Here, I develop a consumer-resource model that both synthesizes previous findings in a common framework and yields novel insights about temperature effects on consumer-resource dynamics. I report three key findings. First, when the resource species' birth rate exhibits a unimodal temperature response, as demonstrated by a large number of empirical studies, the temperature range over which the consumer-resource interaction can persist is determined by the lower and upper temperature limits to the resource species' reproduction. This contrasts with the predictions of previous studies, which assume that the birth rate exhibits a monotonic temperature response, that consumer extinction is determined by temperature effects on consumer species' traits, rather than the resource species' traits. Secondly, the comparative analysis I have conducted shows that whether warming leads to an increase or decrease in consumer-resource oscillations depends on the manner in which temperature affects intraspecific competition. When the strength of self-limitation increases monotonically with temperature, warming causes a decrease in consumer-resource oscillations. However, if self-limitation is strongest at temperatures physiologically optimal for reproduction, a scenario previously unanalysed by theory but amply substantiated by empirical data, warming can cause an increase in consumer-resource oscillations. Thirdly, the model yields testable comparative predictions about consumer-resource dynamics under alternative hypotheses for how temperature affects competitive and resource acquisition traits. Importantly, it does so through empirically quantifiable metrics for predicting temperature effects on consumer viability and consumer-resource oscillations, which obviates the need for parameterizing complex dynamical models. Tests of these metrics with empirical data on a host-parasitoid interaction yield realistic estimates of temperature limits for consumer persistence and the propensity for consumer-resource oscillations, highlighting their utility in predicting temperature effects, particularly warming, on consumer-resource interactions in both natural and agricultural settings. © 2014 The Author. Journal of Animal Ecology © 2014 British Ecological Society.

Evapotranspiration Calculations for an Alpine Marsh Meadow Site in Three-river Headwater Region

NASA Astrophysics Data System (ADS)

Zhou, B.; Xiao, H.

2016-12-01

Daily radiation and meteorological data were collected at an alpine marsh meadow site in the Three-river Headwater Region(THR). Use them to assess radiation models determined after comparing the performance between Zuo model and the model recommend by FAO56P-M.Four methods, FAO56P-M, Priestley-Taylor, Hargreaves, and Makkink methods were applied to determine daily reference evapotranspiration( ETr) for the growing season and built the empirical models for estimating daily actual evapotranspiration ETa between ETr derived from the four methods and evapotranspiration derived from Bowen Ratio method on alpine marsh meadow in this region. After comparing the performance of four empirical models by RMSE, MAE and AI, it showed these models all can get the better estimated daily ETaon alpine marsh meadow in this region, and the best performance of the FAO56 P-M, Makkink empirical model were better than Priestley-Taylor and Hargreaves model.

Kernel-Smoothing Estimation of Item Characteristic Functions for Continuous Personality Items: An Empirical Comparison with the Linear and the Continuous-Response Models

ERIC Educational Resources Information Center

Ferrando, Pere J.

2004-01-01

This study used kernel-smoothing procedures to estimate the item characteristic functions (ICFs) of a set of continuous personality items. The nonparametric ICFs were compared with the ICFs estimated (a) by the linear model and (b) by Samejima's continuous-response model. The study was based on a conditioned approach and used an error-in-variables…

The Effect of Instructional Use of an iPad[R] on Challenging Behavior and Academic Engagement for Two Students with Autism

ERIC Educational Resources Information Center

Neely, Leslie; Rispoli, Mandy; Camargo, Siglia; Davis, Heather; Boles, Margot

2013-01-01

iPads[R] are increasingly used in the education of children with autism spectrum disorder. However, few empirical studies have examined the effects of iPads[R] on student behaviors. The purpose of this study was to compare academic instruction delivered with an iPad[R] to instruction delivered through traditional materials for two students with…

Comparison of Methods for Adjusting Incorrect Assignments of Items to Subtests: Oblique Multiple Group Method versus Confirmatory Common Factor Method

ERIC Educational Resources Information Center

Stuive, Ilse; Kiers, Henk A. L.; Timmerman, Marieke E.

2009-01-01

A common question in test evaluation is whether an a priori assignment of items to subtests is supported by empirical data. If the analysis results indicate the assignment of items to subtests under study is not supported by data, the assignment is often adjusted. In this study the authors compare two methods on the quality of their suggestions to…

Status Concern and Relative Deprivation in China: Measures, Empirical Evidence and Economic and Policy Implications

PubMed Central

Xi, CHEN

2017-01-01

Status concern and feelings of relative deprivation affect individual behaviour and well-being. Traditional norms and the alarming inequality in China have made relative deprivation increasingly intense for the Chinese population. This article reviews empirical literature on China that attempts to test the relative deprivation hypothesis, and also reviews the origins and pathways of relative deprivation, compares its economic measures in the literature and summarises the scientific findings. Drawing from solid empirical evidence, the author discusses the important policy implications on redistribution, official regulations and grassroots sanctions, and relative poverty alleviation. PMID:29033479

Status Concern and Relative Deprivation in China: Measures, Empirical Evidence and Economic and Policy Implications.

PubMed

Xi, Chen

2016-02-01

Status concern and feelings of relative deprivation affect individual behaviour and well-being. Traditional norms and the alarming inequality in China have made relative deprivation increasingly intense for the Chinese population. This article reviews empirical literature on China that attempts to test the relative deprivation hypothesis, and also reviews the origins and pathways of relative deprivation, compares its economic measures in the literature and summarises the scientific findings. Drawing from solid empirical evidence, the author discusses the important policy implications on redistribution, official regulations and grassroots sanctions, and relative poverty alleviation.

Comparison of cefepime versus ceftriaxone-amikacin as empirical regimens for the treatment of febrile neutropenia in acute leukemia patients.

PubMed

Borbolla, J R; López-Hernández, M A; González-Avante, M; DeDiego, J; Trueba, E; Alvarado, M L; Jiménez, R M

2001-01-01

High-intensity regimes of chemotherapy have led to longer and more severe episodes of neutropenia with a resulting increase in morbidity and mortality due to infections. Which empiric antibiotic regimen to use in these cases is still under debate. We performed a randomized comparative study to evaluate the efficacy of cefepime versus ceftriaxone plus amikacin as the initial treatment in an escalating, empirical, antibiotic therapy regimen in febrile neutropenic patients. Both adults and children were included. All patients had less than 500 neutrophils/microl at the time of infection. Patients were randomized to receive either cefepime or ceftriaxone plus amikacin. If infection continued 72 h later, patients in both groups received vancomycin, and if infection had not disappeared 7 days after starting antibiotics, amphotericin B was started. Twenty patients were included in each group. Both treatment and control groups were comparable for age and sex, among other factors. There were 18 cures in the cefepime group and 17 in the ceftriaxone plus amikacin group (p = 0.9). No patient discontinued therapy because of toxicity. Cefepime is a safe and very effective therapy for patients with acute leukemia and febrile neutropenia; in addition, it is a cheaper regimen in our country, and lacks the potential toxicity of the aminoglycosides. Copyright 2001 S. Karger AG, Basel

Adult bacterial meningitis: aetiology, penicillin susceptibility, risk factors, prognostic factors and guidelines for empirical antibiotic treatment.

PubMed

Meyer, C N; Samuelsson, I S; Galle, M; Bangsborg, J M

2004-08-01

Episodes of adult bacterial meningitis (ABM) at a Danish hospital in 1991-2000 were identified from the databases of the Department of Clinical Microbiology, and compared with data from the Danish National Patient Register and the Danish National Notification System. Reduced penicillin susceptibility occurred in 21 (23%) of 92 cases of known aetiology, compared to an estimated 6% in nationally notified cases (p < 0.001). Ceftriaxone plus penicillin as empirical treatment was appropriate in 97% of ABM cases in the study population, and in 99.6% of nationally notified cases. The notification rate was 75% for penicillin-susceptible episodes, and 24% for penicillin-non-susceptible episodes (p < 0.001). Cases involving staphylococci, Pseudomonas spp. and Enterobacteriaceae were under-reported. Among 51 ABM cases with no identified risk factors, nine of 11 cases with penicillin-non-susceptible bacteria were community-acquired. Severe sequelae correlated independently with age, penicillin non-susceptibility, mechanical ventilation and non-transferral to a tertiary hospital (p < 0.05; logistic regression). Other factors that correlated with severe sequelae by univariate analysis only were inappropriate clinical handling, abnormal consciousness, convulsions and nosocomial infection. Overall, the data indicated that neither age alone, community-acquired infection nor absence of identified risk factors can predict susceptibility to penicillin accurately. Recommendations for empirical antibiotic treatment for ABM should not be based exclusively on clinical notification systems with possible unbalanced under-reporting.

Multiscale Characterization of PM2.5 in Southern Taiwan based on Noise-assisted Multivariate Empirical Mode Decomposition and Time-dependent Intrinsic Correlation

NASA Astrophysics Data System (ADS)

Hsiao, Y. R.; Tsai, C.

2017-12-01

As the WHO Air Quality Guideline indicates, ambient air pollution exposes world populations under threat of fatal symptoms (e.g. heart disease, lung cancer, asthma etc.), raising concerns of air pollution sources and relative factors. This study presents a novel approach to investigating the multiscale variations of PM2.5 in southern Taiwan over the past decade, with four meteorological influencing factors (Temperature, relative humidity, precipitation and wind speed),based on Noise-assisted Multivariate Empirical Mode Decomposition(NAMEMD) algorithm, Hilbert Spectral Analysis(HSA) and Time-dependent Intrinsic Correlation(TDIC) method. NAMEMD algorithm is a fully data-driven approach designed for nonlinear and nonstationary multivariate signals, and is performed to decompose multivariate signals into a collection of channels of Intrinsic Mode Functions (IMFs). TDIC method is an EMD-based method using a set of sliding window sizes to quantify localized correlation coefficients for multiscale signals. With the alignment property and quasi-dyadic filter bank of NAMEMD algorithm, one is able to produce same number of IMFs for all variables and estimates the cross correlation in a more accurate way. The performance of spectral representation of NAMEMD-HSA method is compared with Complementary Empirical Mode Decomposition/ Hilbert Spectral Analysis (CEEMD-HSA) and Wavelet Analysis. The nature of NAMAMD-based TDICC analysis is then compared with CEEMD-based TDIC analysis and the traditional correlation analysis.

Identifying Conditions That Support Causal Inference in Observational Studies in Education: Empirical Evidence from within Study Comparisons

ERIC Educational Resources Information Center

Hallberg, Kelly

2013-01-01

This dissertation is a collection of three papers that employ empirical within study comparisons (WSCs) to identify conditions that support causal inference in observational studies. WSC studies empirically estimate the extent to which a given observational study reproduces the result of a randomized clinical trial (RCT) when both share the same…

Community-acquired Pseudomonas aeruginosa urinary tract infections in children hospitalized in a tertiary center: relative frequency, risk factors, antimicrobial resistance and treatment.

PubMed

Marcus, N; Ashkenazi, S; Samra, Z; Cohen, A; Livni, G

2008-10-01

The practice of antibiotic prophylaxis against recurrent urinary tract infection (UTI), with hospitalization reserved for severe or complicated cases, has led to changes in the nature and culprit uropathogens of community-acquired (CA), hospital-treated UTI. Characterization of subgroups that need special considerations is crucial. To elucidate the trends and characteristics of CA Pseudomonas UTI in hospitalized children; define the antibiotic susceptibility; determine the appropriateness of the empiric antibiotics used; compare to other causes of UTI in this population; and thereby define predictors for Pseudomonas UTI. A prospective clinical and laboratory study from 2001 through 2005. Children with P. aeruginosa UTI were characterized and compared with non-Pseudomonas UTI. Of 351 episodes of culture-proven CA UTI, 28 (8%) were caused by Pseudomonas, representing a 2.8-fold increase from our previous study. Pseudomonas UTI was more common in children > 5 years (p < 0.01), with urinary abnormalities (p < 0.01) and with previous antibiotic use in the previous month (p < 0.001). Pseudomonas UTI was often resistant to antibiotics usually recommended for empiric therapy; 25% was initially treated with inappropriate IV antibiotics (4.6% in the non-Pseudomonas group, p < 0.001) with 1.3 days longer IV antibiotics. On multivariate analysis, risk factors for Pseudomonas UTI were previous antibiotic therapy and underlying urinary pathology. Pseudomonas UTI seems to increase in CA, hospital-treated children and is often treated inappropriately according to current treatment protocols. Awareness of this trend and knowledge of the defined risk factors of Pseudomonas UTI might improve the empiric antibiotic therapy.

An empirical model to forecast solar wind velocity through statistical modeling

NASA Astrophysics Data System (ADS)

Gao, Y.; Ridley, A. J.

2013-12-01

The accurate prediction of the solar wind velocity has been a major challenge in the space weather community. Previous studies proposed many empirical and semi-empirical models to forecast the solar wind velocity based on either the historical observations, e.g. the persistence model, or the instantaneous observations of the sun, e.g. the Wang-Sheeley-Arge model. In this study, we use the one-minute WIND data from January 1995 to August 2012 to investigate and compare the performances of 4 models often used in literature, here referred to as the null model, the persistence model, the one-solar-rotation-ago model, and the Wang-Sheeley-Arge model. It is found that, measured by root mean square error, the persistence model gives the most accurate predictions within two days. Beyond two days, the Wang-Sheeley-Arge model serves as the best model, though it only slightly outperforms the null model and the one-solar-rotation-ago model. Finally, we apply the least-square regression to linearly combine the null model, the persistence model, and the one-solar-rotation-ago model to propose a 'general persistence model'. By comparing its performance against the 4 aforementioned models, it is found that the accuracy of the general persistence model outperforms the other 4 models within five days. Due to its great simplicity and superb performance, we believe that the general persistence model can serve as a benchmark in the forecast of solar wind velocity and has the potential to be modified to arrive at better models.

Markov modeling and discrete event simulation in health care: a systematic comparison.

PubMed

Standfield, Lachlan; Comans, Tracy; Scuffham, Paul

2014-04-01

The aim of this study was to assess if the use of Markov modeling (MM) or discrete event simulation (DES) for cost-effectiveness analysis (CEA) may alter healthcare resource allocation decisions. A systematic literature search and review of empirical and non-empirical studies comparing MM and DES techniques used in the CEA of healthcare technologies was conducted. Twenty-two pertinent publications were identified. Two publications compared MM and DES models empirically, one presented a conceptual DES and MM, two described a DES consensus guideline, and seventeen drew comparisons between MM and DES through the authors' experience. The primary advantages described for DES over MM were the ability to model queuing for limited resources, capture individual patient histories, accommodate complexity and uncertainty, represent time flexibly, model competing risks, and accommodate multiple events simultaneously. The disadvantages of DES over MM were the potential for model overspecification, increased data requirements, specialized expensive software, and increased model development, validation, and computational time. Where individual patient history is an important driver of future events an individual patient simulation technique like DES may be preferred over MM. Where supply shortages, subsequent queuing, and diversion of patients through other pathways in the healthcare system are likely to be drivers of cost-effectiveness, DES modeling methods may provide decision makers with more accurate information on which to base resource allocation decisions. Where these are not major features of the cost-effectiveness question, MM remains an efficient, easily validated, parsimonious, and accurate method of determining the cost-effectiveness of new healthcare interventions.

Impact of Company Size on Manufacturing Improvement Practices: An empirical study

NASA Astrophysics Data System (ADS)

Syan, C. S.; Ramoutar, K.

2014-07-01

There is a constant search for ways to achieve a competitive advantage through new manufacturing techniques. Best performing manufacturing companies tend to use world-class manufacturing (WCM) practices. Although the last few years have witnessed phenomenal growth in the use of WCM techniques, their effectiveness is not well understood specifically in the context of less developed countries. This paper presents an empirical study to investigate the impact of company size on improving manufacturing performance in manufacturing organizations based in Trinidad and Tobago (T&T). Empirical data were collected via a questionnaire survey which was send to 218 manufacturing firms in T&T. Five different company sizes and seven different industry sectors were studied. The analysis of survey data was performed with the aid of Statistical Package for Social Sciences (SPSS) software. The study signified facilitating and impeding factors towards improving manufacturing performance. Their relative impact/importance is dependent on varying company size and industry sectors. Findings indicate that T&T manufacturers are still practicing traditional approaches, when compared with world class manufacturers. In the majority of organizations, these practices were not 100% implemented even though they started the implementation process more than 5 years ago. The findings provided some insights in formulating more optimal operational strategies, and later develop action plans towards more effective implementation of WCM in T&T manufacturers.

Large wood influence on stream metabolism at a reach-scale in the Assabet River, Massachusetts

NASA Astrophysics Data System (ADS)

David, G. C. L.; Snyder, N. P.; Rosario, G. M.

2016-12-01

Total stream metabolism (TSM) represents the transfer of carbon through a channel by both primary production and respiration, and thus represents the movement of energy through a watershed. Large wood (LW) creates geomorphically complex channels by diverting flows, altering shear stresses on the channel bed and banks, and pool development. The increase in habitat complexity around LW is expected to increase TSM, but this change has not been directly measured. In this study, we measured changes in TSM around a LW jam in a Massachusetts river. Dissolved oxygen (DO) time series data are used to quantify gross primary production (GPP), ecosystem respiration (ER), which equal TSM when summed. Two primary objectives of this study are to (1) assess changes in TSM around LW and (2) compare empirical methods of deriving TSM to Grace et al.'s (2015) BASE model. We hypothesized that LW would increase TSM by providing larger pools, increasing coverage for fish and macroinvertebrates, increasing organic matter accumulation, and providing a place for primary producers to anchor and grow. The Assabet River is a 78 km2 drainage basin in central Massachusetts that provides public water supply to 7 towns. A change in TSM over a reach-scale was assessed using two YSI 6-Series Multiparameter Water Quality sondes over a 140 m long pool-riffle open meadow section. The reach included 6 pools and one LW jam. Every two weeks from July to November 2015, the sondes were moved to different pools. The sondes collected DO, temperature, depth, pH, salinity, light intensity, and turbidity at 15-minute intervals. Velocity (V) and discharge (Q) were measured weekly around the sondes and at established cross sections. Instantaneous V and Q were calculated for each sonde by modeling flows in HEC-RAS. Overall, TSM was heavily influenced by the pool size and indirectly to the LW jam which was associated with the largest pool. The largest error in TSM calculations is related to the empirically calculated reaeration flux (k), which represents oxygen inputs from the atmosphere. We used two well-established empirical equations to compare k values to the BASE model. The model agreed with empirically derived values during intermediate and high Q. Modeled GPP and ER diverged, sometimes by an order of magnitude, from the empirically derived results during the lowest flows.

Replacing Old Spatial Empires of the Mind: Rethinking Space and Place through Network Spatiality

ERIC Educational Resources Information Center

Beech, Jason; Larsen, Marianne A.

2014-01-01

In this article we argue for the spatialization of research on educational transfer in the field of comparative education within a theoretical framework that focuses on networks, connections, and flows. We present what we call a "spatial empire of the mind," which is comprised of a set of taken-for-granted "truths" about space…

A comparison of empirical and modeled nitrogen critical loads for Mediterranean forests and shrublands in California

Treesearch

M.E. Fenn; H.-D. Nagel; I. Koseva; J. Aherne; S.E. Jovan; L.H. Geiser; A. Schlutow; T. Scheuschner; A. Bytnerowicz; B.S. Gimeno; F. Yuan; S.A. Watmough; E.B. Allen; R.F. Johnson; T. Meixner

2014-01-01

Nitrogen (N) deposition is impacting a number of ecosystem types in California. Critical loads (CLs) for N deposition determined for mixed conifer forests and chaparral/oak woodlands in the Sierra Nevada Mountains of California and the San Bernardino Mountains in southern California using empirical and various modelling approaches were compared. Models used included...

Do Biology Students Really Hate Math? Empirical Insights into Undergraduate Life Science Majors' Emotions about Mathematics

ERIC Educational Resources Information Center

Wachsmuth, Lucas P.; Runyon, Christopher R.; Drake, John M.; Dolan, Erin L.

2017-01-01

Undergraduate life science majors are reputed to have negative emotions toward mathematics, yet little empirical evidence supports this. We sought to compare emotions of majors in the life sciences versus other natural sciences and math. We adapted the Attitudes toward the Subject of Chemistry Inventory to create an Attitudes toward the Subject of…

Semi-empirical calculations for the ranges of fast ions in silicon

NASA Astrophysics Data System (ADS)

Belkova, Yu. A.; Teplova, Ya. A.

2018-04-01

A semi-empirical method is proposed to calculate the ion ranges in energy region E = 0.025-10 MeV/nucleon. The dependence of ion ranges on the projectile nuclear charge, mass and velocity is analysed. The calculations presented for ranges of ions with nuclear charges Z = 2-10 in silicon are compared with SRIM results and experimental data.