Parent and Friend Social Support and Adolescent Hope.
Mahon, Noreen E; Yarcheski, Adela
2017-04-01
The purpose of this study was to conduct two meta-analyses. The first examined social support from parents in relation to adolescent hope, and the second examined social support from friends in relation to adolescent hope. Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for the literature reviewed, nine published studies or doctoral dissertations completed between 1990 and 2014 met the inclusion criteria. Using meta-analytic techniques and the mean weighted r statistic, the results indicated that social support from friends had a stronger mean effect size (ES = .31) than social support from parents (ES = .21); there was a statistically significant difference between the two ESs. Two of the four moderators for the parent social support-adolescent hope relationship were statistically significant. They were quality score and health status. Implications for school nurses and nurses in all settings are addressed, and conclusions are drawn based on the findings.
DESIGNING ENVIRONMENTAL MONITORING DATABASES FOR STATISTIC ASSESSMENT
Databases designed for statistical analyses have characteristics that distinguish them from databases intended for general use. EMAP uses a probabilistic sampling design to collect data to produce statistical assessments of environmental conditions. In addition to supporting the ...
In analyses supporting the development of numeric nutrient criteria, multiple statistical techniques can be used to extract critical values from stressor response relationships. However there is little guidance for choosing among techniques, and the extent to which log-transfor...
[Statistical analysis using freely-available "EZR (Easy R)" software].
Kanda, Yoshinobu
2015-10-01
Clinicians must often perform statistical analyses for purposes such evaluating preexisting evidence and designing or executing clinical studies. R is a free software environment for statistical computing. R supports many statistical analysis functions, but does not incorporate a statistical graphical user interface (GUI). The R commander provides an easy-to-use basic-statistics GUI for R. However, the statistical function of the R commander is limited, especially in the field of biostatistics. Therefore, the author added several important statistical functions to the R commander and named it "EZR (Easy R)", which is now being distributed on the following website: http://www.jichi.ac.jp/saitama-sct/. EZR allows the application of statistical functions that are frequently used in clinical studies, such as survival analyses, including competing risk analyses and the use of time-dependent covariates and so on, by point-and-click access. In addition, by saving the script automatically created by EZR, users can learn R script writing, maintain the traceability of the analysis, and assure that the statistical process is overseen by a supervisor.
Wallach, Joshua D; Sullivan, Patrick G; Trepanowski, John F; Sainani, Kristin L; Steyerberg, Ewout W; Ioannidis, John P A
2017-04-01
Many published randomized clinical trials (RCTs) make claims for subgroup differences. To evaluate how often subgroup claims reported in the abstracts of RCTs are actually supported by statistical evidence (P < .05 from an interaction test) and corroborated by subsequent RCTs and meta-analyses. This meta-epidemiological survey examines data sets of trials with at least 1 subgroup claim, including Subgroup Analysis of Trials Is Rarely Easy (SATIRE) articles and Discontinuation of Randomized Trials (DISCO) articles. We used Scopus (updated July 2016) to search for English-language articles citing each of the eligible index articles with at least 1 subgroup finding in the abstract. Articles with a subgroup claim in the abstract with or without evidence of statistical heterogeneity (P < .05 from an interaction test) in the text and articles attempting to corroborate the subgroup findings. Study characteristics of trials with at least 1 subgroup claim in the abstract were recorded. Two reviewers extracted the data necessary to calculate subgroup-level effect sizes, standard errors, and the P values for interaction. For individual RCTs and meta-analyses that attempted to corroborate the subgroup findings from the index articles, trial characteristics were extracted. Cochran Q test was used to reevaluate heterogeneity with the data from all available trials. The number of subgroup claims in the abstracts of RCTs, the number of subgroup claims in the abstracts of RCTs with statistical support (subgroup findings), and the number of subgroup findings corroborated by subsequent RCTs and meta-analyses. Sixty-four eligible RCTs made a total of 117 subgroup claims in their abstracts. Of these 117 claims, only 46 (39.3%) in 33 articles had evidence of statistically significant heterogeneity from a test for interaction. In addition, out of these 46 subgroup findings, only 16 (34.8%) ensured balance between randomization groups within the subgroups (eg, through stratified randomization), 13 (28.3%) entailed a prespecified subgroup analysis, and 1 (2.2%) was adjusted for multiple testing. Only 5 (10.9%) of the 46 subgroup findings had at least 1 subsequent pure corroboration attempt by a meta-analysis or an RCT. In all 5 cases, the corroboration attempts found no evidence of a statistically significant subgroup effect. In addition, all effect sizes from meta-analyses were attenuated toward the null. A minority of subgroup claims made in the abstracts of RCTs are supported by their own data (ie, a significant interaction effect). For those that have statistical support (P < .05 from an interaction test), most fail to meet other best practices for subgroup tests, including prespecification, stratified randomization, and adjustment for multiple testing. Attempts to corroborate statistically significant subgroup differences are rare; when done, the initially observed subgroup differences are not reproduced.
Torres-Carvajal, Omar; Schulte, James A; Cadle, John E
2006-04-01
The South American iguanian lizard genus Stenocercus includes 54 species occurring mostly in the Andes and adjacent lowland areas from northern Venezuela and Colombia to central Argentina at elevations of 0-4000m. Small taxon or character sampling has characterized all phylogenetic analyses of Stenocercus, which has long been recognized as sister taxon to the Tropidurus Group. In this study, we use mtDNA sequence data to perform phylogenetic analyses that include 32 species of Stenocercus and 12 outgroup taxa. Monophyly of this genus is strongly supported by maximum parsimony and Bayesian analyses. Evolutionary relationships within Stenocercus are further analyzed with a Bayesian implementation of a general mixture model, which accommodates variability in the pattern of evolution across sites. These analyses indicate a basal split of Stenocercus into two clades, one of which receives very strong statistical support. In addition, we test previous hypotheses using non-parametric and parametric statistical methods, and provide a phylogenetic classification for Stenocercus.
WAIS-IV Subtest Covariance Structure: Conceptual and Statistical Considerations
ERIC Educational Resources Information Center
Ward, L. Charles; Bergman, Maria A.; Hebert, Katina R.
2012-01-01
D. Wechsler (2008b) reported confirmatory factor analyses (CFAs) with standardization data (ages 16-69 years) for 10 core and 5 supplemental subtests from the Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV). Analyses of the 15 subtests supported 4 hypothesized oblique factors (Verbal Comprehension, Working Memory, Perceptual Reasoning,…
NASA Technical Reports Server (NTRS)
Young, M.; Koslovsky, M.; Schaefer, Caroline M.; Feiveson, A. H.
2017-01-01
Back by popular demand, the JSC Biostatistics Laboratory and LSAH statisticians are offering an opportunity to discuss your statistical challenges and needs. Take the opportunity to meet the individuals offering expert statistical support to the JSC community. Join us for an informal conversation about any questions you may have encountered with issues of experimental design, analysis, or data visualization. Get answers to common questions about sample size, repeated measures, statistical assumptions, missing data, multiple testing, time-to-event data, and when to trust the results of your analyses.
2014-01-01
Objective To offer a practical demonstration of receiver operating characteristic (ROC) analyses, diagnostic efficiency statistics, and their application to clinical decision making using a popular parent checklist to assess for potential mood disorder. Method Secondary analyses of data from 589 families seeking outpatient mental health services, completing the Child Behavior Checklist and semi-structured diagnostic interviews. Results Internalizing Problems raw scores discriminated mood disorders significantly better than did age- and gender-normed T scores, or an Affective Problems score. Internalizing scores <8 had a diagnostic likelihood ratio <0.3, and scores >30 had a diagnostic likelihood ratio of 7.4. Conclusions This study illustrates a series of steps in defining a clinical problem, operationalizing it, selecting a valid study design, and using ROC analyses to generate statistics that support clinical decisions. The ROC framework offers important advantages for clinical interpretation. Appendices include sample scripts using SPSS and R to check assumptions and conduct ROC analyses. PMID:23965298
Youngstrom, Eric A
2014-03-01
To offer a practical demonstration of receiver operating characteristic (ROC) analyses, diagnostic efficiency statistics, and their application to clinical decision making using a popular parent checklist to assess for potential mood disorder. Secondary analyses of data from 589 families seeking outpatient mental health services, completing the Child Behavior Checklist and semi-structured diagnostic interviews. Internalizing Problems raw scores discriminated mood disorders significantly better than did age- and gender-normed T scores, or an Affective Problems score. Internalizing scores <8 had a diagnostic likelihood ratio <0.3, and scores >30 had a diagnostic likelihood ratio of 7.4. This study illustrates a series of steps in defining a clinical problem, operationalizing it, selecting a valid study design, and using ROC analyses to generate statistics that support clinical decisions. The ROC framework offers important advantages for clinical interpretation. Appendices include sample scripts using SPSS and R to check assumptions and conduct ROC analyses.
Rainfall Results of the Florida Area Cumulus Experiment, 1970-76.
NASA Astrophysics Data System (ADS)
Woodley, William L.; Jordan, Jill; Barnston, Anthony; Simpson, Joanne; Biondini, Ron; Flueck, John
1982-02-01
The Florida Area Cumulus Experiment of 1970-76 (FACE-1) is a single-area, randomized, exploratory experiment to determine whether seeding cumuli for dynamic effects (dynamic seeding) can be used to augment convective rainfall over a substantial target area (1.3 × 104 km2) in south Florida. Rainfall is estimated using S-band radar observations after adjustment by raingages. The two primary response variables are rain volumes in the total target (TT) and in the floating target (FT), the most intensely treated portion of the target. The experimental unit is the day and the main observational period is the 6 h after initiation of treatment (silver iodide flares on seed days and either no flares or placebos on control days). Analyses without predictors suggest apparent increases in both the location (means and medians) and the dispersion (standard deviation and interquartile range) characteristics of rainfall due to seeding in the FT and TT variables with substantial statistical support for the FT results and lesser statistical support for the TT results. Analyses of covariance using meteorologically meaningful predictor variables suggest a somewhat larger effect of seeding with stronger statistical support. These results are interpreted in terms of the FACE conceptual model.
Niclasen, Janni; Keilow, Maria; Obel, Carsten
2018-05-01
Well-being is considered a prerequisite for learning. The Danish Ministry of Education initiated the development of a new 40-item student well-being questionnaire in 2014 to monitor well-being among all Danish public school students on a yearly basis. The aim of this study was to investigate the basic psychometric properties of this questionnaire. We used the data from the 2015 Danish student well-being survey for 268,357 students in grades 4-9 (about 85% of the study population). Descriptive statistics, exploratory factor analyses, confirmatory factor analyses and Cronbach's α reliability measures were used in the analyses. The factor analyses did not unambiguously support one particular factor structure. However, based on the basic descriptive statistics, exploratory factor analyses, confirmatory factor analyses, the semantics of the individual items and Cronbach's α, we propose a four-factor structure including 27 of the 40 items originally proposed. The four scales measure school connectedness, learning self-efficacy, learning environment and classroom management. Two bullying items and two psychosomatic items should be considered separately, leaving 31 items in the questionnaire. The proposed four-factor structure addresses central aspects of well-being, which, if used constructively, may support public schools' work to increase levels of student well-being.
Measurement issues in research on social support and health.
Dean, K; Holst, E; Kreiner, S; Schoenborn, C; Wilson, R
1994-01-01
STUDY OBJECTIVE--The aims were: (1) to identify methodological problems that may explain the inconsistencies and contradictions in the research evidence on social support and health, and (2) to validate a frequently used measure of social support in order to determine whether or not it could be used in multivariate analyses of population data in research on social support and health. DESIGN AND METHODS--Secondary analysis of data collected in a cross sectional survey of a multistage cluster sample of the population of the United States, designed to study relationships in behavioural, social support and health variables. Statistical models based on item response theory and graph theory were used to validate the measure of social support to be used in subsequent analyses. PARTICIPANTS--Data on 1755 men and women aged 20 to 64 years were available for the scale validation. RESULTS--Massive evidence of item bias was found for all items of a group membership subscale. The most serious problems were found in relationship to an item measuring membership in work related groups. Using that item in the social network scale in multivariate analyses would distort findings on the statistical effects of education, employment status, and household income. Evidence of item bias was also found for a sociability subscale. When marital status was included to create what is called an intimate contacts subscale, the confounding grew worse. CONCLUSIONS--The composite measure of social network is not valid and would seriously distort the findings of analyses attempting to study relationships between the index and other variables. The findings show that valid measurement is a methodological issue that must be addressed in scientific research on population health. PMID:8189179
Reframing Serial Murder Within Empirical Research.
Gurian, Elizabeth A
2017-04-01
Empirical research on serial murder is limited due to the lack of consensus on a definition, the continued use of primarily descriptive statistics, and linkage to popular culture depictions. These limitations also inhibit our understanding of these offenders and affect credibility in the field of research. Therefore, this comprehensive overview of a sample of 508 cases (738 total offenders, including partnered groups of two or more offenders) provides analyses of solo male, solo female, and partnered serial killers to elucidate statistical differences and similarities in offending and adjudication patterns among the three groups. This analysis of serial homicide offenders not only supports previous research on offending patterns present in the serial homicide literature but also reveals that empirically based analyses can enhance our understanding beyond traditional case studies and descriptive statistics. Further research based on these empirical analyses can aid in the development of more accurate classifications and definitions of serial murderers.
NASA Astrophysics Data System (ADS)
Berliner, M.
2017-12-01
Bayesian statistical decision theory offers a natural framework for decision-policy making in the presence of uncertainty. Key advantages of the approach include efficient incorporation of information and observations. However, in complicated settings it is very difficult, perhaps essentially impossible, to formalize the mathematical inputs needed in the approach. Nevertheless, using the approach as a template is useful for decision support; that is, organizing and communicating our analyses. Bayesian hierarchical modeling is valuable in quantifying and managing uncertainty such cases. I review some aspects of the idea emphasizing statistical model development and use in the context of sea-level rise.
The Development of a Decision Support System for Mobile Learning: A Case Study in Taiwan
ERIC Educational Resources Information Center
Chiu, Po-Sheng; Huang, Yueh-Min
2016-01-01
While mobile learning (m-learning) has considerable potential, most of previous strategies for developing this new approach to education were analysed using the knowledge, experience and judgement of individuals, with the support of statistical software. Although these methods provide systematic steps for the implementation of m-learning…
Siddall, James; Huebner, E Scott; Jiang, Xu
2013-01-01
This study examined the cross-sectional and prospective relationships between three sources of school-related social support (parent involvement, peer support for learning, and teacher-student relationships) and early adolescents' global life satisfaction. The participants were 597 middle school students from 1 large school in the southeastern United States who completed measures of school social climate and life satisfaction on 2 occasions, 5 months apart. The results revealed that school-related experiences in terms of social support for learning contributed substantial amounts of variance to individual differences in adolescents' satisfaction with their lives as a whole. Cross-sectional multiple regression analyses of the differential contributions of the sources of support demonstrated that family and peer support for learning contributed statistically significant, unique variance to global life satisfaction reports. Prospective multiple regression analyses demonstrated that only family support for learning continued to contribute statistically significant, unique variance to the global life satisfaction reports at Time 2. The results suggest that school-related experiences, especially family-school interactions, spill over into adolescents' overall evaluations of their lives at a time when direct parental involvement in schooling and adolescents' global life satisfaction are generally declining. Recommendations for future research and educational policies and practices are discussed. © 2013 American Orthopsychiatric Association.
An Exploratory Data Analysis System for Support in Medical Decision-Making
Copeland, J. A.; Hamel, B.; Bourne, J. R.
1979-01-01
An experimental system was developed to allow retrieval and analysis of data collected during a study of neurobehavioral correlates of renal disease. After retrieving data organized in a relational data base, simple bivariate statistics of parametric and nonparametric nature could be conducted. An “exploratory” mode in which the system provided guidance in selection of appropriate statistical analyses was also available to the user. The system traversed a decision tree using the inherent qualities of the data (e.g., the identity and number of patients, tests, and time epochs) to search for the appropriate analyses to employ.
Tonelli, Adriano R.; Zein, Joe; Adams, Jacob; Ioannidis, John P.A.
2014-01-01
Purpose Multiple interventions have been tested in acute respiratory distress syndrome (ARDS). We examined the entire agenda of published randomized controlled trials (RCTs) in ARDS that reported on mortality and of respective meta-analyses. Methods We searched PubMed, the Cochrane Library and Web of Knowledge until July 2013. We included RCTs in ARDS published in English. We excluded trials of newborns and children; and those on short-term interventions, ARDS prevention or post-traumatic lung injury. We also reviewed all meta-analyses of RCTs in this field that addressed mortality. Treatment modalities were grouped in five categories: mechanical ventilation strategies and respiratory care, enteral or parenteral therapies, inhaled / intratracheal medications, nutritional support and hemodynamic monitoring. Results We identified 159 published RCTs of which 93 had overall mortality reported (n= 20,671 patients) - 44 trials (14,426 patients) reported mortality as a primary outcome. A statistically significant survival benefit was observed in 8 trials (7 interventions) and two trials reported an adverse effect on survival. Among RTCs with >50 deaths in at least 1 treatment arm (n=21), 2 showed a statistically significant mortality benefit of the intervention (lower tidal volumes and prone positioning), 1 showed a statistically significant mortality benefit only in adjusted analyses (cisatracurium) and 1 (high-frequency oscillatory ventilation) showed a significant detrimental effect. Across 29 meta-analyses, the most consistent evidence was seen for low tidal volumes and prone positioning in severe ARDS. Conclusions There is limited supportive evidence that specific interventions can decrease mortality in ARDS. While low tidal volumes and prone positioning in severe ARDS seem effective, most sporadic findings of interventions suggesting reduced mortality are not corroborated consistently in large-scale evidence including meta-analyses. PMID:24667919
The Development of Statistics Textbook Supported with ICT and Portfolio-Based Assessment
NASA Astrophysics Data System (ADS)
Hendikawati, Putriaji; Yuni Arini, Florentina
2016-02-01
This research was development research that aimed to develop and produce a Statistics textbook model that supported with information and communication technology (ICT) and Portfolio-Based Assessment. This book was designed for students of mathematics at the college to improve students’ ability in mathematical connection and communication. There were three stages in this research i.e. define, design, and develop. The textbooks consisted of 10 chapters which each chapter contains introduction, core materials and include examples and exercises. The textbook developed phase begins with the early stages of designed the book (draft 1) which then validated by experts. Revision of draft 1 produced draft 2 which then limited test for readability test book. Furthermore, revision of draft 2 produced textbook draft 3 which simulated on a small sample to produce a valid model textbook. The data were analysed with descriptive statistics. The analysis showed that the Statistics textbook model that supported with ICT and Portfolio-Based Assessment valid and fill up the criteria of practicality.
ERIC Educational Resources Information Center
Bursal, Murat
2017-01-01
This study was conducted to investigate the academic achievement and perceived peer support levels of 4th-8th grade Turkish elementary and middle school students at low socio-economic status. Factorial design analyses were used to test the statistical effects of gender and preschool education variables on the dependent variables. The findings…
Quasi-Static Probabilistic Structural Analyses Process and Criteria
NASA Technical Reports Server (NTRS)
Goldberg, B.; Verderaime, V.
1999-01-01
Current deterministic structural methods are easily applied to substructures and components, and analysts have built great design insights and confidence in them over the years. However, deterministic methods cannot support systems risk analyses, and it was recently reported that deterministic treatment of statistical data is inconsistent with error propagation laws that can result in unevenly conservative structural predictions. Assuming non-nal distributions and using statistical data formats throughout prevailing stress deterministic processes lead to a safety factor in statistical format, which integrated into the safety index, provides a safety factor and first order reliability relationship. The embedded safety factor in the safety index expression allows a historically based risk to be determined and verified over a variety of quasi-static metallic substructures consistent with the traditional safety factor methods and NASA Std. 5001 criteria.
NASA Technical Reports Server (NTRS)
Feiveson, Alan H.; Foy, Millennia; Ploutz-Snyder, Robert; Fiedler, James
2014-01-01
Do you have elevated p-values? Is the data analysis process getting you down? Do you experience anxiety when you need to respond to criticism of statistical methods in your manuscript? You may be suffering from Insufficient Statistical Support Syndrome (ISSS). For symptomatic relief of ISSS, come for a free consultation with JSC biostatisticians at our help desk during the poster sessions at the HRP Investigators Workshop. Get answers to common questions about sample size, missing data, multiple testing, when to trust the results of your analyses and more. Side effects may include sudden loss of statistics anxiety, improved interpretation of your data, and increased confidence in your results.
Group cohesion and social support of the nurses in a special unit and a general unit in Korea.
Ko, Yu Kyung
2011-07-01
To identify the degree of group cohesion and social support of nurses in special and general units in hospitals in Korea, and to compare group cohesion and social support between the two groups. The level of commitment nurses have to their organizations has been shown to correlate with work group cohesion and social support. The participants were 1751 nurses who were working in Korean hospitals. Data were collected using a structured questionnaire and were analysed using SAS. The statistical methods included: descriptive statistics, t-test, anova and Pearson's correlation coefficients. Group cohesion of nurses on special wards was significantly higher than for nurses on general wards. No significant difference was found between types of units in terms of social support. The degree of group cohesion was significantly different in terms of the respondents' clinical experience, position, religion, job satisfaction, number of supportive superiors and number of supportive peers. A statistically significant correlation was found between group cohesion scores and degree of social support. Hospital management can accomplish their goals more effectively through knowledge of the level of group cohesion, superior support and peer support for nursing staff in accordance with unit specialty. © 2011 The Author. Journal compilation © 2011 Blackwell Publishing Ltd.
ERIC Educational Resources Information Center
Vincent, Claudia G.; Swain-Bradway, Jessica; Tobin, Tary J.; May, Seth
2011-01-01
The goal of our study was to examine if school-wide positive behavior support implementation was associated with reductions in the discipline gap. We provided outcomes from descriptive and preliminary statistical analyses of three years of office discipline referral data from elementary schools engaged in school-wide positive behavior support…
SOCR Analyses - an Instructional Java Web-based Statistical Analysis Toolkit.
Chu, Annie; Cui, Jenny; Dinov, Ivo D
2009-03-01
The Statistical Online Computational Resource (SOCR) designs web-based tools for educational use in a variety of undergraduate courses (Dinov 2006). Several studies have demonstrated that these resources significantly improve students' motivation and learning experiences (Dinov et al. 2008). SOCR Analyses is a new component that concentrates on data modeling and analysis using parametric and non-parametric techniques supported with graphical model diagnostics. Currently implemented analyses include commonly used models in undergraduate statistics courses like linear models (Simple Linear Regression, Multiple Linear Regression, One-Way and Two-Way ANOVA). In addition, we implemented tests for sample comparisons, such as t-test in the parametric category; and Wilcoxon rank sum test, Kruskal-Wallis test, Friedman's test, in the non-parametric category. SOCR Analyses also include several hypothesis test models, such as Contingency tables, Friedman's test and Fisher's exact test.The code itself is open source (http://socr.googlecode.com/), hoping to contribute to the efforts of the statistical computing community. The code includes functionality for each specific analysis model and it has general utilities that can be applied in various statistical computing tasks. For example, concrete methods with API (Application Programming Interface) have been implemented in statistical summary, least square solutions of general linear models, rank calculations, etc. HTML interfaces, tutorials, source code, activities, and data are freely available via the web (www.SOCR.ucla.edu). Code examples for developers and demos for educators are provided on the SOCR Wiki website.In this article, the pedagogical utilization of the SOCR Analyses is discussed, as well as the underlying design framework. As the SOCR project is on-going and more functions and tools are being added to it, these resources are constantly improved. The reader is strongly encouraged to check the SOCR site for most updated information and newly added models.
Wartberg, Lutz; Kriston, Levente; Kammerl, Rudolf
2017-07-01
Internet Gaming Disorder (IGD) has been included in the current edition of the Diagnostic and Statistical Manual of Mental Disorders-Fifth Edition (DSM-5). In the present study, the relationship among social support, friends only known through the Internet, health-related quality of life, and IGD in adolescence was explored for the first time. For this purpose, 1,095 adolescents aged from 12 to 14 years were surveyed with a standardized questionnaire concerning IGD, self-perceived social support, proportion of friends only known through the Internet, and health-related quality of life. The authors conducted unpaired t-tests, a chi-square test, as well as correlation and logistic regression analyses. According to the statistical analyses, adolescents with IGD reported lower self-perceived social support, more friends only known through the Internet, and a lower health-related quality of life compared with the group without IGD. Both in bivariate and multivariate logistic regression models, statistically significant associations between IGD and male gender, a higher proportion of friends only known through the Internet, and a lower health-related quality of life (multivariate model: Nagelkerke's R 2 = 0.37) were revealed. Lower self-perceived social support was related to IGD in the bivariate model only. In summary, quality of life and social aspects seem to be important factors for IGD in adolescence and therefore should be incorporated in further (longitudinal) studies. The findings of the present survey may provide starting points for the development of prevention and intervention programs for adolescents affected by IGD.
2013-01-01
Background Population studies on end-of-life decisions have not been conducted in Cyprus. Our study aim was to evaluate the beliefs and attitudes of Greek Cypriots towards end-of-life issues regarding euthanasia and cremation. Methods A population-based telephone survey was conducted in Cyprus. One thousand randomly selected individuals from the population of Cyprus age 20 years or older were invited to participate. Beliefs and attitudes on end-of-life decisions were collected using an anonymous and validated questionnaire. Statistical analyses included cross-tabulations, Pearson’s chi-square tests and multivariable-adjusted logistic regression models. Results A total of 308 males and 689 females participated in the survey. About 70% of the respondents did not support euthanasia for people with incurable illness and/or elders with dementia when requested by them and 77% did not support euthanasia for people with incurable illness and/or elders with dementia when requested by relatives. Regarding cremation, 78% were against and only 14% reported being in favor. Further statistical analyses showed that male gender, being single and having reached higher educational level were factors positively associated with support for euthanasia in a statistically significant fashion. On the contrary, the more religiosity expressed by study participants, the less support they reported for euthanasia or cremation. Conclusions The vast majority of Greek Cypriots does not support euthanasia for people with incurable illness and/or elders with dementia and also do not support cremation. Certain demographic characteristics such as age and education have a positive influence towards attitudes for euthanasia and cremation, while religiosity exerts a strong negative influence on the above. Family bonding as well as social and cultural traditions may also play a role although not comprehensively evaluated in the current study. PMID:24060291
Televantos, Anastasios; Talias, Michael A; Charalambous, Marianna; Soteriades, Elpidoforos S
2013-09-23
Population studies on end-of-life decisions have not been conducted in Cyprus. Our study aim was to evaluate the beliefs and attitudes of Greek Cypriots towards end-of-life issues regarding euthanasia and cremation. A population-based telephone survey was conducted in Cyprus. One thousand randomly selected individuals from the population of Cyprus age 20 years or older were invited to participate. Beliefs and attitudes on end-of-life decisions were collected using an anonymous and validated questionnaire. Statistical analyses included cross-tabulations, Pearson's chi-square tests and multivariable-adjusted logistic regression models. A total of 308 males and 689 females participated in the survey. About 70% of the respondents did not support euthanasia for people with incurable illness and/or elders with dementia when requested by them and 77% did not support euthanasia for people with incurable illness and/or elders with dementia when requested by relatives. Regarding cremation, 78% were against and only 14% reported being in favor. Further statistical analyses showed that male gender, being single and having reached higher educational level were factors positively associated with support for euthanasia in a statistically significant fashion. On the contrary, the more religiosity expressed by study participants, the less support they reported for euthanasia or cremation. The vast majority of Greek Cypriots does not support euthanasia for people with incurable illness and/or elders with dementia and also do not support cremation. Certain demographic characteristics such as age and education have a positive influence towards attitudes for euthanasia and cremation, while religiosity exerts a strong negative influence on the above. Family bonding as well as social and cultural traditions may also play a role although not comprehensively evaluated in the current study.
Statistical Representations of Track Geometry : Volume II, Appendices.
DOT National Transportation Integrated Search
1980-03-31
This volume contains some of the more detailed data and analyses to support the results and conclusions reached in Volume I of this report. It is divided into appendixes lettered A through J. Appendix A defines a procedure for evaluating the statisti...
Acconcia, M C; Caretta, Q; Romeo, F; Borzi, M; Perrone, M A; Sergi, D; Chiarotti, F; Calabrese, C M; Sili Scavalli, A; Gaudio, C
2018-04-01
Intra-aortic balloon pump (IABP) is the device most commonly investigated in patients with cardiogenic shock (CS) complicating acute myocardial infarction (AMI). Recently meta-analyses on this topic showed opposite results: some complied with the actual guideline recommendations, while others did not, due to the presence of bias. We investigated the reasons for the discrepancy among meta-analyses and strategies employed to avoid the potential source of bias. Scientific databases were searched for meta-analyses of IABP support in AMI complicated by CS. The presence of clinical diversity, methodological diversity and statistical heterogeneity were analyzed. When we found clinical or methodological diversity, we reanalyzed the data by comparing the patients selected for homogeneous groups. When the fixed effect model was employed despite the presence of statistical heterogeneity, the meta-analysis was repeated adopting the random effect model, with the same estimator used in the original meta-analysis. Twelve meta-analysis were selected. Six meta-analyses of randomized controlled trials (RCTs) were inconclusive because underpowered to detect the IABP effect. Five included RCTs and observational studies (Obs) and one only Obs. Some meta-analyses on RCTs and Obs had biased results due to presence of clinical and/or methodological diversity. The reanalysis of data reallocated for homogeneous groups was no more in contrast with guidelines recommendations. Meta-analyses performed without controlling for clinical and/or methodological diversity, represent a confounding message against a good clinical practice. The reanalysis of data demonstrates the validity of the current guidelines recommendations in addressing clinical decision making in providing IABP support in AMI complicated by CS.
Nonnormality and Divergence in Posttreatment Alcohol Use
Witkiewitz, Katie; van der Maas, Han L. J.; Hufford, Michael R.; Marlatt, G. Alan
2007-01-01
Alcohol lapses are the modal outcome following treatment for alcohol use disorders, yet many alcohol researchers have encountered limited success in the prediction and prevention of relapse. One hypothesis is that lapses are unpredictable, but another possibility is the complexity of the relapse process is not captured by traditional statistical methods. Data from Project Matching Alcohol Treatments to Client Heterogeneity (Project MATCH), a multisite alcohol treatment study, were reanalyzed with 2 statistical methodologies: catastrophe and 2-part growth mixture modeling. Drawing on previous investigations of self-efficacy as a dynamic predictor of relapse, the current study revisits the self-efficacy matching hypothesis, which was not statistically supported in Project MATCH. Results from both the catastrophe and growth mixture analyses demonstrated a dynamic relationship between self-efficacy and drinking outcomes. The growth mixture analyses provided evidence in support of the original matching hypothesis: Individuals with lower self-efficacy who received cognitive behavior therapy drank far less frequently than did those with low self-efficacy who received motivational therapy. These results highlight the dynamical nature of the relapse process and the importance of the use of methodologies that accommodate this complexity when evaluating treatment outcomes. PMID:17516769
Subbaraman, Meenakshi Sabina; Kerr, William C.
2017-01-01
Background Support for the legalization of recreational marijuana continues to increase across the United States and globally. In 2016, recreational marijuana was legalized in the most populous US state of California, as well as three other states. The primary aim of this study was to examine trends in support for recreational marijuana legalization in Washington, a state which has had legal recreational marijuana for almost four years, using data collected over the four years post-legalization. A secondary aim was to examine trends in support for the cultivation of marijuana for personal use. Methods Data come from geographically representative general population samples of adult (aged 18 and over) Washington residents collected over five timepoints (every six months) between January 2014 and April 2016 (N = 4,101). Random Digit Dial was used for recruitment. Statistical analyses involved bivariate comparisons of proportions across timepoints and subgroups (defined by age, gender, and marijuana user status), and multivariable logistic regression controlling for timepoint (time) to formally test for trend while controlling for demographic and substance use covariates. All analyses adjusted for probability of selection. Results Support for legalization in Washington has significantly increased: support was 64.0% (95% CI: 61.2%–67.8%) at timepoint 1 and 77.9% (95% CI: 73.2%–81.9%) at timepoint 5. With each six months’ passing, support increased 19% on average. We found no statistically significant change in support for home-growing. Conclusions Support for marijuana legalization has continued to significantly increase in a state that has experienced the policy change for almost four years. PMID:28448904
Subbaraman, Meenakshi Sabina; Kerr, William C
2017-06-01
Support for the legalization of recreational marijuana continues to increase across the United States and globally. In 2016, recreational marijuana was legalized in the most populous US state of California, as well as three other states. The primary aim of this study was to examine trends in support for recreational marijuana legalization in Washington, a state which has had legal recreational marijuana for almost four years, using data collected over the four years post-legalization. A secondary aim was to examine trends in support for the cultivation of marijuana for personal use. Data come from geographically representative general population samples of adult (aged 18 and over) Washington residents collected over five timepoints (every six months) between January 2014 and April 2016 (N=4101). Random Digit Dial was used for recruitment. Statistical analyses involved bivariate comparisons of proportions across timepoints and subgroups (defined by age, gender, and marijuana user status), and multivariable logistic regression controlling for timepoint (time) to formally test for trend while controlling for demographic and substance use covariates. All analyses adjusted for probability of selection. Support for legalization in Washington has significantly increased: support was 64.0% (95% CI: 61.2%-67.8%) at timepoint 1 and 77.9% (95% CI: 73.2%-81.9%) at timepoint 5. With each six months' passing, support increased 19% on average. We found no statistically significant change in support for home-growing. Support for marijuana legalization has continued to significantly increase in a state that has experienced the policy change for almost four years. Copyright © 2017. Published by Elsevier B.V.
USDA-ARS?s Scientific Manuscript database
Phylogenetic analyses of species of Streptomyces based on 16S rRNA gene sequences resulted in a statistically well-supported clade (100% bootstrap value) containing 8 species having very similar gross morphology. These species, including Streptomyces bambergiensis, Streptomyces chlorus, Streptomyces...
Croft, Giles P; Williams, John G; Mann, Robin Y; Cohen, David; Phillips, Ceri J
2007-08-01
Hospital episode statistics were originally designed to monitor activity and allocate resources in the NHS. Recently their uses have widened to include analysis of individuals' activity, to inform appraisal and revalidation, and monitor performance. This study investigated physician attitudes to the validity and usefulness of these data for such purposes, and the effect of supporting individuals in data interpretation. A randomised study was conducted with consultant physicians in England, Wales and Scotland. The intervention group was supported by a clinician and an information analyst in obtaining and analysing their own data. The control group was unsupported. Attitudes to the data and confidence in their ability to reflect clinical practice were examined before and after the intervention. It was concluded that hospital episode statistics are not presently fit for monitoring the performance of individual physicians. A more comprehensive description of activity is required for these purposes. Improvements in the quality of existing data through clinical engagement at a local level, however, are possible.
Cano, Miguel Ángel; Sánchez, Mariana; Trepka, Mary Jo; Dillon, Frank R; Sheehan, Diana M; Rojas, Patria; Kanamori, Mariano J; Huang, Hui; Auf, Rehab; De La Rosa, Mario
2017-03-01
Identifying and understanding determinants of alcohol use behavior among Hispanic immigrants is an increasingly significant public health concern. Although prior research has examined associations of cultural stressors with alcohol use among Hispanics, few studies have tested these associations among recent adult immigrants. As such, this study aimed to examine (a) the association of immigration stress on alcohol use severity among recently immigrated Hispanic adults (≤ 1 year in the United States) and (b) the moderating effects of gender, immigration status, and social support. A hierarchical multiple regression and moderation analyses were conducted on a sample of 527 participants in South Florida. Results indicated that, after controlling for demographic variables, preimmigration drinking behavior, and dimensions of social support, the association of higher immigration stress with higher alcohol use severity was statistically significant. Moderation analyses indicated that immigration stress had a statistically significant association with alcohol use severity among men, but not women. Also, dimensions of social support consistently reduced the deleterious effect of immigration stress on alcohol use severity. This study adds to the scarce literature on cultural stressors and alcohol use among recent Hispanic immigrants. Findings suggest that it may be important to design gender-specific interventions and that increasing levels of social support may offset the effects of immigration stress on alcohol use. © 2016 Wiley Periodicals, Inc.
Customer perceived service quality, satisfaction and loyalty in Indian private healthcare.
Kondasani, Rama Koteswara Rao; Panda, Rajeev Kumar
2015-01-01
The purpose of this paper is to analyse how perceived service quality and customer satisfaction lead to loyalty towards healthcare service providers. In total, 475 hospital patients participated in a questionnaire survey in five Indian private hospitals. Descriptive statistics, factor analysis, regression and correlation statistics were employed to analyse customer perceived service quality and how it leads to loyalty towards service providers. Results indicate that the service seeker-service provider relationship, quality of facilities and the interaction with supporting staff have a positive effect on customer perception. Findings help healthcare managers to formulate effective strategies to ensure a better quality of services to the customers. This study helps healthcare managers to build customer loyalty towards healthcare services, thereby attracting and gaining more customers. This paper will help healthcare managers and service providers to analyse customer perceptions and their loyalty towards Indian private healthcare services.
Tanavalee, Chotetawan; Luksanapruksa, Panya; Singhatanadgige, Weerasak
2016-06-01
Microsoft Excel (MS Excel) is a commonly used program for data collection and statistical analysis in biomedical research. However, this program has many limitations, including fewer functions that can be used for analysis and a limited number of total cells compared with dedicated statistical programs. MS Excel cannot complete analyses with blank cells, and cells must be selected manually for analysis. In addition, it requires multiple steps of data transformation and formulas to plot survival analysis graphs, among others. The Megastat add-on program, which will be supported by MS Excel 2016 soon, would eliminate some limitations of using statistic formulas within MS Excel.
SOCR Analyses – an Instructional Java Web-based Statistical Analysis Toolkit
Chu, Annie; Cui, Jenny; Dinov, Ivo D.
2011-01-01
The Statistical Online Computational Resource (SOCR) designs web-based tools for educational use in a variety of undergraduate courses (Dinov 2006). Several studies have demonstrated that these resources significantly improve students' motivation and learning experiences (Dinov et al. 2008). SOCR Analyses is a new component that concentrates on data modeling and analysis using parametric and non-parametric techniques supported with graphical model diagnostics. Currently implemented analyses include commonly used models in undergraduate statistics courses like linear models (Simple Linear Regression, Multiple Linear Regression, One-Way and Two-Way ANOVA). In addition, we implemented tests for sample comparisons, such as t-test in the parametric category; and Wilcoxon rank sum test, Kruskal-Wallis test, Friedman's test, in the non-parametric category. SOCR Analyses also include several hypothesis test models, such as Contingency tables, Friedman's test and Fisher's exact test. The code itself is open source (http://socr.googlecode.com/), hoping to contribute to the efforts of the statistical computing community. The code includes functionality for each specific analysis model and it has general utilities that can be applied in various statistical computing tasks. For example, concrete methods with API (Application Programming Interface) have been implemented in statistical summary, least square solutions of general linear models, rank calculations, etc. HTML interfaces, tutorials, source code, activities, and data are freely available via the web (www.SOCR.ucla.edu). Code examples for developers and demos for educators are provided on the SOCR Wiki website. In this article, the pedagogical utilization of the SOCR Analyses is discussed, as well as the underlying design framework. As the SOCR project is on-going and more functions and tools are being added to it, these resources are constantly improved. The reader is strongly encouraged to check the SOCR site for most updated information and newly added models. PMID:21546994
Sensitivity analysis of static resistance of slender beam under bending
DOE Office of Scientific and Technical Information (OSTI.GOV)
Valeš, Jan
2016-06-08
The paper deals with statical and sensitivity analyses of resistance of simply supported I-beams under bending. The resistance was solved by geometrically nonlinear finite element method in the programme Ansys. The beams are modelled with initial geometrical imperfections following the first eigenmode of buckling. Imperfections were, together with geometrical characteristics of cross section, and material characteristics of steel, considered as random quantities. The method Latin Hypercube Sampling was applied to evaluate statistical and sensitivity resistance analyses.
ERIC Educational Resources Information Center
Lang, Quek Choon; Wong, Angela F. L.; Fraser, Barry J.
2005-01-01
This study investigated associations between teacher-student interaction and students' attitudes towards chemistry among 497 tenth grade students from three independent schools in Singapore. Analyses supported the reliability and validity of a 48-item version of the Questionnaire on Teacher Interaction (QTI). Statistically significant gender…
States-of-Mind Model: Cognitive Balance in the Treatment of Agoraphobia.
ERIC Educational Resources Information Center
Schwartz, Robert M.; Michelson, Larry
1987-01-01
Used states-of-mind model to track therapeutic changes in cognitive balance of 39 agoraphobics. Descriptive and statistical analyses from an outcome study of graduated exposure, relaxation training, and paradoxical intention supported the model. Agoraphobics evinced negative dialogue at pretreatment, positive dialogue at mid and posttreatment, and…
Seok, Soonhwa; DaCosta, Boaventura
2017-01-01
This study investigated relationships between digital propensity and support needs as well as predictors of digital propensity in the context of support intensity, age, gender, and social maturity. A total of 118 special education teachers rated the support intensity, digital propensity, and social maturity of 352 students with intellectual disability. Leveraging the Digital Propensity Index, Supports Intensity Scale, and the Social Maturity Scale, descriptive statistics, correlations, multiple regressions, and regression analyses were employed. The findings revealed significant relationships between digital propensity and support needs. In addition, significant predictors of digital propensity were found with regard to support intensity, age, gender, and social maturity.
Zeitz, Kathryn; Haghighi, Pari Delir; Burstein, Frada; Williams, Jeffrey
2013-06-01
The present study was designed to further understand the psychosocial drivers of crowds impacting on the demand for healthcare. This involved analysing different spectator crowds for medical usage at mass gatherings; more specifically, did different football team spectators (of the Australian Football League) generate different medical usage rates. In total, 317 games were analysed from 10 venues over 2 years. Data were analysed by the ANOVA and Pearson correlation tests. RESULTS; Spectators who supported different football teams generated statistically significant differences in patient presentation rates (PPR) (F15, 618=1.998, P=0.014). The present study confirmed previous findings that there is a positive correlation between the crowd size and PPR at mass gatherings but found a negative correlation between density and PPR (r = -0.206, n=317, P<0.0005). The present study has attempted to scientifically explore psychosocial elements of crowd behaviour as a driver of demand for emergency medical care. In measuring demand for emergency medical services there is a need to develop a more sophisticated understanding of a variety of drivers in addition to traditional metrics such as temperature, crowd size and other physical elements. In this study we saw that spectators who supported different football teams generated statistically significant differences in PPR. What is known about this topic? Understanding the drivers of emergency medical care is most important in the mass gathering setting. There has been minimal analysis of psychological 'crowd' variables. What does this paper add? This study explores the psychosocial impact of supporting a different team on the PPR of spectators at Australian Football League matches. The value of collecting and analysing these types of data sets is to support more balanced planning, better decision support and knowledge management, and more effective emergency medical demand management. What are the implications for practitioners? This information further expands the body of evidence being created to understand the drivers of emergency medical demand and usage. In addition, it supports the planning and management of emergency medical and health-related requirements by increasing our understanding of the effect of elements of 'crowd' that impact on medical usage and emergency healthcare.
Provision for Learners with Special Educational Needs in Botswana: A Situational Analysis
ERIC Educational Resources Information Center
Dart, Gareth
2007-01-01
This paper considers the support of children with special educational needs in Botswana. A variety of sources including policy documents, literature, statistical data, interviews with key personnel and observation, are used to analyse the context and delivery of provision. Botswana is a middle-income country that has seen rapid economic expansion…
Schoech, D; Quinn, A; Rycraft, J R
2000-01-01
Data mining is the sifting through of voluminous data to extract knowledge for decision making. This article illustrates the context, concepts, processes, techniques, and tools of data mining, using statistical and neural network analyses on a dataset concerning employee turnover. The resulting models and their predictive capability, advantages and disadvantages, and implications for decision support are highlighted.
A Comparison of Self versus Tutor Assessment among Hungarian Undergraduate Business Students
ERIC Educational Resources Information Center
Kun, András István
2016-01-01
This study analyses the self-assessment behaviour and efficiency of 163 undergraduate business students from Hungary. Using various statistical methods, the results support the hypothesis that high-achieving students are more accurate in their pre- and post-examination self-assessments, and also less likely to overestimate their performance, and,…
Ontario Universities Statistical Compendium, 1970-90. Part A: Micro-Indicators.
ERIC Educational Resources Information Center
Council of Ontario Universities, Toronto. Research Div.
This publication provides macro-indicators and complementary analyses and supporting data for use by policy and decision makers concerned with Ontario universities. These analytical tools are meant to unambiguously measure what is taking place in Canadian postsecondary education, and therefore, assist in focusing on what decisions need to be made.…
Open Doors 1991/92. Report on International Educational Exchange.
ERIC Educational Resources Information Center
Zikopoulos, Marianthi, Ed.; And Others
1992-01-01
This report provides statistical data on 419,600 foreign students from over 200 countries studying at U.S. higher educational institutions. The report identifies trends in student mobility and migration, national origin, sources of financial support, fields of study, enrollments, and rates of growth. The book's extensive tables and analyses are…
Nursing teams: behind the charts.
Bae, Sung-Heui; Farasat, Alireza; Nikolaev, Alex; Seo, Jin Young; Foltz-Ramos, Kelly; Fabry, Donna; Castner, Jessica
2017-07-01
To examine the nature and characteristics of both received and provided mutual support in a social network within an acute care hospital unit. Current evidence regarding the social network in the health care workforce reveals the nature of social ties. Most studies of social network-related support that measured the characteristics of social support used self-reported perception from workers receiving support. There is a gap in studies that focus on back-up behaviour. The evaluation included a social network analysis of a nursing unit employing 54 staff members. A 12 item electronic survey was administered. Descriptive statistics were calculated using the Statistical Package for the Social Sciences. Social network analyses were carried out using ucinet, r 3.2.3 and gephi. Based on the study findings, as providers of mutual support the nursing staff claimed to give their peers more help than these peers gave them credit for. Those who worked overtime provided more mutual support. Mutual support is a key teamwork characteristic, essential to quality and safety in hospital nursing teams that can be evaluated using social network analysis. Because of a discrepancy regarding receiving and providing help, examining both receiver and provider networks is a superior approach to understanding mutual support. © 2017 John Wiley & Sons Ltd.
Appraising the self-assessed support needs of Turkish women with breast cancer.
Erci, B; Karabulut, N
2007-03-01
The purposes of this study were to establish the range of needs of women with breast cancer and to examine how women's needs might form clusters that could provide the basis for developing a standardized scale of needs for use by local breast care nurses in the evaluation of care. The sample consisted of 143 women with breast cancer who were admitted to the outpatient and inpatient oncology clinics in a university hospital in Erzurum, Turkey. The data were collected by questionnaire, and included demographic characteristics and the self-assessed support needs of women with breast cancer. Statistical analyses have shown that the standardized scale of needs has statistically acceptable levels of reliability and validity. The women's support needs mostly clustered in Family and Friends (79%) and After Care (78.3%). The most frequently required support category was Family and Friend; however, the women were in need of support of all categories. In terms of age ranges, there are statistically significant differences in relation to Femininity and Body Image, and Family and Friends of the seven categories. Women experienced a high level of needs associated with a diagnosis of breast cancer. The results in this study should increase awareness among cancer care professionals about a range of psychosocial needs and may help them target particular patient groups for particular support interventions.
Body Weight Reducing Effect of Oral Boric Acid Intake
Aysan, Erhan; Sahin, Fikrettin; Telci, Dilek; Yalvac, Mehmet Emir; Emre, Sinem Hocaoglu; Karaca, Cetin; Muslumanoglu, Mahmut
2011-01-01
Background: Boric acid is widely used in biology, but its body weight reducing effect is not researched. Methods: Twenty mice were divided into two equal groups. Control group mice drank standard tap water, but study group mice drank 0.28mg/250ml boric acid added tap water over five days. Total body weight changes, major organ histopathology, blood biochemistry, urine and feces analyses were compared. Results: Study group mice lost body weight mean 28.1% but in control group no weight loss and also weight gained mean 0.09% (p<0.001). Total drinking water and urine outputs were not statistically different. Cholesterol, LDL, AST, ALT, LDH, amylase and urobilinogen levels were statistically significantly high in the study group. Other variables were not statistically different. No histopathologic differences were detected in evaluations of all resected major organs. Conclusion: Low dose oral boric acid intake cause serious body weight reduction. Blood and urine analyses support high glucose, lipid and middle protein catabolisms, but the mechanism is unclear. PMID:22135611
Body weight reducing effect of oral boric acid intake.
Aysan, Erhan; Sahin, Fikrettin; Telci, Dilek; Yalvac, Mehmet Emir; Emre, Sinem Hocaoglu; Karaca, Cetin; Muslumanoglu, Mahmut
2011-01-01
Boric acid is widely used in biology, but its body weight reducing effect is not researched. Twenty mice were divided into two equal groups. Control group mice drank standard tap water, but study group mice drank 0.28mg/250ml boric acid added tap water over five days. Total body weight changes, major organ histopathology, blood biochemistry, urine and feces analyses were compared. Study group mice lost body weight mean 28.1% but in control group no weight loss and also weight gained mean 0.09% (p<0.001). Total drinking water and urine outputs were not statistically different. Cholesterol, LDL, AST, ALT, LDH, amylase and urobilinogen levels were statistically significantly high in the study group. Other variables were not statistically different. No histopathologic differences were detected in evaluations of all resected major organs. Low dose oral boric acid intake cause serious body weight reduction. Blood and urine analyses support high glucose, lipid and middle protein catabolisms, but the mechanism is unclear.
Hu, Ting; Pan, Qinxin; Andrew, Angeline S; Langer, Jillian M; Cole, Michael D; Tomlinson, Craig R; Karagas, Margaret R; Moore, Jason H
2014-04-11
Several different genetic and environmental factors have been identified as independent risk factors for bladder cancer in population-based studies. Recent studies have turned to understanding the role of gene-gene and gene-environment interactions in determining risk. We previously developed the bioinformatics framework of statistical epistasis networks (SEN) to characterize the global structure of interacting genetic factors associated with a particular disease or clinical outcome. By applying SEN to a population-based study of bladder cancer among Caucasians in New Hampshire, we were able to identify a set of connected genetic factors with strong and significant interaction effects on bladder cancer susceptibility. To support our statistical findings using networks, in the present study, we performed pathway enrichment analyses on the set of genes identified using SEN, and found that they are associated with the carcinogen benzo[a]pyrene, a component of tobacco smoke. We further carried out an mRNA expression microarray experiment to validate statistical genetic interactions, and to determine if the set of genes identified in the SEN were differentially expressed in a normal bladder cell line and a bladder cancer cell line in the presence or absence of benzo[a]pyrene. Significant nonrandom sets of genes from the SEN were found to be differentially expressed in response to benzo[a]pyrene in both the normal bladder cells and the bladder cancer cells. In addition, the patterns of gene expression were significantly different between these two cell types. The enrichment analyses and the gene expression microarray results support the idea that SEN analysis of bladder in population-based studies is able to identify biologically meaningful statistical patterns. These results bring us a step closer to a systems genetic approach to understanding cancer susceptibility that integrates population and laboratory-based studies.
Hart, Corey B.; Giszter, Simon F.
2013-01-01
We present and apply a method that uses point process statistics to discriminate the forms of synergies in motor pattern data, prior to explicit synergy extraction. The method uses electromyogram (EMG) pulse peak timing or onset timing. Peak timing is preferable in complex patterns where pulse onsets may be overlapping. An interval statistic derived from the point processes of EMG peak timings distinguishes time-varying synergies from synchronous synergies (SS). Model data shows that the statistic is robust for most conditions. Its application to both frog hindlimb EMG and rat locomotion hindlimb EMG show data from these preparations is clearly most consistent with synchronous synergy models (p < 0.001). Additional direct tests of pulse and interval relations in frog data further bolster the support for synchronous synergy mechanisms in these data. Our method and analyses support separated control of rhythm and pattern of motor primitives, with the low level execution primitives comprising pulsed SS in both frog and rat, and both episodic and rhythmic behaviors. PMID:23675341
Ceballos-Laita, Laura; Gutierrez-Carbonell, Elain; Takahashi, Daisuke; Abadía, Anunciación; Uemura, Matsuo; Abadía, Javier; López-Millán, Ana Flor
2018-04-01
This article contains consolidated proteomic data obtained from xylem sap collected from tomato plants grown in Fe- and Mn-sufficient control, as well as Fe-deficient and Mn-deficient conditions. Data presented here cover proteins identified and quantified by shotgun proteomics and Progenesis LC-MS analyses: proteins identified with at least two peptides and showing changes statistically significant (ANOVA; p ≤ 0.05) and above a biologically relevant selected threshold (fold ≥ 2) between treatments are listed. The comparison between Fe-deficient, Mn-deficient and control xylem sap samples using a multivariate statistical data analysis (Principal Component Analysis, PCA) is also included. Data included in this article are discussed in depth in the research article entitled "Effects of Fe and Mn deficiencies on the protein profiles of tomato ( Solanum lycopersicum) xylem sap as revealed by shotgun analyses" [1]. This dataset is made available to support the cited study as well to extend analyses at a later stage.
Khallad, Yacoub; Jabr, Fares
2016-10-01
The effects of perceived social support and family demands on college students' mental well-being (perceived stress and depression) were assessed in 2 samples of Jordanian and Turkish college students. Statistically significant negative correlations were found between perceived support and mental well-being. Multiple regression analyses showed that perceived family support was a better predictor of mental well-being for Jordanian students, while perceived support from friends was a better predictor of mental well-being for Turkish students. Perceived family demands were stronger predictors of mental well-being for participants from both ethnic groups. Jordanian and Turkish participants who perceived their families to be too demanding were more likely to report higher depression and stress levels. None of the interactions between social support or family demands and either of the 2 demographic variables were statistically significant. These findings provide a more nuanced view of the relationship between social support and mental health among college students, and point to the relevance of some cultural and situational factors. They also draw further attention to the detrimental effects of unrealistic family demands and pressures on the mental health of college youths. © 2015 International Union of Psychological Science.
Understanding evaluation of learning support in mathematics and statistics
NASA Astrophysics Data System (ADS)
MacGillivray, Helen; Croft, Tony
2011-03-01
With rapid and continuing growth of learning support initiatives in mathematics and statistics found in many parts of the world, and with the likelihood that this trend will continue, there is a need to ensure that robust and coherent measures are in place to evaluate the effectiveness of these initiatives. The nature of learning support brings challenges for measurement and analysis of its effects. After briefly reviewing the purpose, rationale for, and extent of current provision, this article provides a framework for those working in learning support to think about how their efforts can be evaluated. It provides references and specific examples of how workers in this field are collecting, analysing and reporting their findings. The framework is used to structure evaluation in terms of usage of facilities, resources and services provided, and also in terms of improvements in performance of the students and staff who engage with them. Very recent developments have started to address the effects of learning support on the development of deeper approaches to learning, the affective domain and the development of communities of practice of both learners and teachers. This article intends to be a stimulus to those who work in mathematics and statistics support to gather even richer, more valuable, forms of data. It provides a 'toolkit' for those interested in evaluation of learning support and closes by referring to an on-line resource being developed to archive the growing body of evidence.
Shekhar, S; Yoo, E-H; Ahmed, S A; Haining, R; Kadannolly, S
2017-02-01
Spatial decision support systems have already proved their value in helping to reduce infectious diseases but to be effective they need to be designed to reflect local circumstances and local data availability. We report the first stage of a project to develop a spatial decision support system for infectious diseases for Karnataka State in India. The focus of this paper is on malaria incidence and we draw on small area data on new cases of malaria analysed in two-monthly time intervals over the period February 2012 to January 2016 for Kalaburagi taluk, a small area in Karnataka. We report the results of data mapping and cluster detection (identifying areas of excess risk) including evaluating the temporal persistence of excess risk and the local conditions with which high counts are statistically associated. We comment on how this work might feed into a practical spatial decision support system. Copyright © 2017 Elsevier Ltd. All rights reserved.
Turning the Potential Liability of Large Enrollment Laboratory Science Courses into an Asset
ERIC Educational Resources Information Center
Johnson, Dan; Levy, Foster; Karsai, Istvan; Stroud, Kimberly
2006-01-01
Data sharing among multiple lab sections increases statistical power of data analyses and informs student-generated hypotheses. We describe how to collect, organize, and manage data to support replicate and rolling inquiry models, with three illustrative examples of activities from a population-level biology course for science majors. (Contains 1…
Ontario Universities Statistical Compendium, 1970-71 to 1979-80. Part A, Macro-Indicators.
ERIC Educational Resources Information Center
Council of Ontario Universities, Toronto.
Macro-indicators concerning finances of Ontario universities for 1970-71 to 1979-80 are considered, along with supporting data that might be used to generate such indicators, and complementary analyses that might be used to enhance understanding of both indicators and data. Operating revenue in constant dollars has been identified per…
ERIC Educational Resources Information Center
King, Janet L.
2017-01-01
The utilization of learning analytics to support teaching and learning has emerged as a newer phenomenon combining instructor-oriented action research, the mining of educational data, and the analyses of statistics and patterns. Learning analytics have documented, quantified and graphically displayed students' interactions, engagement, and…
Ontario Universities Statistical Compendium, 1970-71 to 1978-79. Part A, Macro-Indicators.
ERIC Educational Resources Information Center
Council of Ontario Universities, Toronto.
Macro-indicators on the conditions of Ontario universities and supporting data that might be used to generate such indicators were developed, and analyses of both indicators and data were undertaken. Overall objectives were as follows: (1) to measure the real resources available to the Ontario university system as a function of the volume of…
USDA-ARS?s Scientific Manuscript database
Previous phylogenetic analyses of species of Streptomyces based on 16S rRNA gene sequences resulted in a statistically well-supported clade (100% bootstrap value) containing 8 species that exhibited very similar gross morphology in producing open looped (Retinaculum-Apertum) to spiral (Spira) chains...
2012-01-01
Background A statistical analysis plan (SAP) is a critical link between how a clinical trial is conducted and the clinical study report. To secure objective study results, regulatory bodies expect that the SAP will meet requirements in pre-specifying inferential analyses and other important statistical techniques. To write a good SAP for model-based sensitivity and ancillary analyses involves non-trivial decisions on and justification of many aspects of the chosen setting. In particular, trials with longitudinal count data as primary endpoints pose challenges for model choice and model validation. In the random effects setting, frequentist strategies for model assessment and model diagnosis are complex and not easily implemented and have several limitations. Therefore, it is of interest to explore Bayesian alternatives which provide the needed decision support to finalize a SAP. Methods We focus on generalized linear mixed models (GLMMs) for the analysis of longitudinal count data. A series of distributions with over- and under-dispersion is considered. Additionally, the structure of the variance components is modified. We perform a simulation study to investigate the discriminatory power of Bayesian tools for model criticism in different scenarios derived from the model setting. We apply the findings to the data from an open clinical trial on vertigo attacks. These data are seen as pilot data for an ongoing phase III trial. To fit GLMMs we use a novel Bayesian computational approach based on integrated nested Laplace approximations (INLAs). The INLA methodology enables the direct computation of leave-one-out predictive distributions. These distributions are crucial for Bayesian model assessment. We evaluate competing GLMMs for longitudinal count data according to the deviance information criterion (DIC) or probability integral transform (PIT), and by using proper scoring rules (e.g. the logarithmic score). Results The instruments under study provide excellent tools for preparing decisions within the SAP in a transparent way when structuring the primary analysis, sensitivity or ancillary analyses, and specific analyses for secondary endpoints. The mean logarithmic score and DIC discriminate well between different model scenarios. It becomes obvious that the naive choice of a conventional random effects Poisson model is often inappropriate for real-life count data. The findings are used to specify an appropriate mixed model employed in the sensitivity analyses of an ongoing phase III trial. Conclusions The proposed Bayesian methods are not only appealing for inference but notably provide a sophisticated insight into different aspects of model performance, such as forecast verification or calibration checks, and can be applied within the model selection process. The mean of the logarithmic score is a robust tool for model ranking and is not sensitive to sample size. Therefore, these Bayesian model selection techniques offer helpful decision support for shaping sensitivity and ancillary analyses in a statistical analysis plan of a clinical trial with longitudinal count data as the primary endpoint. PMID:22962944
Adrion, Christine; Mansmann, Ulrich
2012-09-10
A statistical analysis plan (SAP) is a critical link between how a clinical trial is conducted and the clinical study report. To secure objective study results, regulatory bodies expect that the SAP will meet requirements in pre-specifying inferential analyses and other important statistical techniques. To write a good SAP for model-based sensitivity and ancillary analyses involves non-trivial decisions on and justification of many aspects of the chosen setting. In particular, trials with longitudinal count data as primary endpoints pose challenges for model choice and model validation. In the random effects setting, frequentist strategies for model assessment and model diagnosis are complex and not easily implemented and have several limitations. Therefore, it is of interest to explore Bayesian alternatives which provide the needed decision support to finalize a SAP. We focus on generalized linear mixed models (GLMMs) for the analysis of longitudinal count data. A series of distributions with over- and under-dispersion is considered. Additionally, the structure of the variance components is modified. We perform a simulation study to investigate the discriminatory power of Bayesian tools for model criticism in different scenarios derived from the model setting. We apply the findings to the data from an open clinical trial on vertigo attacks. These data are seen as pilot data for an ongoing phase III trial. To fit GLMMs we use a novel Bayesian computational approach based on integrated nested Laplace approximations (INLAs). The INLA methodology enables the direct computation of leave-one-out predictive distributions. These distributions are crucial for Bayesian model assessment. We evaluate competing GLMMs for longitudinal count data according to the deviance information criterion (DIC) or probability integral transform (PIT), and by using proper scoring rules (e.g. the logarithmic score). The instruments under study provide excellent tools for preparing decisions within the SAP in a transparent way when structuring the primary analysis, sensitivity or ancillary analyses, and specific analyses for secondary endpoints. The mean logarithmic score and DIC discriminate well between different model scenarios. It becomes obvious that the naive choice of a conventional random effects Poisson model is often inappropriate for real-life count data. The findings are used to specify an appropriate mixed model employed in the sensitivity analyses of an ongoing phase III trial. The proposed Bayesian methods are not only appealing for inference but notably provide a sophisticated insight into different aspects of model performance, such as forecast verification or calibration checks, and can be applied within the model selection process. The mean of the logarithmic score is a robust tool for model ranking and is not sensitive to sample size. Therefore, these Bayesian model selection techniques offer helpful decision support for shaping sensitivity and ancillary analyses in a statistical analysis plan of a clinical trial with longitudinal count data as the primary endpoint.
NASA Astrophysics Data System (ADS)
Miranda, Susan Jennifer
A mixed methods approach was used to identify factors that influence the underrepresentation of Latinos in the domain of science. The researcher investigated the role of family influences, academic preparation, and personal motivations to determine science-related career choices by Latinos. Binary logistic regression analyses were conducted using information from Latinos gathered from the National Education Longitudinal Study of 1988 (NELS: 88) administered by the National Center for Education Statistics. For the present study, data were analyzed using participants' responses as high school seniors, college students, and post-baccalaureates. Students responded to questions on school, work, parental academic influences, personal aspirations, and self-perception. To provide more insight into the experiences of Latinos in science and support the statistical analyses, nine students majoring in science in a private, urban university located in the northeastern part of the country were interviewed. Eleven variables related to parents' academic support and students' perceptions of parental support were taken together as predictors for two separate criteria from the survey. These results identified parents' level of education and the importance of academics to parents in their teen's college choice as significant predictors in determining college major in science. When the criterion was degree in science, the significant predictor was the frequency parents contacted high school as volunteers. Student interviews supported this information, demonstrating the importance of parental support in attaining a degree in science. Academic preparation was also analyzed. Students' reasons for taking science classes in high school was a significant predictor for science major; significant predictors for science degree were the emphasis placed on objectives in math and science classes and number of courses in biology and physics. Student interviews supported this information and demonstrated the influence their own motivation placed on their goals. Survey data were also obtained about the students' test scores and academic achievement. Data collected from the statistical and interview components of the study developed a greater understanding for the lack of Latinos in the sciences as influenced by personal and familial factors.
Views of medical students: what, when and how do they want statistics taught?
Fielding, S; Poobalan, A; Prescott, G J; Marais, D; Aucott, L
2015-11-01
A key skill for a practising clinician is being able to do research, understand the statistical analyses and interpret results in the medical literature. Basic statistics has become essential within medical education, but when, what and in which format is uncertain. To inform curriculum design/development we undertook a quantitative survey of fifth year medical students and followed them up with a series of focus groups to obtain their opinions as to what statistics teaching they want, when and how. A total of 145 students undertook the survey and five focus groups were held with between 3 and 9 participants each. Previous statistical training varied and students recognised their knowledge was inadequate and keen to see additional training implemented. Students were aware of the importance of statistics to their future careers, but apprehensive about learning. Face-to-face teaching supported by online resources was popular. Focus groups indicated the need for statistical training early in their degree and highlighted their lack of confidence and inconsistencies in support. The study found that the students see the importance of statistics training in the medical curriculum but that timing and mode of delivery are key. The findings have informed the design of a new course to be implemented in the third undergraduate year. Teaching will be based around published studies aiming to equip students with the basics required with additional resources available through a virtual learning environment. © The Author(s) 2015.
ERIC Educational Resources Information Center
National Association of Independent Colleges and Universities, Washington, DC.
This report seeks to explain the complex relationship between "cost" and "price" at independent private colleges and universities, and to demonstrate that federal student financial aid does not contribute to tuition and fee increases at such institutions. To support these results, 10 facts, drawn from multivariate statistical analyses of data from…
ERIC Educational Resources Information Center
Biggar, Ronald S.; Hoehn, James B.
The National Science Survey of Scientific Activities of Institutions of Higher Education, the subject of this report, is designed to provide national statistics that cast light on these issues. Through analyses of the data, a better picture is purported to be produced on the impact of Federal policy in support of scientific endeavors. The report…
Nagy, László G; Urban, Alexander; Orstadius, Leif; Papp, Tamás; Larsson, Ellen; Vágvölgyi, Csaba
2010-12-01
Recently developed comparative phylogenetic methods offer a wide spectrum of applications in evolutionary biology, although it is generally accepted that their statistical properties are incompletely known. Here, we examine and compare the statistical power of the ML and Bayesian methods with regard to selection of best-fit models of fruiting-body evolution and hypothesis testing of ancestral states on a real-life data set of a physiological trait (autodigestion) in the family Psathyrellaceae. Our phylogenies are based on the first multigene data set generated for the family. Two different coding regimes (binary and multistate) and two data sets differing in taxon sampling density are examined. The Bayesian method outperformed Maximum Likelihood with regard to statistical power in all analyses. This is particularly evident if the signal in the data is weak, i.e. in cases when the ML approach does not provide support to choose among competing hypotheses. Results based on binary and multistate coding differed only modestly, although it was evident that multistate analyses were less conclusive in all cases. It seems that increased taxon sampling density has favourable effects on inference of ancestral states, while model parameters are influenced to a smaller extent. The model best fitting our data implies that the rate of losses of deliquescence equals zero, although model selection in ML does not provide proper support to reject three of the four candidate models. The results also support the hypothesis that non-deliquescence (lack of autodigestion) has been ancestral in Psathyrellaceae, and that deliquescent fruiting bodies represent the preferred state, having evolved independently several times during evolution. Copyright © 2010 Elsevier Inc. All rights reserved.
msap: a tool for the statistical analysis of methylation-sensitive amplified polymorphism data.
Pérez-Figueroa, A
2013-05-01
In this study msap, an R package which analyses methylation-sensitive amplified polymorphism (MSAP or MS-AFLP) data is presented. The program provides a deep analysis of epigenetic variation starting from a binary data matrix indicating the banding pattern between the isoesquizomeric endonucleases HpaII and MspI, with differential sensitivity to cytosine methylation. After comparing the restriction fragments, the program determines if each fragment is susceptible to methylation (representative of epigenetic variation) or if there is no evidence of methylation (representative of genetic variation). The package provides, in a user-friendly command line interface, a pipeline of different analyses of the variation (genetic and epigenetic) among user-defined groups of samples, as well as the classification of the methylation occurrences in those groups. Statistical testing provides support to the analyses. A comprehensive report of the analyses and several useful plots could help researchers to assess the epigenetic and genetic variation in their MSAP experiments. msap is downloadable from CRAN (http://cran.r-project.org/) and its own webpage (http://msap.r-forge.R-project.org/). The package is intended to be easy to use even for those people unfamiliar with the R command line environment. Advanced users may take advantage of the available source code to adapt msap to more complex analyses. © 2013 Blackwell Publishing Ltd.
Varma, Rajesh; Gupta, Janesh K
2006-01-01
There is considerable evidence to show an association between genital tract infections, such as bacterial vaginosis (BV), and preterm delivery (PTD). Meta-analyses to date have shown screening and treating BV in pregnancy does not prevent PTD. This casts doubt on a cause and effect relationship between BV and PTD. However, the meta-analyses reported significant clinical, methodological and statistical heterogeneity of the included studies. We therefore undertook a repeat meta-analysis, included recently published trials, and applied strict criteria on data extraction. We meta-analysed low and high-risk pregnancies separately. We found that screening and treating BV in low-risk pregnancies produced a statistically significant reduction in spontaneous PTD (RR 0.73; 95% CI 0.55-0.98). This beneficial effect was not observed in high-risk or combined risk groups. The differences in antibiotic sensitivity between high and low risk groups may suggest differing causal contributions of the infectious process to PTD. The evidence, along with prior knowledge of differing predisposing factors and prognosis between these risk groups, supports the hypothesis that PTD in high and low risk pregnant women are different entities and not linear extremes of the same syndrome.
Structural Qualification of Composite Airframes
NASA Technical Reports Server (NTRS)
Kedward, Keith T.; McCarty, John E.
1997-01-01
The development of fundamental approaches for predicting failure and elongation characteristics of fibrous composites are summarized in this document. The research described includes a statistical formulation for individual fiber breakage and fragmentation and clustered fiber breakage, termed macrodefects wherein the aligned composite may represent a structural component such as a reinforcing bar element, a rebar. Experimental work conducted in support of the future exploitation of aligned composite rebar elements is also described. This work discusses the experimental challenges associated with rebar tensile test evaluation and describes initial numerical analyses performed in support of the experimental program.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kelly, Elizabeth J.; Dewart, Jean Marie; Deola, Regina
This report provides site-specific return level analyses for rain, snow, and straight-line wind extreme events. These analyses are in support of the 10-year review plan for the assessment of meteorological natural phenomena hazards at Los Alamos National Laboratory (LANL). These analyses follow guidance from Department of Energy, DOE Standard, Natural Phenomena Hazards Analysis and Design Criteria for DOE Facilities (DOE-STD-1020-2012), Nuclear Regulatory Commission Standard Review Plan (NUREG-0800, 2007) and ANSI/ ANS-2.3-2011, Estimating Tornado, Hurricane, and Extreme Straight-Line Wind Characteristics at Nuclear Facility Sites. LANL precipitation and snow level data have been collected since 1910, although not all years are complete.more » In this report the results from the more recent data (1990–2014) are compared to those of past analyses and a 2004 National Oceanographic and Atmospheric Administration report. Given the many differences in the data sets used in these different analyses, the lack of statistically significant differences in return level estimates increases confidence in the data and in the modeling and analysis approach.« less
Tice, Alexander K; Shadwick, Lora L; Fiore-Donno, Anna Maria; Geisen, Stefan; Kang, Seungho; Schuler, Gabriel A; Spiegel, Frederick W; Wilkinson, Katherine A; Bonkowski, Michael; Dumack, Kenneth; Lahr, Daniel J G; Voelcker, Eckhard; Clauß, Steffen; Zhang, Junling; Brown, Matthew W
2016-12-28
Acanthamoebidae is a "family" level amoebozoan group composed of the genera Acanthamoeba, Protacanthamoeba, and very recently Luapeleamoeba. This clade of amoebozoans has received considerable attention from the broader scientific community as Acanthamoeba spp. represent both model organisms and human pathogens. While the classical composition of the group (Acanthamoeba + Protacanthamoeba) has been well accepted due to the morphological and ultrastructural similarities of its members, the Acanthamoebidae has never been highly statistically supported in single gene phylogenetic reconstructions of Amoebozoa either by maximum likelihood (ML) or Bayesian analyses. Here we show using a phylogenomic approach that the Acanthamoebidae is a fully supported monophyletic group within Amoebozoa with both ML and Bayesian analyses. We also expand the known range of morphological and life cycle diversity found in the Acanthamoebidae by demonstrating that the amoebozoans "Protostelium" arachisporum, Dracoamoeba jormungandri n. g. n. sp., and Vacuolamoeba acanthoformis n.g. n.sp., belong within the group. We also found that "Protostelium" pyriformis is clearly a species of Acanthamoeba making it the first reported sporocarpic member of the genus, that is, an amoeba that individually forms a walled, dormant propagule elevated by a non-cellular stalk. Our phylogenetic analyses recover a fully supported Acanthamoebidae composed of five genera. Two of these genera (Acanthamoeba and Luapeleameoba) have members that are sporocarpic. Our results provide high statistical support for an Acanthamoebidae that is composed of five distinct genera. This study increases the known morphological diversity of this group and shows that species of Acanthamoeba can include spore-bearing stages. This further illustrates the widespread nature of spore-bearing stages across the tree of Amoebozoa. This article was reviewed by Drs. Eugene Koonin, Purificacion Lopez-Garcia and Sandra Baldauf. Sandra Baldauf was nominated by Purificacion Lopez-Garcia, an Editorial Board member.
Interpretation of correlations in clinical research.
Hung, Man; Bounsanga, Jerry; Voss, Maren Wright
2017-11-01
Critically analyzing research is a key skill in evidence-based practice and requires knowledge of research methods, results interpretation, and applications, all of which rely on a foundation based in statistics. Evidence-based practice makes high demands on trained medical professionals to interpret an ever-expanding array of research evidence. As clinical training emphasizes medical care rather than statistics, it is useful to review the basics of statistical methods and what they mean for interpreting clinical studies. We reviewed the basic concepts of correlational associations, violations of normality, unobserved variable bias, sample size, and alpha inflation. The foundations of causal inference were discussed and sound statistical analyses were examined. We discuss four ways in which correlational analysis is misused, including causal inference overreach, over-reliance on significance, alpha inflation, and sample size bias. Recent published studies in the medical field provide evidence of causal assertion overreach drawn from correlational findings. The findings present a primer on the assumptions and nature of correlational methods of analysis and urge clinicians to exercise appropriate caution as they critically analyze the evidence before them and evaluate evidence that supports practice. Critically analyzing new evidence requires statistical knowledge in addition to clinical knowledge. Studies can overstate relationships, expressing causal assertions when only correlational evidence is available. Failure to account for the effect of sample size in the analyses tends to overstate the importance of predictive variables. It is important not to overemphasize the statistical significance without consideration of effect size and whether differences could be considered clinically meaningful.
The Effect of Multispectral Image Fusion Enhancement on Human Efficiency
2017-03-20
performance of the ideal observer is indicative of the relative amount of informa- tion across various experimental manipulations. In our experimental design ...registration and fusion processes, and contributed strongly to the statistical analyses. LMB contributed to the experimental design and writing structure. All... designed to be innovative, low-cost, and (relatively) easy-to-implement, and to provide support across the spectrum of possible users including
Statistical universals reveal the structures and functions of human music.
Savage, Patrick E; Brown, Steven; Sakai, Emi; Currie, Thomas E
2015-07-21
Music has been called "the universal language of mankind." Although contemporary theories of music evolution often invoke various musical universals, the existence of such universals has been disputed for decades and has never been empirically demonstrated. Here we combine a music-classification scheme with statistical analyses, including phylogenetic comparative methods, to examine a well-sampled global set of 304 music recordings. Our analyses reveal no absolute universals but strong support for many statistical universals that are consistent across all nine geographic regions sampled. These universals include 18 musical features that are common individually as well as a network of 10 features that are commonly associated with one another. They span not only features related to pitch and rhythm that are often cited as putative universals but also rarely cited domains including performance style and social context. These cross-cultural structural regularities of human music may relate to roles in facilitating group coordination and cohesion, as exemplified by the universal tendency to sing, play percussion instruments, and dance to simple, repetitive music in groups. Our findings highlight the need for scientists studying music evolution to expand the range of musical cultures and musical features under consideration. The statistical universals we identified represent important candidates for future investigation.
Statistical universals reveal the structures and functions of human music
Savage, Patrick E.; Brown, Steven; Sakai, Emi; Currie, Thomas E.
2015-01-01
Music has been called “the universal language of mankind.” Although contemporary theories of music evolution often invoke various musical universals, the existence of such universals has been disputed for decades and has never been empirically demonstrated. Here we combine a music-classification scheme with statistical analyses, including phylogenetic comparative methods, to examine a well-sampled global set of 304 music recordings. Our analyses reveal no absolute universals but strong support for many statistical universals that are consistent across all nine geographic regions sampled. These universals include 18 musical features that are common individually as well as a network of 10 features that are commonly associated with one another. They span not only features related to pitch and rhythm that are often cited as putative universals but also rarely cited domains including performance style and social context. These cross-cultural structural regularities of human music may relate to roles in facilitating group coordination and cohesion, as exemplified by the universal tendency to sing, play percussion instruments, and dance to simple, repetitive music in groups. Our findings highlight the need for scientists studying music evolution to expand the range of musical cultures and musical features under consideration. The statistical universals we identified represent important candidates for future investigation. PMID:26124105
Replication Unreliability in Psychology: Elusive Phenomena or “Elusive” Statistical Power?
Tressoldi, Patrizio E.
2012-01-01
The focus of this paper is to analyze whether the unreliability of results related to certain controversial psychological phenomena may be a consequence of their low statistical power. Applying the Null Hypothesis Statistical Testing (NHST), still the widest used statistical approach, unreliability derives from the failure to refute the null hypothesis, in particular when exact or quasi-exact replications of experiments are carried out. Taking as example the results of meta-analyses related to four different controversial phenomena, subliminal semantic priming, incubation effect for problem solving, unconscious thought theory, and non-local perception, it was found that, except for semantic priming on categorization, the statistical power to detect the expected effect size (ES) of the typical study, is low or very low. The low power in most studies undermines the use of NHST to study phenomena with moderate or low ESs. We conclude by providing some suggestions on how to increase the statistical power or use different statistical approaches to help discriminate whether the results obtained may or may not be used to support or to refute the reality of a phenomenon with small ES. PMID:22783215
Olimpo, Jeffrey T.; Pevey, Ryan S.; McCabe, Thomas M.
2018-01-01
Course-based undergraduate research experiences (CUREs) provide an avenue for student participation in authentic scientific opportunities. Within the context of such coursework, students are often expected to collect, analyze, and evaluate data obtained from their own investigations. Yet, limited research has been conducted that examines mechanisms for supporting students in these endeavors. In this article, we discuss the development and evaluation of an interactive statistics workshop that was expressly designed to provide students with an open platform for graduate teaching assistant (GTA)-mentored data processing, statistical testing, and synthesis of their own research findings. Mixed methods analyses of pre/post-intervention survey data indicated a statistically significant increase in students’ reasoning and quantitative literacy abilities in the domain, as well as enhancement of student self-reported confidence in and knowledge of the application of various statistical metrics to real-world contexts. Collectively, these data reify an important role for scaffolded instruction in statistics in preparing emergent scientists to be data-savvy researchers in a globally expansive STEM workforce. PMID:29904549
Olimpo, Jeffrey T; Pevey, Ryan S; McCabe, Thomas M
2018-01-01
Course-based undergraduate research experiences (CUREs) provide an avenue for student participation in authentic scientific opportunities. Within the context of such coursework, students are often expected to collect, analyze, and evaluate data obtained from their own investigations. Yet, limited research has been conducted that examines mechanisms for supporting students in these endeavors. In this article, we discuss the development and evaluation of an interactive statistics workshop that was expressly designed to provide students with an open platform for graduate teaching assistant (GTA)-mentored data processing, statistical testing, and synthesis of their own research findings. Mixed methods analyses of pre/post-intervention survey data indicated a statistically significant increase in students' reasoning and quantitative literacy abilities in the domain, as well as enhancement of student self-reported confidence in and knowledge of the application of various statistical metrics to real-world contexts. Collectively, these data reify an important role for scaffolded instruction in statistics in preparing emergent scientists to be data-savvy researchers in a globally expansive STEM workforce.
NASA Astrophysics Data System (ADS)
Poulos, M. J.; Pierce, J. L.; McNamara, J. P.; Flores, A. N.; Benner, S. G.
2015-12-01
Terrain aspect alters the spatial distribution of insolation across topography, driving eco-pedo-hydro-geomorphic feedbacks that can alter landform evolution and result in valley asymmetries for a suite of land surface characteristics (e.g. slope length and steepness, vegetation, soil properties, and drainage development). Asymmetric valleys serve as natural laboratories for studying how landscapes respond to climate perturbation. In the semi-arid montane granodioritic terrain of the Idaho batholith, Northern Rocky Mountains, USA, prior works indicate that reduced insolation on northern (pole-facing) aspects prolongs snow pack persistence, and is associated with thicker, finer-grained soils, that retain more water, prolong the growing season, support coniferous forest rather than sagebrush steppe ecosystems, stabilize slopes at steeper angles, and produce sparser drainage networks. We hypothesize that the primary drivers of valley asymmetry development are changes in the pedon-scale water-balance that coalesce to alter catchment-scale runoff and drainage development, and ultimately cause the divide between north and south-facing land surfaces to migrate northward. We explore this conceptual framework by coupling land surface analyses with statistical modeling to assess relationships and the relative importance of land surface characteristics. Throughout the Idaho batholith, we systematically mapped and tabulated various statistical measures of landforms, land cover, and hydroclimate within discrete valley segments (n=~10,000). We developed a random forest based statistical model to predict valley slope asymmetry based upon numerous measures (n>300) of landscape asymmetries. Preliminary results suggest that drainages are tightly coupled with hillslopes throughout the region, with drainage-network slope being one of the strongest predictors of land-surface-averaged slope asymmetry. When slope-related statistics are excluded, due to possible autocorrelation, valley slope asymmetry is most strongly predicted by asymmetries of insolation and drainage density, which generally supports a water-balance based conceptual model of valley asymmetry development. Surprisingly, vegetation asymmetries had relatively low predictive importance.
Orphan therapies: making best use of postmarket data.
Maro, Judith C; Brown, Jeffrey S; Dal Pan, Gerald J; Li, Lingling
2014-08-01
Postmarket surveillance of the comparative safety and efficacy of orphan therapeutics is challenging, particularly when multiple therapeutics are licensed for the same orphan indication. To make best use of product-specific registry data collected to fulfill regulatory requirements, we propose the creation of a distributed electronic health data network among registries. Such a network could support sequential statistical analyses designed to detect early warnings of excess risks. We use a simulated example to explore the circumstances under which a distributed network may prove advantageous. We perform sample size calculations for sequential and non-sequential statistical studies aimed at comparing the incidence of hepatotoxicity following initiation of two newly licensed therapies for homozygous familial hypercholesterolemia. We calculate the sample size savings ratio, or the proportion of sample size saved if one conducted a sequential study as compared to a non-sequential study. Then, using models to describe the adoption and utilization of these therapies, we simulate when these sample sizes are attainable in calendar years. We then calculate the analytic calendar time savings ratio, analogous to the sample size savings ratio. We repeat these analyses for numerous scenarios. Sequential analyses detect effect sizes earlier or at the same time as non-sequential analyses. The most substantial potential savings occur when the market share is more imbalanced (i.e., 90% for therapy A) and the effect size is closest to the null hypothesis. However, due to low exposure prevalence, these savings are difficult to realize within the 30-year time frame of this simulation for scenarios in which the outcome of interest occurs at or more frequently than one event/100 person-years. We illustrate a process to assess whether sequential statistical analyses of registry data performed via distributed networks may prove a worthwhile infrastructure investment for pharmacovigilance.
Analysis of First-Time Unsuccessful Attempts on the Certified Nurse Educator Examination.
Lundeen, John D
This retrospective analysis examined first-time unsuccessful attempts on the Certified Nurse Educator (CNE) examination from September 2005 through September 2011 (n = 390). There are few studies examining certification within the academic nurse educator role. There is also a lack of evidence to assist nurse educators in understanding those factors that best support success on the CNE exam. Nonexperimental, descriptive, retrospective correlational design using chi-square test of independence and factorial analyses of variance. A statistically significant relationship was found between first-time failure and highest degree obtained and institutional affiliation on the CNE exam. There was no statistically significant effect on mean scores in any of the six content areas measured by the CNE exam as related to highest degree or institutional affiliation. The findings from this study support a previous recommendation for faculty development, experience in the role, and doctoral preparation prior to seeking certification.
Family support in cancer survivorship.
Muhamad, Mazanah; Afshari, Mojgan; Kazilan, Fitrisehara
2011-01-01
This paper raises issues about the role of family members in providing support for breast cancer survivors. Data were collected from 400 breast cancer survivors in Peninsular Malaysia through a custom-designed questionnaire fielded at hospitals and support group meetings. The data were analyzed using descriptive statistics. The analyses show that all family members could be supportive, especially in decision making and help with emotional issues. The spouse was the main support provider among the family members (others were children, parents, siblings and more distant relatives). The results also indicated that a significant percentage practiced collaborative decision-making. Breast cancer survivors needed their family members' support for information on survivorship strategies such as managing emotions, health, life style and dietary practice. The family members' supportive role may be linked to the Malaysian strong family relationship culture. For family members to contribute more adequately to cancer survivorship, it is suggested that appropriate educational intervention also be provided to them.
Stewart, Gavin B.; Altman, Douglas G.; Askie, Lisa M.; Duley, Lelia; Simmonds, Mark C.; Stewart, Lesley A.
2012-01-01
Background Individual participant data (IPD) meta-analyses that obtain “raw” data from studies rather than summary data typically adopt a “two-stage” approach to analysis whereby IPD within trials generate summary measures, which are combined using standard meta-analytical methods. Recently, a range of “one-stage” approaches which combine all individual participant data in a single meta-analysis have been suggested as providing a more powerful and flexible approach. However, they are more complex to implement and require statistical support. This study uses a dataset to compare “two-stage” and “one-stage” models of varying complexity, to ascertain whether results obtained from the approaches differ in a clinically meaningful way. Methods and Findings We included data from 24 randomised controlled trials, evaluating antiplatelet agents, for the prevention of pre-eclampsia in pregnancy. We performed two-stage and one-stage IPD meta-analyses to estimate overall treatment effect and to explore potential treatment interactions whereby particular types of women and their babies might benefit differentially from receiving antiplatelets. Two-stage and one-stage approaches gave similar results, showing a benefit of using anti-platelets (Relative risk 0.90, 95% CI 0.84 to 0.97). Neither approach suggested that any particular type of women benefited more or less from antiplatelets. There were no material differences in results between different types of one-stage model. Conclusions For these data, two-stage and one-stage approaches to analysis produce similar results. Although one-stage models offer a flexible environment for exploring model structure and are useful where across study patterns relating to types of participant, intervention and outcome mask similar relationships within trials, the additional insights provided by their usage may not outweigh the costs of statistical support for routine application in syntheses of randomised controlled trials. Researchers considering undertaking an IPD meta-analysis should not necessarily be deterred by a perceived need for sophisticated statistical methods when combining information from large randomised trials. PMID:23056232
Statistics for NAEG: past efforts, new results, and future plans
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gilbert, R.O.; Simpson, J.C.; Kinnison, R.R.
A brief review of Nevada Applied Ecology Group (NAEG) objectives is followed by a summary of past statistical analyses conducted by Pacific Northwest Laboratory for the NAEG. Estimates of spatial pattern of radionuclides and other statistical analyses at NS's 201, 219 and 221 are reviewed as background for new analyses presented in this paper. Suggested NAEG activities and statistical analyses needed for the projected termination date of NAEG studies in March 1986 are given.
Chevance, Aurélie; Schuster, Tibor; Steele, Russell; Ternès, Nils; Platt, Robert W
2015-10-01
Robustness of an existing meta-analysis can justify decisions on whether to conduct an additional study addressing the same research question. We illustrate the graphical assessment of the potential impact of an additional study on an existing meta-analysis using published data on statin use and the risk of acute kidney injury. A previously proposed graphical augmentation approach is used to assess the sensitivity of the current test and heterogeneity statistics extracted from existing meta-analysis data. In addition, we extended the graphical augmentation approach to assess potential changes in the pooled effect estimate after updating a current meta-analysis and applied the three graphical contour definitions to data from meta-analyses on statin use and acute kidney injury risk. In the considered example data, the pooled effect estimates and heterogeneity indices demonstrated to be considerably robust to the addition of a future study. Supportingly, for some previously inconclusive meta-analyses, a study update might yield statistically significant kidney injury risk increase associated with higher statin exposure. The illustrated contour approach should become a standard tool for the assessment of the robustness of meta-analyses. It can guide decisions on whether to conduct additional studies addressing a relevant research question. Copyright © 2015 Elsevier Inc. All rights reserved.
PULPAL BLOOD FLOW CHANGES IN ABUTMENT TEETH OF REMOVABLE PARTIAL DENTURES
Kunt, Göknil Ergün; Kökçü, Deniz; Ceylan, Gözlem; Yılmaz, Nergiz; Güler, Ahmet Umut
2009-01-01
The purpose of this study was to investigate the effect of tooth supported (TSD) and toothtissue supported (TTSD) removable partial denture wearing on pulpal blood flow (PBF) of the abutment teeth by using Laser Doppler Flowmeter (LDF). Measurements were carried out on 60 teeth of 28 patients (28 teeth and 12 patients of TTSD group, 32 teeth and 16 patients of TSD group) who had not worn any type of removable partial dentures before, had no systemic problems and were non smokers. PBF values were recorded by LDF before insertion (day 0) and after insertion of dentures at day 1, day 7 and day 30. Statistical analysis was performed by student t test and covariance analyses of repeated measurements. In the group TTSD, the mean values of PBF decreased statistically significantly at day 1 after insertion when compared with PBF values before insertion (p<0,01). There was no statistically significant difference among PBF mean values on 1st, 7th and 30th day. However, in the group TSD, there was no statistically significant difference among PBF mean values before insertion and on 1st, 7th and 30th day. In other words, PBF mean values in group TSD continued without changing statistically significant on 1st, 7th and 30th day. TTSD wearing may show negative effect on the abutment teeth due to decreasing basal PBF. PMID:20001995
Lundervold, Astri J.; Breivik, Kyrre; Posserud, Maj-Britt; Stormark, Kjell Morten; Hysing, Mari
2013-01-01
The present study investigated sex-differences in reports of depressive symptoms on a Norwegian translation of the short version of the Mood and Feelings Questionnaire (SMFQ). The sample comprised 9702 Norwegian adolescents (born 1993–1995, 54.9% girls), mainly attending highschool. A set of statistical analyses were run to investigate the dimensionality of the SMFQ. Girls scored significantly higher than boys on the SMFQ and used the most severe response-category far more frequently. Overall, the statistical analyses supported the essential unidimensionality of SMFQ. However, the items with the highest loadings according to the bifactor analysis, reflecting problems related to tiredness, restlessness and concentration difficulties, indicated that some of the symptoms may both be independent of and part of the symptomatology of depression. Measurement invariance analysis showed that girls scored slightly higher on some items when taking the latent variable into account; girls had a lower threshold for reporting mood problems and problems related to tiredness than boys, who showed a marginally lower threshold for reporting that no-one loved them. However, the effect on the total SMFQ score was marginal, supporting the use of the Norwegian translation of SMFQ as a continuous variable in further studies of adolescents. PMID:24062708
Finke, Erinn H; Hickerson, Benjamin; McLaughlin, Eileen
2015-04-01
The purpose of this study was to determine parental attitudes regarding engagement with video games by their children with autism spectrum disorder (ASD) and whether attitudes vary based on ASD symptom severity. Online survey methodology was used to gather information from parents of children with ASD between the ages of 8 and 12 years. The finalized data set included 152 cases. Descriptive statistics and frequency analyses were used to examine participant demographics and video game play. Descriptive and inferential statistics were used to evaluate questions on the theory of planned behavior. Regression analyses determined the predictive ability of the theory of planned behavior constructs, and t tests provided additional descriptive information about between-group differences. Children with ASD play video games. There are no significant differences in the time, intensity, or types of games played based on severity of ASD symptoms (mild vs. moderate). Parents of children with ASD had positive attitudes about video game play. Parents of children with ASD appear to support video game play. On average, parents indicated video game play was positive for their children with ASD, particularly if they believed the games were having a positive impact on their child's development.
Horita, Yuji; Otsuka, Yasumasa
2014-01-01
In the NIOSH Generic Job Stress Model, social support is assumed to moderate the relationship between job stressors and stress responses. However, few studies have investigated how to enhance social support in the workplace. The purpose of this study was to explore the relationships between interpersonal helping behavior, social support, job stressors, psychological stress responses, and vigor among Japanese workers. A total of 240 workers in manufacturing companies returned a questionnaire regarding their interpersonal helping behavior, social support, job stressors, psychological stress responses, and vigor (response rate = 96.0%). After excluding 40 participants due to missing responses, data from a total of 200 participants (163 male and 37 female, mean age = 40.3 yr) were used in the final analyses. Interpersonal helping behavior was assessed by the Japanese version of the Organizational Citizenship Behavior Scale. The Brief Job Stress Questionnaire was used to measure job stressors, psychological stress responses, social support, and vigor. Structured equation modeling was performed to examine the relationships between interpersonal helping behavior, social support, job stressors, psychological stress responses, and vigor. Interpersonal helping behavior had a statistically significant negative effect on psychological stress response through increasing social support. However, interpersonal helping behavior had a statistically significant positive effect on psychological stress response through increasing the quantitative workload. Of these two effects, the former was stronger than the latter. In addition, interpersonal helping behavior had a statistically significant positive effect on vigor through increasing social support. Although interpersonal helping behavior, which helps other workers may increase quantitative workload, leading to high levels of psychological stress responses, that same behavior strengthens trust and team spirit among workers and may enhance social support, leading to low levels of psychological stress responses and high levels of vigor. However, reverse causal relationships may also exist, because our study design was cross-sectional.
Poikkeus, Tarja; Leino-Kilpi, Helena; Katajisto, Jouko
2014-09-01
The aim of this study was to analyse how nurse leaders support the ethical competence of nurses during recruitment and performance reviews. Ethical competence of nurses refers to ethical behaviour and action requiring ethical knowledge and reflection. Nurse leaders have a key role in supporting the ethical competence of nurses, but little is known about just how this should be done. The data were collected using a structured questionnaire and analysed statistically. The target sample consisted of nurse leaders (n = 198) from two university hospitals in two healthcare districts in Finland. Nurse leaders support the ethical competence of nurses more often during performance reviews than during recruitment. During recruitment, nurse leaders ensure the ethical behaviour and knowledge of nurses to varying degrees. During performance reviews, nurse leaders ensure that nurses meet the requirements for collegiality and comply with ethical guidelines and that they do so according to nursing values and principles. There seems to be a need to examine and improve support for the ethical competence of nurses, both during recruitment and performance reviews. Future priorities should include a focus on supporting the ethical knowledge, reflection and behaviour of nurses. An important aspect in terms of supporting the ethical competence of nurses has to do with the ethical knowledge and education of nurse leaders and organisational policies or recommendations for ethical support. © 2013 John Wiley & Sons Ltd.
Wolf, Erika J.; Mitchell, Karen S.; Sadeh, Naomi; Hein, Christina; Fuhrman, Isaac; Pietrzak, Robert H.; Miller, Mark W.
2015-01-01
The fifth edition of the Diagnostic and Statistical Manual (DSM-5) includes a dissociative subtype of posttraumatic stress disorder (PTSD), but no existing measures specifically assess it. This paper describes the initial evaluation of a 15-item self-report measure of the subtype called the Dissociative Subtype of PTSD Scale (DSPS) in an on-line survey of 697 trauma-exposed military veterans representative of the US veteran population. Exploratory factor analyses of the lifetime DSPS items supported the intended structure of the measure consisting of three factors reflecting derealization/depersonalization, loss of awareness, and psychogenic amnesia. Consistent with prior research, latent profile analyses assigned 8.3% of the sample to a highly dissociative class distinguished by pronounced symptoms of derealization and depersonalization. Overall, results provide initial psychometric support for the lifetime DSPS scales; additional research in clinical and community samples is needed to further validate the measure. PMID:26603115
Wolf, Erika J; Mitchell, Karen S; Sadeh, Naomi; Hein, Christina; Fuhrman, Isaac; Pietrzak, Robert H; Miller, Mark W
2017-06-01
The fifth edition of the Diagnostic and Statistical Manual includes a dissociative subtype of posttraumatic stress disorder, but no existing measures specifically assess it. This article describes the initial evaluation of a 15-item self-report measure of the subtype called the Dissociative Subtype of Posttraumatic Stress Disorder Scale (DSPS) in an online survey of 697 trauma-exposed military veterans representative of the U.S. veteran population. Exploratory factor analyses of the lifetime DSPS items supported the intended structure of the measure consisting of three factors reflecting derealization/depersonalization, loss of awareness, and psychogenic amnesia. Consistent with prior research, latent profile analyses assigned 8.3% of the sample to a highly dissociative class distinguished by pronounced symptoms of derealization and depersonalization. Overall, results provide initial psychometric support for the lifetime DSPS scales; additional research in clinical and community samples is needed to further validate the measure.
Socioscientific Argumentation: The effects of content knowledge and morality
NASA Astrophysics Data System (ADS)
Sadler, Troy D.; Donnelly, Lisa A.
2006-10-01
Broad support exists within the science education community for the incorporation of socioscientific issues (SSI) and argumentation in the science curriculum. This study investigates how content knowledge and morality contribute to the quality of SSI argumentation among high school students. We employed a mixed-methods approach: 56 participants completed tests of content knowledge and moral reasoning as well as interviews, related to SSI topics, which were scored based on a rubric for argumentation quality. Multiple regression analyses revealed no statistically significant relationships among content knowledge, moral reasoning, and argumentation quality. Qualitative analyses of the interview transcripts supported the quantitative results in that participants very infrequently revealed patterns of content knowledge application. However, most of the participants did perceive the SSI as moral problems. We propose a “Threshold Model of Knowledge Transfer” to account for the relationship between content knowledge and argumentation quality. Implications for science education are discussed.
Towards interoperable and reproducible QSAR analyses: Exchange of datasets.
Spjuth, Ola; Willighagen, Egon L; Guha, Rajarshi; Eklund, Martin; Wikberg, Jarl Es
2010-06-30
QSAR is a widely used method to relate chemical structures to responses or properties based on experimental observations. Much effort has been made to evaluate and validate the statistical modeling in QSAR, but these analyses treat the dataset as fixed. An overlooked but highly important issue is the validation of the setup of the dataset, which comprises addition of chemical structures as well as selection of descriptors and software implementations prior to calculations. This process is hampered by the lack of standards and exchange formats in the field, making it virtually impossible to reproduce and validate analyses and drastically constrain collaborations and re-use of data. We present a step towards standardizing QSAR analyses by defining interoperable and reproducible QSAR datasets, consisting of an open XML format (QSAR-ML) which builds on an open and extensible descriptor ontology. The ontology provides an extensible way of uniquely defining descriptors for use in QSAR experiments, and the exchange format supports multiple versioned implementations of these descriptors. Hence, a dataset described by QSAR-ML makes its setup completely reproducible. We also provide a reference implementation as a set of plugins for Bioclipse which simplifies setup of QSAR datasets, and allows for exporting in QSAR-ML as well as old-fashioned CSV formats. The implementation facilitates addition of new descriptor implementations from locally installed software and remote Web services; the latter is demonstrated with REST and XMPP Web services. Standardized QSAR datasets open up new ways to store, query, and exchange data for subsequent analyses. QSAR-ML supports completely reproducible creation of datasets, solving the problems of defining which software components were used and their versions, and the descriptor ontology eliminates confusions regarding descriptors by defining them crisply. This makes is easy to join, extend, combine datasets and hence work collectively, but also allows for analyzing the effect descriptors have on the statistical model's performance. The presented Bioclipse plugins equip scientists with graphical tools that make QSAR-ML easily accessible for the community.
Towards interoperable and reproducible QSAR analyses: Exchange of datasets
2010-01-01
Background QSAR is a widely used method to relate chemical structures to responses or properties based on experimental observations. Much effort has been made to evaluate and validate the statistical modeling in QSAR, but these analyses treat the dataset as fixed. An overlooked but highly important issue is the validation of the setup of the dataset, which comprises addition of chemical structures as well as selection of descriptors and software implementations prior to calculations. This process is hampered by the lack of standards and exchange formats in the field, making it virtually impossible to reproduce and validate analyses and drastically constrain collaborations and re-use of data. Results We present a step towards standardizing QSAR analyses by defining interoperable and reproducible QSAR datasets, consisting of an open XML format (QSAR-ML) which builds on an open and extensible descriptor ontology. The ontology provides an extensible way of uniquely defining descriptors for use in QSAR experiments, and the exchange format supports multiple versioned implementations of these descriptors. Hence, a dataset described by QSAR-ML makes its setup completely reproducible. We also provide a reference implementation as a set of plugins for Bioclipse which simplifies setup of QSAR datasets, and allows for exporting in QSAR-ML as well as old-fashioned CSV formats. The implementation facilitates addition of new descriptor implementations from locally installed software and remote Web services; the latter is demonstrated with REST and XMPP Web services. Conclusions Standardized QSAR datasets open up new ways to store, query, and exchange data for subsequent analyses. QSAR-ML supports completely reproducible creation of datasets, solving the problems of defining which software components were used and their versions, and the descriptor ontology eliminates confusions regarding descriptors by defining them crisply. This makes is easy to join, extend, combine datasets and hence work collectively, but also allows for analyzing the effect descriptors have on the statistical model's performance. The presented Bioclipse plugins equip scientists with graphical tools that make QSAR-ML easily accessible for the community. PMID:20591161
Fernquist, Robert M
2007-01-01
Sociological research on Durkheim's theories of egoistic and anomic suicide has given Durkheim continued support more than a century after Durkheim published his work. Recent criticism by Breault (1994), though, argues that Durkheim's theories of suicide actually have not been empirically supported given the lack of psychological variables included in sociological research on suicide rates. Using proxy measures of depression and alcoholism, two known psychological variables to impact suicide, as well as classic Durkheimian variables, suicide rates in eight European countries from 1973-1997 were examined. Results indicate that Durkheim's theories of egoism and anomie, while not completely supported in statistical analysis of suicide rates, received moderate support. Results suggest the continued usefulness of Durkheim's work in aggregate analyses of suicide.
Sanne, Bjarte; Mykletun, Arnstein; Dahl, Alv A; Moen, Bente E; Tell, Grethe S
2005-09-01
To test the strain/iso-strain, interaction and buffer hypotheses of the Job Demand-Control-Support model in relation to anxiety and depression. Five thousand five hundred and sixty-two workers with valid Demand-Control-Support Questionnaire (DCSQ) scores were examined with the sub-scales of the Hospital Anxiety and Depression Scale as outcomes. Multiple statistical methods were applied. The strain and iso-strain hypotheses were confirmed. Generally, additive and non-interaction effects were found between psychological demands, control and social support. The buffer hypotheses were refuted. Results from analyses testing different interaction operationalizations were complementary. High demands, low control and low support individually, but particularly combined, are risk factors for anxiety and depression. Support is the DCSQ index most strongly associated with anxiety and depression in women. Assessment of psychosocial work environment may identify workers at risk, and serve as a basis for job-redesign.
An experimental analysis of the real contact area between an electrical contact and a glass plane
NASA Astrophysics Data System (ADS)
Down, Michael; Jiang, Liudi; McBride, John W.
2013-06-01
The exact contact between two rough surfaces is usually estimated using statistical mathematics and surface analysis before and after contact has occurred. To date the majority of real contact and loaded surfaces has been theoretical or by numerical analyses. A method of analysing real contact area under various loads, by utilizing a con-contact laser surface profiler, allows direct measurement of contact area and deformation in terms of contact force and plane displacement between two surfaces. A laser performs a scan through a transparent flat side supported in a fixed position above the base. A test contact, mounted atop a spring and force sensor, and a screw support which moves into contact with the transparent surface. This paper presents the analysis of real contact area of various surfaces under various loads. The surfaces analysed are a pair of Au coated hemispherical contacts, one is a used Au to Au coated multi-walled carbon nanotubes surface, from a MEMS relay application, the other a new contact surface of the same configuration.
Mindful attention and awareness: relationships with psychopathology and emotion regulation.
Gregório, Sónia; Pinto-Gouveia, José
2013-01-01
The growing interest in mindfulness from the scientific community has originated several self-report measures of this psychological construct. The Mindful Attention and Awareness Scale (MAAS) is a self-report measure of mindfulness at a trait-level. This paper aims at exploring MAAS psychometric characteristics and validating it for the Portuguese population. The first two studies replicate some of the original author's statistical procedures in two different samples from the Portuguese general community population, in particular confirmatory factor analyses. Results from both analyses confirmed the scale single-factor structure and indicated a very good reliability. Moreover, cross-validation statistics showed that this single-factor structure is valid for different respondents from the general community population. In the third study the Portuguese version of the MAAS was found to have good convergent and discriminant validities. Overall the findings support the psychometric validity of the Portuguese version of MAAS and suggest this is a reliable self-report measure of trait-mindfulness, a central construct in Clinical Psychology research and intervention fields.
McConkey, Roy; Bunting, Brendan; Keogh, Fiona; Garcia Iriarte, Edurne
2017-01-01
A natural experiment contrasted the social relationships of people with intellectual disabilities ( n = 110) before and after they moved from congregated settings to either personalized accommodation or group homes. Contrasts could also be drawn with individuals who had enduring mental health problems ( n = 46) and who experienced similar moves. Face-to-face interviews were conducted in each person's residence on two occasions approximately 24 months apart. Multivariate statistical analyses were used to determine significant effects. Greater proportions of people living in personalized settings scored higher on the five chosen indicators of social relationships than did persons living in grouped accommodation. However, multivariate statistical analyses identified that only one in five persons increased their social relationships as a result of changes in their accommodation, particularly persons with an intellectual disability and high support needs. These findings reinforce the extent of social isolation experienced by people with disabilities and mental health problems that changes in their accommodation only partially counter.
Parasites as valuable stock markers for fisheries in Australasia, East Asia and the Pacific Islands.
Lester, R J G; Moore, B R
2015-01-01
Over 30 studies in Australasia, East Asia and the Pacific Islands region have collected and analysed parasite data to determine the ranges of individual fish, many leading to conclusions about stock delineation. Parasites used as biological tags have included both those known to have long residence times in the fish and those thought to be relatively transient. In many cases the parasitological conclusions have been supported by other methods especially analysis of the chemical constituents of otoliths, and to a lesser extent, genetic data. In analysing parasite data, authors have applied multiple different statistical methodologies, including summary statistics, and univariate and multivariate approaches. Recently, a growing number of researchers have found non-parametric methods, such as analysis of similarities and cluster analysis, to be valuable. Future studies into the residence times, life cycles and geographical distributions of parasites together with more robust analytical methods will yield much important information to clarify stock structures in the area.
Samanta, Brajogopal; Bhadury, Punyasloke
2016-01-01
Marine chromophytes are taxonomically diverse group of algae and contribute approximately half of the total oceanic primary production. To understand the global patterns of functional diversity of chromophytic phytoplankton, robust bioinformatics and statistical analyses including deep phylogeny based on 2476 form ID rbcL gene sequences representing seven ecologically significant oceanographic ecoregions were undertaken. In addition, 12 form ID rbcL clone libraries were generated and analyzed (148 sequences) from Sundarbans Biosphere Reserve representing the world’s largest mangrove ecosystem as part of this study. Global phylogenetic analyses recovered 11 major clades of chromophytic phytoplankton in varying proportions with several novel rbcL sequences in each of the seven targeted ecoregions. Majority of OTUs was found to be exclusive to each ecoregion, whereas some were shared by two or more ecoregions based on beta-diversity analysis. Present phylogenetic and bioinformatics analyses provide a strong statistical support for the hypothesis that different oceanographic regimes harbor distinct and coherent groups of chromophytic phytoplankton. It has been also shown as part of this study that varying natural selection pressure on form ID rbcL gene under different environmental conditions could lead to functional differences and overall fitness of chromophytic phytoplankton populations. PMID:26861415
Leeseberg Stamler, L; Cole, M M; Patrick, L J
2001-08-01
Strategies to delay or prevent complications from diabetes include diabetes patient education. Diabetes educators seek to provide education that meets the needs of clients and influences positive health outcomes. (1) To expand prior research exploring an enablement framework for patient education by examining perceptions of patient education by persons with diabetes and (2) to test the mastery of stress instrument (MSI) as a potential evaluative instrument for patient education. Triangulated data collection with a convenience sample of adults taking diabetes education classes. Half the sample completed audio-taped semi-structured interviews pre, during and posteducation and all completed the MSI posteducation. Qualitative data were analysed using latent content analysis, descriptive statistics were completed. Qualitative analysis revealed content categories similar to previous work with prenatal participants, supporting the enablement framework. Statistical analyses noted congruence with psychometric findings from development of MSI; secondary qualitative analyses revealed congruency between MSI scores and patient perceptions. Mastery is an outcome congruent with the enablement framework for patient education across content areas. Mastery of stress instrument may be a instrument for identification of patients who are coping well with diabetes self-management, as well as those who are not and who require further nursing interventions.
Vleeshouwers, Jolien; Knardahl, Stein; Christensen, Jan Olav
2016-04-01
This prospective cohort study examined previously underexplored relations between psychological/social work factors and troubled sleep in order to provide practical information about specific, modifiable factors at work. A comprehensive evaluation of a range of psychological/social work factors was obtained by several designs; i.e., cross-sectional analyses at baseline and follow-up, prospective analyses with baseline predictors (T1), prospective analyses with average exposure across waves as predictor ([T1 + T2] / 2), and prospective analyses with change in exposure from baseline to follow-up as predictor. Participants consisted of a sample of Norwegian employees from a broad spectrum of occupations, who completed a questionnaire at two points in time, approximately two years apart. Cross-sectional analyses at T1 comprised 7,459 participants, cross-sectional analyses at T2 included 6,688 participants. Prospective analyses comprised a sample 5,070 of participants who responded at both T1 and T2. Univariable and multivariable ordinal logistic regressions were performed. Thirteen psychological/social work factors and two aspects of troubled sleep, namely difficulties initiating sleep and disturbed sleep, were studied. Ordinal logistic regressions revealed statistically significant associations for all psychological and social work factors in at least one of the analyses. Psychological and social work factors predicted sleep problems in the short term as well as the long term. All work factors investigated showed statistically significant associations with both sleep items, however quantitative job demands, decision control, role conflict, and support from superior were the most robust predictors and may therefore be suitable targets of interventions aimed at improving employee sleep. © 2016 Associated Professional Sleep Societies, LLC.
Quantifying the Relationship between AMC Resources and U.S. Army Materiel Readiness
1989-08-25
Resource Management report 984 for the same period. Insufficient data precluded analysis of the OMA PEs Total Package Fielding and Life Cycle Software...procurement, had the greatest failure rates when subjected to the statistical tests merely because of the reduced number of data pairs. Analyses of...ENGINEERING DEVELOPMENT 6.5 - MANAGEMENT AND SUPPORT 6.7 - OPERATIONAL SYSTEM DEVELOPMENT P2 - GENERAL PURPOSE FORCES P3 - INTELIGENCE AND COMMUNICATIONS P7
Glozah, Franklin N; Pevalin, David J
2015-08-01
To examine the role of perceived social support and parental education on physical activity and eating behaviour of Ghanaian adolescents. Seven hundred and seventy Senior High School students (504 boys and 266 girls) between the ages of 14-21 years participated by completing questionnaires on perceived social support, physical activity and eating behaviour. The highest education attained by either parent or guardian was also obtained. Multivariate analysis of covariance was the main statistical test used to analyse the data. The results showed significant gender differences in physical activity and eating behaviour combined, with boys more likely to engage in physical activity than girls, and girls also more likely to engage in healthy eating behaviour than boys, albeit the effect was not statistically significant. While perceived social support had a significant positive effect on eating behaviour and physical activity, parental education had a significant effect only on eating behaviour but not physical activity. Perceived social support from family coupled with parental education provides more opportunities for adolescents to engage in healthy eating behaviour. Also, parents' educational attainment alone does not necessarily guarantee that adolescents will engage in physical activity; providing the needed social support and conducive home environment is more likely to induce physical activity behaviours. Finally, physical activity and eating behaviour should not be construed as alternative health behaviours as suggested by gender differentials in these health behaviours.
NASA Astrophysics Data System (ADS)
Agus, M.; Penna, M. P.; Peró-Cebollero, M.; Guàrdia-Olmos, J.
2015-02-01
Numerous studies have examined students' difficulties in understanding some notions related to statistical problems. Some authors observed that the presentation of distinct visual representations could increase statistical reasoning, supporting the principle of graphical facilitation. But other researchers disagree with this viewpoint, emphasising the impediments related to the use of illustrations that could overcharge the cognitive system with insignificant data. In this work we aim at comparing the probabilistic statistical reasoning regarding two different formats of problem presentations: graphical and verbal-numerical. We have conceived and presented five pairs of homologous simple problems in the verbal numerical and graphical format to 311 undergraduate Psychology students (n=156 in Italy and n=155 in Spain) without statistical expertise. The purpose of our work was to evaluate the effect of graphical facilitation in probabilistic statistical reasoning. Every undergraduate has solved each pair of problems in two formats in different problem presentation orders and sequences. Data analyses have highlighted that the effect of graphical facilitation is infrequent in psychology undergraduates. This effect is related to many factors (as knowledge, abilities, attitudes, and anxiety); moreover it might be considered the resultant of interaction between individual and task characteristics.
Is everything we eat associated with cancer? A systematic cookbook review.
Schoenfeld, Jonathan D; Ioannidis, John P A
2013-01-01
Nutritional epidemiology is a highly prolific field. Debates on associations of nutrients with disease risk are common in the literature and attract attention in public media. We aimed to examine the conclusions, statistical significance, and reproducibility in the literature on associations between specific foods and cancer risk. We selected 50 common ingredients from random recipes in a cookbook. PubMed queries identified recent studies that evaluated the relation of each ingredient to cancer risk. Information regarding author conclusions and relevant effect estimates were extracted. When >10 articles were found, we focused on the 10 most recent articles. Forty ingredients (80%) had articles reporting on their cancer risk. Of 264 single-study assessments, 191 (72%) concluded that the tested food was associated with an increased (n = 103) or a decreased (n = 88) risk; 75% of the risk estimates had weak (0.05 > P ≥ 0.001) or no statistical (P > 0.05) significance. Statistically significant results were more likely than nonsignificant findings to be published in the study abstract than in only the full text (P < 0.0001). Meta-analyses (n = 36) presented more conservative results; only 13 (26%) reported an increased (n = 4) or a decreased (n = 9) risk (6 had more than weak statistical support). The median RRs (IQRs) for studies that concluded an increased or a decreased risk were 2.20 (1.60, 3.44) and 0.52 (0.39, 0.66), respectively. The RRs from the meta-analyses were on average null (median: 0.96; IQR: 0.85, 1.10). Associations with cancer risk or benefits have been claimed for most food ingredients. Many single studies highlight implausibly large effects, even though evidence is weak. Effect sizes shrink in meta-analyses.
Tamou, Charles; Ripoll-Bosch, Raimon; de Boer, Imke J M; Oosting, Simon J
2018-04-01
Pastoralists face increasing competition for land with crop farmers and nature in and around the W Biosphere Reserve (WBR) in Benin. Our aim was to describe and analyse land use changes in order to understand their drivers, and to describe and analyse the viewpoints of relevant stakeholders in order to understand the competition for land. To this end, remote sensing data, regional statistics, and survey data were collected. We found that crop land expansion around the WBR was the direct driver of decrease of the grazing land area. Population growth and rising demand for food crops, and government support to the cotton sector were indirect drivers of grazing land reduction. Furthermore, competing claims on land among users arose from the complex interaction of crop expansion, presence of WBR and the way it is governed, the lack of support to pastoralists, and the increasing shift of pastoralists' lifestyle into one of settled crop farmers. Pastoralism is under threat and its survival depends on the successful implementation of policies to support pastoralists and protect grazing lands.
Meta-Analysis of Inquiry-Based Instruction Research
NASA Astrophysics Data System (ADS)
Hasanah, N.; Prasetyo, A. P. B.; Rudyatmi, E.
2017-04-01
Inquiry-based instruction in biology has been the focus of educational research conducted by Unnes biology department students in collaboration with their university supervisors. This study aimed to describe the methodological aspects, inquiry teaching methods critically, and to analyse the results claims, of the selected four student research reports, grounded in inquiry, based on the database of Unnes biology department 2014. Four experimental quantitative research of 16 were selected as research objects by purposive sampling technique. Data collected through documentation study was qualitatively analysed regarding methods used, quality of inquiry syntax, and finding claims. Findings showed that the student research was still the lack of relevant aspects of research methodology, namely in appropriate sampling procedures, limited validity tests of all research instruments, and the limited parametric statistic (t-test) not supported previously by data normality tests. Their consistent inquiry syntax supported the four mini-thesis claims that inquiry-based teaching influenced their dependent variables significantly. In other words, the findings indicated that positive claims of the research results were not fully supported by good research methods, and well-defined inquiry procedures implementation.
Tsai, Jack; Rosenheck, Robert A
2015-06-01
There has long been concern that public support payments are used to support addictive behaviors. This study examined the amount of money homeless veterans spend on alcohol and drugs and the association between public support income, including VA disability compensation, and expenditures on alcohol and drugs. Data were from 1,160 veterans from 19 sites on entry into the Housing and Urban Development-Veterans Affairs Supportive Housing program. Descriptive statistics and nonparametric analyses were conducted. About 33% of veterans reported spending money on alcohol and 22% reported spending money on drugs in the past month. No significant association was found between public support income, VA disability compensation, and money spent on alcohol and drugs. A substantial proportion of homeless veterans spend some income on alcohol and drugs, but disability income, including VA compensation, does not seem to be related to substance use or money spent on addictive substances.
Martian cratering 11. Utilizing decameter scale crater populations to study Martian history
NASA Astrophysics Data System (ADS)
Hartmann, W. K.; Daubar, I. J.
2017-03-01
New information has been obtained in recent years regarding formation rates and the production size-frequency distribution (PSFD) of decameter-scale primary Martian craters formed during recent orbiter missions. Here we compare the PSFD of the currently forming small primaries (P) with new data on the PSFD of the total small crater population that includes primaries and field secondaries (P + fS), which represents an average over longer time periods. The two data sets, if used in a combined manner, have extraordinary potential for clarifying not only the evolutionary history and resurfacing episodes of small Martian geological formations (as small as one or few km2) but also possible episodes of recent climatic change. In response to recent discussions of statistical methodologies, we point out that crater counts do not produce idealized statistics, and that inherent uncertainties limit improvements that can be made by more sophisticated statistical analyses. We propose three mutually supportive procedures for interpreting crater counts of small craters in this context. Applications of these procedures support suggestions that topographic features in upper meters of mid-latitude ice-rich areas date only from the last few periods of extreme Martian obliquity, and associated predicted climate excursions.
NASA Astrophysics Data System (ADS)
Funk, C. C.; Shukla, S.; Hoerling, M. P.; Robertson, F. R.; Hoell, A.; Liebmann, B.
2013-12-01
During boreal spring, eastern portions of Kenya and Somalia have experienced more frequent droughts since 1999. Given the region's high levels of food insecurity, better predictions of these droughts could provide substantial humanitarian benefits. We show that dynamical-statistical seasonal climate forecasts, based on the latest generation of coupled atmosphere-ocean and uncoupled atmospheric models, effectively predict boreal spring rainfall in this area. Skill sources are assessed by comparing ensembles driven with full-ocean forcing with ensembles driven with ENSO-only sea surface temperatures (SSTs). Our analysis suggests that both ENSO and non-ENSO Indo-Pacific SST forcing have played an important role in the increase in drought frequencies. Over the past 30 years, La Niña drought teleconnections have strengthened, while non-ENSO Indo-Pacific convection patterns have also supported increased (decreased) Western Pacific (East African) rainfall. To further examine the relative contribution of ENSO, low frequency warming and the Pacific Decadal Oscillation, we present decompositions of ECHAM5, GFS, CAM4 and GMAO AMIP simulations. These decompositions suggest that rapid warming in the western Pacific and steeper western-to-central Pacific SST gradients have likely played an important role in the recent intensification of the Walker circulation, and the associated increase in East African aridity. A linear combination of time series describing the Pacific Decadal Oscillation and the strength of Indo-Pacific warming are shown to track East African rainfall reasonably well. The talk concludes with a few thoughts linking the potentially important interplay of attribution and prediction. At least for recent East African droughts, it appears that a characteristic Indo-Pacific SST and precipitation anomaly pattern can be linked statistically to support forecasts and attribution analyses. The combination of traditional AGCM attribution analyses with simple yet physically plausible statistical estimation procedures may help us better untangle some climate mysteries.
Intelligence, birth order, and family size.
Kanazawa, Satoshi
2012-09-01
The analysis of the National Child Development Study in the United Kingdom (n = 17,419) replicates some earlier findings and shows that genuine within-family data are not necessary to make the apparent birth-order effect on intelligence disappear. Birth order is not associated with intelligence in between-family data once the number of siblings is statistically controlled. The analyses support the admixture hypothesis, which avers that the apparent birth-order effect on intelligence is an artifact of family size, and cast doubt on the confluence and resource dilution models, both of which claim that birth order has a causal influence on children's cognitive development. The analyses suggest that birth order has no genuine causal effect on general intelligence.
Zheng, Jie; Harris, Marcelline R; Masci, Anna Maria; Lin, Yu; Hero, Alfred; Smith, Barry; He, Yongqun
2016-09-14
Statistics play a critical role in biological and clinical research. However, most reports of scientific results in the published literature make it difficult for the reader to reproduce the statistical analyses performed in achieving those results because they provide inadequate documentation of the statistical tests and algorithms applied. The Ontology of Biological and Clinical Statistics (OBCS) is put forward here as a step towards solving this problem. The terms in OBCS including 'data collection', 'data transformation in statistics', 'data visualization', 'statistical data analysis', and 'drawing a conclusion based on data', cover the major types of statistical processes used in basic biological research and clinical outcome studies. OBCS is aligned with the Basic Formal Ontology (BFO) and extends the Ontology of Biomedical Investigations (OBI), an OBO (Open Biological and Biomedical Ontologies) Foundry ontology supported by over 20 research communities. Currently, OBCS comprehends 878 terms, representing 20 BFO classes, 403 OBI classes, 229 OBCS specific classes, and 122 classes imported from ten other OBO ontologies. We discuss two examples illustrating how the ontology is being applied. In the first (biological) use case, we describe how OBCS was applied to represent the high throughput microarray data analysis of immunological transcriptional profiles in human subjects vaccinated with an influenza vaccine. In the second (clinical outcomes) use case, we applied OBCS to represent the processing of electronic health care data to determine the associations between hospital staffing levels and patient mortality. Our case studies were designed to show how OBCS can be used for the consistent representation of statistical analysis pipelines under two different research paradigms. Other ongoing projects using OBCS for statistical data processing are also discussed. The OBCS source code and documentation are available at: https://github.com/obcs/obcs . The Ontology of Biological and Clinical Statistics (OBCS) is a community-based open source ontology in the domain of biological and clinical statistics. OBCS is a timely ontology that represents statistics-related terms and their relations in a rigorous fashion, facilitates standard data analysis and integration, and supports reproducible biological and clinical research.
A model for effective planning of SME support services.
Rakićević, Zoran; Omerbegović-Bijelović, Jasmina; Lečić-Cvetković, Danica
2016-02-01
This paper presents a model for effective planning of support services for small and medium-sized enterprises (SMEs). The idea is to scrutinize and measure the suitability of support services in order to give recommendations for the improvement of a support planning process. We examined the applied support services and matched them with the problems and needs of SMEs, based on the survey conducted in 2013 on a sample of 336 SMEs in Serbia. We defined and analysed the five research questions that refer to support services, their consistency with the SMEs' problems and needs, and the relation between the given support and SMEs' success. The survey results have shown a statistically significant connection between them. Based on this result, we proposed an eight-phase model as a method for the improvement of support service planning for SMEs. This model helps SMEs to plan better their requirements in terms of support; government and administration bodies at all levels and organizations that provide support services to understand better SMEs' problems and needs for support. Copyright © 2015 Elsevier Ltd. All rights reserved.
Semmelweis and the aetiology of puerperal sepsis 160 years on: an historical review
NOAKES, T. D.; BORRESEN, J.; HEW-BUTLER, T.; LAMBERT, M. I.; JORDAAN, E.
2008-01-01
SUMMARY It is generally accepted that Professor Ignaz Semmelweis was the first to identify the mode of transmission of puerperal sepsis. However no appropriate statistical analysis of Semmelweis's data supporting his theory has been reported. Mean annual percent maternal mortality rates for the Allgemeines Krankenhaus and Dublin Maternity Hospitals (1784–1858) were analysed. The introduction of pathological anatomy at the Allgemeines Krankenhaus in 1823 was associated with increased mortality. After 1840 maternal mortality was higher in Clinic 1 which was staffed by male obstetricians and medical students who, unlike the midwives in Clinic 2, attended autopsies. The introduction of chlorine washing of the male clinicians’ hands in Clinic 1 by Semmelweis in 1847 reduced mortality, whereas the cessation of handwashing after Semmelweis left Vienna in 1850 was associated with increased mortality. This statistical analysis supports Semmelweis's hypothesis that ‘the cadaveric particles adhering to the hand had … caused the preponderant mortality in the first Clinic’. PMID:17553179
Sembajwe, Grace; Tveito, Torill Helene; Hopcia, Karen; Kenwood, Christopher; O'Day, Elizabeth Tucker; Stoddard, Anne M; Dennerlein, Jack T; Hashimoto, Dean; Sorensen, Glorian
2013-03-01
The aim of this study was to assess the relationship between psychosocial factors at work and multi-site musculoskeletal pain among patient care workers. In a survey of 1,572 workers from two hospitals, occupational psychosocial factors and health outcomes of workers with single and multi-site pain were evaluated using items from the Job Content Questionnaire that was designed to measure psychological demands, decision latitude, and social support. An adapted Nordic Questionnaire provided data on the musculoskeletal pain outcome. Covariates included body mass index, age, gender, and occupation. The analyses revealed statistically significant associations between psychosocial demands and multi-site musculoskeletal pain among patient care associates, nurses, and administrative personnel, both men and women. Supervisor support played a significant role for nurses and women. These results remained statistically significant after adjusting for covariates. These results highlight the associations between workplace psychosocial strain and multi-site musculoskeletal pain, setting the stage for future longitudinal explorations. Copyright 2013, SLACK Incorporated.
HydroApps: An R package for statistical simulation to use in regional analysis
NASA Astrophysics Data System (ADS)
Ganora, D.
2013-12-01
The HydroApps package is a newborn R extension initially developed to support the use of a recent model for flood frequency estimation developed for applications in Northwestern Italy; it also contains some general tools for regional analyses and can be easily extended to include other statistical models. The package is currently at an experimental level of development. The HydroApps is a corollary of the SSEM project for regional flood frequency analysis, although it was developed independently to support various instances of regional analyses. Its aim is to provide a basis for interplay between statistical simulation and practical operational use. In particular, the main module of the package deals with the building of the confidence bands of flood frequency curves expressed by means of their L-moments. Other functions include pre-processing and visualization of hydrologic time series, analysis of the optimal design-flood under uncertainty, but also tools useful in water resources management for the estimation of flow duration curves and their sensitivity to water withdrawals. Particular attention is devoted to the code granularity, i.e. the level of detail and aggregation of the code: a greater detail means more low-level functions, which entails more flexibility but reduces the ease of use for practical use. A balance between detail and simplicity is necessary and can be resolved with appropriate wrapping functions and specific help pages for each working block. From a more general viewpoint, the package has not really and user-friendly interface, but runs on multiple operating systems and it's easy to update, as many other open-source projects., The HydroApps functions and their features are reported in order to share ideas and materials to improve the ';technological' and information transfer between scientist communities and final users like policy makers.
Statistical analyses support power law distributions found in neuronal avalanches.
Klaus, Andreas; Yu, Shan; Plenz, Dietmar
2011-01-01
The size distribution of neuronal avalanches in cortical networks has been reported to follow a power law distribution with exponent close to -1.5, which is a reflection of long-range spatial correlations in spontaneous neuronal activity. However, identifying power law scaling in empirical data can be difficult and sometimes controversial. In the present study, we tested the power law hypothesis for neuronal avalanches by using more stringent statistical analyses. In particular, we performed the following steps: (i) analysis of finite-size scaling to identify scale-free dynamics in neuronal avalanches, (ii) model parameter estimation to determine the specific exponent of the power law, and (iii) comparison of the power law to alternative model distributions. Consistent with critical state dynamics, avalanche size distributions exhibited robust scaling behavior in which the maximum avalanche size was limited only by the spatial extent of sampling ("finite size" effect). This scale-free dynamics suggests the power law as a model for the distribution of avalanche sizes. Using both the Kolmogorov-Smirnov statistic and a maximum likelihood approach, we found the slope to be close to -1.5, which is in line with previous reports. Finally, the power law model for neuronal avalanches was compared to the exponential and to various heavy-tail distributions based on the Kolmogorov-Smirnov distance and by using a log-likelihood ratio test. Both the power law distribution without and with exponential cut-off provided significantly better fits to the cluster size distributions in neuronal avalanches than the exponential, the lognormal and the gamma distribution. In summary, our findings strongly support the power law scaling in neuronal avalanches, providing further evidence for critical state dynamics in superficial layers of cortex.
Ahern, Tracey; Gardner, Anne; Courtney, Mary
2016-08-01
This study investigated whether use of services of a breast care nurse (BCN) at any time during treatment for breast cancer led to reduced unmet needs and increased self-efficacy among women with breast cancer. A secondary aim was to analyse comparisons between urban and rural and remote dwellers. Participants were Australian women who completed treatment for breast cancer at least 6 months before the survey date, recruited through two national databases of women diagnosed with breast cancer. The cross-sectional online survey consisted of two well validated measures, the SCNS-SF34 and the CASE-Cancer Scale. Statistical data were analysed using SPSS, with chi-square used to measure statistical significance. A total of 902 participants responded to the survey. Unmet needs in the psychological domain were most prominent. Respondents who used the services of a BCN were significantly less likely to report unmet needs regarding tiredness, anxiety; future outlook; feelings about death and dying; patient care and support from medical staff; and provision of health systems and information. Scores of self-efficacy showed women using the services of a BCN had significantly higher self-efficacy when seeking and obtaining information (ρ ≤ 0.001) and understanding and participating in care (ρ = 0.032). Urban dwellers were more likely to have choice of health care service, but overall neither unmet needs nor perceived self-efficacy varied statistically significantly by remoteness. Women with breast cancer experience a range of unmet needs; however those using BCN services demonstrated positive outcomes in terms of decreased unmet needs and increased self-efficacy. Copyright © 2016 Elsevier Ltd. All rights reserved.
Schaid, Daniel J
2010-01-01
Measures of genomic similarity are the basis of many statistical analytic methods. We review the mathematical and statistical basis of similarity methods, particularly based on kernel methods. A kernel function converts information for a pair of subjects to a quantitative value representing either similarity (larger values meaning more similar) or distance (smaller values meaning more similar), with the requirement that it must create a positive semidefinite matrix when applied to all pairs of subjects. This review emphasizes the wide range of statistical methods and software that can be used when similarity is based on kernel methods, such as nonparametric regression, linear mixed models and generalized linear mixed models, hierarchical models, score statistics, and support vector machines. The mathematical rigor for these methods is summarized, as is the mathematical framework for making kernels. This review provides a framework to move from intuitive and heuristic approaches to define genomic similarities to more rigorous methods that can take advantage of powerful statistical modeling and existing software. A companion paper reviews novel approaches to creating kernels that might be useful for genomic analyses, providing insights with examples [1]. Copyright © 2010 S. Karger AG, Basel.
"What If" Analyses: Ways to Interpret Statistical Significance Test Results Using EXCEL or "R"
ERIC Educational Resources Information Center
Ozturk, Elif
2012-01-01
The present paper aims to review two motivations to conduct "what if" analyses using Excel and "R" to understand the statistical significance tests through the sample size context. "What if" analyses can be used to teach students what statistical significance tests really do and in applied research either prospectively to estimate what sample size…
Statistical modeling implicates neuroanatomical circuit mediating stress relief by ‘comfort’ food
Ulrich-Lai, Yvonne M.; Christiansen, Anne M.; Wang, Xia; Song, Seongho; Herman, James P.
2015-01-01
A history of eating highly-palatable foods reduces physiological and emotional responses to stress. For instance, we have previously shown that limited sucrose intake (4 ml of 30% sucrose twice daily for 14 days) reduces hypothalamic-pituitary-adrenocortical (HPA) axis responses to stress. However, the neural mechanisms underlying stress relief by such ‘comfort’ foods are unclear, and could reveal an endogenous brain pathway for stress mitigation. As such, the present work assessed the expression of several proteins related to neuronal activation and/or plasticity in multiple stress- and reward-regulatory brain regions of rats after limited sucrose (vs. water control) intake. These data were then subjected to a series of statistical analyses, including Bayesian modeling, to identify the most likely neurocircuit mediating stress relief by sucrose. The analyses suggest that sucrose reduces HPA activation by dampening an excitatory basolateral amygdala - medial amygdala circuit, while also potentiating an inhibitory bed nucleus of the stria terminalis principle subdivision-mediated circuit, resulting in reduced HPA activation after stress. Collectively, the results support the hypothesis that sucrose limits stress responses via plastic changes to the structure and function of stress-regulatory neural circuits. The work also illustrates that advanced statistical methods are useful approaches to identify potentially novel and important underlying relationships in biological data sets. PMID:26246177
Statistical modeling implicates neuroanatomical circuit mediating stress relief by 'comfort' food.
Ulrich-Lai, Yvonne M; Christiansen, Anne M; Wang, Xia; Song, Seongho; Herman, James P
2016-07-01
A history of eating highly palatable foods reduces physiological and emotional responses to stress. For instance, we have previously shown that limited sucrose intake (4 ml of 30 % sucrose twice daily for 14 days) reduces hypothalamic-pituitary-adrenocortical (HPA) axis responses to stress. However, the neural mechanisms underlying stress relief by such 'comfort' foods are unclear, and could reveal an endogenous brain pathway for stress mitigation. As such, the present work assessed the expression of several proteins related to neuronal activation and/or plasticity in multiple stress- and reward-regulatory brain regions of rats after limited sucrose (vs. water control) intake. These data were then subjected to a series of statistical analyses, including Bayesian modeling, to identify the most likely neurocircuit mediating stress relief by sucrose. The analyses suggest that sucrose reduces HPA activation by dampening an excitatory basolateral amygdala-medial amygdala circuit, while also potentiating an inhibitory bed nucleus of the stria terminalis principle subdivision-mediated circuit, resulting in reduced HPA activation after stress. Collectively, the results support the hypothesis that sucrose limits stress responses via plastic changes to the structure and function of stress-regulatory neural circuits. The work also illustrates that advanced statistical methods are useful approaches to identify potentially novel and important underlying relationships in biological datasets.
Gorgolewski, Krzysztof J; Varoquaux, Gael; Rivera, Gabriel; Schwartz, Yannick; Sochat, Vanessa V; Ghosh, Satrajit S; Maumet, Camille; Nichols, Thomas E; Poline, Jean-Baptiste; Yarkoni, Tal; Margulies, Daniel S; Poldrack, Russell A
2016-01-01
NeuroVault.org is dedicated to storing outputs of analyses in the form of statistical maps, parcellations and atlases, a unique strategy that contrasts with most neuroimaging repositories that store raw acquisition data or stereotaxic coordinates. Such maps are indispensable for performing meta-analyses, validating novel methodology, and deciding on precise outlines for regions of interest (ROIs). NeuroVault is open to maps derived from both healthy and clinical populations, as well as from various imaging modalities (sMRI, fMRI, EEG, MEG, PET, etc.). The repository uses modern web technologies such as interactive web-based visualization, cognitive decoding, and comparison with other maps to provide researchers with efficient, intuitive tools to improve the understanding of their results. Each dataset and map is assigned a permanent Universal Resource Locator (URL), and all of the data is accessible through a REST Application Programming Interface (API). Additionally, the repository supports the NIDM-Results standard and has the ability to parse outputs from popular FSL and SPM software packages to automatically extract relevant metadata. This ease of use, modern web-integration, and pioneering functionality holds promise to improve the workflow for making inferences about and sharing whole-brain statistical maps. Copyright © 2015 Elsevier Inc. All rights reserved.
Terides, Matthew D; Dear, Blake F; Fogliati, Vincent J; Gandy, Milena; Karin, Eyal; Jones, Michael P; Titov, Nickolai
2018-01-01
Cognitive-behavioural therapy (CBT) is an effective treatment for clinical and subclinical symptoms of depression and general anxiety, and increases life satisfaction. Patients' usage of CBT skills is a core aspect of treatment but there is insufficient empirical evidence suggesting that skills usage behaviours are a mechanism of clinical change. This study investigated if an internet-delivered CBT (iCBT) intervention increased the frequency of CBT skills usage behaviours and if this statistically mediated reductions in symptoms and increased life satisfaction. A two-group randomised controlled trial was conducted comparing internet-delivered CBT (n = 65) with a waitlist control group (n = 75). Participants were individuals experiencing clinically significant symptoms of depression or general anxiety. Mixed-linear models analyses revealed that the treatment group reported a significantly higher frequency of skills usage, lower symptoms, and higher life satisfaction by the end of treatment compared with the control group. Results from bootstrapping mediation analyses revealed that the increased skills usage behaviours statistically mediated symptom reductions and increased life satisfaction. Although skills usage and symptom outcomes were assessed concurrently, these findings support the notion that iCBT increases the frequency of skills usage behaviours and suggest that this may be an important mechanism of change.
Social integration of Latin-American immigrants in Spain: the influence of the community context.
Fuente, Asur; Herrero, Juan
2012-11-01
The main goal of this study is to analyze the degree to which several community elements such as insecurity, discrimination and informal community support might have an influence on the social integration of Latin-American immigrants, a group at risk of social exclusion in Spain. Multivariate linear regression analyses results showed that informal community support is positively related to social integration whereas insecurity is negatively related. The statistical relationship between discrimination and social integration disappears once levels of informal community support are taken into account. A better understanding of the factors that either promote or inhibit the social integration progress of immigrant population is important to orientate public policies and intervention programs that contribute to the adaptation of this population to the host society.
Chae, Sun-Mi; Park, Jee Won; Kang, Hee Sun
2014-04-01
Promoting the health-related quality of life (HRQOL) is an important aim of nursing care for immigrant women. The aim of this study was to evaluate the level of HRQOL and its relationships with social support, acculturative stress, and depression among Vietnamese immigrant women. A total of 216 Vietnamese immigrant women residing in South Korea participated in the study. Participants completed a series of questionnaires, including measures of social support, acculturative stress, depression, and HRQOL. For statistical analyses, a path analysis was applied. Social support, acculturative stress, depression, and HRQOL were interrelated. Acculturative stress and depression directly influenced the mental health component of HRQOL, whereas social support indirectly influenced HRQOL through acculturative stress and depression. Only depression directly influenced the physical health component of HRQOL. Results suggest that social support and acculturative stress are related factors in preventing depression and promoting HRQOL, especially mental health, among Vietnamese immigrant women.
Efficace, Fabio; Breccia, Massimo; Cottone, Francesco; Okumura, Iris; Doro, Maribel; Riccardi, Francesca; Rosti, Gianantonio; Baccarani, Michele
2016-12-01
The main objective of this study was to investigate whether social support is independently associated with psychological well-being in chronic myeloid leukemia (CML) patients. Secondary objectives were to compare the psychological well-being profile of CML patients with that of their peers in general population and to examine possible age- and sex-related differences. Analysis was performed on 417 patients in treatment with lifelong molecularly targeted therapies. Mean age of patients analyzed was 56 years (range 19-87 years) and 247 (59 %) were male and 170 (41 %) were female. Social support was assessed with the Multidimensional Scale of Perceived Social Support and psychological well-being was evaluated with the short version of the Psychological General Well-Being Index. Descriptive statistics and multivariate logistic regression analyses were used. Multivariate logistic regression analysis revealed that a greater social support was independently associated with lower anxiety and depression, as well as with higher positive well-being, self-control, and vitality (p < 0.001). Female patients reported statistically significant worse outcomes in all dimensions of psychological well-being. Age- and sex-adjusted comparisons with population norms revealed that depression (ES = -0.42, p < 0.001) and self-control (ES = -0.48, p < 0.001) were the two main impaired psychological dimensions. This study indicates that social support is a critical factor associated with psychological well-being of CML patients treated with modern lifelong targeted therapies.
Vesterinen, Hanna M; Vesterinen, Hanna V; Egan, Kieren; Deister, Amelie; Schlattmann, Peter; Macleod, Malcolm R; Dirnagl, Ulrich
2011-04-01
Translating experimental findings into clinically effective therapies is one of the major bottlenecks of modern medicine. As this has been particularly true for cerebrovascular research, attention has turned to the quality and validity of experimental cerebrovascular studies. We set out to assess the study design, statistical analyses, and reporting of cerebrovascular research. We assessed all original articles published in the Journal of Cerebral Blood Flow and Metabolism during the year 2008 against a checklist designed to capture the key attributes relating to study design, statistical analyses, and reporting. A total of 156 original publications were included (animal, in vitro, human). Few studies reported a primary research hypothesis, statement of purpose, or measures to safeguard internal validity (such as randomization, blinding, exclusion or inclusion criteria). Many studies lacked sufficient information regarding methods and results to form a reasonable judgment about their validity. In nearly 20% of studies, statistical tests were either not appropriate or information to allow assessment of appropriateness was lacking. This study identifies a number of factors that should be addressed if the quality of research in basic and translational biomedicine is to be improved. We support the widespread implementation of the ARRIVE (Animal Research Reporting In Vivo Experiments) statement for the reporting of experimental studies in biomedicine, for improving training in proper study design and analysis, and that reviewers and editors adopt a more constructively critical approach in the assessment of manuscripts for publication.
Vesterinen, Hanna V; Egan, Kieren; Deister, Amelie; Schlattmann, Peter; Macleod, Malcolm R; Dirnagl, Ulrich
2011-01-01
Translating experimental findings into clinically effective therapies is one of the major bottlenecks of modern medicine. As this has been particularly true for cerebrovascular research, attention has turned to the quality and validity of experimental cerebrovascular studies. We set out to assess the study design, statistical analyses, and reporting of cerebrovascular research. We assessed all original articles published in the Journal of Cerebral Blood Flow and Metabolism during the year 2008 against a checklist designed to capture the key attributes relating to study design, statistical analyses, and reporting. A total of 156 original publications were included (animal, in vitro, human). Few studies reported a primary research hypothesis, statement of purpose, or measures to safeguard internal validity (such as randomization, blinding, exclusion or inclusion criteria). Many studies lacked sufficient information regarding methods and results to form a reasonable judgment about their validity. In nearly 20% of studies, statistical tests were either not appropriate or information to allow assessment of appropriateness was lacking. This study identifies a number of factors that should be addressed if the quality of research in basic and translational biomedicine is to be improved. We support the widespread implementation of the ARRIVE (Animal Research Reporting In Vivo Experiments) statement for the reporting of experimental studies in biomedicine, for improving training in proper study design and analysis, and that reviewers and editors adopt a more constructively critical approach in the assessment of manuscripts for publication. PMID:21157472
NASA Technical Reports Server (NTRS)
Nahra, Henry K.; Christiansen, Eric; Piekutowski, Andrew; Lyons, Frankel; Keddy, Christopher; Salem, Jonathan; Miller, Joshua; Bohl, William; Poormon, Kevin; Greene, Nathanel;
2010-01-01
Hypervelocity impacts were performed on six unstressed and six stressed titanium coupons with aluminium shielding in order to assess the effects of the partial penetration damage on the post impact micromechanical properties of titanium and on the residual strength after impact. This work is performed in support of the definition of the penetration criteria of the propellant tanks surfaces for the service module of the crew exploration vehicle where such a criterion is based on testing and analyses rather than on historical precedence. The objective of this work is to assess the effects of applied biaxial stress on the damage dynamics and morphology. The crater statistics revealed minute differences between stressed and unstressed coupon damage. The post impact residual stress analyses showed that the titanium strength properties were generally unchanged for the unstressed coupons when compared with undamaged titanium. However, high localized strains were shown near the craters during the tensile tests.
NASA Technical Reports Server (NTRS)
Nahra, Henry K.; Christiansen, Eric; Piekutowski, Andrew; Lyons, Frankel; Keddy, Christopher; Salem, Jonathan; Poormon, Kevin; Bohl, William; Miller, Joshua; Greene, Nathanael;
2010-01-01
Hypervelocity impacts were performed on six unstressed and six stressed titanium coupons with aluminium: shielding in order to assess the effects of the partial penetration damage on the post impact micromechanical properties of titanium and on the residual strength after impact. This work is performed in support of the defInition of the penetration criteria of the propellant and oxidizer tanks dome surfaces for the service module of the crew exploration vehicle where such a criterion is based on testing and analyses rather than on historical precedence. The objective of this work is to assess the effects of applied biaxial stress on the damage dynamics and morphology. The crater statistics revealed minute differences between stressed and unstressed coupon damage. The post impact residual stress analyses showed that the titanium strength properties were generally unchanged for the unstressed coupons when compared with undamaged titanium. However, high localized strains were shown near the craters during the tensile tests.
Villa-Uriol, M. C.; Berti, G.; Hose, D. R.; Marzo, A.; Chiarini, A.; Penrose, J.; Pozo, J.; Schmidt, J. G.; Singh, P.; Lycett, R.; Larrabide, I.; Frangi, A. F.
2011-01-01
Cerebral aneurysms are a multi-factorial disease with severe consequences. A core part of the European project @neurIST was the physical characterization of aneurysms to find candidate risk factors associated with aneurysm rupture. The project investigated measures based on morphological, haemodynamic and aneurysm wall structure analyses for more than 300 cases of ruptured and unruptured aneurysms, extracting descriptors suitable for statistical studies. This paper deals with the unique challenges associated with this task, and the implemented solutions. The consistency of results required by the subsequent statistical analyses, given the heterogeneous image data sources and multiple human operators, was met by a highly automated toolchain combined with training. A testimonial of the successful automation is the positive evaluation of the toolchain by over 260 clinicians during various hands-on workshops. The specification of the analyses required thorough investigations of modelling and processing choices, discussed in a detailed analysis protocol. Finally, an abstract data model governing the management of the simulation-related data provides a framework for data provenance and supports future use of data and toolchain. This is achieved by enabling the easy modification of the modelling approaches and solution details through abstract problem descriptions, removing the need of repetition of manual processing work. PMID:22670202
Su, Junhu; Ji, Weihong; Wei, Yanming; Zhang, Yanping; Gleeson, Dianne M; Lou, Zhongyu; Ren, Jing
2014-08-01
The endangered schizothoracine fish Gymnodiptychus pachycheilus is endemic to the Qinghai-Tibetan Plateau (QTP), but very little genetic information is available for this species. Here, we accessed the current genetic divergence of G. pachycheilus population to evaluate their distributions modulated by contemporary and historical processes. Population structure and demographic history were assessed by analyzing 1811-base pairs of mitochondrial DNA from 61 individuals across a large proportion of its geographic range. Our results revealed low nucleotide diversity, suggesting severe historical bottleneck events. Analyses of molecular variance and the conventional population statistic FST (0.0435, P = 0.0215) confirmed weak genetic structure. The monophyly of G. pachycheilus was statistically well-supported, while two divergent evolutionary clusters were identified by phylogenetic analyses, suggesting a microgeographic population structure. The consistent scenario of recent population expansion of two clusters was identified based on several complementary analyses of demographic history (0.096 Ma and 0.15 Ma). This genetic divergence and evolutionary process are likely to have resulted from a series of drainage arrangements triggered by the historical tectonic events of the region. The results obtained here provide the first insights into the evolutionary history and genetic status of this little-known fish.
NASA Astrophysics Data System (ADS)
Kaleva Oikarinen, Juho; Järvelä, Sanna; Kaasila, Raimo
2014-04-01
This design-based research project focuses on documenting statistical learning among 16-17-year-old Finnish upper secondary school students (N = 78) in a computer-supported collaborative learning (CSCL) environment. One novel value of this study is in reporting the shift from teacher-led mathematical teaching to autonomous small-group learning in statistics. The main aim of this study is to examine how student collaboration occurs in learning statistics in a CSCL environment. The data include material from videotaped classroom observations and the researcher's notes. In this paper, the inter-subjective phenomena of students' interactions in a CSCL environment are analysed by using a contact summary sheet (CSS). The development of the multi-dimensional coding procedure of the CSS instrument is presented. Aptly selected video episodes were transcribed and coded in terms of conversational acts, which were divided into non-task-related and task-related categories to depict students' levels of collaboration. The results show that collaborative learning (CL) can facilitate cohesion and responsibility and reduce students' feelings of detachment in our classless, periodic school system. The interactive .pdf material and collaboration in small groups enable statistical learning. It is concluded that CSCL is one possible method of promoting statistical teaching. CL using interactive materials seems to foster and facilitate statistical learning processes.
Sul, Jae Hoon; Bilow, Michael; Yang, Wen-Yun; Kostem, Emrah; Furlotte, Nick; He, Dan; Eskin, Eleazar
2016-03-01
Although genome-wide association studies (GWASs) have discovered numerous novel genetic variants associated with many complex traits and diseases, those genetic variants typically explain only a small fraction of phenotypic variance. Factors that account for phenotypic variance include environmental factors and gene-by-environment interactions (GEIs). Recently, several studies have conducted genome-wide gene-by-environment association analyses and demonstrated important roles of GEIs in complex traits. One of the main challenges in these association studies is to control effects of population structure that may cause spurious associations. Many studies have analyzed how population structure influences statistics of genetic variants and developed several statistical approaches to correct for population structure. However, the impact of population structure on GEI statistics in GWASs has not been extensively studied and nor have there been methods designed to correct for population structure on GEI statistics. In this paper, we show both analytically and empirically that population structure may cause spurious GEIs and use both simulation and two GWAS datasets to support our finding. We propose a statistical approach based on mixed models to account for population structure on GEI statistics. We find that our approach effectively controls population structure on statistics for GEIs as well as for genetic variants.
CSB: a Python framework for structural bioinformatics.
Kalev, Ivan; Mechelke, Martin; Kopec, Klaus O; Holder, Thomas; Carstens, Simeon; Habeck, Michael
2012-11-15
Computational Structural Biology Toolbox (CSB) is a cross-platform Python class library for reading, storing and analyzing biomolecular structures with rich support for statistical analyses. CSB is designed for reusability and extensibility and comes with a clean, well-documented API following good object-oriented engineering practice. Stable release packages are available for download from the Python Package Index (PyPI) as well as from the project's website http://csb.codeplex.com. ivan.kalev@gmail.com or michael.habeck@tuebingen.mpg.de
NASA Technical Reports Server (NTRS)
Neustadter, H. E.; King, R. B.; Fordyce, J. S.; Burr, J. C., Jr.
1972-01-01
The NASA Lewis Research Center is assisting the City of Cleveland, Ohio, in its effort to monitor its air pollution. This report describes the Cleveland program of the past 4 years and the supportive Lewis program currently being developed. The data accumulated by Cleveland over the past 4 years are presented together with some preliminary statistical analyses indicating in a semiquantitive manner the degree of air pollution existing within the boundaries of Cleveland.
Effects of Whole and Partial Body Exposure to Dry Heat on Certain Performance Measures.
1981-05-01
Robert Bachert who assisted with the statistical analyses; and he acknowledges the support of the Lite Mr. George C. Frost for his advice on the...of the study and interpretation of data: Dr. Arthur L Dudycha, Dr. Barry H. Kantowitz, Dr. N. M. Downie, Dr. Ernest J. McCormick, and Dr. Robert D...D., Summers, W. C., & Smedley , D. C., November 1974, Evaluation of a water- cooled helmet liner (AMRL-TR-74-135). Aerospace Medical Research
1989-04-01
Hill and Susan Bodilly were incorporated into this report. Todd Porter, a RAND Summer Intern, contributed to the data development, statistical...5Bailey and Lawrence , 1987, pp. 19-20. The R&D tax credit allowed a 25 percent credit for R&D expenditures in excess of the average amount spent...See J. A. Hausman , ’Specificaticn Tests in Econometrics,"Econormetrica, Vol, 46, No. 6, November 1978. 61 (7) and (8) report the results of this
Beeman, John; Hansel, Hal; Perry, Russell; Hockersmith, Eric; Sandford, Ben
2011-01-01
This report describes analyses of data from radio- or acoustic-tagged juvenile salmonids passing through hydro-dam turbines to determine factors affecting fish survival. The data were collected during a series of studies designed to estimate passage and survival probabilities at McNary (2002-09) and John Day (2002-03) Dams on the Columbia River during controlled experiments of structures or operations at spillways. Relatively few tagged fish passed turbines in any single study, but sample sizes generally were adequate for our analyses when data were combined from studies using common methods over a series of years. We used information-theoretic methods to evaluate biological, operational, and group covariates by creating models fitting linear (all covariates) or curvilinear (operational covariates only) functions to the data. Biological covariates included tag burden, weight, and water temperature; operational covariates included spill percentage, total discharge, hydraulic head, and turbine unit discharge; and group covariates included year, treatment, and photoperiod. Several interactions between the variables also were considered. Support of covariates by the data was assessed by comparing the Akaike Information Criterion of competing models. The analyses were conducted because there was a lack of information about factors affecting survival of fish passing turbines volitionally and the data were available from past studies. The depth of acclimation, tag size relative to fish size (tag burden), turbine unit discharge, and area of entry into the turbine intake have been shown to affect turbine passage survival of juvenile salmonids in other studies. This study indicates that turbine passage survival of the study fish was primarily affected by biological covariates rather than operational covariates. A negative effect of tag burden was strongly supported in data from yearling Chinook salmon at John Day and McNary dams, but not for subyearling Chinook salmon or juvenile steelhead. The negative effect of tag burden in data we examined from yearling Chinook salmon supports the recent findings from laboratory studies of barotrauma effects. A curvilinear (quadratic) effect of turbine unit discharge was weakly supported in data from subyearling Chinook salmon at John Day Dam. The maximum survival from those data was estimated to occur at a discharge of 15.9 thousand cubic feet per second, but the estimate was imprecise (95 percent confidence interval of -1.7-33.7 thousand cubic feet per second). This estimate is within the range of 1 percent of peak turbine operating efficiency (12.0-21.6 thousand cubic feet per second), but is lower than the 17.2 thousand cubic feet per second discharge at peak operating efficiency (at a head of 102 feet near the median in the data we examined). Effects of water temperature were supported in four of the five examined data sets and were strongly supported in all but one. Spill percentage, head, and total discharge received weak or moderate support in some cases. The results are consistent with those of several controlled field experiments of turbine discharge. Studies based on the Hi-Z Turb'N tag (balloon tag) often show small, generally statistically insignificant, differences in survival at different turbine discharge levels. Some studies also show that a quadratic equation can be well fit to the relation of survival and turbine unit discharge. The lack of support for the operational covariates in most of the data sets we examined may be due to the small effect turbine discharge has even in controlled studies, the observational nature of the data we used, and the evaluation method. We assessed support of the data for models of linear and quadratic effects, whereas controlled experiments often statistically compare the point estimates of survival from each operational treatment studied. The results of our analyses suggest tag burden should be minimized or controlled for in analyses of future stu
NASA Astrophysics Data System (ADS)
Khatri, Ayisha Al; Jens, Grundmann; der Weth Rüdiger, van; Niels, Schütze
2015-04-01
Al Batinah coastal area is the main agricultural region in Oman. Agriculture is concentrated in Al Batinah, because of more fertile soils and easier access to water in the form of groundwater compared to other administrative areas in the country. The region now is facing a problem as a result of over abstraction of fresh groundwater for irrigation from the main aquifer along the coast. This enforces the inflow of sea water into the coastal aquifer and causes salinization of the groundwater. As a consequence the groundwater becomes no longer suitable for irrigation which impacts the social and economical situation of farmers as well as the environment. Therefore, the existing situation generates conflicts between different stakeholders regarding water availability, sustainable aquifer management, and profitable agricultural production in Al Batinah region. Several management measures to maintain the groundwater aquifer in the region, were implemented by the government. However, these solutions showed only limited successes for the existing problem. The aim of this study now is to evaluate the implementation potential of several management interventions and their combinations by analysing opinions and responses of all relevant stakeholders in the region. This is done in order to identify potential conflicts among stakeholders to a participatory process within the frame of an integrated water resources management and to support decision makers in taking more informed decisions. Questionnaires were designed for collecting data from different groups of stakeholders e.g. water professionals, farmers from the study area and decision makers of different organizations and ministries. These data were analysed statistically for each group separately as well as regarding relations amongst groups by using the SPSS (Statistical Package for Social Science) software package. Results show, that the need to improve the situation is supported by all groups. However, significant differences exist between groups on how to achieve this improvement, since farmers prefer management interventions operating more on the water resources side while decision makers support measures for a better management on the water demand side. Furthermore, the opinions within single groups are sometimes contradicting for several management interventions. The use of more advanced statistical methods like discriminant analysis or Bayesian network allow for identifying factors and drivers to explain these differences. Both approaches, will help to understand stakeholder's behaviours and to evaluate the implementation potential of several management interventions. Keywords IWRM, Stakeholder participation, field survey, statistical analysis, Oman
Developing family-centred care in a neonatal intensive care unit: An action research study.
Skene, Caryl; Gerrish, Kate; Price, Fiona; Pilling, Elizabeth; Bayliss, Pauline; Gillespie, Siobhan
2018-06-21
To develop, implement and evaluate family-centred interventions to promote parental involvement in caregiving in a Neonatal Intensive Care Unit. A participatory action research approach was used to implement two changes in practice a) improved skin-to-skin contact b) unlimited parental presence at the cot-side. The changes were underpinned by a family-centred philosophy of care and education. Data were collected from staff using a questionnaire, focus groups and interviews, and from parents using focus groups and interviews. Qualitative data were analysed using Framework and quantitative data analysed using descriptive and t-test statistics. A Neonatal Intensive Care Unit in England. Changes in practice were successfully implemented. Nurses reported positively on improvements in Family Centred Care; most notably information-sharing with parents, providing family support, enabling parental participation in care and improved competence supporting parents in care-giving. These changes were reflected in parental feedback. Understanding the context of the neonatal unit can support cultural change when change is actively facilitated and owned by the staff concerned. Acknowledging parents as the main caregiver can be challenging for nurses and they require support and education to enable them to manage the changes necessary to provide Family-Centred Care. Copyright © 2018 Elsevier Ltd. All rights reserved.
Coloc-stats: a unified web interface to perform colocalization analysis of genomic features.
Simovski, Boris; Kanduri, Chakravarthi; Gundersen, Sveinung; Titov, Dmytro; Domanska, Diana; Bock, Christoph; Bossini-Castillo, Lara; Chikina, Maria; Favorov, Alexander; Layer, Ryan M; Mironov, Andrey A; Quinlan, Aaron R; Sheffield, Nathan C; Trynka, Gosia; Sandve, Geir K
2018-06-05
Functional genomics assays produce sets of genomic regions as one of their main outputs. To biologically interpret such region-sets, researchers often use colocalization analysis, where the statistical significance of colocalization (overlap, spatial proximity) between two or more region-sets is tested. Existing colocalization analysis tools vary in the statistical methodology and analysis approaches, thus potentially providing different conclusions for the same research question. As the findings of colocalization analysis are often the basis for follow-up experiments, it is helpful to use several tools in parallel and to compare the results. We developed the Coloc-stats web service to facilitate such analyses. Coloc-stats provides a unified interface to perform colocalization analysis across various analytical methods and method-specific options (e.g. colocalization measures, resolution, null models). Coloc-stats helps the user to find a method that supports their experimental requirements and allows for a straightforward comparison across methods. Coloc-stats is implemented as a web server with a graphical user interface that assists users with configuring their colocalization analyses. Coloc-stats is freely available at https://hyperbrowser.uio.no/coloc-stats/.
Harrison, Jay M; Breeze, Matthew L; Harrigan, George G
2011-08-01
Statistical comparisons of compositional data generated on genetically modified (GM) crops and their near-isogenic conventional (non-GM) counterparts typically rely on classical significance testing. This manuscript presents an introduction to Bayesian methods for compositional analysis along with recommendations for model validation. The approach is illustrated using protein and fat data from two herbicide tolerant GM soybeans (MON87708 and MON87708×MON89788) and a conventional comparator grown in the US in 2008 and 2009. Guidelines recommended by the US Food and Drug Administration (FDA) in conducting Bayesian analyses of clinical studies on medical devices were followed. This study is the first Bayesian approach to GM and non-GM compositional comparisons. The evaluation presented here supports a conclusion that a Bayesian approach to analyzing compositional data can provide meaningful and interpretable results. We further describe the importance of method validation and approaches to model checking if Bayesian approaches to compositional data analysis are to be considered viable by scientists involved in GM research and regulation. Copyright © 2011 Elsevier Inc. All rights reserved.
Blueprint XAS: a Matlab-based toolbox for the fitting and analysis of XAS spectra.
Delgado-Jaime, Mario Ulises; Mewis, Craig Philip; Kennepohl, Pierre
2010-01-01
Blueprint XAS is a new Matlab-based program developed to fit and analyse X-ray absorption spectroscopy (XAS) data, most specifically in the near-edge region of the spectrum. The program is based on a methodology that introduces a novel background model into the complete fit model and that is capable of generating any number of independent fits with minimal introduction of user bias [Delgado-Jaime & Kennepohl (2010), J. Synchrotron Rad. 17, 119-128]. The functions and settings on the five panels of its graphical user interface are designed to suit the needs of near-edge XAS data analyzers. A batch function allows for the setting of multiple jobs to be run with Matlab in the background. A unique statistics panel allows the user to analyse a family of independent fits, to evaluate fit models and to draw statistically supported conclusions. The version introduced here (v0.2) is currently a toolbox for Matlab. Future stand-alone versions of the program will also incorporate several other new features to create a full package of tools for XAS data processing.
Trull, Timothy J.; Vergés, Alvaro; Wood, Phillip K.; Jahng, Seungmin; Sher, Kenneth J.
2013-01-01
We examined the latent structure underlying the criteria for DSM–IV–TR (American Psychiatric Association, 2000, Diagnostic and statistical manual of mental disorders (4th ed., text revision). Washington, DC: Author.) personality disorders in a large nationally representative sample of U.S. adults. Personality disorder symptom data were collected using a structured diagnostic interview from approximately 35,000 adults assessed over two waves of data collection in the National Epidemiologic Survey on Alcohol and Related Conditions. Our analyses suggested that a seven-factor solution provided the best fit for the data, and these factors were marked primarily by one or at most two personality disorder criteria sets. A series of regression analyses that used external validators tapping Axis I psychopathology, treatment for mental health problems, functioning scores, interpersonal conflict, and suicidal ideation and behavior provided support for the seven-factor solution. We discuss these findings in the context of previous studies that have examined the structure underlying the personality disorder criteria as well as the current proposals for DSM-5 personality disorders. PMID:22506626
Practice-based evidence study design for comparative effectiveness research.
Horn, Susan D; Gassaway, Julie
2007-10-01
To describe a new, rigorous, comprehensive practice-based evidence for clinical practice improvement (PBE-CPI) study methodology, and compare its features, advantages, and disadvantages to those of randomized controlled trials and sophisticated statistical methods for comparative effectiveness research. PBE-CPI incorporates natural variation within data from routine clinical practice to determine what works, for whom, when, and at what cost. It uses the knowledge of front-line caregivers, who develop study questions and define variables as part of a transdisciplinary team. Its comprehensive measurement framework provides a basis for analyses of significant bivariate and multivariate associations between treatments and outcomes, controlling for patient differences, such as severity of illness. PBE-CPI studies can uncover better practices more quickly than randomized controlled trials or sophisticated statistical methods, while achieving many of the same advantages. We present examples of actionable findings from PBE-CPI studies in postacute care settings related to comparative effectiveness of medications, nutritional support approaches, incontinence products, physical therapy activities, and other services. Outcomes improved when practices associated with better outcomes in PBE-CPI analyses were adopted in practice.
Large-scale replication study reveals a limit on probabilistic prediction in language comprehension.
Nieuwland, Mante S; Politzer-Ahles, Stephen; Heyselaar, Evelien; Segaert, Katrien; Darley, Emily; Kazanina, Nina; Von Grebmer Zu Wolfsthurn, Sarah; Bartolozzi, Federica; Kogan, Vita; Ito, Aine; Mézière, Diane; Barr, Dale J; Rousselet, Guillaume A; Ferguson, Heather J; Busch-Moreno, Simon; Fu, Xiao; Tuomainen, Jyrki; Kulakova, Eugenia; Husband, E Matthew; Donaldson, David I; Kohút, Zdenko; Rueschemeyer, Shirley-Ann; Huettig, Falk
2018-04-03
Do people routinely pre-activate the meaning and even the phonological form of upcoming words? The most acclaimed evidence for phonological prediction comes from a 2005 Nature Neuroscience publication by DeLong, Urbach and Kutas, who observed a graded modulation of electrical brain potentials (N400) to nouns and preceding articles by the probability that people use a word to continue the sentence fragment ('cloze'). In our direct replication study spanning 9 laboratories ( N =334), pre-registered replication-analyses and exploratory Bayes factor analyses successfully replicated the noun-results but, crucially, not the article-results. Pre-registered single-trial analyses also yielded a statistically significant effect for the nouns but not the articles. Exploratory Bayesian single-trial analyses showed that the article-effect may be non-zero but is likely far smaller than originally reported and too small to observe without very large sample sizes. Our results do not support the view that readers routinely pre-activate the phonological form of predictable words. © 2018, Nieuwland et al.
Large-scale replication study reveals a limit on probabilistic prediction in language comprehension
Politzer-Ahles, Stephen; Heyselaar, Evelien; Segaert, Katrien; Darley, Emily; Kazanina, Nina; Von Grebmer Zu Wolfsthurn, Sarah; Bartolozzi, Federica; Kogan, Vita; Ito, Aine; Mézière, Diane; Barr, Dale J; Rousselet, Guillaume A; Ferguson, Heather J; Busch-Moreno, Simon; Fu, Xiao; Tuomainen, Jyrki; Kulakova, Eugenia; Husband, E Matthew; Donaldson, David I; Kohút, Zdenko; Rueschemeyer, Shirley-Ann; Huettig, Falk
2018-01-01
Do people routinely pre-activate the meaning and even the phonological form of upcoming words? The most acclaimed evidence for phonological prediction comes from a 2005 Nature Neuroscience publication by DeLong, Urbach and Kutas, who observed a graded modulation of electrical brain potentials (N400) to nouns and preceding articles by the probability that people use a word to continue the sentence fragment (‘cloze’). In our direct replication study spanning 9 laboratories (N=334), pre-registered replication-analyses and exploratory Bayes factor analyses successfully replicated the noun-results but, crucially, not the article-results. Pre-registered single-trial analyses also yielded a statistically significant effect for the nouns but not the articles. Exploratory Bayesian single-trial analyses showed that the article-effect may be non-zero but is likely far smaller than originally reported and too small to observe without very large sample sizes. Our results do not support the view that readers routinely pre-activate the phonological form of predictable words. PMID:29631695
Steigen, Anne Mari; Bergh, Daniel
2018-02-05
This article analyses the psychometric properties of the Social Provisions Scale 10-items version. The Social Provisions Scale was analysed by means of the polytomous Rasch model, applied to data on 93 young adults (16-30 years) out of school or work, participating in different nature-based services, due to mental or drug-related problems. The psychometric analysis concludes that the original scale has difficulties related to targeting and construct validity. In order to improve the psychometric properties, the scale was modified to include eight items measuring functional support. The modification was based on theoretical and statistical considerations. After modifications the scale showed not only satisfying psychometric properties, but it also clarified uncertainties regarding construct validity of the measure. However, further analysis on larger samples are required. Implications for Rehabilitation Social support is important for a variety of rehabilitation outcomes and for different patient groups in the rehabilitation context, including people with mental health or drug-related problems. Social Provisions Scale may be used as a screening tool to assess social support of participants in rehabilitation, and the scale may also be an important instrument in rehabilitation research. There might be issues measuring structural support using a 10-items version of the Social Provisions Scale but it seemed to work well as an 8-item scale measuring functional support.
Validation of decisional balance and self-efficacy measures for HPV vaccination in college women.
Lipschitz, Jessica M; Fernandez, Anne C; Larson, H Elsa; Blaney, Cerissa L; Meier, Kathy S; Redding, Colleen A; Prochaska, James O; Paiva, Andrea L
2013-01-01
Women younger than 25 years are at greatest risk for human papillomavirus (HPV) infection, including high-risk strains associated with 70% of cervical cancers. Effective model-based measures that can lead to intervention development to increase HPV vaccination rates are necessary. This study validated Transtheoretical Model measures of Decisional Balance and Self-Efficacy for seeking the HPV vaccine in a sample of female college students. Cross-sectional measurement development. Setting. Online survey of undergraduate college students. A total of 340 female students ages 18 to 26 years. Stage of Change, Decisional Balance, and Self-Efficacy. The sample was randomly split into halves for exploratory principal components analyses (PCAs), followed by confirmatory factor analyses (CFAs) to test measurement models. Multivariate analyses examined relationships between constructs. For Decisional Balance, PCA indicated two 4-item factors (Pros -α = .90; and Cons -α = .66). CFA supported a two-factor correlated model, χ(2)(19) = 39.33; p < .01; comparative fit index (CFI) = .97; and average absolute standardized residual statistic (AASR) = .03; with Pros α = .90 and Cons α = .67. For Self-Efficacy, PCA indicated one 6-item factor (α = .84). CFA supported this structure, χ(2)(9) = 50.87; p < .05; CFI = .94; AASR = .03; and α = .90. Multivariate analyses indicated significant cross-stage differences on Pros, Cons, and Self-Efficacy in expected directions. Findings support the internal and external validity of these measures and their use in Transtheoretical Model-tailored interventions. Stage-construct relationships suggest that reducing the Cons of vaccination may be more important for HPV than for behaviors with a true Maintenance stage.
Wilkinson, Michael
2014-03-01
Decisions about support for predictions of theories in light of data are made using statistical inference. The dominant approach in sport and exercise science is the Neyman-Pearson (N-P) significance-testing approach. When applied correctly it provides a reliable procedure for making dichotomous decisions for accepting or rejecting zero-effect null hypotheses with known and controlled long-run error rates. Type I and type II error rates must be specified in advance and the latter controlled by conducting an a priori sample size calculation. The N-P approach does not provide the probability of hypotheses or indicate the strength of support for hypotheses in light of data, yet many scientists believe it does. Outcomes of analyses allow conclusions only about the existence of non-zero effects, and provide no information about the likely size of true effects or their practical/clinical value. Bayesian inference can show how much support data provide for different hypotheses, and how personal convictions should be altered in light of data, but the approach is complicated by formulating probability distributions about prior subjective estimates of population effects. A pragmatic solution is magnitude-based inference, which allows scientists to estimate the true magnitude of population effects and how likely they are to exceed an effect magnitude of practical/clinical importance, thereby integrating elements of subjective Bayesian-style thinking. While this approach is gaining acceptance, progress might be hastened if scientists appreciate the shortcomings of traditional N-P null hypothesis significance testing.
Trends in study design and the statistical methods employed in a leading general medicine journal.
Gosho, M; Sato, Y; Nagashima, K; Takahashi, S
2018-02-01
Study design and statistical methods have become core components of medical research, and the methodology has become more multifaceted and complicated over time. The study of the comprehensive details and current trends of study design and statistical methods is required to support the future implementation of well-planned clinical studies providing information about evidence-based medicine. Our purpose was to illustrate study design and statistical methods employed in recent medical literature. This was an extension study of Sato et al. (N Engl J Med 2017; 376: 1086-1087), which reviewed 238 articles published in 2015 in the New England Journal of Medicine (NEJM) and briefly summarized the statistical methods employed in NEJM. Using the same database, we performed a new investigation of the detailed trends in study design and individual statistical methods that were not reported in the Sato study. Due to the CONSORT statement, prespecification and justification of sample size are obligatory in planning intervention studies. Although standard survival methods (eg Kaplan-Meier estimator and Cox regression model) were most frequently applied, the Gray test and Fine-Gray proportional hazard model for considering competing risks were sometimes used for a more valid statistical inference. With respect to handling missing data, model-based methods, which are valid for missing-at-random data, were more frequently used than single imputation methods. These methods are not recommended as a primary analysis, but they have been applied in many clinical trials. Group sequential design with interim analyses was one of the standard designs, and novel design, such as adaptive dose selection and sample size re-estimation, was sometimes employed in NEJM. Model-based approaches for handling missing data should replace single imputation methods for primary analysis in the light of the information found in some publications. Use of adaptive design with interim analyses is increasing after the presentation of the FDA guidance for adaptive design. © 2017 John Wiley & Sons Ltd.
Engineering evaluation of SSME dynamic data from engine tests and SSV flights
NASA Technical Reports Server (NTRS)
1986-01-01
An engineering evaluation of dynamic data from SSME hot firing tests and SSV flights is summarized. The basic objective of the study is to provide analyses of vibration, strain and dynamic pressure measurements in support of MSFC performance and reliability improvement programs. A brief description of the SSME test program is given and a typical test evaluation cycle reviewed. Data banks generated to characterize SSME component dynamic characteristics are described and statistical analyses performed on these data base measurements are discussed. Analytical models applied to define the dynamic behavior of SSME components (such as turbopump bearing elements and the flight accelerometer safety cut-off system) are also summarized. Appendices are included to illustrate some typical tasks performed under this study.
Statistical Data Analyses of Trace Chemical, Biochemical, and Physical Analytical Signatures
DOE Office of Scientific and Technical Information (OSTI.GOV)
Udey, Ruth Norma
Analytical and bioanalytical chemistry measurement results are most meaningful when interpreted using rigorous statistical treatments of the data. The same data set may provide many dimensions of information depending on the questions asked through the applied statistical methods. Three principal projects illustrated the wealth of information gained through the application of statistical data analyses to diverse problems.
Burr, Hermann; Hasselhorn, Hans Martin; Kersten, Norbert; Pohrt, Anne; Rugulies, Reiner
2017-09-01
Objectives Few epidemiological studies have examined whether associations of psychosocial working conditions with risk of poor health differ by age. Based on results from mostly cross-sectional studies, we test whether (i) psychosocial relational factors (social support) are more strongly associated with declining health of older than younger employees and (ii) psychosocial job factors (workpace, influence, possibilities for development) are more strongly associated with declining health of younger than older employees. Methods We extracted two cohorts from the Danish Work Environment Cohort Study (DWECS): the 2000-2005 and 2005-2010 cohorts. The participating 5281 employees with good self-rated health (SRH) at baseline were observed in 6585 5-year time windows. Using log-binomial regression analyses, we analysed whether psychosocial factors at work predicted 5-year deterioration of SRH. Effect modification by age was estimated by calculating relative excess risk due to interaction (RERI). Results High workpace among men, low influence at work as well as low social support from colleagues among women, and low possibilities for development and low social support from supervisors among both genders predicted 5-year decline in SRH. Of the 20 interaction analyses, only 1 was statistically significant and in the opposite direction of what was hypothesized (higher risk for declining SRH among middle-aged men with low possibilities for development compared to the young men with high possibilities for development). Conclusions Psychosocial working conditions predicted decline in SRH in this 5-year follow-up study. The model did not support our hypotheses about modifying effects by age.
Sanford, Stacy D; Beaumont, Jennifer L; Snyder, Mallory A; Reichek, Jennifer; Salsman, John M
2017-05-01
Minimal clinical trial participation among adolescents and young adults (AYAs) with cancer limits scientific progress and ultimately their clinical care and outcomes. These analyses examine the current state of AYA clinical research participation at a Midwestern comprehensive cancer center and affiliated pediatric hospital to advise program development and increase availability of trials and AYA participation. Enrollment is examined across all diagnoses, the entire AYA age spectrum (15-39), and both cancer therapeutic and supportive care protocols. his study was a retrospective review of electronic medical records via existing databases and registries for all AYAs. Data were collected for AYAs seen by an oncologist at the adult outpatient cancer center or at the pediatric hospital between the years 2010 and 2014. Descriptive statistics and logistic regression analyses were conducted to characterize this sample. In the pediatric setting, 42.3% of AYAs were enrolled in a study compared to 11.2% in the adult setting. Regression analyses in the pediatric setting revealed that AYAs with private insurance or Caucasian race were more likely to participate. Within the adult setting, ethnicity, race, insurance, and diagnosis were associated with study participation; 54.8% of study enrollments were for cancer therapeutic and 43.4% for supportive care studies. These results are comparable to previously published data and support the need for new local and national AYA initiatives to increase the availability of and enrollment in therapeutic clinical trials. The same is true for supportive care studies which play a crucial role in improving quality of life.
Vleeshouwers, Jolien; Knardahl, Stein; Christensen, Jan Olav
2016-01-01
Study Objectives: This prospective cohort study examined previously underexplored relations between psychological/social work factors and troubled sleep in order to provide practical information about specific, modifiable factors at work. Methods: A comprehensive evaluation of a range of psychological/social work factors was obtained by several designs; i.e., cross-sectional analyses at baseline and follow-up, prospective analyses with baseline predictors (T1), prospective analyses with average exposure across waves as predictor ([T1 + T2] / 2), and prospective analyses with change in exposure from baseline to follow-up as predictor. Participants consisted of a sample of Norwegian employees from a broad spectrum of occupations, who completed a questionnaire at two points in time, approximately two years apart. Cross-sectional analyses at T1 comprised 7,459 participants, cross-sectional analyses at T2 included 6,688 participants. Prospective analyses comprised a sample 5,070 of participants who responded at both T1 and T2. Univariable and multivariable ordinal logistic regressions were performed. Results: Thirteen psychological/social work factors and two aspects of troubled sleep, namely difficulties initiating sleep and disturbed sleep, were studied. Ordinal logistic regressions revealed statistically significant associations for all psychological and social work factors in at least one of the analyses. Psychological and social work factors predicted sleep problems in the short term as well as the long term. Conclusions: All work factors investigated showed statistically significant associations with both sleep items, however quantitative job demands, decision control, role conflict, and support from superior were the most robust predictors and may therefore be suitable targets of interventions aimed at improving employee sleep. Citation: Vleeshouwers J, Knardahl S, Christensen JO. Effects of psychological and social work factors on self-reported sleep disturbance and difficulties initiating sleep. SLEEP 2016;39(4):833–846. PMID:26446114
Sukkarieh-Haraty, Ola; Howard, Elizabeth
2015-01-01
The purpose of this study was to assess the relationship between diabetes self-care, diabetes-specific emotional distress, and social support and glycemic control (hemoglobin A1C levels: HbA1c) among a sample of Lebanese adults with type 2 diabetes. A descriptive correlational design was adapted with descriptive statistics and multiple logistic regressions for analyses. A convenience sample of 140 adults diagnosed with type 2 diabetes was recruited from 2 diabetes clinics in Greater Beirut. Participants were asked to complete 4 questionnaires in Arabic. Significant associations (P < .05) were found between following a general diet for more than 3.5 days per week and higher social support and HbA1c levels of 7% or more. Social support was positively associated with HbA1c levels such that participants with uncontrolled glycemic levels, as evidenced by higher values for HbA1c, received more support from their social network.
Nour-Eldein, Hebatallah
2016-01-01
With limited statistical knowledge of most physicians it is not uncommon to find statistical errors in research articles. To determine the statistical methods and to assess the statistical errors in family medicine (FM) research articles that were published between 2010 and 2014. This was a cross-sectional study. All 66 FM research articles that were published over 5 years by FM authors with affiliation to Suez Canal University were screened by the researcher between May and August 2015. Types and frequencies of statistical methods were reviewed in all 66 FM articles. All 60 articles with identified inferential statistics were examined for statistical errors and deficiencies. A comprehensive 58-item checklist based on statistical guidelines was used to evaluate the statistical quality of FM articles. Inferential methods were recorded in 62/66 (93.9%) of FM articles. Advanced analyses were used in 29/66 (43.9%). Contingency tables 38/66 (57.6%), regression (logistic, linear) 26/66 (39.4%), and t-test 17/66 (25.8%) were the most commonly used inferential tests. Within 60 FM articles with identified inferential statistics, no prior sample size 19/60 (31.7%), application of wrong statistical tests 17/60 (28.3%), incomplete documentation of statistics 59/60 (98.3%), reporting P value without test statistics 32/60 (53.3%), no reporting confidence interval with effect size measures 12/60 (20.0%), use of mean (standard deviation) to describe ordinal/nonnormal data 8/60 (13.3%), and errors related to interpretation were mainly for conclusions without support by the study data 5/60 (8.3%). Inferential statistics were used in the majority of FM articles. Data analysis and reporting statistics are areas for improvement in FM research articles.
Nour-Eldein, Hebatallah
2016-01-01
Background: With limited statistical knowledge of most physicians it is not uncommon to find statistical errors in research articles. Objectives: To determine the statistical methods and to assess the statistical errors in family medicine (FM) research articles that were published between 2010 and 2014. Methods: This was a cross-sectional study. All 66 FM research articles that were published over 5 years by FM authors with affiliation to Suez Canal University were screened by the researcher between May and August 2015. Types and frequencies of statistical methods were reviewed in all 66 FM articles. All 60 articles with identified inferential statistics were examined for statistical errors and deficiencies. A comprehensive 58-item checklist based on statistical guidelines was used to evaluate the statistical quality of FM articles. Results: Inferential methods were recorded in 62/66 (93.9%) of FM articles. Advanced analyses were used in 29/66 (43.9%). Contingency tables 38/66 (57.6%), regression (logistic, linear) 26/66 (39.4%), and t-test 17/66 (25.8%) were the most commonly used inferential tests. Within 60 FM articles with identified inferential statistics, no prior sample size 19/60 (31.7%), application of wrong statistical tests 17/60 (28.3%), incomplete documentation of statistics 59/60 (98.3%), reporting P value without test statistics 32/60 (53.3%), no reporting confidence interval with effect size measures 12/60 (20.0%), use of mean (standard deviation) to describe ordinal/nonnormal data 8/60 (13.3%), and errors related to interpretation were mainly for conclusions without support by the study data 5/60 (8.3%). Conclusion: Inferential statistics were used in the majority of FM articles. Data analysis and reporting statistics are areas for improvement in FM research articles. PMID:27453839
Caring for a child with cancer: a longitudinal perspective.
Svavarsdottir, Erla Kolbrun
2005-04-01
This paper reports a study to evaluate caregiving demands among mothers and fathers of children with cancer, parents' well-being, and how the parents perceive the health status of their child over a period of 18 months. Cancer among children has psychological impact on all family members. Most previous research has focused on distress, coping patterns and social support, and less is known about how parents are dealing with the illness experience over time. No study was found that evaluated caregiving on a daily basis, or the impact of the cancer on wellbeing and perceptions of health within families. Data were collected between 1999 and 2001. Parents of 26 Icelandic children under 18 years with cancer completed questionnaires about caregiving activities, general wellbeing and health perceptions. Descriptive statistics and Repeated Analyses of Variance were conducted at baseline, 12 and 18 months. The most time-consuming and difficult caregiving activities for both mothers and fathers were giving emotional support to the child with cancer, and to other children in the family. Mothers also found it difficult and time-consuming to manage behavioural problems and to structure and plan activities for the family. Fathers found it difficult to manage work and organize care for the child at the same time, and to give their partner emotional support. When evaluated over time, mothers' caregiving demands differed statistically significantly from fathers', and fathers' caregiving demands and health perceptions changed statistically significantly over the 18 months of the study. These findings underline the long-term impact of children's cancer on their families. Interventions focusing on emotional support, parents' wellbeing, and how families perceive the health of their child with cancer might benefit the family as a whole.
A systematic review of workplace ergonomic interventions with economic analyses.
Tompa, Emile; Dolinschi, Roman; de Oliveira, Claire; Amick, Benjamin C; Irvin, Emma
2010-06-01
This article reports on a systematic review of workplace ergonomic interventions with economic evaluations. The review sought to answer the question: "what is the credible evidence that incremental investment in ergonomic interventions is worth undertaking?" Past efforts to synthesize evidence from this literature have focused on effectiveness, whereas this study synthesizes evidence on the cost-effectiveness/financial merits of such interventions. Through a structured journal database search, 35 intervention studies were identified in nine industrial sectors. A qualitative synthesis approach, known as best evidence synthesis, was used rather than a quantitative approach because of the diversity of study designs and statistical analyses found across studies. Evidence on the financial merits of interventions was synthesized by industrial sector. In the manufacturing and warehousing sector strong evidence was found in support of the financial merits of ergonomic interventions from a firm perspective. In the administrative support and health care sectors moderate evidence was found, in the transportation sector limited evidence, and in remaining sectors insufficient evidence. Most intervention studies focus on effectiveness. Few consider their financial merits. Amongst the few that do, several had exemplary economic analyses, although more than half of the studies had low quality economic analyses. This may be due to the low priority given to economic analysis in this literature. Often only a small part of the overall evaluation of many studies focused on evaluating their cost-effectiveness.
Public insurance program impact on catastrophic health expenditure on acute myocardial infarction.
Martínez-García, M; Vargas-Barrón, J; Bañuelos-Téllez, F; González-Pacheco, H; Fresno, C; Hernández-Lemus, E; Martínez-Ríos, M A; Vallejo, M
2018-05-01
ST-segment elevation myocardial infarction (STEMI) has an important economic burden that poised the urgent need to evaluate its catastrophic medical expense. This study evaluates the first 5 years of the national health initiative called Popular Insurance (PI) at the National Institute of Cardiology in Mexico. Retrospective data analysis. STEMI patients with (n=317) and without (n=260) PI were selected. Analysed variables included socio-economical context, management care, cost evaluation and three outcomes (mortality, hospital readmission and therapeutic adherence). Descriptive statistical analyses, Kaplan-Meier survival and Support Vector Machine models were used accordingly. Treatment costs were higher for PI-covered individuals (P=0.022) and only 1.89% of them remained in debt, in contrast to 16.15% of those without PI. Statistically significant differences were found in relation to days in hospital wards (P<0.001), imaging studies (P<0.001) and surgical materials (P=0.04). Survival analysis (P=0.44) and therapeutic adherence (P=0.38) showed no differences. Hospital readmission was predicted with an 81.97% accuracy. The most important predictive variables included were stent type, number of days at the coronary care unit and hospital wards. The PI has proven to be a successful program where no differences were found in terms of health care and survival, whereas it provides timely financial support for families facing catastrophic health challenging events. Copyright © 2018 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.
Early Warning Signs of Suicide in Service Members Who Engage in Unauthorized Acts of Violence
2016-06-01
observable to military law enforcement personnel. Statistical analyses tested for differences in warning signs between cases of suicide, violence, or...indicators, (2) Behavioral Change indicators, (3) Social indicators, and (4) Occupational indicators. Statistical analyses were conducted to test for...6 Coding _________________________________________________________________ 7 Statistical
NASA Technical Reports Server (NTRS)
Raiman, Laura B.
1992-01-01
Total Quality Management (TQM) is a cooperative form of doing business that relies on the talents of everyone in an organization to continually improve quality and productivity, using teams and an assortment of statistical and measurement tools. The objective of the activities described in this paper was to implement effective improvement tools and techniques in order to build work processes which support good management and technical decisions and actions which are crucial to the success of the ACRV project. The objectives were met by applications in both the technical and management areas. The management applications involved initiating focused continuous improvement projects with widespread team membership. The technical applications involved applying proven statistical tools and techniques to the technical issues associated with the ACRV Project. Specific activities related to the objective included working with a support contractor team to improve support processes, examining processes involved in international activities, a series of tutorials presented to the New Initiatives Office and support contractors, a briefing to NIO managers, and work with the NIO Q+ Team. On the technical side, work included analyzing data from the large-scale W.A.T.E.R. test, landing mode trade analyses, and targeting probability calculations. The results of these efforts will help to develop a disciplined, ongoing process for producing fundamental decisions and actions that shape and guide the ACRV organization .
NASA Astrophysics Data System (ADS)
Raiman, Laura B.
1992-12-01
Total Quality Management (TQM) is a cooperative form of doing business that relies on the talents of everyone in an organization to continually improve quality and productivity, using teams and an assortment of statistical and measurement tools. The objective of the activities described in this paper was to implement effective improvement tools and techniques in order to build work processes which support good management and technical decisions and actions which are crucial to the success of the ACRV project. The objectives were met by applications in both the technical and management areas. The management applications involved initiating focused continuous improvement projects with widespread team membership. The technical applications involved applying proven statistical tools and techniques to the technical issues associated with the ACRV Project. Specific activities related to the objective included working with a support contractor team to improve support processes, examining processes involved in international activities, a series of tutorials presented to the New Initiatives Office and support contractors, a briefing to NIO managers, and work with the NIO Q+ Team. On the technical side, work included analyzing data from the large-scale W.A.T.E.R. test, landing mode trade analyses, and targeting probability calculations. The results of these efforts will help to develop a disciplined, ongoing process for producing fundamental decisions and actions that shape and guide the ACRV organization .
White-Williams, Connie; Grady, Kathleen L.; Myers, Susan; Naftel, David C.; Wang, Edward; Bourge, Robert; Rybarczyk, Bruce
2012-01-01
Background Despite the fact that social support has been found to be important to cardiovascular health, there is a paucity of information regarding the relationship between social support and outcomes long-term after heart transplantation (HT). Objectives Thus, the purposes of our retrospective analyses of a prospective, longitudinal study were to examine (1) the relationship between satisfaction with social support and post HT health-related quality of life (HRQOL) and survival, and (2) whether two types of social support (emotional and tangible) were predictors of survival and HRQOL. Methods Data were collected from 555 HT patients over a 5-year period (78% male, 88% white, mean age=53.8 years at time of transplant) at 4 U.S. medical centers using the following instruments: Social Support Index, QOL Index, HT Stressor Scale, Jalowiec Coping Scale, and medical records review. Statistical analyses included t-tests, correlations, Kaplan-Meier survival actuarials, and linear and multivariable regression. Results Patients were very satisfied with overall social support from 5 to 10 years after HT (0=very satisfied, 1=very dissatisfied) which was stable across time (p = 0.74). Satisfaction with emotional social support (p = 0.53) and tangible social support (p = 0.61) also remained stable over time. When stratified into low, medium and high levels of satisfaction, satisfaction with social support was not related to survival (p = 0.24). At 5 years, overall satisfaction with social support was a predictor of HRQOL ( r2=.59, p<.0001), and satisfaction with emotional social support was a predictor of HRQOL at 10 years post HT ( r2=.66, p<.0001). Conclusions Patients were very satisfied over time with emotional and tangible social support. While social support explained QOL outcomes, it did not predict survival. Knowledge of relationships among social support, stress, and outcomes may assist clinicians to address social support needs and resources long-term after HT. PMID:22580630
Fuochi, G; Foà, C
2018-03-01
Quality of life, coping strategies, social support and self-efficacy are important psychosocial variables strongly affecting the experience of acute myocardial infarction (AMI) in women. To gain a more in-depth understanding of how coping strategies, self-efficacy, quality of life and social support shape women's adjustment to AMI. Mixed methods study. Quantitative data were collected through a standardised questionnaire on coping strategies, self-efficacy, quality of life and social support. Qualitative data stemmed from 57 semistructured interviews conducted with post-AMI female patients on related topics. Quantitative data were analysed with unpaired two-sample t-tests on the means, comparing women who experienced AMI (N = 77) with a control group of women who did not have AMI (N = 173), and pairwise correlations on the AMI sample. Qualitative data were grouped into coding families and analysed through thematic content analysis. Qualitative and quantitative results were then integrated, for different age groups. Quantitative results indicated statistically significant differences between women who experienced AMI and the control group: the former showed lower self-perceived health, perceived social support and social support coping, but greater self-efficacy, use of acceptance, avoidance and religious coping. Pairwise correlations showed that avoidance coping strategy was negatively correlated with quality of life, while the opposite was true for problem-oriented coping, perceived social support and self-efficacy. Qualitative results extended and confirmed quantitative results, except for coping strategies: avoidance coping seemed more present than reported in the standardised measures. Mixed methods provide understanding of the importance of social support, self-efficacy and less avoidant coping strategies to women's adjustment to AMI. Women need support from health professionals with knowledge of these topics, to facilitate their adaptation to AMI. © 2017 Nordic College of Caring Science.
Kolarcik, Peter; Geckova, Andrea Madarasova; Reijneveld, Sijmen A; Van Dijk, Jitse P
2015-11-19
According to the EU-MIDIS report on discrimination, Roma are the most discriminated against group in Europe. Research suggests that experiencing discrimination may itself be detrimental to health. The aim of this paper is to investigate whether discrimination, hopelessness and social support mediate differences in self-rated health (SRH) between Roma and non-Roma adolescents. We conducted a cross-sectional study among Roma from separated and segregated settlements in the eastern part of Slovakia (N = 330; mean age = 14.50; interview) and non-Roma adolescents (N = 722; mean age = 14.86; questionnaire); only non-missing data were used for analyses (n = 759). The effect of perceived discrimination, mother and father social support, and hopelessness on SRH was analysed as crude and adjusted for ethnicity, age, gender, parental education and social desirability. Mediating effects were separately assessed using the Sobel test and structural equation modelling. Roma adolescents reported poorer SRH and more discrimination, mother and father social support, hopelessness and social desirability. Roma ethnicity (Odds ratio/95 %-Confidence interval 3.27/2.40-4.47), discrimination (2.66/1.82-3.88), hopelessness (1.35/1.20-1.51) and mother (0.92/0.88-0.97) and father social support (0.96/0.93 - 0.997) were statistically significant predictors of poor SRH. Perceived discrimination, social support and hopelessness mediated the ethnicity-health association, with adjustment for social support increasing its strength and the other two variables decreasing it. Perceived discrimination, social support and hopelessness mediate a part of the association between Roma ethnicity and poor SRH, with discrimination and hopelessness being risk factors and social support a protective factor.
Developing a workplace breast feeding support model for employed lactating mothers.
Yimyam, Susanha; Hanpa, Wasana
2014-06-01
Resuming work is often considered an obstacle for continued breast feeding. The objectives of this participatory action research study were to develop a breast feeding support model in the workplace and to compare breast feeding rates before and after implementation of the breast feeding support campaign. Twenty-four women participated before the implementation of the breast feeding support campaign, whereas 31 women participated after the campaign. Data were collected by interviewing employed women about their breast feeding practices within six months post partum. Additional data were collected through interviews with the workplace administrator and head of work sections as well as observation of the breast feeding support campaigns. Qualitative data were analysed using thematic analysis, whereas quantitative data were analysed using descriptive statistics and χ(2) test. The workplace breast feeding support model was developed based on the concept of Mother-Friendly Workplace Initiatives by the World Alliance for Breastfeeding Action (WABA) and the Thai government׳s promotion of a workplace breast feeding corner. Within this model, a committee for breast feeding support was created for working with the research team to develop breast feeding activities and media for breast feeding education and breast feeding support campaigns in the workplace. Breast feeding rates at six months after implementation of the breast feeding support campaign were significantly higher than rates before, both for exclusive breast feeding and any breast feeding at levels .004 and .033, respectively. These results suggest that breast feeding should be encouraged in every workplace depending on context. Individual advice and help for employed mothers should be provided from pregnancy through weaning in the postpartum period. Copyright © 2014 Elsevier Ltd. All rights reserved.
Using Network Analysis to Characterize Biogeographic Data in a Community Archive
NASA Astrophysics Data System (ADS)
Wellman, T. P.; Bristol, S.
2017-12-01
Informative measures are needed to evaluate and compare data from multiple providers in a community-driven data archive. This study explores insights from network theory and other descriptive and inferential statistics to examine data content and application across an assemblage of publically available biogeographic data sets. The data are archived in ScienceBase, a collaborative catalog of scientific data supported by the U.S Geological Survey to enhance scientific inquiry and acuity. In gaining understanding through this investigation and other scientific venues our goal is to improve scientific insight and data use across a spectrum of scientific applications. Network analysis is a tool to reveal patterns of non-trivial topological features in the data that do not exhibit complete regularity or randomness. In this work, network analyses are used to explore shared events and dependencies between measures of data content and application derived from metadata and catalog information and measures relevant to biogeographic study. Descriptive statistical tools are used to explore relations between network analysis properties, while inferential statistics are used to evaluate the degree of confidence in these assessments. Network analyses have been used successfully in related fields to examine social awareness of scientific issues, taxonomic structures of biological organisms, and ecosystem resilience to environmental change. Use of network analysis also shows promising potential to identify relationships in biogeographic data that inform programmatic goals and scientific interests.
The Center for Computational Biology: resources, achievements, and challenges
Dinov, Ivo D; Thompson, Paul M; Woods, Roger P; Van Horn, John D; Shattuck, David W; Parker, D Stott
2011-01-01
The Center for Computational Biology (CCB) is a multidisciplinary program where biomedical scientists, engineers, and clinicians work jointly to combine modern mathematical and computational techniques, to perform phenotypic and genotypic studies of biological structure, function, and physiology in health and disease. CCB has developed a computational framework built around the Manifold Atlas, an integrated biomedical computing environment that enables statistical inference on biological manifolds. These manifolds model biological structures, features, shapes, and flows, and support sophisticated morphometric and statistical analyses. The Manifold Atlas includes tools, workflows, and services for multimodal population-based modeling and analysis of biological manifolds. The broad spectrum of biomedical topics explored by CCB investigators include the study of normal and pathological brain development, maturation and aging, discovery of associations between neuroimaging and genetic biomarkers, and the modeling, analysis, and visualization of biological shape, form, and size. CCB supports a wide range of short-term and long-term collaborations with outside investigators, which drive the center's computational developments and focus the validation and dissemination of CCB resources to new areas and scientific domains. PMID:22081221
The Center for Computational Biology: resources, achievements, and challenges.
Toga, Arthur W; Dinov, Ivo D; Thompson, Paul M; Woods, Roger P; Van Horn, John D; Shattuck, David W; Parker, D Stott
2012-01-01
The Center for Computational Biology (CCB) is a multidisciplinary program where biomedical scientists, engineers, and clinicians work jointly to combine modern mathematical and computational techniques, to perform phenotypic and genotypic studies of biological structure, function, and physiology in health and disease. CCB has developed a computational framework built around the Manifold Atlas, an integrated biomedical computing environment that enables statistical inference on biological manifolds. These manifolds model biological structures, features, shapes, and flows, and support sophisticated morphometric and statistical analyses. The Manifold Atlas includes tools, workflows, and services for multimodal population-based modeling and analysis of biological manifolds. The broad spectrum of biomedical topics explored by CCB investigators include the study of normal and pathological brain development, maturation and aging, discovery of associations between neuroimaging and genetic biomarkers, and the modeling, analysis, and visualization of biological shape, form, and size. CCB supports a wide range of short-term and long-term collaborations with outside investigators, which drive the center's computational developments and focus the validation and dissemination of CCB resources to new areas and scientific domains.
ERIC Educational Resources Information Center
Leavy, Aisling; Hourigan, Mairead
2016-01-01
We argue that the development of statistical literacy is greatly supported by engaging students in carrying out statistical investigations. We describe the use of driving questions and interesting contexts to motivate two statistical investigations. The PPDAC cycle is use as an organizing framework to support the process statistical investigation.
Benefits of negative social exchanges for emotional closeness.
Fung, Helene H; Yeung, Dannii Y; Li, Kin-Kit; Lang, Frieder R
2009-09-01
Negative exchanges in social relationships have traditionally been studied as having negative consequences. This study explored whether they might have positive effects for relationship closeness. The sample included 351 adults, aged between 18 and 91 years, residing in Hong Kong, China. Closeness of social partners to the participants was measured by the Social Convoy Questionnaire, and the levels of negative exchanges and social support from each social partner were assessed. Multilevel analyses revealed that more negative exchanges were associated with a more positive change in closeness over a 2-year period, even after statistically controlling for social support and sociostructural characteristics of the participant and the social partner. Findings extended our knowledge on the positive effects of negative exchanges and their moderating conditions.
Zhang, Harrison G; Ying, Gui-Shuang
2018-02-09
The aim of this study is to evaluate the current practice of statistical analysis of eye data in clinical science papers published in British Journal of Ophthalmology ( BJO ) and to determine whether the practice of statistical analysis has improved in the past two decades. All clinical science papers (n=125) published in BJO in January-June 2017 were reviewed for their statistical analysis approaches for analysing primary ocular measure. We compared our findings to the results from a previous paper that reviewed BJO papers in 1995. Of 112 papers eligible for analysis, half of the studies analysed the data at an individual level because of the nature of observation, 16 (14%) studies analysed data from one eye only, 36 (32%) studies analysed data from both eyes at ocular level, one study (1%) analysed the overall summary of ocular finding per individual and three (3%) studies used the paired comparison. Among studies with data available from both eyes, 50 (89%) of 56 papers in 2017 did not analyse data from both eyes or ignored the intereye correlation, as compared with in 60 (90%) of 67 papers in 1995 (P=0.96). Among studies that analysed data from both eyes at an ocular level, 33 (92%) of 36 studies completely ignored the intereye correlation in 2017, as compared with in 16 (89%) of 18 studies in 1995 (P=0.40). A majority of studies did not analyse the data properly when data from both eyes were available. The practice of statistical analysis did not improve in the past two decades. Collaborative efforts should be made in the vision research community to improve the practice of statistical analysis for ocular data. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
NASA Astrophysics Data System (ADS)
Moore, Steven; Haviland, Don; Moore, William; Tran, Michael
2016-12-01
This article reports the findings of a 3-year study of a hybrid professional development program designed to prepare science and mathematics teachers to implement GIS in their classrooms. The study was conducted as part of the CoastLines Innovative Technology Experiences for Students and Teachers project funded by the National Science Foundation. Three cohorts of teachers participated in the program, with each participant receiving 40 h of synchronous online instruction and 80 h of in-person instruction and support over an 8-month period. Data from surveys of participants both before and after the program were analyzed using correlation, ordinary least squares, and ordered logit regression analyses. The analyses revealed increases in the self-reported frequency of GIS use and enhanced feelings of preparation, competence, community, and comfort with respect to using GIS for instruction. A composite index of all impact variables was positively influenced as well. The statistical analyses found a strong relationship between self-reported feelings of preparation and use of GIS. Some support was found for the idea that feelings of competence, community, and comfort were related to the teachers' sense of preparation. The findings suggest that a robust hybrid model of teacher professional development can prepare teachers to use GIS in their classrooms. More research is needed to understand how hybrid models influence the sociopsychological and other dimensions that support teachers' feelings of preparation to implement GIS.
Support, shape and number of replicate samples for tree foliage analysis.
Luyssaert, Sebastiaan; Mertens, Jan; Raitio, Hannu
2003-06-01
Many fundamental features of a sampling program are determined by the heterogeneity of the object under study and the settings for the error (alpha), the power (beta), the effect size (ES), the number of replicate samples, and sample support, which is a feature that is often overlooked. The number of replicates, alpha, beta, ES, and sample support are interconnected. The effect of the sample support and its shape on the required number of replicate samples was investigated by means of a resampling method. The method was applied to a simulated distribution of Cd in the crown of a Salix fragilis L. tree. Increasing the dimensions of the sample support results in a decrease in the variance of the element concentration under study. Analysis of the variance is often the foundation of statistical tests, therefore, valid statistical testing requires the use of a fixed sample support during the experiment. This requirement might be difficult to meet in time-series analyses and long-term monitoring programs. Sample supports have their largest dimension in the direction with the largest heterogeneity, i.e. the direction representing the crown height, and this will give more accurate results than supports with other shapes. Taking the relationships between the sample support and the variance of the element concentrations in tree crowns into account provides guidelines for sampling efficiency in terms of precision and costs. In terms of time, the optimal support to test whether the average Cd concentration of the crown exceeds a threshold value is 0.405 m3 (alpha = 0.05, beta = 0.20, ES = 1.0 mg kg(-1) dry mass). The average weight of this support is 23 g dry mass, and 11 replicate samples need to be taken. It should be noted that in this case the optimal support applies to Cd under conditions similar to those of the simulation, but not necessarily all the examinations for this tree species, element, and hypothesis test.
Lai, Betty S; Osborne, Melissa C; Piscitello, Jennifer; Self-Brown, Shannon; Kelley, Mary Lou
2018-01-01
Background : Children are a vulnerable population following a natural disaster, due to their age and dependence on adults. The primary presenting problem children report after disasters is posttraumatic stress symptoms (PTSS). Prior research suggests that PTSS is inversely related to social support, which is often disrupted after a disaster. Objective : This study examined the relationship between social support (from parents, teachers, and peers) and PTSS in children affected by Hurricane Katrina. The research contributes to the literature by examining the mechanisms that drive this relationship over time. Methods : In this study, 426 children were followed over four timepoints, beginning 3-7 months after Hurricane Katrina and concluding 25-27 months post-hurricane. Three path models analysed the relationship between social support (from parents, teachers, and peers, measured by the Social Support Scale for Children) and PTSS (measured by the UCLA PTSD Reaction Index). Covariates included child age, minority status, gender, perceived life threat, and actual life threat. Nonsignificant paths were trimmed from the final models. Global fit indices were examined to determine model fit. Results : In the parent and peer social support models, PTSS exhibited statistically significant effects on social support from one wave to the next. In the teacher model, this was only true between Waves 2 and 3. Social support showed a statistically significant effect on PTSS between Wave 2 and Wave 3 in the peer model (standardized estimate = -0.26, p < .0001). No paths from social support to PTSS were significant in the parent and teacher models. Conclusion : Findings support a social selection model in which PTSS undermine social support, particularly in the first two years post-disaster. If these findings are replicated, this suggests that, in cases of limited funding, PTSS should be prioritized, given their cascading effects on social support.
Using R-Project for Free Statistical Analysis in Extension Research
ERIC Educational Resources Information Center
Mangiafico, Salvatore S.
2013-01-01
One option for Extension professionals wishing to use free statistical software is to use online calculators, which are useful for common, simple analyses. A second option is to use a free computing environment capable of performing statistical analyses, like R-project. R-project is free, cross-platform, powerful, and respected, but may be…
Influence of family environment on language outcomes in children with myelomeningocele.
Vachha, B; Adams, R
2005-09-01
Previously, our studies demonstrated language differences impacting academic performance among children with myelomeningocele and shunted hydrocephalus (MMSH). This follow-up study considers the environmental facilitators within families (achievement orientation, intellectual-cultural orientation, active recreational orientation, independence) among a cohort of children with MMSH and their relationship to language performance. Fifty-eight monolingual, English-speaking children (36 females; mean age: 10.1 years; age range: 7-16 years) with MMSH were evaluated. Exclusionary criteria were prior shunt infection; seizure or shunt malfunction within the previous 3 months; uncorrected visual or auditory impairments; prior diagnoses of mental retardation or attention deficit disorder. The Comprehensive Assessment of Spoken Language (CASL) and the Wechsler Abbreviated Scale of Intelligence (WASI) were administered individually to all participants. The CASL Measures four subsystems: lexical, syntactic, supralinguistic and pragmatic. Parents completed the Family Environment Scale (FES) questionnaire and provided background demographic information. Spearman correlation analyses and partial correlation analyses were performed. Mean intelligence scores for the MMSH group: full scale IQ 92.2 (SD = 11.9). The CASL revealed statistically significant difficulty for supralinguistic and pragmatic (or social) language tasks. FES scores fell within the average range for the group. Spearman correlation and partial correlation analyses revealed statistically significant positive relationships for the FES 'intellectual-cultural orientation' variable and performance within the four language subsystems. Socio-economic status (SES) characteristics were analyzed and did not discriminate language performance when the intellectual-cultural orientation factor was taken into account. The role of family facilitators on language skills in children with MMSH has not previously been described. The relationship between language performance and the families' value on intellectual/cultural activities seems both statistically and intuitively sound. Focused interest in the integration of family values and practices should assist developmental specialists in supporting families and children within their most natural environment.
Mason, W Alex; Fleming, Charles B; Gross, Thomas J; Thompson, Ronald W; Parra, Gilbert R; Haggerty, Kevin P; Snyder, James J
2016-12-01
This randomized controlled trial tested a widely used general parent training program, Common Sense Parenting (CSP), with low-income 8th graders and their families to support a positive transition to high school. The program was tested in its original 6-session format and in a modified format (CSP-Plus), which added 2 sessions that included adolescents. Over 2 annual cohorts, 321 families were enrolled and randomly assigned to either the CSP, CSP-Plus, or minimal-contact control condition. Pretest, posttest, 1-year follow-up, and 2-year follow-up survey data on parenting as well as youth school bonding, social skills, and problem behaviors were collected from parents and youth (94% retention). Extending prior examinations of posttest outcomes, intent-to-treat regression analyses tested for intervention effects at the 2 follow-up assessments, and growth curve analyses examined experimental condition differences in yearly change across time. Separate exploratory tests of moderation by youth gender, youth conduct problems, and family economic hardship also were conducted. Out of 52 regression models predicting 1- and 2-year follow-up outcomes, only 2 out of 104 possible intervention effects were statistically significant. No statistically significant intervention effects were found in the growth curve analyses. Tests of moderation also showed few statistically significant effects. Because CSP already is in widespread use, findings have direct implications for practice. Specifically, findings suggest that the program may not be efficacious with parents of adolescents in a selective prevention context and may reveal the limits of brief, general parent training for achieving outcomes with parents of adolescents. (PsycINFO Database Record (c) 2016 APA, all rights reserved).
NASA Astrophysics Data System (ADS)
Ridgley, James Alexander, Jr.
This dissertation is an exploratory quantitative analysis of various independent variables to determine their effect on the professional longevity (years of service) of high school science teachers in the state of Florida for the academic years 2011-2012 to 2013-2014. Data are collected from the Florida Department of Education, National Center for Education Statistics, and the National Assessment of Educational Progress databases. The following research hypotheses are examined: H1 - There are statistically significant differences in Level 1 (teacher variables) that influence the professional longevity of a high school science teacher in Florida. H2 - There are statistically significant differences in Level 2 (school variables) that influence the professional longevity of a high school science teacher in Florida. H3 - There are statistically significant differences in Level 3 (district variables) that influence the professional longevity of a high school science teacher in Florida. H4 - When tested in a hierarchical multiple regression, there are statistically significant differences in Level 1, Level 2, or Level 3 that influence the professional longevity of a high school science teacher in Florida. The professional longevity of a Floridian high school science teacher is the dependent variable. The independent variables are: (Level 1) a teacher's sex, age, ethnicity, earned degree, salary, number of schools taught in, migration count, and various years of service in different areas of education; (Level 2) a school's geographic location, residential population density, average class size, charter status, and SES; and (Level 3) a school district's average SES and average spending per pupil. Statistical analyses of exploratory MLRs and a HMR are used to support the research hypotheses. The final results of the HMR analysis show a teacher's age, salary, earned degree (unknown, associate, and doctorate), and ethnicity (Hispanic and Native Hawaiian/Pacific Islander); a school's charter status; and a school district's average SES are all significant predictors of a Florida high school science teacher's professional longevity. Although statistically significant in the initial exploratory MLR analyses, a teacher's ethnicity (Asian and Black), a school's geographic location (city and rural), and a school's SES are not statistically significant in the final HMR model.
Statistical technique for analysing functional connectivity of multiple spike trains.
Masud, Mohammad Shahed; Borisyuk, Roman
2011-03-15
A new statistical technique, the Cox method, used for analysing functional connectivity of simultaneously recorded multiple spike trains is presented. This method is based on the theory of modulated renewal processes and it estimates a vector of influence strengths from multiple spike trains (called reference trains) to the selected (target) spike train. Selecting another target spike train and repeating the calculation of the influence strengths from the reference spike trains enables researchers to find all functional connections among multiple spike trains. In order to study functional connectivity an "influence function" is identified. This function recognises the specificity of neuronal interactions and reflects the dynamics of postsynaptic potential. In comparison to existing techniques, the Cox method has the following advantages: it does not use bins (binless method); it is applicable to cases where the sample size is small; it is sufficiently sensitive such that it estimates weak influences; it supports the simultaneous analysis of multiple influences; it is able to identify a correct connectivity scheme in difficult cases of "common source" or "indirect" connectivity. The Cox method has been thoroughly tested using multiple sets of data generated by the neural network model of the leaky integrate and fire neurons with a prescribed architecture of connections. The results suggest that this method is highly successful for analysing functional connectivity of simultaneously recorded multiple spike trains. Copyright © 2011 Elsevier B.V. All rights reserved.
Los Alamos Climatology 2016 Update
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bruggeman, David Alan
The Los Alamos National Laboratory (LANL or the Laboratory) operates a meteorology monitoring network to support LANL emergency response, engineering designs, environmental compliance, environmental assessments, safety evaluations, weather forecasting, environmental monitoring, research programs, and environmental restoration. Weather data has been collected in Los Alamos since 1910. Bowen (1990) provided climate statistics (temperature and precipitation) for the 1961– 1990 averaging period, and included other analyses (e.g., wind and relative humidity) based on the available station locations and time periods. This report provides an update to the 1990 publication Los Alamos Climatology (Bowen 1990).
Content-based VLE designs improve learning efficiency in constructivist statistics education.
Wessa, Patrick; De Rycker, Antoon; Holliday, Ian Edward
2011-01-01
We introduced a series of computer-supported workshops in our undergraduate statistics courses, in the hope that it would help students to gain a deeper understanding of statistical concepts. This raised questions about the appropriate design of the Virtual Learning Environment (VLE) in which such an approach had to be implemented. Therefore, we investigated two competing software design models for VLEs. In the first system, all learning features were a function of the classical VLE. The second system was designed from the perspective that learning features should be a function of the course's core content (statistical analyses), which required us to develop a specific-purpose Statistical Learning Environment (SLE) based on Reproducible Computing and newly developed Peer Review (PR) technology. The main research question is whether the second VLE design improved learning efficiency as compared to the standard type of VLE design that is commonly used in education. As a secondary objective we provide empirical evidence about the usefulness of PR as a constructivist learning activity which supports non-rote learning. Finally, this paper illustrates that it is possible to introduce a constructivist learning approach in large student populations, based on adequately designed educational technology, without subsuming educational content to technological convenience. Both VLE systems were tested within a two-year quasi-experiment based on a Reliable Nonequivalent Group Design. This approach allowed us to draw valid conclusions about the treatment effect of the changed VLE design, even though the systems were implemented in successive years. The methodological aspects about the experiment's internal validity are explained extensively. The effect of the design change is shown to have substantially increased the efficiency of constructivist, computer-assisted learning activities for all cohorts of the student population under investigation. The findings demonstrate that a content-based design outperforms the traditional VLE-based design.
NASA Astrophysics Data System (ADS)
Nguyen, A.; Mueller, C.; Brooks, A. N.; Kislik, E. A.; Baney, O. N.; Ramirez, C.; Schmidt, C.; Torres-Perez, J. L.
2014-12-01
The Sierra Nevada is experiencing changes in hydrologic regimes, such as decreases in snowmelt and peak runoff, which affect forest health and the availability of water resources. Currently, the USDA Forest Service Region 5 is undergoing Forest Plan revisions to include climate change impacts into mitigation and adaptation strategies. However, there are few processes in place to conduct quantitative assessments of forest conditions in relation to mountain hydrology, while easily and effectively delivering that information to forest managers. To assist the USDA Forest Service, this study is the final phase of a three-term project to create a Decision Support System (DSS) to allow ease of access to historical and forecasted hydrologic, climatic, and terrestrial conditions for the entire Sierra Nevada. This data is featured within three components of the DSS: the Mapping Viewer, Statistical Analysis Portal, and Geospatial Data Gateway. Utilizing ArcGIS Online, the Sierra DSS Mapping Viewer enables users to visually analyze and locate areas of interest. Once the areas of interest are targeted, the Statistical Analysis Portal provides subbasin level statistics for each variable over time by utilizing a recently developed web-based data analysis and visualization tool called Plotly. This tool allows users to generate graphs and conduct statistical analyses for the Sierra Nevada without the need to download the dataset of interest. For more comprehensive analysis, users are also able to download datasets via the Geospatial Data Gateway. The third phase of this project focused on Python-based data processing, the adaptation of the multiple capabilities of ArcGIS Online and Plotly, and the integration of the three Sierra DSS components within a website designed specifically for the USDA Forest Service.
Hoven, Hanno; Siegrist, Johannes
2013-01-01
Social inequalities in health persist in modern societies. The contribution of adverse work and employment conditions towards their explanation is analysed by two approaches, mediation and moderation. Yet the relative significance of each approach remains unclear in respective research. We set out to study this question by conducting a systematic literature review. We included all original papers based on prospective observational studies of employed cohorts that were published between January 1980 and October 2012 meeting our search criteria, by using major databases and by observing established quality criteria. 26 reports were included after quality assessment. 17 studies examined the mediation hypothesis and nine studies tested the moderation hypothesis. Moderate support was found for the mediation hypothesis where OR or HR of health according to socioeconomic position (SEP) were reduced in a majority of analyses after introducing work characteristics in multivariate models. Evidence in favour of the moderation hypothesis was found in some studies, demonstrating stronger effects of adverse work on health among people with low SEP. Despite some support in favour of the two hypotheses future research should aim at reducing the heterogeneity in defining and measuring core variables and at applying advanced statistical analyses. Policy recommendations would benefit from a higher degree of consistency of respective research evidence. PMID:23739492
Anderson, Matthew J; Ialeggio, Donna M
2014-01-01
The present study sought to explore the possibility that lateral behaviour in captive Caribbean flamingos (Phoenicopterus ruber) housed at the Philadelphia Zoo (Philadelphia, PA) could be used to predict a variety of physiological measures of health obtained via complete blood counts (CBC) and plasma biochemistry analyses that were performed as part of the flock's annual physical examination. Consistent with previous research, evidence of rightward lateral neck-resting preferences were obtained, no evidence was found for the existence of leg stance preferences, and neck-resting and leg stance preferences were shown to be unrelated. Both lateral neck-resting preferences and lateral support leg preference were shown to be related to a variety of measures from the CBC and plasma biochemistry analyses. While several general trends emerged in regards to the CBC variables, the relationships between the lateral behaviours and those variables generated via plasma biochemistry analyses proved to be fewer and somewhat less consistent. Birds with rightward neck-resting preferences and birds with leftward support leg preferences generally appeared to be healthier and less stressed according to the CBC measures; however, the validity of lateral leg stance preference as a predictor of health and wellbeing is questionable given the lack of statistically significant leg stance preferences.
Hoven, Hanno; Siegrist, Johannes
2013-09-01
Social inequalities in health persist in modern societies. The contribution of adverse work and employment conditions towards their explanation is analysed by two approaches, mediation and moderation. Yet the relative significance of each approach remains unclear in respective research. We set out to study this question by conducting a systematic literature review. We included all original papers based on prospective observational studies of employed cohorts that were published between January 1980 and October 2012 meeting our search criteria, by using major databases and by observing established quality criteria. 26 reports were included after quality assessment. 17 studies examined the mediation hypothesis and nine studies tested the moderation hypothesis. Moderate support was found for the mediation hypothesis where OR or HR of health according to socioeconomic position (SEP) were reduced in a majority of analyses after introducing work characteristics in multivariate models. Evidence in favour of the moderation hypothesis was found in some studies, demonstrating stronger effects of adverse work on health among people with low SEP. Despite some support in favour of the two hypotheses future research should aim at reducing the heterogeneity in defining and measuring core variables and at applying advanced statistical analyses. Policy recommendations would benefit from a higher degree of consistency of respective research evidence.
The Problem of Auto-Correlation in Parasitology
Pollitt, Laura C.; Reece, Sarah E.; Mideo, Nicole; Nussey, Daniel H.; Colegrave, Nick
2012-01-01
Explaining the contribution of host and pathogen factors in driving infection dynamics is a major ambition in parasitology. There is increasing recognition that analyses based on single summary measures of an infection (e.g., peak parasitaemia) do not adequately capture infection dynamics and so, the appropriate use of statistical techniques to analyse dynamics is necessary to understand infections and, ultimately, control parasites. However, the complexities of within-host environments mean that tracking and analysing pathogen dynamics within infections and among hosts poses considerable statistical challenges. Simple statistical models make assumptions that will rarely be satisfied in data collected on host and parasite parameters. In particular, model residuals (unexplained variance in the data) should not be correlated in time or space. Here we demonstrate how failure to account for such correlations can result in incorrect biological inference from statistical analysis. We then show how mixed effects models can be used as a powerful tool to analyse such repeated measures data in the hope that this will encourage better statistical practices in parasitology. PMID:22511865
CyTOF workflow: differential discovery in high-throughput high-dimensional cytometry datasets
Nowicka, Malgorzata; Krieg, Carsten; Weber, Lukas M.; Hartmann, Felix J.; Guglietta, Silvia; Becher, Burkhard; Levesque, Mitchell P.; Robinson, Mark D.
2017-01-01
High dimensional mass and flow cytometry (HDCyto) experiments have become a method of choice for high throughput interrogation and characterization of cell populations.Here, we present an R-based pipeline for differential analyses of HDCyto data, largely based on Bioconductor packages. We computationally define cell populations using FlowSOM clustering, and facilitate an optional but reproducible strategy for manual merging of algorithm-generated clusters. Our workflow offers different analysis paths, including association of cell type abundance with a phenotype or changes in signaling markers within specific subpopulations, or differential analyses of aggregated signals. Importantly, the differential analyses we show are based on regression frameworks where the HDCyto data is the response; thus, we are able to model arbitrary experimental designs, such as those with batch effects, paired designs and so on. In particular, we apply generalized linear mixed models to analyses of cell population abundance or cell-population-specific analyses of signaling markers, allowing overdispersion in cell count or aggregated signals across samples to be appropriately modeled. To support the formal statistical analyses, we encourage exploratory data analysis at every step, including quality control (e.g. multi-dimensional scaling plots), reporting of clustering results (dimensionality reduction, heatmaps with dendrograms) and differential analyses (e.g. plots of aggregated signals). PMID:28663787
Sabes-Figuera, Ramon; McCrone, Paul; Kendricks, Antony
2013-04-01
Economic evaluation analyses can be enhanced by employing regression methods, allowing for the identification of important sub-groups and to adjust for imperfect randomisation in clinical trials or to analyse non-randomised data. To explore the benefits of combining regression techniques and the standard Bayesian approach to refine cost-effectiveness analyses using data from randomised clinical trials. Data from a randomised trial of anti-depressant treatment were analysed and a regression model was used to explore the factors that have an impact on the net benefit (NB) statistic with the aim of using these findings to adjust the cost-effectiveness acceptability curves. Exploratory sub-samples' analyses were carried out to explore possible differences in cost-effectiveness. Results The analysis found that having suffered a previous similar depression is strongly correlated with a lower NB, independent of the outcome measure or follow-up point. In patients with previous similar depression, adding an selective serotonin reuptake inhibitors (SSRI) to supportive care for mild-to-moderate depression is probably cost-effective at the level used by the English National Institute for Health and Clinical Excellence to make recommendations. This analysis highlights the need for incorporation of econometric methods into cost-effectiveness analyses using the NB approach.
Examining the breastfeeding support resources of the public health nursing services in Ireland.
Mulcahy, Helen; Phelan, Agnes; Corcoran, Paul; Leahy-Warren, Patricia
2012-04-01
The aim of the study was to review breastfeeding support provided by Public Health Nurses in Ireland. The objectives were to identify the availability of appropriate guiding policies, educational preparation, attitude of Public Health Nurses and the availability and use of other supportive services. Breastfeeding rates in Ireland are among the lowest in Europe. The main source of formal support for breastfeeding mothers in the community in Ireland is from Public Health Nurses who can make referral to other non-statutory resources. The nature of this support is determined by policies guiding clinical practice and education that increases breastfeeding confidence and competence of all personnel. Consequently, an assessment of breastfeeding resources requires an analysis of all these variables. A large quantitative, cross-sectional study was conducted, involving Public Health Nurses and mothers. This paper represents the results from the perspective of Public Health Nurses. Directors of Public Health Nursing (n = 24) and Public Health Nurses (n = 204) completed self-report questionnaires by mail and online. Data were analysed using the Statistical Package for Social Sciences and reported using descriptive and inferential statistics. Public Health Nurses are well educated to support breastfeeding and have a positive attitude and a high degree of self-assessed confidence and competence. A wide variety of non-statutory support exists for breastfeeding but is not always used to their full potential. Standardising educational requirements for Public Health Nurses in supporting breastfeeding is an area that requires attention. Ultimately, service delivery in relation to supporting breastfeeding mothers would benefit from being more timely and responsive. Awareness of support resources is necessary for Public Health Nurses to make appropriate referrals for breastfeeding mothers. Furthermore, Directors of Public Health Nursing need to encourage the breastfeeding supportive role of Public Health Nurses and facilitate continuing professional development. © 2011 Blackwell Publishing Ltd.
Fuzzy support vector machines for adaptive Morse code recognition.
Yang, Cheng-Hong; Jin, Li-Cheng; Chuang, Li-Yeh
2006-11-01
Morse code is now being harnessed for use in rehabilitation applications of augmentative-alternative communication and assistive technology, facilitating mobility, environmental control and adapted worksite access. In this paper, Morse code is selected as a communication adaptive device for persons who suffer from muscle atrophy, cerebral palsy or other severe handicaps. A stable typing rate is strictly required for Morse code to be effective as a communication tool. Therefore, an adaptive automatic recognition method with a high recognition rate is needed. The proposed system uses both fuzzy support vector machines and the variable-degree variable-step-size least-mean-square algorithm to achieve these objectives. We apply fuzzy memberships to each point, and provide different contributions to the decision learning function for support vector machines. Statistical analyses demonstrated that the proposed method elicited a higher recognition rate than other algorithms in the literature.
The RCP Information Laboratory (iLab): breaking the cycle of poor data quality.
Croft, Giles P; Williams, John G
2005-01-01
A review of data quality in the NHS by the Audit Commission cited a lack of clinician involvement in the validation and use of centrally held activity data as one of the key issues to resolve. The perception that hospital episode statistics cannot support the needs of the individual clinician results in mistrust and disinterest. This in turn leads to under-development of such data from a clinical perspective, and the cycle continues. The RCP Information Laboratory (iLab) aims to address this problem by accessing, analysing and presenting information from these central repositories concerning the activity of visiting individual consultant physicians. With support from iLab staff--an information analyst and a clinician--local data quality issues are highlighted and local solutions sought. The information obtained can be used as an objective measure of activity to support the processes of appraisal and revalidation.
Zhang, Zhefeng; Xian, Jiahui; Zhang, Chunyong; Fu, Degang
2017-09-01
This study investigated the degradation performance and mechanism of creatinine (a urine metabolite) with boron-doped diamond (BDD) anodes. Experiments were performed using a synthetic creatinine solution containing two supporting electrolytes (NaCl and Na 2 SO 4 ). A three-level central composite design was adopted to optimize the degradation process, a mathematical model was thus constructed and used to explore the optimum operating conditions. A maximum mineralization percentage of 80% following with full creatinine removal had been achieved within 120 min of electrolysis, confirming the strong oxidation capability of BDD anodes. Moreover, the results obtained suggested that supporting electrolyte concentration should be listed as one of the most important parameters in BDD technology. Lastly, based on the results from quantum chemistry calculations and LC/MS analyses, two different reaction pathways which governed the electrocatalytic oxidation of creatinine irrespective of the supporting electrolytes were identified. Copyright © 2017 Elsevier Ltd. All rights reserved.
Social support network and quality of life in multiple sclerosis patients.
Costa, David Castro; Sá, Maria José; Calheiros, José Manuel
2017-05-01
To analyse the relationship between the social support network (SSN) and health related quality of life (HRQOL) in multiple sclerosis (MS) patients. The sample comprised 150 consecutive MS patients attending our MS clinic. To assess the socio-demographic data, a specifically designed questionnaire was applied. The HRQOL dimensions were measured with the Short-Form Health Survey Questionnaire-SF36 and the SSN with the Medical Outcomes Study Social Support Survey. Spearman's correlation was used to compare the magnitude of the relationship between the SSN and HRQOL. The mean patient age was 41.7 years (± 10.4; range: 18-70 yr); the mean Expanded Disability Status Score was 2.5 (±2.4; range: 0-9). There was a statistically significant correlation between the structure of the SSN and the HRQOL. The composition of the SSN, social group membership and participation in voluntary work have an important role in the HRQOL of patients with MS.
Diffusion of innovations theory applied to global tobacco control treaty ratification.
Valente, Thomas W; Dyal, Stephanie R; Chu, Kar-Hai; Wipfli, Heather; Fujimoto, Kayo
2015-11-01
This study applies diffusion of innovations theory to understand network influences on country ratification of an international health treaty, the Framework Convention for Tobacco Control (FCTC). From 2003 to 2014 approximately 90% of United Nations member countries ratified the FCTC. We hypothesized that communication between tobacco control advocates on GLOBALink, a 7000-member online communication forum in existence from 1992 to 2012, would be associated with the timing of treaty ratification. We further hypothesized dynamic network influences such that external influence decreased over time, internal influence increased over time, and the role of opinion leader countries varied over time. In addition we develop two concepts: Susceptibility and influence that uncover the micro-level dynamics of network influence. Statistical analyses lend support to the influence of co-subscriptions on GLOBALink providing a conduit for inter-country influences on treaty ratification and some support for the dynamic hypotheses. Analyses of susceptibility and infection indicated particularly influential countries. These results have implications for the study of policy diffusion as well as dynamic models of behavior change. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.
Gitlin, Laura N.; Parisi, Jeanine; Huang, Jin; Winter, Laraine; Roth, David L.
2016-01-01
Purpose of study: Examine psychometric properties of Lawton’s Valuation of Life (VOL) scale, a measure of an older adults’ assessment of the perceived value of their lives; and whether ratings differ by race (White, Black/African American) and sex. Design and Methods: The 13-item VOL scale was administered at baseline in 2 separate randomized trials (Advancing Better Living for Elders, ABLE; Get Busy Get Better, GBGB) for a total of 527 older adults. Principal component analyses were applied to a subset of ABLE data (subsample 1) and confirmatory factor analyses were conducted on remaining data (subsample 2 and GBGB). Once the factor structure was identified and confirmed, 2 subscales were created, corresponding to optimism and engagement. Convergent validity of total and subscale scores were examined using measures of depressive symptoms, social support, control-oriented strategies, mastery, and behavioral activation. For discriminant validity, indices of health status, physical function, financial strain, cognitive status, and number of falls were examined. Results: Trial samples (ABLE vs. GBGB) differed by age, race, marital status, education, and employment. Principal component analysis on ABLE subsample 1 (n = 156) yielded two factors subsequently confirmed in confirmatory factor analyses on ABLE subsample 2 (n = 163) and GBGB sample (N = 208) separately. Adequate fit was found for the 2-factor model. Correlational analyses supported strong convergent and discriminant validity. Some statistically significant race and sex differences in subscale scores were found. Implications: VOL measures subjective appraisals of perceived value of life. Consisting of two interrelated subscales, it offers an efficient approach to ascertain personal attributions. PMID:26874189
Keohane, Denis; Schwartz, Jeffrey; Gundapaneni, Balarama; Stewart, Michelle; Amass, Leslie
2017-03-01
Tafamidis, a non-NSAID highly specific transthyretin stabilizer, delayed neurologic disease progression as measured by Neuropathy Impairment Score-Lower Limbs (NIS-LL) in an 18-month, double-blind, placebo-controlled randomized trial in 128 patients with early-stage transthyretin V30M familial amyloid polyneuropathy (ATTRV30M-FAP). The current post hoc analyses aimed to further evaluate the effects of tafamidis in delaying ATTRV30M-FAP progression in this trial. Pre-specified, repeated-measures analysis of change from baseline in NIS-LL in this trial (ClinicalTrials.gov NCT00409175) was repeated with addition of baseline as covariate and multiple imputation analysis for missing data by treatment group. Change in NIS-LL plus three small-fiber nerve tests (NIS-LL + Σ3) and NIS-LL plus seven nerve tests (NIS-LL + Σ7) were assessed without baseline as covariate. Treatment outcomes over the NIS-LL, Σ3, Σ7, modified body mass index and Norfolk Quality of Life-Diabetic Neuropathy Total Quality of Life Score were also examined using multivariate analysis techniques. Neuropathy progression based on NIS-LL change from baseline to Month 18 remained significantly reduced for tafamidis versus placebo in the baseline-adjusted and multiple imputation analyses. NIS-LL + Σ3 and NIS-LL + Σ7 captured significant treatment group differences. Multivariate analyses provided strong statistical evidence for a superior tafamidis treatment effect. These supportive analyses confirm that tafamidis delays neurologic progression in early-stage ATTRV30M-FAP. NCT00409175.
Koch-Gallenkamp, Lena; Bertram, Heike; Eberle, Andrea; Holleczek, Bernd; Schmid-Höpfner, Sieglinde; Waldmann, Annika; Zeissig, Sylke R; Brenner, Hermann; Arndt, Volker
2016-12-01
Fear of recurrence (FoR) is among the most important concerns for cancer survivors. Studies on potentially influencing variables, like time since diagnosis, cancer type, and sex, have yielded heterogeneous results. Also social support has rarely been examined as an influencing factor. This study aims to increase knowledge on these factors. Analyses are based on cross-sectional data of long-term survivors of breast, colorectal, and prostate cancer (5-16 years postdiagnosis), recruited by 6 German population-based cancer registries. Six thousand fifty-seven women and men were included in the analyses. FoR was assessed using the short form of the Fear of Progression Questionnaire (FoP-Q-SF). The associations of cancer type, age, sex, time since diagnosis, and social support with moderate/high FoR were identified via multiple logistic regression analyses. The majority of long-term cancer survivors reported experiencing FoR, mostly in low intensity. Female survivors, survivors ≤54 or 55-59 years of age, 5 to 7 years postdiagnosis, with a lower education, with recurrence/metastases, or being socially isolated were at greater risk to experience moderate/high FoR. Cancer type and stage at diagnosis did not reach statistical significance. Our results indicate a potential vulnerability for women to experience FoR in moderate/high severity. Also younger and socially isolated survivors were at greater risk to suffer from moderate/high levels of FoR and should thus be monitored for high levels of FoR and be offered the support needed to manage their fears. (PsycINFO Database Record (c) 2016 APA, all rights reserved).
Streicher, Jeffrey W; Schulte, James A; Wiens, John J
2016-01-01
Targeted sequence capture is becoming a widespread tool for generating large phylogenomic data sets to address difficult phylogenetic problems. However, this methodology often generates data sets in which increasing the number of taxa and loci increases amounts of missing data. Thus, a fundamental (but still unresolved) question is whether sampling should be designed to maximize sampling of taxa or genes, or to minimize the inclusion of missing data cells. Here, we explore this question for an ancient, rapid radiation of lizards, the pleurodont iguanians. Pleurodonts include many well-known clades (e.g., anoles, basilisks, iguanas, and spiny lizards) but relationships among families have proven difficult to resolve strongly and consistently using traditional sequencing approaches. We generated up to 4921 ultraconserved elements with sampling strategies including 16, 29, and 44 taxa, from 1179 to approximately 2.4 million characters per matrix and approximately 30% to 60% total missing data. We then compared mean branch support for interfamilial relationships under these 15 different sampling strategies for both concatenated (maximum likelihood) and species tree (NJst) approaches (after showing that mean branch support appears to be related to accuracy). We found that both approaches had the highest support when including loci with up to 50% missing taxa (matrices with ~40-55% missing data overall). Thus, our results show that simply excluding all missing data may be highly problematic as the primary guiding principle for the inclusion or exclusion of taxa and genes. The optimal strategy was somewhat different for each approach, a pattern that has not been shown previously. For concatenated analyses, branch support was maximized when including many taxa (44) but fewer characters (1.1 million). For species-tree analyses, branch support was maximized with minimal taxon sampling (16) but many loci (4789 of 4921). We also show that the choice of these sampling strategies can be critically important for phylogenomic analyses, since some strategies lead to demonstrably incorrect inferences (using the same method) that have strong statistical support. Our preferred estimate provides strong support for most interfamilial relationships in this important but phylogenetically challenging group. © The Author(s) 2015. Published by Oxford University Press, on behalf of the Society of Systematic Biologists. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
Cunningham, Michael R.; Baumeister, Roy F.
2016-01-01
The limited resource model states that self-control is governed by a relatively finite set of inner resources on which people draw when exerting willpower. Once self-control resources have been used up or depleted, they are less available for other self-control tasks, leading to a decrement in subsequent self-control success. The depletion effect has been studied for over 20 years, tested or extended in more than 600 studies, and supported in an independent meta-analysis (Hagger et al., 2010). Meta-analyses are supposed to reduce bias in literature reviews. Carter et al.’s (2015) meta-analysis, by contrast, included a series of questionable decisions involving sampling, methods, and data analysis. We provide quantitative analyses of key sampling issues: exclusion of many of the best depletion studies based on idiosyncratic criteria and the emphasis on mini meta-analyses with low statistical power as opposed to the overall depletion effect. We discuss two key methodological issues: failure to code for research quality, and the quantitative impact of weak studies by novice researchers. We discuss two key data analysis issues: questionable interpretation of the results of trim and fill and Funnel Plot Asymmetry test procedures, and the use and misinterpretation of the untested Precision Effect Test and Precision Effect Estimate with Standard Error (PEESE) procedures. Despite these serious problems, the Carter et al. (2015) meta-analysis results actually indicate that there is a real depletion effect – contrary to their title. PMID:27826272
Revising the Lubben Social Network Scale for use in residential long-term care settings.
Munn, Jean; Radey, Melissa; Brown, Kristin; Kim, Hyejin
2018-04-19
We revised the Lubben Social Network Scale (LSNS) to develop a measure of social support specific to residential long-term care (LTC) settings, the LSNS-LTC with five domains (i.e., family, friends, residents, volunteers, and staff). The authors modified the LSNS-18 to capture sources of social support specific to LTC, specifically relationships with residents, volunteers, and staff. We piloted the resultant 28-item measure with 64 LTC residents. Fifty-four respondents provided adequate information for analyses that included descriptive statistics and reliability coefficients. Twenty of the items performed well (had correlations >0.3, overall α = 0.85) and were retained. Three items required modification. The five items related to volunteers were eliminated due to extensive (>15%) missing data resulting in a proposed 23-item measure. We identified, and to some degree quantified, supportive relationships within the LTC environment, while developing a self-report tool to measure social support in these settings.
Characterizing Uncertainty and Variability in PBPK Models ...
Mode-of-action based risk and safety assessments can rely upon tissue dosimetry estimates in animals and humans obtained from physiologically-based pharmacokinetic (PBPK) modeling. However, risk assessment also increasingly requires characterization of uncertainty and variability; such characterization for PBPK model predictions represents a continuing challenge to both modelers and users. Current practices show significant progress in specifying deterministic biological models and the non-deterministic (often statistical) models, estimating their parameters using diverse data sets from multiple sources, and using them to make predictions and characterize uncertainty and variability. The International Workshop on Uncertainty and Variability in PBPK Models, held Oct 31-Nov 2, 2006, sought to identify the state-of-the-science in this area and recommend priorities for research and changes in practice and implementation. For the short term, these include: (1) multidisciplinary teams to integrate deterministic and non-deterministic/statistical models; (2) broader use of sensitivity analyses, including for structural and global (rather than local) parameter changes; and (3) enhanced transparency and reproducibility through more complete documentation of the model structure(s) and parameter values, the results of sensitivity and other analyses, and supporting, discrepant, or excluded data. Longer-term needs include: (1) theoretic and practical methodological impro
Trull, Timothy J; Vergés, Alvaro; Wood, Phillip K; Jahng, Seungmin; Sher, Kenneth J
2012-10-01
We examined the latent structure underlying the criteria for DSM-IV-TR (American Psychiatric Association, 2000, Diagnostic and statistical manual of mental disorders (4th ed., text revision). Washington, DC: Author.) personality disorders in a large nationally representative sample of U.S. adults. Personality disorder symptom data were collected using a structured diagnostic interview from approximately 35,000 adults assessed over two waves of data collection in the National Epidemiologic Survey on Alcohol and Related Conditions. Our analyses suggested that a seven-factor solution provided the best fit for the data, and these factors were marked primarily by one or at most two personality disorder criteria sets. A series of regression analyses that used external validators tapping Axis I psychopathology, treatment for mental health problems, functioning scores, interpersonal conflict, and suicidal ideation and behavior provided support for the seven-factor solution. We discuss these findings in the context of previous studies that have examined the structure underlying the personality disorder criteria as well as the current proposals for DSM-5 personality disorders. (PsycINFO Database Record (c) 2012 APA, all rights reserved).
Community Design Impacts on Health Habits in Low-income Southern Nevadans.
Coughenour, Courtney; Burns, Mackenzie S
2016-07-01
The purposes of this exploratory study were to: (1) characterize selected community design features; and (2) determine the relationship between select features and physical activity (PA) levels and nutrition habits for a small sample of low-income southern Nevadans. Secondary analysis was conducted on data from selected participants of the Nevada Healthy Homes Partnership program; self-report data on PA and diet habits were compared to national guidelines. Community design features were identified via GIS within a one-mile radius of participants' homes. Descriptive statistics characterized these features and chi-square analyses were conducted to determine the relationship between select features and habits. Data from 71 participants were analyzed; the majority failed to reach either PA or fruit and vegetable guidelines (81.7% and 93.0%, respectively). Many neighborhoods were absent of parks (71.8%), trailheads (36.6%), or pay-for-use PA facilities (47.9%). The mean number of grocery stores was 3.4 ± 2.3 per neighborhood. Chi-square analyses were not statistically significant. Findings were insufficient to make meaningful conclusions, but support the need for health promotion to meet guidelines. More research is needed to assess the impact of health-promoting community design and healthy behaviors, particularly in vulnerable populations.
[Organizational climate and burnout syndrome].
Lubrańska, Anna
2011-01-01
The paper addresses the issue of organizational climate and burnout syndrome. It has been assumed that burnout syndrome is dependent on work climate (organizational climate), therefore, two concepts were analyzed: by D. Kolb (organizational climate) and by Ch. Maslach (burnout syndrome). The research involved 239 persons (122 woman, 117 men), aged 21-66. In the study Maslach Burnout Inventory (MBI) and Inventory of Organizational Climate were used. The results of statistical methods (correlation analysis, one-variable analysis of variance and regression analysis) evidenced a strong relationship between organizational climate and burnout dimension. As depicted by the results, there are important differences in the level of burnout between the study participants who work in different types of organizational climate. The results of the statistical analyses indicate that the organizational climate determines burnout syndrome. Therefore, creating supportive conditions at the workplace might reduce the risk of burnout.
A psychometric evaluation of the Rorschach comprehensive system's perceptual thinking index.
Dao, Tam K; Prevatt, Frances
2006-04-01
In this study, we investigated evidence for reliability and validity of the Perceptual Thinking Index (PTI; Exner, 2000a, 2000b) among an adult inpatient population. We conducted reliability and validity analyses on 107 patients who met the Diagnostic and Statistical Manual of Mental Disorders (4th ed., text revision; American Psychiatric Association, 2000) criteria for a schizophrenia-spectrum disorder (SSD) or mood disorder with no psychotic features (MD). Results provided support for interrater reliability as well as internal consistency of the PTI. Furthermore, the PTI was an effective index in differentiating SSD patients from patients diagnosed with an MD. Finally, the PTI demonstrated adequate diagnostic statistics that can be useful in the classification of patients diagnosed with SSD and MD. We discuss methodological issues, implications for assessment practice, and directions for future research.
Testing for periodicity of extinction
NASA Technical Reports Server (NTRS)
Raup, David M.; Sepkoski, J. J., Jr.
1988-01-01
The statistical techniques used by Raup and Sepkoski (1984 and 1986) to identify a 26-Myr periodicity in the biological extinction record for the past 250 Myr are reexamined, responding in detail to the criticisms of Stigler and Wagner (1987). It is argued that evaluation of a much larger set of extinction data using a time scale with 51 sampling intervals supports the finding of periodicity. In a reply by Sigler and Wagner, the preference for a 26-Myr period is attributed to a numerical quirk in the Harland et al. (1982) time scale, in which the subinterval boundaries are not linear interpolations between the stage boundaries but have 25-Myr periodicity. It is stressed that the results of the stringent statistical tests imposed do not disprove periodicity but rather indicate that the evidence and analyses presented so far are inadequate.
1992-10-01
N=8) and Results of 44 Statistical Analyses for Impact Test Performed on Forefoot of Unworn Footwear A-2. Summary Statistics (N=8) and Results of...on Forefoot of Worn Footwear Vlll Tables (continued) Table Page B-2. Summary Statistics (N=4) and Results of 76 Statistical Analyses for Impact...used tests to assess heel and forefoot shock absorption, upper and sole durability, and flexibility (Cavanagh, 1978). Later, the number of tests was
2011-01-01
Background Clinical researchers have often preferred to use a fixed effects model for the primary interpretation of a meta-analysis. Heterogeneity is usually assessed via the well known Q and I2 statistics, along with the random effects estimate they imply. In recent years, alternative methods for quantifying heterogeneity have been proposed, that are based on a 'generalised' Q statistic. Methods We review 18 IPD meta-analyses of RCTs into treatments for cancer, in order to quantify the amount of heterogeneity present and also to discuss practical methods for explaining heterogeneity. Results Differing results were obtained when the standard Q and I2 statistics were used to test for the presence of heterogeneity. The two meta-analyses with the largest amount of heterogeneity were investigated further, and on inspection the straightforward application of a random effects model was not deemed appropriate. Compared to the standard Q statistic, the generalised Q statistic provided a more accurate platform for estimating the amount of heterogeneity in the 18 meta-analyses. Conclusions Explaining heterogeneity via the pre-specification of trial subgroups, graphical diagnostic tools and sensitivity analyses produced a more desirable outcome than an automatic application of the random effects model. Generalised Q statistic methods for quantifying and adjusting for heterogeneity should be incorporated as standard into statistical software. Software is provided to help achieve this aim. PMID:21473747
Analysis of a genetically structured variance heterogeneity model using the Box-Cox transformation.
Yang, Ye; Christensen, Ole F; Sorensen, Daniel
2011-02-01
Over recent years, statistical support for the presence of genetic factors operating at the level of the environmental variance has come from fitting a genetically structured heterogeneous variance model to field or experimental data in various species. Misleading results may arise due to skewness of the marginal distribution of the data. To investigate how the scale of measurement affects inferences, the genetically structured heterogeneous variance model is extended to accommodate the family of Box-Cox transformations. Litter size data in rabbits and pigs that had previously been analysed in the untransformed scale were reanalysed in a scale equal to the mode of the marginal posterior distribution of the Box-Cox parameter. In the rabbit data, the statistical evidence for a genetic component at the level of the environmental variance is considerably weaker than that resulting from an analysis in the original metric. In the pig data, the statistical evidence is stronger, but the coefficient of correlation between additive genetic effects affecting mean and variance changes sign, compared to the results in the untransformed scale. The study confirms that inferences on variances can be strongly affected by the presence of asymmetry in the distribution of data. We recommend that to avoid one important source of spurious inferences, future work seeking support for a genetic component acting on environmental variation using a parametric approach based on normality assumptions confirms that these are met.
Fichman, Martin; Keelan, Jennifer E
2007-09-01
In the 1880s, Alfred Russel Wallace, the celebrated co-discoverer of natural selection, launched himself into the centre of a politicised and polarised debate over the unpopular compulsory vaccination laws in England. Wallace never wavered in his belief that smallpox vaccination was useless and likely dangerous. Six years before his death, the anti-vaccinationists successfully secured a conscience clause that effectively dismantled the compulsory vaccination laws. Several other important Victorian scientists joined Wallace in the fight to repeal compulsory vaccination arguing that widely held views on the effectiveness of vaccination and evidence for immunity were inconclusive in the light of (then) contemporary standards of evidence. This article situates Wallace's anti-vaccination logic within the broader matrix of sociopolitical and cultural reform movements of the late Victorian era. Additionally it provides the first detailed analysis of his critique of vaccination science, in particular the role statistics played in his arguments. In this period, both pro-vaccinationists and anti-vaccinationists invested great efforts in collating and analysing statistical data sets that either supported or refuted the claims of vaccination's effectiveness. While each side presented 'controlled' case studies to support their assertions, without an unambiguous test to measure or demonstrate vaccination's effectiveness, the anti-vaccinationists continued to mount credible statistical critiques of vaccination science.
Gaskin, Cadeyrn J; Happell, Brenda
2014-05-01
To (a) assess the statistical power of nursing research to detect small, medium, and large effect sizes; (b) estimate the experiment-wise Type I error rate in these studies; and (c) assess the extent to which (i) a priori power analyses, (ii) effect sizes (and interpretations thereof), and (iii) confidence intervals were reported. Statistical review. Papers published in the 2011 volumes of the 10 highest ranked nursing journals, based on their 5-year impact factors. Papers were assessed for statistical power, control of experiment-wise Type I error, reporting of a priori power analyses, reporting and interpretation of effect sizes, and reporting of confidence intervals. The analyses were based on 333 papers, from which 10,337 inferential statistics were identified. The median power to detect small, medium, and large effect sizes was .40 (interquartile range [IQR]=.24-.71), .98 (IQR=.85-1.00), and 1.00 (IQR=1.00-1.00), respectively. The median experiment-wise Type I error rate was .54 (IQR=.26-.80). A priori power analyses were reported in 28% of papers. Effect sizes were routinely reported for Spearman's rank correlations (100% of papers in which this test was used), Poisson regressions (100%), odds ratios (100%), Kendall's tau correlations (100%), Pearson's correlations (99%), logistic regressions (98%), structural equation modelling/confirmatory factor analyses/path analyses (97%), and linear regressions (83%), but were reported less often for two-proportion z tests (50%), analyses of variance/analyses of covariance/multivariate analyses of variance (18%), t tests (8%), Wilcoxon's tests (8%), Chi-squared tests (8%), and Fisher's exact tests (7%), and not reported for sign tests, Friedman's tests, McNemar's tests, multi-level models, and Kruskal-Wallis tests. Effect sizes were infrequently interpreted. Confidence intervals were reported in 28% of papers. The use, reporting, and interpretation of inferential statistics in nursing research need substantial improvement. Most importantly, researchers should abandon the misleading practice of interpreting the results from inferential tests based solely on whether they are statistically significant (or not) and, instead, focus on reporting and interpreting effect sizes, confidence intervals, and significance levels. Nursing researchers also need to conduct and report a priori power analyses, and to address the issue of Type I experiment-wise error inflation in their studies. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.
ERIC Educational Resources Information Center
Perepiczka, Michelle; Chandler, Nichelle; Becerra, Michael
2011-01-01
Statistics plays an integral role in graduate programs. However, numerous intra- and interpersonal factors may lead to successful completion of needed coursework in this area. The authors examined the extent of the relationship between self-efficacy to learn statistics and statistics anxiety, attitude towards statistics, and social support of 166…
NASA Astrophysics Data System (ADS)
Flores-Marquez, Leticia Elsa; Ramirez Rojaz, Alejandro; Telesca, Luciano
2015-04-01
The study of two statistical approaches is analyzed for two different types of data sets, one is the seismicity generated by the subduction processes occurred at south Pacific coast of Mexico between 2005 and 2012, and the other corresponds to the synthetic seismic data generated by a stick-slip experimental model. The statistical methods used for the present study are the visibility graph in order to investigate the time dynamics of the series and the scaled probability density function in the natural time domain to investigate the critical order of the system. This comparison has the purpose to show the similarities between the dynamical behaviors of both types of data sets, from the point of view of critical systems. The observed behaviors allow us to conclude that the experimental set up globally reproduces the behavior observed in the statistical approaches used to analyses the seismicity of the subduction zone. The present study was supported by the Bilateral Project Italy-Mexico Experimental Stick-slip models of tectonic faults: innovative statistical approaches applied to synthetic seismic sequences, jointly funded by MAECI (Italy) and AMEXCID (Mexico) in the framework of the Bilateral Agreement for Scientific and Technological Cooperation PE 2014-2016.
Harding, Kaitlin A.; Willey, Brittany; Ahles, Joshua; Mezulis, Amy
2016-01-01
Background Trait negative affect and trait positive affect are affective vulnerabilities to depressive symptoms in adolescence and adulthood. While trait affect and the state affect characteristic of depressive symptoms are proposed to be theoretically distinct, no studies have established that these constructs are statistically distinct. Therefore, the purpose of the current study was to determine whether the trait affect (e.g. temperament dimensions) that predicts depressive symptoms and the state affect characteristic of depressive symptoms are statistically distinct among early adolescents and adults. We hypothesized that trait negative affect, trait positive affect, and depressive symptoms would represent largely distinct factors in both samples. Method Participants were 268 early adolescents (53.73% female) and 321 young adults (70.09% female) who completed self-report measures of demographic information, trait affect, and depressive symptoms. Results Principal axis factoring with oblique rotation for both samples indicated distinct adolescent factor loadings and overlapping adult factor loadings. Confirmatory factor analyses in both samples supported distinct but related relationships between trait NA, trait PA, and depressive symptoms. Limitations Study limitations include our cross-sectional design that prevented examination of self-reported fluctuations in trait affect and depressive symptoms and the unknown potential effects of self-report biases among adolescents and adults. Conclusions Findings support existing theoretical distinctions between adolescent constructs but highlight a need to revise or remove items to distinguish measurements of adult trait affect and depressive symptoms. Adolescent trait affect and depressive symptoms are statistically distinct, but adult trait affect and depressive symptoms statistically overlap and warrant further consideration. PMID:27085163
Cost-effectiveness of two vocational rehabilitation programs for persons with severe mental illness.
Dixon, Lisa; Hoch, Jeffrey S; Clark, Robin; Bebout, Richard; Drake, Robert; McHugo, Greg; Becker, Deborah
2002-09-01
This study sought to determine differences in the cost-effectiveness of two vocational programs: individual placement and support (IPS), in which employment specialists within a mental health center help patients obtain competitive jobs and provide them with ongoing support, and enhanced vocational rehabilitation (EVR), in which stepwise services that involve prevocational experiences are delivered by rehabilitation agencies. A total of 150 unemployed inner-city patients with severe mental disorders who expressed an interest in competitive employment were randomly assigned to IPS or EVR programs and were followed for 18 months. Wages from all forms of employment and the number of weeks and hours of competitive employment were tracked monthly. Estimates were made of direct mental health costs and vocational costs. Incremental cost-effectiveness ratios (ICERs) were calculated for competitive employment outcomes and total wages. No statistically significant differences were found in the overall costs of IPS and EVR. Participation in the IPS program was associated with significantly more hours and weeks of competitive employment. However, the average combined earnings-earnings from competitive and noncompetitive employment-were virtually the same both programs. The ICER estimates indicated that participants in the IPS program worked in competitive employment settings for an additional week over the 18-month period at a cost of $283 ($13 an hour). The analyses suggest that IPS participants engaged in competitive employment at a higher cost. When combined earnings were used as the outcome, data from the statistical analyses were insufficient to enable any firm conclusions to be drawn. The findings illustrate the importance of choice of outcomes in evaluations of employment programs.
Neti, Prasad V.S.V.; Howell, Roger W.
2008-01-01
Recently, the distribution of radioactivity among a population of cells labeled with 210Po was shown to be well described by a log normal distribution function (J Nucl Med 47, 6 (2006) 1049-1058) with the aid of an autoradiographic approach. To ascertain the influence of Poisson statistics on the interpretation of the autoradiographic data, the present work reports on a detailed statistical analyses of these data. Methods The measured distributions of alpha particle tracks per cell were subjected to statistical tests with Poisson (P), log normal (LN), and Poisson – log normal (P – LN) models. Results The LN distribution function best describes the distribution of radioactivity among cell populations exposed to 0.52 and 3.8 kBq/mL 210Po-citrate. When cells were exposed to 67 kBq/mL, the P – LN distribution function gave a better fit, however, the underlying activity distribution remained log normal. Conclusions The present analysis generally provides further support for the use of LN distributions to describe the cellular uptake of radioactivity. Care should be exercised when analyzing autoradiographic data on activity distributions to ensure that Poisson processes do not distort the underlying LN distribution. PMID:16741316
Bluhmki, Tobias; Bramlage, Peter; Volk, Michael; Kaltheuner, Matthias; Danne, Thomas; Rathmann, Wolfgang; Beyersmann, Jan
2017-02-01
Complex longitudinal sampling and the observational structure of patient registers in health services research are associated with methodological challenges regarding data management and statistical evaluation. We exemplify common pitfalls and want to stimulate discussions on the design, development, and deployment of future longitudinal patient registers and register-based studies. For illustrative purposes, we use data from the prospective, observational, German DIabetes Versorgungs-Evaluation register. One aim was to explore predictors for the initiation of a basal insulin supported therapy in patients with type 2 diabetes initially prescribed to glucose-lowering drugs alone. Major challenges are missing mortality information, time-dependent outcomes, delayed study entries, different follow-up times, and competing events. We show that time-to-event methodology is a valuable tool for improved statistical evaluation of register data and should be preferred to simple case-control approaches. Patient registers provide rich data sources for health services research. Analyses are accompanied with the trade-off between data availability, clinical plausibility, and statistical feasibility. Cox' proportional hazards model allows for the evaluation of the outcome-specific hazards, but prediction of outcome probabilities is compromised by missing mortality information. Copyright © 2016 Elsevier Inc. All rights reserved.
Statistical Methods Applied to Gamma-ray Spectroscopy Algorithms in Nuclear Security Missions
DOE Office of Scientific and Technical Information (OSTI.GOV)
Fagan, Deborah K.; Robinson, Sean M.; Runkle, Robert C.
2012-10-01
In a wide range of nuclear security missions, gamma-ray spectroscopy is a critical research and development priority. One particularly relevant challenge is the interdiction of special nuclear material for which gamma-ray spectroscopy supports the goals of detecting and identifying gamma-ray sources. This manuscript examines the existing set of spectroscopy methods, attempts to categorize them by the statistical methods on which they rely, and identifies methods that have yet to be considered. Our examination shows that current methods effectively estimate the effect of counting uncertainty but in many cases do not address larger sources of decision uncertainty—ones that are significantly moremore » complex. We thus explore the premise that significantly improving algorithm performance requires greater coupling between the problem physics that drives data acquisition and statistical methods that analyze such data. Untapped statistical methods, such as Bayes Modeling Averaging and hierarchical and empirical Bayes methods have the potential to reduce decision uncertainty by more rigorously and comprehensively incorporating all sources of uncertainty. We expect that application of such methods will demonstrate progress in meeting the needs of nuclear security missions by improving on the existing numerical infrastructure for which these analyses have not been conducted.« less
a Statistical Texture Feature for Building Collapse Information Extraction of SAR Image
NASA Astrophysics Data System (ADS)
Li, L.; Yang, H.; Chen, Q.; Liu, X.
2018-04-01
Synthetic Aperture Radar (SAR) has become one of the most important ways to extract post-disaster collapsed building information, due to its extreme versatility and almost all-weather, day-and-night working capability, etc. In view of the fact that the inherent statistical distribution of speckle in SAR images is not used to extract collapsed building information, this paper proposed a novel texture feature of statistical models of SAR images to extract the collapsed buildings. In the proposed feature, the texture parameter of G0 distribution from SAR images is used to reflect the uniformity of the target to extract the collapsed building. This feature not only considers the statistical distribution of SAR images, providing more accurate description of the object texture, but also is applied to extract collapsed building information of single-, dual- or full-polarization SAR data. The RADARSAT-2 data of Yushu earthquake which acquired on April 21, 2010 is used to present and analyze the performance of the proposed method. In addition, the applicability of this feature to SAR data with different polarizations is also analysed, which provides decision support for the data selection of collapsed building information extraction.
Berry, Donald A.; Ueno, Naoto T.; Johnson, Marcella M.; Lei, Xiudong; Caputo, Jean; Smith, Dori A.; Yancey, Linda J.; Crump, Michael; Stadtmauer, Edward A.; Biron, Pierre; Crown, John P.; Schmid, Peter; Lotz, Jean-Pierre; Rosti, Giovanni; Bregni, Marco; Demirer, Taner
2011-01-01
Purpose High doses of effective chemotherapy are compelling if they can be delivered safely. Substantial interest in supporting high-dose chemotherapy with bone marrow or autologous hematopoietic stem-cell transplantation in the 1980s and 1990s led to the initiation of randomized trials to evaluate its effect in the treatment of metastatic breast cancer. Methods We identified six randomized trials in metastatic breast cancer that evaluated high doses of chemotherapy with transplant support versus a control regimen without stem-cell support. We assembled a single database containing individual patient information from these trials. The primary analysis of overall survival was a log-rank test comparing high dose versus control. We also used Cox proportional hazards regression, adjusting for known covariates. We addressed potential treatment differences within subsets of patients. Results The effect of high-dose chemotherapy on overall survival was not statistically different (median, 2.16 v 2.02 years; P = .08). A statistically significant advantage in progression-free survival (median, 0.91 v 0.69 years) did not translate into survival benefit. Subset analyses found little evidence that there are groups of patients who might benefit from high-dose chemotherapy with hematopoietic support. Conclusion Overall survival of patients with metastatic breast cancer in the six randomized trials was not significantly improved by high-dose chemotherapy; any benefit from high doses was small. No identifiable subset of patients seems to benefit from high-dose chemotherapy. PMID:21768454
Wildfire cluster detection using space-time scan statistics
NASA Astrophysics Data System (ADS)
Tonini, M.; Tuia, D.; Ratle, F.; Kanevski, M.
2009-04-01
The aim of the present study is to identify spatio-temporal clusters of fires sequences using space-time scan statistics. These statistical methods are specifically designed to detect clusters and assess their significance. Basically, scan statistics work by comparing a set of events occurring inside a scanning window (or a space-time cylinder for spatio-temporal data) with those that lie outside. Windows of increasing size scan the zone across space and time: the likelihood ratio is calculated for each window (comparing the ratio "observed cases over expected" inside and outside): the window with the maximum value is assumed to be the most probable cluster, and so on. Under the null hypothesis of spatial and temporal randomness, these events are distributed according to a known discrete-state random process (Poisson or Bernoulli), which parameters can be estimated. Given this assumption, it is possible to test whether or not the null hypothesis holds in a specific area. In order to deal with fires data, the space-time permutation scan statistic has been applied since it does not require the explicit specification of the population-at risk in each cylinder. The case study is represented by Florida daily fire detection using the Moderate Resolution Imaging Spectroradiometer (MODIS) active fire product during the period 2003-2006. As result, statistically significant clusters have been identified. Performing the analyses over the entire frame period, three out of the five most likely clusters have been identified in the forest areas, on the North of the country; the other two clusters cover a large zone in the South, corresponding to agricultural land and the prairies in the Everglades. Furthermore, the analyses have been performed separately for the four years to analyze if the wildfires recur each year during the same period. It emerges that clusters of forest fires are more frequent in hot seasons (spring and summer), while in the South areas they are widely present along the whole year. The analysis of fires distribution to evaluate if they are statistically more frequent in some area or/and in some period of the year, can be useful to support fire management and to focus on prevention measures.
40 CFR 91.512 - Request for public hearing.
Code of Federal Regulations, 2010 CFR
2010-07-01
... plans and statistical analyses have been properly applied (specifically, whether sampling procedures and statistical analyses specified in this subpart were followed and whether there exists a basis for... will be made available to the public during Agency business hours. ...
Jin, Zhichao; Yu, Danghui; Zhang, Luoman; Meng, Hong; Lu, Jian; Gao, Qingbin; Cao, Yang; Ma, Xiuqiang; Wu, Cheng; He, Qian; Wang, Rui; He, Jia
2010-05-25
High quality clinical research not only requires advanced professional knowledge, but also needs sound study design and correct statistical analyses. The number of clinical research articles published in Chinese medical journals has increased immensely in the past decade, but study design quality and statistical analyses have remained suboptimal. The aim of this investigation was to gather evidence on the quality of study design and statistical analyses in clinical researches conducted in China for the first decade of the new millennium. Ten (10) leading Chinese medical journals were selected and all original articles published in 1998 (N = 1,335) and 2008 (N = 1,578) were thoroughly categorized and reviewed. A well-defined and validated checklist on study design, statistical analyses, results presentation, and interpretation was used for review and evaluation. Main outcomes were the frequencies of different types of study design, error/defect proportion in design and statistical analyses, and implementation of CONSORT in randomized clinical trials. From 1998 to 2008: The error/defect proportion in statistical analyses decreased significantly ( = 12.03, p<0.001), 59.8% (545/1,335) in 1998 compared to 52.2% (664/1,578) in 2008. The overall error/defect proportion of study design also decreased ( = 21.22, p<0.001), 50.9% (680/1,335) compared to 42.40% (669/1,578). In 2008, design with randomized clinical trials remained low in single digit (3.8%, 60/1,578) with two-third showed poor results reporting (defects in 44 papers, 73.3%). Nearly half of the published studies were retrospective in nature, 49.3% (658/1,335) in 1998 compared to 48.2% (761/1,578) in 2008. Decreases in defect proportions were observed in both results presentation ( = 93.26, p<0.001), 92.7% (945/1,019) compared to 78.2% (1023/1,309) and interpretation ( = 27.26, p<0.001), 9.7% (99/1,019) compared to 4.3% (56/1,309), some serious ones persisted. Chinese medical research seems to have made significant progress regarding statistical analyses, but there remains ample room for improvement regarding study designs. Retrospective clinical studies are the most often used design, whereas randomized clinical trials are rare and often show methodological weaknesses. Urgent implementation of the CONSORT statement is imperative.
Lopes, Vagner José; Shmeil, Marcos Augusto Hochuli
2017-04-27
To compare computer-generated guidelines with and without the use of a Clinical Decision Support System - Oncology Care and Healthcare for Chemotherapy Patients, for the caregivers of children undergoing chemotherapy. This is a descriptive, evaluative, and quantitative study conducted at a paediatrics hospital in Curitiba, Paraná, Brazil, from December 2015 to January 2016. The sample consisted of 58 participants divided into two groups: Group 1, without the aid of software, and Group 2, with the aid of the software. The data were analysed using the Mann-Whitney U test. The guidelines revealed a statistical significance (p<0.05), with a prevalence of a higher concordance average in Group 2 in comparison with Group 1. Computer-generated guidelines are a valuable qualitative support tool for nurses.
Tools to Support Interpreting Multiple Regression in the Face of Multicollinearity
Kraha, Amanda; Turner, Heather; Nimon, Kim; Zientek, Linda Reichwein; Henson, Robin K.
2012-01-01
While multicollinearity may increase the difficulty of interpreting multiple regression (MR) results, it should not cause undue problems for the knowledgeable researcher. In the current paper, we argue that rather than using one technique to investigate regression results, researchers should consider multiple indices to understand the contributions that predictors make not only to a regression model, but to each other as well. Some of the techniques to interpret MR effects include, but are not limited to, correlation coefficients, beta weights, structure coefficients, all possible subsets regression, commonality coefficients, dominance weights, and relative importance weights. This article will review a set of techniques to interpret MR effects, identify the elements of the data on which the methods focus, and identify statistical software to support such analyses. PMID:22457655
Tools to support interpreting multiple regression in the face of multicollinearity.
Kraha, Amanda; Turner, Heather; Nimon, Kim; Zientek, Linda Reichwein; Henson, Robin K
2012-01-01
While multicollinearity may increase the difficulty of interpreting multiple regression (MR) results, it should not cause undue problems for the knowledgeable researcher. In the current paper, we argue that rather than using one technique to investigate regression results, researchers should consider multiple indices to understand the contributions that predictors make not only to a regression model, but to each other as well. Some of the techniques to interpret MR effects include, but are not limited to, correlation coefficients, beta weights, structure coefficients, all possible subsets regression, commonality coefficients, dominance weights, and relative importance weights. This article will review a set of techniques to interpret MR effects, identify the elements of the data on which the methods focus, and identify statistical software to support such analyses.
ERIC Educational Resources Information Center
Cafri, Guy; Kromrey, Jeffrey D.; Brannick, Michael T.
2010-01-01
This article uses meta-analyses published in "Psychological Bulletin" from 1995 to 2005 to describe meta-analyses in psychology, including examination of statistical power, Type I errors resulting from multiple comparisons, and model choice. Retrospective power estimates indicated that univariate categorical and continuous moderators, individual…
Algorithm for Identifying Erroneous Rain-Gauge Readings
NASA Technical Reports Server (NTRS)
Rickman, Doug
2005-01-01
An algorithm analyzes rain-gauge data to identify statistical outliers that could be deemed to be erroneous readings. Heretofore, analyses of this type have been performed in burdensome manual procedures that have involved subjective judgements. Sometimes, the analyses have included computational assistance for detecting values falling outside of arbitrary limits. The analyses have been performed without statistically valid knowledge of the spatial and temporal variations of precipitation within rain events. In contrast, the present algorithm makes it possible to automate such an analysis, makes the analysis objective, takes account of the spatial distribution of rain gauges in conjunction with the statistical nature of spatial variations in rainfall readings, and minimizes the use of arbitrary criteria. The algorithm implements an iterative process that involves nonparametric statistics.
Citation of previous meta-analyses on the same topic: a clue to perpetuation of incorrect methods?
Li, Tianjing; Dickersin, Kay
2013-06-01
Systematic reviews and meta-analyses serve as a basis for decision-making and clinical practice guidelines and should be carried out using appropriate methodology to avoid incorrect inferences. We describe the characteristics, statistical methods used for meta-analyses, and citation patterns of all 21 glaucoma systematic reviews we identified pertaining to the effectiveness of prostaglandin analog eye drops in treating primary open-angle glaucoma, published between December 2000 and February 2012. We abstracted data, assessed whether appropriate statistical methods were applied in meta-analyses, and examined citation patterns of included reviews. We identified two forms of problematic statistical analyses in 9 of the 21 systematic reviews examined. Except in 1 case, none of the 9 reviews that used incorrect statistical methods cited a previously published review that used appropriate methods. Reviews that used incorrect methods were cited 2.6 times more often than reviews that used appropriate statistical methods. We speculate that by emulating the statistical methodology of previous systematic reviews, systematic review authors may have perpetuated incorrect approaches to meta-analysis. The use of incorrect statistical methods, perhaps through emulating methods described in previous research, calls conclusions of systematic reviews into question and may lead to inappropriate patient care. We urge systematic review authors and journal editors to seek the advice of experienced statisticians before undertaking or accepting for publication a systematic review and meta-analysis. The author(s) have no proprietary or commercial interest in any materials discussed in this article. Copyright © 2013 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.
Vainik, Uku; Konstabel, Kenn; Lätt, Evelin; Mäestu, Jarek; Purge, Priit; Jürimäe, Jaak
2016-10-01
Subjective energy intake (sEI) is often misreported, providing unreliable estimates of energy consumed. Therefore, relating sEI data to health outcomes is difficult. Recently, Börnhorst et al. compared various methods to correct sEI-based energy intake estimates. They criticised approaches that categorise participants as under-reporters, plausible reporters and over-reporters based on the sEI:total energy expenditure (TEE) ratio, and thereafter use these categories as statistical covariates or exclusion criteria. Instead, they recommended using external predictors of sEI misreporting as statistical covariates. We sought to confirm and extend these findings. Using a sample of 190 adolescent boys (mean age=14), we demonstrated that dual-energy X-ray absorptiometry-measured fat-free mass is strongly associated with objective energy intake data (onsite weighted breakfast), but the association with sEI (previous 3-d dietary interview) is weak. Comparing sEI with TEE revealed that sEI was mostly under-reported (74 %). Interestingly, statistically controlling for dietary reporting groups or restricting samples to plausible reporters created a stronger-than-expected association between fat-free mass and sEI. However, the association was an artifact caused by selection bias - that is, data re-sampling and simulations showed that these methods overestimated the effect size because fat-free mass was related to sEI both directly and indirectly via TEE. A more realistic association between sEI and fat-free mass was obtained when the model included common predictors of misreporting (e.g. BMI, restraint). To conclude, restricting sEI data only to plausible reporters can cause selection bias and inflated associations in later analyses. Therefore, we further support statistically correcting sEI data in nutritional analyses. The script for running simulations is provided.
Jackson, Dan; Bowden, Jack
2016-09-07
Confidence intervals for the between study variance are useful in random-effects meta-analyses because they quantify the uncertainty in the corresponding point estimates. Methods for calculating these confidence intervals have been developed that are based on inverting hypothesis tests using generalised heterogeneity statistics. Whilst, under the random effects model, these new methods furnish confidence intervals with the correct coverage, the resulting intervals are usually very wide, making them uninformative. We discuss a simple strategy for obtaining 95 % confidence intervals for the between-study variance with a markedly reduced width, whilst retaining the nominal coverage probability. Specifically, we consider the possibility of using methods based on generalised heterogeneity statistics with unequal tail probabilities, where the tail probability used to compute the upper bound is greater than 2.5 %. This idea is assessed using four real examples and a variety of simulation studies. Supporting analytical results are also obtained. Our results provide evidence that using unequal tail probabilities can result in shorter 95 % confidence intervals for the between-study variance. We also show some further results for a real example that illustrates how shorter confidence intervals for the between-study variance can be useful when performing sensitivity analyses for the average effect, which is usually the parameter of primary interest. We conclude that using unequal tail probabilities when computing 95 % confidence intervals for the between-study variance, when using methods based on generalised heterogeneity statistics, can result in shorter confidence intervals. We suggest that those who find the case for using unequal tail probabilities convincing should use the '1-4 % split', where greater tail probability is allocated to the upper confidence bound. The 'width-optimal' interval that we present deserves further investigation.
Jezberová, Jitka; Jezbera, Jan; Brandt, Ulrike; Lindström, Eva S.; Langenheder, Silke; Hahn, Martin W.
2010-01-01
Summary We present a survey on the distribution and habitat range of P. necessarius subspecies asymbioticus (PnecC), an important taxon in the water column of freshwater systems. We systematically sampled stagnant freshwater habitats in a heterogeneous 2000 km2 area, together with ecologically different habitats outside this area. In total, 137 lakes, ponds and puddles were investigated, which represent an enormous diversity of habitats differing, i.e., in depth (<10 cm – 171 m) and pH (3.9 – 8.5). PnecC was detected by cultivation-independent methods in all investigated habitats, and its presence was confirmed by cultivation of strains from selected habitats including the most extreme ones. The determined relative abundance of the subspecies ranged from slightly above 0% to 67% (average 14.5% ± 14.3%), and the highest observed absolute abundance was 5.3×106 cells mL−1. Statistical analyses revealed that the abundance of PnecC is partially controlled by factors linked to concentrations of humic substances, which might support the hypothesis that these bacteria utilize photodegradation products of humic substances. . Statistical analyses revealed that the abundance of PnecC is partially controlled by low conductivity and pH and factors linked to concentrations of humic substances. Based on the revealed statistical relationships, an average relative abundance of this subspecies of 20% in global freshwater habitats was extrapolated. Our study provides important implications for the current debate on ubiquity and biogeography in microorganisms. PMID:20041938
Wu, Robert; Glen, Peter; Ramsay, Tim; Martel, Guillaume
2014-06-28
Observational studies dominate the surgical literature. Statistical adjustment is an important strategy to account for confounders in observational studies. Research has shown that published articles are often poor in statistical quality, which may jeopardize their conclusions. The Statistical Analyses and Methods in the Published Literature (SAMPL) guidelines have been published to help establish standards for statistical reporting.This study will seek to determine whether the quality of statistical adjustment and the reporting of these methods are adequate in surgical observational studies. We hypothesize that incomplete reporting will be found in all surgical observational studies, and that the quality and reporting of these methods will be of lower quality in surgical journals when compared with medical journals. Finally, this work will seek to identify predictors of high-quality reporting. This work will examine the top five general surgical and medical journals, based on a 5-year impact factor (2007-2012). All observational studies investigating an intervention related to an essential component area of general surgery (defined by the American Board of Surgery), with an exposure, outcome, and comparator, will be included in this systematic review. Essential elements related to statistical reporting and quality were extracted from the SAMPL guidelines and include domains such as intent of analysis, primary analysis, multiple comparisons, numbers and descriptive statistics, association and correlation analyses, linear regression, logistic regression, Cox proportional hazard analysis, analysis of variance, survival analysis, propensity analysis, and independent and correlated analyses. Each article will be scored as a proportion based on fulfilling criteria in relevant analyses used in the study. A logistic regression model will be built to identify variables associated with high-quality reporting. A comparison will be made between the scores of surgical observational studies published in medical versus surgical journals. Secondary outcomes will pertain to individual domains of analysis. Sensitivity analyses will be conducted. This study will explore the reporting and quality of statistical analyses in surgical observational studies published in the most referenced surgical and medical journals in 2013 and examine whether variables (including the type of journal) can predict high-quality reporting.
Sadat, Umar
2014-01-01
Contrast-induced acute kidney injury (CI-AKI) is one of the most widely discussed and debated topic in cardiovascular medicine and N-acetylcysteine (NAC) is the most widely used pharmacological agent assessed in clinical trials for offering renal protection against CI-AKI. Results of these clinical trials are though split between those that favor its use and vice versa. In this brief communication we discuss the latest research advances regarding the use of NAC against CI-AKI. Recent clinical evidence and overview of in-depth statistical analyses of relevant clinical trials and their meta-analyses do not support the use of NAC in prophylaxis against CI-AKI. Adequate hydration before and after contrast media exposure, along with avoidance of nephrotoxic drugs, remains the recommended prophylaxis against CI-AKI.
Statistical analyses of commercial vehicle accident factors. Volume 1 Part 1
DOT National Transportation Integrated Search
1978-02-01
Procedures for conducting statistical analyses of commercial vehicle accidents have been established and initially applied. A file of some 3,000 California Highway Patrol accident reports from two areas of California during a period of about one year...
40 CFR 90.712 - Request for public hearing.
Code of Federal Regulations, 2010 CFR
2010-07-01
... sampling plans and statistical analyses have been properly applied (specifically, whether sampling procedures and statistical analyses specified in this subpart were followed and whether there exists a basis... Clerk and will be made available to the public during Agency business hours. ...
Supply Chain Collaboration: Information Sharing in a Tactical Operating Environment
2013-06-01
architecture, there are four tiers: Client (Web Application Clients ), Presentation (Web-Server), Processing (Application-Server), Data (Database...organization in each period. This data will be collected to analyze. i) Analyses and Validation: We will do a statistics test in this data, Pareto ...notes, outstanding deliveries, and inventory. i) Analyses and Validation: We will do a statistics test in this data, Pareto analyses and confirmation
On Designing Multicore-Aware Simulators for Systems Biology Endowed with OnLine Statistics
Calcagno, Cristina; Coppo, Mario
2014-01-01
The paper arguments are on enabling methodologies for the design of a fully parallel, online, interactive tool aiming to support the bioinformatics scientists .In particular, the features of these methodologies, supported by the FastFlow parallel programming framework, are shown on a simulation tool to perform the modeling, the tuning, and the sensitivity analysis of stochastic biological models. A stochastic simulation needs thousands of independent simulation trajectories turning into big data that should be analysed by statistic and data mining tools. In the considered approach the two stages are pipelined in such a way that the simulation stage streams out the partial results of all simulation trajectories to the analysis stage that immediately produces a partial result. The simulation-analysis workflow is validated for performance and effectiveness of the online analysis in capturing biological systems behavior on a multicore platform and representative proof-of-concept biological systems. The exploited methodologies include pattern-based parallel programming and data streaming that provide key features to the software designers such as performance portability and efficient in-memory (big) data management and movement. Two paradigmatic classes of biological systems exhibiting multistable and oscillatory behavior are used as a testbed. PMID:25050327
Neandertal admixture in Eurasia confirmed by maximum-likelihood analysis of three genomes.
Lohse, Konrad; Frantz, Laurent A F
2014-04-01
Although there has been much interest in estimating histories of divergence and admixture from genomic data, it has proved difficult to distinguish recent admixture from long-term structure in the ancestral population. Thus, recent genome-wide analyses based on summary statistics have sparked controversy about the possibility of interbreeding between Neandertals and modern humans in Eurasia. Here we derive the probability of full mutational configurations in nonrecombining sequence blocks under both admixture and ancestral structure scenarios. Dividing the genome into short blocks gives an efficient way to compute maximum-likelihood estimates of parameters. We apply this likelihood scheme to triplets of human and Neandertal genomes and compare the relative support for a model of admixture from Neandertals into Eurasian populations after their expansion out of Africa against a history of persistent structure in their common ancestral population in Africa. Our analysis allows us to conclusively reject a model of ancestral structure in Africa and instead reveals strong support for Neandertal admixture in Eurasia at a higher rate (3.4-7.3%) than suggested previously. Using analysis and simulations we show that our inference is more powerful than previous summary statistics and robust to realistic levels of recombination.
Influence of laser-welding and electroerosion on passive fit of implant-supported prosthesis.
Silva, Tatiana Bernardon; De Arruda Nobilo, Mauro Antonio; Pessanha Henriques, Guilherme Elias; Mesquita, Marcelo Ferraz; Guimaraes, Magali Beck
2008-01-01
This study investigated the influence of laser welding and electroerosion procedure on the passive fit of interim fixed implant-supported titanium frameworks. Twenty frameworks were made from a master model, with five parallel placed implants in the inter foramen region, and cast in commercially pure titanium. The frameworks were divided into 4 groups: 10 samples were tested before (G1) and after (G2) electroerosion application; and another 10 were sectioned into five pieces and laser welded before (G3) and after (G4) electroerosion application. The passive fit between the UCLA abutment of the framework and the implant was evaluated using an optical microscope Olympus STM (Olympus Optical Co., Tokyo, Japan) with 0.0005mm of accuracy. Statistical analyses showed significant differences between G1 and G2, G1 and G3, G1 and G4, G2 and G4. However, no statistical difference was observed when comparing G2 and G3. These results indicate that frameworks may show a more precise adaptation if they are sectioned and laser welded. In the same way, electroerosion improves the precision in the framework adaptation.
Neandertal Admixture in Eurasia Confirmed by Maximum-Likelihood Analysis of Three Genomes
Lohse, Konrad; Frantz, Laurent A. F.
2014-01-01
Although there has been much interest in estimating histories of divergence and admixture from genomic data, it has proved difficult to distinguish recent admixture from long-term structure in the ancestral population. Thus, recent genome-wide analyses based on summary statistics have sparked controversy about the possibility of interbreeding between Neandertals and modern humans in Eurasia. Here we derive the probability of full mutational configurations in nonrecombining sequence blocks under both admixture and ancestral structure scenarios. Dividing the genome into short blocks gives an efficient way to compute maximum-likelihood estimates of parameters. We apply this likelihood scheme to triplets of human and Neandertal genomes and compare the relative support for a model of admixture from Neandertals into Eurasian populations after their expansion out of Africa against a history of persistent structure in their common ancestral population in Africa. Our analysis allows us to conclusively reject a model of ancestral structure in Africa and instead reveals strong support for Neandertal admixture in Eurasia at a higher rate (3.4−7.3%) than suggested previously. Using analysis and simulations we show that our inference is more powerful than previous summary statistics and robust to realistic levels of recombination. PMID:24532731
On designing multicore-aware simulators for systems biology endowed with OnLine statistics.
Aldinucci, Marco; Calcagno, Cristina; Coppo, Mario; Damiani, Ferruccio; Drocco, Maurizio; Sciacca, Eva; Spinella, Salvatore; Torquati, Massimo; Troina, Angelo
2014-01-01
The paper arguments are on enabling methodologies for the design of a fully parallel, online, interactive tool aiming to support the bioinformatics scientists .In particular, the features of these methodologies, supported by the FastFlow parallel programming framework, are shown on a simulation tool to perform the modeling, the tuning, and the sensitivity analysis of stochastic biological models. A stochastic simulation needs thousands of independent simulation trajectories turning into big data that should be analysed by statistic and data mining tools. In the considered approach the two stages are pipelined in such a way that the simulation stage streams out the partial results of all simulation trajectories to the analysis stage that immediately produces a partial result. The simulation-analysis workflow is validated for performance and effectiveness of the online analysis in capturing biological systems behavior on a multicore platform and representative proof-of-concept biological systems. The exploited methodologies include pattern-based parallel programming and data streaming that provide key features to the software designers such as performance portability and efficient in-memory (big) data management and movement. Two paradigmatic classes of biological systems exhibiting multistable and oscillatory behavior are used as a testbed.
Economic and outcomes consequences of TachoSil®: a systematic review.
Colombo, Giorgio L; Bettoni, Daria; Di Matteo, Sergio; Grumi, Camilla; Molon, Cinzia; Spinelli, Daniela; Mauro, Gaetano; Tarozzo, Alessia; Bruno, Giacomo M
2014-01-01
TachoSil(®) is a medicated sponge coated with human fibrinogen and human thrombin. It is indicated as a support treatment in adult surgery to improve hemostasis, promote tissue sealing, and support sutures when standard surgical techniques are insufficient. This review systematically analyses the international scientific literature relating to the use of TachoSil in hemostasis and as a surgical sealant, from the point of view of its economic impact. We carried out a systematic review of the PubMed literature up to November 2013. Based on the selection criteria, papers were grouped according to the following outcomes: reduction of time to hemostasis; decrease in length of hospital stay; and decrease in postoperative complications. Twenty-four scientific papers were screened, 13 (54%) of which were randomized controlled trials and included a total of 2,116 patients, 1,055 of whom were treated with TachoSil. In the clinical studies carried out in patients undergoing hepatic, cardiac, or renal surgery, the time to hemostasis obtained with TachoSil was lower (1-4 minutes) than the time measured with other techniques and hemostatic drugs, with statistically significant differences. Moreover, in 13 of 15 studies, TachoSil showed a statistically significant reduction in postoperative complications in comparison with the standard surgical procedure. The range of the observed decrease in the length of hospital stay for TachoSil patients was 2.01-3.58 days versus standard techniques, with a statistically significant difference in favor of TachoSil in eight of 15 studies. This analysis shows that TachoSil has a role as a supportive treatment in surgery to improve hemostasis and promote tissue sealing when standard techniques are insufficient, with a consequent decrease in postoperative complications and hospital costs.
Systematic review of wireless phone use and brain cancer and other head tumors.
Repacholi, Michael H; Lerchl, Alexander; Röösli, Martin; Sienkiewicz, Zenon; Auvinen, Anssi; Breckenkamp, Jürgen; d'Inzeo, Guglielmo; Elliott, Paul; Frei, Patrizia; Heinrich, Sabine; Lagroye, Isabelle; Lahkola, Anna; McCormick, David L; Thomas, Silke; Vecchia, Paolo
2012-04-01
We conducted a systematic review of scientific studies to evaluate whether the use of wireless phones is linked to an increased incidence of the brain cancer glioma or other tumors of the head (meningioma, acoustic neuroma, and parotid gland), originating in the areas of the head that most absorb radiofrequency (RF) energy from wireless phones. Epidemiology and in vivo studies were evaluated according to an agreed protocol; quality criteria were used to evaluate the studies for narrative synthesis but not for meta-analyses or pooling of results. The epidemiology study results were heterogeneous, with sparse data on long-term use (≥ 10 years). Meta-analyses of the epidemiology studies showed no statistically significant increase in risk (defined as P < 0.05) for adult brain cancer or other head tumors from wireless phone use. Analyses of the in vivo oncogenicity, tumor promotion, and genotoxicity studies also showed no statistically significant relationship between exposure to RF fields and genotoxic damage to brain cells, or the incidence of brain cancers or other tumors of the head. Assessment of the review results using the Hill criteria did not support a causal relationship between wireless phone use and the incidence of adult cancers in the areas of the head that most absorb RF energy from the use of wireless phones. There are insufficient data to make any determinations about longer-term use (≥ 10 years). © 2011 Wiley Periodicals, Inc.
Community pharmacists' attitudes and opinions towards supplying clozapine.
Gan, Yuh-Lin; O'Reilly, Claire L
2018-06-23
Background Clozapine is very effective for treatment-resistant schizophrenia, but its use has been limited due to the risk of agranulocytosis. From July 2015, clozapine has been accessible from Australian community pharmacies following regulatory changes, but pharmacists' attitudes towards these changes remain unknown. Objective To explore pharmacists' perspectives and experiences in supplying clozapine. Setting Australian community pharmacists. Methods A cross-sectional study with a mixed methods approach involving two phases. An online survey containing Likert-type and open-response questions was distributed to community pharmacists (n = 134) via ClopineCentral™ (clozapine monitoring system). Participants were then invited to participate in semi-structured telephone interviews (n = 12) regarding clozapine supply. Quantitative data were statistically analysed, while qualitative responses were thematically content-analysed. Main outcome measures Pharmacists' responses to surveys and interviews. Results Community pharmacists were supportive towards supplying clozapine as it increased access for consumers. Better patient-pharmacist relationships and holistic care approach were identified to benefit both consumers and pharmacists. Pharmacists reported to be confident (89.6%), have adequate support (73.1%), knowledge (86.6%) and skills (93.3%) in dispensing clozapine. Training and support received facilitated pharmacists' roles, whereas administrative issues, especially in obtaining valid haematology results, posed challenges. Educational and technical improvements were suggested to improve service provision. Conclusion Community pharmacists welcomed the regulatory changes positively and were confident in supporting consumers taking clozapine. Despite challenges present, benefits and facilitators identified supported the feasibility of this service in community pharmacies. Future research should explore other aspects of clozapine supply, such as attitudes of other stakeholders, to improve current supply systems.
Maslow and the motivation hierarchy: measuring satisfaction of the needs.
Taormina, Robert J; Gao, Jennifer H
2013-01-01
For each of the 5 needs in Maslow's motivational hierarchy (physiological, safety-security, belongingness, esteem, and self-actualization), operational definitions were developed from Maslow's theory of motivation. New measures were created based on the operational definitions (1) to assess the satisfaction of each need, (2) to assess their expected correlations (a) with each of the other needs and (b) with four social and personality measures (i.e., family support, traditional values, anxiety/worry, and life satisfaction), and (3) to test the ability of the satisfaction level of each need to statistically predict the satisfaction level of the next higher-level need. Psychometric tests of the scales conducted on questionnaire results from 386 adult respondents from the general population lent strong support for the validity and reliability of all 5 needs measures. Significant positive correlations among the scales were also found; that is, the more each lower-level need was satisfied, the more the next higher-level need was satisfied. Additionally, as predicted, family support, traditional values, and life satisfaction had significant positive correlations with the satisfaction of all 5 needs, and the anxiety/worry facet of neuroticism had significant negative correlations with the satisfaction of all the needs. Multiple regression analyses revealed that the satisfaction of each higher-level need was statistically predicted by the satisfaction of the need immediately below it in the hierarchy, as expected from Maslow's theory.
NASA Technical Reports Server (NTRS)
Malila, W. A.; Cicone, R. C.; Gleason, J. M.
1976-01-01
Simulated scanner system data values generated in support of LACIE (Large Area Crop Inventory Experiment) research and development efforts are presented. Synthetic inband (LANDSAT) wheat radiances and radiance components were computed and are presented for various wheat canopy and atmospheric conditions and scanner view geometries. Values include: (1) inband bidirectional reflectances for seven stages of wheat crop growth; (2) inband atmospheric features; and (3) inband radiances corresponding to the various combinations of wheat canopy and atmospheric conditions. Analyses of these data values are presented in the main report.
Nieuwenhuys, Angela; Papageorgiou, Eirini; Desloovere, Kaat; Molenaers, Guy; De Laet, Tinne
2017-01-01
Experts recently identified 49 joint motion patterns in children with cerebral palsy during a Delphi consensus study. Pattern definitions were therefore the result of subjective expert opinion. The present study aims to provide objective, quantitative data supporting the identification of these consensus-based patterns. To do so, statistical parametric mapping was used to compare the mean kinematic waveforms of 154 trials of typically developing children (n = 56) to the mean kinematic waveforms of 1719 trials of children with cerebral palsy (n = 356), which were classified following the classification rules of the Delphi study. Three hypotheses stated that: (a) joint motion patterns with 'no or minor gait deviations' (n = 11 patterns) do not differ significantly from the gait pattern of typically developing children; (b) all other pathological joint motion patterns (n = 38 patterns) differ from typically developing gait and the locations of difference within the gait cycle, highlighted by statistical parametric mapping, concur with the consensus-based classification rules. (c) all joint motion patterns at the level of each joint (n = 49 patterns) differ from each other during at least one phase of the gait cycle. Results showed that: (a) ten patterns with 'no or minor gait deviations' differed somewhat unexpectedly from typically developing gait, but these differences were generally small (≤3°); (b) all other joint motion patterns (n = 38) differed from typically developing gait and the significant locations within the gait cycle that were indicated by the statistical analyses, coincided well with the classification rules; (c) joint motion patterns at the level of each joint significantly differed from each other, apart from two sagittal plane pelvic patterns. In addition to these results, for several joints, statistical analyses indicated other significant areas during the gait cycle that were not included in the pattern definitions of the consensus study. Based on these findings, suggestions to improve pattern definitions were made.
Papageorgiou, Eirini; Desloovere, Kaat; Molenaers, Guy; De Laet, Tinne
2017-01-01
Experts recently identified 49 joint motion patterns in children with cerebral palsy during a Delphi consensus study. Pattern definitions were therefore the result of subjective expert opinion. The present study aims to provide objective, quantitative data supporting the identification of these consensus-based patterns. To do so, statistical parametric mapping was used to compare the mean kinematic waveforms of 154 trials of typically developing children (n = 56) to the mean kinematic waveforms of 1719 trials of children with cerebral palsy (n = 356), which were classified following the classification rules of the Delphi study. Three hypotheses stated that: (a) joint motion patterns with ‘no or minor gait deviations’ (n = 11 patterns) do not differ significantly from the gait pattern of typically developing children; (b) all other pathological joint motion patterns (n = 38 patterns) differ from typically developing gait and the locations of difference within the gait cycle, highlighted by statistical parametric mapping, concur with the consensus-based classification rules. (c) all joint motion patterns at the level of each joint (n = 49 patterns) differ from each other during at least one phase of the gait cycle. Results showed that: (a) ten patterns with ‘no or minor gait deviations’ differed somewhat unexpectedly from typically developing gait, but these differences were generally small (≤3°); (b) all other joint motion patterns (n = 38) differed from typically developing gait and the significant locations within the gait cycle that were indicated by the statistical analyses, coincided well with the classification rules; (c) joint motion patterns at the level of each joint significantly differed from each other, apart from two sagittal plane pelvic patterns. In addition to these results, for several joints, statistical analyses indicated other significant areas during the gait cycle that were not included in the pattern definitions of the consensus study. Based on these findings, suggestions to improve pattern definitions were made. PMID:28081229
NASA Astrophysics Data System (ADS)
Bierstedt, Svenja E.; Hünicke, Birgit; Zorita, Eduardo; Ludwig, Juliane
2017-07-01
We statistically analyse the relationship between the structure of migrating dunes in the southern Baltic and the driving wind conditions over the past 26 years, with the long-term aim of using migrating dunes as a proxy for past wind conditions at an interannual resolution. The present analysis is based on the dune record derived from geo-radar measurements by Ludwig et al. (2017). The dune system is located at the Baltic Sea coast of Poland and is migrating from west to east along the coast. The dunes present layers with different thicknesses that can be assigned to absolute dates at interannual timescales and put in relation to seasonal wind conditions. To statistically analyse this record and calibrate it as a wind proxy, we used a gridded regional meteorological reanalysis data set (coastDat2) covering recent decades. The identified link between the dune annual layers and wind conditions was additionally supported by the co-variability between dune layers and observed sea level variations in the southern Baltic Sea. We include precipitation and temperature into our analysis, in addition to wind, to learn more about the dependency between these three atmospheric factors and their common influence on the dune system. We set up a statistical linear model based on the correlation between the frequency of days with specific wind conditions in a given season and dune migration velocities derived for that season. To some extent, the dune records can be seen as analogous to tree-ring width records, and hence we use a proxy validation method usually applied in dendrochronology, cross-validation with the leave-one-out method, when the observational record is short. The revealed correlations between the wind record from the reanalysis and the wind record derived from the dune structure is in the range between 0.28 and 0.63, yielding similar statistical validation skill as dendroclimatological records.
Research of Extension of the Life Cycle of Helicopter Rotor Blade in Hungary
2003-02-01
Radiography (DXR), and (iii) Vibration Diagnostics (VD) with Statistical Energy Analysis (SEA) were semi- simultaneously applied [1]. The used three...2.2. Vibration Diagnostics (VD)) Parallel to the NDT measurements the Statistical Energy Analysis (SEA) as a vibration diagnostical tool were...noises were analysed with a dual-channel real time frequency analyser (BK2035). In addition to the Statistical Energy Analysis measurement a small
Hamel, Jean-Francois; Saulnier, Patrick; Pe, Madeline; Zikos, Efstathios; Musoro, Jammbe; Coens, Corneel; Bottomley, Andrew
2017-09-01
Over the last decades, Health-related Quality of Life (HRQoL) end-points have become an important outcome of the randomised controlled trials (RCTs). HRQoL methodology in RCTs has improved following international consensus recommendations. However, no international recommendations exist concerning the statistical analysis of such data. The aim of our study was to identify and characterise the quality of the statistical methods commonly used for analysing HRQoL data in cancer RCTs. Building on our recently published systematic review, we analysed a total of 33 published RCTs studying the HRQoL methods reported in RCTs since 1991. We focussed on the ability of the methods to deal with the three major problems commonly encountered when analysing HRQoL data: their multidimensional and longitudinal structure and the commonly high rate of missing data. All studies reported HRQoL being assessed repeatedly over time for a period ranging from 2 to 36 months. Missing data were common, with compliance rates ranging from 45% to 90%. From the 33 studies considered, 12 different statistical methods were identified. Twenty-nine studies analysed each of the questionnaire sub-dimensions without type I error adjustment. Thirteen studies repeated the HRQoL analysis at each assessment time again without type I error adjustment. Only 8 studies used methods suitable for repeated measurements. Our findings show a lack of consistency in statistical methods for analysing HRQoL data. Problems related to multiple comparisons were rarely considered leading to a high risk of false positive results. It is therefore critical that international recommendations for improving such statistical practices are developed. Copyright © 2017. Published by Elsevier Ltd.
Sunspot activity and influenza pandemics: a statistical assessment of the purported association.
Towers, S
2017-10-01
Since 1978, a series of papers in the literature have claimed to find a significant association between sunspot activity and the timing of influenza pandemics. This paper examines these analyses, and attempts to recreate the three most recent statistical analyses by Ertel (1994), Tapping et al. (2001), and Yeung (2006), which all have purported to find a significant relationship between sunspot numbers and pandemic influenza. As will be discussed, each analysis had errors in the data. In addition, in each analysis arbitrary selections or assumptions were also made, and the authors did not assess the robustness of their analyses to changes in those arbitrary assumptions. Varying the arbitrary assumptions to other, equally valid, assumptions negates the claims of significance. Indeed, an arbitrary selection made in one of the analyses appears to have resulted in almost maximal apparent significance; changing it only slightly yields a null result. This analysis applies statistically rigorous methodology to examine the purported sunspot/pandemic link, using more statistically powerful un-binned analysis methods, rather than relying on arbitrarily binned data. The analyses are repeated using both the Wolf and Group sunspot numbers. In all cases, no statistically significant evidence of any association was found. However, while the focus in this particular analysis was on the purported relationship of influenza pandemics to sunspot activity, the faults found in the past analyses are common pitfalls; inattention to analysis reproducibility and robustness assessment are common problems in the sciences, that are unfortunately not noted often enough in review.
NASA Astrophysics Data System (ADS)
Hendikawati, P.; Dewi, N. R.
2017-04-01
Statistics needed for use in the data analysis process and had a comprehensive implementation in daily life so that students must master the well statistical material. The use of Statistics textbook support with ICT and portfolio assessment approach was expected to help the students to improve mathematical connection skills. The subject of this research was 30 student teachers who take Statistics courses. The results of this research are the use of Statistics textbook support with ICT and portfolio assessment approach can improve students mathematical connection skills.
Keywords and Co-Occurrence Patterns in the Voynich Manuscript: An Information-Theoretic Analysis
Montemurro, Marcelo A.; Zanette, Damián H.
2013-01-01
The Voynich manuscript has remained so far as a mystery for linguists and cryptologists. While the text written on medieval parchment -using an unknown script system- shows basic statistical patterns that bear resemblance to those from real languages, there are features that suggested to some researches that the manuscript was a forgery intended as a hoax. Here we analyse the long-range structure of the manuscript using methods from information theory. We show that the Voynich manuscript presents a complex organization in the distribution of words that is compatible with those found in real language sequences. We are also able to extract some of the most significant semantic word-networks in the text. These results together with some previously known statistical features of the Voynich manuscript, give support to the presence of a genuine message inside the book. PMID:23805215
[Cause of death: from primary disease to direct cause of death].
Oppewal, F; Smedts, F M M; Meyboom-de Jong, B
2005-07-23
Following the death of a patient, the treating physician in the Netherlands is required to fill out two forms. Form A, which is the certificate of death and Form B, which is used by the Statistics Netherlands to compile data on causes ofdeath. The latter form often poses difficulty for the physician with respect to the primary cause of death. This applies particularly to cases of sudden death, which account for one third of all deaths in the Netherlands. As a result, the statistical analyses appear to lead to an incorrect representation of the distribution of causes of death. A more thorough investigation into the primary cause of death is desirable, if necessary, supported by a request for an autopsy. The primary cause of death is to be regarded as the basic disease from which the cascade of changes ultimately leading to death originated.
NASA Astrophysics Data System (ADS)
Renne, Paul R.; Fulford, Madeleine M.; Busby-Spera, Cathy
1991-03-01
Laser probe 40Ar/39Ar analyses of individual sanidine grains from four tuffs in the alluvial Late Cretaceous (Campanian) El Gallo Formation yield statistically distinct mean dates ranging from 74.87±0.05 Ma to 73.59±0.09 Ma. The exceptional precision of these dates permits calculation of statistically significant sediment accumulation rates that are much higher than passive sediment loading would cause, implying rapid tectonically induced subsidence. The dates bracket tightly the age of important dinosaur and mammalian faunas previously reported from the El Gallo Formation. The dates support an age less than 73 Ma for the Campanian/Maastrichtian stage boundary, younger than indicated by several currently used time scales. Further application of the single grain 40Ar/39Ar technique may be expected to greatly benefit stratigraphic studies of Mesozoic sedimentary basins and contribute to calibration of biostratigraphic and magnetostratigraphic time scales.
An Overview of R in Health Decision Sciences.
Jalal, Hawre; Pechlivanoglou, Petros; Krijkamp, Eline; Alarid-Escudero, Fernando; Enns, Eva; Hunink, M G Myriam
2017-10-01
As the complexity of health decision science applications increases, high-level programming languages are increasingly adopted for statistical analyses and numerical computations. These programming languages facilitate sophisticated modeling, model documentation, and analysis reproducibility. Among the high-level programming languages, the statistical programming framework R is gaining increased recognition. R is freely available, cross-platform compatible, and open source. A large community of users who have generated an extensive collection of well-documented packages and functions supports it. These functions facilitate applications of health decision science methodology as well as the visualization and communication of results. Although R's popularity is increasing among health decision scientists, methodological extensions of R in the field of decision analysis remain isolated. The purpose of this article is to provide an overview of existing R functionality that is applicable to the various stages of decision analysis, including model design, input parameter estimation, and analysis of model outputs.
A culture conducive to women's academic success: development of a measure.
Westring, Alyssa Friede; Speck, Rebecca M; Sammel, Mary Dupuis; Scott, Patricia; Tuton, Lucy Wolf; Grisso, Jeane Ann; Abbuhl, Stephanie
2012-11-01
The work environment culture inhibits women's career success in academic medicine. The lack of clarity and consistency in the definition, measurement, and analysis of culture constrains current research on the topic. The authors addressed this gap by defining the construct of a culture conducive to women's academic success (CCWAS) and creating a measure (i.e., tool) to evaluate it. First, the authors conducted a review of published literature, held focus groups, and consulted with subject matter experts to develop a measure of academic workplace culture for women. Then they developed and pilot-tested the measure with a convenience sample of women assistant professors. After refining the measure, they administered it, along with additional scales for validation, to 133 women assistant professors at the University of Pennsylvania. Finally, they conducted statistical analyses to explore the measure's nature and validity. A CCWAS consists of four distinct, but related, dimensions: equal access, work-life balance, freedom from gender biases, and supportive leadership. The authors found evidence that women within departments/divisions agree on the supportiveness of their units but that substantial differences among units exist. The analyses provided strong evidence for the reliability and validity of their measure. This report contributes to a growing understanding of women's academic medicine careers and provides a measure that researchers can use to assess the supportiveness of the culture for women assistant professors and that leaders can use to evaluate the effectiveness of interventions designed to increase the supportiveness of the environment for women faculty.
Abajo, María; Rodríguez-Sanz, Maica; Malmusi, Davide; Salvador, María; Borrell, Carme
2017-03-01
To explore the associations between social determinants, caregiver's network support, burden of care and their consequences in health and living conditions of informal caregivers. The socio-demographic trends regarding population ageing and changes in family models trigger an increased demand for care. Cross-sectional study based on the 2008 edition of the National Disability, Independence and Dependency Situations Survey (DIDSS-2008) conducted by the National Statistics Institute in Spain. Analyses focused on persons identified as primary caregivers who co-reside with the dependent person. The associations between social determinants of caregivers, burden of care, support network and problems attributed to informal care (impaired health, depression, professional, economic and personal issues) were estimated by fitting robust Poisson regression models. Analyses were conducted separately for women and men. The study sample included 6923 caregivers, 73% of women and 27% of men. Gender and socio-economic inequalities were found in assumption of responsibilities and burden of caring for dependents, which tend to fall more on women and persons of lower socio-economic level, who in turn have less access to formal support. These aspects translate into a higher prevalence of health, professional, economic and personal problems. The study highlights gender and socio-economic inequalities in informal caregiving and its negative consequences. These findings may be useful in the design of policies and support programmes targeting the most affected groups of informal caregivers. © 2016 John Wiley & Sons Ltd.
Al Chawa, Taofik; Ludwig, Kerstin U; Fier, Heide; Pötzsch, Bernd; Reich, Rudolf H; Schmidt, Gül; Braumann, Bert; Daratsianos, Nikolaos; Böhmer, Anne C; Schuencke, Hannah; Alblas, Margrieta; Fricker, Nadine; Hoffmann, Per; Knapp, Michael; Lange, Christoph; Nöthen, Markus M; Mangold, Elisabeth
2014-06-01
The genes Gremlin-1 (GREM1) and Noggin (NOG) are components of the bone morphogenetic protein 4 pathway, which has been implicated in craniofacial development. Both genes map to recently identified susceptibility loci (chromosomal region 15q13, 17q22) for nonsyndromic cleft lip with or without cleft palate (nsCL/P). The aim of the present study was to determine whether rare variants in either gene are implicated in nsCL/P etiology. The complete coding regions, untranslated regions, and splice sites of GREM1 and NOG were sequenced in 96 nsCL/P patients and 96 controls of Central European ethnicity. Three burden and four nonburden tests were performed. Statistically significant results were followed up in a second case-control sample (n = 96, respectively). For rare variants observed in cases, segregation analyses were performed. In NOG, four rare sequence variants (minor allele frequency < 1%) were identified. Here, burden and nonburden analyses generated nonsignificant results. In GREM1, 33 variants were identified, 15 of which were rare. Of these, five were novel. Significant p-values were generated in three nonburden analyses. Segregation analyses revealed incomplete penetrance for all variants investigated. Our study did not provide support for NOG being the causal gene at 17q22. However, the observation of a significant excess of rare variants in GREM1 supports the hypothesis that this is the causal gene at chr. 15q13. Because no single causal variant was identified, future sequencing analyses of GREM1 should involve larger samples and the investigation of regulatory elements. © 2014 Wiley Periodicals, Inc.
Does climate directly influence NPP globally?
Chu, Chengjin; Bartlett, Megan; Wang, Youshi; He, Fangliang; Weiner, Jacob; Chave, Jérôme; Sack, Lawren
2016-01-01
The need for rigorous analyses of climate impacts has never been more crucial. Current textbooks state that climate directly influences ecosystem annual net primary productivity (NPP), emphasizing the urgent need to monitor the impacts of climate change. A recent paper challenged this consensus, arguing, based on an analysis of NPP for 1247 woody plant communities across global climate gradients, that temperature and precipitation have negligible direct effects on NPP and only perhaps have indirect effects by constraining total stand biomass (Mtot ) and stand age (a). The authors of that study concluded that the length of the growing season (lgs ) might have a minor influence on NPP, an effect they considered not to be directly related to climate. In this article, we describe flaws that affected that study's conclusions and present novel analyses to disentangle the effects of stand variables and climate in determining NPP. We re-analyzed the same database to partition the direct and indirect effects of climate on NPP, using three approaches: maximum-likelihood model selection, independent-effects analysis, and structural equation modeling. These new analyses showed that about half of the global variation in NPP could be explained by Mtot combined with climate variables and supported strong and direct influences of climate independently of Mtot , both for NPP and for net biomass change averaged across the known lifetime of the stands (ABC = average biomass change). We show that lgs is an important climate variable, intrinsically correlated with, and contributing to mean annual temperature and precipitation (Tann and Pann ), all important climatic drivers of NPP. Our analyses provide guidance for statistical and mechanistic analyses of climate drivers of ecosystem processes for predictive modeling and provide novel evidence supporting the strong, direct role of climate in determining vegetation productivity at the global scale. © 2015 John Wiley & Sons Ltd.
Using basic statistics on the individual patient's own numeric data.
Hart, John
2012-12-01
This theoretical report gives an example for how coefficient of variation (CV) and quartile analysis (QA) to assess outliers might be able to be used to analyze numeric data in practice for an individual patient. A patient was examined for 8 visits using infrared instrumentation for measurement of mastoid fossa temperature differential (MFTD) readings. The CV and QA were applied to the readings. The participant also completed the Short Form-12 health perception survey on each visit, and these findings were correlated with CV to determine if CV had outcomes support (clinical significance). An outlier MFTD reading was observed on the eighth visit according to QA that coincided with the largest CV value for the MFTDs. Correlations between the Short Form-12 and CV were low to negligible, positive, and statistically nonsignificant. This case provides an example of how basic statistical analyses could possibly be applied to numerical data in chiropractic practice for an individual patient. This might add objectivity to analyzing an individual patient's data in practice, particularly if clinical significance of a clinical numerical finding is unknown.
NASA DOE POD NDE Capabilities Data Book
NASA Technical Reports Server (NTRS)
Generazio, Edward R.
2015-01-01
This data book contains the Directed Design of Experiments for Validating Probability of Detection (POD) Capability of NDE Systems (DOEPOD) analyses of the nondestructive inspection data presented in the NTIAC, Nondestructive Evaluation (NDE) Capabilities Data Book, 3rd ed., NTIAC DB-97-02. DOEPOD is designed as a decision support system to validate inspection system, personnel, and protocol demonstrating 0.90 POD with 95% confidence at critical flaw sizes, a90/95. The test methodology used in DOEPOD is based on the field of statistical sequential analysis founded by Abraham Wald. Sequential analysis is a method of statistical inference whose characteristic feature is that the number of observations required by the procedure is not determined in advance of the experiment. The decision to terminate the experiment depends, at each stage, on the results of the observations previously made. A merit of the sequential method, as applied to testing statistical hypotheses, is that test procedures can be constructed which require, on average, a substantially smaller number of observations than equally reliable test procedures based on a predetermined number of observations.
Impact of performance-based financing on primary health care services in Haiti.
Zeng, Wu; Cros, Marion; Wright, Katherine D; Shepard, Donald S
2013-09-01
To strengthen Haiti's primary health care (PHC) system, the country first piloted performance-based financing (PBF) in 1999 and subsequently expanded the approach to most internationally funded non-government organizations. PBF complements support (training and technical assistance). This study evaluates (a) the separate impact of PBF and international support on PHC's service delivery; (b) the combined impact of PBF and technical assistance on PHC's service delivery; and (c) the costs of PBF implementation in Haiti. To minimize the risk of facilities neglecting potential non-incentivized services, the incentivized indicators were randomly chosen at the end of each year. We obtained quantities of key services from four departments for 217 health centres (15 with PBF and 202 without) from 2008 through 2010, computed quarterly growth rates and analysed the results using a difference-in-differences approach by comparing the growth of incentivized and non-incentivized services between PBF and non-PBF facilities. To interpret the statistical analyses, we also interviewed staff in four facilities. Whereas international support added 39% to base costs of PHC, incentive payments added only 6%. Support alone increased the quantities of PHC services over 3 years by 35% (2.7%/quarter). However, support plus incentives increased these amounts by 87% over 3 years (5.7%/quarter) compared with facilities with neither input. Incentives alone was associated with a net 39% increase over this period, and more than doubled the growth of services (P < 0.05). Interview findings found no adverse impacts and, in fact, indicated beneficial impacts on quality. Incentives proved to be a relatively inexpensive, well accepted and very effective complement to support, suggesting that a small amount of money, strategically used, can substantially improve PHC. Haiti's experience, after more than a decade of use, indicates that incentives are an effective tool to strengthen PHC.
NASA Astrophysics Data System (ADS)
Lanfredi, M.; Simoniello, T.; Cuomo, V.; Macchiato, M.
2009-02-01
This study originated from recent results reported in literature, which support the existence of long-range (power-law) persistence in atmospheric temperature fluctuations on monthly and inter-annual scales. We investigated the results of Detrended Fluctuation Analysis (DFA) carried out on twenty-two historical daily time series recorded in Europe in order to evaluate the reliability of such findings in depth. More detailed inspections emphasized systematic deviations from power-law and high statistical confidence for functional form misspecification. Rigorous analyses did not support scale-free correlation as an operative concept for Climate modelling, as instead suggested in literature. In order to understand the physical implications of our results better, we designed a bivariate Markov process, parameterised on the basis of the atmospheric observational data by introducing a slow dummy variable. The time series generated by this model, analysed both in time and frequency domains, tallied with the real ones very well. They accounted for both the deceptive scaling found in literature and the correlation details enhanced by our analysis. Our results seem to evidence the presence of slow fluctuations from another climatic sub-system such as ocean, which inflates temperature variance up to several months. They advise more precise re-analyses of temperature time series before suggesting dynamical paradigms useful for Climate modelling and for the assessment of Climate Change.
NASA Astrophysics Data System (ADS)
Lanfredi, M.; Simoniello, T.; Cuomo, V.; Macchiato, M.
2009-07-01
This study originated from recent results reported in literature, which support the existence of long-range (power-law) persistence in atmospheric temperature fluctuations on monthly and inter-annual scales. We investigated the results of Detrended Fluctuation Analysis (DFA) carried out on twenty-two historical daily time series recorded in Europe in order to evaluate the reliability of such findings in depth. More detailed inspections emphasized systematic deviations from power-law and high statistical confidence for functional form misspecification. Rigorous analyses did not support scale-free correlation as an operative concept for Climate modelling, as instead suggested in literature. In order to understand the physical implications of our results better, we designed a bivariate Markov process, parameterised on the basis of the atmospheric observational data by introducing a slow dummy variable. The time series generated by this model, analysed both in time and frequency domains, tallied with the real ones very well. They accounted for both the deceptive scaling found in literature and the correlation details enhanced by our analysis. Our results seem to evidence the presence of slow fluctuations from another climatic sub-system such as ocean, which inflates temperature variance up to several months. They advise more precise re-analyses of temperature time series before suggesting dynamical paradigms useful for Climate modelling and for the assessment of Climate Change.
Meta-analysis of thirty-two case-control and two ecological radon studies of lung cancer.
Dobrzynski, Ludwik; Fornalski, Krzysztof W; Reszczynska, Joanna
2018-03-01
A re-analysis has been carried out of thirty-two case-control and two ecological studies concerning the influence of radon, a radioactive gas, on the risk of lung cancer. Three mathematically simplest dose-response relationships (models) were tested: constant (zero health effect), linear, and parabolic (linear-quadratic). Health effect end-points reported in the analysed studies are odds ratios or relative risk ratios, related either to morbidity or mortality. In our preliminary analysis, we show that the results of dose-response fitting are qualitatively (within uncertainties, given as error bars) the same, whichever of these health effect end-points are applied. Therefore, we deemed it reasonable to aggregate all response data into the so-called Relative Health Factor and jointly analysed such mixed data, to obtain better statistical power. In the second part of our analysis, robust Bayesian and classical methods of analysis were applied to this combined dataset. In this part of our analysis, we selected different subranges of radon concentrations. In view of substantial differences between the methodology used by the authors of case-control and ecological studies, the mathematical relationships (models) were applied mainly to the thirty-two case-control studies. The degree to which the two ecological studies, analysed separately, affect the overall results when combined with the thirty-two case-control studies, has also been evaluated. In all, as a result of our meta-analysis of the combined cohort, we conclude that the analysed data concerning radon concentrations below ~1000 Bq/m3 (~20 mSv/year of effective dose to the whole body) do not support the thesis that radon may be a cause of any statistically significant increase in lung cancer incidence.
NASA Astrophysics Data System (ADS)
Farrell, S. L.; Kurtz, N. T.; Richter-Menge, J.; Harbeck, J. P.; Onana, V.
2012-12-01
Satellite-derived estimates of ice thickness and observations of ice extent over the last decade point to a downward trend in the basin-scale ice volume of the Arctic Ocean. This loss has broad-ranging impacts on the regional climate and ecosystems, as well as implications for regional infrastructure, marine navigation, national security, and resource exploration. New observational datasets at small spatial and temporal scales are now required to improve our understanding of physical processes occurring within the ice pack and advance parameterizations in the next generation of numerical sea-ice models. High-resolution airborne and satellite observations of the sea ice are now available at meter-scale resolution or better that provide new details on the properties and morphology of the ice pack across basin scales. For example the NASA IceBridge airborne campaign routinely surveys the sea ice of the Arctic and Southern Oceans with an advanced sensor suite including laser and radar altimeters and digital cameras that together provide high-resolution measurements of sea ice freeboard, thickness, snow depth and lead distribution. Here we present statistical analyses of the ice pack primarily derived from the following IceBridge instruments: the Digital Mapping System (DMS), a nadir-looking, high-resolution digital camera; the Airborne Topographic Mapper, a scanning lidar; and the University of Kansas snow radar, a novel instrument designed to estimate snow depth on sea ice. Together these instruments provide data from which a wide range of sea ice properties may be derived. We provide statistics on lead distribution and spacing, lead width and area, floe size and distance between floes, as well as ridge height, frequency and distribution. The goals of this study are to (i) identify unique statistics that can be used to describe the characteristics of specific ice regions, for example first-year/multi-year ice, diffuse ice edge/consolidated ice pack, and convergent/divergent ice zones, (ii) provide datasets that support enhanced parameterizations in numerical models as well as model initialization and validation, (iii) parameters of interest to Arctic stakeholders for marine navigation and ice engineering studies, and (iv) statistics that support algorithm development for the next-generation of airborne and satellite altimeters, including NASA's ICESat-2 mission. We describe the potential contribution our results can make towards the improvement of coupled ice-ocean numerical models, and discuss how data synthesis and integration with high-resolution models may improve our understanding of sea ice variability and our capabilities in predicting the future state of the ice pack.
Jin, Zhichao; Yu, Danghui; Zhang, Luoman; Meng, Hong; Lu, Jian; Gao, Qingbin; Cao, Yang; Ma, Xiuqiang; Wu, Cheng; He, Qian; Wang, Rui; He, Jia
2010-01-01
Background High quality clinical research not only requires advanced professional knowledge, but also needs sound study design and correct statistical analyses. The number of clinical research articles published in Chinese medical journals has increased immensely in the past decade, but study design quality and statistical analyses have remained suboptimal. The aim of this investigation was to gather evidence on the quality of study design and statistical analyses in clinical researches conducted in China for the first decade of the new millennium. Methodology/Principal Findings Ten (10) leading Chinese medical journals were selected and all original articles published in 1998 (N = 1,335) and 2008 (N = 1,578) were thoroughly categorized and reviewed. A well-defined and validated checklist on study design, statistical analyses, results presentation, and interpretation was used for review and evaluation. Main outcomes were the frequencies of different types of study design, error/defect proportion in design and statistical analyses, and implementation of CONSORT in randomized clinical trials. From 1998 to 2008: The error/defect proportion in statistical analyses decreased significantly ( = 12.03, p<0.001), 59.8% (545/1,335) in 1998 compared to 52.2% (664/1,578) in 2008. The overall error/defect proportion of study design also decreased ( = 21.22, p<0.001), 50.9% (680/1,335) compared to 42.40% (669/1,578). In 2008, design with randomized clinical trials remained low in single digit (3.8%, 60/1,578) with two-third showed poor results reporting (defects in 44 papers, 73.3%). Nearly half of the published studies were retrospective in nature, 49.3% (658/1,335) in 1998 compared to 48.2% (761/1,578) in 2008. Decreases in defect proportions were observed in both results presentation ( = 93.26, p<0.001), 92.7% (945/1,019) compared to 78.2% (1023/1,309) and interpretation ( = 27.26, p<0.001), 9.7% (99/1,019) compared to 4.3% (56/1,309), some serious ones persisted. Conclusions/Significance Chinese medical research seems to have made significant progress regarding statistical analyses, but there remains ample room for improvement regarding study designs. Retrospective clinical studies are the most often used design, whereas randomized clinical trials are rare and often show methodological weaknesses. Urgent implementation of the CONSORT statement is imperative. PMID:20520824
Use of Statistical Analyses in the Ophthalmic Literature
Lisboa, Renato; Meira-Freitas, Daniel; Tatham, Andrew J.; Marvasti, Amir H.; Sharpsten, Lucie; Medeiros, Felipe A.
2014-01-01
Purpose To identify the most commonly used statistical analyses in the ophthalmic literature and to determine the likely gain in comprehension of the literature that readers could expect if they were to sequentially add knowledge of more advanced techniques to their statistical repertoire. Design Cross-sectional study Methods All articles published from January 2012 to December 2012 in Ophthalmology, American Journal of Ophthalmology and Archives of Ophthalmology were reviewed. A total of 780 peer-reviewed articles were included. Two reviewers examined each article and assigned categories to each one depending on the type of statistical analyses used. Discrepancies between reviewers were resolved by consensus. Main Outcome Measures Total number and percentage of articles containing each category of statistical analysis were obtained. Additionally we estimated the accumulated number and percentage of articles that a reader would be expected to be able to interpret depending on their statistical repertoire. Results Readers with little or no statistical knowledge would be expected to be able to interpret the statistical methods presented in only 20.8% of articles. In order to understand more than half (51.4%) of the articles published, readers were expected to be familiar with at least 15 different statistical methods. Knowledge of 21 categories of statistical methods was necessary to comprehend 70.9% of articles, while knowledge of more than 29 categories was necessary to comprehend more than 90% of articles. Articles in retina and glaucoma subspecialties showed a tendency for using more complex analysis when compared to cornea. Conclusions Readers of clinical journals in ophthalmology need to have substantial knowledge of statistical methodology to understand the results of published studies in the literature. The frequency of use of complex statistical analyses also indicates that those involved in the editorial peer-review process must have sound statistical knowledge in order to critically appraise articles submitted for publication. The results of this study could provide guidance to direct the statistical learning of clinical ophthalmologists, researchers and educators involved in the design of courses for residents and medical students. PMID:24612977
Factors associated with frailty in chronically ill older adults.
Hackstaff, Lynn
2009-01-01
An ex post facto analysis of a secondary dataset examined relationships between physical frailty, depression, and the self-perceived domains of health status and quality-of-life in older adults. The randomized sample included 992 community-dwelling, chronically ill, and functionally impaired adults age 65 and older who received care from a Southern California Kaiser Permanente medical center between 1998 and 2002. Physical frailty represents a level of physiologic vulnerability and functional loss that results in dependence on others for basic, daily living needs (Fried et al., 2001). The purpose of the study was to identify possible intervention junctures related to self-efficacy of older adults in order to help optimize their functionality. Multivariate correlation analyses showed statistically significant positive correlations between frailty level and depression (r = .18; p = < .05), number of medical conditions (r = .09; p = < .05), and self-rated quality-of-life (r = .24; p = < .05). Frailty level showed a statistically significant negative correlation with self-perceived health status (r = -.25; p = < .05). Notably, no statistically significant correlation was found between age and frailty level (r = -.03; p = < .05). In linear regression, self-perceived health status had a partial variance with frailty level (part r = -.18). The significant correlations found support further research to identify interventions to help vulnerable, older adults challenge self-perceived capabilities so that they may achieve optimum functionality through increased physical activity earlier on, and increased self-efficacy to support successful adaptation to aging-related losses.
Global atmospheric circulation statistics, 1000-1 mb
NASA Technical Reports Server (NTRS)
Randel, William J.
1992-01-01
The atlas presents atmospheric general circulation statistics derived from twelve years (1979-90) of daily National Meteorological Center (NMC) operational geopotential height analyses; it is an update of a prior atlas using data over 1979-1986. These global analyses are available on pressure levels covering 1000-1 mb (approximately 0-50 km). The geopotential grids are a combined product of the Climate Analysis Center (which produces analyses over 70-1 mb) and operational NMC analyses (over 1000-100 mb). Balance horizontal winds and hydrostatic temperatures are derived from the geopotential fields.
Cheng, Richard K; Deng, Mario C; Tseng, Chi-hong; Shemin, Richard J; Kubak, Bernard M; MacLellan, W Robb
2012-08-01
Prior studies have identified risk factors for survival in patients with end-stage heart failure (HF) requiring left ventricular assist device (LVAD) support. However, patients with biventricular HF may represent a unique cohort. We retrospectively evaluated a consecutive cohort of 113 adult, end-stage HF patients at University of California Los Angeles Medical Center who required BIVAD support between 2000 and 2009. Survival to transplant was 66.4%, with 1-year actuarial survival of 62.8%. All patients were Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) Level 1 or 2 and received Thoratec (Pleasanton, CA) paracorporeal BIVAD as a bridge to transplant. Univariate analyses showed dialysis use, ventilator use, extracorporal membrane oxygenation use, low cardiac output, preserved LV ejection fraction (restrictive physiology), normal-to-high sodium, low platelet count, low total cholesterol, low high-density and high-density lipoprotein, low albumin, and elevated aspartate aminotransferase were associated with increased risk of death. We generated a scoring system for survival to transplant. Our final model, with age, sex, dialysis, cholesterol, ventilator, and albumin, gave a C-statistic of 0.870. A simplified system preserved a C-statistic of 0.844. Patients were divided into high-risk or highest-risk groups (median respective survival, 367 and 17 days), with strong discrimination between groups for death. We have generated a scoring system that offers high prognostic ability for patients requiring BIVAD support and hope that it may assist in clinical decision making. Further studies are needed to prospectively validate our scoring system. Copyright © 2012 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.
Miller, A; Pilcher, D; Mercaldo, N; Leong, T; Scheinkestel, C; Schildcrout, J
2010-08-01
Screen designs in computerized clinical information systems (CIS) have been modeled on their paper predecessors. However, limited understanding about how paper forms support clinical work means that we risk repeating old mistakes and creating new opportunities for error and inefficiency as illustrated by problems associated with computerized provider order entry systems. This study was designed to elucidate principles underlying a successful ICU paper-based CIS. The research was guided by two exploratory hypotheses: (1) paper-based artefacts (charts, notes, equipment, order forms) are used differently by nurses, doctors and other healthcare professionals in different (formal and informal) conversation contexts and (2) different artefacts support different decision processes that are distributed across role-based conversations. All conversations undertaken at the bedsides of five patients were recorded with any supporting artefacts for five days per patient. Data was coded according to conversational role-holders, clinical decision process, conversational context and artefacts. 2133 data points were analyzed using Poisson logistic regression analyses. Results show significant interactions between artefacts used during different professional conversations in different contexts (chi(2)((df=16))=55.8, p<0.0001). The interaction between artefacts used during different professional conversations for different clinical decision processes was not statistically significant although all two-way interactions were statistically significant. Paper-based CIS have evolved to support complex interdisciplinary decision processes. The translation of two design principles - support interdisciplinary perspectives and integrate decision processes - from paper to computerized CIS may minimize the risks associated with computerization. 2010 Australian College of Critical Care Nurses Ltd. Published by Elsevier Ltd. All rights reserved.
Ennen, J.R.; Kreiser, B.R.; Qualls, C.P.; Lovich, J.E.
2010-01-01
The turtle genus Graptemys consists of 15 recognized taxa, distinguished largely on the basis of pigmentation pattern (i.e., soft tissue and shell), head size, and shell morphology. However, phylogenetic studies have shown limited sequence divergence within the genus and between Graptemys oculifera and Graptemys flavimaculata relative to most other members of the Emydidae. Graptemys oculifera of the Pearl River drainage and G. flavimaculata of the Pascagoula River drainage have been recognized as species since 1890 and 1954, respectively. However, the description of G. flavimaculata was based on a limited number of morphological characters. Several of these characters overlap between G. flavimaculata and G. oculifera, and no attempt was made to test for significant morphological differentiation. In this study, we reevaluated the morphological and genetic distinctiveness of G. flavimaculata and G. oculifera with (1) multivariate statistical analyses of 44 morphological characters and (2) 1,560 bp of sequence data from two mitochondrial genes (control region and ND4). The morphological and molecular analyses produced incongruent results. The principal components analysis ordinations separated the two species along a pigmentation gradient with G. flavimaculata having more yellow pigmentation than G. oculifera. Likewise, clustering analyses separated the specimens into two distinct groups with little overlap between the species. Our mitochondrial data supported previous findings of limited genetic differentiation between the two species. However, the results of our morphological analyses, in conjunction with recently published nuclear gene sequence data, support the continued recognition of the two species. Copyright 2010 Society for the Study of Amphibians and Reptiles.
Myers, E A; Rodríguez-Robles, J A; Denardo, D F; Staub, R E; Stropoli, A; Ruane, S; Burbrink, F T
2013-11-01
Phylogeographic inference can determine the timing of population divergence, historical demographic processes, patterns of migration, and when extended to multiple species, the history of communities. Single-locus analyses can mislead interpretations of the evolutionary history of taxa and comparative analyses. It is therefore important to revisit previous single-locus phylogeographic studies, particularly those that have been used to propose general patterns for regional biotas and the processes responsible for generating inferred patterns. Here, we employ a multilocus statistical approach to re-examine the phylogeography of Lampropeltis zonata. Using nonparametic and Bayesian species delimitation, we determined that there are two well-supported species within L. zonata. Ecological niche modelling supports the delimitation of these taxa, suggesting that the two species inhabit distinct climatic environments. Gene flow between the two taxa is low and appears to occur unidirectionally. Further, our data suggest that gene flow was mediated by females, a rare pattern in snakes. In contrast to previous analyses, we determined that the divergence between the two lineages occurred in the late Pliocene (c. 2.07 Ma). Spatially and temporally, the divergence of these lineages is associated with the inundation of central California by the Monterey Bay. The effective population sizes of the two species appear to have been unaffected by Pleistocene glaciation. Our increased sampling of loci for L. zonata, combined with previously published multilocus analyses of other sympatric species, suggests that previous conclusions reached by comparative phylogeographic studies conducted within the California Floristic Province should be reassessed. © 2013 John Wiley & Sons Ltd.
O'Connor, Siobhan; Andrews, Tom
2016-01-01
Nurse educators are exploring different mobile technologies to provide additional support to nursing students in clinical practice. However, the view of nursing students on the use of smartphone applications (apps) to enhance clinical education has not been explored. This proposed study will use a self-reported questionnaire to examine the opinions of nursing students on the current and potential use of smartphone apps when training in clinical settings. Descriptive and inferential statistics will be performed on the quantitative data. Qualitative data from open ended questions will be thematically analysed using the framework approach. This will be the first study to examine the use of smartphone apps as a support in clinical teaching from a students' perspective. Their opinion is vital if the right mobile technology is to be designed and implemented.
Understanding older adults' usage of community green spaces in Taipei, Taiwan.
Pleson, Eryn; Nieuwendyk, Laura M; Lee, Karen K; Chaddah, Anuradha; Nykiforuk, Candace I J; Schopflocher, Donald
2014-01-27
As the world's population ages, there is an increasing need for community environments to support physical activity and social connections for older adults. This exploratory study sought to better understand older adults' usage and perceptions of community green spaces in Taipei, Taiwan, through direct observations of seven green spaces and nineteen structured interviews. Descriptive statistics from observations using the System for Observing Play and Recreation in Communities (SOPARC) confirm that older adults use Taipei's parks extensively. Our analyses of interviews support the following recommendations for age-friendly active living initiatives for older adults: make green spaces accessible to older adults; organize a variety of structured activities that appeal to older adults particularly in the morning; equip green spaces for age-appropriate physical activity; and, promote the health advantages of green spaces to older adults.
Children's knowledge of the earth: a new methodological and statistical approach.
Straatemeier, Marthe; van der Maas, Han L J; Jansen, Brenda R J
2008-08-01
In the field of children's knowledge of the earth, much debate has concerned the question of whether children's naive knowledge-that is, their knowledge before they acquire the standard scientific theory-is coherent (i.e., theory-like) or fragmented. We conducted two studies with large samples (N=328 and N=381) using a new paper-and-pencil test, denoted the EARTH (EArth Representation Test for cHildren), to discriminate between these two alternatives. We performed latent class analyses on the responses to the EARTH to test mental models associated with these alternatives. The naive mental models, as formulated by Vosniadou and Brewer, were not supported by the results. The results indicated that children's knowledge of the earth becomes more consistent as children grow older. These findings support the view that children's naive knowledge is fragmented.
Understanding Older Adults’ Usage of Community Green Spaces in Taipei, Taiwan
Pleson, Eryn; Nieuwendyk, Laura M.; Lee, Karen K.; Chaddah, Anuradha; Nykiforuk, Candace I. J.; Schopflocher, Donald
2014-01-01
As the world’s population ages, there is an increasing need for community environments to support physical activity and social connections for older adults. This exploratory study sought to better understand older adults’ usage and perceptions of community green spaces in Taipei, Taiwan, through direct observations of seven green spaces and nineteen structured interviews. Descriptive statistics from observations using the System for Observing Play and Recreation in Communities (SOPARC) confirm that older adults use Taipei’s parks extensively. Our analyses of interviews support the following recommendations for age-friendly active living initiatives for older adults: make green spaces accessible to older adults; organize a variety of structured activities that appeal to older adults particularly in the morning; equip green spaces for age-appropriate physical activity; and, promote the health advantages of green spaces to older adults. PMID:24473116
Development of the Statistical Reasoning in Biology Concept Inventory (SRBCI)
Deane, Thomas; Nomme, Kathy; Jeffery, Erica; Pollock, Carol; Birol, Gülnur
2016-01-01
We followed established best practices in concept inventory design and developed a 12-item inventory to assess student ability in statistical reasoning in biology (Statistical Reasoning in Biology Concept Inventory [SRBCI]). It is important to assess student thinking in this conceptual area, because it is a fundamental requirement of being statistically literate and associated skills are needed in almost all walks of life. Despite this, previous work shows that non–expert-like thinking in statistical reasoning is common, even after instruction. As science educators, our goal should be to move students along a novice-to-expert spectrum, which could be achieved with growing experience in statistical reasoning. We used item response theory analyses (the one-parameter Rasch model and associated analyses) to assess responses gathered from biology students in two populations at a large research university in Canada in order to test SRBCI’s robustness and sensitivity in capturing useful data relating to the students’ conceptual ability in statistical reasoning. Our analyses indicated that SRBCI is a unidimensional construct, with items that vary widely in difficulty and provide useful information about such student ability. SRBCI should be useful as a diagnostic tool in a variety of biology settings and as a means of measuring the success of teaching interventions designed to improve statistical reasoning skills. PMID:26903497
Fortin, Guillaume; Lecomte, Tania; Corbière, Marc
2017-06-01
When employment difficulties in people with severe mental illness (SMI) occur, it could be partly linked to issues not specific to SMI, such as personality traits or problems. Despite the fact that personality has a marked influence on almost every aspect of work behavior, it has scarcely been investigated in the context of employment for people with SMI. We aimed to evaluate if personality was more predictive than clinical variables of different competitive work outcomes, namely acquisition of competitive employment, delay to acquisition and job tenure. A sample of 82 people with a SMI enrolled in supported employment programs (SEP) was recruited and asked to complete various questionnaires and interviews. Statistical analyses included logistic regressions and survival analyses (Cox regressions). Prior employment, personality problems and negative symptoms are significantly related to acquisition of a competitive employment and to delay to acquisition whereas the conscientiousness personality trait was predictive of job tenure. Our results point out the relevance of personality traits and problems as predictors of work outcomes in people with SMI registered in SEP. Future studies should recruit larger samples and also investigate these links with other factors related to work outcomes.
2014-01-01
Background Mental health patients can feel anxious about losing the support of staff and patients when discharged from hospital and often discontinue treatment, experience relapse and readmission to hospital, and sometimes attempt suicide. The benefits of peer support in mental health services have been identified in a number of studies with some suggesting clinical and economic gains in patients being discharged. Methods This pilot randomised controlled trial with economic evaluation aimed to explore whether peer support in addition to usual aftercare for patients during the transition from hospital to home would increase hope, reduce loneliness, improve quality of life and show cost effectiveness compared with patients receiving usual aftercare only, with follow-up at one and three-months post-discharge. Results A total of 46 service users were recruited to the study; 23 receiving peer support and 23 in the care-as-usual arm. While this pilot trial found no statistically significant benefits for peer support on the primary or secondary outcome measures, there is an indication that hope may be further increased in those in receipt of peer support. The total cost per case for the peer support arm of the study was £2154 compared to £1922 for the control arm. The mean difference between costs was minimal and not statistically significant. However, further analyses demonstrated that peer support has a reasonably high probability of being more cost effective for a modest positive change in the measure of hopelessness. Challenges faced in recruitment and follow-up are explored alongside limitations in the delivery of peer support. Conclusions The findings suggest there is merit in conducting further research on peer support in the transition from hospital to home consideration should be applied to the nature of the patient population to whom support is offered; the length and frequency of support provided; and the contact between peer supporters and mental health staff. There is no conclusive evidence to support the cost effectiveness of providing peer support, but neither was it proven a costly intervention to deliver. The findings support an argument for a larger scale trial of peer support as an adjunct to existing services. Trial registration Current Controlled Trials ISRCTN74852771 PMID:24495599
Simpson, Alan; Flood, Chris; Rowe, Julie; Quigley, Jody; Henry, Susan; Hall, Cerdic; Evans, Richard; Sherman, Paul; Bowers, Len
2014-02-05
Mental health patients can feel anxious about losing the support of staff and patients when discharged from hospital and often discontinue treatment, experience relapse and readmission to hospital, and sometimes attempt suicide. The benefits of peer support in mental health services have been identified in a number of studies with some suggesting clinical and economic gains in patients being discharged. This pilot randomised controlled trial with economic evaluation aimed to explore whether peer support in addition to usual aftercare for patients during the transition from hospital to home would increase hope, reduce loneliness, improve quality of life and show cost effectiveness compared with patients receiving usual aftercare only, with follow-up at one and three-months post-discharge. A total of 46 service users were recruited to the study; 23 receiving peer support and 23 in the care-as-usual arm. While this pilot trial found no statistically significant benefits for peer support on the primary or secondary outcome measures, there is an indication that hope may be further increased in those in receipt of peer support. The total cost per case for the peer support arm of the study was £2154 compared to £1922 for the control arm. The mean difference between costs was minimal and not statistically significant. However, further analyses demonstrated that peer support has a reasonably high probability of being more cost effective for a modest positive change in the measure of hopelessness. Challenges faced in recruitment and follow-up are explored alongside limitations in the delivery of peer support. The findings suggest there is merit in conducting further research on peer support in the transition from hospital to home consideration should be applied to the nature of the patient population to whom support is offered; the length and frequency of support provided; and the contact between peer supporters and mental health staff. There is no conclusive evidence to support the cost effectiveness of providing peer support, but neither was it proven a costly intervention to deliver. The findings support an argument for a larger scale trial of peer support as an adjunct to existing services. Current Controlled Trials ISRCTN74852771.
Dória, Maria Luisa; McKenzie, James S.; Mroz, Anna; Phelps, David L.; Speller, Abigail; Rosini, Francesca; Strittmatter, Nicole; Golf, Ottmar; Veselkov, Kirill; Brown, Robert; Ghaem-Maghami, Sadaf; Takats, Zoltan
2016-01-01
Ovarian cancer is highly prevalent among European women, and is the leading cause of gynaecological cancer death. Current histopathological diagnoses of tumour severity are based on interpretation of, for example, immunohistochemical staining. Desorption electrospray mass spectrometry imaging (DESI-MSI) generates spatially resolved metabolic profiles of tissues and supports an objective investigation of tumour biology. In this study, various ovarian tissue types were analysed by DESI-MSI and co-registered with their corresponding haematoxylin and eosin (H&E) stained images. The mass spectral data reveal tissue type-dependent lipid profiles which are consistent across the n = 110 samples (n = 107 patients) used in this study. Multivariate statistical methods were used to classify samples and identify molecular features discriminating between tissue types. Three main groups of samples (epithelial ovarian carcinoma, borderline ovarian tumours, normal ovarian stroma) were compared as were the carcinoma histotypes (serous, endometrioid, clear cell). Classification rates >84% were achieved for all analyses, and variables differing statistically between groups were determined and putatively identified. The changes noted in various lipid types help to provide a context in terms of tumour biochemistry. The classification of unseen samples demonstrates the capability of DESI-MSI to characterise ovarian samples and to overcome existing limitations in classical histopathology. PMID:27976698
NASA Astrophysics Data System (ADS)
Mitchell, Bruce C.; Chakraborty, Jayajit
2015-11-01
Heat waves are the most significant cause of mortality in the US compared to other natural hazards. Prior studies have found increased heat exposure for individuals of lower socioeconomic status in several US cities, but few comparative analyses of the social distribution of urban heat have been conducted. To address this gap, our paper examines and compares the environmental justice consequences of urban heat risk in the three largest US cities: New York City, Los Angeles, and Chicago. Risk to urban heat is estimated on the basis of three characteristics of the urban thermal landscape: land surface temperature, vegetation abundance, and structural density of the built urban environment. These variables are combined to develop an urban heat risk index, which is then statistically compared with social vulnerability indicators representing socioeconomic status, age, disability, race/ethnicity, and linguistic isolation. The results indicate a consistent and significant statistical association between lower socioeconomic and minority status and greater urban heat risk, in all three cities. Our findings support a growing body of environmental justice literature that indicates the presence of a landscape of thermal inequity in US cities and underscores the need to conduct comparative analyses of social inequities in exposure to urban heat.
MOLSIM: A modular molecular simulation software
Jurij, Reščič
2015-01-01
The modular software MOLSIM for all‐atom molecular and coarse‐grained simulations is presented with focus on the underlying concepts used. The software possesses four unique features: (1) it is an integrated software for molecular dynamic, Monte Carlo, and Brownian dynamics simulations; (2) simulated objects are constructed in a hierarchical fashion representing atoms, rigid molecules and colloids, flexible chains, hierarchical polymers, and cross‐linked networks; (3) long‐range interactions involving charges, dipoles and/or anisotropic dipole polarizabilities are handled either with the standard Ewald sum, the smooth particle mesh Ewald sum, or the reaction‐field technique; (4) statistical uncertainties are provided for all calculated observables. In addition, MOLSIM supports various statistical ensembles, and several types of simulation cells and boundary conditions are available. Intermolecular interactions comprise tabulated pairwise potentials for speed and uniformity and many‐body interactions involve anisotropic polarizabilities. Intramolecular interactions include bond, angle, and crosslink potentials. A very large set of analyses of static and dynamic properties is provided. The capability of MOLSIM can be extended by user‐providing routines controlling, for example, start conditions, intermolecular potentials, and analyses. An extensive set of case studies in the field of soft matter is presented covering colloids, polymers, and crosslinked networks. © 2015 The Authors. Journal of Computational Chemistry Published by Wiley Periodicals, Inc. PMID:25994597
Cyber Risk Management for Critical Infrastructure: A Risk Analysis Model and Three Case Studies.
Paté-Cornell, M-Elisabeth; Kuypers, Marshall; Smith, Matthew; Keller, Philip
2018-02-01
Managing cyber security in an organization involves allocating the protection budget across a spectrum of possible options. This requires assessing the benefits and the costs of these options. The risk analyses presented here are statistical when relevant data are available, and system-based for high-consequence events that have not happened yet. This article presents, first, a general probabilistic risk analysis framework for cyber security in an organization to be specified. It then describes three examples of forward-looking analyses motivated by recent cyber attacks. The first one is the statistical analysis of an actual database, extended at the upper end of the loss distribution by a Bayesian analysis of possible, high-consequence attack scenarios that may happen in the future. The second is a systems analysis of cyber risks for a smart, connected electric grid, showing that there is an optimal level of connectivity. The third is an analysis of sequential decisions to upgrade the software of an existing cyber security system or to adopt a new one to stay ahead of adversaries trying to find their way in. The results are distributions of losses to cyber attacks, with and without some considered countermeasures in support of risk management decisions based both on past data and anticipated incidents. © 2017 Society for Risk Analysis.
Secondary Analysis of National Longitudinal Transition Study 2 Data
ERIC Educational Resources Information Center
Hicks, Tyler A.; Knollman, Greg A.
2015-01-01
This review examines published secondary analyses of National Longitudinal Transition Study 2 (NLTS2) data, with a primary focus upon statistical objectives, paradigms, inferences, and methods. Its primary purpose was to determine which statistical techniques have been common in secondary analyses of NLTS2 data. The review begins with an…
A Nonparametric Geostatistical Method For Estimating Species Importance
Andrew J. Lister; Rachel Riemann; Michael Hoppus
2001-01-01
Parametric statistical methods are not always appropriate for conducting spatial analyses of forest inventory data. Parametric geostatistical methods such as variography and kriging are essentially averaging procedures, and thus can be affected by extreme values. Furthermore, non normal distributions violate the assumptions of analyses in which test statistics are...
ERIC Educational Resources Information Center
Ellis, Barbara G.; Dick, Steven J.
1996-01-01
Employs the statistics-documentation portion of a word-processing program's grammar-check feature together with qualitative analyses to determine that Henry Watterson, long-time editor of the "Louisville Courier-Journal," was probably the South's famed Civil War correspondent "Shadow." (TB)
Hendricks, Deborah J; Sampson, Elaine; Rumrill, Phillip; Leopold, Anne; Elias, Eileen; Jacobs, Karen; Nardone, Amanda; Scherer, Marcia; Stauffer, Callista
2015-01-01
This article describes the activities and interim outcomes of a multi-site development project called Project Career, designed to promote cognitive support technology (CST) use and employment success for college and university students with traumatic brain injuries (TBIs). To obtain early intervention results from participants in Project Career's first 18 months of operation. Fifty-six students with TBI have participated to date across three implementation sites in Massachusetts, Ohio, and West Virginia, with 25 of these participants being military veterans. Descriptive analyses provide information regarding the participants, the barriers they face due to their TBI in obtaining a post-secondary education, and the impact services provided by Project Career have had to date in ameliorating those difficulties. Inferential statistical analyses provide preliminary results regarding program effectiveness. Preliminary results indicate the program is encouraging students to use CST strategies in the form of iPads and cognitive enhancement applications (also known as 'apps'). Significant results indicate participants are more positive, independent, and social; participants have a more positive attitude toward technology after six months in the program; and participants reported significantly improved experiences with technology during their first six months in the program. Participating students are actively preparing for their careers after graduation through a wide range of intensive vocational supports provided by project staff members.
Alignment of practice guidelines with targeted-therapy drug funding policies in Ontario.
Ramjeesingh, R; Meyer, R M; Brouwers, M; Chen, B E; Booth, C M
2013-02-01
We evaluated clinical practice guideline (cpg) recommendations from Cancer Care Ontario's Program in Evidence-Based Care (pebc) for molecularly targeted systemic treatments (tts) and subsequent funding decisions from the Ontario Ministry of Health and Long-Term Care. We identified pebc cpgs on tt published before June 1, 2010, and extracted information regarding the key evidence cited in support of cpg recommendations and the effect size associated with each tt. Those variables were compared with mohltc funding decisions as of June 2011. From 23 guidelines related to 17 tts, we identified 43 recommendations, among which 38 (88%) endorsed tt use. Among all the recommendations, 38 (88%) were based on published key evidence, with 82% (31 of 38) being supported by meta-analyses or phase iii trials. For the 38 recommendations endorsing tts, funding was approved in 28 (74%; odds ratio related to cpg recommendation: 29.9; p = 0.003). We were unable to demonstrate that recommendations associated with statistically significant improvements in overall survival [os: 14 of 16 (88%) vs. 8 of 14 (57%); p = 0.10] or disease- (dfs) or progression-free survival [pfs: 16 of 21 (76%) vs. 3 of 5 (60%); p = 0.59] were more likely to be funded than those with no significant difference. Moreover, we did not observe significant associations between funding approvals and absolute improvements of 3 months or more in os [6 of 6 (100%) vs. 3 of 6 (50%), p = 0.18] or pfs [6 of 8 (75%) vs. 10 of 12 (83%), p = 1.00]. For use of tts, most recommendations in pebc cpgs are based on meta-analyses or phase iii data, and funding decisions were strongly associated with those recommendations. Our data suggest a trend toward increased rates of funding for therapies with statistically significant improvements in os.
NASA Astrophysics Data System (ADS)
Khalid, A.; Haddad, J.; Lawler, S.; Ferreira, C.
2014-12-01
Areas along the Chesapeake Bay and its tributaries are extremely vulnerable to hurricane flooding, as evidenced by the costly effects and severe impacts of recent storms along the Virginia coast, such as Hurricane Isabel in 2003 and Hurricane Sandy in 2012. Coastal wetlands, in addition to their ecological importance, are expected to mitigate the impact of storm surge by acting as a natural protection against hurricane flooding. Quantifying such interactions helps to provide a sound scientific basis to support planning and decision making. Using storm surge flooding from various historical hurricanes, simulated using a coupled hydrodynamic wave model (ADCIRC-SWAN), we propose an integrated framework yielding a geospatial identification of the capacity of Chesapeake Bay wetlands to protect critical infrastructure. Spatial identification of Chesapeake Bay wetlands is derived from the National Wetlands Inventory (NWI), National Land Cover Database (NLCD), and the Coastal Change Analysis Program (C-CAP). Inventories of population and critical infrastructure are extracted from US Census block data and FEMA's HAZUS-Multi Hazard geodatabase. Geospatial and statistical analyses are carried out to develop a relationship between wetland land cover, hurricane flooding, population and infrastructure vulnerability. These analyses result in the identification and quantification of populations and infrastructure in flooded areas that lie within a reasonable buffer surrounding the identified wetlands. Our analysis thus produces a spatial perspective on the potential for wetlands to attenuate hurricane flood impacts in critical areas. Statistical analysis will support hypothesis testing to evaluate the benefits of wetlands from a flooding and storm-surge attenuation perspective. Results from geospatial analysis are used to identify where interactions with critical infrastructure are relevant in the Chesapeake Bay.
Development and psychometric testing of a new geriatric spiritual well-being scale.
Dunn, Karen S
2008-09-01
Aims and objectives. Assess the psychometric properties of a new geriatric spiritual well-being scale (GSWS), specifically designed for older adults. Background. Religiosity and spiritual wellness must be measured as two distinct concepts to prevent confounding them as synonymous among atheist and agnostic population. Design. A test-retest survey design was used to estimate the psychometric properties. Methods. A convenience sample of 138 community-dwelling older adults was drawn from the inner city of Detroit. Data were collected using telephone survey interviews. Data analyses included descriptive statistics, structural equation modelling, reliability analyses, and point-biserial correlations. Results. The factorial validity of the proposed model was not supported by the data. Fit indices were χ(2) = 185.98, d.f. = 98, P < 0.00, goodness-of-fit index of 0.85, comparative fit index of 0.87 and root mean error of approximation of 0.08, indicating a mediocre fit. Reliability statistics for the subscales ranged from being poor (0.36) to good (0.84) with an acceptable overall scale alpha of 0.76. Participants' performance stability and criterion-related validity were also supported. Conclusions. The GSWS is an age-specific assessment tool that was developed specifically to address a population's cultural diversity. Future research endeavors will be to test the psychometric properties of this scale in culturally diverse older adult populations for further instrument development. Relevance to clinical practice. Nurses need to recognize that agnostics/atheists have spiritual needs that do not include religious beliefs or practices. Thus, assessing patients' religious beliefs and practices prior to assessing spiritual well-being is essential to prevent bias. © 2008 The Author. Journal compilation © 2008 Blackwell Publishing Ltd.
Bunta, Ferenc; Douglas, Michael; Dickson, Hanna; Cantu, Amy; Wickesberg, Jennifer; Gifford, René H.
2015-01-01
Background There is a critical need to better understand speech and language development in bilingual children learning two spoken languages who use cochlear implants (CIs) and hearing aids (HAs). The paucity of knowledge in this area poses a significant barrier to providing maximal communicative outcomes to a growing number of children who have a hearing loss and are learning multiple spoken languages. In fact, the number of bilingual individuals receiving CIs and HAs is rapidly increasing, and Hispanic children display a higher prevalence of hearing loss than the general population of the United States (e.g., Mehra, Eavey, & Keamy, 2009). In order to better serve bilingual children with CIs and HAs, appropriate and effective therapy approaches need to be designed and tested, based on research findings. Aims This study investigated the effects of supporting both the home language (Spanish) and the language of the majority culture (English) on language outcomes in bilingual children with hearing loss (HL) who use CIs and HAs as compared to their bilingual peers who receive English only support. Methods and Procedures Retrospective analyses of language measures were completed for two groups of Spanish-and English-speaking bilingual children with HL who use CIs and HAs matched on a range of demographic and socio-economic variables: those with dual language support versus their peers with English only support. Dependent variables included scores from the English version of the Preschool Language Scales, 4th edition. Results Bilingual children who received dual language support outperformed their peers who received English only support at statistically significant levels as measured by Total Language and Expressive Communication as raw and language age scores. No statistically significant group differences were found on Auditory Comprehension scores. Conclusions In addition to providing support in English, encouraging home language use and providing treatment support in the first language may help rather than hinder development of both English and the home language in bilingual children with hearing loss who use CIs and HAs. In fact, dual language support may yield better overall and expressive English language outcomes than English only support for this population. PMID:27017913
Bunta, Ferenc; Douglas, Michael; Dickson, Hanna; Cantu, Amy; Wickesberg, Jennifer; Gifford, René H
2016-07-01
There is a critical need to understand better speech and language development in bilingual children learning two spoken languages who use cochlear implants (CIs) and hearing aids (HAs). The paucity of knowledge in this area poses a significant barrier to providing maximal communicative outcomes to a growing number of children who have a hearing loss (HL) and are learning multiple spoken languages. In fact, the number of bilingual individuals receiving CIs and HAs is rapidly increasing, and Hispanic children display a higher prevalence of HL than the general population of the United States. In order to serve better bilingual children with CIs and HAs, appropriate and effective therapy approaches need to be designed and tested, based on research findings. This study investigated the effects of supporting both the home language (Spanish) and the language of the majority culture (English) on language outcomes in bilingual children with HL who use CIs and HAs as compared to their bilingual peers who receive English-only support. Retrospective analyses of language measures were completed for two groups of Spanish- and English-speaking bilingual children with HL who use CIs and HAs matched on a range of demographic and socio-economic variables: those with dual-language support versus their peers with English-only support. Dependent variables included scores from the English version of the Preschool Language Scales, 4th Edition. Bilingual children who received dual-language support outperformed their peers who received English-only support at statistically significant levels as measured by Total Language and Expressive Communication as raw and language age scores. No statistically significant group differences were found on Auditory Comprehension scores. In addition to providing support in English, encouraging home language use and providing treatment support in the first language may help rather than hinder development of both English and the home language in bilingual children with HL who use CIs and HAs. In fact, dual-language support may yield better overall and expressive English language outcomes than English-only support for this population. © 2016 Royal College of Speech and Language Therapists.
Real-time quality assurance testing using photonic techniques: Application to iodine water system
NASA Technical Reports Server (NTRS)
Arendale, W. F.; Hatcher, Richard; Garlington, Yadilett; Harwell, Jack; Everett, Tracey
1990-01-01
A feasibility study of the use of inspection systems incorporating photonic sensors and multivariate analyses to provide an instrumentation system that in real-time assures quality and that the system in control has been conducted. A system is in control when the near future of the product quality is predictable. Off-line chemical analyses can be used for a chemical process when slow kinetics allows time to take a sample to the laboratory and the system provides a recovery mechanism that returns the system to statistical control without intervention of the operator. The objective for this study has been the implementation of do-it-right-the-first-time and just-in-time philosophies. The Environment Control and Life Support Systems (ECLSS) water reclamation system that adds iodine for biocidal control is an ideal candidate for the study and implementation of do-it-right-the-first-time technologies.
imDEV: a graphical user interface to R multivariate analysis tools in Microsoft Excel.
Grapov, Dmitry; Newman, John W
2012-09-01
Interactive modules for Data Exploration and Visualization (imDEV) is a Microsoft Excel spreadsheet embedded application providing an integrated environment for the analysis of omics data through a user-friendly interface. Individual modules enables interactive and dynamic analyses of large data by interfacing R's multivariate statistics and highly customizable visualizations with the spreadsheet environment, aiding robust inferences and generating information-rich data visualizations. This tool provides access to multiple comparisons with false discovery correction, hierarchical clustering, principal and independent component analyses, partial least squares regression and discriminant analysis, through an intuitive interface for creating high-quality two- and a three-dimensional visualizations including scatter plot matrices, distribution plots, dendrograms, heat maps, biplots, trellis biplots and correlation networks. Freely available for download at http://sourceforge.net/projects/imdev/. Implemented in R and VBA and supported by Microsoft Excel (2003, 2007 and 2010).
Psychological distress in Canada: the role of employment and reasons of non-employment.
Marchand, Alain; Drapeau, Aline; Beaulieu-Prévost, Dominic
2012-11-01
This study investigated variations in psychological distress in a large sample of the Canadian population according to employment status, occupation, work organization conditions, reasons for non-employment, stress and support outside the work environment, family situation and individual characteristics. Data came from cycle 4 (2000-1) of the Canadian National Population Health Survey conducted by Statistics Canada. Multiple regression analyses, adjusted for the family situation, the level of support from the social network and the individual characteristics, were carried out on a sample of 7258 individuals aged from 18 to 65 years. Occupation, social support at work, age, self-esteem, presence of children aged five and under and social support outside of the workplace were associated with lower levels of psychological distress, while permanent and temporary disability, psychological demands in the workplace, job insecurity, female gender, and stressful financial, marital and parental situations were related to higher levels of psychological distress. Findings from this study suggest that, in terms of psychological distress, having a job is not always better than non-employment, and that specific non-employment situations associate differently with psychological distress.
[Factors Influencing Burnout among Mothers of Children with Cerebral Palsy].
Seo, Ji Young; Lee, Hae Jin; You, Mi Ae
2017-04-01
The purpose of this study was to examine the effects of parental stress, social support, and coping behavior on burnout among mothers caring for children with cerebral palsy. Participants in this cross-sectional, descriptive study were 185 mothers who completed a self-report structured questionnaire. The data were analyzed using descriptive statistics, t-test, one-way ANOVA, correlation and multiple linear regression analyses with IBM SPSS Win 22 program. Parental stress and coping behavior were strong predictors of burnout among mothers of children with cerebral palsy. These variables explained 50.0% of the variance in burnout. Social support was not a predictor of burnout. A higher level of burnout was associated with higher levels of parental stress and lower levels of social support and coping behavior. Mothers of children with cerebral palsy are vulnerable to burnout. These results show that effective strategies for reducing parental stress and improving positive coping behavior are needed to reduce burnout in these mothers. © 2017 Korean Society of Nursing Science
Strnadová, Iva; Bernoldová, Jana; Adamčíková, Zdeňka; Klusáček, Jan
2017-05-01
This study examined the attitudes, knowledge and experiences of practitioners in social services and child welfare working with mothers with intellectual disability. The authors used a national survey, which was completed by 329 participants. Descriptive statistics and frequency tables were generated, and the associations between variables and differences between various subgroups of the sample were made. The open questions were analysed using the processes involved in content analysis. The findings indicated that the participants had limited knowledge of available supports and services for mothers with intellectual disability. Furthermore, many participants believed that mothers with intellectual disability should have an abortion should they become pregnant. The findings show practitioners' stereotyped attitudes towards mothers with intellectual disability. Workers in the area of social services and child welfare need access to training and professional development in the area of supporting mothers with intellectual disability. © 2016 John Wiley & Sons Ltd.
1993-08-01
subtitled "Simulation Data," consists of detailed infonrnation on the design parmneter variations tested, subsequent statistical analyses conducted...used with confidence during the design process. The data quality can be examined in various forms such as statistical analyses of measure of merit data...merit, such as time to capture or nmaximurn pitch rate, can be calculated from the simulation time history data. Statistical techniques are then used
Chang, Lin-Chau; Mahmood, Riaz; Qureshi, Samina; Breder, Christopher D
2017-01-01
Standardised MedDRA Queries (SMQs) have been developed since the early 2000's and used by academia, industry, public health, and government sectors for detecting safety signals in adverse event safety databases. The purpose of the present study is to characterize how SMQs are used and the impact in safety analyses for New Drug Application (NDA) and Biologics License Application (BLA) submissions to the United States Food and Drug Administration (USFDA). We used the PharmaPendium database to capture SMQ use in Summary Basis of Approvals (SBoAs) of drugs and biologics approved by the USFDA. Characteristics of the drugs and the SMQ use were employed to evaluate the role of SMQ safety analyses in regulatory decisions and the veracity of signals they revealed. A comprehensive search of the SBoAs yielded 184 regulatory submissions approved from 2006 to 2015. Search strategies more frequently utilized restrictive searches with "narrow terms" to enhance specificity over strategies using "broad terms" to increase sensitivity, while some involved modification of search terms. A majority (59%) of 1290 searches used descriptive statistics, however inferential statistics were utilized in 35% of them. Commentary from reviewers and supervisory staff suggested that a small, yet notable percentage (18%) of 1290 searches supported regulatory decisions. The searches with regulatory impact were found in 73 submissions (40% of the submissions investigated). Most searches (75% of 227 searches) with regulatory implications described how the searches were confirmed, indicating prudence in the decision-making process. SMQs have an increasing role in the presentation and review of safety analysis for NDAs/BLAs and their regulatory reviews. This study suggests that SMQs are best used for screening process, with descriptive statistics, description of SMQ modifications, and systematic verification of cases which is crucial for drawing regulatory conclusions.
Systematic meta-analyses and field synopsis of genetic association studies in colorectal adenomas
Montazeri, Zahra; Theodoratou, Evropi; Nyiraneza, Christine; Timofeeva, Maria; Chen, Wanjing; Svinti, Victoria; Sivakumaran, Shanya; Gresham, Gillian; Cubitt, Laura; Carvajal-Carmona, Luis; Bertagnolli, Monica M; Zauber, Ann G; Tomlinson, Ian; Farrington, Susan M; Dunlop, Malcolm G; Campbell, Harry; Little, Julian
2018-01-01
Background Low penetrance genetic variants, primarily single nucleotide polymorphisms, have substantial influence on colorectal cancer (CRC) susceptibility. Most CRCs develop from colorectal adenomas (CRA). Here, we report the first comprehensive field synopsis that catalogues all genetic association studies on CRA, with a parallel online database (http://www.chs.med.ed.ac.uk/CRAgene/). Methods We performed a systematic review, reviewing 9750 titles and then extracted data from 130 publications reporting on 181 polymorphisms in 74 genes. We conducted meta-analyses to derive summary effect estimates for 37 polymorphisms in 26 genes. We applied the Venice criteria and Bayesian False Discovery Probability (BFDP) to assess the levels of the credibility of associations. Results We considered the association with the rs6983267 variant at 8q24 as “highly credible”, reaching genome wide statistical significance in at least one meta-analysis model. We identified “less credible” associations (higher heterogeneity, lower statistical power, BFDP>0.02) with a further four variants of four independent genes: MTHFR c.677C>T p.A222V (rs1801133), TP53 c.215C>G p.R72P (rs1042522), NQO1 c.559C>T p.P187S (rs1800566), and NAT1 alleles imputed as fast acetylator genotypes. For the remaining 32 variants of 22 genes for which positive associations with CRA risk have been previously reported, the meta-analyses revealed no credible evidence to support these as true associations. Conclusions The limited number of credible associations between low penetrance genetic variants and CRA reflects the lower volume of evidence and associated lack of statistical power to detect associations of the magnitude typically observed for genetic variants and chronic diseases. The CRAgene database provides context for CRA genetic association data and will help inform future research directions. PMID:26451011
Chang, Lin-Chau; Mahmood, Riaz; Qureshi, Samina
2017-01-01
Purpose Standardised MedDRA Queries (SMQs) have been developed since the early 2000’s and used by academia, industry, public health, and government sectors for detecting safety signals in adverse event safety databases. The purpose of the present study is to characterize how SMQs are used and the impact in safety analyses for New Drug Application (NDA) and Biologics License Application (BLA) submissions to the United States Food and Drug Administration (USFDA). Methods We used the PharmaPendium database to capture SMQ use in Summary Basis of Approvals (SBoAs) of drugs and biologics approved by the USFDA. Characteristics of the drugs and the SMQ use were employed to evaluate the role of SMQ safety analyses in regulatory decisions and the veracity of signals they revealed. Results A comprehensive search of the SBoAs yielded 184 regulatory submissions approved from 2006 to 2015. Search strategies more frequently utilized restrictive searches with “narrow terms” to enhance specificity over strategies using “broad terms” to increase sensitivity, while some involved modification of search terms. A majority (59%) of 1290 searches used descriptive statistics, however inferential statistics were utilized in 35% of them. Commentary from reviewers and supervisory staff suggested that a small, yet notable percentage (18%) of 1290 searches supported regulatory decisions. The searches with regulatory impact were found in 73 submissions (40% of the submissions investigated). Most searches (75% of 227 searches) with regulatory implications described how the searches were confirmed, indicating prudence in the decision-making process. Conclusions SMQs have an increasing role in the presentation and review of safety analysis for NDAs/BLAs and their regulatory reviews. This study suggests that SMQs are best used for screening process, with descriptive statistics, description of SMQ modifications, and systematic verification of cases which is crucial for drawing regulatory conclusions. PMID:28570569
Chung, Sang M; Lee, David J; Hand, Austin; Young, Philip; Vaidyanathan, Jayabharathi; Sahajwalla, Chandrahas
2015-12-01
The study evaluated whether the renal function decline rate per year with age in adults varies based on two primary statistical analyses: cross-section (CS), using one observation per subject, and longitudinal (LT), using multiple observations per subject over time. A total of 16628 records (3946 subjects; age range 30-92 years) of creatinine clearance and relevant demographic data were used. On average, four samples per subject were collected for up to 2364 days (mean: 793 days). A simple linear regression and random coefficient models were selected for CS and LT analyses, respectively. The renal function decline rates per year were 1.33 and 0.95 ml/min/year for CS and LT analyses, respectively, and were slower when the repeated individual measurements were considered. The study confirms that rates are different based on statistical analyses, and that a statistically robust longitudinal model with a proper sampling design provides reliable individual as well as population estimates of the renal function decline rates per year with age in adults. In conclusion, our findings indicated that one should be cautious in interpreting the renal function decline rate with aging information because its estimation was highly dependent on the statistical analyses. From our analyses, a population longitudinal analysis (e.g. random coefficient model) is recommended if individualization is critical, such as a dose adjustment based on renal function during a chronic therapy. Copyright © 2015 John Wiley & Sons, Ltd.
Smith, Gillian E; Elliot, Alex J; Ibbotson, Sue; Morbey, Roger; Edeghere, Obaghe; Hawker, Jeremy; Catchpole, Mike; Endericks, Tina; Fisher, Paul; McCloskey, Brian
2017-09-01
Syndromic surveillance aims to provide early warning and real time estimates of the extent of incidents; and reassurance about lack of impact of mass gatherings. We describe a novel public health risk assessment process to ensure those leading the response to the 2012 Olympic Games were alerted to unusual activity that was of potential public health importance, and not inundated with multiple statistical 'alarms'. Statistical alarms were assessed to identify those which needed to result in 'alerts' as reliably as possible. There was no previously developed method for this. We identified factors that increased our concern about an alarm suggesting that an 'alert' should be made. Between 2 July and 12 September 2012, 350 674 signals were analysed resulting in 4118 statistical alarms. Using the risk assessment process, 122 'alerts' were communicated to Olympic incident directors. Use of a novel risk assessment process enabled the interpretation of large number of statistical alarms in a manageable way for the period of a sustained mass gathering. This risk assessment process guided the prioritization and could be readily adapted to other surveillance systems. The process, which is novel to our knowledge, continues as a legacy of the Games. © Crown copyright 2016.
Content-Based VLE Designs Improve Learning Efficiency in Constructivist Statistics Education
Wessa, Patrick; De Rycker, Antoon; Holliday, Ian Edward
2011-01-01
Background We introduced a series of computer-supported workshops in our undergraduate statistics courses, in the hope that it would help students to gain a deeper understanding of statistical concepts. This raised questions about the appropriate design of the Virtual Learning Environment (VLE) in which such an approach had to be implemented. Therefore, we investigated two competing software design models for VLEs. In the first system, all learning features were a function of the classical VLE. The second system was designed from the perspective that learning features should be a function of the course's core content (statistical analyses), which required us to develop a specific–purpose Statistical Learning Environment (SLE) based on Reproducible Computing and newly developed Peer Review (PR) technology. Objectives The main research question is whether the second VLE design improved learning efficiency as compared to the standard type of VLE design that is commonly used in education. As a secondary objective we provide empirical evidence about the usefulness of PR as a constructivist learning activity which supports non-rote learning. Finally, this paper illustrates that it is possible to introduce a constructivist learning approach in large student populations, based on adequately designed educational technology, without subsuming educational content to technological convenience. Methods Both VLE systems were tested within a two-year quasi-experiment based on a Reliable Nonequivalent Group Design. This approach allowed us to draw valid conclusions about the treatment effect of the changed VLE design, even though the systems were implemented in successive years. The methodological aspects about the experiment's internal validity are explained extensively. Results The effect of the design change is shown to have substantially increased the efficiency of constructivist, computer-assisted learning activities for all cohorts of the student population under investigation. The findings demonstrate that a content–based design outperforms the traditional VLE–based design. PMID:21998652
Schunn, Anne-Marie; Conraths, Franz J.; Staubach, Christoph; Fröhlich, Andreas; Forbes, Andrew; Strube, Christina
2013-01-01
In November 2008, a total of 19,910 bulk tank milk (BTM) samples were obtained from dairy farms from all over Germany, corresponding to about 20% of all German dairy herds, and analysed for antibodies against the bovine lungworm Dictyocaulus viviparus by use of the recombinant MSP-ELISA. A total number of 3,397 (17.1%; n = 19,910) BTM samples tested seropositive. The prevalences in individual German federal states varied between 0.0% and 31.2% positive herds. A geospatial map was drawn to show the distribution of seropositive and seronegative herds per postal code area. ELISA results were further analysed for associations with land-use and climate data. Bivariate statistical analysis was used to identify potential spatial risk factors for dictyocaulosis. Statistically significant positive associations were found between lungworm seropositive herds and the proportion of water bodies and grassed area per postal code area. Variables that showed a statistically significant association with a positive BTM test were included in a logistic regression model, which was further refined by controlled stepwise selection of variables. The low Pseudo R2 values (0.08 for the full model and 0.06 for the final model) and further evaluation of the model by ROC analysis indicate that additional, unrecorded factors (e.g. management factors) or random effects may substantially contribute to lungworm infections in dairy cows. Veterinarians should include lungworms in the differential diagnosis of respiratory disease in dairy cattle, particularly those at pasture. Monitoring of herds through BTM screening for antibodies can help farmers and veterinarians plan and implement appropriate control measures. PMID:24040243
Perspective of pharmacists in Qatar regarding doping and anti-doping in sports.
Mottram, David; Khalifa, Sherief; Alemrayat, Bayan; Rahhal, Alaa; Ahmed, Afif; Stuart, Mark; Awaisu, Ahmed
2016-06-01
The aim of this study was to evaluate the current knowledge and perceptions of pharmacists in Qatar with regard to the use of drugs in sport and to explore their views on the introduction of education and training in the area of sports pharmacy. A cross-sectional survey was conducted targeting both hospital and community pharmacists in Qatar. A questionnaire consisting of three domains pertaining to participants' knowledge, perceived role of healthcare professionals, and attitudes towards educational needs on the use of drugs in sports was developed and validated. The online survey link and paper-based questionnaires were distributed to the target population. Data analyses were performed using IBM SPSS Statistics. Descriptive and inferential statistics were utilized for the analyses, where P<0.05 indicates statistical significance. A total of 300 pharmacists responded to the survey. Respondents had a limited awareness of doping and anti-doping and achieved an average knowledge score of 53.2% regarding the prohibited status of drugs that may be used by athletes, particularly with respect to over-the-counter medicines and supplements. The majority (81.7%) of the pharmacists expressed an interest in receiving education and training on sports pharmacy. Specialized training programs are warranted to ensure that pharmacists have the knowledge and skills required to provide athletes with accurate information about anti-doping issues and the safe and effective use of medicines in sport. The development of these programs should be supported by national pharmacy policy makers and designed in collaboration with anti-doping agencies and sports pharmacy experts and educators.
Perlman, Michal; Falenchuk, Olesya; Fletcher, Brooke; McMullen, Evelyn; Beyene, Joseph; Shah, Prakesh S
2016-01-01
The quality of staff/child interactions as measured by the Classroom Assessment Scoring System (CLASS) in Early Childhood Education and Care (ECEC) programs is thought to be important for children's outcomes. The CLASS is made of three domains that assess Emotional Support, Classroom Organization and Instructional Support. It is a relatively new measure that is being used increasingly for research, quality monitoring/accountability and other applied purposes. Our objective was to evaluate the association between the CLASS and child outcomes. Searches of Medline, PsycINFO, ERIC, websites of large datasets and reference sections of all retrieved articles were conducted up to July 3, 2015. Studies that measured association between the CLASS and child outcomes for preschool-aged children who attended ECEC programs were included after screening by two independent reviewers. Searches and data extraction were conducted by two independent reviewers. Thirty-five studies were systematically reviewed of which 19 provided data for meta-analyses. Most studies had moderate to high risk of bias. Of the 14 meta-analyses we conducted, associations between Classroom Organization and Pencil Tapping and between Instructional Support and SSRS Social Skills were significant with pooled correlations of .06 and .09 respectively. All associations were in the expected direction. In the systematic review, significant correlations were reported mainly from one large dataset. Substantial heterogeneity in use of the CLASS, its dimensions, child outcomes and statistical measures was identified. Greater consistency in study methodology is urgently needed. Given the multitude of factors that impact child development it is encouraging that our analyses revealed some, although small, associations between the CLASS and children's outcomes.
Perlman, Michal; Falenchuk, Olesya; Fletcher, Brooke; McMullen, Evelyn; Beyene, Joseph; Shah, Prakesh S.
2016-01-01
The quality of staff/child interactions as measured by the Classroom Assessment Scoring System (CLASS) in Early Childhood Education and Care (ECEC) programs is thought to be important for children’s outcomes. The CLASS is made of three domains that assess Emotional Support, Classroom Organization and Instructional Support. It is a relatively new measure that is being used increasingly for research, quality monitoring/accountability and other applied purposes. Our objective was to evaluate the association between the CLASS and child outcomes. Searches of Medline, PsycINFO, ERIC, websites of large datasets and reference sections of all retrieved articles were conducted up to July 3, 2015. Studies that measured association between the CLASS and child outcomes for preschool-aged children who attended ECEC programs were included after screening by two independent reviewers. Searches and data extraction were conducted by two independent reviewers. Thirty-five studies were systematically reviewed of which 19 provided data for meta-analyses. Most studies had moderate to high risk of bias. Of the 14 meta-analyses we conducted, associations between Classroom Organization and Pencil Tapping and between Instructional Support and SSRS Social Skills were significant with pooled correlations of .06 and .09 respectively. All associations were in the expected direction. In the systematic review, significant correlations were reported mainly from one large dataset. Substantial heterogeneity in use of the CLASS, its dimensions, child outcomes and statistical measures was identified. Greater consistency in study methodology is urgently needed. Given the multitude of factors that impact child development it is encouraging that our analyses revealed some, although small, associations between the CLASS and children’s outcomes. PMID:28036333
Inferential Statistics in "Language Teaching Research": A Review and Ways Forward
ERIC Educational Resources Information Center
Lindstromberg, Seth
2016-01-01
This article reviews all (quasi)experimental studies appearing in the first 19 volumes (1997-2015) of "Language Teaching Research" (LTR). Specifically, it provides an overview of how statistical analyses were conducted in these studies and of how the analyses were reported. The overall conclusion is that there has been a tight adherence…
Heckman, Timothy G; Heckman, Bernadette D; Anderson, Timothy; Lovejoy, Travis I; Markowitz, John C; Shen, Ye; Sutton, Mark
2017-01-01
Human immunodeficiency virus (HIV)-positive rural individuals carry a 1.3-times greater risk of a depressive diagnosis than their urban counterparts. This randomized clinical trial tested whether telephone-administered interpersonal psychotherapy (tele-IPT) acutely relieved depressive symptoms in 132 HIV-infected rural persons from 28 states diagnosed with Diagnostic and Statistical Manual of Mental Disorders-IV major depressive disorder (MDD), partially remitted MDD, or dysthymic disorder. Patients were randomized to either 9 sessions of one-on-one tele-IPT (n = 70) or standard care (SC; n = 62). A series of intent-to-treat (ITT), therapy completer, and sensitivity analyses assessed changes in depressive symptoms, interpersonal problems, and social support from pre- to postintervention. Across all analyses, tele-IPT patients reported significantly lower depressive symptoms and interpersonal problems than SC controls; 22% of tele-IPT patients were categorized as a priori "responders" who reported 50% or higher reductions in depressive symptoms compared to only 4% of SC controls in ITT analyses. Brief tele-IPT acutely decreased depressive symptoms and interpersonal problems in depressed rural people living with HIV.
Roets-Merken, Lieve M; Zuidema, Sytse U; Vernooij-Dassen, Myrra J F J; Teerenstra, Steven; Hermsen, Pieter G J M; Kempen, Gertrudis I J M; Graff, Maud J L
2018-01-01
Objective To evaluate the effectiveness of a nurse-supported self-management programme to improve social participation of dual sensory impaired older adults in long-term care homes. Design Cluster randomised controlled trial. Setting Thirty long-term care homes across the Netherlands. Participants Long-term care homes were randomised into intervention clusters (n=17) and control clusters (n=13), involving 89 dual sensory impaired older adults and 56 licensed practical nurses. Intervention Nurse-supported self-management programme. Measurements Effectiveness was evaluated by the primary outcome social participation using a participation scale adapted for visually impaired older adults distinguishing four domains: instrumental activities of daily living, social-cultural activities, high-physical-demand and low-physical-demand leisure activities. A questionnaire assessing hearing-related participation problems was added as supportive outcome. Secondary outcomes were autonomy, control, mood and quality of life and nurses’ job satisfaction. For effectiveness analyses, linear mixed models were used. Sampling and intervention quality were analysed using descriptive statistics. Results Self-management did not affect all four domains of social participation; however. the domain ‘instrumental activities of daily living’ had a significant effect in favour of the intervention group (P=0.04; 95% CI 0.12 to 8.5). Sampling and intervention quality was adequate. Conclusions A nurse-supported self-management programme was effective in empowering the dual sensory impaired older adults to address the domain ‘instrumental activities of daily living’, but no differences were found in addressing the other three participation domains. Self-management showed to be beneficial for managing practical problems, but not for those problems requiring behavioural adaptations of other persons. Trial registration number NCT01217502; Results. PMID:29371264
Seven new dolphin mitochondrial genomes and a time-calibrated phylogeny of whales
Xiong, Ye; Brandley, Matthew C; Xu, Shixia; Zhou, Kaiya; Yang, Guang
2009-01-01
Background The phylogeny of Cetacea (whales) is not fully resolved with substantial support. The ambiguous and conflicting results of multiple phylogenetic studies may be the result of the use of too little data, phylogenetic methods that do not adequately capture the complex nature of DNA evolution, or both. In addition, there is also evidence that the generic taxonomy of Delphinidae (dolphins) underestimates its diversity. To remedy these problems, we sequenced the complete mitochondrial genomes of seven dolphins and analyzed these data with partitioned Bayesian analyses. Moreover, we incorporate a newly-developed "relaxed" molecular clock to model heterogenous rates of evolution among cetacean lineages. Results The "deep" phylogenetic relationships are well supported including the monophyly of Cetacea and Odontoceti. However, there is ambiguity in the phylogenetic affinities of two of the river dolphin clades Platanistidae (Indian River dolphins) and Lipotidae (Yangtze River dolphins). The phylogenetic analyses support a sister relationship between Delphinidae and Monodontidae + Phocoenidae. Additionally, there is statistically significant support for the paraphyly of Tursiops (bottlenose dolphins) and Stenella (spotted dolphins). Conclusion Our phylogenetic analysis of complete mitochondrial genomes using recently developed models of rate autocorrelation resolved the phylogenetic relationships of the major Cetacean lineages with a high degree of confidence. Our results indicate that a rapid radiation of lineages explains the lack of support the placement of Platanistidae and Lipotidae. Moreover, our estimation of molecular divergence dates indicates that these radiations occurred in the Middle to Late Oligocene and Middle Miocene, respectively. Furthermore, by collecting and analyzing seven new mitochondrial genomes, we provide strong evidence that the delphinid genera Tursiops and Stenella are not monophyletic, and the current taxonomy masks potentially interesting patterns of morphological, physiological, behavioral, and ecological evolution. PMID:19166626
Bohler, Anwesha; Eijssen, Lars M T; van Iersel, Martijn P; Leemans, Christ; Willighagen, Egon L; Kutmon, Martina; Jaillard, Magali; Evelo, Chris T
2015-08-23
Biological pathways are descriptive diagrams of biological processes widely used for functional analysis of differentially expressed genes or proteins. Primary data analysis, such as quality control, normalisation, and statistical analysis, is often performed in scripting languages like R, Perl, and Python. Subsequent pathway analysis is usually performed using dedicated external applications. Workflows involving manual use of multiple environments are time consuming and error prone. Therefore, tools are needed that enable pathway analysis directly within the same scripting languages used for primary data analyses. Existing tools have limited capability in terms of available pathway content, pathway editing and visualisation options, and export file formats. Consequently, making the full-fledged pathway analysis tool PathVisio available from various scripting languages will benefit researchers. We developed PathVisioRPC, an XMLRPC interface for the pathway analysis software PathVisio. PathVisioRPC enables creating and editing biological pathways, visualising data on pathways, performing pathway statistics, and exporting results in several image formats in multiple programming environments. We demonstrate PathVisioRPC functionalities using examples in Python. Subsequently, we analyse a publicly available NCBI GEO gene expression dataset studying tumour bearing mice treated with cyclophosphamide in R. The R scripts demonstrate how calls to existing R packages for data processing and calls to PathVisioRPC can directly work together. To further support R users, we have created RPathVisio simplifying the use of PathVisioRPC in this environment. We have also created a pathway module for the microarray data analysis portal ArrayAnalysis.org that calls the PathVisioRPC interface to perform pathway analysis. This module allows users to use PathVisio functionality online without having to download and install the software and exemplifies how the PathVisioRPC interface can be used by data analysis pipelines for functional analysis of processed genomics data. PathVisioRPC enables data visualisation and pathway analysis directly from within various analytical environments used for preliminary analyses. It supports the use of existing pathways from WikiPathways or pathways created using the RPC itself. It also enables automation of tasks performed using PathVisio, making it useful to PathVisio users performing repeated visualisation and analysis tasks. PathVisioRPC is freely available for academic and commercial use at http://projects.bigcat.unimaas.nl/pathvisiorpc.
Reporting and methodological quality of meta-analyses in urological literature.
Xia, Leilei; Xu, Jing; Guzzo, Thomas J
2017-01-01
To assess the overall quality of published urological meta-analyses and identify predictive factors for high quality. We systematically searched PubMed to identify meta-analyses published from January 1st, 2011 to December 31st, 2015 in 10 predetermined major paper-based urology journals. The characteristics of the included meta-analyses were collected, and their reporting and methodological qualities were assessed by the PRISMA checklist (27 items) and AMSTAR tool (11 items), respectively. Descriptive statistics were used for individual items as a measure of overall compliance, and PRISMA and AMSTAR scores were calculated as the sum of adequately reported domains. Logistic regression was used to identify predictive factors for high qualities. A total of 183 meta-analyses were included. The mean PRISMA and AMSTAR scores were 22.74 ± 2.04 and 7.57 ± 1.41, respectively. PRISMA item 5, protocol and registration, items 15 and 22, risk of bias across studies, items 16 and 23, additional analysis had less than 50% adherence. AMSTAR item 1, " a priori " design, item 5, list of studies and item 10, publication bias had less than 50% adherence. Logistic regression analyses showed that funding support and " a priori " design were associated with superior reporting quality, following PRISMA guideline and " a priori " design were associated with superior methodological quality. Reporting and methodological qualities of recently published meta-analyses in major paper-based urology journals are generally good. Further improvement could potentially be achieved by strictly adhering to PRISMA guideline and having " a priori " protocol.
Enarson, C; Cariaga-Lo, L
2001-11-01
The results of the United States Medical Licensing Examination Step 1 and 2 examinations are reported for students enrolled in a problem-based and traditional lecture-based curricula over a seven-year period at a single institution. There were no statistically significant differences in mean scores on either examination over the seven year period as a whole. There were statistically significant main effects noted by cohort year and curricular track for both the Step 1 and 2 examinations. These results support the general, long-term effectiveness of problem-based learning with respect to basic and clinical science knowledge acquisition. This paper reports the United States Medical Licensing Examination Step 1 and Step 2 results for students enrolled in a problem-based and traditional lecture-based learning curricula over the seven-year period (1992-98) in order to evaluate the adequacy of each curriculum in supporting students learning of the basic and clinical sciences. Six hundred and eighty-nine students who took the United States Medical Licensing Examination Step 1 and 540 students who took Step 2 for the first time over the seven-year period were included in the analyses. T-test analyses were utilized to compare students' Step 1 and Step 2 performance by curriculum groups. United States Medical Licensing Examination Step 1 scores over the seven-year period were 214 for Traditional Curriculum students and 208 for Parallel Curriculum students (t-value = 1.32, P=0.21). Mean Step 2 scores over the seven-year period were 208 for Traditional Curriculum students and 206 for Parallel Curriculum students (t-value=1.08, P=0.30). Statistically significant main effects were noted by cohort year and curricular track for both the Step 1 and Step 2 examinations. The totality of experience in both groups, although differing by curricular type, may be similar enough that the comparable scores are what should be expected. These results should be reassuring to curricular planners and faculty that problem-based learning can provide students with the knowledge needed for the subsequent phases of their medical education.
Trait humor and longevity: do comics have the last laugh?
Rotton, J
1992-01-01
Four sets of biographical data were analyzed in order to test the hypothesis that the ability to generate humor is associated with longevity. Although steps were taken to ensure that tests had high levels of statistical power, analyses provided very little support for the idea that individuals with a well-developed sense of humor live longer than serious writers and other entertainers. In addition, a subsidiary analysis revealed that those in the business of entertaining others died at an earlier age than those in other lines of endeavor. These findings suggest that researchers should turn their attention from trait humor to the effects of humorous material.
Oliveira, J T; Santos, T C; Martins, L; Silva, M A; Marques, A P; Castro, A G; Neves, N M; Reis, R L
2009-10-01
Gellan gum is a polysaccharide that has been recently proposed by our group for cartilage tissue-engineering applications. It is commonly used in the food and pharmaceutical industry and has the ability to form stable gels without the use of harsh reagents. Gellan gum can function as a minimally invasive injectable system, gelling inside the body in situ under physiological conditions and efficiently adapting to the defect site. In this work, gellan gum hydrogels were combined with human articular chondrocytes (hACs) and were subcutaneously implanted in nude mice for 4 weeks. The implants were collected for histological (haematoxylin and eosin and Alcian blue staining), biochemical [dimethylmethylene blue (GAG) assay], molecular (real-time PCR analyses for collagen types I, II and X, aggrecan) and immunological analyses (immunolocalization of collagen types I and II). The results showed a homogeneous cell distribution and the typical round-shaped morphology of the chondrocytes within the matrix upon implantation. Proteoglycans synthesis was detected by Alcian blue staining and a statistically significant increase of proteoglycans content was measured with the GAG assay quantified from 1 to 4 weeks of implantation. Real-time PCR analyses showed a statistically significant upregulation of collagen type II and aggrecan levels in the same periods. The immunological assays suggest deposition of collagen type II along with some collagen type I. The overall data shows that gellan gum hydrogels adequately support the growth and ECM deposition of human articular chondrocytes when implanted subcutaneously in nude mice. Copyright (c) 2009 John Wiley & Sons, Ltd.
Barber, Julie A; Thompson, Simon G
1998-01-01
Objective To review critically the statistical methods used for health economic evaluations in randomised controlled trials where an estimate of cost is available for each patient in the study. Design Survey of published randomised trials including an economic evaluation with cost values suitable for statistical analysis; 45 such trials published in 1995 were identified from Medline. Main outcome measures The use of statistical methods for cost data was assessed in terms of the descriptive statistics reported, use of statistical inference, and whether the reported conclusions were justified. Results Although all 45 trials reviewed apparently had cost data for each patient, only 9 (20%) reported adequate measures of variability for these data and only 25 (56%) gave results of statistical tests or a measure of precision for the comparison of costs between the randomised groups. Only 16 (36%) of the articles gave conclusions which were justified on the basis of results presented in the paper. No paper reported sample size calculations for costs. Conclusions The analysis and interpretation of cost data from published trials reveal a lack of statistical awareness. Strong and potentially misleading conclusions about the relative costs of alternative therapies have often been reported in the absence of supporting statistical evidence. Improvements in the analysis and reporting of health economic assessments are urgently required. Health economic guidelines need to be revised to incorporate more detailed statistical advice. Key messagesHealth economic evaluations required for important healthcare policy decisions are often carried out in randomised controlled trialsA review of such published economic evaluations assessed whether statistical methods for cost outcomes have been appropriately used and interpretedFew publications presented adequate descriptive information for costs or performed appropriate statistical analysesIn at least two thirds of the papers, the main conclusions regarding costs were not justifiedThe analysis and reporting of health economic assessments within randomised controlled trials urgently need improving PMID:9794854
Zhang, Xiao-Mei; Lv, Fang; Wang, Pin; Huang, Xia-Man; Liu, Kai-Feng; Pan, Yu; Dong, Nai-Jun; Ji, Yu-Rong; She, Hong; Hu, Rong
2015-02-01
Meta-analyses have found conflicting results with respect to the use of progesterone or progesterone plus estrogen as luteal phase support for in vitro fertilization (IVF) protocols involving gonadotropins and/or gonadotropin-releasing hormone analogs. The aim of the present study was to perform an updated meta-analysis on the efficacy of progesterone versus progesterone plus estrogen as luteal phase support. We searched the MEDLINE, Cochrane Library, and Google Scholar databases (up to March 18, 2014). The search terms were (estrogen OR estradiol OR oestradiol) AND (progesterone) AND (IVF OR in vitro fertilization) AND (randomized OR prospective). We did not limit the form of estrogen and included subjects who contributed more than 1 cycle to a study. The primary outcome was clinical pregnancy rate. Secondary outcomes were ongoing pregnancy rate, fertilization rate, implantation rate, and miscarriage rate. A total of 11 articles were included in the present analysis, with variable numbers of studies assessing each outcome measure. Results of statistical analyses indicated that progesterone plus estrogen treatment was more likely to result in clinical pregnancy than progesterone alone (pooled odds ratio 1.617, 95% confidence interval 1.059-2.471; P = 0.026). No significant difference between the 2 treatment regimens was found for the other outcome measures. Progesterone plus estrogen for luteal phase support is associated with a higher clinical pregnancy rate than progesterone alone in women undergoing IVF, but other outcomes such as ongoing pregnancy rate, fertilization rate, implantation rate, and miscarriage rate are the same for both treatments.
Goodman, Michael; Squibb, Katherine; Youngstrom, Eric; Anthony, Laura Gutermuth; Kenworthy, Lauren; Lipkin, Paul H; Mattison, Donald R; Lakind, Judy S
2010-06-01
Epidemiologic weight-of-evidence reviews to support regulatory decision making regarding the association between environmental chemical exposures and neurodevelopmental outcomes in children are often complicated by lack of consistency across studies. We examined prospective cohort studies evaluating the relation between prenatal and neonatal exposure to polychlorinated biphenyls (PCBs) and neurodevelopment in children to assess the feasibility of conducting a meta-analysis to support decision making. We described studies in terms of exposure and end point categorization, statistical analysis, and reporting of results. We used this evaluation to assess the feasibility of grouping studies into reasonably uniform categories. The current literature includes 11 cohorts of children for whom effects from prenatal or neonatal PCB exposures were assessed. The most consistently used tests included Brazelton's Neonatal Behavioral Assessment Scale, the neurologic optimality score in the neonatal period, the Bayley Scales of Infant Development at 5-8 months of age, and the McCarthy Scales of Children's Abilities in 5-year-olds. Despite administering the same tests at similar ages, the studies were too dissimilar to allow a meaningful quantitative examination of outcomes across cohorts. These analyses indicate that our ability to conduct weight-of-evidence assessments of the epidemiologic literature on neurotoxicants may be limited, even in the presence of multiple studies, if the available study methods, data analysis, and reporting lack comparability. Our findings add support to previous calls for establishing consensus standards for the conduct, analysis, and reporting of epidemiologic studies in general, and for those evaluating the effects of potential neurotoxic exposures in particular.
A Culture Conducive to Women’s Academic Success: Development of a Measure
Westring, Alyssa Friede; Speck, Rebecca M.; Sammel, Mary Dupuis; Scott, Patricia; Tuton, Lucy Wolf; Grisso, Jeane Ann; Abbuhl, Stephanie
2012-01-01
Purpose The culture of the work environment inhibits women’s career success in academic medicine. The lack of clarity and consistency in the definition, measurement, and analysis of culture constrains current research on the topic. The authors addressed this gap by defining the construct of a culture conducive to women’s academic success (CCWAS) and creating a measure (i.e., tool) to evaluate it. Method First, the authors conducted a review of published literature, held focus groups, and consulted with subject matter experts to develop a measure of academic workplace culture for women. Then they developed and pilot-tested the measure with a convenience sample of women assistant professors. After refining the measure, they administered it, along with additional scales for validation, to 133 women assistant professors at the University of Pennsylvania. Finally, they conducted statistical analyses to explore the measure’s nature and validity. Results A CCWAS consists of four distinct, but related dimensions: equal access, work-life balance, freedom from gender biases, and supportive leadership. The authors found evidence that women within departments/divisions agree on the supportiveness of their units but that substantial differences among units exist. The analyses provided strong evidence for the reliability and validity of their measure. Conclusions This report contributes to a growing understanding of women’s academic medicine careers and provides a measure that researchers can utilize to assess the supportiveness of the culture for women assistant professors and that leaders can use to evaluate the effectiveness of interventions designed to increase the supportiveness of the environment for women faculty. PMID:23018337
Statistical field theory of futures commodity prices
NASA Astrophysics Data System (ADS)
Baaquie, Belal E.; Yu, Miao
2018-02-01
The statistical theory of commodity prices has been formulated by Baaquie (2013). Further empirical studies of single (Baaquie et al., 2015) and multiple commodity prices (Baaquie et al., 2016) have provided strong evidence in support the primary assumptions of the statistical formulation. In this paper, the model for spot prices (Baaquie, 2013) is extended to model futures commodity prices using a statistical field theory of futures commodity prices. The futures prices are modeled as a two dimensional statistical field and a nonlinear Lagrangian is postulated. Empirical studies provide clear evidence in support of the model, with many nontrivial features of the model finding unexpected support from market data.
Prevalence of peri-implantitis in patients with implant-supported fixed prostheses.
Schuldt Filho, Guenther; Dalago, Haline Renata; Oliveira de Souza, João Gustavo; Stanley, Kyle; Jovanovic, Sascha; Bianchini, Marco Aurélio
2014-01-01
The purpose of this study was to evaluate periimplantitis prevalence in patients using implant-supported fixed prostheses that did not have any routine maintenance care. A total of 161 implants (27 patients) were evaluated in patients using implant-supported fixed prostheses. Collected data included information related to patient general health and local factors such as characteristics of implants, time in function, type of loading, positioning, Modified Bleeding Index, bacterial plaque, bleeding on probing (BOP), marginal recession, probing depth (PD), keratinized mucosa, and radiographic bone loss (BL). Factors related to the prostheses were also evaluated. The exclusion criteria were patients that have had any follow-up visit for plaque control of the prosthesis and/or the implants. From a total of 161 implants, 116 (72%) presented without peri-implantitis (PD > 4 mm + BOP + BL > 2 mm) while 45 (28%) had some sign of the disease. Implants placed in the maxilla were 2.98 times more likely to develop the disease (P < .05). Moreover, patients aged ≤ 60 years old were 3.24 times more likely to develop peri-implantitis (P < .05). Another analysis with statistical relevance (P < .05) was that implants with less than 3 mm interimplant distance were three times more likely to have peri-implantitis. There was no statistical relevance considering other analyses. It can be concluded that patients aged ≤ 60 years have a greater chance of presenting periimplantitis, as well as for implants positioned in the maxilla and those placed with an interimplant distance < 3 mm.
Li, Xing-Ming; Yuan, Xiao-Qing; Wang, Jun-Jie; Zhang, Wan-Ying; Zhou, Yang; Liu, Gu-Ning
2017-02-01
Our study was conducted to further investigate the model of social support and care for People Living with HIV/AIDS(PLHA), to explore their role in People Living with AIDS's quality of life (QOL) as reference for improving nursing policies for AIDS. Social support and care are the most important factors impacting the QOL of People Living with HIV/AIDS, but most studies conducted upon the influence of social support and QOL of People Living with HIV/AIDS are mainly based on cross-sectional design. Our study was a nonrandomised controlled community intervention study. The participants diagnosed as People Living with HIV/AIDS at Beijing You An Hospital received a comprehensive social support care from December 2013 to December 2014. To evaluate the impact of social support and care model on People Living with HIV/AIDS, our study analysed the different dimension scores of social support scale and quality of life before and after the intervention. Correlation between the net benefit value of social support and that of QOL from various dimensions were analysed. There were significant differences in the score of objective support and usage of support (all p = 0·02) for social support. Net values of objective support score and usage of support were 0·25 and 0·19, respectively, after intervention. There were significant differences in physiological function, role physical, general health, vitality, social function, mental health, health transition and total score of quality of life (all p < 0·05). The canonical correlation analysis of net values of social support and QOL indicated that the first and second canonical correlation were statistically significant, with correlation coefficients of 0·53 (p = 0·00) and 0·21 (p = 0·04). Social support and care intervention model can effectively improve perceived subjective feeling on social support and QOL condition for People Living with HIV/AIDS. And strategies to improve social support and care intervention programmes are strongly encouraged. The method is simple and cost-effective and could be a way to improve the quality of life condition for People Living with HIV/AIDS. © 2016 John Wiley & Sons Ltd.
A d-statistic for single-case designs that is equivalent to the usual between-groups d-statistic.
Shadish, William R; Hedges, Larry V; Pustejovsky, James E; Boyajian, Jonathan G; Sullivan, Kristynn J; Andrade, Alma; Barrientos, Jeannette L
2014-01-01
We describe a standardised mean difference statistic (d) for single-case designs that is equivalent to the usual d in between-groups experiments. We show how it can be used to summarise treatment effects over cases within a study, to do power analyses in planning new studies and grant proposals, and to meta-analyse effects across studies of the same question. We discuss limitations of this d-statistic, and possible remedies to them. Even so, this d-statistic is better founded statistically than other effect size measures for single-case design, and unlike many general linear model approaches such as multilevel modelling or generalised additive models, it produces a standardised effect size that can be integrated over studies with different outcome measures. SPSS macros for both effect size computation and power analysis are available.
The care unit in nursing home research: evidence in support of a definition.
Estabrooks, Carole A; Morgan, Debra G; Squires, Janet E; Boström, Anne-Marie; Slaughter, Susan E; Cummings, Greta G; Norton, Peter G
2011-04-14
Defining what constitutes a resident care unit in nursing home research is both a conceptual and practical challenge. The aim of this paper is to provide evidence in support of a definition of care unit in nursing homes by demonstrating: (1) its feasibility for use in data collection, (2) the acceptability of aggregating individual responses to the unit level, and (3) the benefit of including unit level data in explanatory models. An observational study design was used. Research (project) managers, healthcare aides, care managers, nursing home administrators and directors of care from thirty-six nursing homes in the Canadian prairie provinces of Alberta, Saskatchewan and Manitoba provided data for the study. A definition of care unit was developed and applied in data collection and analyses. A debriefing session was held with research managers to investigate their experiences with using the care unit definition. In addition, survey responses from 1258 healthcare aides in 25 of the 36 nursing homes in the study, that had more than one care unit, were analyzed using a multi-level modeling approach. Trained field workers administered the Alberta Context Tool (ACT), a 58-item self-report survey reflecting 10 organizational context concepts, to healthcare aides using computer assisted personal interviews. To assess the appropriateness of obtaining unit level scores, we assessed aggregation statistics (ICC(1), ICC(2), η², and ω²), and to assess the value of using the definition of unit in explanatory models, we performed multi-level modeling. In 10 of the 36 nursing homes, the care unit definition developed was used to align the survey data (for analytic purposes) to specific care units as designated by our definition, from that reported by the facility administrator. The aggregation statistics supported aggregating the healthcare aide responses on the ACT to the realigned unit level. Findings from the multi-level modeling further supported unit level aggregation. A significantly higher percentage of variance was explained in the ACT concepts at the unit level compared to the individual and/or nursing home levels. The statistical results support the use of our definition of care unit in nursing home research in the Canadian prairie provinces. Beyond research convenience however, the results also support the resident unit as an important Clinical Microsystem to which future interventions designed to improve resident quality of care and staff (healthcare aide) worklife should be targeted.
ERIC Educational Resources Information Center
LeMire, Steven D.
2010-01-01
This paper proposes an argument framework for the teaching of null hypothesis statistical testing and its application in support of research. Elements of the Toulmin (1958) model of argument are used to illustrate the use of p values and Type I and Type II error rates in support of claims about statistical parameters and subject matter research…
NASA Technical Reports Server (NTRS)
Gilkey, Kelly M.; Myers, Jerry G.; McRae, Michael P.; Griffin, Elise A.; Kallrui, Aditya S.
2012-01-01
The Exploration Medical Capability project is creating a catalog of risk assessments using the Integrated Medical Model (IMM). The IMM is a software-based system intended to assist mission planners in preparing for spaceflight missions by helping them to make informed decisions about medical preparations and supplies needed for combating and treating various medical events using Probabilistic Risk Assessment. The objective is to use statistical analyses to inform the IMM decision tool with estimated probabilities of medical events occurring during an exploration mission. Because data regarding astronaut health are limited, Bayesian statistical analysis is used. Bayesian inference combines prior knowledge, such as data from the general U.S. population, the U.S. Submarine Force, or the analog astronaut population located at the NASA Johnson Space Center, with observed data for the medical condition of interest. The posterior results reflect the best evidence for specific medical events occurring in flight. Bayes theorem provides a formal mechanism for combining available observed data with data from similar studies to support the quantification process. The IMM team performed Bayesian updates on the following medical events: angina, appendicitis, atrial fibrillation, atrial flutter, dental abscess, dental caries, dental periodontal disease, gallstone disease, herpes zoster, renal stones, seizure, and stroke.
ERIC Educational Resources Information Center
Thompson, Bruce; Melancon, Janet G.
Effect sizes have been increasingly emphasized in research as more researchers have recognized that: (1) all parametric analyses (t-tests, analyses of variance, etc.) are correlational; (2) effect sizes have played an important role in meta-analytic work; and (3) statistical significance testing is limited in its capacity to inform scientific…
Comments on `A Cautionary Note on the Interpretation of EOFs'.
NASA Astrophysics Data System (ADS)
Behera, Swadhin K.; Rao, Suryachandra A.; Saji, Hameed N.; Yamagata, Toshio
2003-04-01
The misleading aspect of the statistical analyses used in Dommenget and Latif, which raises concerns on some of the reported climate modes, is demonstrated. Adopting simple statistical techniques, the physical existence of the Indian Ocean dipole mode is shown and then the limitations of varimax and regression analyses in capturing the climate mode are discussed.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dong, Lihua; Cui, Jingkun; Tang, Fengjiao
Purpose: Studies of the association between ataxia telangiectasia–mutated (ATM) gene polymorphisms and acute radiation injuries are often small in sample size, and the results are inconsistent. We conducted the first meta-analysis to provide a systematic review of published findings. Methods and Materials: Publications were identified by searching PubMed up to April 25, 2014. Primary meta-analysis was performed for all acute radiation injuries, and subgroup meta-analyses were based on clinical endpoint. The influence of sample size and radiation injury incidence on genetic effects was estimated in sensitivity analyses. Power calculations were also conducted. Results: The meta-analysis was conducted on the ATMmore » polymorphism rs1801516, including 5 studies with 1588 participants. For all studies, the cut-off for differentiating cases from controls was grade 2 acute radiation injuries. The primary meta-analysis showed a significant association with overall acute radiation injuries (allelic model: odds ratio = 1.33, 95% confidence interval: 1.04-1.71). Subgroup analyses detected an association between the rs1801516 polymorphism and a significant increase in urinary and lower gastrointestinal injuries and an increase in skin injury that was not statistically significant. There was no between-study heterogeneity in any meta-analyses. In the sensitivity analyses, small studies did not show larger effects than large studies. In addition, studies with high incidence of acute radiation injuries showed larger effects than studies with low incidence. Power calculations revealed that the statistical power of the primary meta-analysis was borderline, whereas there was adequate power for the subgroup analysis of studies with high incidence of acute radiation injuries. Conclusions: Our meta-analysis showed a consistency of the results from the overall and subgroup analyses. We also showed that the genetic effect of the rs1801516 polymorphism on acute radiation injuries was dependent on the incidence of the injury. These support the evidence of an association between the rs1801516 polymorphism and acute radiation injuries, encouraging further research of this topic.« less
Waits, L P; Sullivan, J; O'Brien, S J; Ward, R H
1999-10-01
The bear family (Ursidae) presents a number of phylogenetic ambiguities as the evolutionary relationships of the six youngest members (ursine bears) are largely unresolved. Recent mitochondrial DNA analyses have produced conflicting results with respect to the phylogeny of ursine bears. In an attempt to resolve these issues, we obtained 1916 nucleotides of mitochondrial DNA sequence data from six gene segments for all eight bear species and conducted maximum likelihood and maximum parsimony analyses on all fragments separately and combined. All six single-region gene trees gave different phylogenetic estimates; however, only for control region data was this significantly incongruent with the results from the combined data. The optimal phylogeny for the combined data set suggests that the giant panda is most basal followed by the spectacled bear. The sloth bear is the basal ursine bear, and there is weak support for a sister taxon relationship of the American and Asiatic black bears. The sun bear is sister taxon to the youngest clade containing brown bears and polar bears. Statistical analyses of alternate hypotheses revealed a lack of strong support for many of the relationships. We suggest that the difficulties surrounding the resolution of the evolutionary relationships of the Ursidae are linked to the existence of sequential rapid radiation events in bear evolution. Thus, unresolved branching orders during these time periods may represent an accurate representation of the evolutionary history of bear species. Copyright 1999 Academic Press.
Li, Jie; Stroebe, Magaret; Chan, Cecilia L W; Chow, Amy Y M
2017-06-01
The rationale, development, and validation of the Bereavement Guilt Scale (BGS) are described in this article. The BGS was based on a theoretically developed, multidimensional conceptualization of guilt. Part 1 describes the generation of the item pool, derived from in-depth interviews, and review of the scientific literature. Part 2 details statistical analyses for further item selection (Sample 1, N = 273). Part 3 covers the psychometric properties of the emergent-BGS (Sample 2, N = 600, and Sample 3, N = 479). Confirmatory factor analysis indicated that a five-factor model fit the data best. Correlations of BGS scores with depression, anxiety, self-esteem, self-forgiveness, and mode of death were consistent with theoretical predictions, supporting the construct validity of the measure. The internal consistency and test-retest reliability were also supported. Thus, initial testing or examination suggests that the BGS is a valid tool to assess multiple components of bereavement guilt. Further psychometric testing across cultures is recommended.
NASA Astrophysics Data System (ADS)
Li, Peizhen; Tian, Yueli; Zhai, Honglin; Deng, Fangfang; Xie, Meihong; Zhang, Xiaoyun
2013-11-01
Non-purine derivatives have been shown to be promising novel drug candidates as xanthine oxidase inhibitors. Based on three-dimensional quantitative structure-activity relationship (3D-QSAR) methods including comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA), two 3D-QSAR models for a series of non-purine xanthine oxidase (XO) inhibitors were established, and their reliability was supported by statistical parameters. Combined 3D-QSAR modeling and the results of molecular docking between non-purine xanthine oxidase inhibitors and XO, the main factors that influenced activity of inhibitors were investigated, and the obtained results could explain known experimental facts. Furthermore, several new potential inhibitors with higher activity predicted were designed, which based on our analyses, and were supported by the simulation of molecular docking. This study provided some useful information for the development of non-purine xanthine oxidase inhibitors with novel structures.
Factorial invariance of posttraumatic stress disorder symptoms across three veteran samples.
McDonald, Scott D; Beckham, Jean C; Morey, Rajendra; Marx, Christine; Tupler, Larry A; Calhoun, Patrick S
2008-06-01
Research generally supports a 4-factor structure of posttraumatic stress disorder (PTSD) symptoms. However, few studies have established factor invariance by comparing multiple groups. This study examined PTSD symptom structure using the Davidson Trauma Scale (DTS) across three veteran samples: treatment-seeking Vietnam-era veterans, treatment-seeking post-Vietnam-era veterans, and Operation Enduring Freedom/Operation Iraqi Freedom (OEF/OIF) veteran research participants. Confirmatory factor analyses of DTS items demonstrated that a 4-factor structural model of the DTS (reexperiencing, avoidance, numbing, and hyperarousal) was superior to five alternate models, including the conventional 3-factor model proposed by the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV; American Psychiatric Association, 1994). Results supported factor invariance across the three veteran cohorts, suggesting that cross-group comparisons are interpretable. Implications and applications for DSM-IV nosology and the validity of symptom measures are discussed.
A Business Analytics Software Tool for Monitoring and Predicting Radiology Throughput Performance.
Jones, Stephen; Cournane, Seán; Sheehy, Niall; Hederman, Lucy
2016-12-01
Business analytics (BA) is increasingly being utilised by radiology departments to analyse and present data. It encompasses statistical analysis, forecasting and predictive modelling and is used as an umbrella term for decision support and business intelligence systems. The primary aim of this study was to determine whether utilising BA technologies could contribute towards improved decision support and resource management within radiology departments. A set of information technology requirements were identified with key stakeholders, and a prototype BA software tool was designed, developed and implemented. A qualitative evaluation of the tool was carried out through a series of semi-structured interviews with key stakeholders. Feedback was collated, and emergent themes were identified. The results indicated that BA software applications can provide visibility of radiology performance data across all time horizons. The study demonstrated that the tool could potentially assist with improving operational efficiencies and management of radiology resources.
Barbie, Dana L.; Wehmeyer, Loren L.
2012-01-01
Trends in selected streamflow statistics during 1922-2009 were evaluated at 19 long-term streamflow-gaging stations considered indicative of outflows from Texas to Arkansas, Louisiana, Galveston Bay, and the Gulf of Mexico. The U.S. Geological Survey, in cooperation with the Texas Water Development Board, evaluated streamflow data from streamflow-gaging stations with more than 50 years of record that were active as of 2009. The outflows into Arkansas and Louisiana were represented by 3 streamflow-gaging stations, and outflows into the Gulf of Mexico, including Galveston Bay, were represented by 16 streamflow-gaging stations. Monotonic trend analyses were done using the following three streamflow statistics generated from daily mean values of streamflow: (1) annual mean daily discharge, (2) annual maximum daily discharge, and (3) annual minimum daily discharge. The trend analyses were based on the nonparametric Kendall's Tau test, which is useful for the detection of monotonic upward or downward trends with time. A total of 69 trend analyses by Kendall's Tau were computed - 19 periods of streamflow multiplied by the 3 streamflow statistics plus 12 additional trend analyses because the periods of record for 2 streamflow-gaging stations were divided into periods representing pre- and post-reservoir impoundment. Unless otherwise described, each trend analysis used the entire period of record for each streamflow-gaging station. The monotonic trend analysis detected 11 statistically significant downward trends, 37 instances of no trend, and 21 statistically significant upward trends. One general region studied, which seemingly has relatively more upward trends for many of the streamflow statistics analyzed, includes the rivers and associated creeks and bayous to Galveston Bay in the Houston metropolitan area. Lastly, the most western river basins considered (the Nueces and Rio Grande) had statistically significant downward trends for many of the streamflow statistics analyzed.
Kwan, Mun Yee; Gordon, Kathryn H
2016-02-01
The stress generation hypothesis posits that individuals with psychopathology engage in maladaptive behaviors that create stress. Although extensively researched in the depression literature, few studies have investigated whether the stress generation hypothesis applies to eating disorders. This study examined whether bulimic symptoms and dietary restraint predict future life hassles and low social support among undergraduate students. Three hundred seventy-four undergraduate students participated in this two-part prospective study through a secure online system. They completed questionnaires assessing depressive symptoms, bulimic symptoms, dietary restraint, life hassles, and social support. Regression analyses revealed that baseline bulimic symptoms predicted greater life hassles but not lower social support one month later, after statistically controlling for baseline measures. Baseline dietary restraint did not predict future life hassles or social support. Limitations include use of self-report measures, suboptimal response rates at the follow-up assessment, and use of a non-clinical sample with primarily White participants. These results provide preliminary support for the stress generation hypothesis in relation to bulimic symptoms. Individuals with bulimic symptoms may generate stressors similar to those experiencing depressive symptoms. Our findings suggest that emphasizing stress management in the treatment of individuals with bulimic symptoms could potentially improve treatment outcomes. Copyright © 2015 Elsevier B.V. All rights reserved.
NASA Technical Reports Server (NTRS)
Dominick, Wayne D. (Editor); Bassari, Jinous; Triantafyllopoulos, Spiros
1984-01-01
The University of Southwestern Louisiana (USL) NASA PC R and D statistical analysis support package is designed to be a three-level package to allow statistical analysis for a variety of applications within the USL Data Base Management System (DBMS) contract work. The design addresses usage of the statistical facilities as a library package, as an interactive statistical analysis system, and as a batch processing package.
Preliminary testing of flow-ecology hypotheses developed for the GCP LCC region
Brewer, Shannon K.; Davis, Mary
2014-01-01
The Ecological Limits of Hydrological Alteration (ELOHA) framework calls for the development of flow-ecology hypotheses to support protection of the flow regime from ecologically harmful alteration due to human activities. As part of a larger instream flow project for the Gulf Coast Prairie Landscape Conservation Cooperative (GCP LCC), regional flow-ecology hypotheses were developed for fish, mussels, birds, and riparian vegetation (Davis and Brewer 20141). The objective of this study was to assess the usefulness of existing ecological and hydrological data to test these hypotheses or others that may be developed in the future. Several databases related to biological collections and hydrologic data from Oklahoma, Texas, and Louisiana were compiled. State fish-community data from Oklahoma and Louisiana were summarized and paired with existing USGS gage data having at least a 40-year period of record that could be separated into reference and current conditions for comparison. The objective of this study was not to conduct exhaustive analyses of these data, the hypotheses, or analyses interpretation, but rather to use these data to determine if existing data were adequate to statistically test the regional flow-ecology hypotheses. The regional flow-ecology hypotheses were developed for the GCP LCC by a committee chaired by Shannon Brewer and Mary Davis (Davis and Brewer 2014). Existing data were useful for informing the hypotheses and suggest support for some hypotheses, but also highlight the need for additional testing and development as some results contradicted hypotheses. Results presented here suggest existing data are adequate to support some flow-ecology hypotheses; however, lack of sampling effort reported with the fish collections and the need for ecoregion-specific analyses suggest more data would be beneficial to analyses in some ecoregions. Additional fish sampling data from Texas and Louisiana will be available for future analyses and may ameliorate some of the data concerns and improve hypothesis interpretation. If the regional hydrologic model currently under development by the U.S. Geological Survey for the South-Central Climate Science Center is improved to produce daily hydrographs, it will enable use of fish data at ungaged locations. In future efforts, exhaustive analyses using these data, in addition to the development of more complex multivariate hypotheses, would be beneficial to understanding data gaps, particularly as relevant to species of conservation concern.
Taconnat, Laurence; Baudouin, Alexia; Fay, Severine; Raz, Naftali; Bouazzaoui, Badiaa; El-Hage, Wissam; Isingrini, Michel; Ergis, Anne-Marie
2010-08-01
Executive functioning and memory impairment have been demonstrated in adults with depression. Executive functions and memory are related, mainly when the memory tasks require controlled processes (attentional resource demanding processes)--that is, when a low cognitive support (external aid) is provided. A cross-sectional study was carried out on 45 participants: 21 with depression, and 24 healthy controls matched for age, verbal ability, education level, and anxiety score. Cognitive support was manipulated by providing a categorized word list at encoding, presented either clustered (high cognitive support) or randomized (low cognitive support) to both depressed and healthy adults. The number of words recalled was calculated, and an index of clustering was computed to assess organizational strategies. Participants were also administered cognitive tests (executive functions, cognitive speed, and categorical fluency) to explore the mediators of organizational strategies. Depressed participants had greater difficulty recalling and organizing the words, but the differences between the two groups were reduced for both measures when high cognitive support was provided at encoding. Healthy adults performed better on all cognitive tests. Statistical analyses revealed that in the depressed group, executive functions were the only variable associated with clustering and only when low cognitive support was provided. These findings support the view that the decrement in executive function due to depression may lead to impairment in organization when this mnemonic strategy has to be self-initiated.
Medical students' attitudes towards science and gross anatomy, and the relationship to personality
Plaisant, Odile; Stephens, Shiby; Apaydin, Nihal; Courtois, Robert; Lignier, Baptiste; Loukas, Marios; Moxham, Bernard
2014-01-01
Assessment of the personalities of medical students can enable medical educators to formulate strategies for the best development of academic and clinical competencies. Previous research has shown that medical students do not share a common personality profile, there being gender differences. We have also shown that, for French medical students, students with personality traits associated with strong competitiveness are selected for admission to medical school. In this study, we further show that the medical students have different personality profiles compared with other student groups (psychology and business studies). The main purpose of the present investigation was to assess attitudes to science and gross anatomy, and to relate these to the students' personalities. Questionnaires (including Thurstone and Chave analyses) were employed to measure attitudes, and personality was assessed using the Big Five Inventory (BFI). Data for attitudes were obtained for students at medical schools in Cardiff (UK), Paris, Descartes/Sorbonne (France), St George's University (Grenada) and Ankara (Turkey). Data obtained from personality tests were available for analysis from the Parisian cohort of students. Although the medical students were found to have strongly supportive views concerning the importance of science in medicine, their knowledge of the scientific method/philosophy of science was poor. Following analyses of the BFI in the French students, ‘openness’ and ‘conscientiousness’ were linked statistically with a positive attitude towards science. For anatomy, again strongly supportive views concerning the subject's importance in medicine were discerned. Analyses of the BFI in the French students did not show links statistically between personality profiles and attitudes towards gross anatomy, except male students with ‘negative affectivity’ showed less appreciation of the importance of anatomy. This contrasts with our earlier studies that showed that there is a relationship between the BF dimensions of personality traits and anxiety towards the dissection room experience (at the start of the course, ‘negative emotionality’ was related to an increased level of anxiety). We conclude that medical students agree on the importance to their studies of both science in general and gross anatomy in particular, and that some personality traits relate to their attitudes that could affect clinical competence. PMID:23594196
Medical students' attitudes towards science and gross anatomy, and the relationship to personality.
Plaisant, Odile; Stephens, Shiby; Apaydin, Nihal; Courtois, Robert; Lignier, Baptiste; Loukas, Marios; Moxham, Bernard
2014-03-01
Assessment of the personalities of medical students can enable medical educators to formulate strategies for the best development of academic and clinical competencies. Previous research has shown that medical students do not share a common personality profile, there being gender differences. We have also shown that, for French medical students, students with personality traits associated with strong competitiveness are selected for admission to medical school. In this study, we further show that the medical students have different personality profiles compared with other student groups (psychology and business studies). The main purpose of the present investigation was to assess attitudes to science and gross anatomy, and to relate these to the students' personalities. Questionnaires (including Thurstone and Chave analyses) were employed to measure attitudes, and personality was assessed using the Big Five Inventory (BFI). Data for attitudes were obtained for students at medical schools in Cardiff (UK), Paris, Descartes/Sorbonne (France), St George's University (Grenada) and Ankara (Turkey). Data obtained from personality tests were available for analysis from the Parisian cohort of students. Although the medical students were found to have strongly supportive views concerning the importance of science in medicine, their knowledge of the scientific method/philosophy of science was poor. Following analyses of the BFI in the French students, 'openness' and 'conscientiousness' were linked statistically with a positive attitude towards science. For anatomy, again strongly supportive views concerning the subject's importance in medicine were discerned. Analyses of the BFI in the French students did not show links statistically between personality profiles and attitudes towards gross anatomy, except male students with 'negative affectivity' showed less appreciation of the importance of anatomy. This contrasts with our earlier studies that showed that there is a relationship between the BF dimensions of personality traits and anxiety towards the dissection room experience (at the start of the course, 'negative emotionality' was related to an increased level of anxiety). We conclude that medical students agree on the importance to their studies of both science in general and gross anatomy in particular, and that some personality traits relate to their attitudes that could affect clinical competence. © 2013 Anatomical Society.
Hoert, Jennifer; Herd, Ann M; Hambrick, Marion
2018-05-01
The purpose of the study was to explore the relationship between leadership support for health promotion and job stress, wellness program participation, and health behaviors. A cross-sectional survey design was used. Four worksites with a range of wellness programs were selected for this study. Participants in this study were employees (n = 618) at 4 organizations (bank, private university, wholesale supplier, and public university) in the southeastern United States, each offering an employee wellness program. Response rates in each organization ranged from 3% to 34%. Leadership support for health promotion was measured with the Leading by Example instrument. Employee participation in wellness activities, job stress, and health behaviors were measured with multi-item scales. Correlation/regression analysis and descriptive statistics were used to analyze the relationships among the scaled variables. Employees reporting higher levels of leadership support for health promotion also reported higher levels of wellness activity participation, lower job stress, and greater levels of health behavior ( P = .001). To ascertain the amount of variance in health behaviors accounted for by the other variables in the study, a hierarchical regression analysis revealed a statistically significant model (model F 7,523 = 27.28; P = .001), with leadership support for health promotion (β = .19, t = 4.39, P = .001), wellness activity participation (β = .28, t = 6.95, P < .001), and job stress (β = -.27, t = -6.75, P ≤ .001) found to be significant predictors of health behaviors in the model. Exploratory regression analyses by organization revealed the focal variables as significant model predictors for only the 2 larger organizations with well-established wellness programs. Results from the study suggest that employees' perceptions of organizational leadership support for health promotion are related to their participation in wellness activities, perceived job stress levels, and health behaviors.
Social support and medication adherence in HIV disease in KwaZulu-Natal, South Africa.
Ncama, Busisiwe P; McInerney, Patricia A; Bhengu, Busisiwe R; Corless, Inge B; Wantland, Dean J; Nicholas, Patrice K; McGibbon, Chris A; Davis, Sheila M
2008-12-01
A supportive social environment is critical for those with HIV/AIDS. In KwaZulu-Natal, in South Africa, antiretroviral therapy is available to some HIV-positive individuals. Antiretroviral adherence is an important issue for limiting HIV infection. Adherence to therapy may be linked to social support, particularly amidst the stigma prevalent in HIV. The purpose of this study was to examine characteristics related to social support and antiretroviral medication adherence. This cross-sectional, descriptive study explored the nature of the relationships among social support and other selected variables, including sociodemographic variables, quality of life, and adherence. After ethical review board approval, the sample of HIV-infected individuals who received care in outpatient clinics were recruited and completed the self-report instruments. The sample included English and/or isiZulu-speaking (n=149) individuals over the age of 18 years receiving treatment for HIV/AIDS. A total of 149 patients with a diagnosis of HIV/AIDS agreed to participate and completed questionnaires after completing informed consent procedures. The study participants were recruited at four outpatient settings in Durban, KwaZulu-Natal province of South Africa. A descriptive, exploratory, cross-sectional design was utilized to explore the research questions: What are the characteristics of social support and the relationship to antiretroviral adherence in KwaZulu-Natal, South Africa? Descriptive statistics and regression analyses were used to answer the research questions. Data analyses indicated that social support scores on the Medical Outcomes Study Social Support Survey were moderate (M=64.4; S.D.=14.7) among the study participants. The number of close friends and family were significantly correlated with a greater sense of social support. Despite this, the lowest scores on the quality-of-life measure using the Medical Outcomes Study Short Form 36 item survey were reported on the Social Functioning Scale. In summary, the study findings suggest that a supportive social network is essential for those living with HIV/AIDS. However, social functioning and quality of life amidst the stigma of living with HIV in South Africa may be a concern and require further investigation.
Searching Choices: Quantifying Decision-Making Processes Using Search Engine Data.
Moat, Helen Susannah; Olivola, Christopher Y; Chater, Nick; Preis, Tobias
2016-07-01
When making a decision, humans consider two types of information: information they have acquired through their prior experience of the world, and further information they gather to support the decision in question. Here, we present evidence that data from search engines such as Google can help us model both sources of information. We show that statistics from search engines on the frequency of content on the Internet can help us estimate the statistical structure of prior experience; and, specifically, we outline how such statistics can inform psychological theories concerning the valuation of human lives, or choices involving delayed outcomes. Turning to information gathering, we show that search query data might help measure human information gathering, and it may predict subsequent decisions. Such data enable us to compare information gathered across nations, where analyses suggest, for example, a greater focus on the future in countries with a higher per capita GDP. We conclude that search engine data constitute a valuable new resource for cognitive scientists, offering a fascinating new tool for understanding the human decision-making process. Copyright © 2016 The Authors. Topics in Cognitive Science published by Wiley Periodicals, Inc. on behalf of Cognitive Science Society.
Patterson, Megan S; Goodson, Patricia
2017-05-01
Compulsive exercise, a form of unhealthy exercise often associated with prioritizing exercise and feeling guilty when exercise is missed, is a common precursor to and symptom of eating disorders. College-aged women are at high risk of exercising compulsively compared with other groups. Social network analysis (SNA) is a theoretical perspective and methodology allowing researchers to observe the effects of relational dynamics on the behaviors of people. SNA was used to assess the relationship between compulsive exercise and body dissatisfaction, physical activity, and network variables. Descriptive statistics were conducted using SPSS, and quadratic assignment procedure (QAP) analyses were conducted using UCINET. QAP regression analysis revealed a statistically significant model (R 2 = .375, P < .0001) predicting compulsive exercise behavior. Physical activity, body dissatisfaction, and network variables were statistically significant predictor variables in the QAP regression model. In our sample, women who are connected to "important" or "powerful" people in their network are likely to have higher compulsive exercise scores. This result provides healthcare practitioners key target points for intervention within similar groups of women. For scholars researching eating disorders and associated behaviors, this study supports looking into group dynamics and network structure in conjunction with body dissatisfaction and exercise frequency.
Papageorgiou, Spyridon N; Kloukos, Dimitrios; Petridis, Haralampos; Pandis, Nikolaos
2015-10-01
To assess the hypothesis that there is excessive reporting of statistically significant studies published in prosthodontic and implantology journals, which could indicate selective publication. The last 30 issues of 9 journals in prosthodontics and implant dentistry were hand-searched for articles with statistical analyses. The percentages of significant and non-significant results were tabulated by parameter of interest. Univariable/multivariable logistic regression analyses were applied to identify possible predictors of reporting statistically significance findings. The results of this study were compared with similar studies in dentistry with random-effects meta-analyses. From the 2323 included studies 71% of them reported statistically significant results, with the significant results ranging from 47% to 86%. Multivariable modeling identified that geographical area and involvement of statistician were predictors of statistically significant results. Compared to interventional studies, the odds that in vitro and observational studies would report statistically significant results was increased by 1.20 times (OR: 2.20, 95% CI: 1.66-2.92) and 0.35 times (OR: 1.35, 95% CI: 1.05-1.73), respectively. The probability of statistically significant results from randomized controlled trials was significantly lower compared to various study designs (difference: 30%, 95% CI: 11-49%). Likewise the probability of statistically significant results in prosthodontics and implant dentistry was lower compared to other dental specialties, but this result did not reach statistical significant (P>0.05). The majority of studies identified in the fields of prosthodontics and implant dentistry presented statistically significant results. The same trend existed in publications of other specialties in dentistry. Copyright © 2015 Elsevier Ltd. All rights reserved.
Wojtalik, Jessica A; Eack, Shaun M; Keshavan, Matcheri S
2013-01-10
The Mayer-Salovey-Caruso Emotional Intelligence Test (MSCEIT) is a key measure of social cognition in schizophrenia that has good psychometric properties and is recommended by the MATRICS committee. As a way to further investigate the validity of the MSCEIT, this study sought to examine the neurobiological correlates of MSCEIT performance in patients with early course schizophrenia. A total of 51 patients diagnosed with early course, stabilized schizophrenia or schizoaffective disorder completed structural magnetic resonance imaging (MRI) scans and the MSCEIT. Investigation of the associations between MSCEIT performance and gray matter morphology was examined by conducting voxel-based morphometry (VBM) analyses across hypothesized social-cognitive regions of interest using automated anatomical labeling in Statistical Parametric Mapping Software, version 5 (SPM5). All VBM analyses utilized general linear models examining gray matter density partitioned images, adjusting for demographic and illness-related confounds. VBM results were then followed up with confirmatory volumetric analyses. Patients with poorer overall and Facilitating, Understanding, and Managing Emotions subscale performances on the MSCEIT showed significantly reduced gray matter density in the left parahippocampal gyrus. Additionally, attenuated performance on the Facilitating and Managing Emotions subscales was significantly associated with reduced right posterior cingulate gray matter density. All associations observed between MSCEIT performance and gray matter density were supported with confirmatory gray matter volumetric analyses, with the exception of the association between the right posterior cingulate and the facilitation of emotions. These findings provide additional evidence for the MSCEIT as a valid social-cognitive measure by elucidating its correlates with neurobiological structures commonly implicated in emotion processing. These findings provide additional biological evidence supporting the use of the MSCEIT in cognitive enhancing clinical trials in schizophrenia. Copyright © 2012 Elsevier Inc. All rights reserved.
2012-01-01
Background Supporting self-care is being explored across health care systems internationally as an approach to improving care for long term conditions in the context of ageing populations and economic constraint. UK health policy advocates a range of approaches to supporting self-care, including the application of generic self-management type programmes across conditions. Within mental health, the scope of self-care remains poorly conceptualised and the existing evidence base for supporting self-care is correspondingly disparate. This paper aims to inform the development of support for self-care in mental health by considering how generic self-care policy guidance is implemented in the context of services supporting people with severe, long term mental health problems. Methods A mixed method study was undertaken comprising standardised psychosocial measures, questionnaires about health service use and qualitative interviews with 120 new referrals to three contrasting community based initiatives supporting self-care for severe, long term mental health problems, repeated nine months later. A framework approach was taken to qualitative analysis, an exploratory statistical analysis sought to identify possible associations between a range of independent variables and self-care outcomes, and a narrative synthesis brought these analyses together. Results Participants reported improvement in self-care outcomes (e.g. greater empowerment; less use of Accident and Emergency services). These changes were not associated with level of engagement with self-care support. Level of engagement was associated with positive collaboration with support staff. Qualitative data described the value of different models of supporting self-care and considered challenges. Synthesis of analyses suggested that timing support for self-care, giving service users control over when and how they accessed support, quality of service user-staff relationships and decision making around medication are important issues in supporting self-care in mental health. Conclusions Service delivery components – e.g. peer support groups, personal planning – advocated in generic self-care policy have value when implemented in a mental health context. Support for self-care in mental health should focus on core, mental health specific qualities; issues of control, enabling staff-service user relationships and shared decision making. The broad empirical basis of our research indicates the wider relevance of our findings across mental health settings. PMID:22769593
A time to be born: Variation in the hour of birth in a rural population of Northern Argentina.
Chaney, Carlye; Goetz, Laura G; Valeggia, Claudia
2018-04-17
The present study aimed at investigating the timing of birth across the day in a rural population of indigenous and nonindigenous women in the province of Formosa, Argentina in order to explore the variation in patterns in a non-Western setting. This study utilized birth record data transcribed from delivery room records at a rural hospital in the province of Formosa, northern Argentina. The sample included data for Criollo, Wichí, and Toba/Qom women (n = 2421). Statistical analysis was conducted using directional statistics to identify a mean sample direction. Chi-square tests for homogeneity were also used to test for statistical significant differences between hours of the day. The mean sample direction was 81.04°, which equates to 5:24 AM when calculated as time on a 24-hr clock. Chi-squared analyses showed a statistically significant peak in births between 12:00 and 4:00 AM. Birth counts generally declined throughout the day until a statistically significant trough around 5:00 PM. This pattern may be associated with the circadian rhythms of hormone release, particularly melatonin, on a proximate level. At the ultimate level, giving birth in the early hours of the morning may have been selected to time births when the mother could benefit from the predator protection and support provided by her social group as well as increased mother-infant bonding from a more peaceful environment. © 2018 Wiley Periodicals, Inc.
Assessment and statistics of surgically induced astigmatism.
Naeser, Kristian
2008-05-01
The aim of the thesis was to develop methods for assessment of surgically induced astigmatism (SIA) in individual eyes, and in groups of eyes. The thesis is based on 12 peer-reviewed publications, published over a period of 16 years. In these publications older and contemporary literature was reviewed(1). A new method (the polar system) for analysis of SIA was developed. Multivariate statistical analysis of refractive data was described(2-4). Clinical validation studies were performed. The description of a cylinder surface with polar values and differential geometry was compared. The main results were: refractive data in the form of sphere, cylinder and axis may define an individual patient or data set, but are unsuited for mathematical and statistical analyses(1). The polar value system converts net astigmatisms to orthonormal components in dioptric space. A polar value is the difference in meridional power between two orthogonal meridians(5,6). Any pair of polar values, separated by an arch of 45 degrees, characterizes a net astigmatism completely(7). The two polar values represent the net curvital and net torsional power over the chosen meridian(8). The spherical component is described by the spherical equivalent power. Several clinical studies demonstrated the efficiency of multivariate statistical analysis of refractive data(4,9-11). Polar values and formal differential geometry describe astigmatic surfaces with similar concepts and mathematical functions(8). Other contemporary methods, such as Long's power matrix, Holladay's and Alpins' methods, Zernike(12) and Fourier analyses(8), are correlated to the polar value system. In conclusion, analysis of SIA should be performed with polar values or other contemporary component systems. The study was supported by Statens Sundhedsvidenskabeligt Forskningsråd, Cykelhandler P. Th. Rasmussen og Hustrus Mindelegat, Hotelejer Carl Larsen og Hustru Nicoline Larsens Mindelegat, Landsforeningen til Vaern om Synet, Forskningsinitiativet for Arhus Amt, Alcon Denmark, and Desirée and Niels Ydes Fond.
Comparing Visual and Statistical Analysis of Multiple Baseline Design Graphs.
Wolfe, Katie; Dickenson, Tammiee S; Miller, Bridget; McGrath, Kathleen V
2018-04-01
A growing number of statistical analyses are being developed for single-case research. One important factor in evaluating these methods is the extent to which each corresponds to visual analysis. Few studies have compared statistical and visual analysis, and information about more recently developed statistics is scarce. Therefore, our purpose was to evaluate the agreement between visual analysis and four statistical analyses: improvement rate difference (IRD); Tau-U; Hedges, Pustejovsky, Shadish (HPS) effect size; and between-case standardized mean difference (BC-SMD). Results indicate that IRD and BC-SMD had the strongest overall agreement with visual analysis. Although Tau-U had strong agreement with visual analysis on raw values, it had poorer agreement when those values were dichotomized to represent the presence or absence of a functional relation. Overall, visual analysis appeared to be more conservative than statistical analysis, but further research is needed to evaluate the nature of these disagreements.
Industry guidelines, laws and regulations ignored: quality of drug advertising in medical journals.
Lankinen, Kari S; Levola, Tero; Marttinen, Kati; Puumalainen, Inka; Helin-Salmivaara, Arja
2004-11-01
To document the quality of evidence base for marketing claims in prescription drug advertisements, to facilitate identification of potential targets for quality improvement. A sample of 1036 advertisements from four major Finnish medical journals published in 2002. Marketing claims were classified in four groups: unambiguous clinical outcome, vague clinical outcome, emotive or immeasurable outcome and non-clinical outcome. Medline references were traced and classified according to the level of evidence available. The statistical variables used in the advertisements were also documented. The sample included 245 distinct advertisements with 883 marketing claims, 1-10 claims per advertisement. Three hundred thirty seven (38%) of the claims were referenced. Each claim could be supported by one reference or more, so the number of references analysed totalled 381, 1-9 references per advertisement. Nine percent of the claims implied unambiguous clinical outcomes, 68% included vague or emotive statements. Twenty one percent of the references were irrelevant to the claim. There was a fair amount of non-scientific and scientific support for the 73 unambiguous claims, but not a single claim was supported by strong scientific evidence. Vague, emotive and non-clinical claims were significantly more often supported by non-Medline or irrelevant references than unambiguous claims. Statistical parameters were stated only 34 times. Referenced marketing claims may appear more scientific, but the use of references does not guarantee the quality of the claims. For the benefit of all stakeholders, both the regulatory control and industry's self-control of drug marketing should adopt more active monitoring roles, and apply sanctions when appropriate. Concerted efforts by several stakeholders might be more effective. Copyright 2004 John Wiley & Sons, Ltd.
USDA-ARS?s Scientific Manuscript database
Agronomic and Environmental research experiments result in data that are analyzed using statistical methods. These data are unavoidably accompanied by uncertainty. Decisions about hypotheses, based on statistical analyses of these data are therefore subject to error. This error is of three types,...
The Large-Scale Structure of Semantic Networks: Statistical Analyses and a Model of Semantic Growth
ERIC Educational Resources Information Center
Steyvers, Mark; Tenenbaum, Joshua B.
2005-01-01
We present statistical analyses of the large-scale structure of 3 types of semantic networks: word associations, WordNet, and Roget's Thesaurus. We show that they have a small-world structure, characterized by sparse connectivity, short average path lengths between words, and strong local clustering. In addition, the distributions of the number of…
Souza, Isys Mascarenhas; Funch, Ligia Silveira; de Queiroz, Luciano Paganucci
2014-01-01
Abstract Hymenaea is a genus of the Resin-producing Clade of the tribe Detarieae (Leguminosae: Caesalpinioideae) with 14 species. Hymenaea courbaril is the most widespread species of the genus, ranging from southern Mexico to southeastern Brazil. As currently circumscribed, Hymenaea courbaril is a polytypic species with six varieties: var. altissima, var. courbaril, var. longifolia, var. stilbocarpa, var. subsessilis, and var. villosa. These varieties are distinguishable mostly by traits related to leaflet shape and indumentation, and calyx indumentation. We carried out morphometric analyses of 14 quantitative (continuous) leaf characters in order to assess the taxonomy of Hymenaea courbaril under the Unified Species Concept framework. Cluster analysis used the Unweighted Pair Group Method with Arithmetic Mean (UPGMA) based on Bray-Curtis dissimilarity matrices. Principal Component Analyses (PCA) were carried out based on the same morphometric matrix. Two sets of Analyses of Similarity and Non Parametric Multivariate Analysis of Variance were carried out to evaluate statistical support (1) for the major groups recovered using UPGMA and PCA, and (2) for the varieties. All analyses recovered three major groups coincident with (1) var. altissima, (2) var. longifolia, and (3) all other varieties. These results, together with geographical and habitat information, were taken as evidence of three separate metapopulation lineages recognized here as three distinct species. Nomenclatural adjustments, including reclassifying formerly misapplied types, are proposed. PMID:25009440
Souza, Isys Mascarenhas; Funch, Ligia Silveira; de Queiroz, Luciano Paganucci
2014-01-01
Hymenaea is a genus of the Resin-producing Clade of the tribe Detarieae (Leguminosae: Caesalpinioideae) with 14 species. Hymenaea courbaril is the most widespread species of the genus, ranging from southern Mexico to southeastern Brazil. As currently circumscribed, Hymenaea courbaril is a polytypic species with six varieties: var. altissima, var. courbaril, var. longifolia, var. stilbocarpa, var. subsessilis, and var. villosa. These varieties are distinguishable mostly by traits related to leaflet shape and indumentation, and calyx indumentation. We carried out morphometric analyses of 14 quantitative (continuous) leaf characters in order to assess the taxonomy of Hymenaea courbaril under the Unified Species Concept framework. Cluster analysis used the Unweighted Pair Group Method with Arithmetic Mean (UPGMA) based on Bray-Curtis dissimilarity matrices. Principal Component Analyses (PCA) were carried out based on the same morphometric matrix. Two sets of Analyses of Similarity and Non Parametric Multivariate Analysis of Variance were carried out to evaluate statistical support (1) for the major groups recovered using UPGMA and PCA, and (2) for the varieties. All analyses recovered three major groups coincident with (1) var. altissima, (2) var. longifolia, and (3) all other varieties. These results, together with geographical and habitat information, were taken as evidence of three separate metapopulation lineages recognized here as three distinct species. Nomenclatural adjustments, including reclassifying formerly misapplied types, are proposed.
Carlson, Jordan A; Sarkin, Andrew J; Levack, Ashley E; Sklar, Marisa; Tally, Steven R; Gilmer, Todd P; Groessl, Erik J
2011-08-01
Social health is important to measure when assessing outcomes in community mental health. Our objective was to validate social health scales using items from two broader commonly used measures that assess mental health outcomes. Participants were 609 adults receiving psychological treatment services. Items were identified from the California Quality of Life (CA-QOL) and Mental Health Statistics Improvement Program (MHSIP) outcome measures by their conceptual correspondence with social health and compared to the Social Functioning Questionnaire (SFQ) using correlational analyses. Pearson correlations for the identified CA-QOL and MSHIP items with the SFQ ranged from .42 to .62, and the identified scale scores produced Pearson correlation coefficients of .56, .70, and, .70 with the SFQ. Concurrent validity with social health was supported for the identified scales. The current inclusion of these assessment tools allows community mental health programs to include social health in their assessments.
Nogueira, Leandro Alberto Calazans; Santos, Luciano Teixeira Dos; Sabino, Pollyane Galinari; Alvarenga, Regina Maria Papais; Thuler, Luiz Claudio Santos
2013-08-01
We analysed the cognitive influence on walking in multiple sclerosis (MS) patients, in the absence of clinical disability. A case-control study was conducted with 12 MS patients with no disability and 12 matched healthy controls. Subjects were referred for completion a timed walk test of 10 m and a 3D-kinematic analysis. Participants were instructed to walk at a comfortable speed in a dual-task (arithmetic task) condition, and motor planning was measured by mental chronometry. Scores of walking speed and cadence showed no statistically significant differences between the groups in the three conditions. The dual-task condition showed an increase in the double support duration in both groups. Motor imagery analysis showed statistically significant differences between real and imagined walking in patients. MS patients with no disability did not show any influence of divided attention on walking execution. However, motor planning was overestimated as compared with real walking.
Assessing knowledge on fibromyalgia among Internet users.
Moretti, Felipe Azevedo; Heymann, Roberto Ezequiel; Marvulle, Valdecir; Pollak, Daniel Feldman; Riera, Rachel
2011-01-01
To assess knowledge on fibromyalgia in a sample of patients, their families, and professionals interested on the theme from some Brazilian states. Analysis of the results of an electronic fibromyalgia knowledge questionnaire completed by 362 adults who had access to the the support group for fibromyalgia site (www.unifesp.br/grupos/fibromialgia). The answers were grouped according to age, sex, years of schooling, and type of interest in the condition. 92% of the responders were women and 62% had higher educational level. The worst results were observed in the "joint protection and energy conservation" domain, followed by the "medication in fibromyalgia" domain. The best results were recorded in the "exercises in fibromyalgia" domain. The answers differed significantly between sexes, and women achieved a higher percentage of correct answers. The female sex accounted for a statistically superior result in five statistical analyses (four questions and one domain). The study suggests the need for a strategic planning for an educational approach to fibromyalgia in Brazil.
NASA Technical Reports Server (NTRS)
Craft, R.; Dunn, C.; Mccord, J.; Simeone, L.
1980-01-01
A user guide and programmer documentation is provided for a system of PRIME 400 minicomputer programs. The system was designed to support loading analyses on the Tracking Data Relay Satellite System (TDRSS). The system is a scheduler for various types of data relays (including tape recorder dumps and real time relays) from orbiting payloads to the TDRSS. Several model options are available to statistically generate data relay requirements. TDRSS time lines (representing resources available for scheduling) and payload/TDRSS acquisition and loss of sight time lines are input to the scheduler from disk. Tabulated output from the interactive system includes a summary of the scheduler activities over time intervals specified by the user and overall summary of scheduler input and output information. A history file, which records every event generated by the scheduler, is written to disk to allow further scheduling on remaining resources and to provide data for graphic displays or additional statistical analysis.
The big-fish-little-pond effect on mathematics self-concept: Evidence from the United Arab Emirates.
Areepattamannil, Shaljan; Khine, Myint Swe; Al Nuaimi, Samira
2017-08-01
This study examined the big-fish-little-pond effect (BFLPE; Marsh, 1987) on mathematics self-concept of 7404 adolescents (female = 3767 [51%], male = 3637 [49%]; M age = 15.85 years, SD = 0.28) from 456 schools in the United Arab Emirates, one of the Arab states of the Persian Gulf. The results of multilevel regression analyses indicated good support for the BFLPE's theoretical predictions: the effect of individual student mathematics achievement on individual student mathematics self-concept was positive and statistically significant, whereas the effect of school-average mathematics achievement on individual student mathematics self-concept was negative and statistically significant. Moreover, the interaction between school-average mathematics achievement and individual student mathematics achievement was small and non-significant. Implications of the findings for policy and practice are briefly discussed. Copyright © 2017 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.
Lee, Sang-Ahm; No, Soon-Kee; Park, Hyungkook; Kim, Ok-Joon; Kwon, Jee-Hyun; Ryu, Ji-Yeon; Lee, Sang-Moo; Jo, Kwang-Deog
2017-09-01
Epilepsy is a concealable stigmatizing condition. We investigated the factors predicting disclosure management behavior in Korean adults with newly diagnosed epilepsy. This longitudinal multicenter study included Korean adults with newly diagnosed epilepsy. Using statistical analyses, we determined at the end of a 1-year follow-up whether Disclosure Management Scale (DMS) scores were predicted by demographic, clinical, and psychosocial variables, including felt stigma, stress coping style, personality traits, social support, and experienced discrimination from society. Of a total of 121 participants, 69% reported that they often or sometimes kept their diagnosis a secret from others and rarely or never talked to others about their epilepsy. The average DMS score was 5.8 (SD=2.9, range 0-11). In univariate analyses, DMS scores were significantly associated with an emotion-focused coping style (r=0.320, p<0.001), social support (r=-0.185, p<0.05), and experienced discrimination (p<0.05). Emotion-focused coping was the only independent predictor of a higher DMS score. Felt stigma, personality traits, and seizure freedom were not related to the DMS score. Two-thirds of Korean adults with newly diagnosed epilepsy often or sometimes keep their epilepsy a secret. Emotion-focused coping is the most important predictor of concealment of epilepsy diagnosis at the end of a 1-year follow-up, although social support and episodes of experienced discrimination are also associated with disclosure management strategies. Copyright © 2017 Elsevier Inc. All rights reserved.
Statistical quality control through overall vibration analysis
NASA Astrophysics Data System (ADS)
Carnero, M. a. Carmen; González-Palma, Rafael; Almorza, David; Mayorga, Pedro; López-Escobar, Carlos
2010-05-01
The present study introduces the concept of statistical quality control in automotive wheel bearings manufacturing processes. Defects on products under analysis can have a direct influence on passengers' safety and comfort. At present, the use of vibration analysis on machine tools for quality control purposes is not very extensive in manufacturing facilities. Noise and vibration are common quality problems in bearings. These failure modes likely occur under certain operating conditions and do not require high vibration amplitudes but relate to certain vibration frequencies. The vibration frequencies are affected by the type of surface problems (chattering) of ball races that are generated through grinding processes. The purpose of this paper is to identify grinding process variables that affect the quality of bearings by using statistical principles in the field of machine tools. In addition, an evaluation of the quality results of the finished parts under different combinations of process variables is assessed. This paper intends to establish the foundations to predict the quality of the products through the analysis of self-induced vibrations during the contact between the grinding wheel and the parts. To achieve this goal, the overall self-induced vibration readings under different combinations of process variables are analysed using statistical tools. The analysis of data and design of experiments follows a classical approach, considering all potential interactions between variables. The analysis of data is conducted through analysis of variance (ANOVA) for data sets that meet normality and homoscedasticity criteria. This paper utilizes different statistical tools to support the conclusions such as chi squared, Shapiro-Wilks, symmetry, Kurtosis, Cochran, Hartlett, and Hartley and Krushal-Wallis. The analysis presented is the starting point to extend the use of predictive techniques (vibration analysis) for quality control. This paper demonstrates the existence of predictive variables (high-frequency vibration displacements) that are sensible to the processes setup and the quality of the products obtained. Based on the result of this overall vibration analysis, a second paper will analyse self-induced vibration spectrums in order to define limit vibration bands, controllable every cycle or connected to permanent vibration-monitoring systems able to adjust sensible process variables identified by ANOVA, once the vibration readings exceed established quality limits.
Differences in Performance Among Test Statistics for Assessing Phylogenomic Model Adequacy.
Duchêne, David A; Duchêne, Sebastian; Ho, Simon Y W
2018-05-18
Statistical phylogenetic analyses of genomic data depend on models of nucleotide or amino acid substitution. The adequacy of these substitution models can be assessed using a number of test statistics, allowing the model to be rejected when it is found to provide a poor description of the evolutionary process. A potentially valuable use of model-adequacy test statistics is to identify when data sets are likely to produce unreliable phylogenetic estimates, but their differences in performance are rarely explored. We performed a comprehensive simulation study to identify test statistics that are sensitive to some of the most commonly cited sources of phylogenetic estimation error. Our results show that, for many test statistics, traditional thresholds for assessing model adequacy can fail to reject the model when the phylogenetic inferences are inaccurate and imprecise. This is particularly problematic when analysing loci that have few variable informative sites. We propose new thresholds for assessing substitution model adequacy and demonstrate their effectiveness in analyses of three phylogenomic data sets. These thresholds lead to frequent rejection of the model for loci that yield topological inferences that are imprecise and are likely to be inaccurate. We also propose the use of a summary statistic that provides a practical assessment of overall model adequacy. Our approach offers a promising means of enhancing model choice in genome-scale data sets, potentially leading to improvements in the reliability of phylogenomic inference.
2014-01-01
Background There is a need for cost-effective weight management interventions that primary care can deliver to reduce the morbidity caused by obesity. Automated web-based interventions might provide a solution, but evidence suggests that they may be ineffective without additional human support. The main aim of this study was to carry out a feasibility trial of a web-based weight management intervention in primary care, comparing different levels of nurse support, to determine the optimal combination of web-based and personal support to be tested in a full trial. Methods This was an individually randomised four arm parallel non-blinded trial, recruiting obese patients in primary care. Following online registration, patients were randomly allocated by the automated intervention to either usual care, the web-based intervention only, or the web-based intervention with either basic nurse support (3 sessions in 3 months) or regular nurse support (7 sessions in 6 months). The main outcome measure (intended as the primary outcome for the main trial) was weight loss in kg at 12 months. As this was a feasibility trial no statistical analyses were carried out, but we present means, confidence intervals and effect sizes for weight loss in each group, uptake and retention, and completion of intervention components and outcome measures. Results All randomised patients were included in the weight loss analyses (using Last Observation Carried Forward). At 12 months mean weight loss was: usual care group (n = 43) 2.44 kg; web-based only group (n = 45) 2.30 kg; basic nurse support group (n = 44) 4.31 kg; regular nurse support group (n = 47) 2.50 kg. Intervention effect sizes compared with usual care were: d = 0.01 web-based; d = 0.34 basic nurse support; d = 0.02 regular nurse support. Two practices deviated from protocol by providing considerable weight management support to their usual care patients. Conclusions This study demonstrated the feasibility of delivering a web-based weight management intervention supported by practice nurses in primary care, and suggests that the combination of the web-based intervention with basic nurse support could provide an effective solution to weight management support in a primary care context. Trial registration Current Controlled Trials ISRCTN31685626. PMID:24886516
Sanson, R L; Gloster, J; Burgin, L
2011-09-24
The aims of this study were to statistically reassess the likelihood that windborne spread of foot-and-mouth disease (FMD) virus (FMDV) occurred at the start of the UK 1967 to 1968 FMD epidemic at Oswestry, Shropshire, and to derive dose-response probability of infection curves for farms exposed to airborne FMDV. To enable this, data on all farms present in 1967 in the parishes near Oswestry were assembled. Cases were infected premises whose date of appearance of first clinical signs was within 14 days of the depopulation of the index farm. Logistic regression was used to evaluate the association between infection status and distance and direction from the index farm. The UK Met Office's NAME atmospheric dispersion model (ADM) was used to generate plumes for each day that FMDV was excreted from the index farm based on actual historical weather records from October 1967. Daily airborne FMDV exposure rates for all farms in the study area were calculated using a geographical information system. Probit analyses were used to calculate dose-response probability of infection curves to FMDV, using relative exposure rates on case and control farms. Both the logistic regression and probit analyses gave strong statistical support to the hypothesis that airborne spread occurred. There was some evidence that incubation period was inversely proportional to the exposure rate.
NASA Astrophysics Data System (ADS)
Rodgers, Mel; Smith, Patrick; Pyle, David; Mather, Tamsin
2016-04-01
Understanding the transition between quiescence and eruption at dome-forming volcanoes, such as Soufrière Hills Volcano (SHV), Montserrat, is important for monitoring volcanic activity during long-lived eruptions. Statistical analysis of seismic events (e.g. spectral analysis and identification of multiplets via cross-correlation) can be useful for characterising seismicity patterns and can be a powerful tool for analysing temporal changes in behaviour. Waveform classification is crucial for volcano monitoring, but consistent classification, both during real-time analysis and for retrospective analysis of previous volcanic activity, remains a challenge. Automated classification allows consistent re-classification of events. We present a machine learning (random forest) approach to rapidly classify waveforms that requires minimal training data. We analyse the seismic precursors to the July 2008 Vulcanian explosion at SHV and show systematic changes in frequency content and multiplet behaviour that had not previously been recognised. These precursory patterns of seismicity may be interpreted as changes in pressure conditions within the conduit during magma ascent and could be linked to magma flow rates. Frequency analysis of the different waveform classes supports the growing consensus that LP and Hybrid events should be considered end members of a continuum of low-frequency source processes. By using both supervised and unsupervised machine-learning methods we investigate the nature of waveform classification and assess current classification schemes.
Reduction of Fasting Blood Glucose and Hemoglobin A1c Using Oral Aloe Vera: A Meta-Analysis.
Dick, William R; Fletcher, Emily A; Shah, Sachin A
2016-06-01
Diabetes mellitus is a global epidemic and one of the leading causes of morbidity and mortality. Additional medications that are novel, affordable, and efficacious are needed to treat this rampant disease. This meta-analysis was performed to ascertain the effectiveness of oral aloe vera consumption on the reduction of fasting blood glucose (FBG) and hemoglobin A1c (HbA1c). PubMed, CINAHL, Natural Medicines Comprehensive Database, and Natural Standard databases were searched. Studies of aloe vera's effect on FBG, HbA1c, homeostasis model assessment-estimated insulin resistance (HOMA-IR), fasting serum insulin, fructosamine, and oral glucose tolerance test (OGTT) in prediabetic and diabetic populations were examined. After data extraction, the parameters of FBG and HbA1c had appropriate data for meta-analyses. Extracted data were verified and then analyzed by StatsDirect Statistical Software. Reductions of FBG and HbA1c were reported as the weighted mean differences from baseline, calculated by a random-effects model with 95% confidence intervals. Subgroup analyses to determine clinical and statistical heterogeneity were also performed. Publication bias was assessed by using the Egger bias statistic. Nine studies were included in the FBG parameter (n = 283); 5 of these studies included HbA1c data (n = 89). Aloe vera decreased FBG by 46.6 mg/dL (p < 0.0001) and HbA1c by 1.05% (p = 0.004). Significant reductions of both endpoints were maintained in all subgroup analyses. Additionally, the data suggest that patients with an FBG ≥200 mg/dL may see a greater benefit. A mean FBG reduction of 109.9 mg/dL was observed in this population (p ≤ 0.0001). The Egger statistic showed publication bias with FBG but not with HbA1c (p = 0.010 and p = 0.602, respectively). These results support the use of oral aloe vera for significantly reducing FBG (46.6 mg/dL) and HbA1c (1.05%). Further clinical studies that are more robust and better controlled are warranted to further explore these findings.
Statistical Analyses of Raw Material Data for MTM45-1/CF7442A-36% RW: CMH Cure Cycle
NASA Technical Reports Server (NTRS)
Coroneos, Rula; Pai, Shantaram, S.; Murthy, Pappu
2013-01-01
This report describes statistical characterization of physical properties of the composite material system MTM45-1/CF7442A, which has been tested and is currently being considered for use on spacecraft structures. This composite system is made of 6K plain weave graphite fibers in a highly toughened resin system. This report summarizes the distribution types and statistical details of the tests and the conditions for the experimental data generated. These distributions will be used in multivariate regression analyses to help determine material and design allowables for similar material systems and to establish a procedure for other material systems. Additionally, these distributions will be used in future probabilistic analyses of spacecraft structures. The specific properties that are characterized are the ultimate strength, modulus, and Poisson??s ratio by using a commercially available statistical package. Results are displayed using graphical and semigraphical methods and are included in the accompanying appendixes.
Estimating mortality using data from civil registration: a cross-sectional study in India
Rao, Chalapati; Lakshmi, PVM; Prinja, Shankar; Kumar, Rajesh
2016-01-01
Abstract Objective To analyse the design and operational status of India’s civil registration and vital statistics system and facilitate the system’s development into an accurate and reliable source of mortality data. Methods We assessed the national civil registration and vital statistics system’s legal framework, administrative structure and design through document review. We did a cross-sectional study for the year 2013 at national level and in Punjab state to assess the quality of the system’s mortality data through analyses of life tables and investigation of the completeness of death registration and the proportion of deaths assigned ill-defined causes. We interviewed registrars, medical officers and coders in Punjab state to assess their knowledge and practice. Findings Although we found the legal framework and system design to be appropriate, data collection was based on complex intersectoral collaborations at state and local level and the collected data were found to be of poor quality. The registration data were inadequate for a robust estimate of mortality at national level. A medically certified cause of death was only recorded for 965 992 (16.8%) of the 5 735 082 deaths registered. Conclusion The data recorded by India’s civil registration and vital statistics system in 2011 were incomplete. If improved, the system could be used to reliably estimate mortality. We recommend improving political support and intersectoral coordination, capacity building, computerization and state-level initiatives to ensure that every death is registered and that reliable causes of death are recorded – at least within an adequate sample of registration units within each state. PMID:26769992
The cost of an emergency department visit and its relationship to emergency department volume.
Bamezai, Anil; Melnick, Glenn; Nawathe, Amar
2005-05-01
This article addresses 2 questions: (1) to what extent do emergency departments (EDs) exhibit economies of scale; and (2) to what extent do publicly available accounting data understate the marginal cost of an outpatient ED visit? Understanding the appropriate role for EDs in the overall health care system is crucially dependent on answers to these questions. The literature on these issues is sparse and somewhat dated and fails to differentiate between trauma and nontrauma hospitals. We believe a careful review of these questions is necessary because several changes (greater managed care penetration, increased price competition, cost of compliance with Emergency Medical Treatment and Active Labor Act regulations, and so on) may have significantly altered ED economics in recent years. We use a 2-pronged approach, 1 based on descriptive analyses of publicly available accounting data and 1 based on statistical cost models estimated from a 9-year panel of hospital data, to address the above-mentioned questions. Neither the descriptive analyses nor the statistical models support the existence of significant scale economies. Furthermore, the marginal cost of outpatient ED visits, even without the emergency physician component, appear quite high--in 1998 dollars, US295 dollars and US412 dollars for nontrauma and trauma EDs, respectively. These statistical estimates exceed the accounting estimates of per-visit costs by a factor of roughly 2. Our findings suggest that the marginal cost of an outpatient ED visit is higher than is generally believed. Hospitals thus need to carefully review how EDs fit within their overall operations and cost structure and may need to pay special attention to policies and procedures that guide the delivery of nonurgent care through the ED.
NASA Astrophysics Data System (ADS)
Greenberg, Ariela Caren
Differential item functioning (DIF) and differential distractor functioning (DDF) are methods used to screen for item bias (Camilli & Shepard, 1994; Penfield, 2008). Using an applied empirical example, this mixed-methods study examined the congruency and relationship of DIF and DDF methods in screening multiple-choice items. Data for Study I were drawn from item responses of 271 female and 236 male low-income children on a preschool science assessment. Item analyses employed a common statistical approach of the Mantel-Haenszel log-odds ratio (MH-LOR) to detect DIF in dichotomously scored items (Holland & Thayer, 1988), and extended the approach to identify DDF (Penfield, 2008). Findings demonstrated that the using MH-LOR to detect DIF and DDF supported the theoretical relationship that the magnitude and form of DIF and are dependent on the DDF effects, and demonstrated the advantages of studying DIF and DDF in multiple-choice items. A total of 4 items with DIF and DDF and 5 items with only DDF were detected. Study II incorporated an item content review, an important but often overlooked and under-published step of DIF and DDF studies (Camilli & Shepard). Interviews with 25 female and 22 male low-income preschool children and an expert review helped to interpret the DIF and DDF results and their comparison, and determined that a content review process of studied items can reveal reasons for potential item bias that are often congruent with the statistical results. Patterns emerged and are discussed in detail. The quantitative and qualitative analyses were conducted in an applied framework of examining the validity of the preschool science assessment scores for evaluating science programs serving low-income children, however, the techniques can be generalized for use with measures across various disciplines of research.
Post Hoc Analyses of ApoE Genotype-Defined Subgroups in Clinical Trials.
Kennedy, Richard E; Cutter, Gary R; Wang, Guoqiao; Schneider, Lon S
2016-01-01
Many post hoc analyses of clinical trials in Alzheimer's disease (AD) and mild cognitive impairment (MCI) are in small Phase 2 trials. Subject heterogeneity may lead to statistically significant post hoc results that cannot be replicated in larger follow-up studies. We investigated the extent of this problem using simulation studies mimicking current trial methods with post hoc analyses based on ApoE4 carrier status. We used a meta-database of 24 studies, including 3,574 subjects with mild AD and 1,171 subjects with MCI/prodromal AD, to simulate clinical trial scenarios. Post hoc analyses examined if rates of progression on the Alzheimer's Disease Assessment Scale-cognitive (ADAS-cog) differed between ApoE4 carriers and non-carriers. Across studies, ApoE4 carriers were younger and had lower baseline scores, greater rates of progression, and greater variability on the ADAS-cog. Up to 18% of post hoc analyses for 18-month trials in AD showed greater rates of progression for ApoE4 non-carriers that were statistically significant but unlikely to be confirmed in follow-up studies. The frequency of erroneous conclusions dropped below 3% with trials of 100 subjects per arm. In MCI, rates of statistically significant differences with greater progression in ApoE4 non-carriers remained below 3% unless sample sizes were below 25 subjects per arm. Statistically significant differences for ApoE4 in post hoc analyses often reflect heterogeneity among small samples rather than true differential effect among ApoE4 subtypes. Such analyses must be viewed cautiously. ApoE genotype should be incorporated into the design stage to minimize erroneous conclusions.
Rao, Goutham; Lopez-Jimenez, Francisco; Boyd, Jack; D'Amico, Frank; Durant, Nefertiti H; Hlatky, Mark A; Howard, George; Kirley, Katherine; Masi, Christopher; Powell-Wiley, Tiffany M; Solomonides, Anthony E; West, Colin P; Wessel, Jennifer
2017-09-05
Meta-analyses are becoming increasingly popular, especially in the fields of cardiovascular disease prevention and treatment. They are often considered to be a reliable source of evidence for making healthcare decisions. Unfortunately, problems among meta-analyses such as the misapplication and misinterpretation of statistical methods and tests are long-standing and widespread. The purposes of this statement are to review key steps in the development of a meta-analysis and to provide recommendations that will be useful for carrying out meta-analyses and for readers and journal editors, who must interpret the findings and gauge methodological quality. To make the statement practical and accessible, detailed descriptions of statistical methods have been omitted. Based on a survey of cardiovascular meta-analyses, published literature on methodology, expert consultation, and consensus among the writing group, key recommendations are provided. Recommendations reinforce several current practices, including protocol registration; comprehensive search strategies; methods for data extraction and abstraction; methods for identifying, measuring, and dealing with heterogeneity; and statistical methods for pooling results. Other practices should be discontinued, including the use of levels of evidence and evidence hierarchies to gauge the value and impact of different study designs (including meta-analyses) and the use of structured tools to assess the quality of studies to be included in a meta-analysis. We also recommend choosing a pooling model for conventional meta-analyses (fixed effect or random effects) on the basis of clinical and methodological similarities among studies to be included, rather than the results of a test for statistical heterogeneity. © 2017 American Heart Association, Inc.
Campbell, Kikuko; Bond, Gary R; Drake, Robert E; McHugo, Gregory J; Xie, Haiyi
2010-08-01
Research on vocational rehabilitation for clients with severe mental illness over the past 2 decades has yielded inconsistent findings regarding client factors statistically related to employment. The present study aimed to elucidate the relationship between baseline client characteristics and competitive employment outcomes-job acquisition and total weeks worked during an 18-month follow-up-in Individual Placement and Support (IPS). Data from 4 recent randomized controlled trials of IPS were aggregated for within-group regression analyses. In the IPS sample (N = 307), work history was the only significant predictor for job acquisition, but receiving Supplemental Security Income-with or without Social Security Disability Insurance-was associated with fewer total weeks worked (2.0%-2.8% of the variance). In the comparison sample (N = 374), clients with a diagnosis of mood disorder or with less severe thought disorder symptoms were more likely to obtain competitive employment. The findings confirm that clients with severe mental illness interested in competitive work best benefit from high-fidelity supported employment regardless of their work history and sociodemographic and clinical background, and highlight the needs for changes in federal policies for disability income support and insurance regulations.
ERIC Educational Resources Information Center
National Science Foundation, Arlington, VA.
This document presents statistical data of direct federal science and engineering support to higher education institutions in the United States. Data presented in the report are collected annually and exclude financial support of an indirect nature. There are six categories of support presented: (1) "Research and Development"; (2) "Research and…
Freudenstein, John V; Chase, Mark W
2015-03-01
The largest subfamily of orchids, Epidendroideae, represents one of the most significant diversifications among flowering plants in terms of pollination strategy, vegetative adaptation and number of species. Although many groups in the subfamily have been resolved, significant relationships in the tree remain unclear, limiting conclusions about diversification and creating uncertainty in the classification. This study brings together DNA sequences from nuclear, plastid and mitochrondrial genomes in order to clarify relationships, to test associations of key characters with diversification and to improve the classification. Sequences from seven loci were concatenated in a supermatrix analysis for 312 genera representing most of epidendroid diversity. Maximum-likelihood and parsimony analyses were performed on this matrix and on subsets of the data to generate trees and to investigate the effect of missing values. Statistical character-associated diversification analyses were performed. Likelihood and parsimony analyses yielded highly resolved trees that are in strong agreement and show significant support for many key clades. Many previously proposed relationships among tribes and subtribes are supported, and some new relationships are revealed. Analyses of subsets of the data suggest that the relatively high number of missing data for the full analysis is not problematic. Diversification analyses show that epiphytism is most strongly associated with diversification among epidendroids, followed by expansion into the New World and anther characters that are involved with pollinator specificity, namely early anther inflexion, cellular pollinium stalks and the superposed pollinium arrangement. All tested characters show significant association with speciation in Epidendroideae, suggesting that no single character accounts for the success of this group. Rather, it appears that a succession of key features appeared that have contributed to diversification, sometimes in parallel. © The Author 2015. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
Winer, E Samuel; Cervone, Daniel; Bryant, Jessica; McKinney, Cliff; Liu, Richard T; Nadorff, Michael R
2016-09-01
A popular way to attempt to discern causality in clinical psychology is through mediation analysis. However, mediation analysis is sometimes applied to research questions in clinical psychology when inferring causality is impossible. This practice may soon increase with new, readily available, and easy-to-use statistical advances. Thus, we here provide a heuristic to remind clinical psychological scientists of the assumptions of mediation analyses. We describe recent statistical advances and unpack assumptions of causality in mediation, underscoring the importance of time in understanding mediational hypotheses and analyses in clinical psychology. Example analyses demonstrate that statistical mediation can occur despite theoretical mediation being improbable. We propose a delineation of mediational effects derived from cross-sectional designs into the terms temporal and atemporal associations to emphasize time in conceptualizing process models in clinical psychology. The general implications for mediational hypotheses and the temporal frameworks from within which they may be drawn are discussed. © 2016 Wiley Periodicals, Inc.
This tool allows users to animate cancer trends over time by cancer site and cause of death, race, and sex. Provides access to incidence, mortality, and survival. Select the type of statistic, variables, format, and then extract the statistics in a delimited format for further analyses.
Reporting and methodological quality of meta-analyses in urological literature
Xu, Jing
2017-01-01
Purpose To assess the overall quality of published urological meta-analyses and identify predictive factors for high quality. Materials and Methods We systematically searched PubMed to identify meta-analyses published from January 1st, 2011 to December 31st, 2015 in 10 predetermined major paper-based urology journals. The characteristics of the included meta-analyses were collected, and their reporting and methodological qualities were assessed by the PRISMA checklist (27 items) and AMSTAR tool (11 items), respectively. Descriptive statistics were used for individual items as a measure of overall compliance, and PRISMA and AMSTAR scores were calculated as the sum of adequately reported domains. Logistic regression was used to identify predictive factors for high qualities. Results A total of 183 meta-analyses were included. The mean PRISMA and AMSTAR scores were 22.74 ± 2.04 and 7.57 ± 1.41, respectively. PRISMA item 5, protocol and registration, items 15 and 22, risk of bias across studies, items 16 and 23, additional analysis had less than 50% adherence. AMSTAR item 1, “a priori” design, item 5, list of studies and item 10, publication bias had less than 50% adherence. Logistic regression analyses showed that funding support and “a priori” design were associated with superior reporting quality, following PRISMA guideline and “a priori” design were associated with superior methodological quality. Conclusions Reporting and methodological qualities of recently published meta-analyses in major paper-based urology journals are generally good. Further improvement could potentially be achieved by strictly adhering to PRISMA guideline and having “a priori” protocol. PMID:28439452
[Parental practices and pedestrian risk behaviors in Chilean adolescents].
Herrera, Andrea C; Repetto, Paula B
2014-08-01
Traffic accidents are the second leading cause of death among adolescents and young adults in Chile. However, few studies have examined this behavior among this age group. Parental practices have a great influence on risk behaviors in adolescents, such as substance use, sexuality and violence, among others. Specifically, we propose that these practices will influence pedestrian risk behaviors among adolescents. To study the role of parental practices such as mother and father support, and behavioral control (monitoring and presence of rules) in pedestrian risk behaviors of teenagers. A sample of 470 adolescents attending schools in the Metropolitan Region of Santiago, Chile were studied. They answered a self-administered questionnaire in which they were asked about parental practices and pedestrian risk behaviors. Analyses were performed using descriptive and inferential statistics, using multiple regression. Paternal support and the presence of rules were protective factors for pedestrian risky behaviors. However, maternal support or monitoring did not influence these behaviors. Parental practices influence pedestrian behaviors of teenagers. The study provides further evidence for the importance of these practices in the development of behavioral self-regulation.
Braga, Ludmila Candida de; Carvalho, Lidia Raquel de; Binder, Maria Cecília Pereira
2010-06-01
Common mental disorders (CMD) present high prevalence among general populations and workers with important individual and social consequences. This cross-sectional and descriptive study explores the relationship between psychological job demands, job control degree and job support and prevalence of CMD among primary health care workers of Botucatu - SP. The data collection was carried out using an unidentified self-administered questionnaire, with emphasis on items relating to demand-control-support situation and occurrence of CMD (Self Reporting Questionnaire, SRQ-20). The data were stored using the software Excel / Office XP 2003, and the statistical analyses were performed in SAS system. It was evidenced that 42.6% of primary health care workers presented CMD. The observed association - high prevalence of CMD with high-strain job (Karasek model) and low prevalence of CMD with low-strain job - indicates that, in the studied city, primary health care work conditions are contributive factors to workers' illness. The survey reveals the need of interventions aiming at caring the workers and also gets better work conditions and increase social support at work.
Atmospheric Convective Organization: Self-Organized Criticality or Homeostasis?
NASA Astrophysics Data System (ADS)
Yano, Jun-Ichi
2015-04-01
Atmospheric convection has a tendency organized on a hierarchy of scales ranging from the mesoscale to the planetary scales, with the latter especially manifested by the Madden-Julian oscillation. The present talk examines two major possible mechanisms of self-organization identified in wider literature from a phenomenological thermodynamic point of view by analysing a planetary-scale cloud-resolving model simulation. The first mechanism is self-organized criticality. A saturation tendency of precipitation rate with the increasing column-integrated water, reminiscence of critical phenomena, indicates self-organized criticality. The second is a self-regulation mechanism that is known as homeostasis in biology. A thermodynamic argument suggests that such self-regulation maintains the column-integrated water below a threshold by increasing the precipitation rate. Previous analyses of both observational data as well as cloud-resolving model (CRM) experiments give mixed results. A satellite data analysis suggests self-organized criticality. Some observational data as well as CRM experiments support homeostasis. Other analyses point to a combination of these two interpretations. In this study, a CRM experiment over a planetary-scale domain with a constant sea-surface temperature is analyzed. This analysis shows that the relation between the column-integrated total water and precipitation suggests self-organized criticality, whereas the one between the column-integrated water vapor and precipitation suggests homeostasis. The concurrent presence of these two mechanisms are further elaborated by detailed statistical and budget analyses. These statistics are scale invariant, reflecting a spatial scaling of precipitation processes. These self-organization mechanisms are most likely be best theoretically understood by the energy cycle of the convective systems consisting of the kinetic energy and the cloud-work function. The author has already investigated the behavior of this cycle system under a zero-dimensional configuration. Preliminary simulations of this cycle system over a two-dimensional domain will be presented.
A Framework for the Optimization of Discrete-Event Simulation Models
NASA Technical Reports Server (NTRS)
Joshi, B. D.; Unal, R.; White, N. H.; Morris, W. D.
1996-01-01
With the growing use of computer modeling and simulation, in all aspects of engineering, the scope of traditional optimization has to be extended to include simulation models. Some unique aspects have to be addressed while optimizing via stochastic simulation models. The optimization procedure has to explicitly account for the randomness inherent in the stochastic measures predicted by the model. This paper outlines a general purpose framework for optimization of terminating discrete-event simulation models. The methodology combines a chance constraint approach for problem formulation, together with standard statistical estimation and analyses techniques. The applicability of the optimization framework is illustrated by minimizing the operation and support resources of a launch vehicle, through a simulation model.
Vocational students' learning preferences: the interpretability of ipsative data.
Smith, P J
2000-02-01
A number of researchers have argued that ipsative data are not suitable for statistical procedures designed for normative data. Others have argued that the interpretability of such analyses of ipsative data are little affected where the number of variables and the sample size are sufficiently large. The research reported here represents a factor analysis of the scores on the Canfield Learning Styles Inventory for 1,252 students in vocational education. The results of the factor analysis of these ipsative data were examined in a context of existing theory and research on vocational students and lend support to the argument that the factor analysis of ipsative data can provide sensibly interpretable results.
Large, Matthew; Nielssen, Olav; Lackersteen, Steven; Smith, Glen
2010-02-01
Previous studies have found that rates of homicide of children aged under one (infant homicide) are associated with rates of suicide, but not with rates of homicide. Linear regression was used to examine associations among infant homicide, homicide, and suicide in samples of regions in the United States and other countries. Infant homicide rates were significantly and independently associated in all analyses with both total homicide and total suicide rates. The epidemiological evidence supports the clinical observation that infant homicides are due to a range of causes, including maternal mental illness, but are also related to the level of serious violence within a community.
Dissecting the genetics of complex traits using summary association statistics.
Pasaniuc, Bogdan; Price, Alkes L
2017-02-01
During the past decade, genome-wide association studies (GWAS) have been used to successfully identify tens of thousands of genetic variants associated with complex traits and diseases. These studies have produced extensive repositories of genetic variation and trait measurements across large numbers of individuals, providing tremendous opportunities for further analyses. However, privacy concerns and other logistical considerations often limit access to individual-level genetic data, motivating the development of methods that analyse summary association statistics. Here, we review recent progress on statistical methods that leverage summary association data to gain insights into the genetic basis of complex traits and diseases.
Statistical innovations in diagnostic device evaluation.
Yu, Tinghui; Li, Qin; Gray, Gerry; Yue, Lilly Q
2016-01-01
Due to rapid technological development, innovations in diagnostic devices are proceeding at an extremely fast pace. Accordingly, the needs for adopting innovative statistical methods have emerged in the evaluation of diagnostic devices. Statisticians in the Center for Devices and Radiological Health at the Food and Drug Administration have provided leadership in implementing statistical innovations. The innovations discussed in this article include: the adoption of bootstrap and Jackknife methods, the implementation of appropriate multiple reader multiple case study design, the application of robustness analyses for missing data, and the development of study designs and data analyses for companion diagnostics.
Statscasts: Screencasts for Complementing Lectures in Statistics Classes
ERIC Educational Resources Information Center
Dunn, Peter K.; McDonald, Christine; Loch, Birgit
2015-01-01
Students who are studying introductory statistics units but are enrolled in non-statistics majors often struggle with the content, and do not stay engaged. Support structures are in place at many Australian universities to help these students. Most of these are face-to-face support centres that the students can visit during opening hours. To…
"Dear Fresher …"--How Online Questionnaires Can Improve Learning and Teaching Statistics
ERIC Educational Resources Information Center
Bebermeier, Sarah; Nussbeck, Fridtjof W.; Ontrup, Greta
2015-01-01
Lecturers teaching statistics are faced with several challenges supporting students' learning in appropriate ways. A variety of methods and tools exist to facilitate students' learning on statistics courses. The online questionnaires presented in this report are a new, slightly different computer-based tool: the central aim was to support students…
An analysis of the relationship of flight hours and naval rotary wing aviation mishaps
2017-03-01
evidence to support indicators used for sequestration, high flight hours, night flight, and overwater flight had statistically significant effects on...estimates found enough evidence to support indicators used for sequestration, high flight hours, night flight, and overwater flight had statistically ...38 C. DESCRIPTIVE STATISTICS ................................................................38 D
Spatially explicit spectral analysis of point clouds and geospatial data
Buscombe, Daniel D.
2015-01-01
The increasing use of spatially explicit analyses of high-resolution spatially distributed data (imagery and point clouds) for the purposes of characterising spatial heterogeneity in geophysical phenomena necessitates the development of custom analytical and computational tools. In recent years, such analyses have become the basis of, for example, automated texture characterisation and segmentation, roughness and grain size calculation, and feature detection and classification, from a variety of data types. In this work, much use has been made of statistical descriptors of localised spatial variations in amplitude variance (roughness), however the horizontal scale (wavelength) and spacing of roughness elements is rarely considered. This is despite the fact that the ratio of characteristic vertical to horizontal scales is not constant and can yield important information about physical scaling relationships. Spectral analysis is a hitherto under-utilised but powerful means to acquire statistical information about relevant amplitude and wavelength scales, simultaneously and with computational efficiency. Further, quantifying spatially distributed data in the frequency domain lends itself to the development of stochastic models for probing the underlying mechanisms which govern the spatial distribution of geological and geophysical phenomena. The software packagePySESA (Python program for Spatially Explicit Spectral Analysis) has been developed for generic analyses of spatially distributed data in both the spatial and frequency domains. Developed predominantly in Python, it accesses libraries written in Cython and C++ for efficiency. It is open source and modular, therefore readily incorporated into, and combined with, other data analysis tools and frameworks with particular utility for supporting research in the fields of geomorphology, geophysics, hydrography, photogrammetry and remote sensing. The analytical and computational structure of the toolbox is described, and its functionality illustrated with an example of a high-resolution bathymetric point cloud data collected with multibeam echosounder.
Rear-facing versus forward-facing child restraints: an updated assessment.
McMurry, Timothy L; Arbogast, Kristy B; Sherwood, Christopher P; Vaca, Federico; Bull, Marilyn; Crandall, Jeff R; Kent, Richard W
2018-02-01
The National Highway Traffic Safety Administration and the American Academy of Pediatrics recommend children be placed in rear-facing child restraint systems (RFCRS) until at least age 2. These recommendations are based on laboratory biomechanical tests and field data analyses. Due to concerns raised by an independent researcher, we re-evaluated the field evidence in favour of RFCRS using the National Automotive Sampling System Crashworthiness Data System (NASS-CDS) database. Children aged 0 or 1 year old (0-23 months) riding in either rear-facing or forward-facing child restraint systems (FFCRS) were selected from the NASS-CDS database, and injury rates were compared by seat orientation using survey-weighted χ 2 tests. In order to compare with previous work, we analysed NASS-CDS years 1988-2003, and then updated the analyses to include all available data using NASS-CDS years 1988-2015. Years 1988-2015 of NASS-CDS contained 1107 children aged 0 or 1 year old meeting inclusion criteria, with 47 of these children sustaining injuries with Injury Severity Score of at least 9. Both 0-year-old and 1-year-old children in RFCRS had lower rates of injury than children in FFCRS, but the available sample size was too small for reasonable statistical power or to allow meaningful regression controlling for covariates. Non-US field data and laboratory tests support the recommendation that children be kept in RFCRS for as long as possible, but the US NASS-CDS field data are too limited to serve as a strong statistical basis for these recommendations. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
Kessel, K A; Habermehl, D; Bohn, C; Jäger, A; Floca, R O; Zhang, L; Bougatf, N; Bendl, R; Debus, J; Combs, S E
2012-12-01
Especially in the field of radiation oncology, handling a large variety of voluminous datasets from various information systems in different documentation styles efficiently is crucial for patient care and research. To date, conducting retrospective clinical analyses is rather difficult and time consuming. With the example of patients with pancreatic cancer treated with radio-chemotherapy, we performed a therapy evaluation by using an analysis system connected with a documentation system. A total number of 783 patients have been documented into a professional, database-based documentation system. Information about radiation therapy, diagnostic images and dose distributions have been imported into the web-based system. For 36 patients with disease progression after neoadjuvant chemoradiation, we designed and established an analysis workflow. After an automatic registration of the radiation plans with the follow-up images, the recurrence volumes are segmented manually. Based on these volumes the DVH (dose volume histogram) statistic is calculated, followed by the determination of the dose applied to the region of recurrence. All results are saved in the database and included in statistical calculations. The main goal of using an automatic analysis tool is to reduce time and effort conducting clinical analyses, especially with large patient groups. We showed a first approach and use of some existing tools, however manual interaction is still necessary. Further steps need to be taken to enhance automation. Already, it has become apparent that the benefits of digital data management and analysis lie in the central storage of data and reusability of the results. Therefore, we intend to adapt the analysis system to other types of tumors in radiation oncology.
Diaz, Francisco J; Berg, Michel J; Krebill, Ron; Welty, Timothy; Gidal, Barry E; Alloway, Rita; Privitera, Michael
2013-12-01
Due to concern and debate in the epilepsy medical community and to the current interest of the US Food and Drug Administration (FDA) in revising approaches to the approval of generic drugs, the FDA is currently supporting ongoing bioequivalence studies of antiepileptic drugs, the EQUIGEN studies. During the design of these crossover studies, the researchers could not find commercial or non-commercial statistical software that quickly allowed computation of sample sizes for their designs, particularly software implementing the FDA requirement of using random-effects linear models for the analyses of bioequivalence studies. This article presents tables for sample-size evaluations of average bioequivalence studies based on the two crossover designs used in the EQUIGEN studies: the four-period, two-sequence, two-formulation design, and the six-period, three-sequence, three-formulation design. Sample-size computations assume that random-effects linear models are used in bioequivalence analyses with crossover designs. Random-effects linear models have been traditionally viewed by many pharmacologists and clinical researchers as just mathematical devices to analyze repeated-measures data. In contrast, a modern view of these models attributes an important mathematical role in theoretical formulations in personalized medicine to them, because these models not only have parameters that represent average patients, but also have parameters that represent individual patients. Moreover, the notation and language of random-effects linear models have evolved over the years. Thus, another goal of this article is to provide a presentation of the statistical modeling of data from bioequivalence studies that highlights the modern view of these models, with special emphasis on power analyses and sample-size computations.
Huvane, Jacqueline; Komarow, Lauren; Hill, Carol; Tran, Thuy Tien T.; Pereira, Carol; Rosenkranz, Susan L.; Finnemeyer, Matt; Earley, Michelle; Jiang, Hongyu (Jeanne); Wang, Rui; Lok, Judith
2017-01-01
Abstract The Statistical and Data Management Center (SDMC) provides the Antibacterial Resistance Leadership Group (ARLG) with statistical and data management expertise to advance the ARLG research agenda. The SDMC is active at all stages of a study, including design; data collection and monitoring; data analyses and archival; and publication of study results. The SDMC enhances the scientific integrity of ARLG studies through the development and implementation of innovative and practical statistical methodologies and by educating research colleagues regarding the application of clinical trial fundamentals. This article summarizes the challenges and roles, as well as the innovative contributions in the design, monitoring, and analyses of clinical trials and diagnostic studies, of the ARLG SDMC. PMID:28350899
2017-01-01
Background The home environment is where young children spend most of their time, and is critically important to supporting behaviors that promote health and prevent obesity. However, the home environment and lifestyle patterns remain understudied, and few interventions have investigated parent-led makeovers designed to create home environments that are supportive of optimal child health and healthy child weights. Objective The aim of the HomeStyles randomized controlled trial (RCT) is to determine whether the Web-based HomeStyles intervention enables and motivates parents to shape the weight-related aspects of their home environments and lifestyle behavioral practices (diet, exercise, and sleep) to be more supportive of their preschool children’s optimal health and weight. Methods A rigorous RCT utilizing an experimental group and an attention control group, receiving a bona fide contemporaneous treatment equal in nonspecific treatment effects and differing only in subject matter content, will test the effect of HomeStyles on a diverse sample of families with preschool children. This intervention is based on social cognitive theory and uses a social ecological framework, and will assess: intrapersonal characteristics (dietary intake, physical activity level, and sleep) of parents and children; family interpersonal or social characteristics related to diet, physical activity, media use, and parental values and self-efficacy for obesity-preventive practices; and home environment food availability, physical activity space and supports in and near the home, and media availability and controls in the home. Results Enrollment for this study has been completed and statistical data analyses are currently underway. Conclusions This paper describes the HomeStyles intervention with regards to: rationale, the intervention’s logic model, sample eligibility criteria and recruitment, experimental group and attention control intervention content, study design, instruments, data management, and planned analyses. PMID:28442452
Pastori, Matteo Mario; Sarti, Manuela; Pons, Marco; Barazzoni, Fabrizio
2014-10-01
To assess and quantify the impact of the literature in diagnostic decisions and treatment of patients admitted to an internal medicine service using the methodology of evidence-based medicine. From November 2012 to February 2013, patients who were hospitalised in the internal medicine service of Regional Hospital of Lugano (Switzerland) and generated questions on medical care were randomly assigned to two groups: an 'intervention group' (supported by the literature research) and a 'control group' (not supported by the literature research). The information obtained from the literature was submitted by email to all members of the medical team within 12 h after asking the question. Two hundred and one participants, from 866 patients hospitalised in the analysed period, divided into intervention (n=101) and control (n=100) groups, generated questions. In the intervention group, bibliographical research was possible for 98 participants. The medical team accepted the results and implemented the research for 90.8% of these participants (89/98). Statistical analyses were carried out on the intention-to-treat and on the per-protocol populations. Bibliographical research had a significant protective effect on transfer to an intensive care unit (relative risk (RR)=0.30; 95% CI 0.10 to 0.90; χ²=5.3, p=0.02) and hospital readmissions were also influenced by bibliographical research (RR=0.42; 95% CI 0.17 to 1.0; χ²=3.36, p=0.05) in the intention-to-treat population. Our results point out the importance of bibliographical support on the quality of medical care. In particular, they show its possible impact on clinical outcome. EOC Registry (registration number: 14-055).
Analogy as a strategy for supporting complex problem solving under uncertainty.
Chan, Joel; Paletz, Susannah B F; Schunn, Christian D
2012-11-01
Complex problem solving in naturalistic environments is fraught with uncertainty, which has significant impacts on problem-solving behavior. Thus, theories of human problem solving should include accounts of the cognitive strategies people bring to bear to deal with uncertainty during problem solving. In this article, we present evidence that analogy is one such strategy. Using statistical analyses of the temporal dynamics between analogy and expressed uncertainty in the naturalistic problem-solving conversations among scientists on the Mars Rover Mission, we show that spikes in expressed uncertainty reliably predict analogy use (Study 1) and that expressed uncertainty reduces to baseline levels following analogy use (Study 2). In addition, in Study 3, we show with qualitative analyses that this relationship between uncertainty and analogy is not due to miscommunication-related uncertainty but, rather, is primarily concentrated on substantive problem-solving issues. Finally, we discuss a hypothesis about how analogy might serve as an uncertainty reduction strategy in naturalistic complex problem solving.
imDEV: a graphical user interface to R multivariate analysis tools in Microsoft Excel
Grapov, Dmitry; Newman, John W.
2012-01-01
Summary: Interactive modules for Data Exploration and Visualization (imDEV) is a Microsoft Excel spreadsheet embedded application providing an integrated environment for the analysis of omics data through a user-friendly interface. Individual modules enables interactive and dynamic analyses of large data by interfacing R's multivariate statistics and highly customizable visualizations with the spreadsheet environment, aiding robust inferences and generating information-rich data visualizations. This tool provides access to multiple comparisons with false discovery correction, hierarchical clustering, principal and independent component analyses, partial least squares regression and discriminant analysis, through an intuitive interface for creating high-quality two- and a three-dimensional visualizations including scatter plot matrices, distribution plots, dendrograms, heat maps, biplots, trellis biplots and correlation networks. Availability and implementation: Freely available for download at http://sourceforge.net/projects/imdev/. Implemented in R and VBA and supported by Microsoft Excel (2003, 2007 and 2010). Contact: John.Newman@ars.usda.gov Supplementary Information: Installation instructions, tutorials and users manual are available at http://sourceforge.net/projects/imdev/. PMID:22815358
Exploring spatial evolution of economic clusters: A case study of Beijing
NASA Astrophysics Data System (ADS)
Yang, Zhenshan; Sliuzas, Richard; Cai, Jianming; Ottens, Henk F. L.
2012-10-01
An identification of economic clusters and analysing their changing spatial patterns is important for understanding urban economic space dynamics. Previous studies, however, suffer from limitations as a consequence of using fixed geographically areas and not combining functional and spatial dynamics. The paper presents an approach, based on local spatial statistics and the case of Beijing to understand the spatial clustering of industries that are functionally interconnected by common or complementary patterns of demand or supply relations. Using register data of business establishments, it identifies economic clusters and analyses their pattern based on postcodes at different time slices during the period 1983-2002. The study shows how the advanced services occupy the urban centre and key sub centres. The Information and Communication Technology (ICT) cluster is mainly concentrated in the north part of the city and circles the urban centre, and the main manufacturing clusters are evolved in the key sub centers. This type of outcomes improves understanding of urban-economic dynamics, which can support spatial and economic planning.
The MR-Base platform supports systematic causal inference across the human phenome
Wade, Kaitlin H; Haberland, Valeriia; Baird, Denis; Laurin, Charles; Burgess, Stephen; Bowden, Jack; Langdon, Ryan; Tan, Vanessa Y; Yarmolinsky, James; Shihab, Hashem A; Timpson, Nicholas J; Evans, David M; Relton, Caroline; Martin, Richard M; Davey Smith, George
2018-01-01
Results from genome-wide association studies (GWAS) can be used to infer causal relationships between phenotypes, using a strategy known as 2-sample Mendelian randomization (2SMR) and bypassing the need for individual-level data. However, 2SMR methods are evolving rapidly and GWAS results are often insufficiently curated, undermining efficient implementation of the approach. We therefore developed MR-Base (http://www.mrbase.org): a platform that integrates a curated database of complete GWAS results (no restrictions according to statistical significance) with an application programming interface, web app and R packages that automate 2SMR. The software includes several sensitivity analyses for assessing the impact of horizontal pleiotropy and other violations of assumptions. The database currently comprises 11 billion single nucleotide polymorphism-trait associations from 1673 GWAS and is updated on a regular basis. Integrating data with software ensures more rigorous application of hypothesis-driven analyses and allows millions of potential causal relationships to be efficiently evaluated in phenome-wide association studies. PMID:29846171
NASA Technical Reports Server (NTRS)
Kolm, K. E.
1975-01-01
The author has identified the following significant results. Seleniferous Shingle series soils and sandstone outcrops of section 27, T 48 N, R 71 W, Wyoming are mapped on aerial photography by their association with Astragalus bisulcatus. Chemical leachate analyses and atomic absorption methods reveal all studied Samsil and Shingle soils to contain acid, base, and water soluble selenium compounds, and that water extractions showed varied concentration behavior due to soil pH. Acid-soluble selenium is found to be associated with smectite. Statistical analyses confirm that A. bisulcatus presence has a weak influence on soil-lens organic selenium concentration, and determine the importance of other geobotanical factors for convertor presence. Environmental procedures of high selenium lens burial, convertor plant eradication, and revegetated site monitoring are recommended. Usage of density analysis and photographic enlargement are used to successfully produce both a control area and a Campbell County, Wyoming regional map of A. bisulcatus supportive soils and outcrops using Skylab photography.
Øktedalen, Tuva; Hoffart, Asle; Langkaas, Tomas Formo
2015-01-01
The specific aims of this study are to examine trauma-related shame and guilt as time-varying predictors of symptoms of posttraumatic stress disorder (PTSD). Sixty-five patients were included in the statistical analyses and the multilevel modeling analyses supported three major findings. (i) Patients with a higher level of shame and guilt at the start of treatment displayed a higher level of PTSD symptoms over the course of treatment compared to other patients. (ii) Time-specific change in shame and guilt predicted the level of PTSD symptoms 3 days later from session to session during treatment. (iii) No significant differences were evident between prolonged exposure (PE) and modified PE to include imagery rescripting in the within-person process of change in PTSD symptoms from session to session during therapy. This trial reports the first evidence that within-person change in shame and guilt predicts change in PTSD symptoms from session to session during treatment.
ISSUES IN THE STATISTICAL ANALYSIS OF SMALL-AREA HEALTH DATA. (R825173)
The availability of geographically indexed health and population data, with advances in computing, geographical information systems and statistical methodology, have opened the way for serious exploration of small area health statistics based on routine data. Such analyses may be...
3D-Digital soil property mapping by geoadditive models
NASA Astrophysics Data System (ADS)
Papritz, Andreas
2016-04-01
In many digital soil mapping (DSM) applications, soil properties must be predicted not only for a single but for multiple soil depth intervals. In the GlobalSoilMap project, as an example, predictions are computed for the 0-5 cm, 5-15 cm, 15-30 cm, 30-60 cm, 60-100 cm, 100-200 cm depth intervals (Arrouays et al., 2014). Legacy soil data are often used for DSM. It is common for such datasets that soil properties were measured for soil horizons or for layers at varying soil depth and with non-constant thickness (support). This poses problems for DSM: One strategy is to harmonize the soil data to common depth prior to the analyses (e.g. Bishop et al., 1999) and conduct the statistical analyses for each depth interval independently. The disadvantage of this approach is that the predictions for different depths are computed independently from each other so that the predicted depth profiles may be unrealistic. Furthermore, the error induced by the harmonization to common depth is ignored in this approach (Orton et al. 2016). A better strategy is therefore to process all soil data jointly without prior harmonization by a 3D-analysis that takes soil depth and geographical position explicitly into account. Usually, the non-constant support of the data is then ignored, but Orton et al. (2016) presented recently a geostatistical approach that accounts for non-constant support of soil data and relies on restricted maximum likelihood estimation (REML) of a linear geostatistical model with a separable, heteroscedastic, zonal anisotropic auto-covariance function and area-to-point kriging (Kyriakidis, 2004.) Although this model is theoretically coherent and elegant, estimating its many parameters by REML and selecting covariates for the spatial mean function is a formidable task. A simpler approach might be to use geoadditive models (Kammann and Wand, 2003; Wand, 2003) for 3D-analyses of soil data. geoAM extend the scope of the linear model with spatially correlated errors to account for nonlinear effects of covariates by fitting componentwise smooth, nonlinear functions to the covariates (additive terms). REML estimation of model parameters and computing best linear unbiased predictions (BLUP) builds in the geoAM framework on the fact that both geostatistical and additive models can be parametrized as linear mixed models Wand, 2003. For 3D-DSM analysis of soil data, it is natural to model depth profiles of soil properties by additive terms of soil depth. Including interactions between these additive terms and covariates of the spatial mean function allows to model spatially varying depth profiles. Furthermore, with suitable choice of the basis functions of the additive term (e.g. polynomial regression splines), non-constant support of the soil data can be taken into account. Finally, boosting (Bühlmann and Hothorn, 2007) can be used for selecting covariates for the spatial mean function. The presentation will detail the geoAM approach and present an example of geoAM for 3D-analysis of legacy soil data. Arrouays, D., McBratney, A. B., Minasny, B., Hempel, J. W., Heuvelink, G. B. M., MacMillan, R. A., Hartemink, A. E., Lagacherie, P., and McKenzie, N. J. (2014). The GlobalSoilMap project specifications. In GlobalSoilMap Basis of the global spatial soil information system, pages 9-12. CRC Press. Bishop, T., McBratney, A., and Laslett, G. (1999). Modelling soil attribute depth functions with equal-area quadratic smoothing splines. Geoderma, 91(1-2), 27-45. Bühlmann, P. and Hothorn, T. (2007). Boosting algorithms: Regularization, prediction and model fitting. Statistical Science, 22(4), 477-505. Kammann, E. E. and Wand, M. P. (2003). Geoadditive models. Journal of the Royal Statistical Society. Series C: Applied Statistics, 52(1), 1-18. Kyriakidis, P. (2004). A geostatistical framework for area-to-point spatial interpolation. Geographical Analysis, 36(3), 259-289. Orton, T., Pringle, M., and Bishop, T. (2016). A one-step approach for modelling and mapping soil properties based on profile data sampled over varying depth intervals. Geoderma, 262, 174-186. Wand, M. P. (2003). Smoothing and mixed models. Computational Statistics, 18(2), 223-249.
Johnsen, Tone Langjordet; Eriksen, Hege Randi; Indahl, Aage; Tveito, Torill Helene
2017-01-01
Aims: Social support is associated with well-being and positive health outcomes. However, positive outcomes of social support might be more dependent on the way support is provided than the amount of support received. A distinction can be made between directive social support, where the provider resumes responsibility, and nondirective social support, where the receiver has the control. This study examined the relationship between directive and nondirective social support, and subjective health complaints, job satisfaction and perception of job demands and job control. Methods: A survey was conducted among 957 Norwegian employees, working in 114 private kindergartens (mean age 40.7 years, SD = 10.5, 92.8% female), as part of a randomized controlled trial. This study used only baseline data. A factor analysis of the Norwegian version of the Social Support Inventory was conducted, identifying two factors: nondirective and directive social support. Hierarchical regression analyses were then performed. Results: Nondirective social support was related to fewer musculoskeletal and pseudoneurological complaints, higher job satisfaction, and the perception of lower job demands and higher job control. Directive social support had the opposite relationship, but was not statistically significant for pseudoneurological complaints. Conclusions: It appears that for social support to be positively related with job characteristics and subjective health complaints, it has to be nondirective. Directive social support was not only without any association, but had a significant negative relationship with several of the variables. Nondirective social support may be an important factor to consider when aiming to improve the psychosocial work environment. Trial registration: Clinicaltrials.gov: NCT02396797. Registered 23 March 2015. PMID:28820017
Johnsen, Tone Langjordet; Eriksen, Hege Randi; Indahl, Aage; Tveito, Torill Helene
2018-05-01
Social support is associated with well-being and positive health outcomes. However, positive outcomes of social support might be more dependent on the way support is provided than the amount of support received. A distinction can be made between directive social support, where the provider resumes responsibility, and nondirective social support, where the receiver has the control. This study examined the relationship between directive and nondirective social support, and subjective health complaints, job satisfaction and perception of job demands and job control. A survey was conducted among 957 Norwegian employees, working in 114 private kindergartens (mean age 40.7 years, SD = 10.5, 92.8% female), as part of a randomized controlled trial. This study used only baseline data. A factor analysis of the Norwegian version of the Social Support Inventory was conducted, identifying two factors: nondirective and directive social support. Hierarchical regression analyses were then performed. Nondirective social support was related to fewer musculoskeletal and pseudoneurological complaints, higher job satisfaction, and the perception of lower job demands and higher job control. Directive social support had the opposite relationship, but was not statistically significant for pseudoneurological complaints. It appears that for social support to be positively related with job characteristics and subjective health complaints, it has to be nondirective. Directive social support was not only without any association, but had a significant negative relationship with several of the variables. Nondirective social support may be an important factor to consider when aiming to improve the psychosocial work environment. Clinicaltrials.gov: NCT02396797. Registered 23 March 2015.
Nonindependence and sensitivity analyses in ecological and evolutionary meta-analyses.
Noble, Daniel W A; Lagisz, Malgorzata; O'dea, Rose E; Nakagawa, Shinichi
2017-05-01
Meta-analysis is an important tool for synthesizing research on a variety of topics in ecology and evolution, including molecular ecology, but can be susceptible to nonindependence. Nonindependence can affect two major interrelated components of a meta-analysis: (i) the calculation of effect size statistics and (ii) the estimation of overall meta-analytic estimates and their uncertainty. While some solutions to nonindependence exist at the statistical analysis stages, there is little advice on what to do when complex analyses are not possible, or when studies with nonindependent experimental designs exist in the data. Here we argue that exploring the effects of procedural decisions in a meta-analysis (e.g. inclusion of different quality data, choice of effect size) and statistical assumptions (e.g. assuming no phylogenetic covariance) using sensitivity analyses are extremely important in assessing the impact of nonindependence. Sensitivity analyses can provide greater confidence in results and highlight important limitations of empirical work (e.g. impact of study design on overall effects). Despite their importance, sensitivity analyses are seldom applied to problems of nonindependence. To encourage better practice for dealing with nonindependence in meta-analytic studies, we present accessible examples demonstrating the impact that ignoring nonindependence can have on meta-analytic estimates. We also provide pragmatic solutions for dealing with nonindependent study designs, and for analysing dependent effect sizes. Additionally, we offer reporting guidelines that will facilitate disclosure of the sources of nonindependence in meta-analyses, leading to greater transparency and more robust conclusions. © 2017 John Wiley & Sons Ltd.
Boehm, Jackie; Cordier, Reinie; Thomas, Yvonne; Tanner, Bronwyn; Salata, Karen
2017-02-01
Student retention at regional universities is important in addressing regional and remote workforce shortages. Students attending regional universities are more likely to work in regional areas. First year experience at university plays a key role in student retention. This study aimed to explore factors influencing the first year experience of occupational therapy students at a regional Australian university. Surveys were administered to 58 second year occupational therapy students in the first week of second year. Data were analysed using descriptive statistics, inferential statistics (Pearson χ 2 ; Spearman rho) and summarising descriptive responses. An Australian regional university. Second year undergraduate occupational therapy students. Factors influencing students' decisions to study and continue studying occupational therapy; factors enhancing first year experience of university. Fifty-four students completed the survey (93.1%). A quarter (25.9%) of students considered leaving the course during the first year. The primary influence for continuing was the teaching and learning experience. Most valued supports were orientation week (36.7%) and the first year coordinator (36.7%). The importance of the first year experience in retaining occupational therapy students is highlighted. Engagement with other students and staff and academic support are important factors in facilitating student retention. It is important to understand the unique factors influencing students' decisions, particularly those from regional and remote areas, to enter and continue in tertiary education to assist in implementing supports and strategies to improve student retention. © 2015 National Rural Health Alliance Inc.
Psychometric assessment of the IBS-D Daily Symptom Diary and Symptom Event Log.
Rosa, Kathleen; Delgado-Herrera, Leticia; Zeiher, Bernie; Banderas, Benjamin; Arbuckle, Rob; Spears, Glen; Hudgens, Stacie
2016-12-01
Diarrhea-predominant irritable bowel syndrome (IBS-D) can considerably impact patients' lives. Patient-reported symptoms are crucial in understanding the diagnosis and progression of IBS-D. This study psychometrically evaluates the newly developed IBS-D Daily Symptom Diary and Symptom Event Log (hereafter, "Event Log") according to US regulatory recommendations. A US-based observational field study was conducted to understand cross-sectional psychometric properties of the IBS-D Daily Symptom Diary and Event Log. Analyses included item descriptive statistics, item-to-item correlations, reliability, and construct validity. The IBS-D Daily Symptom Diary and Event Log had no items with excessive missing data. With the exception of two items ("frequency of gas" and "accidents"), moderate to high inter-item correlations were observed among all items of the IBS-D Daily Symptom Diary and Event Log (day 1 range 0.67-0.90). Item scores demonstrated reliability, with the exception of the "frequency of gas" and "accidents" items of the Diary and "incomplete evacuation" item of the Event Log. The pattern of correlations of the IBS-D Daily Symptom Diary and Event Log item scores with generic and disease-specific measures was as expected, moderate for similar constructs and low for dissimilar constructs, supporting construct validity. Known-groups methods showed statistically significant differences and monotonic trends in each of the IBS-D Daily Symptom Diary item scores among groups defined by patients' IBS-D severity ratings ("none"/"mild," "moderate," or "severe"/"very severe"), supporting construct validity. Initial psychometric results support the reliability and validity of the items of the IBS-D Daily Symptom Diary and Event Log.
Does educational status impact adult mortality in Denmark? A twin approach.
Madsen, Mia; Andersen, Anne-Marie Nybo; Christensen, Kaare; Andersen, Per Kragh; Osler, Merete
2010-07-15
To disentangle an independent effect of educational status on mortality risk from direct and indirect selection mechanisms, the authors used a discordant twin pair design, which allowed them to isolate the effect of education by means of adjustment for genetic and environmental confounding per design. The study is based on data from the Danish Twin Registry and Statistics Denmark. Using Cox regression, they estimated hazard ratios for mortality according to the highest attained education among 5,260 monozygotic and 11,088 dizygotic same-sex twin pairs born during 1921-1950 and followed during 1980-2008. Both standard cohort and intrapair analyses were conducted separately for zygosity, gender, and birth cohort. Educational differences in mortality were demonstrated in the standard cohort analyses but attenuated in the intrapair analyses in all subgroups but men born during 1921-1935, and no effect modification by zygosity was observed. Hence, the results are most compatible with an effect of early family environment in explaining the educational inequality in mortality. However, large educational differences were still reflected in mortality risk differences within twin pairs, thus supporting some degree of independent effect of education. In addition, the effect of education may be more pronounced in older cohorts of Danish men.
A duplicate gene rooting of seed plants and the phylogenetic position of flowering plants
Mathews, Sarah; Clements, Mark D.; Beilstein, Mark A.
2010-01-01
Flowering plants represent the most significant branch in the tree of land plants, with respect to the number of extant species, their impact on the shaping of modern ecosystems and their economic importance. However, unlike so many persistent phylogenetic problems that have yielded to insights from DNA sequence data, the mystery surrounding the origin of angiosperms has deepened with the advent and advance of molecular systematics. Strong statistical support for competing hypotheses and recent novel trees from molecular data suggest that the accuracy of current molecular trees requires further testing. Analyses of phytochrome amino acids using a duplicate gene-rooting approach yield trees that unite cycads and angiosperms in a clade that is sister to a clade in which Gingko and Cupressophyta are successive sister taxa to gnetophytes plus Pinaceae. Application of a cycads + angiosperms backbone constraint in analyses of a morphological dataset yields better resolved trees than do analyses in which extant gymnosperms are forced to be monophyletic. The results have implications both for our assessment of uncertainty in trees from sequence data and for our use of molecular constraints as a way to integrate insights from morphological and molecular evidence. PMID:20047866
Evaluation of atpB nucleotide sequences for phylogenetic studies of ferns and other pteridophytes.
Wolf, P
1997-10-01
Inferring basal relationships among vascular plants poses a major challenge to plant systematists. The divergence events that describe these relationships occurred long ago and considerable homoplasy has since accrued for both molecular and morphological characters. A potential solution is to examine phylogenetic analyses from multiple data sets. Here I present a new source of phylogenetic data for ferns and other pteridophytes. I sequenced the chloroplast gene atpB from 23 pteridophyte taxa and used maximum parsimony to infer relationships. A 588-bp region of the gene appeared to contain a statistically significant amount of phylogenetic signal and the resulting trees were largely congruent with similar analyses of nucleotide sequences from rbcL. However, a combined analysis of atpB plus rbcL produced a better resolved tree than did either data set alone. In the shortest trees, leptosporangiate ferns formed a monophyletic group. Also, I detected a well-supported clade of Psilotaceae (Psilotum and Tmesipteris) plus Ophioglossaceae (Ophioglossum and Botrychium). The demonstrated utility of atpB suggests that sequences from this gene should play a role in phylogenetic analyses that incorporate data from chloroplast genes, nuclear genes, morphology, and fossil data.
ERIC Educational Resources Information Center
Conant, Darcy Lynn
2013-01-01
Stochastic understanding of probability distribution undergirds development of conceptual connections between probability and statistics and supports development of a principled understanding of statistical inference. This study investigated the impact of an instructional course intervention designed to support development of stochastic…
Neville, Kathleen; DiBona, Courtney; Mahler, Maureen
2016-01-01
Hourly rounds have re-emerged as standard practice among nurses in acute care settings, and there is the need to identify nurses' perceptions regarding this practice. Further use of the Nurses' Perception of Patient Rounding Scale (NPPRS) is needed to further validate this new instrument. In addition, there exists a dearth of literature that examines the impact of hours worked and shift on nurses' perceptions of patient rounding. The purpose of this descriptive study was to explore nurses' perception of the required practice of patient rounding, to examine the influence of nurses' shift on nurses' perception of rounding practice, and to provide additional psychometric support for the NPPRS. The NPPRS, a 42-item scale in 5-point Likert format, and a demographic information sheet were used in the study. The NPPRS yields three subscales: communication, patient benefits, and nurse benefits. Using a convenience sample of anonymous nurse participants, 76 nurses from five medical-surgical units at a medical center in the northeast corridor of the United States participated in the study. Further psychometric support for the NPPRS was demonstrated. Excellent reliability coefficients via Cronbach's alpha for the total scale (0.91) and each of the subscales were obtained. A statistically significant difference was noted among nurses working 8 hours versus 12 hours or combined 8- and 12-hour workloads. Perceptions of nurse benefits were statistically significantly higher for nurses working 8 hours. In addition, results indicated that nurses perceived rounding to be more beneficial to their own practice than to patients. Analyses revealed that leadership support was instrumental in successful rounding practice. Further support for the NPPRS was obtained through this study. Strong nursing leadership, supportive of rounding, is essential for successful rounding. Further research should examine the efficacy of nurse rounding-developed protocols specific to the shift and unit of nursing practice.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Metoyer, Candace N.; Walsh, Stephen J.; Tardiff, Mark F.
2008-10-30
The detection and identification of weak gaseous plumes using thermal imaging data is complicated by many factors. These include variability due to atmosphere, ground and plume temperature, and background clutter. This paper presents an analysis of one formulation of the physics-based model that describes the at-sensor observed radiance. The motivating question for the analyses performed in this paper is as follows. Given a set of backgrounds, is there a way to predict the background over which the probability of detecting a given chemical will be the highest? Two statistics were developed to address this question. These statistics incorporate data frommore » the long-wave infrared band to predict the background over which chemical detectability will be the highest. These statistics can be computed prior to data collection. As a preliminary exploration into the predictive ability of these statistics, analyses were performed on synthetic hyperspectral images. Each image contained one chemical (either carbon tetrachloride or ammonia) spread across six distinct background types. The statistics were used to generate predictions for the background ranks. Then, the predicted ranks were compared to the empirical ranks obtained from the analyses of the synthetic images. For the simplified images under consideration, the predicted and empirical ranks showed a promising amount of agreement. One statistic accurately predicted the best and worst background for detection in all of the images. Future work may include explorations of more complicated plume ingredients, background types, and noise structures.« less
Tuuli, Methodius G; Odibo, Anthony O
2011-08-01
The objective of this article is to discuss the rationale for common statistical tests used for the analysis and interpretation of prenatal diagnostic imaging studies. Examples from the literature are used to illustrate descriptive and inferential statistics. The uses and limitations of linear and logistic regression analyses are discussed in detail.
Using a Five-Step Procedure for Inferential Statistical Analyses
ERIC Educational Resources Information Center
Kamin, Lawrence F.
2010-01-01
Many statistics texts pose inferential statistical problems in a disjointed way. By using a simple five-step procedure as a template for statistical inference problems, the student can solve problems in an organized fashion. The problem and its solution will thus be a stand-by-itself organic whole and a single unit of thought and effort. The…
Harris, Michael; Radtke, Arthur S.
1976-01-01
Linear regression and discriminant analyses techniques were applied to gold, mercury, arsenic, antimony, barium, copper, molybdenum, lead, zinc, boron, tellurium, selenium, and tungsten analyses from drill holes into unoxidized gold ore at the Carlin gold mine near Carlin, Nev. The statistical treatments employed were used to judge proposed hypotheses on the origin and geochemical paragenesis of this disseminated gold deposit.
ERIC Educational Resources Information Center
Neumann, David L.; Hood, Michelle
2009-01-01
A wiki was used as part of a blended learning approach to promote collaborative learning among students in a first year university statistics class. One group of students analysed a data set and communicated the results by jointly writing a practice report using a wiki. A second group analysed the same data but communicated the results in a…
Verbruggen, Heroen; Maggs, Christine A; Saunders, Gary W; Le Gall, Line; Yoon, Hwan Su; De Clerck, Olivier
2010-01-20
The assembly of the tree of life has seen significant progress in recent years but algae and protists have been largely overlooked in this effort. Many groups of algae and protists have ancient roots and it is unclear how much data will be required to resolve their phylogenetic relationships for incorporation in the tree of life. The red algae, a group of primary photosynthetic eukaryotes of more than a billion years old, provide the earliest fossil evidence for eukaryotic multicellularity and sexual reproduction. Despite this evolutionary significance, their phylogenetic relationships are understudied. This study aims to infer a comprehensive red algal tree of life at the family level from a supermatrix containing data mined from GenBank. We aim to locate remaining regions of low support in the topology, evaluate their causes and estimate the amount of data required to resolve them. Phylogenetic analysis of a supermatrix of 14 loci and 98 red algal families yielded the most complete red algal tree of life to date. Visualization of statistical support showed the presence of five poorly supported regions. Causes for low support were identified with statistics about the age of the region, data availability and node density, showing that poor support has different origins in different parts of the tree. Parametric simulation experiments yielded optimistic estimates of how much data will be needed to resolve the poorly supported regions (ca. 103 to ca. 104 nucleotides for the different regions). Nonparametric simulations gave a markedly more pessimistic image, some regions requiring more than 2.8 105 nucleotides or not achieving the desired level of support at all. The discrepancies between parametric and nonparametric simulations are discussed in light of our dataset and known attributes of both approaches. Our study takes the red algae one step closer to meaningful inclusion in the tree of life. In addition to the recovery of stable relationships, the recognition of five regions in need of further study is a significant outcome of this work. Based on our analyses of current availability and future requirements of data, we make clear recommendations for forthcoming research.
Extreme between-study homogeneity in meta-analyses could offer useful insights.
Ioannidis, John P A; Trikalinos, Thomas A; Zintzaras, Elias
2006-10-01
Meta-analyses are routinely evaluated for the presence of large between-study heterogeneity. We examined whether it is also important to probe whether there is extreme between-study homogeneity. We used heterogeneity tests with left-sided statistical significance for inference and developed a Monte Carlo simulation test for testing extreme homogeneity in risk ratios across studies, using the empiric distribution of the summary risk ratio and heterogeneity statistic. A left-sided P=0.01 threshold was set for claiming extreme homogeneity to minimize type I error. Among 11,803 meta-analyses with binary contrasts from the Cochrane Library, 143 (1.21%) had left-sided P-value <0.01 for the asymptotic Q statistic and 1,004 (8.50%) had left-sided P-value <0.10. The frequency of extreme between-study homogeneity did not depend on the number of studies in the meta-analyses. We identified examples where extreme between-study homogeneity (left-sided P-value <0.01) could result from various possibilities beyond chance. These included inappropriate statistical inference (asymptotic vs. Monte Carlo), use of a specific effect metric, correlated data or stratification using strong predictors of outcome, and biases and potential fraud. Extreme between-study homogeneity may provide useful insights about a meta-analysis and its constituent studies.
Cavalcante, Y L; Hauser-Davis, R A; Saraiva, A C F; Brandão, I L S; Oliveira, T F; Silveira, A M
2013-01-01
This paper compared and evaluated seasonal variations in physico-chemical parameters and metals at a hydroelectric power station reservoir by applying Multivariate Analyses and Artificial Neural Networks (ANN) statistical techniques. A Factor Analysis was used to reduce the number of variables: the first factor was composed of elements Ca, K, Mg and Na, and the second by Chemical Oxygen Demand. The ANN showed 100% correct classifications in training and validation samples. Physico-chemical analyses showed that water pH values were not statistically different between the dry and rainy seasons, while temperature, conductivity, alkalinity, ammonia and DO were higher in the dry period. TSS, hardness and COD, on the other hand, were higher during the rainy season. The statistical analyses showed that Ca, K, Mg and Na are directly connected to the Chemical Oxygen Demand, which indicates a possibility of their input into the reservoir system by domestic sewage and agricultural run-offs. These statistical applications, thus, are also relevant in cases of environmental management and policy decision-making processes, to identify which factors should be further studied and/or modified to recover degraded or contaminated water bodies. Copyright © 2012 Elsevier B.V. All rights reserved.
Design and Execution of make-like, distributed Analyses based on Spotify’s Pipelining Package Luigi
NASA Astrophysics Data System (ADS)
Erdmann, M.; Fischer, B.; Fischer, R.; Rieger, M.
2017-10-01
In high-energy particle physics, workflow management systems are primarily used as tailored solutions in dedicated areas such as Monte Carlo production. However, physicists performing data analyses are usually required to steer their individual workflows manually which is time-consuming and often leads to undocumented relations between particular workloads. We present a generic analysis design pattern that copes with the sophisticated demands of end-to-end HEP analyses and provides a make-like execution system. It is based on the open-source pipelining package Luigi which was developed at Spotify and enables the definition of arbitrary workloads, so-called Tasks, and the dependencies between them in a lightweight and scalable structure. Further features are multi-user support, automated dependency resolution and error handling, central scheduling, and status visualization in the web. In addition to already built-in features for remote jobs and file systems like Hadoop and HDFS, we added support for WLCG infrastructure such as LSF and CREAM job submission, as well as remote file access through the Grid File Access Library. Furthermore, we implemented automated resubmission functionality, software sandboxing, and a command line interface with auto-completion for a convenient working environment. For the implementation of a t \\overline{{{t}}} H cross section measurement, we created a generic Python interface that provides programmatic access to all external information such as datasets, physics processes, statistical models, and additional files and values. In summary, the setup enables the execution of the entire analysis in a parallelized and distributed fashion with a single command.
The factor structure of the Alcohol Use Disorders Identification Test (AUDIT).
Doyle, Suzanne R; Donovan, Dennis M; Kivlahan, Daniel R
2007-05-01
Past research assessing the factor structure of the Alcohol Use Disorders Identification Test (AUDIT) with various exploratory and confirmatory factor analytic techniques has identified one-, two-, and three-factor solutions. Because different factor analytic procedures may result in dissimilar findings, we examined the factor structure of the AUDIT using the same factor analytic technique on two new large clinical samples and on archival data from six samples studied in previous reports. Responses to the AUDIT were obtained from participants who met Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV), criteria for alcohol dependence in two large randomized clinical trials: the COMBINE (Combining Medications and Behavioral Interventions) Study (N = 1,337; 69% men) and Project MATCH (Matching Alcoholism Treatments to Client Heterogeneity; N = 1,711; 76% men). Supplementary analyses involved six correlation matrices of AUDIT data obtained from five previously published articles. Confirmatory factor analyses based on one-, two-, and three-factor models were conducted on the eight correlation matrices to assess the factor structure of the AUDIT. Across samples, analyses supported a correlated, two-factor solution representing alcohol consumption and alcohol-related consequences. The three-factor solution fit the data equally well, but two factors (alcohol dependence and harmful alcohol use) were highly correlated. The one-factor solution did not provide a good fit to the data. These findings support a two-factor solution for the AUDIT (alcohol consumption and alcohol-related consequences). The results contradict the original three-factor design of the AUDIT and the prevalent use of the AUDIT as a one-factor screening instrument with a single cutoff score.
NASA Technical Reports Server (NTRS)
Owens, Andrew; De Weck, Olivier L.; Stromgren, Chel; Goodliff, Kandyce; Cirillo, William
2017-01-01
Future crewed missions to Mars present a maintenance logistics challenge that is unprecedented in human spaceflight. Mission endurance – defined as the time between resupply opportunities – will be significantly longer than previous missions, and therefore logistics planning horizons are longer and the impact of uncertainty is magnified. Maintenance logistics forecasting typically assumes that component failure rates are deterministically known and uses them to represent aleatory uncertainty, or uncertainty that is inherent to the process being examined. However, failure rates cannot be directly measured; rather, they are estimated based on similarity to other components or statistical analysis of observed failures. As a result, epistemic uncertainty – that is, uncertainty in knowledge of the process – exists in failure rate estimates that must be accounted for. Analyses that neglect epistemic uncertainty tend to significantly underestimate risk. Epistemic uncertainty can be reduced via operational experience; for example, the International Space Station (ISS) failure rate estimates are refined using a Bayesian update process. However, design changes may re-introduce epistemic uncertainty. Thus, there is a tradeoff between changing a design to reduce failure rates and operating a fixed design to reduce uncertainty. This paper examines the impact of epistemic uncertainty on maintenance logistics requirements for future Mars missions, using data from the ISS Environmental Control and Life Support System (ECLS) as a baseline for a case study. Sensitivity analyses are performed to investigate the impact of variations in failure rate estimates and epistemic uncertainty on spares mass. The results of these analyses and their implications for future system design and mission planning are discussed.
From sexless to sexy: Why it is time for human genetics to consider and report analyses of sex.
Powers, Matthew S; Smith, Phillip H; McKee, Sherry A; Ehringer, Marissa A
2017-01-01
Science has come a long way with regard to the consideration of sex differences in clinical and preclinical research, but one field remains behind the curve: human statistical genetics. The goal of this commentary is to raise awareness and discussion about how to best consider and evaluate possible sex effects in the context of large-scale human genetic studies. Over the course of this commentary, we reinforce the importance of interpreting genetic results in the context of biological sex, establish evidence that sex differences are not being considered in human statistical genetics, and discuss how best to conduct and report such analyses. Our recommendation is to run stratified analyses by sex no matter the sample size or the result and report the findings. Summary statistics from stratified analyses are helpful for meta-analyses, and patterns of sex-dependent associations may be hidden in a combined dataset. In the age of declining sequencing costs, large consortia efforts, and a number of useful control samples, it is now time for the field of human genetics to appropriately include sex in the design, analysis, and reporting of results.
Pike, Katie; Nash, Rachel L; Murphy, Gavin J; Reeves, Barnaby C; Rogers, Chris A
2015-02-22
The Transfusion Indication Threshold Reduction (TITRe2) trial is the largest randomized controlled trial to date to compare red blood cell transfusion strategies following cardiac surgery. This update presents the statistical analysis plan, detailing how the study will be analyzed and presented. The statistical analysis plan has been written following recommendations from the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use, prior to database lock and the final analysis of trial data. Outlined analyses are in line with the Consolidated Standards of Reporting Trials (CONSORT). The study aims to randomize 2000 patients from 17 UK centres. Patients are randomized to either a restrictive (transfuse if haemoglobin concentration <7.5 g/dl) or liberal (transfuse if haemoglobin concentration <9 g/dl) transfusion strategy. The primary outcome is a binary composite outcome of any serious infectious or ischaemic event in the first 3 months following randomization. The statistical analysis plan details how non-adherence with the intervention, withdrawals from the study, and the study population will be derived and dealt with in the analysis. The planned analyses of the trial primary and secondary outcome measures are described in detail, including approaches taken to deal with multiple testing, model assumptions not being met and missing data. Details of planned subgroup and sensitivity analyses and pre-specified ancillary analyses are given, along with potential issues that have been identified with such analyses and possible approaches to overcome such issues. ISRCTN70923932 .
Lay-led and peer support interventions for adolescents with asthma.
Kew, Kayleigh M; Carr, Robin; Crossingham, Iain
2017-04-19
Adolescents with asthma are at high risk of poor adherence with treatment. This may be compounded by activities that worsen asthma, in particular smoking. Additional support above and beyond routine care has the potential to encourage good self-management. We wanted to find out whether sessions led by their peers or by lay leaders help to reduce these risks and improve asthma outcomes among adolescents. To assess the safety and efficacy of lay-led and peer support interventions for adolescents with asthma. We identified trials from the Cochrane Airways Trials Register, which contains reports of randomised trials obtained from multiple electronic and handsearched sources, and we searched trial registries and reference lists of primary studies. We conducted the most recent searches on 25 November 2016. Eligible studies randomised adolescents with asthma to an intervention led by lay people or peers or to a control. We included parallel randomised controlled trials with individual or cluster designs. We included studies reported as full text, those published as abstract only and unpublished data. Two review authors screened the searches, extracted numerical data and study characteristics and assessed each included study for risk of bias. Primary outcomes were asthma-related quality of life and exacerbations requiring at least a course of oral steroids. We graded the analyses and presented evidence in a 'Summary of findings' table.We analysed dichotomous data as odds ratios, and continuous data as mean differences (MD) or standardised mean differences, all with a random-effects model. We assessed clinical, methodological and statistical heterogeneity when performing meta-analyses, and we described skewed data narratively. Five studies including a total of 1146 participants met the inclusion criteria for this review. As ever with systematic reviews of complex interventions, studies varied by design (cluster and individually randomised), duration (2.5 to 9 months), setting (school, day camp, primary care) and intervention content. Most risk of bias concerns were related to blinding and incomplete reporting, which limited the meta-analyses that could be performed. Studies generally controlled well for selection and attrition biases.All participants were between 11 and 17 years of age. Asthma diagnosis and severity varied, as did smoking prevalence. Three studies used the Triple A programme; one of these studies tested the addition of a smoke-free pledge; another delivered peer support group sessions and mp3 messaging to encourage adherence; and the third compared a peer-led asthma day camp with an equivalent camp led by healthcare practitioners.We had low confidence in all findings owing to risk of bias, inconsistency and imprecision. Results from an analysis of asthma-related quality of life based on the prespecified random-effects model were imprecise and showed no differences (MD 0.40, 95% confidence interval (CI) -0.02 to 0.81); a sensitivity analysis based on a fixed-effect model and a responder analysis suggested small benefit may be derived for this outcome. Most other results were summarised narratively and did not show an important benefit of the intervention; studies provided no analysable data on asthma exacerbations or unscheduled visits (data were skewed), and one study measuring adherence reported a drop in both groups. Effects on asthma control favoured the intervention but findings were not statistically significant. Results from two studies with high levels of baseline smoking showed some promise for self-efficacy to stop smoking, but overall nicotine dependence and smoking-related knowledge were not significantly better in the intervention group. Investigators did not report adverse events. Although weak evidence suggests that lay-led and peer support interventions could lead to a small improvement in asthma-related quality of life for adolescents, benefits for asthma control, exacerbations and medication adherence remain unproven. Current evidence is insufficient to reveal whether routine use of lay-led or peer support programmes is beneficial for adolescents receiving asthma care.Ongoing and future research may help to identify target populations for lay-led and peer support interventions, along with attributes that constitute a successful programme.
Lin, J-D; Yen, C-F; Loh, C-H; Chwo, M-J; Lee, J-T; Wu, J-L; Chu, C M; Tang, C-C
2006-01-01
Little information is available on the provision of supportive health environments for persons with intellectual disabilities (ID) in institutions. The aim of this study was to present an overview of supportive environments for health in institutions in Taiwan. A cross-sectional survey was conducted to examine the perceptions of 121 Taiwanese Institutional Directors on their setting's implementation of supportive healthy physical, social, and economic environments. Analyses showed that first-aid kits (97.5%) and medicine cabinets (85.5%) were the most common health facilities in institutions. Seventy-three per cent of institutions had set up specific areas to be used for rehabilitation practice, while only 43.1% thought their rehabilitation equipment/devices adequate for their real needs. Eighty-eight per cent of institutions implemented health promotion plans for people with ID, while 76.6% had appropriated specific health promotion plans. Sixty-three institutions (52.1%) reported employment of skilled nurses to serve people with ID, and these institutions showed statistically significant differences in implementation of each health facility. The present paper is the first to analyze supportive environments for health in disability institutions in Taiwan. An important focus of future research will be the extension of the present findings to consider the appropriateness of each area of supportive environments for improving the quality of institutional care for people with ID.
Using an online service for breastfeeding support: what mothers want to discuss.
Cowie, Genevieve A; Hill, Sophie; Robinson, Priscilla
2011-08-01
There is little research on how the establishment and maintenance of breastfeeding and other early parenting skills is assisted by the use of electronic peer support groups. In what ways do parents use a popular peer-moderated online resource and what topics do they choose to discuss? The objective of this study was to identify and quantify the main uses of an electronic discussion board hosted by a prominent Australian lay breastfeeding advocacy organisation. Three consecutive days of conversations on the discussion board were followed. Using content analysis, the messages were coded and analysed statistically for the ways the board was used and which topics were and were not present. The discussion board almost universally gave emotional support to the participants and most users expressed their emotions in their messages. The giving of factual advice or opinions was a much less frequent use of the discussion board as was the clear seeking of emotional support and general facts or advice. The range of topics discussed was dominated by general parenting followed by various breastfeeding topics as well as much discussion related to general social support. The lay-moderated discussion board can be a worthwhile resource for parents in need of reassurance, information or general social support. It may also be useful to expand the amount of breastfeeding and parenting information available on the organisation's main website.
Efficiency of nuclear and mitochondrial markers recovering and supporting known amniote groups.
Lambret-Frotté, Julia; Perini, Fernando Araújo; de Moraes Russo, Claudia Augusta
2012-01-01
We have analysed the efficiency of all mitochondrial protein coding genes and six nuclear markers (Adora3, Adrb2, Bdnf, Irbp, Rag2 and Vwf) in reconstructing and statistically supporting known amniote groups (murines, rodents, primates, eutherians, metatherians, therians). The efficiencies of maximum likelihood, Bayesian inference, maximum parsimony, neighbor-joining and UPGMA were also evaluated, by assessing the number of correct and incorrect recovered groupings. In addition, we have compared support values using the conservative bootstrap test and the Bayesian posterior probabilities. First, no correlation was observed between gene size and marker efficiency in recovering or supporting correct nodes. As expected, tree-building methods performed similarly, even UPGMA that, in some cases, outperformed other most extensively used methods. Bayesian posterior probabilities tend to show much higher support values than the conservative bootstrap test, for correct and incorrect nodes. Our results also suggest that nuclear markers do not necessarily show a better performance than mitochondrial genes. The so-called dependency among mitochondrial markers was not observed comparing genome performances. Finally, the amniote groups with lowest recovery rates were therians and rodents, despite the morphological support for their monophyletic status. We suggest that, regardless of the tree-building method, a few carefully selected genes are able to unfold a detailed and robust scenario of phylogenetic hypotheses, particularly if taxon sampling is increased.
Geospatial Characterization of Fluvial Wood Arrangement in a Semi-confined Alluvial River
NASA Astrophysics Data System (ADS)
Martin, D. J.; Harden, C. P.; Pavlowsky, R. T.
2014-12-01
Large woody debris (LWD) has become universally recognized as an integral component of fluvial systems, and as a result, has become increasingly common as a river restoration tool. However, "natural" processes of wood recruitment and the subsequent arrangement of LWD within the river network are poorly understood. This research used a suite of spatial statistics to investigate longitudinal arrangement patterns of LWD in a low-gradient, Midwestern river. First, a large-scale GPS inventory of LWD, performed on the Big River in the eastern Missouri Ozarks, resulted in over 4,000 logged positions of LWD along seven river segments that covered nearly 100 km of the 237 km river system. A global Moran's I analysis indicates that LWD density is spatially autocorrelated and displays a clustering tendency within all seven river segments (P-value range = 0.000 to 0.054). A local Moran's I analysis identified specific locations along the segments where clustering occurs and revealed that, on average, clusters of LWD density (high or low) spanned 400 m. Spectral analyses revealed that, in some segments, LWD density is spatially periodic. Two segments displayed strong periodicity, while the remaining segments displayed varying degrees of noisiness. Periodicity showed a positive association with gravel bar spacing and meander wavelength, although there were insufficient data to statistically confirm the relationship. A wavelet analysis was then performed to investigate periodicity relative to location along the segment. The wavelet analysis identified significant (α = 0.05) periodicity at discrete locations along each of the segments. Those reaches yielding strong periodicity showed stronger relationships between LWD density and the geomorphic/riparian independent variables tested. Analyses consistently identified valley width and sinuosity as being associated with LWD density. The results of these analyses contribute a new perspective on the longitudinal distribution of LWD in a river system, which should help identify physical and/or riparian control mechanisms of LWD arrangement and support the development of models of LWD arrangement. Additionally, the spatial statistical tools presented here have shown to be valuable for identifying longitudinal patterns in river system components.
Haile, Tariku Gebre
2017-01-01
Background. In many studies, compliance with standard precautions among healthcare workers was reported to be inadequate. Objective. The aim of this study was to assess compliance with standard precautions and associated factors among healthcare workers in northwest Ethiopia. Methods. An institution-based cross-sectional study was conducted from March 01 to April 30, 2014. Simple random sampling technique was used to select participants. Data were entered into Epi info 3.5.1 and were exported to SPSS version 20.0 for statistical analysis. Multivariate logistic regression analyses were computed and adjusted odds ratio with 95% confidence interval was calculated to identify associated factors. Results. The proportion of healthcare workers who always comply with standard precautions was found to be 12%. Being a female healthcare worker (AOR [95% CI] 2.18 [1.12–4.23]), higher infection risk perception (AOR [95% CI] 3.46 [1.67–7.18]), training on standard precautions (AOR [95% CI] 2.90 [1.20–7.02]), accessibility of personal protective equipment (AOR [95% CI] 2.87 [1.41–5.86]), and management support (AOR [95% CI] 2.23 [1.11–4.53]) were found to be statistically significant. Conclusion and Recommendation. Compliance with standard precautions among the healthcare workers is very low. Interventions which include training of healthcare workers on standard precautions and consistent management support are recommended. PMID:28191020
[What Surgeons Should Know about Risk Management].
Strametz, R; Tannheimer, M; Rall, M
2017-02-01
Background: The fact that medical treatment is associated with errors has long been recognized. Based on the principle of "first do no harm", numerous efforts have since been made to prevent such errors or limit their impact. However, recent statistics show that these measures do not sufficiently prevent grave mistakes with serious consequences. Preventable mistakes such as wrong patient or wrong site surgery still frequently occur in error statistics. Methods: Based on insight from research on human error, in due consideration of recent legislative regulations in Germany, the authors give an overview of the clinical risk management tools needed to identify risks in surgery, analyse their causes, and determine adequate measures to manage those risks depending on their relevance. The use and limitations of critical incident reporting systems (CIRS), safety checklists and crisis resource management (CRM) are highlighted. Also the rationale for IT systems to support the risk management process is addressed. Results/Conclusion: No single tool of risk management can be effective as a standalone instrument, but unfolds its effect only when embedded in a superordinate risk management system, which integrates tailor-made elements to increase patient safety into the workflows of each organisation. Competence in choosing adequate tools, effective IT systems to support the risk management process as well as leadership and commitment to constructive handling of human error are crucial components to establish a safety culture in surgery. Georg Thieme Verlag KG Stuttgart · New York.
Pereira, Anieli G; Sterli, Juliana; Moreira, Filipe R R; Schrago, Carlos G
2017-08-01
Despite their complex evolutionary history and the rich fossil record, the higher level phylogeny and historical biogeography of living turtles have not been investigated in a comprehensive and statistical framework. To tackle these issues, we assembled a large molecular dataset, maximizing both taxonomic and gene sampling. As different models provide alternative biogeographical scenarios, we have explicitly tested such hypotheses in order to reconstruct a robust biogeographical history of Testudines. We scanned publicly available databases for nucleotide sequences and composed a dataset comprising 13 loci for 294 living species of Testudines, which accounts for all living genera and 85% of their extant species diversity. Phylogenetic relationships and species divergence times were estimated using a thorough evaluation of fossil information as calibration priors. We then carried out the analysis of historical biogeography of Testudines in a fully statistical framework. Our study recovered the first large-scale phylogeny of turtles with well-supported relationships following the topology proposed by phylogenomic works. Our dating result consistently indicated that the origin of the main clades, Pleurodira and Cryptodira, occurred in the early Jurassic. The phylogenetic and historical biogeographical inferences permitted us to clarify how geological events affected the evolutionary dynamics of crown turtles. For instance, our analyses support the hypothesis that the breakup of Pangaea would have driven the divergence between the cryptodiran and pleurodiran lineages. The reticulated pattern in the ancestral distribution of the cryptodiran lineage suggests a complex biogeographic history for the clade, which was supposedly related to the complex paleogeographic history of Laurasia. On the other hand, the biogeographical history of Pleurodira indicated a tight correlation with the paleogeography of the Gondwanan landmasses. Copyright © 2017 Elsevier Inc. All rights reserved.
Factors influencing initiation and duration of breast feeding in Ireland.
Leahy-Warren, Patricia; Mulcahy, Helen; Phelan, Agnes; Corcoran, Paul
2014-03-01
The aim of this research was to identify factors associated with mothers breast feeding and to identify, for those who breast fed, factors associated with breast feeding for as long as planned. breast feeding rates in Ireland are amongst the lowest in Europe. Research evidence indicates that in order for mothers to be successful at breast feeding, multiplicities of supports are necessary for both initiation and duration. The nature of these supports in tandem with other influencing factors requires analysis from an Irish perspective. cross-sectional study involving public health nurses and mothers in Ireland. This paper presents the results of the mothers' evaluation. mothers (n=1715) with children less than three years were offered a choice of completing the self-report questionnaires online or by mail. Data were analysed and reported using descriptive and inferential statistics. four in every five participants breast fed their infant and two thirds of them breast fed as long as planned. The multivariate logistic regression analysis identified that third level education, being a first time mother or previously having breast fed, participating online, having more than two public health nurse visits, and having a positive infant feeding attitude were independently and statistically significantly associated with breast feeding. Among mothers who breast fed, being aged at least 35 years, participating online, having a positive infant feeding attitude and high breast feeding self-efficacy were independently and statistically significantly associated with breast feeding for as long as planned. findings from this study reinforce health inequalities therefore there needs to be a renewed commitment to reducing health inequalities in relation to breast feeding. this study has identified factors associated with initiation and duration of breast feeding that are potentially modifiable through public health interventions. Copyright © 2013 Elsevier Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Loftus, K.; Saar, S. H.
2017-12-01
NOAA's Space Weather Prediction Center publishes the current definitive public soft X-ray flare catalog, derived using data from the X-ray Sensor (XRS) on the Geostationary Operational Environmental Satellites (GOES) series. However, this flare list has shortcomings for use in scientific analysis. Its detection algorithm has drawbacks (missing smaller flux events and poorly characterizing complex ones), and its event timing is imprecise (peak and end times are frequently marked incorrectly, and hence peak fluxes are underestimated). It also lacks explicit and regular spatial location data. We present a new database, "The Where of the Flare" catalog, which improves upon the precision of NOAA's current version, with more consistent and accurate spatial locations, timings, and peak fluxes. Our catalog also offers several new parameters per flare (e.g. background flux, integrated flux). We use data from the GOES Solar X-ray Imager (SXI) for spatial flare locating. Our detection algorithm is more sensitive to smaller flux events close to the background level and more precisely marks flare start/peak/end times so that integrated flux can be accurately calculated. It also decomposes complex events (with multiple overlapping flares) by constituent peaks. The catalog dates from the operation of the first SXI instrument in 2003 until the present. We give an overview of the detection algorithm's design, review the catalog's features, and discuss preliminary statistical analyses of light curve morphology, complex event decomposition, and integrated flux distribution. The Where of the Flare catalog will be useful in studying X-ray flare statistics and correlating X-ray flare properties with other observations. This work was supported by Contract #8100002705 from Lockheed-Martin to SAO in support of the science of NASA's IRIS mission.
NASA Astrophysics Data System (ADS)
Li, Xiaohui; Yang, Sibo; Fan, Rongwei; Yu, Xin; Chen, Deying
2018-06-01
In this paper, discrimination of soft tissues using laser-induced breakdown spectroscopy (LIBS) in combination with multivariate statistical methods is presented. Fresh pork fat, skin, ham, loin and tenderloin muscle tissues are manually cut into slices and ablated using a 1064 nm pulsed Nd:YAG laser. Discrimination analyses between fat, skin and muscle tissues, and further between highly similar ham, loin and tenderloin muscle tissues, are performed based on the LIBS spectra in combination with multivariate statistical methods, including principal component analysis (PCA), k nearest neighbors (kNN) classification, and support vector machine (SVM) classification. Performances of the discrimination models, including accuracy, sensitivity and specificity, are evaluated using 10-fold cross validation. The classification models are optimized to achieve best discrimination performances. The fat, skin and muscle tissues can be definitely discriminated using both kNN and SVM classifiers, with accuracy of over 99.83%, sensitivity of over 0.995 and specificity of over 0.998. The highly similar ham, loin and tenderloin muscle tissues can also be discriminated with acceptable performances. The best performances are achieved with SVM classifier using Gaussian kernel function, with accuracy of 76.84%, sensitivity of over 0.742 and specificity of over 0.869. The results show that the LIBS technique assisted with multivariate statistical methods could be a powerful tool for online discrimination of soft tissues, even for tissues of high similarity, such as muscles from different parts of the animal body. This technique could be used for discrimination of tissues suffering minor clinical changes, thus may advance the diagnosis of early lesions and abnormalities.
Li, Huanjie; Nickerson, Lisa D; Nichols, Thomas E; Gao, Jia-Hong
2017-03-01
Two powerful methods for statistical inference on MRI brain images have been proposed recently, a non-stationary voxelation-corrected cluster-size test (CST) based on random field theory and threshold-free cluster enhancement (TFCE) based on calculating the level of local support for a cluster, then using permutation testing for inference. Unlike other statistical approaches, these two methods do not rest on the assumptions of a uniform and high degree of spatial smoothness of the statistic image. Thus, they are strongly recommended for group-level fMRI analysis compared to other statistical methods. In this work, the non-stationary voxelation-corrected CST and TFCE methods for group-level analysis were evaluated for both stationary and non-stationary images under varying smoothness levels, degrees of freedom and signal to noise ratios. Our results suggest that, both methods provide adequate control for the number of voxel-wise statistical tests being performed during inference on fMRI data and they are both superior to current CSTs implemented in popular MRI data analysis software packages. However, TFCE is more sensitive and stable for group-level analysis of VBM data. Thus, the voxelation-corrected CST approach may confer some advantages by being computationally less demanding for fMRI data analysis than TFCE with permutation testing and by also being applicable for single-subject fMRI analyses, while the TFCE approach is advantageous for VBM data. Hum Brain Mapp 38:1269-1280, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.
Macfarlane, Sarah B.
2005-01-01
Efforts to strengthen health information systems in low- and middle-income countries should include forging links with systems in other social and economic sectors. Governments are seeking comprehensive socioeconomic data on the basis of which to implement strategies for poverty reduction and to monitor achievement of the Millennium Development Goals. The health sector is looking to take action on the social factors that determine health outcomes. But there are duplications and inconsistencies between sectors in the collection, reporting, storage and analysis of socioeconomic data. National offices of statistics give higher priority to collection and analysis of economic than to social statistics. The Report of the Commission for Africa has estimated that an additional US$ 60 million a year is needed to improve systems to collect and analyse statistics in Africa. Some donors recognize that such systems have been weakened by numerous international demands for indicators, and have pledged support for national initiatives to strengthen statistical systems, as well as sectoral information systems such as those in health and education. Many governments are working to coordinate information systems to monitor and evaluate poverty reduction strategies. There is therefore an opportunity for the health sector to collaborate with other sectors to lever international resources to rationalize definition and measurement of indicators common to several sectors; streamline the content, frequency and timing of household surveys; and harmonize national and subnational databases that store socioeconomic data. Without long-term commitment to improve training and build career structures for statisticians and information technicians working in the health and other sectors, improvements in information and statistical systems cannot be sustained. PMID:16184278
PCA as a practical indicator of OPLS-DA model reliability.
Worley, Bradley; Powers, Robert
Principal Component Analysis (PCA) and Orthogonal Projections to Latent Structures Discriminant Analysis (OPLS-DA) are powerful statistical modeling tools that provide insights into separations between experimental groups based on high-dimensional spectral measurements from NMR, MS or other analytical instrumentation. However, when used without validation, these tools may lead investigators to statistically unreliable conclusions. This danger is especially real for Partial Least Squares (PLS) and OPLS, which aggressively force separations between experimental groups. As a result, OPLS-DA is often used as an alternative method when PCA fails to expose group separation, but this practice is highly dangerous. Without rigorous validation, OPLS-DA can easily yield statistically unreliable group separation. A Monte Carlo analysis of PCA group separations and OPLS-DA cross-validation metrics was performed on NMR datasets with statistically significant separations in scores-space. A linearly increasing amount of Gaussian noise was added to each data matrix followed by the construction and validation of PCA and OPLS-DA models. With increasing added noise, the PCA scores-space distance between groups rapidly decreased and the OPLS-DA cross-validation statistics simultaneously deteriorated. A decrease in correlation between the estimated loadings (added noise) and the true (original) loadings was also observed. While the validity of the OPLS-DA model diminished with increasing added noise, the group separation in scores-space remained basically unaffected. Supported by the results of Monte Carlo analyses of PCA group separations and OPLS-DA cross-validation metrics, we provide practical guidelines and cross-validatory recommendations for reliable inference from PCA and OPLS-DA models.
Temporal distribution of floods and landslides in Portugal (1865-2010)
NASA Astrophysics Data System (ADS)
Santos, Monica; Bateira, Carlos; Hermenegildo, Carlos; Soares, Laura; Pereira, Susana; Quaresma, Ivânia; Santos, Pedro
2013-04-01
Hydro-geomorphological events are the natural hazards that most affect Portugal. Under the DISASTER research project, was created a GIS database (DB) about floods and landslides that occurred in this country, from 1865 to 2010. The inventory of these processes was based on a systematic compilation of national and regional newspapers articles, focusing occurrences with direct consequences on the population, i.e., those that implied killed, injured, missing, evacuated or displaced people, independently of the number of affected and the economic value of damage. The main objective of this DB is to support the development of risk studies related with these events, analysing their spatial and temporal distribution, the susceptibility of the territories and the vulnerability of the exposed elements. It is essential for risk management, providing a decision support for spatial and emergency planning. This study aims to analyse the temporal rhythm of floods and landslides that occurred in the above mentioned period, as well as its evolutionary trend and the relationship between these processes and the precipitation, the main triggering factor of hydro-geomorphological events in Portugal mainland. The trends are analysed using the nonparametric Mann-Kendall (M-K) and Theil-Sen statistical tests (B), in order to estimate its magnitude. The results show that from the 1903 records integrated in the Disaster DB (in the 145 years under analysis), 85.2% of occurrences correspond to floods and 14.8% to landslides. Until 1935 the number of occurrences per year is less than 10 (except 1909), but after this date there was a significant increase of this value, mainly in the years of 1936, 1966/67, 1979, 1996 and 2001, with more than 50 occurrences/year. In the period between 1935 and 1975, the mean number of occurrences is 22.5/year, but between 1975-2010 it changes to 16.5. The results suggest the absence of a statistically significant increasing trend of occurrences, during all the analysed period. Instead, these processes seem to report a cyclical behaviour considering different time scales, evidenced also by the precipitation data, highlighting the period from 1935 to 1975, with the highest number of occurrences. In fact, the mean annual precipitation (MAP) and mean daily intensity (MDI) variables also seem to reveal a cyclic trend, corresponding the years with the highest number of occurrences to those with higher MAP and MDI values, although more prominent in the latter one (except in 1909), evidencing the influence that precipitation has on the floods and landslide processes.
Kerridge, Bradley T.; Saha, Tulshi D.; Smith, Sharon; Chou, Patricia S.; Pickering, Roger P.; Huang, Boji; Ruan, June W.; Pulay, Attila J.
2012-01-01
Background Prior research has demonstrated the dimensionality of Diagnostic and Statistical Manual of Mental Disorders - Fourth Edition (DSM-IV) alcohol, nicotine, cannabis, cocaine and amphetamine abuse and dependence criteria. The purpose of this study was to examine the dimensionality of hallucinogen and inhalant/solvent abuse and dependence criteria. In addition, we assessed the impact of elimination of the legal problems abuse criterion on the information value of the aggregate abuse and dependence criteria, another proposed change for DSM- IV currently lacking empirical justification. Methods Factor analyses and item response theory (IRT) analyses were used to explore the unidimisionality and psychometric properties of hallucinogen and inhalant/solvent abuse and dependence criteria using a large representative sample of the United States (U.S.) general population. Results Hallucinogen and inhalant/solvent abuse and dependence criteria formed unidimensional latent traits. For both substances, IRT models without the legal problems abuse criterion demonstrated better fit than the corresponding model with the legal problem abuse criterion. Further, there were no differences in the information value of the IRT models with and without the legal problems abuse criterion, supporting the elimination of that criterion. No bias in the new diagnoses was observed by sex, age and race-ethnicity. Conclusion Consistent with findings for alcohol, nicotine, cannabis, cocaine and amphetamine abuse and dependence criteria, hallucinogen and inhalant/solvent criteria reflect underlying dimensions of severity. The legal problems criterion associated with each of these substance use disorders can be eliminated with no loss in informational value and an advantage of parsimony. Taken together, these findings support the changes to substance use disorder diagnoses recommended by the DSM-V Substance and Related Disorders Workgroup, that is, combining DSM-IV abuse and dependence criteria and eliminating the legal problems abuse criterion. PMID:21621334
NASA Astrophysics Data System (ADS)
Okech, Allan P.
The purpose of the study was to examine the relationships among emotional intelligence, teacher self-efficacy, length of teaching experience, and age in a sample of south Texas public school teachers. Additionally, the study examined differences in emotional intelligence between male teachers and female teachers, and among African American, Hispanics, and White teachers. Participants were 180 elementary science teachers from south Texas public schools. The sample was made up of 14 (7.8%) males and 166 (92.2%) females. Regarding race/ethnicity, the study sample consisted of 31 (17.2%) African Americans (3 males and 28 females), 49 (27.2) Hispanics (7 males and 42 females), 98 (54.4%) Whites (3 males and 95 females), and 2 (1.1%) "Other" (1 male and 1 female). Participants ranged in age from 23 years to 65 years. Five hypotheses were proposed and tested to address the relationships under investigation. The study employed a mixed methods---correlational and causal-comparative---research design approach. Three instruments, the Multifactor Emotional Intelligence Scale (Mayer, Caruso, & Salovey, 1999), the Science Teaching Efficacy Beliefs Instrument (Riggs & Enochs, 1990), and a demographics questionnaire were utilized to collect the data. An independent-measures t test, the Pearson r, and the one-way MANOVA were used to analyze the data. A Significant positive relationship was found between "emotional intelligence" and "teacher self-efficacy." Data analyses, however, failed to support hypothesized relationships between "emotional intelligence" and "length of teaching experience," and between "emotional intelligence" and "age". Additionally, statistical analyses of the data collected for this study supported predicted statistically significant differences in "emotional intelligence" between male and female teachers, and among the three race/ethnicity groupings. Based on these findings, recommendations for the application of the construct of "emotional intelligence" in Texas public schools are discussed.
Kerridge, Bradley T; Saha, Tulshi D; Smith, Sharon; Chou, Patricia S; Pickering, Roger P; Huang, Boji; Ruan, June W; Pulay, Attila J
2011-09-01
Prior research has demonstrated the dimensionality of Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition (DSM-IV) alcohol, nicotine, cannabis, cocaine and amphetamine abuse and dependence criteria. The purpose of this study was to examine the dimensionality of hallucinogen and inhalant/solvent abuse and dependence criteria. In addition, we assessed the impact of elimination of the legal problems abuse criterion on the information value of the aggregate abuse and dependence criteria, another proposed change for DSM-IV currently lacking empirical justification. Factor analyses and item response theory (IRT) analyses were used to explore the unidimisionality and psychometric properties of hallucinogen and inhalant/solvent abuse and dependence criteria using a large representative sample of the United States (U.S.) general population. Hallucinogen and inhalant/solvent abuse and dependence criteria formed unidimensional latent traits. For both substances, IRT models without the legal problems abuse criterion demonstrated better fit than the corresponding model with the legal problem abuse criterion. Further, there were no differences in the information value of the IRT models with and without the legal problems abuse criterion, supporting the elimination of that criterion. No bias in the new diagnoses was observed by sex, age and race-ethnicity. Consistent with findings for alcohol, nicotine, cannabis, cocaine and amphetamine abuse and dependence criteria, hallucinogen and inhalant/solvent criteria reflect underlying dimensions of severity. The legal problems criterion associated with each of these substance use disorders can be eliminated with no loss in informational value and an advantage of parsimony. Taken together, these findings support the changes to substance use disorder diagnoses recommended by the DSM-V Substance and Related Disorders Workgroup, that is, combining DSM-IV abuse and dependence criteria and eliminating the legal problems abuse criterion. Published by Elsevier Ltd.
Conceptual and statistical problems associated with the use of diversity indices in ecology.
Barrantes, Gilbert; Sandoval, Luis
2009-09-01
Diversity indices, particularly the Shannon-Wiener index, have extensively been used in analyzing patterns of diversity at different geographic and ecological scales. These indices have serious conceptual and statistical problems which make comparisons of species richness or species abundances across communities nearly impossible. There is often no a single statistical method that retains all information needed to answer even a simple question. However, multivariate analyses could be used instead of diversity indices, such as cluster analyses or multiple regressions. More complex multivariate analyses, such as Canonical Correspondence Analysis, provide very valuable information on environmental variables associated to the presence and abundance of the species in a community. In addition, particular hypotheses associated to changes in species richness across localities, or change in abundance of one, or a group of species can be tested using univariate, bivariate, and/or rarefaction statistical tests. The rarefaction method has proved to be robust to standardize all samples to a common size. Even the simplest method as reporting the number of species per taxonomic category possibly provides more information than a diversity index value.
The care unit in nursing home research: Evidence in support of a definition
2011-01-01
Background Defining what constitutes a resident care unit in nursing home research is both a conceptual and practical challenge. The aim of this paper is to provide evidence in support of a definition of care unit in nursing homes by demonstrating: (1) its feasibility for use in data collection, (2) the acceptability of aggregating individual responses to the unit level, and (3) the benefit of including unit level data in explanatory models. Methods An observational study design was used. Research (project) managers, healthcare aides, care managers, nursing home administrators and directors of care from thirty-six nursing homes in the Canadian prairie provinces of Alberta, Saskatchewan and Manitoba provided data for the study. A definition of care unit was developed and applied in data collection and analyses. A debriefing session was held with research managers to investigate their experiences with using the care unit definition. In addition, survey responses from 1258 healthcare aides in 25 of the 36 nursing homes in the study, that had more than one care unit, were analyzed using a multi-level modeling approach. Trained field workers administered the Alberta Context Tool (ACT), a 58-item self-report survey reflecting 10 organizational context concepts, to healthcare aides using computer assisted personal interviews. To assess the appropriateness of obtaining unit level scores, we assessed aggregation statistics (ICC(1), ICC(2), η2, and ω2), and to assess the value of using the definition of unit in explanatory models, we performed multi-level modeling. Results In 10 of the 36 nursing homes, the care unit definition developed was used to align the survey data (for analytic purposes) to specific care units as designated by our definition, from that reported by the facility administrator. The aggregation statistics supported aggregating the healthcare aide responses on the ACT to the realigned unit level. Findings from the multi-level modeling further supported unit level aggregation. A significantly higher percentage of variance was explained in the ACT concepts at the unit level compared to the individual and/or nursing home levels. Conclusions The statistical results support the use of our definition of care unit in nursing home research in the Canadian prairie provinces. Beyond research convenience however, the results also support the resident unit as an important Clinical Microsystem to which future interventions designed to improve resident quality of care and staff (healthcare aide) worklife should be targeted. PMID:21492456
Osterholt, Dawn M; Onikpo, Faustin; Lama, Marcel; Deming, Michael S; Rowe, Alexander K
2009-01-01
Background Pneumonia is a leading cause of death among children under five years of age. The Integrated Management of Childhood Illness strategy can improve the quality of care for pneumonia and other common illnesses in developing countries, but adherence to these guidelines could be improved. We evaluated an intervention in Benin to support health worker adherence to the guidelines after training, focusing on pneumonia case management. Methods We conducted a randomized trial. After a health facility survey in 1999 to assess health care quality before Integrated Management of Childhood Illness training, health workers received training plus either study supports (job aids, non-financial incentives and supervision of workers and supervisors) or "usual" supports. Follow-up surveys were conducted in 2001, 2002 and 2004. Outcomes were indicators of health care quality for Integrated Management-defined pneumonia. Further analyses included a graphical pathway analysis and multivariable logistic regression modelling to identify factors influencing case-management quality. Results We observed 301 consultations of children with non-severe pneumonia that were performed by 128 health workers in 88 public and private health facilities. Although outcomes improved in both intervention and control groups, we found no statistically significant difference between groups. However, training proceeded slowly, and low-quality care from untrained health workers diluted intervention effects. Per-protocol analyses suggested that health workers with training plus study supports performed better than those with training plus usual supports (20.4 and 19.2 percentage-point improvements for recommended treatment [p = 0.08] and "recommended or adequate" treatment [p = 0.01], respectively). Both groups tended to perform better than untrained health workers. Analyses of treatment errors revealed that incomplete assessment and difficulties processing clinical findings led to missed pneumonia diagnoses, and missed diagnoses led to inadequate treatment. Increased supervision frequency was associated with better care (odds ratio for recommended treatment = 2.1 [95% confidence interval: 1.1-3.9] per additional supervisory visit). Conclusion Integrated Management of Childhood Illness training was useful, but insufficient, to achieve high-quality pneumonia case management. Our study supports led to additional improvements, although large gaps in performance still remained. A simple graphical pathway analysis can identify specific, common errors that health workers make in the case-management process; this information could be used to target quality improvement activities, such as supervision (ClinicalTrials.gov number NCT00510679). PMID:19712484
NASA Technical Reports Server (NTRS)
Morrissey, L. A.; Weinstock, K. J.; Mouat, D. A.; Card, D. H.
1984-01-01
An evaluation of Thematic Mapper Simulator (TMS) data for the geobotanical discrimination of rock types based on vegetative cover characteristics is addressed in this research. A methodology for accomplishing this evaluation utilizing univariate and multivariate techniques is presented. TMS data acquired with a Daedalus DEI-1260 multispectral scanner were integrated with vegetation and geologic information for subsequent statistical analyses, which included a chi-square test, an analysis of variance, stepwise discriminant analysis, and Duncan's multiple range test. Results indicate that ultramafic rock types are spectrally separable from nonultramafics based on vegetative cover through the use of statistical analyses.
[Clinical research=design*measurements*statistical analyses].
Furukawa, Toshiaki
2012-06-01
A clinical study must address true endpoints that matter for the patients and the doctors. A good clinical study starts with a good clinical question. Formulating a clinical question in the form of PECO can sharpen one's original question. In order to perform a good clinical study one must have a knowledge of study design, measurements and statistical analyses: The first is taught by epidemiology, the second by psychometrics and the third by biostatistics.
Orsini, C; Binnie, V; Wilson, S; Villegas, M J
2018-05-01
The aim of this study was to test the mediating role of the satisfaction of dental students' basic psychological needs of autonomy, competence and relatedness on the association between learning climate, feedback and student motivation. The latter was based on the self-determination theory's concepts of differentiation of autonomous motivation, controlled motivation and amotivation. A cross-sectional correlational study was conducted where 924 students completed self-reported questionnaires measuring motivation, perception of the learning climate, feedback and basic psychological needs satisfaction. Descriptive statistics, Cronbach's alpha scores and bivariate correlations were computed. Mediation of basic needs on each predictor-outcome association was tested based on a series of regression analyses. Finally, all variables were integrated into one structural equation model, controlling for the effects of age, gender and year of study. Cronbach's alpha scores were acceptable (.655 to .905). Correlation analyses showed positive and significant associations between both an autonomy-supportive learning climate and the quantity and quality of feedback received, and students' autonomous motivation, which decreased and became negative when correlated with controlled motivation and amotivation, respectively. Regression analyses revealed that these associations were indirect and mediated by how these predictors satisfied students' basic psychological needs. These results were corroborated by the structural equation analysis, in which data fit the model well and regression paths were in the expected direction. An autonomy-supportive learning climate and the quantity and quality of feedback were positive predictors of students' autonomous motivation and negative predictors of amotivation. However, this was an indirect association mediated by the satisfaction of students' basic psychological needs. Consequently, supporting students' needs of autonomy, competence and relatedness might lead to optimal types of motivation, which has an important influence on dental education. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
ERIC Educational Resources Information Center
Hoeken, Hans; Hustinx, Lettica
2009-01-01
Under certain conditions, statistical evidence is more persuasive than anecdotal evidence in supporting a claim about the probability that a certain event will occur. In three experiments, it is shown that the type of argument is an important condition in this respect. If the evidence is part of an argument by generalization, statistical evidence…
ERIC Educational Resources Information Center
Gratz, Zandra S.; And Others
A study was conducted at a large, state-supported college in the Northeast to establish a mechanism by which a popular software package, Statistical Package for the Social Sciences (SPSS), could be used in psychology program statistics courses in such a way that no prior computer expertise would be needed on the part of the faculty or the…
Nimptsch, Ulrike; Wengler, Annelene; Mansky, Thomas
2016-11-01
In Germany, nationwide hospital discharge data (DRG statistics provided by the research data centers of the Federal Statistical Office and the Statistical Offices of the 'Länder') are increasingly used as data source for health services research. Within this data hospitals can be separated via their hospital identifier ([Institutionskennzeichen] IK). However, this hospital identifier primarily designates the invoicing unit and is not necessarily equivalent to one hospital location. Aiming to investigate direction and extent of possible bias in hospital-level analyses this study examines the continuity of the hospital identifier within a cross-sectional and longitudinal approach and compares the results to official hospital census statistics. Within the DRG statistics from 2005 to 2013 the annual number of hospitals as classified by hospital identifiers was counted for each year of observation. The annual number of hospitals derived from DRG statistics was compared to the number of hospitals in the official census statistics 'Grunddaten der Krankenhäuser'. Subsequently, the temporal continuity of hospital identifiers in the DRG statistics was analyzed within cohorts of hospitals. Until 2013, the annual number of hospital identifiers in the DRG statistics fell by 175 (from 1,725 to 1,550). This decline affected only providers with small or medium case volume. The number of hospitals identified in the DRG statistics was lower than the number given in the census statistics (e.g., in 2013 1,550 IK vs. 1,668 hospitals in the census statistics). The longitudinal analyses revealed that the majority of hospital identifiers persisted in the years of observation, while one fifth of hospital identifiers changed. In cross-sectional studies of German hospital discharge data the separation of hospitals via the hospital identifier might lead to underestimating the number of hospitals and consequential overestimation of caseload per hospital. Discontinuities of hospital identifiers over time might impair the follow-up of hospital cohorts. These limitations must be taken into account in analyses of German hospital discharge data focusing on the hospital level. Copyright © 2016. Published by Elsevier GmbH.
Randich, Erik; Grant, Patrick M
2006-07-01
The bullet evidence in the JFK assassination investigation was reexamined from metallurgical and statistical standpoints. The questioned specimens are comprised of soft lead, possibly from full-metal-jacketed Mannlicher-Carcano (MC), 6.5-mm ammunition. During lead refining, contaminant elements are removed to specified levels for a desired alloy or composition. Microsegregation of trace and minor elements during lead casting and processing can account for the experimental variabilities measured in various evidentiary and comparison samples by laboratory analysts. Thus, elevated concentrations of antimony and copper at crystallographic grain boundaries, the widely varying sizes of grains in MC bullet lead, and the 5-60 mg bullet samples analyzed for assassination intelligence effectively resulted in operational sampling error for the analyses. This deficiency was not considered in the original data interpretation and resulted in an invalid conclusion in favor of the single-bullet theory of the assassination. Alternate statistical calculations, based on the historic analytical data, incorporating weighted averaging and propagation of experimental uncertainties also considerably weaken support for the single-bullet theory. In effect, this assessment of the material composition of the lead specimens from the assassination concludes that the extant evidence is consistent with any number between two and five rounds fired in Dealey Plaza during the shooting.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Randich, E; Grant, P M
2006-08-29
The bullet evidence in the JFK assassination investigation was reexamined from metallurgical and statistical standpoints. The questioned specimens are comprised of soft lead, possibly from full-metal-jacketed Mannlicher-Carcano, 6.5-mm ammunition. During lead refining, contaminant elements are removed to specified levels for a desired alloy or composition. Microsegregation of trace and minor elements during lead casting and processing can account for the experimental variabilities measured in various evidentiary and comparison samples by laboratory analysts. Thus, elevated concentrations of antimony and copper at crystallographic grain boundaries, the widely varying sizes of grains in Mannlicher-Carcano bullet lead, and the 5-60 mg bullet samples analyzedmore » for assassination intelligence effectively resulted in operational sampling error for the analyses. This deficiency was not considered in the original data interpretation and resulted in an invalid conclusion in favor of the single-bullet theory of the assassination. Alternate statistical calculations, based on the historic analytical data, incorporating weighted averaging and propagation of experimental uncertainties also considerably weaken support for the single-bullet theory. In effect, this assessment of the material composition of the lead specimens from the assassination concludes that the extant evidence is consistent with any number between two and five rounds fired in Dealey Plaza during the shooting.« less
easyGWAS: A Cloud-Based Platform for Comparing the Results of Genome-Wide Association Studies.
Grimm, Dominik G; Roqueiro, Damian; Salomé, Patrice A; Kleeberger, Stefan; Greshake, Bastian; Zhu, Wangsheng; Liu, Chang; Lippert, Christoph; Stegle, Oliver; Schölkopf, Bernhard; Weigel, Detlef; Borgwardt, Karsten M
2017-01-01
The ever-growing availability of high-quality genotypes for a multitude of species has enabled researchers to explore the underlying genetic architecture of complex phenotypes at an unprecedented level of detail using genome-wide association studies (GWAS). The systematic comparison of results obtained from GWAS of different traits opens up new possibilities, including the analysis of pleiotropic effects. Other advantages that result from the integration of multiple GWAS are the ability to replicate GWAS signals and to increase statistical power to detect such signals through meta-analyses. In order to facilitate the simple comparison of GWAS results, we present easyGWAS, a powerful, species-independent online resource for computing, storing, sharing, annotating, and comparing GWAS. The easyGWAS tool supports multiple species, the uploading of private genotype data and summary statistics of existing GWAS, as well as advanced methods for comparing GWAS results across different experiments and data sets in an interactive and user-friendly interface. easyGWAS is also a public data repository for GWAS data and summary statistics and already includes published data and results from several major GWAS. We demonstrate the potential of easyGWAS with a case study of the model organism Arabidopsis thaliana , using flowering and growth-related traits. © 2016 American Society of Plant Biologists. All rights reserved.
[Health Statistics in Senegal: between political stakes and role playing].
Hane, Fatoumata
2017-01-01
Many countries have developed disease surveillance systems to deal with epidemics, but although health information systems have existed for more than two decades, constraints and biases in data collection limit the relevance of policy decisions and strategies in the field of health, as priority has been given to education and health in developing countries. Donor support has led to the development of systems for the production of statistics, designed, among other things, to more clearly target interventions in terms of educational objectives, action and credibility and enable health systems to continue to benefit from external funding. We used a classical anthropology approach based on observations and in-depth interviews with local and national health system actors. The aim of this article is to analyse the real effects of the production of health statistics in health care systems and to determine the relevance of these figures in the context in which they apply. Health priorities defined by international organizations and technical and financial partners focus on diseases considered to be ?priorities? to the detriment of neglected diseases, which are perceived as being more important at the local level due to their impact on the already limited health systems. We describe how health actors within healthcare structures adjust and adapt to public health requirements.
Kähkönen, Outi; Kankkunen, Päivi; Miettinen, Heikki; Lamidi, Marja-Leena; Saaranen, Terhi
2017-05-01
To describe perceived social support among patients with coronary heart disease following percutaneous coronary intervention. A low level of social support is considered a risk factor for coronary heart disease in healthy individuals and reduces the likelihood that people diagnosed with coronary heart disease will have a good prognosis. A descriptive cross-sectional study. A survey of 416 patients was conducted in 2013. A self-report instrument, Social Support of People with Coronary Heart Disease, was used. The instrument comprises three dimensions of social support: informational, emotional, functional supports and 16 background variables. Data were analysed using descriptive statistics, factor analysis, mean sum variables and multivariate logistic regression. Perceived informational support was primarily high, but respondents' risk factors were not at the target level. The weakest items of informational support were advice on physical activity, continuum of care and rehabilitation. Regarding the items of emotional support, support from other cardiac patients was the weakest. The weakest item of functional support was respondents' sense of the healthcare professionals' care of patients coping with their disease. Background variables associated with perceived social support were gender, marital status, level of formal education, profession, physical activity, duration of coronary heart disease and previous myocardial infarction. Healthcare professionals should pay extra attention to women, single patients, physically inactive patients, those demonstrating a lower level of education, those with a longer duration of CHD, and respondents without previous acute myocardial infarction. Continuum of care and counselling are important to ensure especially among them. This study provides evidence that healthcare professionals should be more aware of the individual needs for social support among patients with coronary heart disease after percutaneous coronary intervention. © 2016 John Wiley & Sons Ltd.
Han, Kyunghwa; Jung, Inkyung
2018-05-01
This review article presents an assessment of trends in statistical methods and an evaluation of their appropriateness in articles published in the Archives of Plastic Surgery (APS) from 2012 to 2017. We reviewed 388 original articles published in APS between 2012 and 2017. We categorized the articles that used statistical methods according to the type of statistical method, the number of statistical methods, and the type of statistical software used. We checked whether there were errors in the description of statistical methods and results. A total of 230 articles (59.3%) published in APS between 2012 and 2017 used one or more statistical method. Within these articles, there were 261 applications of statistical methods with continuous or ordinal outcomes, and 139 applications of statistical methods with categorical outcome. The Pearson chi-square test (17.4%) and the Mann-Whitney U test (14.4%) were the most frequently used methods. Errors in describing statistical methods and results were found in 133 of the 230 articles (57.8%). Inadequate description of P-values was the most common error (39.1%). Among the 230 articles that used statistical methods, 71.7% provided details about the statistical software programs used for the analyses. SPSS was predominantly used in the articles that presented statistical analyses. We found that the use of statistical methods in APS has increased over the last 6 years. It seems that researchers have been paying more attention to the proper use of statistics in recent years. It is expected that these positive trends will continue in APS.
EXO-DAT: AN INFORMATION SYSTEM IN SUPPORT OF THE CoRoT/EXOPLANET SCIENCE
DOE Office of Scientific and Technical Information (OSTI.GOV)
Deleuil, M.; Meunier, J. C.; Moutou, C.
2009-08-15
Exo-Dat is a database and an information system created primarily in support of the exoplanet program of the COnvection ROtation and planetary Transits (CoRoT) mission. In the directions of CoRoT pointings, it provides a united interface to several sets of data: stellar published catalogs, photometric and spectroscopic data obtained during the mission preparation, results from the mission and from follow-up observations, and several mission-specific technical parameters. The new photometric data constitute the subcatalog Exo-Cat, and give consistent 4-color photometry of 14.0 million stars with a completeness to 19th magnitude in the r-filter. It covers several zones in the galactic planemore » around CoRoT pointings, with a total area of 209 deg{sup 2}. This Exo-Dat information system provides essential technical support to the ongoing CoRoT light-curve analyses and ground-based follow-up by supplying additional complementary information such as the prior knowledge of the star's fundamental parameters or its contamination level inside the large CoRoT photometric mask. The database is fully interfaced with VO tools and thus benefits from existing visualization and analysis tools like TOPCAT or ALADIN. It is accessible to the CoRoT community through the Web, and will be gradually opened to the public. It is the ideal tool to prepare the foreseen statistical studies of the properties of the exoplanetary systems. As a VO-compliant system, such analyses could thus benefit from the most up-to-date classifier tools.« less
Mun, Chung Jung; Tein, Jenn-Yun; Kim, Hanjoe; Shaw, Daniel S.; Gardner, Frances; Wilson, Melvin N.; Peterson, Jenene
2018-01-01
This study examined the validity of micro social observations and macro ratings of parent–child interaction in early to middle childhood. Seven hundred and thirty-one families representing multiple ethnic groups were recruited and screened as at risk in the context of Women, Infant, and Children (WIC) Nutritional Supplement service settings. Families were randomly assigned to the Family Checkup (FCU) intervention or the control condition at age 2 and videotaped in structured interactions in the home at ages 2, 3, 4, and 5. Parent–child interaction videotapes were microcoded using the Relationship Affect Coding System (RACS) that captures the duration of two mutual dyadic states: positive engagement and coercion. Macro ratings of parenting skills were collected after coding the videotapes to assess parent use of positive behavior support and limit setting skills (or lack thereof). Confirmatory factor analyses revealed that the measurement model of macro ratings of limit setting and positive behavior support was not supported by the data, and thus, were excluded from further analyses. However, there was moderate stability in the families’ micro social dynamics across early childhood and it showed significant improvements as a function of random assignment to the FCU. Moreover, parent–child dynamics were predictive of chronic behavior problems as rated by parents in middle childhood, but not emotional problems. We conclude with a discussion of the validity of the RACS and on methodological advantages of micro social coding over the statistical limitations of macro rating observations. Future directions are discussed for observation research in prevention science. PMID:27620623
Haedt-Matt, Alissa A; Keel, Pamela K
2011-07-01
The affect regulation model of binge eating, which posits that patients binge eat to reduce negative affect (NA), has received support from cross-sectional and laboratory-based studies. Ecological momentary assessment (EMA) involves momentary ratings and repeated assessments over time and is ideally suited to identify temporal antecedents and consequences of binge eating. This meta-analytic review includes EMA studies of affect and binge eating. Electronic database and manual searches produced 36 EMA studies with N = 968 participants (89% Caucasian women). Meta-analyses examined changes in affect before and after binge eating using within-subjects standardized mean gain effect sizes (ESs). Results supported greater NA preceding binge eating relative to average affect (ES = 0.63) and affect before regular eating (ES = 0.68). However, NA increased further following binge episodes (ES = 0.50). Preliminary findings suggested that NA decreased following purging in bulimia nervosa (ES = -0.46). Moderators included diagnosis (with significantly greater elevations of NA prior to bingeing in binge eating disorder compared to bulimia nervosa) and binge definition (with significantly smaller elevations of NA before binge vs. regular eating episodes for the Diagnostic and Statistical Manual of Mental Disorders definition compared to lay definitions of binge eating). Overall, results fail to support the affect regulation model of binge eating and challenge reductions in NA as a maintenance factor for binge eating. However, limitations of this literature include unidimensional analyses of NA and inadequate examination of affect during binge eating, as binge eating may regulate only specific facets of affect or may reduce NA only during the episode.
Dishion, Thomas J; Mun, Chung Jung; Tein, Jenn-Yun; Kim, Hanjoe; Shaw, Daniel S; Gardner, Frances; Wilson, Melvin N; Peterson, Jenene
2017-04-01
This study examined the validity of micro social observations and macro ratings of parent-child interaction in early to middle childhood. Seven hundred and thirty-one families representing multiple ethnic groups were recruited and screened as at risk in the context of Women, Infant, and Children (WIC) Nutritional Supplement service settings. Families were randomly assigned to the Family Checkup (FCU) intervention or the control condition at age 2 and videotaped in structured interactions in the home at ages 2, 3, 4, and 5. Parent-child interaction videotapes were micro-coded using the Relationship Affect Coding System (RACS) that captures the duration of two mutual dyadic states: positive engagement and coercion. Macro ratings of parenting skills were collected after coding the videotapes to assess parent use of positive behavior support and limit setting skills (or lack thereof). Confirmatory factor analyses revealed that the measurement model of macro ratings of limit setting and positive behavior support was not supported by the data, and thus, were excluded from further analyses. However, there was moderate stability in the families' micro social dynamics across early childhood and it showed significant improvements as a function of random assignment to the FCU. Moreover, parent-child dynamics were predictive of chronic behavior problems as rated by parents in middle childhood, but not emotional problems. We conclude with a discussion of the validity of the RACS and on methodological advantages of micro social coding over the statistical limitations of macro rating observations. Future directions are discussed for observation research in prevention science.
Lartillot, Nicolas; Brinkmann, Henner; Philippe, Hervé
2007-01-01
Background Thanks to the large amount of signal contained in genome-wide sequence alignments, phylogenomic analyses are converging towards highly supported trees. However, high statistical support does not imply that the tree is accurate. Systematic errors, such as the Long Branch Attraction (LBA) artefact, can be misleading, in particular when the taxon sampling is poor, or the outgroup is distant. In an otherwise consistent probabilistic framework, systematic errors in genome-wide analyses can be traced back to model mis-specification problems, which suggests that better models of sequence evolution should be devised, that would be more robust to tree reconstruction artefacts, even under the most challenging conditions. Methods We focus on a well characterized LBA artefact analyzed in a previous phylogenomic study of the metazoan tree, in which two fast-evolving animal phyla, nematodes and platyhelminths, emerge either at the base of all other Bilateria, or within protostomes, depending on the outgroup. We use this artefactual result as a case study for comparing the robustness of two alternative models: a standard, site-homogeneous model, based on an empirical matrix of amino-acid replacement (WAG), and a site-heterogeneous mixture model (CAT). In parallel, we propose a posterior predictive test, allowing one to measure how well a model acknowledges sequence saturation. Results Adopting a Bayesian framework, we show that the LBA artefact observed under WAG disappears when the site-heterogeneous model CAT is used. Using cross-validation, we further demonstrate that CAT has a better statistical fit than WAG on this data set. Finally, using our statistical goodness-of-fit test, we show that CAT, but not WAG, correctly accounts for the overall level of saturation, and that this is due to a better estimation of site-specific amino-acid preferences. Conclusion The CAT model appears to be more robust than WAG against LBA artefacts, essentially because it correctly anticipates the high probability of convergences and reversions implied by the small effective size of the amino-acid alphabet at each site of the alignment. More generally, our results provide strong evidence that site-specificities in the substitution process need be accounted for in order to obtain more reliable phylogenetic trees. PMID:17288577
Timol, Furzana; Vawda, Mohammed Yacoob; Bhana, Arvin; Moolman, Benita; Makoae, Mokhantso; Swartz, Sharlene
2016-01-01
Abstract Background: Peer-education programmes aim to bring about attitudinal and behavioural changes in their target audience. In the South African educational context, peer education is a favoured approach in dealing with issues such as HIV and AIDS, sexual decision-making and substance misuse. Given the reliance on peer-education programmes in the educational system, it is important to establish how well they are working. This study aims to assess the effect of an extensive, structured, time-limited, curriculum-based, peer-led educational programme on first-year high school learners in public schools in the Western Cape Province of South Africa. Method: The curriculum called ‘Listen Up’ addresses issues such as supporting peers, sexual decision-making, healthy relationships, HIV risk, alcohol misuse and unwanted pregnancy in seven structured sessions. The programme targeted adolescents in Grade 8 growing up in what are considered to be risky environments in public schools in the Western Cape during 2012 and 2013. The intervention was evaluated based on 10 scales sourced from published literature related to the outcome indicators of future orientation, sensation-seeking, self-efficacy in sexual relations, HIV transmission knowledge, HIV prevention knowledge, HIV attitudes, sexual attitudes, decision-making, healthy relationships and social support. Descriptive statistics were used to analyse demographic and community characteristics and analyses of variance were used to detect differences between groups. The surveys were administered to a total of 7709 learners across three waves of the study in 27 peer intervention schools and eight control schools. Results: Immediately post intervention, statistically significant differences were noted for the intervention schools when compared to their baseline levels on measures of future orientation, self-efficacy in sexual relations, knowledge regarding HIV transmission, knowledge regarding HIV prevention and knowledge in terms of healthy relationships. Comparing baseline values with results collected between five and seven months post intervention, statistically significant results were noted for self-efficacy in sexual relations and knowledge regarding HIV transmission. Conclusion: The findings of this study suggest that peer-education can improve adolescents’ self-efficacy in sexual relations as well as knowledge regarding the transmission of HIV and therefore can contribute to the prevention of HIV transmission among adolescents. PMID:27892820
Timol, Furzana; Vawda, Mohammed Yacoob; Bhana, Arvin; Moolman, Benita; Makoae, Mokhantso; Swartz, Sharlene
2016-12-01
Peer-education programmes aim to bring about attitudinal and behavioural changes in their target audience. In the South African educational context, peer education is a favoured approach in dealing with issues such as HIV and AIDS, sexual decision-making and substance misuse. Given the reliance on peer-education programmes in the educational system, it is important to establish how well they are working. This study aims to assess the effect of an extensive, structured, time-limited, curriculum-based, peer-led educational programme on first-year high school learners in public schools in the Western Cape Province of South Africa. The curriculum called 'Listen Up' addresses issues such as supporting peers, sexual decision-making, healthy relationships, HIV risk, alcohol misuse and unwanted pregnancy in seven structured sessions. The programme targeted adolescents in Grade 8 growing up in what are considered to be risky environments in public schools in the Western Cape during 2012 and 2013. The intervention was evaluated based on 10 scales sourced from published literature related to the outcome indicators of future orientation, sensation-seeking, self-efficacy in sexual relations, HIV transmission knowledge, HIV prevention knowledge, HIV attitudes, sexual attitudes, decision-making, healthy relationships and social support. Descriptive statistics were used to analyse demographic and community characteristics and analyses of variance were used to detect differences between groups. The surveys were administered to a total of 7709 learners across three waves of the study in 27 peer intervention schools and eight control schools. Immediately post intervention, statistically significant differences were noted for the intervention schools when compared to their baseline levels on measures of future orientation, self-efficacy in sexual relations, knowledge regarding HIV transmission, knowledge regarding HIV prevention and knowledge in terms of healthy relationships. Comparing baseline values with results collected between five and seven months post intervention, statistically significant results were noted for self-efficacy in sexual relations and knowledge regarding HIV transmission. The findings of this study suggest that peer-education can improve adolescents' self-efficacy in sexual relations as well as knowledge regarding the transmission of HIV and therefore can contribute to the prevention of HIV transmission among adolescents.
Castro, Marcelo P; Pataky, Todd C; Sole, Gisela; Vilas-Boas, Joao Paulo
2015-07-16
Ground reaction force (GRF) data from men and women are commonly pooled for analyses. However, it may not be justifiable to pool sexes on the basis of discrete parameters extracted from continuous GRF gait waveforms because this can miss continuous effects. Forty healthy participants (20 men and 20 women) walked at a cadence of 100 steps per minute across two force plates, recording GRFs. Two statistical methods were used to test the null hypothesis of no mean GRF differences between sexes: (i) Statistical Parametric Mapping-using the entire three-component GRF waveform; and (ii) traditional approach-using the first and second vertical GRF peaks. Statistical Parametric Mapping results suggested large sex differences, which post-hoc analyses suggested were due predominantly to higher anterior-posterior and vertical GRFs in early stance in women compared to men. Statistically significant differences were observed for the first GRF peak and similar values for the second GRF peak. These contrasting results emphasise that different parts of the waveform have different signal strengths and thus that one may use the traditional approach to choose arbitrary metrics and make arbitrary conclusions. We suggest that researchers and clinicians consider both the entire gait waveforms and sex-specificity when analysing GRF data. Copyright © 2015 Elsevier Ltd. All rights reserved.
ERIC Educational Resources Information Center
Merrill, Ray M.; Chatterley, Amanda; Shields, Eric C.
2005-01-01
This study explored the effectiveness of selected statistical measures at motivating or maintaining regular exercise among college students. The study also considered whether ease in understanding these statistical measures was associated with perceived effectiveness at motivating or maintaining regular exercise. Analyses were based on a…
ERIC Educational Resources Information Center
Petocz, Peter; Sowey, Eric
2012-01-01
The term "data snooping" refers to the practice of choosing which statistical analyses to apply to a set of data after having first looked at those data. Data snooping contradicts a fundamental precept of applied statistics, that the scheme of analysis is to be planned in advance. In this column, the authors shall elucidate the…
The Empirical Nature and Statistical Treatment of Missing Data
ERIC Educational Resources Information Center
Tannenbaum, Christyn E.
2009-01-01
Introduction. Missing data is a common problem in research and can produce severely misleading analyses, including biased estimates of statistical parameters, and erroneous conclusions. In its 1999 report, the APA Task Force on Statistical Inference encouraged authors to report complications such as missing data and discouraged the use of…
ERIC Educational Resources Information Center
Norris, John M.
2015-01-01
Traditions of statistical significance testing in second language (L2) quantitative research are strongly entrenched in how researchers design studies, select analyses, and interpret results. However, statistical significance tests using "p" values are commonly misinterpreted by researchers, reviewers, readers, and others, leading to…
Federal Register 2010, 2011, 2012, 2013, 2014
2010-05-05
...] Guidance for Industry on Documenting Statistical Analysis Programs and Data Files; Availability AGENCY... Programs and Data Files.'' This guidance is provided to inform study statisticians of recommendations for documenting statistical analyses and data files submitted to the Center for Veterinary Medicine (CVM) for the...
Development of the Statistical Reasoning in Biology Concept Inventory (SRBCI).
Deane, Thomas; Nomme, Kathy; Jeffery, Erica; Pollock, Carol; Birol, Gülnur
2016-01-01
We followed established best practices in concept inventory design and developed a 12-item inventory to assess student ability in statistical reasoning in biology (Statistical Reasoning in Biology Concept Inventory [SRBCI]). It is important to assess student thinking in this conceptual area, because it is a fundamental requirement of being statistically literate and associated skills are needed in almost all walks of life. Despite this, previous work shows that non-expert-like thinking in statistical reasoning is common, even after instruction. As science educators, our goal should be to move students along a novice-to-expert spectrum, which could be achieved with growing experience in statistical reasoning. We used item response theory analyses (the one-parameter Rasch model and associated analyses) to assess responses gathered from biology students in two populations at a large research university in Canada in order to test SRBCI's robustness and sensitivity in capturing useful data relating to the students' conceptual ability in statistical reasoning. Our analyses indicated that SRBCI is a unidimensional construct, with items that vary widely in difficulty and provide useful information about such student ability. SRBCI should be useful as a diagnostic tool in a variety of biology settings and as a means of measuring the success of teaching interventions designed to improve statistical reasoning skills. © 2016 T. Deane et al. CBE—Life Sciences Education © 2016 The American Society for Cell Biology. This article is distributed by The American Society for Cell Biology under license from the author(s). It is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).
Banerjee, S; Califano, R; Corral, J; de Azambuja, E; De Mattos-Arruda, L; Guarneri, V; Hutka, M; Jordan, K; Martinelli, E; Mountzios, G; Ozturk, M A; Petrova, M; Postel-Vinay, S; Preusser, M; Qvortrup, C; Volkov, M N M; Tabernero, J; Olmos, D; Strijbos, M H
2017-07-01
Burnout in health care professionals could have serious negative consequences on quality of patient care, professional satisfaction and personal life. Our aim was to investigate the burnout prevalence, work and lifestyle factors potentially affecting burnout amongst European oncologists ≤40 (YOs). A survey was conducted using the validated Maslach Burnout Inventory (MBI) and additional questions exploring work/lifestyle factors. Statistical analyses were carried out to identify factors associated with burnout. Total of 737 surveys (all ages) were collected from 41 European countries. Countries were divided into six regions. Results from 595 (81%) YOs were included (81% medical oncologists; 52% trainees, 62% women). Seventy-one percent of YOs showed evidence of burnout (burnout subdomains: depersonalization 50%; emotional exhaustion 45; low accomplishment 35%). Twenty-two percent requested support for burnout during training and 74% reported no hospital access to support services. Burnout rates were significantly different across Europe (P < 0.0001). Burnout was highest in central European (84%) and lowest in Northern Europe (52%). Depersonalization scores were higher in men compared with women (60% versus 45% P = 0.0001) and low accomplishment was highest in the 26-30 age group (P < 0.01). In multivariable linear regression analyses, European region, work/life balance, access to support services, living alone and inadequate vacation time remained independent burnout factors (P < 0.05). This is the largest burnout survey in European Young Oncologists. Burnout is common amongst YOs and rates vary across Europe. Achieving a good work/life balance, access to support services and adequate vacation time may reduce burnout levels. Raising awareness, support and interventional research are needed. © The Author 2017. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.