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.
Duration on unemployment: geographic mobility and selectivity bias.
Goss, E P; Paul, C; Wilhite, A
1994-01-01
Modeling the factors affecting the duration of unemployment was found to be influenced by the inclusion of migration factors. Traditional models which did not control for migration factors were found to underestimate movers' probability of finding an acceptable job. The empirical test of the theory, based on the analysis of data on US household heads unemployed in 1982 and employed in 1982 and 1983, found that the cumulative probability of reemployment in the traditional model was .422 and in the migration selectivity model was .624 after 30 weeks of searching. In addition, controlling for selectivity eliminated the significance of the relationship between race and job search duration in the model. The relationship between search duration and the county unemployment rate in 1982 became statistically significant, and the relationship between search duration and 1980 population per square mile in the 1982 county of residence became statistically insignificant. The finding that non-Whites have a longer duration of unemployment can better be understood as non-Whites' lower geographic mobility and lack of greater job contacts. The statistical significance of a high unemployment rate in the home labor market reducing the probability of finding employment was more in keeping with expectations. The findings assumed that the duration of employment accurately reflected the length of job search. The sample was redrawn to exclude discouraged workers and the analysis was repeated. The findings were similar to the full sample, with the coefficient for migration variable being negative and statistically significant and the coefficient for alpha remaining positive and statistically significant. Race in the selectivity model remained statistically insignificant. The findings supported the Schwartz model hypothesizing that the expansion of the radius of the search would reduce the duration of unemployment. The exclusion of the migration factor misspecified the equation for unemployment duration. Policy should be directed to the problems of geographic mobility, particularly among non-Whites.
O'Keefe, Daniel J; Jensen, Jakob D
2007-01-01
A meta-analytic review of 93 studies (N = 21,656) finds that in disease prevention messages, gain-framed appeals, which emphasize the advantages of compliance with the communicator's recommendation, are statistically significantly more persuasive than loss-framed appeals, which emphasize the disadvantages of noncompliance. This difference is quite small (corresponding to r = .03), however, and appears attributable to a relatively large (and statistically significant) effect for messages advocating dental hygiene behaviors. Despite very good statistical power, the analysis finds no statistically significant differences in persuasiveness between gain- and loss-framed messages concerning other preventive actions such as safer-sex behaviors, skin cancer prevention behaviors, or diet and nutrition behaviors.
Bowllan, Nancy M
2011-04-01
This intervention study examined the prevalence of bullying in an urban/suburban middle school and the impact of the Olweus Bullying Prevention Program (OBPP). A quasi-experimental design consisting of a time-lagged contrast between age-equivalent groups was utilized. Baseline data collected for 158 students prior to implementation of the OBPP were compared to 112 students who received the OBPP intervention for 1 year. Multiple perspectives on bullying were collected using the Revised-Olweus Bully/Victim Questionnaire. Similarly, a teacher questionnaire collected data for 17 teachers on prevalence of bullying and capacity to intervene pre- and post- OBPP intervention. Descriptive and inferential statistics were generated to analyze findings. Statistically significant findings were found for 7th grade female students who received 1 year of the OBPP on reports of prevalence of bullying (p = .022) and exclusion by peers (p = .009). In contrast, variability in statistical findings was obtained for 8th grade females and no statistical findings were found for males. Following 1 year of the OBPP, teachers reported statistically significant improvements in their capacity to identify bullying (p = .016), talk to students who bully (p = .024), and talk with students who are bullied (p = .051). Other substantial percentile changes were also noted. Findings suggest a significant positive impact of the OBPP on 7th grade females and teachers. Other grade and gender findings were inconsistent with previous literature. Recommendations for further research are provided along with implications for school health prevention programming. © 2011, American School Health Association.
Comparison between the Laser-Badal and Vernier Optometers.
1988-09-01
naval aviators (SNAs). We also measured dark vcrgence in the same sample of SNAs. THE FINDINGS There was no statistically significant difference found...relatively inexperienced operator. 7. The difference between mean scores on the vernier and laser-Badal optometers was statistically significant...thus indicating that test results were reliable within instru- menrts. TAbLE 1. Test and Retest Statistics . Measure Mean SD n t-value Dark vergence
Harari, Gil
2014-01-01
Statistic significance, also known as p-value, and CI (Confidence Interval) are common statistics measures and are essential for the statistical analysis of studies in medicine and life sciences. These measures provide complementary information about the statistical probability and conclusions regarding the clinical significance of study findings. This article is intended to describe the methodologies, compare between the methods, assert their suitability for the different needs of study results analysis and to explain situations in which each method should be used.
Phenformin-induced Hypoglycaemia in Normal Subjects*
Lyngsøe, J.; Trap-Jensen, J.
1969-01-01
Study of the effect of phenformin on the blood glucose level in normal subjects before and during 70 hours of starvation showed a statistically significant hypoglycaemic effect after 40 hours of starvation. This effect was not due to increased glucose utilization. Another finding in this study was a statistically significant decrease in total urinary nitrogen excretion during starvation in subjects given phenformin. These findings show that the hypoglycaemic effect of phenformin in starved normal subjects is due to inhibition of gluconeogenesis. PMID:5780431
Potential errors and misuse of statistics in studies on leakage in endodontics.
Lucena, C; Lopez, J M; Pulgar, R; Abalos, C; Valderrama, M J
2013-04-01
To assess the quality of the statistical methodology used in studies of leakage in Endodontics, and to compare the results found using appropriate versus inappropriate inferential statistical methods. The search strategy used the descriptors 'root filling' 'microleakage', 'dye penetration', 'dye leakage', 'polymicrobial leakage' and 'fluid filtration' for the time interval 2001-2010 in journals within the categories 'Dentistry, Oral Surgery and Medicine' and 'Materials Science, Biomaterials' of the Journal Citation Report. All retrieved articles were reviewed to find potential pitfalls in statistical methodology that may be encountered during study design, data management or data analysis. The database included 209 papers. In all the studies reviewed, the statistical methods used were appropriate for the category attributed to the outcome variable, but in 41% of the cases, the chi-square test or parametric methods were inappropriately selected subsequently. In 2% of the papers, no statistical test was used. In 99% of cases, a statistically 'significant' or 'not significant' effect was reported as a main finding, whilst only 1% also presented an estimation of the magnitude of the effect. When the appropriate statistical methods were applied in the studies with originally inappropriate data analysis, the conclusions changed in 19% of the cases. Statistical deficiencies in leakage studies may affect their results and interpretation and might be one of the reasons for the poor agreement amongst the reported findings. Therefore, more effort should be made to standardize statistical methodology. © 2012 International Endodontic Journal.
Baek, Hye Jin; Lee, Jeong Hyun; Lim, Hyun Kyung; Lee, Ha Young; Baek, Jung Hwan
2014-11-01
To determine the optimal clinical and CT findings for differentiating Kikuchi's disease (KD) and tuberculous lymphadenitis (TB) in patients presenting with cervical lymphadenopathy. From 2006 to 2010, 87 consecutive patients who were finally diagnosed with KD or TB were enrolled. Two radiologists performed independent analysis of contrast-enhanced neck CT images with regard to the involvement pattern, nodal or perinodal changes, and evidence of the previous infection. Significant clinical and CT findings of KD were determined by statistical analyses. Of the 87 patients, 27 (31%) were classified as having KD and 60 (69%) as having TB. Statistically significant findings of KD patients were younger age, presence of fever, involvement of ≥5 nodal levels or the bilateral neck, no or minimal nodal necrosis, marked perinodal infiltration, and no evidence of upper lung lesion or mediastinal lymphadenopathy. The presence of four or more statistically significant clinical and CT findings of KD had the largest area under the receiver-operating characteristic curve (A z = 0.861; 95% confidence intervals 0.801, 0.909), with a sensitivity of 89% and specificity of 83%. CT can be a helpful tool for differentiating KD from TB, especially when it is combined with the clinical findings.
ERIC Educational Resources Information Center
Hartsoe, Joseph K.; Barclay, Susan R.
2017-01-01
The purpose of this study was to investigate faculty belief, knowledge, and confidence in the principles of Universal Design for Instruction (UDI). Results yielded statistically significant correlations between participant's belief and knowledge of the principles of UDI. Furthermore, findings yielded statistically significant differences between…
Orbital Roof Fractures as an Indicator for Concomitant Ocular Injury
2017-11-12
between these two groups to indicate a statistically significant difference in mechanism of injury, subjective symptoms, CT and exam findings, and...using Pearson’s x2 test or Fisher’s exact test to indicate a statistically significant difference in mechanism of injury, subjective symptoms, CT and
Benchmarking can add up for healthcare accounting.
Czarnecki, M T
1994-09-01
In 1993, a healthcare accounting and finance benchmarking survey of hospital and nonhospital organizations gathered statistics about key common performance areas. A low response did not allow for statistically significant findings, but the survey identified performance measures that can be used in healthcare financial management settings. This article explains the benchmarking process and examines some of the 1993 study's findings.
Chest CT findings of toxocariasis: correlation with laboratory results.
Hur, J H; Lee, I J; Kim, J-H; Kim, D-G; Hwang, H J; Koh, S H; Lee, K
2014-06-01
To assess the relationship between chest computed tomography (CT) findings of patients with toxocariasis and levels of serological markers. A total of 38 cases of patients diagnosed with toxocariasis by enzyme-linked immunosorbent assay (ELISA), CT, and serological markers were retrospectively reviewed. The presence of nodule with or without ground-glass opacity (GGO) halo, consolidation, focal GGO, pleural effusion, and lymphadenopathy at chest CT were evaluated. Statistical analysis was performed with the Fisher's exact test. The most common chest CT findings were nodule (n = 12, 31.6%) and focal GGO (n = 12, 31.6%). In patients with normal eosinophil levels, focal GGO (n = 9, 37.5%) was the most common finding. In contrast, nodule with a GGO halo (n = 7, 50%) was the most common finding in the eosinophilia group. Nodule with a GGO halo was more common in the eosinophilia group, with a statistically significant difference (p = 0.017). Nodule was more common in the eosinophilia group, and focal GGO was more common in the normal eosinophil group. The most common chest CT findings in toxocariasis were nodule with or without GGO halo, and focal GGO. In the eosinophilia group, nodule with a GGO halo was significantly more frequent. Other CT findings did not show a statistically significant relationship with serological markers. Copyright © 2014 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.
Significant Statistics: Viewed with a Contextual Lens
ERIC Educational Resources Information Center
Tait-McCutcheon, Sandi
2010-01-01
This paper examines the pedagogical and organisational changes three lead teachers made to their statistics teaching and learning programs. The lead teachers posed the research question: What would the effect of contextually integrating statistical investigations and literacies into other curriculum areas be on student achievement? By finding the…
Evidential Value That Exercise Improves BMI z-Score in Overweight and Obese Children and Adolescents
Kelley, George A.; Kelley, Kristi S.
2015-01-01
Background. Given the cardiovascular disease (CVD) related importance of understanding the true effects of exercise on adiposity in overweight and obese children and adolescents, this study examined whether there is evidential value to rule out excessive and inappropriate reporting of statistically significant results, a major problem in the published literature, with respect to exercise-induced improvements in BMI z-score among overweight and obese children and adolescents. Methods. Using data from a previous meta-analysis of 10 published studies that included 835 overweight and obese children and adolescents, a novel, recently developed approach (p-curve) was used to test for evidential value and rule out selective reporting of findings. Chi-squared tests (χ 2) were used to test for statistical significance with alpha (p) values <0.05 considered statistically significant. Results. Six of 10 findings (60%) were statistically significant. Statistically significant right-skew to rule out selective reporting was found (χ 2 = 38.8, p = 0.0001). Conversely, studies neither lacked evidential value (χ 2 = 6.8, p = 0.87) nor lacked evidential value and were intensely p-hacked (χ 2 = 4.3, p = 0.98). Conclusion. Evidential value results confirm that exercise reduces BMI z-score in overweight and obese children and adolescents, an important therapeutic strategy for treating and preventing CVD. PMID:26509145
Kelley, George A; Kelley, Kristi S
2015-01-01
Background. Given the cardiovascular disease (CVD) related importance of understanding the true effects of exercise on adiposity in overweight and obese children and adolescents, this study examined whether there is evidential value to rule out excessive and inappropriate reporting of statistically significant results, a major problem in the published literature, with respect to exercise-induced improvements in BMI z-score among overweight and obese children and adolescents. Methods. Using data from a previous meta-analysis of 10 published studies that included 835 overweight and obese children and adolescents, a novel, recently developed approach (p-curve) was used to test for evidential value and rule out selective reporting of findings. Chi-squared tests (χ (2)) were used to test for statistical significance with alpha (p) values <0.05 considered statistically significant. Results. Six of 10 findings (60%) were statistically significant. Statistically significant right-skew to rule out selective reporting was found (χ (2) = 38.8, p = 0.0001). Conversely, studies neither lacked evidential value (χ (2) = 6.8, p = 0.87) nor lacked evidential value and were intensely p-hacked (χ (2) = 4.3, p = 0.98). Conclusion. Evidential value results confirm that exercise reduces BMI z-score in overweight and obese children and adolescents, an important therapeutic strategy for treating and preventing CVD.
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.
Areepattamannil, Shaljan
2014-01-01
This study examined the relationships between academic motivation-intrinsic motivation, extrinsic motivation, amotivation-and mathematics achievement among 363 Indian adolescents in India and 355 Indian immigrant adolescents in Canada. Results of hierarchical multiple regression analyses showed that intrinsic motivation, extrinsic motivation, and amotivation were not statistically significantly related to mathematics achievement among Indian adolescents in India. In contrast, both intrinsic motivation and extrinsic motivation were statistically significantly related to mathematics achievement among Indian immigrant adolescents in Canada. While intrinsic motivation was a statistically significant positive predictor of mathematics achievement among Indian immigrant adolescents in Canada, extrinsic motivation was a statistically significant negative predictor of mathematics achievement among Indian immigrant adolescents in Canada. Amotivation was not statistically significantly related to mathematics achievement among Indian immigrant adolescents in Canada. Implications of the findings for pedagogy and practice are discussed.
Gender Differences in Public Relations Students' Career Attitudes: A Benchmark Study.
ERIC Educational Resources Information Center
Farmer, Betty; Waugh, Lisa
1999-01-01
Explores students' perceptions of gender issues in public relations. Finds that there were no statistically significant differences in male and female students' desires to perform managerial activities, but there were statistically significant differences in several areas (i.e. female students expect to earn less money starting out and to be…
Shrout, Patrick E; Rodgers, Joseph L
2018-01-04
Psychology advances knowledge by testing statistical hypotheses using empirical observations and data. The expectation is that most statistically significant findings can be replicated in new data and in new laboratories, but in practice many findings have replicated less often than expected, leading to claims of a replication crisis. We review recent methodological literature on questionable research practices, meta-analysis, and power analysis to explain the apparently high rates of failure to replicate. Psychologists can improve research practices to advance knowledge in ways that improve replicability. We recommend that researchers adopt open science conventions of preregi-stration and full disclosure and that replication efforts be based on multiple studies rather than on a single replication attempt. We call for more sophisticated power analyses, careful consideration of the various influences on effect sizes, and more complete disclosure of nonsignificant as well as statistically significant findings.
Power-up: A Reanalysis of 'Power Failure' in Neuroscience Using Mixture Modeling
Wood, John
2017-01-01
Recently, evidence for endemically low statistical power has cast neuroscience findings into doubt. If low statistical power plagues neuroscience, then this reduces confidence in the reported effects. However, if statistical power is not uniformly low, then such blanket mistrust might not be warranted. Here, we provide a different perspective on this issue, analyzing data from an influential study reporting a median power of 21% across 49 meta-analyses (Button et al., 2013). We demonstrate, using Gaussian mixture modeling, that the sample of 730 studies included in that analysis comprises several subcomponents so the use of a single summary statistic is insufficient to characterize the nature of the distribution. We find that statistical power is extremely low for studies included in meta-analyses that reported a null result and that it varies substantially across subfields of neuroscience, with particularly low power in candidate gene association studies. Therefore, whereas power in neuroscience remains a critical issue, the notion that studies are systematically underpowered is not the full story: low power is far from a universal problem. SIGNIFICANCE STATEMENT Recently, researchers across the biomedical and psychological sciences have become concerned with the reliability of results. One marker for reliability is statistical power: the probability of finding a statistically significant result given that the effect exists. Previous evidence suggests that statistical power is low across the field of neuroscience. Our results present a more comprehensive picture of statistical power in neuroscience: on average, studies are indeed underpowered—some very seriously so—but many studies show acceptable or even exemplary statistical power. We show that this heterogeneity in statistical power is common across most subfields in neuroscience. This new, more nuanced picture of statistical power in neuroscience could affect not only scientific understanding, but potentially policy and funding decisions for neuroscience research. PMID:28706080
Alignments of parity even/odd-only multipoles in CMB
NASA Astrophysics Data System (ADS)
Aluri, Pavan K.; Ralston, John P.; Weltman, Amanda
2017-12-01
We compare the statistics of parity even and odd multipoles of the cosmic microwave background (CMB) sky from Planck full mission temperature measurements. An excess power in odd multipoles compared to even multipoles has previously been found on large angular scales. Motivated by this apparent parity asymmetry, we evaluate directional statistics associated with even compared to odd multipoles, along with their significances. Primary tools are the Power tensor and Alignment tensor statistics. We limit our analysis to the first 60 multipoles i.e. l = [2, 61]. We find no evidence for statistically unusual alignments of even parity multipoles. More than one independent statistic finds evidence for alignments of anisotropy axes of odd multipoles, with a significance equivalent to ∼2σ or more. The robustness of alignment axes is tested by making Galactic cuts and varying the multipole range. Very interestingly, the region spanned by the (a)symmetry axes is found to broadly contain other parity (a)symmetry axes previously observed in the literature.
Wicherts, Jelte M.; Bakker, Marjan; Molenaar, Dylan
2011-01-01
Background The widespread reluctance to share published research data is often hypothesized to be due to the authors' fear that reanalysis may expose errors in their work or may produce conclusions that contradict their own. However, these hypotheses have not previously been studied systematically. Methods and Findings We related the reluctance to share research data for reanalysis to 1148 statistically significant results reported in 49 papers published in two major psychology journals. We found the reluctance to share data to be associated with weaker evidence (against the null hypothesis of no effect) and a higher prevalence of apparent errors in the reporting of statistical results. The unwillingness to share data was particularly clear when reporting errors had a bearing on statistical significance. Conclusions Our findings on the basis of psychological papers suggest that statistical results are particularly hard to verify when reanalysis is more likely to lead to contrasting conclusions. This highlights the importance of establishing mandatory data archiving policies. PMID:22073203
A statistical approach to selecting and confirming validation targets in -omics experiments
2012-01-01
Background Genomic technologies are, by their very nature, designed for hypothesis generation. In some cases, the hypotheses that are generated require that genome scientists confirm findings about specific genes or proteins. But one major advantage of high-throughput technology is that global genetic, genomic, transcriptomic, and proteomic behaviors can be observed. Manual confirmation of every statistically significant genomic result is prohibitively expensive. This has led researchers in genomics to adopt the strategy of confirming only a handful of the most statistically significant results, a small subset chosen for biological interest, or a small random subset. But there is no standard approach for selecting and quantitatively evaluating validation targets. Results Here we present a new statistical method and approach for statistically validating lists of significant results based on confirming only a small random sample. We apply our statistical method to show that the usual practice of confirming only the most statistically significant results does not statistically validate result lists. We analyze an extensively validated RNA-sequencing experiment to show that confirming a random subset can statistically validate entire lists of significant results. Finally, we analyze multiple publicly available microarray experiments to show that statistically validating random samples can both (i) provide evidence to confirm long gene lists and (ii) save thousands of dollars and hundreds of hours of labor over manual validation of each significant result. Conclusions For high-throughput -omics studies, statistical validation is a cost-effective and statistically valid approach to confirming lists of significant results. PMID:22738145
A Hybrid Template-Based Composite Classification System
2009-02-01
Hybrid Classifier: Forced Decision . . . . 116 5.3.2 Forced Decision Experimental Results . . . . . 119 5.3.3 Test for Statistical Significance ...Results . . . . . . . . . . 127 5.4.2 Test for Statistical Significance : NDEC Option 129 5.5 Implementing the Hyrid Classifier with OOL Targets . 130...comple- mentary in nature . Complementary classifiers are observed by finding an optimal method for partitioning the problem space. For example, the
ERIC Educational Resources Information Center
Williams, Amanda S.
2015-01-01
Statistics anxiety is a common problem for graduate students. This study explores the multivariate relationship between a set of worry-related variables and six types of statistics anxiety. Canonical correlation analysis indicates a significant relationship between the two sets of variables. Findings suggest that students who are more intolerant…
CAVALCANTI, Andrea Nóbrega; MARCHI, Giselle Maria; AMBROSANO, Gláucia Maria Bovi
2010-01-01
Statistical analysis interpretation is a critical field in scientific research. When there is more than one main variable being studied in a research, the effect of the interaction between those variables is fundamental on experiments discussion. However, some doubts can occur when the p-value of the interaction is greater than the significance level. Objective To determine the most adequate interpretation for factorial experiments with p-values of the interaction nearly higher than the significance level. Materials and methods The p-values of the interactions found in two restorative dentistry experiments (0.053 and 0.068) were interpreted in two distinct ways: considering the interaction as not significant and as significant. Results Different findings were observed between the two analyses, and studies results became more coherent when the significant interaction was used. Conclusion The p-value of the interaction between main variables must be analyzed with caution because it can change the outcomes of research studies. Researchers are strongly advised to interpret carefully the results of their statistical analysis in order to discuss the findings of their experiments properly. PMID:20857003
Power-up: A Reanalysis of 'Power Failure' in Neuroscience Using Mixture Modeling.
Nord, Camilla L; Valton, Vincent; Wood, John; Roiser, Jonathan P
2017-08-23
Recently, evidence for endemically low statistical power has cast neuroscience findings into doubt. If low statistical power plagues neuroscience, then this reduces confidence in the reported effects. However, if statistical power is not uniformly low, then such blanket mistrust might not be warranted. Here, we provide a different perspective on this issue, analyzing data from an influential study reporting a median power of 21% across 49 meta-analyses (Button et al., 2013). We demonstrate, using Gaussian mixture modeling, that the sample of 730 studies included in that analysis comprises several subcomponents so the use of a single summary statistic is insufficient to characterize the nature of the distribution. We find that statistical power is extremely low for studies included in meta-analyses that reported a null result and that it varies substantially across subfields of neuroscience, with particularly low power in candidate gene association studies. Therefore, whereas power in neuroscience remains a critical issue, the notion that studies are systematically underpowered is not the full story: low power is far from a universal problem. SIGNIFICANCE STATEMENT Recently, researchers across the biomedical and psychological sciences have become concerned with the reliability of results. One marker for reliability is statistical power: the probability of finding a statistically significant result given that the effect exists. Previous evidence suggests that statistical power is low across the field of neuroscience. Our results present a more comprehensive picture of statistical power in neuroscience: on average, studies are indeed underpowered-some very seriously so-but many studies show acceptable or even exemplary statistical power. We show that this heterogeneity in statistical power is common across most subfields in neuroscience. This new, more nuanced picture of statistical power in neuroscience could affect not only scientific understanding, but potentially policy and funding decisions for neuroscience research. Copyright © 2017 Nord, Valton et al.
Emergence of patterns in random processes
NASA Astrophysics Data System (ADS)
Newman, William I.; Turcotte, Donald L.; Malamud, Bruce D.
2012-08-01
Sixty years ago, it was observed that any independent and identically distributed (i.i.d.) random variable would produce a pattern of peak-to-peak sequences with, on average, three events per sequence. This outcome was employed to show that randomness could yield, as a null hypothesis for animal populations, an explanation for their apparent 3-year cycles. We show how we can explicitly obtain a universal distribution of the lengths of peak-to-peak sequences in time series and that this can be employed for long data sets as a test of their i.i.d. character. We illustrate the validity of our analysis utilizing the peak-to-peak statistics of a Gaussian white noise. We also consider the nearest-neighbor cluster statistics of point processes in time. If the time intervals are random, we show that cluster size statistics are identical to the peak-to-peak sequence statistics of time series. In order to study the influence of correlations in a time series, we determine the peak-to-peak sequence statistics for the Langevin equation of kinetic theory leading to Brownian motion. To test our methodology, we consider a variety of applications. Using a global catalog of earthquakes, we obtain the peak-to-peak statistics of earthquake magnitudes and the nearest neighbor interoccurrence time statistics. In both cases, we find good agreement with the i.i.d. theory. We also consider the interval statistics of the Old Faithful geyser in Yellowstone National Park. In this case, we find a significant deviation from the i.i.d. theory which we attribute to antipersistence. We consider the interval statistics using the AL index of geomagnetic substorms. We again find a significant deviation from i.i.d. behavior that we attribute to mild persistence. Finally, we examine the behavior of Standard and Poor's 500 stock index's daily returns from 1928-2011 and show that, while it is close to being i.i.d., there is, again, significant persistence. We expect that there will be many other applications of our methodology both to interoccurrence statistics and to time series.
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.
Banff study of pathologic changes in lung allograft biopsy specimens with donor-specific antibodies.
Wallace, William Dean; Li, Ning; Andersen, Claus B; Arrossi, A Valeria; Askar, Medhat; Berry, Gerry J; DeNicola, Matthew M; Neil, Desley A; Pavlisko, Elizabeth N; Reed, Elaine F; Remmelink, Myriam; Weigt, S Sam; Weynand, Birgit; Zhang, Jennifer Q; Budev, Marie M; Farver, Carol F
2016-01-01
The diagnosis of antibody-mediated rejection (AMR) in the lung transplant is still an area under investigation. We performed a blinded multicenter study to determine if any statistically significant histologic findings in transbronchial biopsy specimens from lung transplant patients correlate with the presence of donor-specific antibodies (DSAs). We asked 9 pathologists with experience in lung transplantation to evaluate 161 lung transplant biopsy specimens for various histologic parameters. The findings were correlated with antibody status positive for DSAs, positive for non-DSAs, and no antibodies (NABs) present. The significance of each histologic variable was reviewed. We found no statistically significant association with acute cellular rejection, airway inflammation, or bronchiolitis obliterans and the presence or absence of antibodies. However, biopsy specimens with DSAs had a statistically significant difference vs NABs in the setting of acute lung injury, with or without diffuse alveolar damage (p = 0.0008), in the presence of capillary neutrophilic inflammation (p = 0.0014), and in samples with endotheliitis (p = 0.0155). In samples with complement 4d staining, there was a trend but no statistically significant difference between specimens associated with DSAs and specimens with NABs. Capillary inflammation, acute lung injury, and endotheliitis significantly correlated with DSAs. The infrequently observed diffuse staining for complement 4d limits the usefulness of this stain. Copyright © 2016 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.
Superposed epoch analysis of physiological fluctuations: possible space weather connections
NASA Astrophysics Data System (ADS)
Wanliss, James; Cornélissen, Germaine; Halberg, Franz; Brown, Denzel; Washington, Brien
2018-03-01
There is a strong connection between space weather and fluctuations in technological systems. Some studies also suggest a statistical connection between space weather and subsequent fluctuations in the physiology of living creatures. This connection, however, has remained controversial and difficult to demonstrate. Here we present support for a response of human physiology to forcing from the explosive onset of the largest of space weather events—space storms. We consider a case study with over 16 years of high temporal resolution measurements of human blood pressure (systolic, diastolic) and heart rate variability to search for associations with space weather. We find no statistically significant change in human blood pressure but a statistically significant drop in heart rate during the main phase of space storms. Our empirical findings shed light on how human physiology may respond to exogenous space weather forcing.
Superposed epoch analysis of physiological fluctuations: possible space weather connections.
Wanliss, James; Cornélissen, Germaine; Halberg, Franz; Brown, Denzel; Washington, Brien
2018-03-01
There is a strong connection between space weather and fluctuations in technological systems. Some studies also suggest a statistical connection between space weather and subsequent fluctuations in the physiology of living creatures. This connection, however, has remained controversial and difficult to demonstrate. Here we present support for a response of human physiology to forcing from the explosive onset of the largest of space weather events-space storms. We consider a case study with over 16 years of high temporal resolution measurements of human blood pressure (systolic, diastolic) and heart rate variability to search for associations with space weather. We find no statistically significant change in human blood pressure but a statistically significant drop in heart rate during the main phase of space storms. Our empirical findings shed light on how human physiology may respond to exogenous space weather forcing.
Quasi-Monochromatic Visual Environments and the Resting Point of Accommodation
1988-01-01
accommodation. No statistically significant differences were revealed to support the possibility of color mediated differential regression to resting...discussed with respect to the general findings of the total sample as well as the specific behavior of individual participants. The summarized statistics ...remaining ten varied considerably with respect to the averaged trends reported in the above descriptive statistics as well as with respect to precision
Vahedi, Shahrum; Farrokhi, Farahman; Gahramani, Farahnaz; Issazadegan, Ali
2012-01-01
Approximately 66-80%of graduate students experience statistics anxiety and some researchers propose that many students identify statistics courses as the most anxiety-inducing courses in their academic curriculums. As such, it is likely that statistics anxiety is, in part, responsible for many students delaying enrollment in these courses for as long as possible. This paper proposes a canonical model by treating academic procrastination (AP), learning strategies (LS) as predictor variables and statistics anxiety (SA) as explained variables. A questionnaire survey was used for data collection and 246-college female student participated in this study. To examine the mutually independent relations between procrastination, learning strategies and statistics anxiety variables, a canonical correlation analysis was computed. Findings show that two canonical functions were statistically significant. The set of variables (metacognitive self-regulation, source management, preparing homework, preparing for test and preparing term papers) helped predict changes of statistics anxiety with respect to fearful behavior, Attitude towards math and class, Performance, but not Anxiety. These findings could be used in educational and psychological interventions in the context of statistics anxiety reduction.
Wilderness adventure therapy effects on the mental health of youth participants.
Bowen, Daniel J; Neill, James T; Crisp, Simon J R
2016-10-01
Adventure therapy offers a prevention, early intervention, and treatment modality for people with behavioural, psychological, and psychosocial issues. It can appeal to youth-at-risk who are often less responsive to traditional psychotherapeutic interventions. This study evaluated Wilderness Adventure Therapy (WAT) outcomes based on participants' pre-program, post-program, and follow-up responses to self-report questionnaires. The sample consisted of 36 adolescent out-patients with mixed mental health issues who completed a 10-week, manualised WAT intervention. The overall short-term standardised mean effect size was small, positive, and statistically significant (0.26), with moderate, statistically significant improvements in psychological resilience and social self-esteem. Total short-term effects were within age-based adventure therapy meta-analytic benchmark 90% confidence intervals, except for the change in suicidality which was lower than the comparable benchmark. The short-term changes were retained at the three-month follow-up, except for family functioning (significant reduction) and suicidality (significant improvement). For participants in clinical ranges pre-program, there was a large, statistically significant reduction in depressive symptomology, and large to very large, statistically significant improvements in behavioural and emotional functioning. These changes were retained at the three-month follow-up. These findings indicate that WAT is as effective as traditional psychotherapy techniques for clinically symptomatic people. Future research utilising a comparison or wait-list control group, multiple sources of data, and a larger sample, could help to qualify and extend these findings. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.
Ethnicity and fertility in Nigeria.
Kollehlon, Konia T
2003-01-01
Using a sample of Hausa-Fulani, Yoruba, Ibo, and all other women from the 1990 Nigerian Demographic and Health Survey, this study examines ethnic fertility differentials in Nigeria within the context of the social characteristics and cultural hypotheses. Among all women, we find the net fertility of Hausa-Fulani women to be lower than that of Other women; with no statistically significant difference in the net fertility of Ibo, Yourba, and Other women. But, among currently married women, we find the net fertility of Hausa-Fulani and Yoruba women to be lower than that of Other women, while the net fertility of Ibo women is higher than that of Other women. Overall, the findings of this study are more consistent with the cultural hypothesis, because statistically significant fertility differentials by ethnicity remain, even after controlling for selected socioeconomic and demographic variables.
2016-01-01
We examine the impact of religious identity and village-level religious fragmentation on behavior in Tullock contests. We report on a series of two-player Tullock contest experiments conducted on a sample of 516 Hindu and Muslim participants in rural West Bengal, India. Our treatments are the identity of the two players and the degree of religious fragmentation in the village where subjects reside. Our main finding is that the effect of social identity is small and inconsistent across the two religious groups in our study. While we find small but statistically significant results in line with our hypotheses in the Hindu sample, we find no statistically significant effects in the Muslim sample. This is in contrast to evidence from Chakravarty et al. (2016), who report significant differences in cooperation levels in prisoners’ dilemma and stag hunt games, both in terms of village composition and identity. We attribute this to the fact that social identity may have a more powerful effect on cooperation than on conflict. PMID:27768713
Chakravarty, Surajeet; Fonseca, Miguel A; Ghosh, Sudeep; Marjit, Sugata
2016-01-01
We examine the impact of religious identity and village-level religious fragmentation on behavior in Tullock contests. We report on a series of two-player Tullock contest experiments conducted on a sample of 516 Hindu and Muslim participants in rural West Bengal, India. Our treatments are the identity of the two players and the degree of religious fragmentation in the village where subjects reside. Our main finding is that the effect of social identity is small and inconsistent across the two religious groups in our study. While we find small but statistically significant results in line with our hypotheses in the Hindu sample, we find no statistically significant effects in the Muslim sample. This is in contrast to evidence from Chakravarty et al. (2016), who report significant differences in cooperation levels in prisoners' dilemma and stag hunt games, both in terms of village composition and identity. We attribute this to the fact that social identity may have a more powerful effect on cooperation than on conflict.
Cosmic shear measurements with Dark Energy Survey Science Verification data
Becker, M. R.
2016-07-06
Here, we present measurements of weak gravitational lensing cosmic shear two-point statistics using Dark Energy Survey Science Verification data. We demonstrate that our results are robust to the choice of shear measurement pipeline, either ngmix or im3shape, and robust to the choice of two-point statistic, including both real and Fourier-space statistics. Our results pass a suite of null tests including tests for B-mode contamination and direct tests for any dependence of the two-point functions on a set of 16 observing conditions and galaxy properties, such as seeing, airmass, galaxy color, galaxy magnitude, etc. We use a large suite of simulationsmore » to compute the covariance matrix of the cosmic shear measurements and assign statistical significance to our null tests. We find that our covariance matrix is consistent with the halo model prediction, indicating that it has the appropriate level of halo sample variance. We also compare the same jackknife procedure applied to the data and the simulations in order to search for additional sources of noise not captured by the simulations. We find no statistically significant extra sources of noise in the data. The overall detection significance with tomography for our highest source density catalog is 9.7σ. Cosmological constraints from the measurements in this work are presented in a companion paper.« less
The earth is flat (p > 0.05): significance thresholds and the crisis of unreplicable research.
Amrhein, Valentin; Korner-Nievergelt, Fränzi; Roth, Tobias
2017-01-01
The widespread use of 'statistical significance' as a license for making a claim of a scientific finding leads to considerable distortion of the scientific process (according to the American Statistical Association). We review why degrading p -values into 'significant' and 'nonsignificant' contributes to making studies irreproducible, or to making them seem irreproducible. A major problem is that we tend to take small p -values at face value, but mistrust results with larger p -values. In either case, p -values tell little about reliability of research, because they are hardly replicable even if an alternative hypothesis is true. Also significance ( p ≤ 0.05) is hardly replicable: at a good statistical power of 80%, two studies will be 'conflicting', meaning that one is significant and the other is not, in one third of the cases if there is a true effect. A replication can therefore not be interpreted as having failed only because it is nonsignificant. Many apparent replication failures may thus reflect faulty judgment based on significance thresholds rather than a crisis of unreplicable research. Reliable conclusions on replicability and practical importance of a finding can only be drawn using cumulative evidence from multiple independent studies. However, applying significance thresholds makes cumulative knowledge unreliable. One reason is that with anything but ideal statistical power, significant effect sizes will be biased upwards. Interpreting inflated significant results while ignoring nonsignificant results will thus lead to wrong conclusions. But current incentives to hunt for significance lead to selective reporting and to publication bias against nonsignificant findings. Data dredging, p -hacking, and publication bias should be addressed by removing fixed significance thresholds. Consistent with the recommendations of the late Ronald Fisher, p -values should be interpreted as graded measures of the strength of evidence against the null hypothesis. Also larger p -values offer some evidence against the null hypothesis, and they cannot be interpreted as supporting the null hypothesis, falsely concluding that 'there is no effect'. Information on possible true effect sizes that are compatible with the data must be obtained from the point estimate, e.g., from a sample average, and from the interval estimate, such as a confidence interval. We review how confusion about interpretation of larger p -values can be traced back to historical disputes among the founders of modern statistics. We further discuss potential arguments against removing significance thresholds, for example that decision rules should rather be more stringent, that sample sizes could decrease, or that p -values should better be completely abandoned. We conclude that whatever method of statistical inference we use, dichotomous threshold thinking must give way to non-automated informed judgment.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Heicklen, J.; Lundgard, R.; Partymiller, K.
1982-04-01
Institute of Cancer Research Swiss strain mice were subjected to the inhalation of 10.3 +/- 3.7 ppm diethylhydroxylamine, 10.1 +/- 4.1 ppm nitroethane, and the vapor of diethylamine hydrogen sulfite for over 2 years. Histopathologic evaluation of all organs indicated only a few significant findings. The incidence of all tumors, as well as subcutaneous tumors (principally fibrosarcomas), increased in exposed males with marginal statistical significance (P = 0.12 and 0.048, respectively). The incidence of all tumors in exposed females decreased with marked statistical significance (P < 0.0005).
The fragility of statistically significant findings from randomized trials in head and neck surgery.
Noel, Christopher W; McMullen, Caitlin; Yao, Christopher; Monteiro, Eric; Goldstein, David P; Eskander, Antoine; de Almeida, John R
2018-04-23
The Fragility Index (FI) is a novel tool for evaluating the robustness of statistically significant findings in a randomized control trial (RCT). It measures the number of events upon which statistical significance depends. We sought to calculate the FI scores for RCTs in the head and neck cancer literature where surgery was a primary intervention. Potential articles were identified in PubMed (MEDLINE), Embase, and Cochrane without publication date restrictions. Two reviewers independently screened eligible RCTs reporting at least one dichotomous and statistically significant outcome. The data from each trial were extracted and the FI scores were calculated. Associations between trial characteristics and FI were determined. In total, 27 articles were identified. The median sample size was 67.5 (interquartile range [IQR] = 42-143) and the median number of events per trial was 8 (IQR = 2.25-18.25). The median FI score was 1 (IQR = 0-2.5), meaning that changing one patient from a nonevent to an event in the treatment arm would change the result to a statistically nonsignificant result, or P > .05. The FI score was less than the number of patients lost to follow-up in 71% of cases. The FI score was found to be moderately correlated with P value (ρ = -0.52, P = .007) and with journal impact factor (ρ = 0.49, P = .009) on univariable analysis. On multivariable analysis, only the P value was found to be a predictor of FI score (P = .001). Randomized trials in the head and neck cancer literature where surgery is a primary modality are relatively nonrobust statistically with low FI scores. Laryngoscope, 2018. © 2018 The American Laryngological, Rhinological and Otological Society, Inc.
Reisman, H; Martin, D; Gast, M J
1999-11-01
This study was undertaken to compare the effects of 2 oral contraceptive regimens on menstrual cycle control and laboratory findings. In a multicenter randomized study 100 microg levonorgestrel with 20 microg ethinyl estradiol (Alesse or Loette) was given to 155 healthy women. A triphasic preparation of 500, 750, and 1000 microg norethindrone with 35 microg ethinyl estradiol (Ortho-Novum 7/7/7 or TriNovum) was given to 167 women for 1 to 4 cycles of treatment. Overall, the percentages of normal menstrual cycles and the percentages of cycles with intermenstrual and withdrawal bleeding were similar between the 2 treatment groups. In the levonorgestrel with ethinyl estradiol group, there was a statistically significantly longer latent period and a statistically significantly shorter withdrawal bleeding episode. Adverse events were similar between treatment groups, and none were serious. Most mean changes from baseline laboratory values were comparable between groups, although the mean increase in cholesterol concentration was statistically significantly lower in the levonorgestrel with ethinyl estradiol group. Changes in triglyceride and glucose concentrations were not statistically significantly different between groups. Levonorgestrel (100 microg) with ethinyl estradiol (20 microg) provides menstrual cycle control equivalent to that obtained with triphasic norethindrone with ethinyl estradiol (75% higher estrogen dose) with similar safety and tolerability.
Schenone, Mauro; Ziebarth, Sarah; Duncan, Jose; Stokes, Lea; Hernandez, Angela
2018-02-05
To investigate the proportion of documented ultrasound findings that were unsupported by stored ultrasound images in the obstetric ultrasound unit, before and after the implementation of a quality improvement process consisting of a checklist and feedback. A quality improvement process was created involving utilization of a checklist and feedback from physician to sonographer. The feedback was based on findings of the physician's review of the report and images using a check list. To assess the impact of this process, two groups were compared. Group 1 consisted of 58 ultrasound reports created prior to initiation of the process. Group 2 included 65 ultrasound reports created after process implementation. Each chart was reviewed by a physician and a sonographer. Findings considered unsupported by stored images by both reviewers were used for analysis, and the proportion of unsupported findings was compared between the two groups. Results are expressed as mean ± standard error. A p value of < .05 was used to determine statistical significance. Univariate analysis of baseline characteristics and potential confounders showed no statistically significant difference between the groups. The mean proportion of unsupported findings in Group 1 was 5.1 ± 0.87, with Group 2 having a significantly lower proportion (2.6 ± 0.62) (p value = .018). Results suggest a significant decrease in the proportion of unsupported findings in ultrasound reports after quality improvement process implementation. Thus, we present a simple yet effective quality improvement process to reduce unsupported ultrasound findings.
Vahedi, Shahrum; Farrokhi, Farahman; Gahramani, Farahnaz; Issazadegan, Ali
2012-01-01
Objective: Approximately 66-80%of graduate students experience statistics anxiety and some researchers propose that many students identify statistics courses as the most anxiety-inducing courses in their academic curriculums. As such, it is likely that statistics anxiety is, in part, responsible for many students delaying enrollment in these courses for as long as possible. This paper proposes a canonical model by treating academic procrastination (AP), learning strategies (LS) as predictor variables and statistics anxiety (SA) as explained variables. Methods: A questionnaire survey was used for data collection and 246-college female student participated in this study. To examine the mutually independent relations between procrastination, learning strategies and statistics anxiety variables, a canonical correlation analysis was computed. Results: Findings show that two canonical functions were statistically significant. The set of variables (metacognitive self-regulation, source management, preparing homework, preparing for test and preparing term papers) helped predict changes of statistics anxiety with respect to fearful behavior, Attitude towards math and class, Performance, but not Anxiety. Conclusion: These findings could be used in educational and psychological interventions in the context of statistics anxiety reduction. PMID:24644468
Perceived organizational support and extra-role performance: which leads to which?
Chen, Zhixia; Eisenberger, Robert; Johnson, Kelly M; Sucharski, Ivan L; Aselage, Justin
2009-02-01
L. Rhoades and R. Eisenberger (2002) reported the meta-analytic finding of a highly statistically significant relation between perceived organizational support (POS) and performance but concluded that the reviewed studies' methodology allowed no conclusion concerning the direction of the association. To investigate this issue, the authors assessed POS and extra-role performance 2 times, separated by a 3-year interval, among 199 employees of an electronic and appliance sales organization. Using a cross-lagged panel design, the authors found that POS was positively associated with a temporal change in extra-role performance. In contrast, the relation between extra-role performance and temporal change in POS was not statistically significant. These findings provide evidence that POS leads to extra-role performance.
Assessing Online Homework in First-Semester Calculus
ERIC Educational Resources Information Center
Callahan, Jason T.
2016-01-01
This paper describes and assesses the implementation of online homework in a first-semester calculus course. Comparing sections of the course before implementation to those after, we find statistically significant improvements in retention rates, measures of student engagement, and participation on homework. We do not, however, find statistically…
Hashim, Muhammad Jawad
2010-09-01
Post-hoc secondary data analysis with no prespecified hypotheses has been discouraged by textbook authors and journal editors alike. Unfortunately no single term describes this phenomenon succinctly. I would like to coin the term "sigsearch" to define this practice and bring it within the teaching lexicon of statistics courses. Sigsearch would include any unplanned, post-hoc search for statistical significance using multiple comparisons of subgroups. It would also include data analysis with outcomes other than the prespecified primary outcome measure of a study as well as secondary data analyses of earlier research.
Ogneva-Himmelberger, Yelena; Dahlberg, Tyler; Kelly, Kristen; Simas, Tiffany A. Moore
2015-01-01
The study uses geographic information science (GIS) and statistics to find out if there are statistical differences between full term and preterm births to non-Hispanic white, non-Hispanic Black, and Hispanic mothers in their exposure to air pollution and access to environmental amenities (green space and vendors of healthy food) in the second largest city in New England, Worcester, Massachusetts. Proximity to a Toxic Release Inventory site has a statistically significant effect on preterm birth regardless of race. The air-pollution hazard score from the Risk Screening Environmental Indicators Model is also a statistically significant factor when preterm births are categorized into three groups based on the degree of prematurity. Proximity to green space and to a healthy food vendor did not have an effect on preterm births. The study also used cluster analysis and found statistically significant spatial clusters of high preterm birth volume for non-Hispanic white, non-Hispanic Black, and Hispanic mothers. PMID:29546120
Ogneva-Himmelberger, Yelena; Dahlberg, Tyler; Kelly, Kristen; Simas, Tiffany A Moore
2015-01-01
The study uses geographic information science (GIS) and statistics to find out if there are statistical differences between full term and preterm births to non-Hispanic white, non-Hispanic Black, and Hispanic mothers in their exposure to air pollution and access to environmental amenities (green space and vendors of healthy food) in the second largest city in New England, Worcester, Massachusetts. Proximity to a Toxic Release Inventory site has a statistically significant effect on preterm birth regardless of race. The air-pollution hazard score from the Risk Screening Environmental Indicators Model is also a statistically significant factor when preterm births are categorized into three groups based on the degree of prematurity. Proximity to green space and to a healthy food vendor did not have an effect on preterm births. The study also used cluster analysis and found statistically significant spatial clusters of high preterm birth volume for non-Hispanic white, non-Hispanic Black, and Hispanic mothers.
The earth is flat (p > 0.05): significance thresholds and the crisis of unreplicable research
Korner-Nievergelt, Fränzi; Roth, Tobias
2017-01-01
The widespread use of ‘statistical significance’ as a license for making a claim of a scientific finding leads to considerable distortion of the scientific process (according to the American Statistical Association). We review why degrading p-values into ‘significant’ and ‘nonsignificant’ contributes to making studies irreproducible, or to making them seem irreproducible. A major problem is that we tend to take small p-values at face value, but mistrust results with larger p-values. In either case, p-values tell little about reliability of research, because they are hardly replicable even if an alternative hypothesis is true. Also significance (p ≤ 0.05) is hardly replicable: at a good statistical power of 80%, two studies will be ‘conflicting’, meaning that one is significant and the other is not, in one third of the cases if there is a true effect. A replication can therefore not be interpreted as having failed only because it is nonsignificant. Many apparent replication failures may thus reflect faulty judgment based on significance thresholds rather than a crisis of unreplicable research. Reliable conclusions on replicability and practical importance of a finding can only be drawn using cumulative evidence from multiple independent studies. However, applying significance thresholds makes cumulative knowledge unreliable. One reason is that with anything but ideal statistical power, significant effect sizes will be biased upwards. Interpreting inflated significant results while ignoring nonsignificant results will thus lead to wrong conclusions. But current incentives to hunt for significance lead to selective reporting and to publication bias against nonsignificant findings. Data dredging, p-hacking, and publication bias should be addressed by removing fixed significance thresholds. Consistent with the recommendations of the late Ronald Fisher, p-values should be interpreted as graded measures of the strength of evidence against the null hypothesis. Also larger p-values offer some evidence against the null hypothesis, and they cannot be interpreted as supporting the null hypothesis, falsely concluding that ‘there is no effect’. Information on possible true effect sizes that are compatible with the data must be obtained from the point estimate, e.g., from a sample average, and from the interval estimate, such as a confidence interval. We review how confusion about interpretation of larger p-values can be traced back to historical disputes among the founders of modern statistics. We further discuss potential arguments against removing significance thresholds, for example that decision rules should rather be more stringent, that sample sizes could decrease, or that p-values should better be completely abandoned. We conclude that whatever method of statistical inference we use, dichotomous threshold thinking must give way to non-automated informed judgment. PMID:28698825
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…
Finding P-Values for F Tests of Hypothesis on a Spreadsheet.
ERIC Educational Resources Information Center
Rochowicz, John A., Jr.
The calculation of the F statistic for a one-factor analysis of variance (ANOVA) and the construction of an ANOVA tables are easily implemented on a spreadsheet. This paper describes how to compute the p-value (observed significance level) for a particular F statistic on a spreadsheet. Decision making on a spreadsheet and applications to the…
Castro, Tatiana X.; Cubel Garcia, Rita de Cássia N.; Gonçalves, Luciana P. S.; Costa, Erika M.; Marcello, Gracy C.G.; Labarthe, Norma V.; Mendes-de-Almeida, Flavya
2013-01-01
The clinical and laboratory findings in puppies naturally infected with canine coronavirus (CCoV) and/or canine parvovirus (CPV) were compared with findings in uninfected puppies. Lymphopenia was the only parameter related to CCoV infection that was statistically significant; vomiting, anorexia, lethargy, hemorrhagic fluid diarrhea, leukopenia, lymphopenia, thrombocytopenia, hypoglycemia, and hypoproteinemia were correlated with CPV infection. PMID:24155496
A study of correlations between crude oil spot and futures markets: A rolling sample test
NASA Astrophysics Data System (ADS)
Liu, Li; Wan, Jieqiu
2011-10-01
In this article, we investigate the asymmetries of exceedance correlations and cross-correlations between West Texas Intermediate (WTI) spot and futures markets. First, employing the test statistic proposed by Hong et al. [Asymmetries in stock returns: statistical tests and economic evaluation, Review of Financial Studies 20 (2007) 1547-1581], we find that the exceedance correlations were overall symmetric. However, the results from rolling windows show that some occasional events could induce the significant asymmetries of the exceedance correlations. Second, employing the test statistic proposed by Podobnik et al. [Quantifying cross-correlations using local and global detrending approaches, European Physics Journal B 71 (2009) 243-250], we find that the cross-correlations were significant even for large lagged orders. Using the detrended cross-correlation analysis proposed by Podobnik and Stanley [Detrended cross-correlation analysis: a new method for analyzing two nonstationary time series, Physics Review Letters 100 (2008) 084102], we find that the cross-correlations were weakly persistent and were stronger between spot and futures contract with larger maturity. Our results from rolling sample test also show the apparent effects of the exogenous events. Additionally, we have some relevant discussions on the obtained evidence.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Poyer, D.A.
In this report, tests of statistical significance of five sets of variables with household energy consumption (at the point of end-use) are described. Five models, in sequence, were empirically estimated and tested for statistical significance by using the Residential Energy Consumption Survey of the US Department of Energy, Energy Information Administration. Each model incorporated additional information, embodied in a set of variables not previously specified in the energy demand system. The variable sets were generally labeled as economic variables, weather variables, household-structure variables, end-use variables, and housing-type variables. The tests of statistical significance showed each of the variable sets tomore » be highly significant in explaining the overall variance in energy consumption. The findings imply that the contemporaneous interaction of different types of variables, and not just one exclusive set of variables, determines the level of household energy consumption.« less
Ziaee, Tayebe; Jannati, Yadollah; Mobasheri, Elham; Taghavi, Taraneh; Abdollahi, Habib; Modanloo, Mahnaz; Behnampour, Naser
2014-01-01
Objective: There are various elements affecting the healthy family such as marital satisfaction. Various factors such as sexual satisfaction have an important impact on satisfaction of marital relationship. The present study aimed to determine the association of marital satisfaction with sexual satisfaction among sexually active employee women. Methods: This analytical descriptive study was carried on 140 married women employed at educational and medical centers of Golestan University of Medical Sciences. Questionnaires for data collection included Enrich Marital Satisfaction Questionnaire and self-constructed questionnaire (demographic characteristic and sexual satisfaction). Data were analyzed using descriptive statistics, χ2 and Spearman statistical test. Statistical significant level was set as 0.05. Results: The findings showed that in marital satisfaction scale, the majority of the participants (63.6%) were very satisfied and none of them were very unsatisfied. In sexual satisfaction scale, most of the participants (56.4%) expressed extremely satisfaction rate and only 0.7% were not satisfied with their sexual relationship. Marital satisfaction was significantly associated with sexual satisfaction (p ≤ 0.001). So with the increase of sexual satisfaction, there was an increase in marital satisfaction accordingly. The findings indicated that there was a significant association between sexual satisfaction and age (p = 0.086). Level of education was associated significantly with the marital satisfaction (p = 0.038). The effects of sexual satisfaction on marital satisfaction were moderated by number of children and the level of education. Conclusion: The findings have implications for improving of couples' marital satisfaction by highlighting the need for awareness of sexual quality. According to the findings, it seems that development of educational programs and pre-marriage counseling is necessary. Continuous education would be helpful after marriage in addressing couples' unique transitional needs in marital life. PMID:25053956
Ziaee, Tayebe; Jannati, Yadollah; Mobasheri, Elham; Taghavi, Taraneh; Abdollahi, Habib; Modanloo, Mahnaz; Behnampour, Naser
2014-01-01
There are various elements affecting the healthy family such as marital satisfaction. Various factors such as sexual satisfaction have an important impact on satisfaction of marital relationship. The present study aimed to determine the association of marital satisfaction with sexual satisfaction among sexually active employee women. This analytical descriptive study was carried on 140 married women employed at educational and medical centers of Golestan University of Medical Sciences. Questionnaires for data collection included Enrich Marital Satisfaction Questionnaire and self-constructed questionnaire (demographic characteristic and sexual satisfaction). Data were analyzed using descriptive statistics, χ(2) and Spearman statistical test. Statistical significant level was set as 0.05. The findings showed that in marital satisfaction scale, the majority of the participants (63.6%) were very satisfied and none of them were very unsatisfied. In sexual satisfaction scale, most of the participants (56.4%) expressed extremely satisfaction rate and only 0.7% were not satisfied with their sexual relationship. Marital satisfaction was significantly associated with sexual satisfaction (p ≤ 0.001). So with the increase of sexual satisfaction, there was an increase in marital satisfaction accordingly. The findings indicated that there was a significant association between sexual satisfaction and age (p = 0.086). Level of education was associated significantly with the marital satisfaction (p = 0.038). The effects of sexual satisfaction on marital satisfaction were moderated by number of children and the level of education. The findings have implications for improving of couples' marital satisfaction by highlighting the need for awareness of sexual quality. According to the findings, it seems that development of educational programs and pre-marriage counseling is necessary. Continuous education would be helpful after marriage in addressing couples' unique transitional needs in marital life.
NASA Astrophysics Data System (ADS)
Kimball, Jorja; Cole, Bryan; Hobson, Margaret; Watson, Karan; Stanley, Christine
This paper reports findings on gender that were part of a larger study reviewing time to completion of course work that includes the first two semesters of calculus, chemistry, and physics, which are often considered the stumbling points or "barrier courses" to an engineering baccalaureate degree. Texas A&M University terms these courses core body of knowledge (CBK), and statistical analysis was conducted on two cohorts of first-year enrolling engineering students at the institution. Findings indicate that gender is statistically significantly related to completion of CBK with female engineering students completing required courses faster than males at the .01 level (p = 0.008). Statistical significance for gender and ethnicity was found between white male and white female students at the .01 level (p = 0.008). Descriptive analysis indicated that of the five majors studied (chemical, civil, computer, electrical, and mechanical engineering), women completed CBK faster than men, and African American and Hispanic women completed CBK faster than males of the same ethnicity.
Red blood cell metabolism (M114), part D. [in Skylab space flight simulation
NASA Technical Reports Server (NTRS)
Mengel, C. E.
1973-01-01
Statistically significant differences were found between Skylab simulation crews and controls for glycolytic enzymes. The absence of simultaneous controls for the pre- and postchamber analyses leaves the significance of the findings in the crew during these periods indeterminate.
Steve McNulty; Jennifer Moore Myers; Peter Caldwell; Ge Sun
2013-01-01
Key FindingsSince 1960, all but two southern capital cities (Montgomery, AL, and Oklahoma City, OK) have experienced a statistically significant increase in average annual temperature (approximately 0.016° C), but none has experienced significant trends in precipitation.The South is forecasted to experience warmer temperatures...
Bilateral preictal signature of phase-amplitude coupling in canine epilepsy.
Gagliano, Laura; Bou Assi, Elie; Nguyen, Dang K; Rihana, Sandy; Sawan, Mohamad
2018-01-01
Seizure forecasting would improve the quality of life of patients with refractory epilepsy. Although early findings were optimistic, no single feature has been found capable of individually characterizing brain dynamics during transition to seizure. Cross-frequency phase amplitude coupling has been recently proposed as a precursor of seizure activity. This work evaluates the existence of a statistically significant difference in mean phase amplitude coupling distribution between the preictal and interictal states of seizures in dogs with bilaterally implanted intracranial electrodes. Results show a statistically significant change (p<0.05) of phase amplitude coupling during the preictal phase. This change is correlated with the position of implanted electrodes and is more significant within high-gamma frequency bands. These findings highlight the potential benefit of bilateral iEEG analysis and the feasibility of seizure forecasting based on slow modulation of high frequency amplitude. Copyright © 2017 Elsevier B.V. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ackermann, M.; Ajello, M.; Allafort, A.
We present a detailed statistical analysis of the correlation between radio and gamma-ray emission of the active galactic nuclei (AGNs) detected by Fermi during its first year of operation, with the largest data sets ever used for this purpose. We use both archival interferometric 8.4 GHz data (from the Very Large Array and ATCA, for the full sample of 599 sources) and concurrent single-dish 15 GHz measurements from the Owens Valley Radio Observatory (OVRO, for a sub sample of 199 objects). Our unprecedentedly large sample permits us to assess with high accuracy the statistical significance of the correlation, using amore » surrogate data method designed to simultaneously account for common-distance bias and the effect of a limited dynamical range in the observed quantities. We find that the statistical significance of a positive correlation between the centimeter radio and the broadband (E > 100 MeV) gamma-ray energy flux is very high for the whole AGN sample, with a probability of <10{sup -7} for the correlation appearing by chance. Using the OVRO data, we find that concurrent data improve the significance of the correlation from 1.6 x 10{sup -6} to 9.0 x 10{sup -8}. Our large sample size allows us to study the dependence of correlation strength and significance on specific source types and gamma-ray energy band. We find that the correlation is very significant (chance probability < 10{sup -7}) for both flat spectrum radio quasars and BL Lac objects separately; a dependence of the correlation strength on the considered gamma-ray energy band is also present, but additional data will be necessary to constrain its significance.« less
Ackermann, M.; Ajello, M.; Allafort, A.; ...
2011-10-12
We present a detailed statistical analysis of the correlation between radio and gamma-ray emission of the active galactic nuclei (AGNs) detected by Fermi during its first year of operation, with the largest data sets ever used for this purpose. We use both archival interferometric 8.4 GHz data (from the Very Large Array and ATCA, for the full sample of 599 sources) and concurrent single-dish 15 GHz measurements from the Owens Valley Radio Observatory (OVRO, for a sub sample of 199 objects). Our unprecedentedly large sample permits us to assess with high accuracy the statistical significance of the correlation, using amore » surrogate data method designed to simultaneously account for common-distance bias and the effect of a limited dynamical range in the observed quantities. We find that the statistical significance of a positive correlation between the centimeter radio and the broadband (E > 100 MeV) gamma-ray energy flux is very high for the whole AGN sample, with a probability of <10 –7 for the correlation appearing by chance. Using the OVRO data, we find that concurrent data improve the significance of the correlation from 1.6 × 10 –6 to 9.0 × 10 –8. Our large sample size allows us to study the dependence of correlation strength and significance on specific source types and gamma-ray energy band. As a result, we find that the correlation is very significant (chance probability < 10 –7) for both flat spectrum radio quasars and BL Lac objects separately; a dependence of the correlation strength on the considered gamma-ray energy band is also present, but additional data will be necessary to constrain its significance.« less
NASA Technical Reports Server (NTRS)
Ackermann, M.; Ajello, M.; Allafort, A.; Angelakis, E.; Axelsson, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bellazzini, R.;
2011-01-01
We present a detailed statistical analysis of the correlation between radio and gamma-ray emission of the active galactic nuclei (AGNs) detected by Fermi during its first year of operation, with the largest data sets ever used for this purpose.We use both archival interferometric 8.4 GHz data (from the Very Large Array and ATCA, for the full sample of 599 sources) and concurrent single-dish 15 GHz measurements from the OwensValley RadioObservatory (OVRO, for a sub sample of 199 objects). Our unprecedentedly large sample permits us to assess with high accuracy the statistical significance of the correlation, using a surrogate data method designed to simultaneously account for common-distance bias and the effect of a limited dynamical range in the observed quantities. We find that the statistical significance of a positive correlation between the centimeter radio and the broadband (E > 100 MeV) gamma-ray energy flux is very high for the whole AGN sample, with a probability of <10(exp -7) for the correlation appearing by chance. Using the OVRO data, we find that concurrent data improve the significance of the correlation from 1.6 10(exp -6) to 9.0 10(exp -8). Our large sample size allows us to study the dependence of correlation strength and significance on specific source types and gamma-ray energy band. We find that the correlation is very significant (chance probability < 10(exp -7)) for both flat spectrum radio quasars and BL Lac objects separately; a dependence of the correlation strength on the considered gamma-ray energy band is also present, but additional data will be necessary to constrain its significance.
Magnetic resonance imaging findings in Ménière's disease.
Patel, V A; Oberman, B S; Zacharia, T T; Isildak, H
2017-07-01
To identify and evaluate cranial magnetic resonance imaging findings associated with Ménière's disease. Seventy-eight patients with a documented diagnosis of Ménière's disease and 35 controls underwent 1.5 T or 3 T magnetic resonance imaging of the brain. Patients also underwent otological, vestibular and audiometric examinations. Lack of visualisation of the left and right vestibular aqueducts was identified as statistically significant amongst Ménière's disease patients (left, p = 0.0001, odds ratio = 0.02; right, p = 0.0004, odds ratio = 0.03). Both vestibular aqueducts were of abnormal size in the Ménière's disease group, albeit with left-sided significance (left, p = 0.008, odds ratio = 10.91; right, p = 0.49, odds ratio = 2.47). Lack of vestibular aqueduct visualisation on magnetic resonance imaging was statistically significant in Ménière's disease patients compared to the general population. The study findings suggest that magnetic resonance imaging can be useful to rule out retrocochlear pathology and provide radiological data to support the clinical diagnosis of Ménière's disease.
Lee, Wonjae; Lee, Yoonje; Kim, Changsun; Choi, Hyuk Joong; Kang, Bossng; Lim, Tae Ho; Oh, Jaehoon; Kang, Hyunggoo; Shin, Junghun
2017-01-01
Objective We aimed to describe electrocardiographic (ECG) findings in spontaneous pneumothorax patients before and after closed thoracostomy. Methods This is a retrospective study which included patients with spontaneous pneumothorax who presented to an emergency department of a tertiary urban hospital from February 2005 to March 2015. The primary outcome was a difference in ECG findings between before and after closed thoracostomy. We specifically investigated the following ECG elements: PR, QRS, QTc, axis, ST segments, and R waves in each lead. The secondary outcomes were change in ST segment in any lead and change in axis after closed thoracostomy. Results There were two ECG elements which showed statistically significant difference after thoracostomy. With right pneumothorax volume of greater than 80%, QTc and the R waves in aVF and V5 significantly changed after thoracostomy. With left pneumothorax volume between 31% and 80%, the ST segment in V2 and the R wave in V1 significantly changed after thoracostomy. However, majority of ECG elements did not show statistically significant alteration after thoracostomy. Conclusion We found only minor changes in ECG after closed thoracostomy in spontaneous pneumothorax patients. PMID:28435901
Uzunhasan, Isil; Yildiz, Ahmet; Coskun, Ugur; Kalyoncuoglu, Muhsin; Baskurt, Murat; Cakar, Mehmet Akif; Kaya, Aysem; Pehlivanoglu, Seckin; Enar, Rasim; Okcun, Baris
2009-01-01
Heart failure is frequently a serious complication of acute myocardial infarction (AMI). ACE inhibitors, Angiotensin II receptor blockers, beta-blockers and aldosterone receptor blockers have been shown to improve outcomes in this setting. This study aimed to determine the effect of spironolactone on the frequency of clinical heart failure, mortality, rehospitalization and left ventricular functions determined by echocardiography. A total of 82 patients with STEMI hospitalized within 6-12 h of debut of symptoms were included in the study. The patients were randomly assigned into spironolactone (group A) or placebo (group B) groups after informed consent had been obtained. All patients were followed for 6 months. There were no statistically significant differences between the two groups when demographic criteria were compared. The incidence of post-MI angina pectoris, rhythm and conduction disturbance during hospitalization was significantly higher in Group B than in Group A. Although not statistically significant, the incidence of clinical heart failure was slightly lower in Group A than in Group B (5% versus 11%). Left ventricular end-diastolic volumes were slightly lower in Group A than in Group B, although statistically this was not significant. In concordance with these findings, the ejection fraction was slightly higher in Group A than in Group B, although this was not statistically significant (47% versus 44%). This trend continued during a 6-month follow-up after randomization. Our findings suggest that early administration of aldosterone blockers provides additional benefits after AMI, reducing the incidence of post-MI angina pectoris and rhythm and conduction disturbances.
An Investigation of Leadership Styles and Psychological Contracts
ERIC Educational Resources Information Center
Chu, Hui-Chin; Fu, Chi-Jung
2005-01-01
This study was conducted to determine whether a statistically significant relationship exists between the leadership styles of managers and employee psychological contracts, as perceived by the employees. The findings indicated that the employees' perception of leadership style significantly affected satisfaction levels of employee psychological…
Econometric Assessment of "One Minute" Paper as a Pedagogic Tool
ERIC Educational Resources Information Center
Das, Amaresh
2010-01-01
This paper makes an econometric testing of one-minute paper used as a tool to manage and assess instruction in my statistics class. One of our findings is that the one minute paper when I have tested it by using an OLS estimate in a controlled Vs experimental design framework is found to statistically significant and effective in enhancing…
Effect of water extract of Turkish propolis on tuberculosis infection in guinea-pigs.
Yildirim, Zeki; Hacievliyagil, Süleyman; Kutlu, Nurettin Onur; Aydin, Nasuhi Engin; Kurkcuoglu, Mine; Iraz, Mustafa; Durmaz, Riza
2004-03-01
Mycobacterium tuberculosis (H(37)R(v))-infected guinea-pig model was used to investigate the effect of water extract of propolis (WEP). After subcutaneous inoculation of tubercle bacilli, each animal received oral WEP (n=9), isoniazid (n=5) or saline (n=6) as placebo and were sacrificed 30 days later. Formation of necrosis was less prominent in the group treated with WEP, but was not statistically significant (P>0.05). The granuloma formation in the same group was more prominent than the placebo and isoniazid groups; however, this finding failed to reach statistical significance by the Kruskal-Wallis test (P>0.05). These findings suggest that Turkish WEP may have a limited effect on the development of tuberculosis infection in this guinea-pig model.
Invited Commentary: Can Issues With Reproducibility in Science Be Blamed on Hypothesis Testing?
Weinberg, Clarice R.
2017-01-01
Abstract In the accompanying article (Am J Epidemiol. 2017;186(6):646–647), Dr. Timothy Lash makes a forceful case that the problems with reproducibility in science stem from our “culture” of null hypothesis significance testing. He notes that when attention is selectively given to statistically significant findings, the estimated effects will be systematically biased away from the null. Here I revisit the recent history of genetic epidemiology and argue for retaining statistical testing as an important part of the tool kit. Particularly when many factors are considered in an agnostic way, in what Lash calls “innovative” research, investigators need a selection strategy to identify which findings are most likely to be genuine, and hence worthy of further study. PMID:28938713
Ocular disorders in children with spastic subtype of cerebral palsy.
Ozturk, A Taylan; Berk, A Tulin; Yaman, Aylin
2013-01-01
To document common ocular abnormalities in children with spastic subtype of cerebral palsy (CP) and to find out whether any correlation exists between their occurance and etiologic factors. Totally 194 patients with the diagnosis of spastic type CP were enrolled in this retrospective study. Detailed ophthalmic examinations were performed. Demographic data and neuroradiological findings were documented. Kruskal-Wallis, Mann Whitney U, Pearson Chi-square tests and Student's t tests were used in the statistical analysis. The mean age was 64.7±44.2 months on the first ophthalmic examination. Prevalences of diplegia (47.4%) and tetraplegia (36.1%) were found to be higher than the frequency of hemiplegia (16.5%) in our study population. Etiologic factor was asphyxia in 60.8% of the patients. Abnormal ocular findings were present in 78.9% of the patients. Statistically significant poor vision was detected in tetraplegia group among all the spastic ubtypes of CP (P=0.000). Anisometropia and significant refractive error were found in 14.4% and 70.1% of the patients, respectively. Thirty-six children (18.6%) had nystagmus and 107 children (55.2%) had strabismus. Lower gestational age and birth weight were statistically higher in patients with esotropia than exotropia (P=0.009 and P=0.024, respectively). Abnormal morphology of the optic disc was present in 152 eyes (39.2%). Severe periventricular leukomalacia (PVL) was found in 48 patients and statistically significant poor vision was detected in the presence of PVL (P=0.000). Spastic diplegic or tetraplegic CP patients with positive neuroradiological symptoms, younger gestational age and lower birth weight ought to have detailed ophthalmic examinations as early as possible to provide best visual rehabilitation.
Ku, Yi-Kang; Wong, Yon-Cheong; Fu, Chen-Ju; Tseng, Hsiao-Jung; Wang, Li-Jen; Wang, Chao-Jan; Chin, Shy-Chyi
2016-04-01
We investigated the timing of CT and MRI performed before digital subtraction angiography (DSA) in the prediction of hemorrhage sites in patients with head and neck cancers who present with acute oral or neck bleeding after receiving treatment. A total of 123 DSA examinations that evaluated 123 oral or neck bleeding events in 85 patients were analyzed. The last CT or MRI examinations performed within a time frame of 0-337 days before transarterial embolization were reviewed retrospectively, with three findings (pseudoaneurysm, air-containing necrotic tissue, and residual tumor) used to predict hemorrhage sites. DSA findings of pseudoaneurysm or active contrast extravasation were used as a reference standard. The sensitivity of CT and MRI for correctly predicting hemorrhage sites was used to determine the optimal timing of CT or MRI examinations performed before DSA. A total of 8.9% of the DSA examinations (11/123) had equivocal findings but were followed by another bleeding event for which DSA findings were positive. CT or MRI was statistically significantly better at predicting hemorrhage sites in patients with bleeding events associated with nonhypopharyngeal cancers (p = 0.019) than in those with bleeding events associated with hypopharyngeal cancers. The sensitivity of CT or MRI in the prediction of hemorrhage sites was statistically significantly higher for the common carotid artery and the internal carotid artery when CT or MRI was performed less than 30 days before bleeding events occurred. Prediction of hemorrhagic sites was better with the use of CT angiography than with the use of enhanced CT or MRI, although it was not statistically significant. DSA findings can temporarily be equivocal. CT or MRI examinations performed within 30 days of bleeding events can predict the site of hemorrhage. If no CT or MRI findings from the past 30 days are available, we suggest performing emergent CT angiography for the sake of obtaining better arterial detail.
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.
NASA Astrophysics Data System (ADS)
Sinha, Manodeep; Berlind, Andreas A.; McBride, Cameron K.; Scoccimarro, Roman; Piscionere, Jennifer A.; Wibking, Benjamin D.
2018-04-01
Interpreting the small-scale clustering of galaxies with halo models can elucidate the connection between galaxies and dark matter halos. Unfortunately, the modelling is typically not sufficiently accurate for ruling out models statistically. It is thus difficult to use the information encoded in small scales to test cosmological models or probe subtle features of the galaxy-halo connection. In this paper, we attempt to push halo modelling into the "accurate" regime with a fully numerical mock-based methodology and careful treatment of statistical and systematic errors. With our forward-modelling approach, we can incorporate clustering statistics beyond the traditional two-point statistics. We use this modelling methodology to test the standard ΛCDM + halo model against the clustering of SDSS DR7 galaxies. Specifically, we use the projected correlation function, group multiplicity function and galaxy number density as constraints. We find that while the model fits each statistic separately, it struggles to fit them simultaneously. Adding group statistics leads to a more stringent test of the model and significantly tighter constraints on model parameters. We explore the impact of varying the adopted halo definition and cosmological model and find that changing the cosmology makes a significant difference. The most successful model we tried (Planck cosmology with Mvir halos) matches the clustering of low luminosity galaxies, but exhibits a 2.3σ tension with the clustering of luminous galaxies, thus providing evidence that the "standard" halo model needs to be extended. This work opens the door to adding interesting freedom to the halo model and including additional clustering statistics as constraints.
Preparing and Presenting Effective Research Posters
Miller, Jane E
2007-01-01
Objectives Posters are a common way to present results of a statistical analysis, program evaluation, or other project at professional conferences. Often, researchers fail to recognize the unique nature of the format, which is a hybrid of a published paper and an oral presentation. This methods note demonstrates how to design research posters to convey study objectives, methods, findings, and implications effectively to varied professional audiences. Methods A review of existing literature on research communication and poster design is used to identify and demonstrate important considerations for poster content and layout. Guidelines on how to write about statistical methods, results, and statistical significance are illustrated with samples of ineffective writing annotated to point out weaknesses, accompanied by concrete examples and explanations of improved presentation. A comparison of the content and format of papers, speeches, and posters is also provided. Findings Each component of a research poster about a quantitative analysis should be adapted to the audience and format, with complex statistical results translated into simplified charts, tables, and bulleted text to convey findings as part of a clear, focused story line. Conclusions Effective research posters should be designed around two or three key findings with accompanying handouts and narrative description to supply additional technical detail and encourage dialog with poster viewers. PMID:17355594
Low statistical power in biomedical science: a review of three human research domains.
Dumas-Mallet, Estelle; Button, Katherine S; Boraud, Thomas; Gonon, Francois; Munafò, Marcus R
2017-02-01
Studies with low statistical power increase the likelihood that a statistically significant finding represents a false positive result. We conducted a review of meta-analyses of studies investigating the association of biological, environmental or cognitive parameters with neurological, psychiatric and somatic diseases, excluding treatment studies, in order to estimate the average statistical power across these domains. Taking the effect size indicated by a meta-analysis as the best estimate of the likely true effect size, and assuming a threshold for declaring statistical significance of 5%, we found that approximately 50% of studies have statistical power in the 0-10% or 11-20% range, well below the minimum of 80% that is often considered conventional. Studies with low statistical power appear to be common in the biomedical sciences, at least in the specific subject areas captured by our search strategy. However, we also observe evidence that this depends in part on research methodology, with candidate gene studies showing very low average power and studies using cognitive/behavioural measures showing high average power. This warrants further investigation.
Low statistical power in biomedical science: a review of three human research domains
Dumas-Mallet, Estelle; Button, Katherine S.; Boraud, Thomas; Gonon, Francois
2017-01-01
Studies with low statistical power increase the likelihood that a statistically significant finding represents a false positive result. We conducted a review of meta-analyses of studies investigating the association of biological, environmental or cognitive parameters with neurological, psychiatric and somatic diseases, excluding treatment studies, in order to estimate the average statistical power across these domains. Taking the effect size indicated by a meta-analysis as the best estimate of the likely true effect size, and assuming a threshold for declaring statistical significance of 5%, we found that approximately 50% of studies have statistical power in the 0–10% or 11–20% range, well below the minimum of 80% that is often considered conventional. Studies with low statistical power appear to be common in the biomedical sciences, at least in the specific subject areas captured by our search strategy. However, we also observe evidence that this depends in part on research methodology, with candidate gene studies showing very low average power and studies using cognitive/behavioural measures showing high average power. This warrants further investigation. PMID:28386409
Brain Lesions in Children with Unilateral Spastic Cerebral Palsy.
Hadzagic-Catibusic, Feriha; Avdagic, Edin; Zubcevic, Smail; Uzicanin, Sajra
2017-02-01
Unilateral spastic cerebral palsy (US CP) is the second most common subtype of cerebral palsy. The aim of the study was to analyze neuroimaging findings in children with unilateral spastic cerebral palsy. The study was hospital based, which has included 106 patients with US CP (boys 72/girls 34, term 82/preterm 24). Neuroimaging findings were classified into 5 groups: Brain maldevelopment, predominant white matter injury, predominant gray matter injury, non specific findings and normal neuroimaging findings. Predominant white matter lesions where the most frequent (48/106,45.28%; term 35/preterm 13), without statistically significant difference between term and preterm born children (x2=0.4357; p=0.490517). Predominant gray matter lesions had 32/106 children, 30.19%; (term 25/preterm 7, without statistically significant difference between term and preterm born children (x2=0.902; p=0.9862). Brain malformations had 10/106 children, 9.43%, and all of them were term born. Other finding had 2/106 children, 1.89%, both of them were term born. Normal neuroimaging findings were present in14/106 patients (13.21%). Neuroimaging may help to understand morphological background of motor impairment in children with US CP. Periventricular white matter lesions were the most frequent, then gray matter lesions.
Role of urodynamics in stress urinary incontinence: A critical appraisal
Yande, Shirish Dattatraya; Joglekar, Omkar Vinay; Joshi, Maya
2016-01-01
Introduction: Role of urodynamics prior to surgery of stress urinary incontinence (SUI) is under constant debate. Demonstration of the presence of detrusor overactivity is the only aspect that has been emphasized in the literature so far. We believe that there are number of other factors which may influence the evaluation and in turn the choice of surgical management and prediction of outcome of treatment. They are as follows: (1) Presence of voiding inefficiency, (2) asymptomatic detrusor overactivity, (3) and severity of SUI. These features may complicate the precise evaluation of patients of SUI. The main objective of this study is to analyze the dynamics of leakage and voiding using urodynamics. This study also aims at correlating these findings with clinical information. Materials and Methods: One hundred consecutive cases referred to our center for preoperative evaluation of SUI were recruited in the study prospectively. All patients were interrogated using International Consultation on Incontinence Questionnaire. All patients underwent complete urodynamic evaluation including uroflowmetry, filling cystometry, leak point pressure measurement, and pressure flow studies, according to Good Urodynamic Practice guidelines. Patients’ symptoms were correlated with urodynamic findings, with special emphasis on the presence of detrusor overactivity, severity of SUI, voiding efficiency, and presence of bladder outlet obstruction. Clinical information and urodynamic findings were correlated using Chi-square test. Results: There is a statistically significant correlation between the presence of symptoms of urge urinary incontinence and urodynamic findings of detrusor overactivity at P < 0.05. There is a statistically significant correlation between the symptoms of urge incontinence (in addition to SUI) and urodynamic findings of intrinsic sphincter deficiency at P < 0.05. Fifteen of 51 patients who did not have associated storage symptoms were found to have some degree of detrusor overactivity on urodynamic evaluation. There was no statistically significant correlation between asymptomatic cases of urge incontinence and incidental finding of detrusor overactivity at P < 0.05. There is no statistically significant correlation between the urodynamic findings of symptoms of voiding dysfunction and urodynamic findings, suggestive of the same value at P < 0.05. Conclusions: Urodynamic study in SUI has a potential of giving much more information than demonstration of Detrusor Overactivity alone. The predominant symptom of urge urinary incontinence can predictably diagnose detrusor overactivity in these cases. However, the incidence of asymptomatic detrusor overactivity remains as high as 15% and may have implication in postoperative results. This study clearly shows that there is a definite incidence of significant voiding dysfunction, which cannot be reliably evaluated without properly conducted pressure flow study. This factor may govern the choice of correct treatment which also predicts the outcome more reliably. Preoperative urodynamic study thus adds a dimension of precision to evaluation of the patients of SUI and may also influence technique and outcome measures in this group of patients. PMID:27721639
Salt preference: age and sex related variability.
Verma, Punam; Mittal, Sunita; Ghildiyal, Archana; Chaudhary, Lalita; Mahajan, K K
2007-01-01
Salt preference was assessed in 60 adults of 18-21 yrs of age (30 males and 30 females) and in 60 children of 7-12 yrs of age (30 boys and 30 girls). Subjects rated the preference on Likert scale for popcorns of five salt concentrations (OM, 1M, 2M, 3M and +3M). Statistical analysis using Two way ANOVA revealed statistically significant effect of age and sex on salt preference (F4,100 = 15.027, P < 0.01) and One Way ANOVA revealed statistically significant sex difference in salt preference of adults (F4,50 = 16.26, P < 0.01) but no statistically significant sex difference in salt preference of children (F4,50 = 4.08, P > 0.05). Dietary experiences during development and more physical activity in children may be responsible for higher salt preference in children while finding no sex variability in children favours the role of sex hormones in salt preference of male and females.
Identifying irregularly shaped crime hot-spots using a multiobjective evolutionary algorithm
NASA Astrophysics Data System (ADS)
Wu, Xiaolan; Grubesic, Tony H.
2010-12-01
Spatial cluster detection techniques are widely used in criminology, geography, epidemiology, and other fields. In particular, spatial scan statistics are popular and efficient techniques for detecting areas of elevated crime or disease events. The majority of spatial scan approaches attempt to delineate geographic zones by evaluating the significance of clusters using likelihood ratio statistics tested with the Poisson distribution. While this can be effective, many scan statistics give preference to circular clusters, diminishing their ability to identify elongated and/or irregular shaped clusters. Although adjusting the shape of the scan window can mitigate some of these problems, both the significance of irregular clusters and their spatial structure must be accounted for in a meaningful way. This paper utilizes a multiobjective evolutionary algorithm to find clusters with maximum significance while quantitatively tracking their geographic structure. Crime data for the city of Cincinnati are utilized to demonstrate the advantages of the new approach and highlight its benefits versus more traditional scan statistics.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Firestone, Jeremy; Hoen, Ben; Rand, Joseph
In 2016, we undertook a nationally representative wind power perceptions survey of individuals living within 8 km of over 600 projects in the United States, generating 1705 telephone, web, and mail responses. We sought information on a variety of topics, including procedural fairness and its relationship to project attitude, the foci of the present analysis. Here, we present a series of descriptive statistics and regression results, emphasizing those residents who were aware of their local project prior to construction. Sample weighting is employed to account for stratification and non-response. We find that a developer being open and transparent, a communitymore » being able to influence the outcome, and having a say in the planning process are all statistically significant predictors of a process perceived as being ‘fair,’ with an open and transparent developer having the largest effect. We also find developer transparency and ability to influence outcomes to have statistically significant relationships to a more positive attitude, with those findings holding when aesthetics, landscape, and wind turbine sound considerations are controlled for. The results indicate that jurisdictions might consider developing procedures, which ensure citizens are consulted and heard, and benchmarks or best practices for developer interaction with communities and citizens.« less
Firestone, Jeremy; Hoen, Ben; Rand, Joseph; ...
2017-12-21
In 2016, we undertook a nationally representative wind power perceptions survey of individuals living within 8 km of over 600 projects in the United States, generating 1705 telephone, web, and mail responses. We sought information on a variety of topics, including procedural fairness and its relationship to project attitude, the foci of the present analysis. Here, we present a series of descriptive statistics and regression results, emphasizing those residents who were aware of their local project prior to construction. Sample weighting is employed to account for stratification and non-response. We find that a developer being open and transparent, a communitymore » being able to influence the outcome, and having a say in the planning process are all statistically significant predictors of a process perceived as being ‘fair,’ with an open and transparent developer having the largest effect. We also find developer transparency and ability to influence outcomes to have statistically significant relationships to a more positive attitude, with those findings holding when aesthetics, landscape, and wind turbine sound considerations are controlled for. The results indicate that jurisdictions might consider developing procedures, which ensure citizens are consulted and heard, and benchmarks or best practices for developer interaction with communities and citizens.« less
Open vs Laparoscopic Simple Prostatectomy: A Comparison of Initial Outcomes and Cost.
Demir, Aslan; Günseren, Kadir Ömür; Kordan, Yakup; Yavaşçaoğlu, İsmet; Vuruşkan, Berna Aytaç; Vuruşkan, Hakan
2016-08-01
We compared the cost-effectiveness of laparoscopic simple prostatectomy (LSP) vs open prostatectomy (OP). A total of 73 men treated for benign prostatic hyperplasia were enrolled for OP and LSP in groups 1 and 2, respectively. The findings were recorded perioperative, including operation time (OT), blood lost, transfusion rate, conversion to the open surgery, and the complications according to the Clavien Classification. The postoperative findings, including catheterization and drainage time, the amount of analgesic used, hospitalization time, postoperative complications, international prostate symptom score (IPSS) and International Index of Erectile Function (IIEF) scores, the extracted prostate weight, the uroflowmeter, as well as postvoiding residual (PVR) and quality of life (QoL) score at the postoperative third month, were analyzed. The cost of both techniques was also compared statistically. No statistical differences were found in the preoperative parameters, including age, IPSS and QoL score, maximum flow rate (Qmax), PVR, IIEF score, and prostate volumes, as measured by transabdominal ultrasonography. No statistical differences were established in terms of the OT and the weight of the extracted prostate. No differences were established with regard to complications according to Clavien's classification in groups. However, the bleeding rate was significantly lower in group 2. The drainage, catheterization, and hospitalization times and the amount of analgesics were significantly lower in the second group. The postoperative third month findings were not different statistically. Only the Qmax values were significantly greater in group 2. While there was only a $52 difference between groups with regard to operation cost, this difference was significantly different. The use of LSP for the prostates over 80 g is more effective than the OP in terms of OT, bleeding amount, transfusion rates, catheterization time, drain removal time, hospitalization time, consumed analgesic amount, and Qmax values. On the other hand, the mean cost of the LSP is higher than OP. Better effectiveness comes with higher cost.
Stethoscope vs. ultrasound probe - which is more reliable in children with suspected pneumonia?
Lovrenski, Jovan; Petrović, Slobodanka; Balj-Barbir, Svetlana; Jokić, Radoica; Vilotijević-Dautović, Gordana
2016-05-01
To compare lung ultrasound (LUS) with auscultation findings in children with clinical suspicion of pneumonia. A prospective study including 95 patients (age: from 2 months to 17.5 years; mean age: 5.1 y, SD 4.5 y) with referral diagnosis of suspected pneumonia. In all patients LUS and auscultatory examinations were performed within an hour. These findings were compared separately in each hemithorax. The radiologist performing LUS was blinded to the patient's clinical information. Positive auscultatory findings included: crackles and/or abnormal breath sounds (decreased, asymmetric, absent, or bronchial). For LUS examinations a combined transthoracic - transabdominal approach was used. A pneumonia-positive LUS finding included subpleural consolidation with air-bronchogram, or an adjacent area of interstitial edema. For each subpleural consolidation the cranio-caudal (CC) diameter was measured, and 95% confidence intervals (CI) of the sizes of subpleural consolidations for positive and negative auscultatory findings were compared. The p-value between LUS and auscultation was calculated using McNemar's test. LUS and auscultation showed pneumonia-positive findings in 98 and 64 hemithoraces, i.e. in 67 and 45 patients respectively. In positive auscultatory findings the CI for CC diameters of subpleural consolidations ranged from 32.46 to 54.14 mm, and in negative auscultatory findings the CI was between 16.52 and 29.83 mm, which showed a statistically significant difference. McNemar's test showed a statistically significant difference between LUS and auscultation. LUS showed positive findings in more hemithoraces than auscultation in children with suspected pneumonia. A cranio-caudal size of subpleural consolidation of less than 30 mm significantly reduces the possibility of auscultatory detection. Copyright © 2016 by Academy of Sciences and Arts of Bosnia and Herzegovina.
Social support and nocturnal blood pressure dipping: a systematic review.
Fortmann, Addie L; Gallo, Linda C
2013-03-01
Attenuated nocturnal blood pressure (BP) dipping is a better predictor of cardiovascular disease (CVD) morbidity and mortality than resting BP measurements. Studies have reported associations between social support, variously defined, and BP dipping. A systematic review of the literature was conducted to investigate associations of functional and structural social support with nocturnal BP dipping assessed over a minimum of 24 hours. A total of 297 articles were identified. Of these, 11 met criteria for inclusion; all studies were cross-sectional in design and included adult participants only (mean age = 19 to 72 years). Evidence was most consistent for an association between functional support and BP dipping, such that 5 of 7 studies reported statistically (or marginally) significant positive associations with BP dipping. Statistically significant functional support-BP dipping associations were moderate (standardized effect size (d) = 0.41) to large (d = 2.01) in magnitude. Studies examining structural support were fewer and relatively less consistent; however, preliminary evidence was observed for associations of marital status and social contact frequency with BP dipping. Statistically significant structural support findings were medium (d = 0.53) to large (d = 1.13) in magnitude. Overall, findings suggest a link between higher levels of functional support and greater nocturnal BP dipping; preliminary evidence was also observed for the protective effects of marriage and social contact frequency. Nonetheless, the relatively small number of studies conducted to date and the heterogeneity of findings across meaningful subgroups suggest that additional research is needed to substantiate these conclusions.
Farjo, Nadia; Turpin, David L; Coley, R Yates; Feng, Jianying
2015-06-01
In this study, we aimed to give insight into the article review process by investigating the characteristics and the fate of manuscripts submitted to the American Journal of Orthodontics and Dentofacial Orthopedics (AJO-DO). The following information was obtained for original articles submitted to the AJO-DO in 2008: (1) for rejected articles: the reasons for rejection and the journal of subsequent publication when applicable; (2) for accepted articles: the number of revisions and the time elapsed to publication; and (3) for all articles: study topic, study design, area of origin, and statistically significant findings. Findings were reported using descriptive statistics, the chi-square test for equality of proportions, and multiple regression where appropriate. Post-hoc pair-wise tests were checked against the Bonferroni correction to account for multiple testing. Of the 440 original articles submitted to AJO-DO in 2008, 116 (26%) were accepted and published an average of 21 months (SD, 5 months) after acceptance. Rejected articles totaled 324 (74%), with 137 (42%) finding subsequent publication an average of 22 months (SD, 11 months) after rejection by the AJO-DO. The top 3 reasons for rejection by the AJO-DO were (1) poor study design (59% of rejected articles), (2) outdated or unoriginal topic (42%), and (3) inappropriate for the AJO-DO's audience (27%). Manuscripts rejected for poor study design had the least success for subsequent publication, whereas those rejected as inappropriate for the AJO-DO had the highest rate of publication elsewhere. Area of origin was significantly associated with acceptance by the AJO-DO, with articles from United States and Canada most likely to be accepted (P < 0.01). Articles from countries with the lowest publication rate in the AJO-DO had the highest publication rate elsewhere. The presence of statistically significant findings was shown to be significantly associated with acceptance by the AJO-DO (P = 0.013) but not with publication elsewhere (P = 0.77). Rejection by the AJO-DO does not preclude publication elsewhere, although articles rejected for poor study design were least likely to be eventually published. Many publishable articles are rejected by the AJO-DO as inappropriate for its readership, and these were the most likely to find publication elsewhere. Articles with the highest chance of acceptance by the AJO-DO were those from the United States and Canada and those reporting statistically significant results. Copyright © 2015 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.
Cristea, Ioana Alina
2018-01-01
P values represent a widely used, but pervasively misunderstood and fiercely contested method of scientific inference. Display items, such as figures and tables, often containing the main results, are an important source of P values. We conducted a survey comparing the overall use of P values and the occurrence of significant P values in display items of a sample of articles in the three top multidisciplinary journals (Nature, Science, PNAS) in 2017 and, respectively, in 1997. We also examined the reporting of multiplicity corrections and its potential influence on the proportion of statistically significant P values. Our findings demonstrated substantial and growing reliance on P values in display items, with increases of 2.5 to 14.5 times in 2017 compared to 1997. The overwhelming majority of P values (94%, 95% confidence interval [CI] 92% to 96%) were statistically significant. Methods to adjust for multiplicity were almost non-existent in 1997, but reported in many articles relying on P values in 2017 (Nature 68%, Science 48%, PNAS 38%). In their absence, almost all reported P values were statistically significant (98%, 95% CI 96% to 99%). Conversely, when any multiplicity corrections were described, 88% (95% CI 82% to 93%) of reported P values were statistically significant. Use of Bayesian methods was scant (2.5%) and rarely (0.7%) articles relied exclusively on Bayesian statistics. Overall, wider appreciation of the need for multiplicity corrections is a welcome evolution, but the rapid growth of reliance on P values and implausibly high rates of reported statistical significance are worrisome. PMID:29763472
Cristea, Ioana Alina; Ioannidis, John P A
2018-01-01
P values represent a widely used, but pervasively misunderstood and fiercely contested method of scientific inference. Display items, such as figures and tables, often containing the main results, are an important source of P values. We conducted a survey comparing the overall use of P values and the occurrence of significant P values in display items of a sample of articles in the three top multidisciplinary journals (Nature, Science, PNAS) in 2017 and, respectively, in 1997. We also examined the reporting of multiplicity corrections and its potential influence on the proportion of statistically significant P values. Our findings demonstrated substantial and growing reliance on P values in display items, with increases of 2.5 to 14.5 times in 2017 compared to 1997. The overwhelming majority of P values (94%, 95% confidence interval [CI] 92% to 96%) were statistically significant. Methods to adjust for multiplicity were almost non-existent in 1997, but reported in many articles relying on P values in 2017 (Nature 68%, Science 48%, PNAS 38%). In their absence, almost all reported P values were statistically significant (98%, 95% CI 96% to 99%). Conversely, when any multiplicity corrections were described, 88% (95% CI 82% to 93%) of reported P values were statistically significant. Use of Bayesian methods was scant (2.5%) and rarely (0.7%) articles relied exclusively on Bayesian statistics. Overall, wider appreciation of the need for multiplicity corrections is a welcome evolution, but the rapid growth of reliance on P values and implausibly high rates of reported statistical significance are worrisome.
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.
Şenel, Engin; Satılmış, Özgür; Acar, Bilal
2015-01-01
Tularemia is a serious and potentially life-threatening zoonosis caused by Francisella tularensis, a highly infective, gram-negative coccobacillus. Although there are plenty of case reports and studies of tularemia outbreaks, the literature is lacking in reports on dermatologic manifestations of the disease. This study aimed to identify skin manifestations in clinical forms of tularemia. A total of 151 patients diagnosed with tularemia at Çankırı State Hospital, Çankırı, Turkey, were retrospectively examined. Dermatologic data for these patients were assessed. The most frequent clinical manifestation of tularemia was the glandular form (49.7%), followed by the oropharyngeal, ulceroglandular, and oculoglandular forms (39.1, 6.0, and 5.3%, respectively). Physical manifestations were observed in 64.5% of females and 56.9% of males. Lymphadenopathy and tonsillitis were the most frequent physical findings and were noted in 57.6 and 25.2% of patients, respectively. Erythema multiforme was found in 17 patients (11.3%), most of whom presented with the oropharyngeal and glandular forms, and was followed by ulcer (6.0%), urticaria (3.3%), erythema nodosum (2.6%), and cellulitis (0.7%). However, it should be noted that this study was retrospective and that its patient sample demonstrated four of the six clinical forms of tularemia. Patients with the oropharyngeal form of tularemia had statistically significantly more physical findings than those with other clinical forms of the disease (P < 0.001). There were statistically more skin findings in the ulceroglandular form (P < 0.001). There was no statistical correlation between serum antibody titers and cutaneous findings (P = 0.585). Although the literature reports that skin lesions are observed more frequently in women than in men, we did not find any statistically significant difference between the sexes in any type of skin lesion. © 2014 The International Society of Dermatology.
Weather and childbirth: a further search for relationships.
Driscoll, D M
1995-03-01
Previous attempts to find relationships between weather and parturition (childbirth) and its onset (the beginning of labor pains) have revealed, firstly, limited but statistically significant relationships between weather conditions much colder than the day before, with high winds and low pressure, and increased onsets; and secondly, increased numbers of childbirths during periods of atmospheric pressure rise (highly statistically significant). To test these findings, this study examined weather data coincident childbirth data from a hospital at Bryan-College Station, Texas (for a period of 30 cool months from 1987 to 1992). Tests for (1) days of cold fronts, (2) a day before and a day after the cold front, (3) days with large temperature increases, and (4) decreases from the day before revealed no relationship with mean daily rate of onset. Cold days with high winds and low pressure had significantly fewer onsets, a result that is the opposite of previous findings. The postulated relationship between periods of pressure rise and increased birth frequency was negative, i.e., significantly fewer births occurred at those times--again, the opposite of the apparent occurrence in an earlier study. The coincidence of diurnal variations in both atmospheric pressure and frequency of childbirths, was shown to account for fairly strong negative associations between the two variables.(ABSTRACT TRUNCATED AT 250 WORDS)
Biomarker selection for medical diagnosis using the partial area under the ROC curve
2014-01-01
Background A biomarker is usually used as a diagnostic or assessment tool in medical research. Finding an ideal biomarker is not easy and combining multiple biomarkers provides a promising alternative. Moreover, some biomarkers based on the optimal linear combination do not have enough discriminatory power. As a result, the aim of this study was to find the significant biomarkers based on the optimal linear combination maximizing the pAUC for assessment of the biomarkers. Methods Under the binormality assumption we obtain the optimal linear combination of biomarkers maximizing the partial area under the receiver operating characteristic curve (pAUC). Related statistical tests are developed for assessment of a biomarker set and of an individual biomarker. Stepwise biomarker selections are introduced to identify those biomarkers of statistical significance. Results The results of simulation study and three real examples, Duchenne Muscular Dystrophy disease, heart disease, and breast tissue example are used to show that our methods are most suitable biomarker selection for the data sets of a moderate number of biomarkers. Conclusions Our proposed biomarker selection approaches can be used to find the significant biomarkers based on hypothesis testing. PMID:24410929
The statistical average of optical properties for alumina particle cluster in aircraft plume
NASA Astrophysics Data System (ADS)
Li, Jingying; Bai, Lu; Wu, Zhensen; Guo, Lixin
2018-04-01
We establish a model for lognormal distribution of monomer radius and number of alumina particle clusters in plume. According to the Multi-Sphere T Matrix (MSTM) theory, we provide a method for finding the statistical average of optical properties for alumina particle clusters in plume, analyze the effect of different distributions and different detection wavelengths on the statistical average of optical properties for alumina particle cluster, and compare the statistical average optical properties under the alumina particle cluster model established in this study and those under three simplified alumina particle models. The calculation results show that the monomer number of alumina particle cluster and its size distribution have a considerable effect on its statistical average optical properties. The statistical average of optical properties for alumina particle cluster at common detection wavelengths exhibit obvious differences, whose differences have a great effect on modeling IR and UV radiation properties of plume. Compared with the three simplified models, the alumina particle cluster model herein features both higher extinction and scattering efficiencies. Therefore, we may find that an accurate description of the scattering properties of alumina particles in aircraft plume is of great significance in the study of plume radiation properties.
Coping styles and its association with sources of stress in undergraduate medical students.
Cherkil, Sandhya; Gardens, Seby J; Soman, Deepak Kuttikatt
2013-10-01
The two ubiquitous factors that have been identified in medical courses to underlie mental health are stress and different coping styles adopted to combat stress. To find the association between coping styles and stress in undergraduate medical students. A medical college in Central Kerala. A cross-sectional study design was adopted. Source and Severity of Stress Scale, Medical Student Version, was used to assess the source and nature of stress. Brief Cope was used to find out the coping styles adopted. The statistical analysis was done using Statistical Package for Social Sciences version 20 and SAS. Chi-square analysis was used to find the association between coping styles and stress domains and with the overall stress score. There is a significant positive association between overall stress score and coping styles (P=0.001) of 'Negative cope', 'Blame', and 'Humor'. 'Positive cope' and 'Religion' has significant positive association with 'Academics' (P=0.047) and 'self Expectations' (P=0.009). 'Blame' (P<0.001) has very high significant positive association with 'Academics', 'self expectation', and 'Relationships'. Very high significant positive association is further found between 'Humor' (P<0.001) and 'self expectations', 'Living conditions', and 'Health and Value conflict'. 'substance Use' is positively associated in high significance to 'Health and Value conflict' (P<0.001). The outcome of the study emphasizes the need for stress management techniques in the medical school.
The American Arts Industry: Size and Significance.
ERIC Educational Resources Information Center
Chartrand, Harry Hillman
In this study, the U.S. arts industry is conceptually defined and measured with respect to statistical size. The contribution and significance of the arts industry to the economy is then assessed within the context of national competitiveness and the emerging knowledge economy. Study findings indicate that the arts industry contributes between 5%…
Badenes-Ribera, Laura; Frias-Navarro, Dolores; Pascual-Soler, Marcos; Monterde-I-Bort, Héctor
2016-11-01
The statistical reform movement and the American Psychological Association (APA) defend the use of estimators of the effect size and its confidence intervals, as well as the interpretation of the clinical significance of the findings. A survey was conducted in which academic psychologists were asked about their behavior in designing and carrying out their studies. The sample was composed of 472 participants (45.8% men). The mean number of years as a university professor was 13.56 years (SD= 9.27). The use of effect-size estimators is becoming generalized, as well as the consideration of meta-analytic studies. However, several inadequate practices still persist. A traditional model of methodological behavior based on statistical significance tests is maintained, based on the predominance of Cohen’s d and the unadjusted R2/η2, which are not immune to outliers or departure from normality and the violations of statistical assumptions, and the under-reporting of confidence intervals of effect-size statistics. The paper concludes with recommendations for improving statistical practice.
Insignificant solar-terrestrial triggering of earthquakes
Love, Jeffrey J.; Thomas, Jeremy N.
2013-01-01
We examine the claim that solar-terrestrial interaction, as measured by sunspots, solar wind velocity, and geomagnetic activity, might play a role in triggering earthquakes. We count the number of earthquakes having magnitudes that exceed chosen thresholds in calendar years, months, and days, and we order these counts by the corresponding rank of annual, monthly, and daily averages of the solar-terrestrial variables. We measure the statistical significance of the difference between the earthquake-number distributions below and above the median of the solar-terrestrial averages by χ2 and Student's t tests. Across a range of earthquake magnitude thresholds, we find no consistent and statistically significant distributional differences. We also introduce time lags between the solar-terrestrial variables and the number of earthquakes, but again no statistically significant distributional difference is found. We cannot reject the null hypothesis of no solar-terrestrial triggering of earthquakes.
NASA Astrophysics Data System (ADS)
Sinha, Manodeep; Berlind, Andreas A.; McBride, Cameron K.; Scoccimarro, Roman; Piscionere, Jennifer A.; Wibking, Benjamin D.
2018-07-01
Interpreting the small-scale clustering of galaxies with halo models can elucidate the connection between galaxies and dark matter haloes. Unfortunately, the modelling is typically not sufficiently accurate for ruling out models statistically. It is thus difficult to use the information encoded in small scales to test cosmological models or probe subtle features of the galaxy-halo connection. In this paper, we attempt to push halo modelling into the `accurate' regime with a fully numerical mock-based methodology and careful treatment of statistical and systematic errors. With our forward-modelling approach, we can incorporate clustering statistics beyond the traditional two-point statistics. We use this modelling methodology to test the standard Λ cold dark matter (ΛCDM) + halo model against the clustering of Sloan Digital Sky Survey (SDSS) seventh data release (DR7) galaxies. Specifically, we use the projected correlation function, group multiplicity function, and galaxy number density as constraints. We find that while the model fits each statistic separately, it struggles to fit them simultaneously. Adding group statistics leads to a more stringent test of the model and significantly tighter constraints on model parameters. We explore the impact of varying the adopted halo definition and cosmological model and find that changing the cosmology makes a significant difference. The most successful model we tried (Planck cosmology with Mvir haloes) matches the clustering of low-luminosity galaxies, but exhibits a 2.3σ tension with the clustering of luminous galaxies, thus providing evidence that the `standard' halo model needs to be extended. This work opens the door to adding interesting freedom to the halo model and including additional clustering statistics as constraints.
Variations in Eyeball Diameters of the Healthy Adults
Bekerman, Inessa; Gottlieb, Paul
2014-01-01
The purpose of the current research was to reevaluate the normative data on the eyeball diameters. Methods. In a prospective cohort study, the CT data of consecutive 250 adults with healthy eyes were collected and analyzed, and sagittal, transverse, and axial diameters of both eyeballs were measured. The data obtained from the left eye and from the right eye were compared. The correlation analysis was performed with the following variables: orbit size, gender, age, and ethnic background. Results. We did not find statistically significant differences correlated with gender of the patients and their age. The right eyeball was slightly smaller than the left one but this difference was statistically insignificant (P = 0.17). We did not find statistically significant differences of the eyeball sizes among the ethnicities we dealt with. Strong correlation was found between the transverse diameter and the width of the orbit (r = 0.88). Conclusion. The size of a human adult eye is approximately 24.2 mm (transverse) × 23.7 mm (sagittal) × 22.0–24.8 mm (axial) with no significant difference between sexes and age groups. In the transverse diameter, the eyeball size may vary from 21 mm to 27 mm. These data might be useful in ophthalmological, oculoplastic, and neurological practice. PMID:25431659
Variations in eyeball diameters of the healthy adults.
Bekerman, Inessa; Gottlieb, Paul; Vaiman, Michael
2014-01-01
The purpose of the current research was to reevaluate the normative data on the eyeball diameters. Methods. In a prospective cohort study, the CT data of consecutive 250 adults with healthy eyes were collected and analyzed, and sagittal, transverse, and axial diameters of both eyeballs were measured. The data obtained from the left eye and from the right eye were compared. The correlation analysis was performed with the following variables: orbit size, gender, age, and ethnic background. Results. We did not find statistically significant differences correlated with gender of the patients and their age. The right eyeball was slightly smaller than the left one but this difference was statistically insignificant (P = 0.17). We did not find statistically significant differences of the eyeball sizes among the ethnicities we dealt with. Strong correlation was found between the transverse diameter and the width of the orbit (r = 0.88). Conclusion. The size of a human adult eye is approximately 24.2 mm (transverse) × 23.7 mm (sagittal) × 22.0-24.8 mm (axial) with no significant difference between sexes and age groups. In the transverse diameter, the eyeball size may vary from 21 mm to 27 mm. These data might be useful in ophthalmological, oculoplastic, and neurological practice.
Mariani, Bette
2012-01-01
Mentoring is important in the career development of novice and experienced nurses. With the anticipated shortage in nursing, it is important to explore factors such as mentoring that may contribute to career satisfaction and intent to stay in the profession. This study explored the effects of mentoring on career satisfaction and intent to stay in nursing, and the relationship between career satisfaction and intent to stay in nursing. It was conducted through a mailed survey of RNs 55 years or younger currently in practice, education, administration, or research. Career satisfaction was measured through the use of the newly developed Mariani Nursing Career Satisfaction Scale. Findings revealed no statistically significant effect of mentoring on career satisfaction and intent to stay in nursing. There was a statistically significant relationship between career satisfaction and intent to stay in nursing. The majority of nurses reported participating in a mentoring relationship. Although the findings related to mentoring, career satisfaction, and intent to stay were not statistically significant, there was a prevalence of mentoring in nursing, thus suggesting the need for future research to identify outcomes of mentoring. In addition, the study contributed a newly developed instrument to measure the concept of career satisfaction in nursing.
Mariani, Bette
2012-01-01
Mentoring is important in the career development of novice and experienced nurses. With the anticipated shortage in nursing, it is important to explore factors such as mentoring that may contribute to career satisfaction and intent to stay in the profession. This study explored the effects of mentoring on career satisfaction and intent to stay in nursing, and the relationship between career satisfaction and intent to stay in nursing. It was conducted through a mailed survey of RNs 55 years or younger currently in practice, education, administration, or research. Career satisfaction was measured through the use of the newly developed Mariani Nursing Career Satisfaction Scale. Findings revealed no statistically significant effect of mentoring on career satisfaction and intent to stay in nursing. There was a statistically significant relationship between career satisfaction and intent to stay in nursing. The majority of nurses reported participating in a mentoring relationship. Although the findings related to mentoring, career satisfaction, and intent to stay were not statistically significant, there was a prevalence of mentoring in nursing, thus suggesting the need for future research to identify outcomes of mentoring. In addition, the study contributed a newly developed instrument to measure the concept of career satisfaction in nursing. PMID:22645673
Outlier Removal and the Relation with Reporting Errors and Quality of Psychological Research
Bakker, Marjan; Wicherts, Jelte M.
2014-01-01
Background The removal of outliers to acquire a significant result is a questionable research practice that appears to be commonly used in psychology. In this study, we investigated whether the removal of outliers in psychology papers is related to weaker evidence (against the null hypothesis of no effect), a higher prevalence of reporting errors, and smaller sample sizes in these papers compared to papers in the same journals that did not report the exclusion of outliers from the analyses. Methods and Findings We retrieved a total of 2667 statistical results of null hypothesis significance tests from 153 articles in main psychology journals, and compared results from articles in which outliers were removed (N = 92) with results from articles that reported no exclusion of outliers (N = 61). We preregistered our hypotheses and methods and analyzed the data at the level of articles. Results show no significant difference between the two types of articles in median p value, sample sizes, or prevalence of all reporting errors, large reporting errors, and reporting errors that concerned the statistical significance. However, we did find a discrepancy between the reported degrees of freedom of t tests and the reported sample size in 41% of articles that did not report removal of any data values. This suggests common failure to report data exclusions (or missingness) in psychological articles. Conclusions We failed to find that the removal of outliers from the analysis in psychological articles was related to weaker evidence (against the null hypothesis of no effect), sample size, or the prevalence of errors. However, our control sample might be contaminated due to nondisclosure of excluded values in articles that did not report exclusion of outliers. Results therefore highlight the importance of more transparent reporting of statistical analyses. PMID:25072606
Maldonado, Alejandra; Laugisch, Oliver; Bürgin, Walter; Sculean, Anton; Eick, Sigrun
2018-06-22
Considering the increasing number of elderly people, dementia has gained an important role in today's society. Although the contributing factors for dementia have not been fully understood, chronic periodontitis (CP) seems to have a possible link to dementia. To conduct a systematic review including meta-analysis in order to assess potential differences in clinical periodontal variables between patients with dementia and non-demented individuals. The following focused question was evaluated: is periodontitis associated with dementia? Electronic searches in two databases, MEDLINE and EMBASE, were conducted. Meta-analysis was performed with the collected data in order to find a statistically significant difference in clinical periodontal variables between the group of dementia and the cognitive normal controls. Forty-two articles remained for full text reading. Finally, seven articles met the inclusion criteria and only five studies provided data suitable for meta-analysis. Periodontal probing depth (PPD), bleeding on probing (BOP), gingival bleeding index (GBI), clinical attachment level (CAL), and plaque index (PI) were included as periodontal variables in the meta-analysis. Each variable revealed a statistically significant difference between the groups. In an attempt to reveal an overall difference between the periodontal variables in dementia patients and non-demented individuals, the chosen variables were transformed into units that resulted in a statistically significant overall difference (p < 0.00001). The current findings indicate that compared to systemically healthy individuals, demented patients show significantly worse clinical periodontal variables. However, further epidemiological studies including a high numbers of participants, the use of exact definitions both for dementia and chronic periodontitis and adjusted for cofounders is warranted. These findings appear to support the putative link between CP and dementia. Consequently, the need for periodontal screening and treatment of elderly demented people should be emphasized.
Affinity-seeking, social loneliness, and social avoidance among Facebook users.
Lemieux, Robert; Lajoie, Sean; Trainor, Nathan E
2013-04-01
This study explored the relations between use of the social networking site Facebook and scores on affinity-seeking, social loneliness, and social avoidance by 313 college students. Social loneliness and social avoidance, but not affinity-seeking, were positively and statistically significantly related to time spent using Facebook. The number of close Facebook friends was negatively and statistically significantly related to social loneliness and social avoidance. Women perceived Facebook as a more integral part of daily interactions than did men. 38% of the 283 Facebook members indicated their accounts contained information and/or a picture that could embarrass them, with men having significantly more embarrassing content than women. The findings are discussed within the context of social compensation.
Gaus, Wilhelm
2014-09-02
The US National Toxicology Program (NTP) is assessed by a statistician. In the NTP-program groups of rodents are fed for a certain period of time with different doses of the substance that is being investigated. Then the animals are sacrificed and all organs are examined pathologically. Such an investigation facilitates many statistical tests. Technical Report TR 578 on Ginkgo biloba is used as an example. More than 4800 statistical tests are possible with the investigations performed. Due to a thought experiment we expect >240 false significant tests. In actuality, 209 significant pathological findings were reported. The readers of Toxicology Letters should carefully distinguish between confirmative and explorative statistics. A confirmative interpretation of a significant test rejects the null-hypothesis and delivers "statistical proof". It is only allowed if (i) a precise hypothesis was established independently from the data used for the test and (ii) the computed p-values are adjusted for multiple testing if more than one test was performed. Otherwise an explorative interpretation generates a hypothesis. We conclude that NTP-reports - including TR 578 on Ginkgo biloba - deliver explorative statistics, i.e. they generate hypotheses, but do not prove them. Copyright © 2014 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.
Invited Commentary: Can Issues With Reproducibility in Science Be Blamed on Hypothesis Testing?
Weinberg, Clarice R
2017-09-15
In the accompanying article (Am J Epidemiol. 2017;186(6):646-647), Dr. Timothy Lash makes a forceful case that the problems with reproducibility in science stem from our "culture" of null hypothesis significance testing. He notes that when attention is selectively given to statistically significant findings, the estimated effects will be systematically biased away from the null. Here I revisit the recent history of genetic epidemiology and argue for retaining statistical testing as an important part of the tool kit. Particularly when many factors are considered in an agnostic way, in what Lash calls "innovative" research, investigators need a selection strategy to identify which findings are most likely to be genuine, and hence worthy of further study. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.
NASA Astrophysics Data System (ADS)
Liao, Yuqi
The utility patent, as a legal record of invention, is widely believed to be a close proxy for innovation among firms, industries, and economies as a whole. One of the critical drivers of patenting -- and ultimately, innovation -- is education. The science, technology, engineering and math (STEM) fields in education are of special importance. There is, however, little empirical research to substantiate a connection between STEM education and innovation outcomes. Seeking to fill this gap, this paper finds that, in general, there is no evidence of a meaningful relationship between STEM educational attainment and utility patent conferrals. The relationship of interest, though generally not statistically significant, is stronger for temporary US visa holders than for US citizens or permanent US residents. However, I find a large and statistically significant association between STEM educational attainment and utility patent conferrals for states that have above-average college educational attainment or above-average advanced industries workforce concentration.
Rainfall statistics, stationarity, and climate change.
Sun, Fubao; Roderick, Michael L; Farquhar, Graham D
2018-03-06
There is a growing research interest in the detection of changes in hydrologic and climatic time series. Stationarity can be assessed using the autocorrelation function, but this is not yet common practice in hydrology and climate. Here, we use a global land-based gridded annual precipitation (hereafter P ) database (1940-2009) and find that the lag 1 autocorrelation coefficient is statistically significant at around 14% of the global land surface, implying nonstationary behavior (90% confidence). In contrast, around 76% of the global land surface shows little or no change, implying stationary behavior. We use these results to assess change in the observed P over the most recent decade of the database. We find that the changes for most (84%) grid boxes are within the plausible bounds of no significant change at the 90% CI. The results emphasize the importance of adequately accounting for natural variability when assessing change. Copyright © 2018 the Author(s). Published by PNAS.
Rainfall statistics, stationarity, and climate change
NASA Astrophysics Data System (ADS)
Sun, Fubao; Roderick, Michael L.; Farquhar, Graham D.
2018-03-01
There is a growing research interest in the detection of changes in hydrologic and climatic time series. Stationarity can be assessed using the autocorrelation function, but this is not yet common practice in hydrology and climate. Here, we use a global land-based gridded annual precipitation (hereafter P) database (1940–2009) and find that the lag 1 autocorrelation coefficient is statistically significant at around 14% of the global land surface, implying nonstationary behavior (90% confidence). In contrast, around 76% of the global land surface shows little or no change, implying stationary behavior. We use these results to assess change in the observed P over the most recent decade of the database. We find that the changes for most (84%) grid boxes are within the plausible bounds of no significant change at the 90% CI. The results emphasize the importance of adequately accounting for natural variability when assessing change.
NASA Astrophysics Data System (ADS)
Bachiller, Alejandro; Poza, Jesús; Gómez, Carlos; Molina, Vicente; Suazo, Vanessa; Hornero, Roberto
2015-02-01
Objective. The aim of this research is to explore the coupling patterns of brain dynamics during an auditory oddball task in schizophrenia (SCH). Approach. Event-related electroencephalographic (ERP) activity was recorded from 20 SCH patients and 20 healthy controls. The coupling changes between auditory response and pre-stimulus baseline were calculated in conventional EEG frequency bands (theta, alpha, beta-1, beta-2 and gamma), using three coupling measures: coherence, phase-locking value and Euclidean distance. Main results. Our results showed a statistically significant increase from baseline to response in theta coupling and a statistically significant decrease in beta-2 coupling in controls. No statistically significant changes were observed in SCH patients. Significance. Our findings support the aberrant salience hypothesis, since SCH patients failed to change their coupling dynamics between stimulus response and baseline when performing an auditory cognitive task. This result may reflect an impaired communication among neural areas, which may be related to abnormal cognitive functions.
Adolescent cigarette smoking and health risk behavior.
Busen, N H; Modeland, V; Kouzekanani, K
2001-06-01
During the past 30 years, tobacco use among adolescents has substantially increased, resulting in major health problems associated with tobacco consumption. The purpose of this study was to identify adolescent smoking behaviors and to determine the relationship among smoking, specific demographic variables, and health risk behaviors. The sample consisted of 93 self-selecting adolescents. An ex post facto design was used for this study and data were analyzed by using nonparametric statistics. Findings included a statistically significant relationship between lifetime cigarette use and ethnicity. Statistically significant relationships were also found among current cigarette use and ethnicity, alcohol use, marijuana use, suicidal thoughts, and age at first sexual intercourse. Nurses and other providers must recognize that cigarette smoking may indicate other risk behaviors common among adolescents. Copyright 2001 by W.B. Saunders Company
The Influence of Host Galaxies in Type Ia Supernova Cosmology
DOE Office of Scientific and Technical Information (OSTI.GOV)
Uddin, Syed A.; Mould, Jeremy; Lidman, Chris
We use a sample of 1338 spectroscopically confirmed and photometrically classified Type Ia supernovae (SNe Ia) sourced from Carnegie Supernova Project, Center for Astrophysics Supernova Survey, Sloan Digital Sky Survey-II, and SuperNova Legacy Survey SN samples to examine the relationships between SNe Ia and the galaxies that host them. Our results provide confirmation with improved statistical significance that SNe Ia, after standardization, are on average more luminous in massive hosts (significance >5 σ ), and decline more rapidly in massive hosts (significance >9 σ ) and in hosts with low specific star formation rates (significance >8 σ ). We studymore » the variation of these relationships with redshift and detect no evolution. We split SNe Ia into pairs of subsets that are based on the properties of the hosts and fit cosmological models to each subset. Including both systematic and statistical uncertainties, we do not find any significant shift in the best-fit cosmological parameters between the subsets. Among different SN Ia subsets, we find that SNe Ia in hosts with high specific star formation rates have the least intrinsic scatter ( σ {sub int} = 0.08 ± 0.01) in luminosity after standardization.« less
The Influence of Host Galaxies in Type Ia Supernova Cosmology
NASA Astrophysics Data System (ADS)
Uddin, Syed A.; Mould, Jeremy; Lidman, Chris; Ruhlmann-Kleider, Vanina; Zhang, Bonnie R.
2017-10-01
We use a sample of 1338 spectroscopically confirmed and photometrically classified Type Ia supernovae (SNe Ia) sourced from Carnegie Supernova Project, Center for Astrophysics Supernova Survey, Sloan Digital Sky Survey-II, and SuperNova Legacy Survey SN samples to examine the relationships between SNe Ia and the galaxies that host them. Our results provide confirmation with improved statistical significance that SNe Ia, after standardization, are on average more luminous in massive hosts (significance >5σ), and decline more rapidly in massive hosts (significance >9σ) and in hosts with low specific star formation rates (significance >8σ). We study the variation of these relationships with redshift and detect no evolution. We split SNe Ia into pairs of subsets that are based on the properties of the hosts and fit cosmological models to each subset. Including both systematic and statistical uncertainties, we do not find any significant shift in the best-fit cosmological parameters between the subsets. Among different SN Ia subsets, we find that SNe Ia in hosts with high specific star formation rates have the least intrinsic scatter (σ int = 0.08 ± 0.01) in luminosity after standardization.
A Population Study of Gaseous Exoplanets
NASA Astrophysics Data System (ADS)
Tsiaras, A.; Waldmann, I. P.; Zingales, T.; Rocchetto, M.; Morello, G.; Damiano, M.; Karpouzas, K.; Tinetti, G.; McKemmish, L. K.; Tennyson, J.; Yurchenko, S. N.
2018-04-01
We present here the analysis of 30 gaseous extrasolar planets, with temperatures between 600 and 2400 K and radii between 0.35 and 1.9 R Jup. The quality of the HST/WFC3 spatially scanned data combined with our specialized analysis tools allow us to study the largest and most self-consistent sample of exoplanetary transmission spectra to date and examine the collective behavior of warm and hot gaseous planets rather than isolated case studies. We define a new metric, the Atmospheric Detectability Index (ADI) to evaluate the statistical significance of an atmospheric detection and find statistically significant atmospheres in around 16 planets out of the 30 analyzed. For most of the Jupiters in our sample, we find the detectability of their atmospheres to be dependent on the planetary radius but not on the planetary mass. This indicates that planetary gravity plays a secondary role in the state of gaseous planetary atmospheres. We detect the presence of water vapour in all of the statistically detectable atmospheres, and we cannot rule out its presence in the atmospheres of the others. In addition, TiO and/or VO signatures are detected with 4σ confidence in WASP-76 b, and they are most likely present in WASP-121 b. We find no correlation between expected signal-to-noise and atmospheric detectability for most targets. This has important implications for future large-scale surveys.
Taljanovic, Mihra S; Graham, Anna R; Benjamin, James B; Gmitro, Arthur F; Krupinski, Elizabeth A; Schwartz, Stephanie A; Hunter, Tim B; Resnick, Donald L
2008-05-01
To correlate the amount of bone marrow edema (BME) calculated by magnetic resonance imaging(MRI) with clinical findings, histopathology, and radiographic findings, in patients with advanced hip osteoarthritis(OA). The study was approved by The Institutional Human Subject Protection Committee. Coronal MRI of hips was acquired in 19 patients who underwent hip replacement. A spin echo (SE) sequence with four echoes and separate fast spin echo (FSE) proton density (PD)-weighted SE sequences of fat (F) and water (W) were acquired with water and fat suppression, respectively. T2 and water:fat ratio calculations were made for the outlined regions of interest. The calculated MRI values were correlated with the clinical, radiographic, and histopathologic findings. Analyses of variance were done on the MRI data for W/(W + F) and for T2 values (total and focal values) for the symptomatic and contralateral hips. The values were significantly higher in the study group. Statistically significant correlations were found between pain and total W/(W + F), pain and focal T2 values, and the number of microfractures and calculated BME for the focal W/(W + F) in the proximal femora. Statistically significant correlations were found between the radiographic findings and MRI values for total W/(W + F), focal W/(W + F) and focal T2 and among the radiographic findings, pain, and hip movement. On histopathology, only a small amount of BME was seen in eight proximal femora. The amount of BME in the OA hip, as measured by MRI, correlates with the severity of pain, radiographic findings, and number of microfractures.
Linardon, Jake; de la Piedad Garcia, Xochitl; Brennan, Leah
2017-01-01
This systematic review synthesised the literature on predictors, moderators, and mediators of outcome following Fairburn's CBT for eating disorders. Sixty-five articles were included. The relationship between individual variables and outcome was synthesised separately across diagnoses and treatment format. Early change was found to be a consistent mediator of better outcomes across all eating disorders. Moderators were mostly tested in binge eating disorder, and most moderators did not affect cognitive-behavioural treatment outcome relative to other treatments. No consistent predictors emerged. Findings suggest that it is unclear how and for whom this treatment works. More research testing mediators and moderators is needed, and variables selected for analyses need to be empirically and theoretically driven. Future recommendations include the need for authors to (i) interpret the clinical and statistical significance of findings; (ii) use a consistent definition of outcome so that studies can be directly compared; and (iii) report null and statistically significant findings. Copyright © 2016 John Wiley & Sons, Ltd and Eating Disorders Association. © 2016 John Wiley & Sons, Ltd and Eating Disorders Association.
Petrović, Kosta; Turkalj, Ivan; Stojanović, Sanja; Vucaj-Cirilović, Viktorija; Nikolić, Olivera; Stojiljković, Dragana
2013-08-01
Computerized tomography (CT), especially multidetector CT (MDCT), has had a revolutionary impact in diagnostic in traumatized patients. The aim of the study was to identify and compare the frequency of injuries to bone structures of the thorax displayed with 5-mm-thick axial CT slices and thin-slice (MDCT) examination with the use of 3D reconstructions, primarily multiplanar reformations (MPR). This prospective study included 61 patients with blunt trauma submitted to CT scan of the thorax as initial assessment. The two experienced radiologists inde pendently and separately described the findings for 5-mm-thick axial CT slices (5 mm CT) as in monoslice CT examination; MPR and other 3D reconstructions along with thin-slice axial sections which were available in modern MDCT technologies. After describing thin-slice examination in case of disagreement in the findings, the examiners redescribed thin-slice examination together which was ultimately considered as a real, true finding. No statistically significant difference in interobserver evaluation of 5 mm CT examination was recorded (p > 0.05). Evaluation of fractures of sternum with 5 mm CT and MDCT showed a statistically significant difference (p < 0.05) in favor of better display of injury by MDCT examination. MDCT is a powerful diagnostic tool that can describe higher number of bone fractures of the chest in traumatized patients compared to 5 mm CT, especially in the region of sternum for which a statistical significance was obtained using MPR. Moreover, the importance of MDCT is also set by easier and more accurate determination of the level of bone injury.
Impact of statin adherence on cardiovascular disease and mortality outcomes: a systematic review
De Vera, Mary A; Bhole, Vidula; Burns, Lindsay C; Lacaille, Diane
2014-01-01
Aims While suboptimal adherence to statin medication has been quantified in real-world patient settings, a better understanding of its impact is needed, particularly with respect to distinct problems of medication taking. Our aim was to synthesize current evidence on the impacts of statin adherence, discontinuation and persistence on cardiovascular disease and mortality outcomes. Methods We conducted a systematic review of peer-reviewed studies using a mapped search of Medline, Embase and International Pharmaceutical Abstracts databases. Observational studies that met the following criteria were included: defined patient population; statin adherence exposure; defined study outcome [i.e. cardiovascular disease (CVD), mortality]; and reporting of statin-specific results. Results Overall, 28 studies were included, with 19 studies evaluating outcomes associated with statin adherence, six with statin discontinuation and three with statin persistence. Among adherence studies, the proportion of days covered was the most widely used measure, with the majority of studies reporting increased risk of CVD (statistically significant risk estimates ranging from 1.22 to 5.26) and mortality (statistically significant risk estimates ranging from 1.25 to 2.54) among non-adherent individuals. There was greater methodological variability in discontinuation and persistence studies. However, findings of increased CVD (statistically significant risk estimates ranging from 1.22 to 1.67) and mortality (statistically significant risk estimates ranging from 1.79 to 5.00) among nonpersistent individuals were also consistently reported. Conclusions Observational studies consistently report an increased risk of adverse outcomes associated with poor statin adherence. These findings have important implications for patients and physicians and emphasize the importance of monitoring and encouraging adherence to statin therapy. PMID:25364801
Teenage pregnancy and mental health beyond the postpartum period: a systematic review.
Xavier, Chloé; Benoit, Anita; Brown, Hilary K
2018-06-01
Teenage mothers are at increased risk for adverse social outcomes and short-term health problems, but long-term impacts on mental health are poorly understood. The aims of our systematic review were to determine the association between teenage pregnancy and mental health beyond the postpartum period, critically appraise the literature's quality and guide future research. We systematically searched MEDLINE, Embase, PsycINFO, CINAHL, Scopus and Web of Science from inception to June 2017 for peer-reviewed articles written in English or French. Data were collected using a modified Cochrane Data Extraction Form. Study quality was assessed using the Effective Public Health Practice Project critical appraisal tool. Heterogeneity of studies permitted only a qualitative synthesis. Nine quantitative studies comprising the results from analyses of 11 cohorts met our criteria and were rated as strong (n=5), moderate (n=2) or weak (n=2). Three cohorts found a statistically significant association between teenage pregnancy and poor long-term mental health after adjustment, three found a statistically significant association before but not after adjustment and five did not find a statistically significant association. Studies observed varying degrees of attenuation after considering social context. Studies with statistically significant findings tended to comprise earlier cohorts, with outcomes measured at older ages. The association between teenage pregnancy and mental health beyond the postpartum period remains unclear. Future studies should employ age-period-cohort frameworks to disentangle effects of normative patterns and stress accumulation. Social factors are important in determining long-term mental health of teenage mothers and should be prioritised in prevention and intervention strategies. © 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.
Cardoso-Silva, Cristina; Barbería, Elena; Maroto, Myriam; García-Godoy, Franklin
2011-02-01
The aim of the present study was to conduct a clinical and radiographic long-term evaluation of pulpotomy in temporary molars performed with Grey and White Mineral Trioxide Aggregate (MTA) and compare the results of Grey and White MTA pulpotomies in a sample of 233 primary molars with a maximum follow-up period of 84 months. The sample was selected from patients treated at the Department of Pediatric Dentistry, Faculty of Dentistry, Complutense University of Madrid, Spain. This prospective study included first and second primary molars treated with pulpotomy with Grey or White MTA, controlled for a maximum follow-up period of 84 months. Statistical analysis of clinical and radiographic findings was completed using ANOVA (P<0.05). Follow-up evaluations, performed every 6 months, revealed that only 2 molars treated with White MTA presented abscess and pathological mobility. Radiographic examination of the 210 molars revealed unfavourable pulp response in only 6 molars (internal or furcation root resorption), without statistically significant differences between Grey and White MTA. Two radiological findings were noticed: dentine bridge formation and partial or total root canal stenosis. Grey MTA induced a higher percentage of dentine bridges with statistically significant differences (P<0.05), and a higher percentage of pulp canal stenosis, without a statistically significant difference. Grey and White MTA presented high levels of clinical and radiographic success. Although the present study showed evidence of a very good biologic response with both types of MTA, Grey MTA showed significantly higher number of dentine bridge formation than White MTA. Copyright © 2010 Elsevier Ltd. All rights reserved.
Mathur, Sunil; Sadana, Ajit
2015-12-01
We present a rank-based test statistic for the identification of differentially expressed genes using a distance measure. The proposed test statistic is highly robust against extreme values and does not assume the distribution of parent population. Simulation studies show that the proposed test is more powerful than some of the commonly used methods, such as paired t-test, Wilcoxon signed rank test, and significance analysis of microarray (SAM) under certain non-normal distributions. The asymptotic distribution of the test statistic, and the p-value function are discussed. The application of proposed method is shown using a real-life data set. © The Author(s) 2011.
NASA Astrophysics Data System (ADS)
Bonneau, Joseph; Just, Mike; Matthews, Greg
We study the efficiency of statistical attacks on human authentication systems relying on personal knowledge questions. We adapt techniques from guessing theory to measure security against a trawling attacker attempting to compromise a large number of strangers' accounts. We then examine a diverse corpus of real-world statistical distributions for likely answer categories such as the names of people, pets, and places and find that personal knowledge questions are significantly less secure than graphical or textual passwords. We also demonstrate that statistics can be used to increase security by proactively shaping the answer distribution to lower the prevalence of common responses.
Musicians' edge: A comparison of auditory processing, cognitive abilities and statistical learning.
Mandikal Vasuki, Pragati Rao; Sharma, Mridula; Demuth, Katherine; Arciuli, Joanne
2016-12-01
It has been hypothesized that musical expertise is associated with enhanced auditory processing and cognitive abilities. Recent research has examined the relationship between musicians' advantage and implicit statistical learning skills. In the present study, we assessed a variety of auditory processing skills, cognitive processing skills, and statistical learning (auditory and visual forms) in age-matched musicians (N = 17) and non-musicians (N = 18). Musicians had significantly better performance than non-musicians on frequency discrimination, and backward digit span. A key finding was that musicians had better auditory, but not visual, statistical learning than non-musicians. Performance on the statistical learning tasks was not correlated with performance on auditory and cognitive measures. Musicians' superior performance on auditory (but not visual) statistical learning suggests that musical expertise is associated with an enhanced ability to detect statistical regularities in auditory stimuli. Copyright © 2016 Elsevier B.V. All rights reserved.
Preuss, Harry G; Kaats, Gilbert R; Mrvichin, Nate; Bagchi, Debasis; Swaroop, Anand
2018-01-01
Previous evaluations in nondiabetic subjects revealed statistically significant correlations between fasting blood glucose (FBG) levels used as an estimate of insulin resistance and many components constituting the metabolic syndrome. Similar significant correlations were not found employing chronological age as the independent variable in the same nondiabetic individuals. The major purpose here was to replicate as well as corroborate the previous cross-sectional observations, emphasizing results obtained from data collected longitudinally. Material was assessed from 99 nondiabetic volunteers who had undergone 2 separate baseline measurements carried out over a minimum of 5 and up to a maximum of 20 years. Findings from the starting baseline measurements mimicked many observations perceived in the earlier published cross-sectional material. The following correlations with elements constituting the metabolic syndrome using FBG as an independent variable were once more statistically significantly positive: scale weight, fat mass, circulating levels of triglycerides and high-sensitivity C-reactive protein (hsCRP). High-density lipoprotein (HDL) cholesterol was once again appropriately significant in a negative direction. In contrast, the same correlations were generally nonsignificant when age replaced FBG as the independent variable. Examining the 2 data sets over the 5-20-year intervals, FBG increased statistically significantly over time. However, the average increase clinically was relatively minor: -92.1 mg/dL ± 1.1 (SEM) vs 95.1 mg/dL ± 1.1 (SEM), p < 0.007. When the actual changes (delta) in the dependent parameters were correlated with the individual passages of time (intervals in years), only downward changes in aspartate aminotransferase (AST) levels were statistically significant. Fat-free mass showed a trend downward, whereas fat mass, trunk fat, and triglycerides merely demonstrated trends upward. Current findings gathered over years are consistent with the original hypothesis that maintaining relatively low, stable circulating glucose levels during aging retards the development and intensity of many common manifestations of the metabolic syndrome.
Sb2Te3 and Its Superlattices: Optimization by Statistical Design.
Behera, Jitendra K; Zhou, Xilin; Ranjan, Alok; Simpson, Robert E
2018-05-02
The objective of this work is to demonstrate the usefulness of fractional factorial design for optimizing the crystal quality of chalcogenide van der Waals (vdW) crystals. We statistically analyze the growth parameters of highly c axis oriented Sb 2 Te 3 crystals and Sb 2 Te 3 -GeTe phase change vdW heterostructured superlattices. The statistical significance of the growth parameters of temperature, pressure, power, buffer materials, and buffer layer thickness was found by fractional factorial design and response surface analysis. Temperature, pressure, power, and their second-order interactions are the major factors that significantly influence the quality of the crystals. Additionally, using tungsten rather than molybdenum as a buffer layer significantly enhances the crystal quality. Fractional factorial design minimizes the number of experiments that are necessary to find the optimal growth conditions, resulting in an order of magnitude improvement in the crystal quality. We highlight that statistical design of experiment methods, which is more commonly used in product design, should be considered more broadly by those designing and optimizing materials.
Plasma Cell Neoplasms (Including Multiple Myeloma)—Health Professional Version
There are several types of plasma cell neoplasms, including monoclonal gammopathy of undetermined significance (MGUS), isolated plasmacytoma of the bone, extramedullary plasmacytoma, and multiple myeloma. Find evidence-based information on plasma cell neoplasms treatment, research, and statistics.
Graham, Daniel J; Field, David J
2008-01-01
Two recent studies suggest that natural scenes and paintings show similar statistical properties. But does the content or region of origin of an artwork affect its statistical properties? We addressed this question by having judges place paintings from a large, diverse collection of paintings into one of three subject-matter categories using a forced-choice paradigm. Basic statistics for images whose caterogization was agreed by all judges showed no significant differences between those judged to be 'landscape' and 'portrait/still-life', but these two classes differed from paintings judged to be 'abstract'. All categories showed basic spatial statistical regularities similar to those typical of natural scenes. A test of the full painting collection (140 images) with respect to the works' place of origin (provenance) showed significant differences between Eastern works and Western ones, differences which we find are likely related to the materials and the choice of background color. Although artists deviate slightly from reproducing natural statistics in abstract art (compared to representational art), the great majority of human art likely shares basic statistical limitations. We argue that statistical regularities in art are rooted in the need to make art visible to the eye, not in the inherent aesthetic value of natural-scene statistics, and we suggest that variability in spatial statistics may be generally imposed by manufacture.
The effects of common risk factors on stock returns: A detrended cross-correlation analysis
NASA Astrophysics Data System (ADS)
Ruan, Qingsong; Yang, Bingchan
2017-10-01
In this paper, we investigate the cross-correlations between Fama and French three factors and the return of American industries on the basis of cross-correlation statistic test and multifractal detrended cross-correlation analysis (MF-DCCA). Qualitatively, we find that the return series of Fama and French three factors and American industries were overall significantly cross-correlated based on the analysis of a statistic. Quantitatively, we find that the cross-correlations between three factors and the return of American industries were strongly multifractal, and applying MF-DCCA we also investigate the cross-correlation of industry returns and residuals. We find that there exists multifractality of industry returns and residuals. The result of correlation coefficients we can verify that there exist other factors which influence the industry returns except Fama three factors.
EEG-LORETA endophenotypes of the common idiopathic generalized epilepsy syndromes.
Clemens, B; Puskás, S; Besenyei, M; Emri, M; Opposits, G; Kis, S A; Hollódy, K; Fogarasi, A; Kondákor, I; Füle, K; Bense, K; Fekete, I
2012-05-01
We tested the hypothesis that the cortical areas with abnormal local EEG synchronization are dissimilar in the three common idiopathic generalized epilepsy (IGE) phenotypes: IGE patients with absence seizures (ABS), juvenile myoclonic epilepsy (JME) and epilepsy with generalized tonic-clonic seizures exclusively (EGTCS). Groups of unmedicated ABS, JME and EGTCS patients were investigated. Waking EEG background activity (without any epileptiform potentials) was analyzed by a source localization method, LORETA (Low Resolution Electromagnetic Tomography). Each patient group was compared to a separate, age-matched group of healthy control persons. Voxel-based, normalized broad-band (delta, theta, alpha, and beta) and very narrow band (VNB, 1Hz bandwidth, from 1 to 25Hz) LORETA activity (=current source density, A/m(2)) were computed for each person. Group comparison included subtraction (average patient data minus average control data) and group statistics (multiple t-tests, where Bonferroni-corrected p<0.05 values were accepted as statistically significant). Statistically not significant main findings were: overall increased delta and theta broad band activity in the ABS and JME groups; decrease of alpha and beta activity in the EGTCS group. Statistically significant main findings were as follows. JME group: bilaterally increased theta activity in posterior (temporal, parietal, and occipital) cortical areas; bilaterally increased activity in the medial and basal prefrontal area in the 8Hz VNB; bilaterally decreased activity in the precuneus, posterior cingulate and superior parietal lobule in the 11Hz and 21-22Hz VNBs. ABS group: bilaterally increased theta activity emerged in the basal prefrontal and medial temporal limbic areas. Decreased activity was found at 19-21Hz in the right postcentral gyrus and parts of the right superior and medial temporal gyri. EGTCS group: decreased activity was found in the frontal cortex and the postcentral gyrus at 10-11Hz, increased activity in the right parahippocampal gyrus at 16-18Hz. Increased theta activity in the posterior parts of the cortex is the endophenotype for JME. Increased theta activity in the fronto-temporal limbic areas is the endophenotype for ABS. Statistically not significant findings might indicate diffuse biochemical abnormality of the cortex in JME and ABS. EEG-LORETA endophenotypes may correspond to the selective propensity to generate absence and myoclonic seizures in the ABS and JME syndromes. Copyright © 2011 Elsevier B.V. All rights reserved.
Paranjpe, Madhav G; Denton, Melissa D; Vidmar, Tom; Elbekai, Reem H
2014-01-01
Carcinogenicity studies have been performed in conventional 2-year rodent studies for at least 3 decades, whereas the short-term carcinogenicity studies in transgenic mice, such as Tg.rasH2, have only been performed over the last decade. In the 2-year conventional rodent studies, interlinked problems, such as increasing trends in the initial body weights, increased body weight gains, high incidence of spontaneous tumors, and low survival, that complicate the interpretation of findings have been well established. However, these end points have not been evaluated in the short-term carcinogenicity studies involving the Tg.rasH2 mice. In this article, we present retrospective analysis of data obtained from control groups in 26-week carcinogenicity studies conducted in Tg.rasH2 mice since 2004. Our analysis showed statistically significant decreasing trends in initial body weights of both sexes. Although the terminal body weights did not show any significant trends, there was a statistically significant increasing trend toward body weight gains, more so in males than in females, which correlated with increasing trends in the food consumption. There were no statistically significant alterations in mortality trends. In addition, the incidence of all common spontaneous tumors remained fairly constant with no statistically significant differences in trends. © The Author(s) 2014.
Morphometric variations of the 7th cervical vertebrae of Zulu, White, and Colored South Africans.
Kibii, Job M; Pan, Rualing; Tobias, Phillip V
2010-05-01
The 7th cervical vertebrae of 240 cadavers of South African Zulu, White, and Colored population groups were examined to determine morphometric variation. White and Colored females had statistically significant narrower cervical anteroposterior diameters than their male counterparts, whereas no statistically significant difference between sexes of the Zulu population group was observed in this variable. In addition, although Zulu and Colored females had statistically significant narrower cervical transverse diameters than their male counterparts, there was no statistically significant variation between South African white males and females in this respect. The findings indicate that sexual dimorphism is more apparent in the vertebral centrum, across the three population groups, where males had significantly larger dimensions in centrum anteroposterior diameter, height, and width than their female counterparts. The study further reveals that sexual dimorphism is more apparent when one compares aspects of the 7th cervical vertebra between sexes within the same population group. Overall, the dimensions of the various variates of the vertebra are substantially smaller in women than in men. The smaller dimensions, particularly of the centrum, may be the result of lower skeletal mass in women and render them more vulnerable to fractures resulting from compression forces. 2010 Wiley-Liss, Inc.
Pingault, Jean Baptiste; Côté, Sylvana M.; Petitclerc, Amélie; Vitaro, Frank; Tremblay, Richard E.
2015-01-01
Background Parental educational expectations have been associated with children’s educational attainment in a number of long-term longitudinal studies, but whether this relationship is causal has long been debated. The aims of this prospective study were twofold: 1) test whether low maternal educational expectations contributed to failure to graduate from high school; and 2) compare the results obtained using different strategies for accounting for confounding variables (i.e. multivariate regression and propensity score matching). Methodology/Principal Findings The study sample included 1,279 participants from the Quebec Longitudinal Study of Kindergarten Children. Maternal educational expectations were assessed when the participants were aged 12 years. High school graduation – measuring educational attainment – was determined through the Quebec Ministry of Education when the participants were aged 22–23 years. Findings show that when using the most common statistical approach (i.e. multivariate regressions to adjust for a restricted set of potential confounders) the contribution of low maternal educational expectations to failure to graduate from high school was statistically significant. However, when using propensity score matching, the contribution of maternal expectations was reduced and remained statistically significant only for males. Conclusions/Significance The results of this study are consistent with the possibility that the contribution of parental expectations to educational attainment is overestimated in the available literature. This may be explained by the use of a restricted range of potential confounding variables as well as the dearth of studies using appropriate statistical techniques and study designs in order to minimize confounding. Each of these techniques and designs, including propensity score matching, has its strengths and limitations: A more comprehensive understanding of the causal role of parental expectations will stem from a convergence of findings from studies using different techniques and designs. PMID:25803867
Bansal, Ravi; Peterson, Bradley S
2018-06-01
Identifying regional effects of interest in MRI datasets usually entails testing a priori hypotheses across many thousands of brain voxels, requiring control for false positive findings in these multiple hypotheses testing. Recent studies have suggested that parametric statistical methods may have incorrectly modeled functional MRI data, thereby leading to higher false positive rates than their nominal rates. Nonparametric methods for statistical inference when conducting multiple statistical tests, in contrast, are thought to produce false positives at the nominal rate, which has thus led to the suggestion that previously reported studies should reanalyze their fMRI data using nonparametric tools. To understand better why parametric methods may yield excessive false positives, we assessed their performance when applied both to simulated datasets of 1D, 2D, and 3D Gaussian Random Fields (GRFs) and to 710 real-world, resting-state fMRI datasets. We showed that both the simulated 2D and 3D GRFs and the real-world data contain a small percentage (<6%) of very large clusters (on average 60 times larger than the average cluster size), which were not present in 1D GRFs. These unexpectedly large clusters were deemed statistically significant using parametric methods, leading to empirical familywise error rates (FWERs) as high as 65%: the high empirical FWERs were not a consequence of parametric methods failing to model spatial smoothness accurately, but rather of these very large clusters that are inherently present in smooth, high-dimensional random fields. In fact, when discounting these very large clusters, the empirical FWER for parametric methods was 3.24%. Furthermore, even an empirical FWER of 65% would yield on average less than one of those very large clusters in each brain-wide analysis. Nonparametric methods, in contrast, estimated distributions from those large clusters, and therefore, by construct rejected the large clusters as false positives at the nominal FWERs. Those rejected clusters were outlying values in the distribution of cluster size but cannot be distinguished from true positive findings without further analyses, including assessing whether fMRI signal in those regions correlates with other clinical, behavioral, or cognitive measures. Rejecting the large clusters, however, significantly reduced the statistical power of nonparametric methods in detecting true findings compared with parametric methods, which would have detected most true findings that are essential for making valid biological inferences in MRI data. Parametric analyses, in contrast, detected most true findings while generating relatively few false positives: on average, less than one of those very large clusters would be deemed a true finding in each brain-wide analysis. We therefore recommend the continued use of parametric methods that model nonstationary smoothness for cluster-level, familywise control of false positives, particularly when using a Cluster Defining Threshold of 2.5 or higher, and subsequently assessing rigorously the biological plausibility of the findings, even for large clusters. Finally, because nonparametric methods yielded a large reduction in statistical power to detect true positive findings, we conclude that the modest reduction in false positive findings that nonparametric analyses afford does not warrant a re-analysis of previously published fMRI studies using nonparametric techniques. Copyright © 2018 Elsevier Inc. All rights reserved.
Workplace exposure to secondhand smoke among non-smoking hospitality employees.
Lawhorn, Nikki A; Lirette, David K; Klink, Jenna L; Hu, Chih-Yang; Contreras, Cassandra; Ajori Bryant, Ty-Runet Pinkney; Brown, Lisanne F; Diaz, James H
2013-02-01
This article examines salivary cotinine concentrations to characterize secondhand smoke (SHS) exposure among non-smoking hospitality employees (bar and casino employees and musicians who perform in bars) who are exposed to SHS in the workplace. A pre-post test study design was implemented to assess SHS exposure in the workplace. The convenience sample of 41 non-smoking hospitality employees included 10 controls (non-smoking hospitality employees not exposed to SHS in the workplace). The findings demonstrate that post-shift saliva cotinine levels of hospitality employees who are exposed to SHS in the workplace are significantly higher than controls who work in smoke-free venues. Findings also suggested a statistically significant increase between pre- and post-shift saliva cotinine levels of hospitality employees who are exposed in the workplace. No statistically significant difference was noted across labor categories, suggesting that all exposed employees are at increased risk. The study results indicate that non-smoking hospitality employees exposed to SHS in the workplace have significantly higher cotinine concentration levels compared with their counterparts who work in smoke-free venues. Findings from other studies suggest that these increased cotinine levels are harmful to health. Given the potential impact on the health of exposed employees, this study further supports the efforts of tobacco prevention and control programs in advocating for comprehensive smoke-free air policies to protect bar and casino employees.
Clinical comparison of CR and screen film for imaging the critically ill neonate
NASA Astrophysics Data System (ADS)
Andriole, Katherine P.; Brasch, Robert C.; Gooding, Charles A.; Gould, Robert G.; Cohen, Pierre A.; Rencken, Ingo R.; Huang, H. K.
1996-05-01
A clinical comparison of computed radiography (CR) versus screen-film for imaging the critically-ill neonate is performed, utilizing a modified (hybrid) film cassette containing a CR (standard ST-V) imaging plate, a conventional screen and film, allowing simultaneous acquisition of perfectly matched CR and plain film images. For 100 portable neonatal chest and abdominal projection radiographs, plain film was subjectively compared to CR hardcopy. Three pediatric radiologists graded overall image quality on a scale of one (poor) to five (excellent), as well as visualization of various anatomic structures (i.e., lung parenchyma, pulmonary vasculature, tubes/lines) and pathological findings (i.e., pulmonary interstitial emphysema, pleural effusion, pneumothorax). Results analyzed using a combined kappa statistic of the differences between scores from each matched set, combined over the three readers showed no statistically significant difference in overall image quality between screen- film and CR (p equals 0.19). Similarly, no statistically significant difference was seen between screen-film and CR for anatomic structure visualization and for visualization of pathological findings. These results indicate that the image quality of CR is comparable to plain film, and that CR may be a suitable alternative to screen-film imaging for portable neonatal chest and abdominal examinations.
Statistical Analysis of the Indus Script Using n-Grams
Yadav, Nisha; Joglekar, Hrishikesh; Rao, Rajesh P. N.; Vahia, Mayank N.; Adhikari, Ronojoy; Mahadevan, Iravatham
2010-01-01
The Indus script is one of the major undeciphered scripts of the ancient world. The small size of the corpus, the absence of bilingual texts, and the lack of definite knowledge of the underlying language has frustrated efforts at decipherment since the discovery of the remains of the Indus civilization. Building on previous statistical approaches, we apply the tools of statistical language processing, specifically n-gram Markov chains, to analyze the syntax of the Indus script. We find that unigrams follow a Zipf-Mandelbrot distribution. Text beginner and ender distributions are unequal, providing internal evidence for syntax. We see clear evidence of strong bigram correlations and extract significant pairs and triplets using a log-likelihood measure of association. Highly frequent pairs and triplets are not always highly significant. The model performance is evaluated using information-theoretic measures and cross-validation. The model can restore doubtfully read texts with an accuracy of about 75%. We find that a quadrigram Markov chain saturates information theoretic measures against a held-out corpus. Our work forms the basis for the development of a stochastic grammar which may be used to explore the syntax of the Indus script in greater detail. PMID:20333254
Neuropsychological study of IQ scores in offspring of parents with bipolar I disorder.
Sharma, Aditya; Camilleri, Nigel; Grunze, Heinz; Barron, Evelyn; Le Couteur, James; Close, Andrew; Rushton, Steven; Kelly, Thomas; Ferrier, Ian Nicol; Le Couteur, Ann
2017-01-01
Studies comparing IQ in Offspring of Bipolar Parents (OBP) with Offspring of Healthy Controls (OHC) have reported conflicting findings. They have included OBP with mental health/neurodevelopmental disorders and/or pharmacological treatment which could affect results. This UK study aimed to assess IQ in OBP with no mental health/neurodevelopmental disorder and assess the relationship of sociodemographic variables with IQ. IQ data using the Wechsler Abbreviated Scale of Intelligence (WASI) from 24 OBP and 34 OHC from the North East of England was analysed using mixed-effects modelling. All participants had IQ in the average range. OBP differed statistically significantly from OHC on Full Scale IQ (p = .001), Performance IQ (PIQ) (p = .003) and Verbal IQ (VIQ) (p = .001) but not on the PIQ-VIQ split. OBP and OHC groups did not differ on socio-economic status (SES) and gender. SES made a statistically significant contribution to the variance of IQ scores (p = .001). Using a robust statistical model of analysis, the OBP with no current/past history of mental health/neurodevelopmental disorders had lower IQ scores compared to OHC. This finding should be borne in mind when assessing and recommending interventions for OBP.
Tarescavage, Anthony M; Alosco, Michael L; Ben-Porath, Yossef S; Wood, Arcangela; Luna-Jones, Lynn
2015-04-01
We investigated the internal structure comparability of Minnesota Multiphasic Personality Inventory-2-Restructured Form (MMPI-2-RF) scores derived from the MMPI-2 and MMPI-2-RF booklets in a sample of 320 criminal defendants (229 males and 54 females). After exclusion of invalid protocols, the final sample consisted of 96 defendants who were administered the MMPI-2-RF booklet and 83 who completed the MMPI-2. No statistically significant differences in MMPI-2-RF invalidity rates were observed between the two forms. Individuals in the final sample who completed the MMPI-2-RF did not statistically differ on demographics or referral question from those who were administered the MMPI-2 booklet. Independent t tests showed no statistically significant differences between MMPI-2-RF scores generated with the MMPI-2 and MMPI-2-RF booklets on the test's substantive scales. Statistically significant small differences were observed on the revised Variable Response Inconsistency (VRIN-r) and True Response Inconsistency (TRIN-r) scales. Cronbach's alpha and standard errors of measurement were approximately equal between the booklets for all MMPI-2-RF scales. Finally, MMPI-2-RF intercorrelations produced from the two forms yielded mostly small and a few medium differences, indicating that discriminant validity and test structure are maintained. Overall, our findings reflect the internal structure comparability of MMPI-2-RF scale scores generated from MMPI-2 and MMPI-2-RF booklets. Implications of these results and limitations of these findings are discussed. © The Author(s) 2014.
Novel Therapeutic Targets to Treat Social Behavior Deficits in Autism and Related Disorders
2015-10-01
studies and statistical consultation and other intellectual contributions as needed. W81XWH-12-1-0506 (Gould, PI) 09/30/12 – 09/29/2015 Gould et al., 13...report shall include negative as well as positive findings. Include problems in accomplishing any of the tasks. Statistical tests of significance...Release. DO NOT USE THE WORD " WHEN MARKING DOCUMENTS. DELINQUENT REPORTS If the recipient is delinquent on reporting requirements for other USAMRAA
Spatial scan statistics for detection of multiple clusters with arbitrary shapes.
Lin, Pei-Sheng; Kung, Yi-Hung; Clayton, Murray
2016-12-01
In applying scan statistics for public health research, it would be valuable to develop a detection method for multiple clusters that accommodates spatial correlation and covariate effects in an integrated model. In this article, we connect the concepts of the likelihood ratio (LR) scan statistic and the quasi-likelihood (QL) scan statistic to provide a series of detection procedures sufficiently flexible to apply to clusters of arbitrary shape. First, we use an independent scan model for detection of clusters and then a variogram tool to examine the existence of spatial correlation and regional variation based on residuals of the independent scan model. When the estimate of regional variation is significantly different from zero, a mixed QL estimating equation is developed to estimate coefficients of geographic clusters and covariates. We use the Benjamini-Hochberg procedure (1995) to find a threshold for p-values to address the multiple testing problem. A quasi-deviance criterion is used to regroup the estimated clusters to find geographic clusters with arbitrary shapes. We conduct simulations to compare the performance of the proposed method with other scan statistics. For illustration, the method is applied to enterovirus data from Taiwan. © 2016, The International Biometric Society.
Wishaupt, Jérôme O; Ploeg, Tjeerd van der; Smeets, Leo C; Groot, Ronald de; Versteegh, Florens G A; Hartwig, Nico G
2017-05-01
The relation between viral load and disease severity in childhood acute respiratory tract infections (ARI) is not fully understood. To assess the clinical relevance of the relation between viral load, determined by cycle threshold (CT) value of real-time reverse transcription-polymerase chain reaction assays and disease severity in children with single- and multiple viral ARI. 582 children with ARI were prospectively followed and tested for 15 viruses. Correlations were calculated between CT values and clinical parameters. In single viral ARI, statistically significant correlations were found between viral loads of Respiratory Syncytial Virus (RSV) and hospitalization and between viral loads of Human Coronavirus (HCoV) and a disease severity score. In multiple-viral ARI, statistically significant correlations between viral load and clinical parameters were found. In RSV-Rhinovirus (RV) multiple infections, a low viral load of RV was correlated with a high length of hospital stay and a high duration of extra oxygen use. The mean CT value for RV, HCoV and Parainfluenza virus was significantly lower in single- versus multiple infections. Although correlations between CT values and clinical parameters in patients with single and multiple viral infection were found, the clinical importance of these findings is limited because individual differences in host-, viral and laboratory factors complicate the interpretation of statistically significant findings. In multiple infections, viral load cannot be used to differentiate between disease causing virus and innocent bystanders. Copyright © 2017 Elsevier B.V. All rights reserved.
Governance and Regional Variation of Homicide Rates: Evidence From Cross-National Data.
Cao, Liqun; Zhang, Yan
2017-01-01
Criminological theories of cross-national studies of homicide have underestimated the effects of quality governance of liberal democracy and region. Data sets from several sources are combined and a comprehensive model of homicide is proposed. Results of the spatial regression model, which controls for the effect of spatial autocorrelation, show that quality governance, human development, economic inequality, and ethnic heterogeneity are statistically significant in predicting homicide. In addition, regions of Latin America and non-Muslim Sub-Saharan Africa have significantly higher rates of homicides ceteris paribus while the effects of East Asian countries and Islamic societies are not statistically significant. These findings are consistent with the expectation of the new modernization and regional theories. © The Author(s) 2015.
Fani, Parisa; Patlas, Michael N; Monteiro, Sandra; Katz, Douglas S
2018-02-02
To determine the yield of non-contrast multi-detector computed tomography (MDCT) of the abdomen and pelvis in diagnosing ureteral calculi as well as other alternative acute conditions in male vs in female adult patients presenting to the emergency department with new onset of symptoms. Our institutional review board approved a retrospective review of the official reports of the non-contrast MDCT examinations of the abdomen and pelvis performed on adults (18 years and older) presenting to our emergency department with a suspected ureteral calculus from October 1, 2011 to October 30, 2013. Patients with recently documented ureteral calculi, known urinary tract infection, malignancy, and trauma were excluded from the study. From a total of 1097 non-contrast MDCT examinations of the abdomen and pelvis over the 2-year period, 400 randomly selected examinations were reviewed (approximately one-third of all the examinations). We compared the prevalence of ureteral calculi between the male and female population. P values and confidence intervals were determined using software Stata 14. Other acute intra-abdominal and intra-pelvic findings amenable to prompt medical care were also documented and analyzed separately. The mean patient age was 55.2 years, with a range of 19-90 years. This included 170 female (mean age 56.8 years) and 230 male patients (mean age 54.2 years). Ureteral calculi were detected in 170 (42.5%) of the patients [111 males (48%) and 59 females (34.7%)] with a prevalence which was statistically significantly higher in the male patients compared to in the female patients (P < 0.01, confidence level of 95% and CI of 13.2-13.4). An alternative diagnosis was made based on the MDCT findings in 49 patient cases (12.25 %), including 26 females (15.29%) and 23 males (10.00%). There was no statistically significant difference in alternative acute findings in male compared to in female patients (P > 0.05). This was with the exception of acute pyelonephritis, which was statistically significantly higher in the female patients (P < 0.01). The likelihood of making the diagnosis of a ureteral calculus on non-contrast MDCT of the abdomen and pelvis was statistically significantly higher in male patients compared with female patients presenting to our emergency department. However, there was no statistically significant difference in the alternative diagnoses, with the exception of pyelonephritis, which was more common in women. Copyright © 2018 Elsevier Inc. All rights reserved.
Saadati, Farzaneh; Ahmad Tarmizi, Rohani; Mohd Ayub, Ahmad Fauzi; Abu Bakar, Kamariah
2015-01-01
Because students' ability to use statistics, which is mathematical in nature, is one of the concerns of educators, embedding within an e-learning system the pedagogical characteristics of learning is 'value added' because it facilitates the conventional method of learning mathematics. Many researchers emphasize the effectiveness of cognitive apprenticeship in learning and problem solving in the workplace. In a cognitive apprenticeship learning model, skills are learned within a community of practitioners through observation of modelling and then practice plus coaching. This study utilized an internet-based Cognitive Apprenticeship Model (i-CAM) in three phases and evaluated its effectiveness for improving statistics problem-solving performance among postgraduate students. The results showed that, when compared to the conventional mathematics learning model, the i-CAM could significantly promote students' problem-solving performance at the end of each phase. In addition, the combination of the differences in students' test scores were considered to be statistically significant after controlling for the pre-test scores. The findings conveyed in this paper confirmed the considerable value of i-CAM in the improvement of statistics learning for non-specialized postgraduate students.
Vukadinovic, V; Chiou, J D; Morris, D L
2015-05-01
Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) can be complicated by pulmonary emboli (PE). Patients are at high risk due to surgery, underlying malignancy, immobility and indwelling lines. This paper aims to identify clinically significant signs and symptoms preceding acute PE in post CRS-HIPEC patients, assess the PE investigative approach in this population and the significance of PE on patient management. 25 cases with a positive and 50 controls with a negative CTPA for PE were isolated from the peritonectomy database at St George Hospital Sydney, January 2006 to July 2013. Vital signs, patient symptoms, adjunct investigation findings and patient outcomes were collected and graphed in Microsoft Excel. P values and 95% confidence intervals were calculated using GraphPad Prism version 6. 25 of 562 (4.4%) CRS-HIPEC patients were diagnosed with acute PE. Raised body temperature was the only statistically significant clinical finding that differentiated cases from controls (p value 0.02). Arterial blood gas results did not correlate with PE (p values 0.62; 0.29; 0.55, 0.84). Troponin, ECG and CXR were not routinely conducted. CXR and CTPA findings were similar between cases and controls (Table 4). PE patients required lower supplementary oxygen and escalation of care. Body temperature is the only statistically significant clinical finding observed with PE. We recommend a standardised investigative approach consisting of troponin, ECG and CXR. PE in CRS-HIPEC does not cause significant cardio-respiratory dysfunction, or escalation of care. PE rates are higher than other major surgeries, thus we propose a trial with increased chemical prophylaxis in CRS-HIPEC patients. Copyright © 2015 Elsevier Ltd. All rights reserved.
Are studies reporting significant results more likely to be published?
Koletsi, Despina; Karagianni, Anthi; Pandis, Nikolaos; Makou, Margarita; Polychronopoulou, Argy; Eliades, Theodore
2009-11-01
Our objective was to assess the hypothesis that there are variations of the proportion of articles reporting a significant effect, with a higher percentage of those articles published in journals with impact factors. The contents of 5 orthodontic journals (American Journal of Orthodontics and Dentofacial Orthopedics, Angle Orthodontist, European Journal of Orthodontics, Journal of Orthodontics, and Orthodontics and Craniofacial Research), published between 2004 and 2008, were hand-searched. Articles with statistical analysis of data were included in the study and classified into 4 categories: behavior and psychology, biomaterials and biomechanics, diagnostic procedures and treatment, and craniofacial growth, morphology, and genetics. In total, 2622 articles were examined, with 1785 included in the analysis. Univariate and multivariate logistic regression analyses were applied with statistical significance as the dependent variable, and whether the journal had an impact factor, the subject, and the year were the independent predictors. A higher percentage of articles showed significant results relative to those without significant associations (on average, 88% vs 12%) for those journals. Overall, these journals published significantly more studies with significant results, ranging from 75% to 90% (P = 0.02). Multivariate modeling showed that journals with impact factors had a 100% increased probability of publishing a statistically significant result compared with journals with no impact factor (odds ratio [OR], 1.99; 95% CI, 1.19-3.31). Compared with articles on biomaterials and biomechanics, all other subject categories showed lower probabilities of significant results. Nonsignificant findings in behavior and psychology and diagnosis and treatment were 1.8 (OR, 1.75; 95% CI, 1.51-2.67) and 3.5 (OR, 3.50; 95% CI, 2.27-5.37) times more likely to be published, respectively. Journals seem to prefer reporting significant results; this might be because of authors' perceptions of the importance of their findings and editors' and reviewers' preferences for significant results. The implication of this factor in the reliability of systematic reviews is discussed.
Identifying patients with hypertension: a case for auditing electronic health record data.
Baus, Adam; Hendryx, Michael; Pollard, Cecil
2012-01-01
Problems in the structure, consistency, and completeness of electronic health record data are barriers to outcomes research, quality improvement, and practice redesign. This nonexperimental retrospective study examines the utility of importing de-identified electronic health record data into an external system to identify patients with and at risk for essential hypertension. We find a statistically significant increase in cases based on combined use of diagnostic and free-text coding (mean = 1,256.1, 95% CI 1,232.3-1,279.7) compared to diagnostic coding alone (mean = 1,174.5, 95% CI 1,150.5-1,198.3). While it is not surprising that significantly more patients are identified when broadening search criteria, the implications are critical for quality of care, the movement toward the National Committee for Quality Assurance's Patient-Centered Medical Home program, and meaningful use of electronic health records. Further, we find a statistically significant increase in potential cases based on the last two or more blood pressure readings greater than or equal to 140/90 mm Hg (mean = 1,353.9, 95% CI 1,329.9-1,377.9).
Mental health benefits of interactions with nature in children and teenagers: a systematic review.
Tillmann, Suzanne; Tobin, Danielle; Avison, William; Gilliland, Jason
2018-06-27
It is commonly believed that nature has positive impacts on children's health, including physical, mental and social dimensions. This review focuses on how accessibility to, exposure to and engagement with nature affects the mental health of children and teenagers. Ten academic databases were used to systematically search and identify primary research papers in English or French from 1990 to 1 March 2017. Papers were included for review based on their incorporation of nature, children and teenagers (0-18 years), quantitative results and focus on mental health. Of the 35 papers included in the review, the majority focused on emotional well-being and attention deficit disorder/hyperactivity disorder. Other outcome measures included overall mental health, self-esteem, stress, resilience, depression and health-related quality of life. About half of all reported findings revealed statistically significant positive relationships between nature and mental health outcomes and almost half reported no statistical significance. Findings support the contention that nature positively influences mental health; however, in most cases, additional research with more rigorous study designs and objective measures of both nature and mental health outcomes are needed to confirm statistically significant relationships. Existing evidence is limited by the cross-sectional nature of most papers. © 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.
[Clinical profile of cytomegalovirus (CMV) enterocolitis in acquired immunodeficiency syndrome].
De Lima, D B; Fernandes, O; Gomes, V R; Da Silva, E J; De Pinho, P R; De Paiva, D D
2000-01-01
To determine the clinical profile of CMV colitis in AIDS patients, comparing clinical, endoscopic parameters and survival time between 2 groups of AIDS patients having chronic diarrhea. Group A being CMV colitis and group B without CMV colitis. 48 patients with diarrhea that lasted more than 30 days, being 27 in Group A and 21 in Group B, were studied. Age, risk factors, interval time between the diagnosis of HIV infection and the beginning of diarrhea, hematochesia, the endoscopic findings and life table in both groups, were analysed. All of them were diagnosed by stool culture and stools for ovum and parasites, along colonoscopy with biopsies. The unpaired t test was used to assess statistical significance of differences observed in the means of continuous and the chi-square with Yates correction for non-parametric variables. The survival curves were assessed by the Kaplan-Meier and the Mantel-Haenszel's tests. A P value of less than 0,05 was considered to indicate statistical significance. The mucosal lesions associated with the CMV infection are typically ulcerative on a background of hemorrhagic erythema 14 (51,8%) p < 0,01. The life table analysis disclosed shorter survival time in the CMV colitis group 0,005> P>0,001. The others studied data did not achieve statistical significance. AIDS patients with CMV colitis have a poorer long-term survival. Among the colonoscopic findings, ulcerations with hemorrhagic background were the most common lesions.
NASA Astrophysics Data System (ADS)
Yan, Jiawei; Wang, Shizhuo; Xia, Ke; Ke, Youqi
2018-01-01
We present first-principles analysis of interfacial disorder effects on spin-dependent tunneling statistics in thin Fe/MgO/Fe magnetic tunnel junctions. We find that interfacial disorder scattering can significantly modulate the tunneling statistics in the minority spin of the parallel configuration (PC) while all other spin channels remain dominated by the Poissonian process. For the minority-spin channel of PC, interfacial disorder scattering favors the formation of resonant tunneling channels by lifting the limitation of symmetry conservation at low concentration, presenting an important sub-Poissonian process in PC, but is destructive to the open channels at high concentration. We find that the important modulation of tunneling statistics is independent of the type of interfacial disorder. A bimodal distribution function of transmission with disorder dependence is introduced and fits very well our first-principles results. The increase of MgO thickness can quickly change the tunneling from a sub-Poissonian to Poissonian dominated process in the minority spin of PC with disorder. Our results provide a sensitive detection method of an ultralow concentration of interfacial defects.
ERIC Educational Resources Information Center
Trafimow, David
2017-01-01
There has been much controversy over the null hypothesis significance testing procedure, with much of the criticism centered on the problem of inverse inference. Specifically, p gives the probability of the finding (or one more extreme) given the null hypothesis, whereas the null hypothesis significance testing procedure involves drawing a…
ERIC Educational Resources Information Center
Cicchetti, Domenic V.; Koenig, Kathy; Klin, Ami; Volkmar, Fred R.; Paul, Rhea; Sparrow, Sara
2011-01-01
The objectives of this report are: (a) to trace the theoretical roots of the concept clinical significance that derives from Bayesian thinking, Marginal Utility/Diminishing Returns in Economics, and the "just noticeable difference", in Psychophysics. These concepts then translated into: Effect Size (ES), strength of agreement, clinical…
Neves, F S; Souza, T C; Almeida, S M; Haiter-Neto, F; Freitas, D Q; Bóscolo, F N
2012-01-01
Objectives The aim of this study was to assess the reliability of four panoramic radiographic findings, both individually and in association, in predicting the absence of corticalization between the mandibular canal and the third molar on cone beam CT (CBCT) images. Methods The sample consisted of 72 individuals (142 mandibular third molars) who underwent pre-operative radiographic evaluation before extraction of impacted mandibular third molars. On panoramic radiographs, the most common signs of corticalization (darkening of roots, diversion of mandibular canal, narrowing of mandibular canal and interruption of white line) and the presence or absence of corticalization between the mandibular third molar and the mandibular canal on CBCT images were evaluated. Results Darkening of roots and interruption of white line associated with the absence of corticalization between the mandibular third molar and the mandibular canal on CBCT images were statistically significant, both as isolated findings (p = 0.0001 and p = 0.0006, respectively) and in association (p = 0.002). No statistically significant association was observed for the other panoramic radiographic findings, either individually or in association (p > 0.05). Conclusion Darkening of roots and interruption of white line observed on panoramic radiographs, both as isolated findings and in association, were effective in determining the risk relationship between the tooth roots and the mandibular canal, requiring three-dimensional evaluation of the case. PMID:22282507
Environmental Health Practice: Statistically Based Performance Measurement
Enander, Richard T.; Gagnon, Ronald N.; Hanumara, R. Choudary; Park, Eugene; Armstrong, Thomas; Gute, David M.
2007-01-01
Objectives. State environmental and health protection agencies have traditionally relied on a facility-by-facility inspection-enforcement paradigm to achieve compliance with government regulations. We evaluated the effectiveness of a new approach that uses a self-certification random sampling design. Methods. Comprehensive environmental and occupational health data from a 3-year statewide industry self-certification initiative were collected from representative automotive refinishing facilities located in Rhode Island. Statistical comparisons between baseline and postintervention data facilitated a quantitative evaluation of statewide performance. Results. The analysis of field data collected from 82 randomly selected automotive refinishing facilities showed statistically significant improvements (P<.05, Fisher exact test) in 4 major performance categories: occupational health and safety, air pollution control, hazardous waste management, and wastewater discharge. Statistical significance was also shown when a modified Bonferroni adjustment for multiple comparisons was performed. Conclusions. Our findings suggest that the new self-certification approach to environmental and worker protection is effective and can be used as an adjunct to further enhance state and federal enforcement programs. PMID:17267709
Performance of cancer cluster Q-statistics for case-control residential histories
Sloan, Chantel D.; Jacquez, Geoffrey M.; Gallagher, Carolyn M.; Ward, Mary H.; Raaschou-Nielsen, Ole; Nordsborg, Rikke Baastrup; Meliker, Jaymie R.
2012-01-01
Few investigations of health event clustering have evaluated residential mobility, though causative exposures for chronic diseases such as cancer often occur long before diagnosis. Recently developed Q-statistics incorporate human mobility into disease cluster investigations by quantifying space- and time-dependent nearest neighbor relationships. Using residential histories from two cancer case-control studies, we created simulated clusters to examine Q-statistic performance. Results suggest the intersection of cases with significant clustering over their life course, Qi, with cases who are constituents of significant local clusters at given times, Qit, yielded the best performance, which improved with increasing cluster size. Upon comparison, a larger proportion of true positives were detected with Kulldorf’s spatial scan method if the time of clustering was provided. We recommend using Q-statistics to identify when and where clustering may have occurred, followed by the scan method to localize the candidate clusters. Future work should investigate the generalizability of these findings. PMID:23149326
Pattern statistics on Markov chains and sensitivity to parameter estimation
Nuel, Grégory
2006-01-01
Background: In order to compute pattern statistics in computational biology a Markov model is commonly used to take into account the sequence composition. Usually its parameter must be estimated. The aim of this paper is to determine how sensitive these statistics are to parameter estimation, and what are the consequences of this variability on pattern studies (finding the most over-represented words in a genome, the most significant common words to a set of sequences,...). Results: In the particular case where pattern statistics (overlap counting only) computed through binomial approximations we use the delta-method to give an explicit expression of σ, the standard deviation of a pattern statistic. This result is validated using simulations and a simple pattern study is also considered. Conclusion: We establish that the use of high order Markov model could easily lead to major mistakes due to the high sensitivity of pattern statistics to parameter estimation. PMID:17044916
Pattern statistics on Markov chains and sensitivity to parameter estimation.
Nuel, Grégory
2006-10-17
In order to compute pattern statistics in computational biology a Markov model is commonly used to take into account the sequence composition. Usually its parameter must be estimated. The aim of this paper is to determine how sensitive these statistics are to parameter estimation, and what are the consequences of this variability on pattern studies (finding the most over-represented words in a genome, the most significant common words to a set of sequences,...). In the particular case where pattern statistics (overlap counting only) computed through binomial approximations we use the delta-method to give an explicit expression of sigma, the standard deviation of a pattern statistic. This result is validated using simulations and a simple pattern study is also considered. We establish that the use of high order Markov model could easily lead to major mistakes due to the high sensitivity of pattern statistics to parameter estimation.
Koami, Hiroyuki; Sakamoto, Yuichiro; Sakurai, Ryota; Ohta, Miho; Imahase, Hisashi; Yahata, Mayuko; Umeka, Mitsuru; Miike, Toru; Nagashima, Futoshi; Iwamura, Takashi; Yamada, Kosuke Chris; Inoue, Satoshi
2016-08-01
The aim of this study is to evaluate the hematological differences between septic and traumatic disseminated intravascular coagulation (DIC) using the rotational thromboelastometry (ROTEM).This retrospective study includes all sepsis or severe trauma patients transported to our emergency department who underwent ROTEM from 2013 to 2014. All patients were divided into 2 groups based on the presence of DIC diagnosed by the Japanese Association for Acute Medicine (JAAM) DIC score. We statistically analyzed the demographics, clinical characteristics, laboratory data, ROTEM findings (EXTEM and FIBTEM), and outcome.Fifty-seven patients (30 sepsis and 27 severe trauma) were included in primary analysis. Sepsis cases were significantly older and had higher systemic inflammatory response syndrome (SIRS) scores, whereas there were no significant differences in other parameters including Acute Physiology and Chronic Health Evaluation (APACHE) II score, sequential organ failure assessment (SOFA) score. Twenty-six patients (14 sepsis and 12 severe trauma) were diagnosed with DIC. The Septic DIC (S-DIC) group was significantly older and had higher DIC scores than the traumatic DIC (T-DIC) group. Hematologic examination revealed significantly higher CRP, fibrinogen, lower FDP, DD, and higher FDP/DD ratio were found in the S-DIC group in comparison with the T-DIC group. ROTEM findings showed that the A10, A20, and MCF in the FIBTEM test were significantly higher in the S-DIC group. However, no statistical differences were confirmed in the LI30, LI45, and ML in EXTEM test.The plasma fibrinogen level and fibrinogen based clot firmness in whole-blood test revealed statistical significance between septic and traumatic DIC patients.
2000-06-01
data have focused on drug use and related factors, the study content is much broader (as the title implies) and includes vocational and educational ...over time. The present reporting, in contrast, focuses primarily on trend data and certain subgroup differences, using simple statistics (percentages...report are included on all forms of the 8th and 10th grade surveys. Tests for the statistical significance of mean differences between data collected in
Hormone replacement therapy diminishes hearing in peri-menopausal mice.
Price, Katharine; Zhu, Xiaoxia; Guimaraes, Patricia F; Vasilyeva, Olga N; Frisina, Robert D
2009-06-01
We recently discovered that progestin in hormone replacement therapy (HRT) for post-menopausal women has detrimental effects on the ear and central auditory system [Guimaraes, P., Frisina, S.T., Mapes, F., Tadros, S.F., Frisina, D.R., Frisina, R.D., 2006. Progestin negatively affects hearing in aged women. Proc. Natl. Acad. Sci. - PNAS 103, 14246-14249]. To start determining the generality and neural bases of these human findings, the present study examined the effects of combination HRT (estrogen+progestin) and estrogen alone on hearing in peri-menopausal mice. Specifically, auditory brainstem responses (ABRs-sensitivity of the auditory system) and distortion-product otoacoustic emissions (DPOAEs-cochlear outer hair cell system) were employed. Middle age female CBA mice received either a time-release, subcutaneous implanted pellet of estrogen+progestin, estrogen alone, or placebo. Longitudinal comparisons of ABR threshold data obtained at 4 months of treatment revealed statistically significant declines in auditory sensitivity over time for the combined estrogen+progestin treatment group, with the estrogen only group revealing milder changes at 3, 6 and 32 kHz. DPOAE testing revealed statistically significant differences for the estrogen+progestin treatment group in the high and middle frequency ranges (15-29 and 30-45 kHz) after as early as 2 months of treatment (p<0.01 and p<0.001, respectively). Statistically significant changes were also seen at 4 months of treatment across all frequencies for the combined HRT group. These data suggest that estrogen+progestin HRT therapy of 4 months duration impairs outer hair cell functioning and overall auditory sensitivity. These findings indicate that estrogen+progestin HRT may actually accelerate age-related hearing loss, relative to estrogen monotherapy; findings that are consistent with the clinical hearing loss observed in aging women that have taken combination HRT.
A Quantitative Study of Empathy in Pakistani Medical Students: A Multicentered Approach.
Tariq, Nabia; Rasheed, Tariq; Tavakol, Mohsen
2017-10-01
To examine the empathy level of undergraduate medical students in Pakistan. Three hypotheses are developed based on the literature review. (1) Female medical students have a higher level of empathy than do male students. (2) Empathy scores vary during the medical school years in Pakistani students. (3) Medical students interested in people-oriented specialties would score higher than the students interested in technology-oriented specialties. This is a quantitative inquiry approach using a cross-sectional design of 1453 students from 8 Pakistani medical schools, both private and state. The sample consists of 41.1% (n = 597) male students and 58.9% (n = 856) female students. Empirical data are collected using the Jefferson Scale of Physician Empathy (JSPE), a well-validated self-administered questionnaire. The mean empathy score among students is 4.77 with a standard deviation of 0.72. The results show that there is no statistically significant association between the empathy scores and gender, t(1342.36) = -0.053, P = .95). There is a statistically significant difference between the empathy scores and the years of medical school, F(14, 1448) = 4.95, P = .01. Concerning the specialty interests, there is no statistically significant difference between the empathy score and specialty interests. The findings of this study showed that in Western countries, medical students performed better than Pakistani medical students on the empathy scale. This finding has important implications for Pakistani medical educators to improve the interpersonal skills of medical students in the context of patient care. Inconsistent with our expectations and experiences, our findings do not support that female medical students scored better than their male counterparts on the empathy scale. Because of the nature of a cross-sectional study, it is impossible to argue the decline of empathy during medical school training.
NASA Astrophysics Data System (ADS)
Stige, Leif Chr.; Langangen, Øystein; Yaragina, Natalia A.; Vikebø, Frode B.; Bogstad, Bjarte; Ottersen, Geir; Stenseth, Nils Chr.; Hjermann, Dag Ø.
2015-05-01
Understanding the causes of the large interannual fluctuations in the recruitment to many marine fishes is a key challenge in fisheries ecology. We here propose that the combination of mechanistic and statistical modelling of the pelagic early life stages (ELS) prior to recruitment can be a powerful approach for improving our understanding of local-scale and population-scale dynamics. Specifically, this approach allows separating effects of ocean transport and survival, and thereby enhances the knowledge of the processes that regulate recruitment. We analyse data on the pelagic eggs, larvae and post-larvae of Northeast Arctic cod and on copepod nauplii, the main prey of the cod larvae. The data originate from two surveys, one in spring and one in summer, for 30 years. A coupled physical-biological model is used to simulate the transport, ambient temperature and development of cod ELS from spawning through spring and summer. The predictions from this model are used as input in a statistical analysis of the summer data, to investigate effects of covariates thought to be linked to growth and survival. We find significant associations between the local-scale ambient copepod nauplii concentration and temperature in spring and the local-scale occurrence of cod (post)larvae in summer, consistent with effects on survival. Moreover, years with low copepod nauplii concentrations and low temperature in spring are significantly associated with lower mean length of the cod (post)larvae in summer, likely caused in part by higher mortality leading to increased dominance of young and hence small individuals. Finally, we find that the recruitment at age 3 is strongly associated with the mean body length of the cod ELS, highlighting the biological significance of the findings.
Shuman, William P; Chan, Keith T; Busey, Janet M; Mitsumori, Lee M; Choi, Eunice; Koprowicz, Kent M; Kanal, Kalpana M
2014-12-01
To investigate whether reduced radiation dose liver computed tomography (CT) images reconstructed with model-based iterative reconstruction ( MBIR model-based iterative reconstruction ) might compromise depiction of clinically relevant findings or might have decreased image quality when compared with clinical standard radiation dose CT images reconstructed with adaptive statistical iterative reconstruction ( ASIR adaptive statistical iterative reconstruction ). With institutional review board approval, informed consent, and HIPAA compliance, 50 patients (39 men, 11 women) were prospectively included who underwent liver CT. After a portal venous pass with ASIR adaptive statistical iterative reconstruction images, a 60% reduced radiation dose pass was added with MBIR model-based iterative reconstruction images. One reviewer scored ASIR adaptive statistical iterative reconstruction image quality and marked findings. Two additional independent reviewers noted whether marked findings were present on MBIR model-based iterative reconstruction images and assigned scores for relative conspicuity, spatial resolution, image noise, and image quality. Liver and aorta Hounsfield units and image noise were measured. Volume CT dose index and size-specific dose estimate ( SSDE size-specific dose estimate ) were recorded. Qualitative reviewer scores were summarized. Formal statistical inference for signal-to-noise ratio ( SNR signal-to-noise ratio ), contrast-to-noise ratio ( CNR contrast-to-noise ratio ), volume CT dose index, and SSDE size-specific dose estimate was made (paired t tests), with Bonferroni adjustment. Two independent reviewers identified all 136 ASIR adaptive statistical iterative reconstruction image findings (n = 272) on MBIR model-based iterative reconstruction images, scoring them as equal or better for conspicuity, spatial resolution, and image noise in 94.1% (256 of 272), 96.7% (263 of 272), and 99.3% (270 of 272), respectively. In 50 image sets, two reviewers (n = 100) scored overall image quality as sufficient or good with MBIR model-based iterative reconstruction in 99% (99 of 100). Liver SNR signal-to-noise ratio was significantly greater for MBIR model-based iterative reconstruction (10.8 ± 2.5 [standard deviation] vs 7.7 ± 1.4, P < .001); there was no difference for CNR contrast-to-noise ratio (2.5 ± 1.4 vs 2.4 ± 1.4, P = .45). For ASIR adaptive statistical iterative reconstruction and MBIR model-based iterative reconstruction , respectively, volume CT dose index was 15.2 mGy ± 7.6 versus 6.2 mGy ± 3.6; SSDE size-specific dose estimate was 16.4 mGy ± 6.6 versus 6.7 mGy ± 3.1 (P < .001). Liver CT images reconstructed with MBIR model-based iterative reconstruction may allow up to 59% radiation dose reduction compared with the dose with ASIR adaptive statistical iterative reconstruction , without compromising depiction of findings or image quality. © RSNA, 2014.
Primary laws and fine levels are associated with increases in seat belt use, 1997-2008
DOT National Transportation Integrated Search
2010-11-01
Increasing fine levels is a strategy that has potential to further raise seat belt use, in addition to primary law upgrades and high-visibility enforcement. Although the regression analyses did not find a statistically significant effect associated w...
Myths and Misconceptions about Using Qualitative Methods in Assessment
ERIC Educational Resources Information Center
Harper, Shaun R.; Kuh, George D.
2007-01-01
The value of qualitative assessment approaches has been underestimated primarily because they are often juxtaposed against long-standing quantitative traditions and the widely accepted premise that the best research produces generalizable and statistically significant findings. Institutional researchers avoid qualitative methods for at least three…
The Effect of Compliance-Gaining Strategy Choice and Communicator Style on Sales Success.
ERIC Educational Resources Information Center
Parrish-Sprowl, John; And Others
1994-01-01
Explores the relationship among compliance-gaining strategy choice, communicator image, and sales person effectiveness. Finds no statistically significant relationship between the use of compliance-gaining strategies and sales success, but indicates a link between communicator image and sales success. (SR)
Interventions to Improve the Quality of Outpatient Specialty Referral Requests: A Systematic Review.
Hendrickson, Chase D; Lacourciere, Stacy L; Zanetti, Cole A; Donaldson, Patrick C; Larson, Robin J
2016-09-01
Requests for outpatient specialty consultations occur frequently but often are of poor quality because of incompleteness. The authors searched bibliographic databases, trial registries, and references during October 2014 for studies evaluating interventions to improve the quality of outpatient specialty referral requests compared to usual practice. Two reviewers independently extracted data and assessed quality. Findings were qualitatively summarized for completeness of information relayed in a referral request within naturally emerging intervention categories. Of 3495 articles screened, 11 were eligible. All 3 studies evaluating software-based interventions found statistically significant improvements. Among 4 studies evaluating template/pro forma interventions, completeness was uniformly improved but with variable or unreported statistical significance. Of 4 studies evaluating educational interventions, 2 favored the intervention and 2 found no difference. One study evaluating referral management was negative. Current evidence for improving referral request quality is strongest for software-based interventions and templates, although methodological quality varied and findings may be setting specific. © The Author(s) 2015.
Neighborhood archetypes for population health research: is there no place like home?
Weden, Margaret M; Bird, Chloe E; Escarce, José J; Lurie, Nicole
2011-01-01
This study presents a new, latent archetype approach for studying place in population health. Latent class analysis is used to show how the number, defining attributes, and change/stability of neighborhood archetypes can be characterized and tested for statistical significance. The approach is demonstrated using data on contextual determinants of health for US neighborhoods defined by census tracts in 1990 and 2000. Six archetypes (prevalence 13-20%) characterize the statistically significant combinations of contextual determinants of health from the social environment, built environment, commuting and migration patterns, and demographics and household composition of US neighborhoods. Longitudinal analyses based on the findings demonstrate notable stability (76.4% of neighborhoods categorized as the same archetype ten years later), with exceptions reflecting trends in (ex)urbanization, gentrification/downgrading, and racial/ethnic reconfiguration. The findings and approach is applicable to both research and practice (e.g. surveillance) and can be scaled up or down to study health and place in other geographical contexts or historical periods. Copyright © 2010 Elsevier Ltd. All rights reserved.
Effects of polymers on the spatial structure of turbulent flows
NASA Astrophysics Data System (ADS)
Sinhuber, Michael; Ballouz, Joseph G.; Ouellette, Nicholas T.
2017-11-01
It is well known that the addition of minor amounts of polymers to a turbulent water flow can significantly change its properties. One of the most prominent effects is the observed drastic reduction of drag in wall-bounded flows that is utilized in many engineering applications. Much of the research on polymers in turbulence has focused on their influence on the turbulent energy cascade and their interaction with the energy transfer processes. Much less investigated are their effects on the spatial structure of turbulent flows. In a classical von-Kárman swirling flow setup, we used Lagrangian particle tracking to obtain three-dimensional particle trajectories, velocities, and accelerations and find that polymers have a significant effect on Lagrangian measures of the turbulence structure such as radial distribution functions and the curvature of particle trajectories. We find that not only do the statistical distributions change, but also that polymers appear to affect the spatial statistics well beyond the size of the polymers themselves.
Karthik, R.; Mohan, N.
2017-01-01
Background: The practice of betel nut chewing with or without tobacco is still practiced in south india, salem inspite of its harmful effects. Methodology: 200 Patients visiting the outpatient department, Oral medicine and radiology from Aug 2015 to Aug 2016. Result and Conclusion: In our study, 3 women were exclusively churut smokers. Thirty-eight percent of the dental patients were beedi smoker, 32% were tobacco chewers, 12% were both betel nut and tobacco chewers, 8% were exclusively betel nut chewers, 1% of the dental population were exclusively churut smokers. Mean age group of the study population is 50.2 (14.4). There are 28 females and 172 males in the study group. Chi-square test revealed a statistically significant difference (P = 0.001) between males and females based on soft-tissue findings and no statistically significant difference (P = 0.572) between males and females based on distribution of hard-tissue findings. PMID:29284937
Factors that influence the use and perceptions of employee assistance programs at six worksites.
French, M T; Dunlap, L J; Roman, P M; Steele, P D
1997-10-01
Employee assistance programs (EAPs) have gained significant importance in contemporary worksites. This article uses data from 6 case studies to examine several research questions regarding the relationship between worker demographic (e.g., gender, job tenure, and marital status), substance use, and workplace policies and the actual and potential use of the company EAP. Unlike in most of the existing literature, the authors did not find that gender, marital status, or job dissatisfaction are statistically related to actual or potential EAP use at most worksites. However, job tenure and some substance use behaviors were related to actual EAP use in a positive and statistically significant way. Another important finding, underlying the credible integration of EAPs into worksite culture, is the positive and robust relationship between employee trust and confidence in the EAP and actual use. The results of our study both reinforce some long-established principles in the EAP field and encourage further consideration of other beliefs.
The effects of budget, delegation, and other variables on the future of school nursing.
Tetuan, Theresa M; Akagi, Cynthia G
2004-12-01
The purpose of this exploratory research study was to survey Kansas school nurses to determine the impact of budget, delegation, and other variables on the future of school nursing. Issues of education and certification status, educational budget, delegation, school nurse-to-student ratio, number of school buildings assigned, Metropolitan Statistical Area, and years of school nursing experience were also investigated. The Budget Impact School Nurse Questionnaire online survey was used to gather data. Findings revealed that school nurses were well prepared academically, but that many school nurses lacked certification. The use of UAPs and the future of school nursing were significantly affected by budget constraints, delegation, number of buildings assigned, legislative contact, and Metropolitan Statistical Area (urban location). Education in delegation and years of experience as a school nurse significantly affected opportunities for health education. The findings depicted budget, school nurse staffing, delegation, and geographic areas as the main variables that have an impact on school nursing.
Applications of statistical physics and information theory to the analysis of DNA sequences
NASA Astrophysics Data System (ADS)
Grosse, Ivo
2000-10-01
DNA carries the genetic information of most living organisms, and the of genome projects is to uncover that genetic information. One basic task in the analysis of DNA sequences is the recognition of protein coding genes. Powerful computer programs for gene recognition have been developed, but most of them are based on statistical patterns that vary from species to species. In this thesis I address the question if there exist universal statistical patterns that are different in coding and noncoding DNA of all living species, regardless of their phylogenetic origin. In search for such species-independent patterns I study the mutual information function of genomic DNA sequences, and find that it shows persistent period-three oscillations. To understand the biological origin of the observed period-three oscillations, I compare the mutual information function of genomic DNA sequences to the mutual information function of stochastic model sequences. I find that the pseudo-exon model is able to reproduce the mutual information function of genomic DNA sequences. Moreover, I find that a generalization of the pseudo-exon model can connect the existence and the functional form of long-range correlations to the presence and the length distributions of coding and noncoding regions. Based on these theoretical studies I am able to find an information-theoretical quantity, the average mutual information (AMI), whose probability distributions are significantly different in coding and noncoding DNA, while they are almost identical in all studied species. These findings show that there exist universal statistical patterns that are different in coding and noncoding DNA of all studied species, and they suggest that the AMI may be used to identify genes in different living species, irrespective of their taxonomic origin.
The psychophysiology of real-time financial risk processing.
Lo, Andrew W; Repin, Dmitry V
2002-04-01
A longstanding controversy in economics and finance is whether financial markets are governed by rational forces or by emotional responses. We study the importance of emotion in the decision-making process of professional securities traders by measuring their physiological characteristics (e.g., skin conductance, blood volume pulse, etc.) during live trading sessions while simultaneously capturing real-time prices from which market events can be detected. In a sample of 10 traders, we find statistically significant differences in mean electrodermal responses during transient market events relative to no-event control periods, and statistically significant mean changes in cardiovascular variables during periods of heightened market volatility relative to normal-volatility control periods. We also observe significant differences in these physiological responses across the 10 traders that may be systematically related to the traders' levels of experience.
A Survey of ChalleNGe Program Teachers: Their Characteristics and Pedagogical Approaches
2015-08-01
aloud, and reading books of their choice during class. As we have done with other pedagogical methods, we estimated the relationship between the...significant relationships between pedagogical practices and average cadet outcomes. When considering the impact of specific math subjects and the extent...ChalleNGe). Although we did find some statistically significant relationships between pedagogical approaches and cadets’ average outcomes, we
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.
Spatiotemporal Analysis of the Ebola Hemorrhagic Fever in West Africa in 2014
NASA Astrophysics Data System (ADS)
Xu, M.; Cao, C. X.; Guo, H. F.
2017-09-01
Ebola hemorrhagic fever (EHF) is an acute hemorrhagic diseases caused by the Ebola virus, which is highly contagious. This paper aimed to explore the possible gathering area of EHF cases in West Africa in 2014, and identify endemic areas and their tendency by means of time-space analysis. We mapped distribution of EHF incidences and explored statistically significant space, time and space-time disease clusters. We utilized hotspot analysis to find the spatial clustering pattern on the basis of the actual outbreak cases. spatial-temporal cluster analysis is used to analyze the spatial or temporal distribution of agglomeration disease, examine whether its distribution is statistically significant. Local clusters were investigated using Kulldorff's scan statistic approach. The result reveals that the epidemic mainly gathered in the western part of Africa near north Atlantic with obvious regional distribution. For the current epidemic, we have found areas in high incidence of EVD by means of spatial cluster analysis.
NASA Astrophysics Data System (ADS)
Brizzi, S.; Sandri, L.; Funiciello, F.; Corbi, F.; Piromallo, C.; Heuret, A.
2018-03-01
The observed maximum magnitude of subduction megathrust earthquakes is highly variable worldwide. One key question is which conditions, if any, favor the occurrence of giant earthquakes (Mw ≥ 8.5). Here we carry out a multivariate statistical study in order to investigate the factors affecting the maximum magnitude of subduction megathrust earthquakes. We find that the trench-parallel extent of subduction zones and the thickness of trench sediments provide the largest discriminating capability between subduction zones that have experienced giant earthquakes and those having significantly lower maximum magnitude. Monte Carlo simulations show that the observed spatial distribution of giant earthquakes cannot be explained by pure chance to a statistically significant level. We suggest that the combination of a long subduction zone with thick trench sediments likely promotes a great lateral rupture propagation, characteristic of almost all giant earthquakes.
Spatio-Temporal Patterns of Barmah Forest Virus Disease in Queensland, Australia
Naish, Suchithra; Hu, Wenbiao; Mengersen, Kerrie; Tong, Shilu
2011-01-01
Background Barmah Forest virus (BFV) disease is a common and wide-spread mosquito-borne disease in Australia. This study investigated the spatio-temporal patterns of BFV disease in Queensland, Australia using geographical information system (GIS) tools and geostatistical analysis. Methods/Principal Findings We calculated the incidence rates and standardised incidence rates of BFV disease. Moran's I statistic was used to assess the spatial autocorrelation of BFV incidences. Spatial dynamics of BFV disease was examined using semi-variogram analysis. Interpolation techniques were applied to visualise and display the spatial distribution of BFV disease in statistical local areas (SLAs) throughout Queensland. Mapping of BFV disease by SLAs reveals the presence of substantial spatio-temporal variation over time. Statistically significant differences in BFV incidence rates were identified among age groups (χ2 = 7587, df = 7327,p<0.01). There was a significant positive spatial autocorrelation of BFV incidence for all four periods, with the Moran's I statistic ranging from 0.1506 to 0.2901 (p<0.01). Semi-variogram analysis and smoothed maps created from interpolation techniques indicate that the pattern of spatial autocorrelation was not homogeneous across the state. Conclusions/Significance This is the first study to examine spatial and temporal variation in the incidence rates of BFV disease across Queensland using GIS and geostatistics. The BFV transmission varied with age and gender, which may be due to exposure rates or behavioural risk factors. There are differences in the spatio-temporal patterns of BFV disease which may be related to local socio-ecological and environmental factors. These research findings may have implications in the BFV disease control and prevention programs in Queensland. PMID:22022430
Weather and childbirth: A further search for relationships
NASA Astrophysics Data System (ADS)
Driscoll, Dennis M.
1995-09-01
Previous attempts to find relationships between weather and parturition (childbirth) and its onset (the beginning of labor pains) have revealed, firstly, limited but statistically significant relationships between weather conditions much colder than the day before, with high winds and low pressure, and increased onsets; and secondly, increased numbers of childbirths during periods of atmospheric pressure rise (highly statistically significant). To test these findings, this study examined weather data coincident childbirth data from a hospital at Bryan-College Station, Texas (for a period of 30 cool months from 1987 to 1992). Tests for (1) days of cold fronts, (2) a day before and a day after the cold front, (3) days with large temperature increases, and (4) decreases from the day before revealed no relationship with mean daily rate of onset. Cold days with high winds and low pressure had significantly fewer onsets, a result that is the opposite of previous findings. The postulated relationship between periods of pressure rise and increased birth frequency was negative, i.e., significantly fewer births occurred at those times — again, the opposite of the apparent occurrence in an earlier study. The coincidence of diurnal variations in both atmospheric pressure and frequency of childbirths, was shown to account for fairly strong negative associations between the two variables. This same reasoning might explain the positive association found in an earlier study. A comparison has been made between childbirth and onset as the response variable, and the advantage is emphasized of using data from women whose labor is not induced.
JIANG, QUAN; ZHANG, YUAN; CHEN, JIAN; ZHANG, YUN-XIAO; HE, ZHU
2014-01-01
The aim of this study was to investigate the diagnostic value of the Virtual Touch™ tissue quantification (VTQ) and elastosonography technologies in benign and malignant breast tumors. Routine preoperative ultrasound, elastosonography and VTQ examinations were performed on 86 patients with breast lesions. The elastosonography score and VTQ speed grouping of each lesion were measured and compared with the pathological findings. The difference in the elastosonography score between the benign and malignant breast tumors was statistically significant (P<0.05). The detection rate for an elastosonography score of 1–3 points in benign tumors was 68.09% and that for an elastosonography score of 4–5 points in malignant tumors was 82.05%. The difference in VTQ speed values between the benign and malignant tumors was also statistically significant (P<0.05). In addition, the diagnostic accuracy of conventional ultrasound, elastosonography, VTQ technology and the combined methods showed statistically significant differences (P<0.05). The use of the three technologies in combination significantly improved the diagnostic accuracy to 91.86%. In conclusion, the combination of conventional ultrasound, elastosonography and VTQ technology can significantly improve accuracy in the diagnosis of breast cancer. PMID:25187797
Prediction of phenotypes of missense mutations in human proteins from biological assemblies.
Wei, Qiong; Xu, Qifang; Dunbrack, Roland L
2013-02-01
Single nucleotide polymorphisms (SNPs) are the most frequent variation in the human genome. Nonsynonymous SNPs that lead to missense mutations can be neutral or deleterious, and several computational methods have been presented that predict the phenotype of human missense mutations. These methods use sequence-based and structure-based features in various combinations, relying on different statistical distributions of these features for deleterious and neutral mutations. One structure-based feature that has not been studied significantly is the accessible surface area within biologically relevant oligomeric assemblies. These assemblies are different from the crystallographic asymmetric unit for more than half of X-ray crystal structures. We find that mutations in the core of proteins or in the interfaces in biological assemblies are significantly more likely to be disease-associated than those on the surface of the biological assemblies. For structures with more than one protein in the biological assembly (whether the same sequence or different), we find the accessible surface area from biological assemblies provides a statistically significant improvement in prediction over the accessible surface area of monomers from protein crystal structures (P = 6e-5). When adding this information to sequence-based features such as the difference between wildtype and mutant position-specific profile scores, the improvement from biological assemblies is statistically significant but much smaller (P = 0.018). Combining this information with sequence-based features in a support vector machine leads to 82% accuracy on a balanced dataset of 50% disease-associated mutations from SwissVar and 50% neutral mutations from human/primate sequence differences in orthologous proteins. Copyright © 2012 Wiley Periodicals, Inc.
Sibling Competition & Growth Tradeoffs. Biological vs. Statistical Significance
Kramer, Karen L.; Veile, Amanda; Otárola-Castillo, Erik
2016-01-01
Early childhood growth has many downstream effects on future health and reproduction and is an important measure of offspring quality. While a tradeoff between family size and child growth outcomes is theoretically predicted in high-fertility societies, empirical evidence is mixed. This is often attributed to phenotypic variation in parental condition. However, inconsistent study results may also arise because family size confounds the potentially differential effects that older and younger siblings can have on young children’s growth. Additionally, inconsistent results might reflect that the biological significance associated with different growth trajectories is poorly understood. This paper addresses these concerns by tracking children’s monthly gains in height and weight from weaning to age five in a high fertility Maya community. We predict that: 1) as an aggregate measure family size will not have a major impact on child growth during the post weaning period; 2) competition from young siblings will negatively impact child growth during the post weaning period; 3) however because of their economic value, older siblings will have a negligible effect on young children’s growth. Accounting for parental condition, we use linear mixed models to evaluate the effects that family size, younger and older siblings have on children’s growth. Congruent with our expectations, it is younger siblings who have the most detrimental effect on children’s growth. While we find statistical evidence of a quantity/quality tradeoff effect, the biological significance of these results is negligible in early childhood. Our findings help to resolve why quantity/quality studies have had inconsistent results by showing that sibling competition varies with sibling age composition, not just family size, and that biological significance is distinct from statistical significance. PMID:26938742
Sibling Competition & Growth Tradeoffs. Biological vs. Statistical Significance.
Kramer, Karen L; Veile, Amanda; Otárola-Castillo, Erik
2016-01-01
Early childhood growth has many downstream effects on future health and reproduction and is an important measure of offspring quality. While a tradeoff between family size and child growth outcomes is theoretically predicted in high-fertility societies, empirical evidence is mixed. This is often attributed to phenotypic variation in parental condition. However, inconsistent study results may also arise because family size confounds the potentially differential effects that older and younger siblings can have on young children's growth. Additionally, inconsistent results might reflect that the biological significance associated with different growth trajectories is poorly understood. This paper addresses these concerns by tracking children's monthly gains in height and weight from weaning to age five in a high fertility Maya community. We predict that: 1) as an aggregate measure family size will not have a major impact on child growth during the post weaning period; 2) competition from young siblings will negatively impact child growth during the post weaning period; 3) however because of their economic value, older siblings will have a negligible effect on young children's growth. Accounting for parental condition, we use linear mixed models to evaluate the effects that family size, younger and older siblings have on children's growth. Congruent with our expectations, it is younger siblings who have the most detrimental effect on children's growth. While we find statistical evidence of a quantity/quality tradeoff effect, the biological significance of these results is negligible in early childhood. Our findings help to resolve why quantity/quality studies have had inconsistent results by showing that sibling competition varies with sibling age composition, not just family size, and that biological significance is distinct from statistical significance.
Lee, Hye-Jeong; Uhm, Jae-Sun; Joung, Boyoung; Hong, Yoo Jin; Hur, Jin; Choi, Byoung Wook; Kim, Young Jin
2016-04-01
Myocardial dyskinesia caused by the accessory pathway and related reversible heart failure have been well documented in echocardiographic studies of pediatric patients with Wolff-Parkinson-White (WPW) syndrome. However, the long-term effects of dyskinesia on the myocardium of adult patients have not been studied in depth. The goal of the present study was to evaluate regional myocardial abnormalities on cardiac CT examinations of adult patients with WPW syndrome. Of 74 patients with WPW syndrome who underwent cardiac CT from January 2006 through December 2013, 58 patients (mean [± SD] age, 52.2 ± 12.7 years), 36 (62.1%) of whom were men, were included in the study after the presence of combined cardiac disease was excluded. Two observers blindly evaluated myocardial thickness and attenuation on cardiac CT scans. On the basis of CT findings, patients were classified as having either normal or abnormal findings. We compared the two groups for other clinical findings, including observations from ECG, echocardiography, and electrophysiologic study. Of the 58 patients studied, 16 patients (27.6%) were found to have myocardial abnormalities (i.e., abnormal wall thinning with or without low attenuation). All abnormal findings corresponded with the location of the accessory pathway. Patients with abnormal findings had statistically significantly decreased left ventricular function, compared with patients with normal findings (p < 0.001). The frequency of regional wall motion abnormality was statistically significantly higher in patients with abnormal findings (p = 0.043). However, echocardiography documented structurally normal hearts in all patients. A relatively high frequency (27.6%) of regional myocardial abnormalities was observed on the cardiac CT examinations of adult patients with WPW syndrome. These abnormal findings might reflect the long-term effects of dyskinesia, suggesting irreversible myocardial injury that ultimately causes left ventricular dysfunction.
ERIC Educational Resources Information Center
Sahin, Ismail; Celik, Ismail; Akturk, Ahmet Oguz; Aydin, Mustafa
2013-01-01
This study analyzes the relationships between preservice teachers' technological pedagogical content knowledge (TPACK) and their self-efficacy beliefs in educational Internet use. Findings show statistically significant relationships among the knowledge domains in technology, pedagogy, content, and their intersections. Also, results from the…
Student Effort, Consistency, and Online Performance
ERIC Educational Resources Information Center
Patron, Hilde; Lopez, Salvador
2011-01-01
This paper examines how student effort, consistency, motivation, and marginal learning, influence student grades in an online course. We use data from eleven Microeconomics courses taught online for a total of 212 students. Our findings show that consistency, or less time variation, is a statistically significant explanatory variable, whereas…
29 CFR Section 1607.16 - Definitions.
Code of Federal Regulations, 2010 CFR
2010-07-01
... action are open to users. T. Skill. A present, observable competence to perform a learned psychomoter act... criterion-related validity studies. These conditions include: (1) An adequate sample of persons available for the study to achieve findings of statistical significance; (2) having or being able to obtain a...
Daily Spiritual Experiences and Prosocial Behavior
ERIC Educational Resources Information Center
Einolf, Christopher J.
2013-01-01
This paper examines how the Daily Spiritual Experiences Scale (DSES) relates to range of prosocial behaviors, using a large, nationally representative U.S. data set. It finds that daily spiritual experiences are a statistically and substantively significant predictor of volunteering, charitable giving, and helping individuals one knows personally.…
NASA Astrophysics Data System (ADS)
Malik, Abdul; Brönnimann, Stefan
2016-04-01
The All Indian Summer Monsoon Rainfall (AISMR) is highly important for the livelihood of more than 1 billion people living in the Indian sub-continent. The agriculture of this region is heavily dependent on seasonal (JJAS) monsoon rainfall. An early start or a slight delay of monsoon, or an early withdrawal or prolonged monsoon season may upset the farmer's agricultural plans, can cause significant reduction in crop yield, and hence economic loss. Understanding of AISMR is also vital because it is a part of global atmospheric circulation system. Several studies show that AISMR is influenced by internal climate forcings (ICFs) viz. ENSO, AMO, PDO etc. as well as external climate forcings (ECFs) viz. Greenhouse Gases, volcanic eruptions, and Total Solar Irradiance (TSI). We investigate the influence of ICFs and ECFs on AISMR using recently developed statistical technique called De-trended Partial-Cross-Correlation Analysis (DPCCA). DPCCA can analyse a complex system of several interlinked variables. Often, climatic variables, being cross correlated, are simultaneously tele-connected with several other variables and it is not easy to isolate their intrinsic relationship. In the presence of non-stationarities and background signals the calculated correlation coefficients can be overestimated and erroneous. DPCCA method removes the non-stationarities and partials out the influence of background signals from the variables being cross correlated and thus give a robust estimate of correlation. We have performed the analysis using NOAA Reconstructed SSTs and homogenised instrumental AISMR data set from 1854-1999. By employing the DPCCA method we find that there is a statistically insignificant negative intrinsic relation (by excluding the influence of ICFs, and ECFs except TSI) between AISMR and TSI on decadal to centennial time scale. The ICFs considerably modulate the relation between AISMR and solar activity between 50-80 year time scales and transform this relationship to statistically significant positive. We conclude that the positive relation between AISMR and solar activity, as found by other authors, is due to the combined effect of AMO, PDO and multi-decadal ENSO variability on AISMR. The solar activity influences the ICFs and this influence is then transmitted to AISMR. Further, we find that there is statistically positive intrinsic relation between AISMR and AMO from 26 to 100 year time scales which is modulated by ICFs (PDO, ENSO) and ECFs. PDO, ENSO, and solar activity weaken this intrinsic relationship whereas the combined effect of ECFc (solar activity, volcanic eruptions, CO2, & tropospheric aerosol optical depth) results in strengthening of this relationship from 70 to 100 year time scales. There is a negative intrinsic relation between AISMR and PDO which is not statistically significant at any time scale. However this relationship becomes statistically significant only in the presence of combined effect of North Atlantic SSTs and ENSO (4-39 year time scale) and individual effect of TSI (3-26 year time scale) on AISMR. We also find that there is statistical significant negative relationship between AISMR and ENSO on inter-annual to centennial time scale and the strength of this relationship is modulated by solar activity from 3 to 40 year time scale.
Kennedy, Chinaro; Lordo, Robert; Sucosky, Marissa Scalia; Boehm, Rona; Brown, Mary Jean
2016-01-01
Despite significant progress made in recent decades in preventing childhood lead poisoning in the United States through the control or elimination of lead sources in the environment, it continues to be an issue in many communities, primarily in low-income communities with a large percentage of deteriorating housing built before the elimination of lead in residential paint. The purpose of this study is to determine whether state laws aimed at preventing childhood lead poisoning are also effective in preventing recurring lead poisoning among children previously poisoned. An evaluation was conducted to determine whether laws in two representative states, Massachusetts and Ohio, have been effective in preventing recurrent lead poisoning among children less than 72 months of age previously poisoned, compared to a representative state (Mississippi) which at the time of the study had yet to develop legislation to prevent childhood lead poisoning. Compared to no legislation, unadjusted estimates showed children less than 72 months old, living in Massachusetts, previously identified as being lead poisoned, were 73% less likely to develop recurrent lead poisoning. However, this statistically significant association did not remain after controlling for other confounding variables. We did not find such a significant association when analyzing data from Ohio. While findings from unadjusted estimates indicated that state lead laws such as those in Massachusetts may be effective at preventing recurrent lead poisoning among young children, small numbers may have attenuated the power to obtain statistical significance during multivariate analysis. Our findings did not provide evidence that state lead laws, such as those in Ohio, were effective in preventing recurrent lead poisoning among young children. Further studies may be needed to confirm these findings. Published by Elsevier GmbH.
Kennedy, Chinaro; Lordo, Robert; Sucosky, Marissa Scalia; Boehm, Rona; Brown, Mary Jean
2016-01-01
Background Despite significant progress made in recent decades in preventing childhood lead poisoning in the United States through the control or elimination of lead sources in the environment, it continues to be an issue in many communities, primarily in low-income communities with a large percentage of deteriorating housing built before the elimination of lead in residential paint. The purpose of this study is to determine whether state laws aimed at preventing childhood lead poisoning are also effective in preventing recurring lead poisoning among children previously poisoned. Methods An evaluation was conducted to determine whether laws in two representative states, Massachusetts and Ohio, have been effective in preventing recurrent lead poisoning among children less than 72 months of age previously poisoned, compared to a representative state (Mississippi) which at the time of the study had yet to develop legislation to prevent childhood lead poisoning. Results Compared to no legislation, unadjusted estimates showed children less than 72 months old, living in Massachusetts, previously identified as being lead poisoned, were 73% less likely to develop recurrent lead poisoning. However, this statistically significant association did not remain after controlling for other confounding variables. We did not find such a significant association when analyzing data from Ohio. Conclusions While findings from unadjusted estimates indicated that state lead laws such as those in Massachusetts may be effective at preventing recurrent lead poisoning among young children, small numbers may have attenuated the power to obtain statistical significance during multivariate analysis. Our findings did not provide evidence that state lead laws, such as those in Ohio, were effective in preventing recurrent lead poisoning among young children. Further studies may be needed to confirm these findings. PMID:26472219
Evaluation of NMME temperature and precipitation bias and forecast skill for South Asia
NASA Astrophysics Data System (ADS)
Cash, Benjamin A.; Manganello, Julia V.; Kinter, James L.
2017-08-01
Systematic error and forecast skill for temperature and precipitation in two regions of Southern Asia are investigated using hindcasts initialized May 1 from the North American Multi-Model Ensemble. We focus on two contiguous but geographically and dynamically diverse regions: the Extended Indian Monsoon Rainfall (70-100E, 10-30 N) and the nearby mountainous area of Pakistan and Afghanistan (60-75E, 23-39 N). Forecast skill is assessed using the Sign test framework, a rigorous statistical method that can be applied to non-Gaussian variables such as precipitation and to different ensemble sizes without introducing bias. We find that models show significant systematic error in both precipitation and temperature for both regions. The multi-model ensemble mean (MMEM) consistently yields the lowest systematic error and the highest forecast skill for both regions and variables. However, we also find that the MMEM consistently provides a statistically significant increase in skill over climatology only in the first month of the forecast. While the MMEM tends to provide higher overall skill than climatology later in the forecast, the differences are not significant at the 95% level. We also find that MMEMs constructed with a relatively small number of ensemble members per model can equal or outperform MMEMs constructed with more members in skill. This suggests some ensemble members either provide no contribution to overall skill or even detract from it.
Pulmonary involvement in rheumatoid arthritis: multidetector computed tomography findings.
Yuksekkaya, Ruken; Celikyay, Fatih; Yilmaz, Ayse; Arslan, Sule; Inanir, Ahmet; Inonu, Handan; Deniz, Caglar
2013-12-01
Pulmonary involvement in rheumatoid arthritis (RA) is common and encompasses a large spectrum of disease with different treatment options and prognoses. Therefore, assessment of these patients with multidetector computed tomography (MDCT) is vital. To evaluate the MDCT pulmonary findings of patients with RA and to compare these findings with the clinical status. Chest MDCT scans of 85 patients with RA between 2006-2012 were assessed. One patient with a pulmonary infection was excluded from the study. MDCT findings and distribution of the CT findings were examined, and patients were classified according to the predominant CT pattern. The pulmonary function test (PFT) results and categories, demographic characteristics, and clinical status of some of the patients for whom the results were obtained were evaluated, and the CT findings, PFT results, demographic characteristics, and clinical status were compared. The study group consisted of 20 men (mean age, 58.1 years ± 13.1; range, 15-77 years) and 64 women (mean age, 55.3 years ± 11.5; range, 30-84 years). The most frequent findings were nodules (78.6%) and pleural thickening (48.8%). The most common CT patterns were follicular bronchiolitis (FB) in 28 (33.3%) patients and nodular disease (ND) in 12 (14.3%) others. There was no statistically significant difference between the CT findings and PFT results, and no statistically significant difference was noted in the CT findings between symptomatic and asymptomatic patients. In addition, there were some patients who exhibited no symptoms and/or had abnormal PFT results but had abnormal CT findings. Rheumatoid arthritis is associated with a high frequency of CT findings and CT patterns, with nodules and pleural thickening being the most common CT findings and FB and ND being the most common CT patterns. MDCT identification of patients with RA may be helpful in the evaluation of pulmonary disease, even in patients without symptoms and PFT abnormalities.
Lewis, Ruth A; Williams, Nefyn H; Sutton, Alex J; Burton, Kim; Din, Nafees Ud; Matar, Hosam E; Hendry, Maggie; Phillips, Ceri J; Nafees, Sadia; Fitzsimmons, Deborah; Rickard, Ian; Wilkinson, Clare
2015-06-01
There are numerous treatment approaches for sciatica. Previous systematic reviews have not compared all these strategies together. To compare the clinical effectiveness of different treatment strategies for sciatica simultaneously. Systematic review and network meta-analysis. We searched 28 electronic databases and online trial registries, along with bibliographies of previous reviews for comparative studies evaluating any intervention to treat sciatica in adults, with outcome data on global effect or pain intensity. Network meta-analysis methods were used to simultaneously compare all treatment strategies and allow indirect comparisons of treatments between studies. The study was funded by the UK National Institute for Health Research Health Technology Assessment program; there are no potential conflict of interests. We identified 122 relevant studies; 90 were randomized controlled trials (RCTs) or quasi-RCTs. Interventions were grouped into 21 treatment strategies. Internal and external validity of included studies was very low. For overall recovery as the outcome, compared with inactive control or conventional care, there was a statistically significant improvement following disc surgery, epidural injections, nonopioid analgesia, manipulation, and acupuncture. Traction, percutaneous discectomy, and exercise therapy were significantly inferior to epidural injections or surgery. For pain as the outcome, epidural injections and biological agents were significantly better than inactive control, but similar findings for disc surgery were not statistically significant. Biological agents were significantly better for pain reduction than bed rest, nonopioids, and opioids. Opioids, education/advice alone, bed rest, and percutaneous discectomy were inferior to most other treatment strategies; although these findings represented large effects, they were statistically equivocal. For the first time, many different treatment strategies for sciatica have been compared in the same systematic review and meta-analysis. This approach has provided new data to assist shared decision-making. The findings support the effectiveness of nonopioid medication, epidural injections, and disc surgery. They also suggest that spinal manipulation, acupuncture, and experimental treatments, such as anti-inflammatory biological agents, may be considered. The findings do not provide support for the effectiveness of opioid analgesia, bed rest, exercise therapy, education/advice (when used alone), percutaneous discectomy, or traction. The issue of how best to estimate the effectiveness of treatment approaches according to their order within a sequential treatment pathway remains an important challenge. Copyright © 2015 Elsevier Inc. All rights reserved.
Asymptotic Linear Spectral Statistics for Spiked Hermitian Random Matrices
NASA Astrophysics Data System (ADS)
Passemier, Damien; McKay, Matthew R.; Chen, Yang
2015-07-01
Using the Coulomb Fluid method, this paper derives central limit theorems (CLTs) for linear spectral statistics of three "spiked" Hermitian random matrix ensembles. These include Johnstone's spiked model (i.e., central Wishart with spiked correlation), non-central Wishart with rank-one non-centrality, and a related class of non-central matrices. For a generic linear statistic, we derive simple and explicit CLT expressions as the matrix dimensions grow large. For all three ensembles under consideration, we find that the primary effect of the spike is to introduce an correction term to the asymptotic mean of the linear spectral statistic, which we characterize with simple formulas. The utility of our proposed framework is demonstrated through application to three different linear statistics problems: the classical likelihood ratio test for a population covariance, the capacity analysis of multi-antenna wireless communication systems with a line-of-sight transmission path, and a classical multiple sample significance testing problem.
Saadati, Farzaneh; Ahmad Tarmizi, Rohani
2015-01-01
Because students’ ability to use statistics, which is mathematical in nature, is one of the concerns of educators, embedding within an e-learning system the pedagogical characteristics of learning is ‘value added’ because it facilitates the conventional method of learning mathematics. Many researchers emphasize the effectiveness of cognitive apprenticeship in learning and problem solving in the workplace. In a cognitive apprenticeship learning model, skills are learned within a community of practitioners through observation of modelling and then practice plus coaching. This study utilized an internet-based Cognitive Apprenticeship Model (i-CAM) in three phases and evaluated its effectiveness for improving statistics problem-solving performance among postgraduate students. The results showed that, when compared to the conventional mathematics learning model, the i-CAM could significantly promote students’ problem-solving performance at the end of each phase. In addition, the combination of the differences in students' test scores were considered to be statistically significant after controlling for the pre-test scores. The findings conveyed in this paper confirmed the considerable value of i-CAM in the improvement of statistics learning for non-specialized postgraduate students. PMID:26132553
Analysis of the sleep quality of elderly people using biomedical signals.
Moreno-Alsasua, L; Garcia-Zapirain, B; Mendez-Zorrilla, A
2015-01-01
This paper presents a technical solution that analyses sleep signals captured by biomedical sensors to find possible disorders during rest. Specifically, the method evaluates electrooculogram (EOG) signals, skin conductance (GSR), air flow (AS), and body temperature. Next, a quantitative sleep quality analysis determines significant changes in the biological signals, and any similarities between them in a given time period. Filtering techniques such as the Fourier transform method and IIR filters process the signal and identify significant variations. Once these changes have been identified, all significant data is compared and a quantitative and statistical analysis is carried out to determine the level of a person's rest. To evaluate the correlation and significant differences, a statistical analysis has been calculated showing correlation between EOG and AS signals (p=0,005), EOG, and GSR signals (p=0,037) and, finally, the EOG and Body temperature (p=0,04). Doctors could use this information to monitor changes within a patient.
Azizollah, Arbabisarjou; Abolghasem, Farhang; Amin, Dadgar Mohammad
2016-01-01
Background and Objective: Organizations effort is to achieve a common goal. There are many constructs needed for organizations. Organizational culture and organizational commitment are special concepts in management. The objective of the current research is to study the relationship between organizational culture and organizational commitment among the personnel of Zahedan University of Medical Sciences. Materials and Methods: This is a descriptive- correlational study. The statistical population was whole tenured staff of Zahedan University of Medical Sciences that worked for this organization in 2012-2013. Random sampling method was used and 165 samples were chosen. Two standardized questionnaires of the organizational culture (Schein, 1984) and organizational commitment (Meyer & Allen, 2002) were applied. The face and construct validity of the questionnaires were approved by the lecturers of Management and experts. Reliability of questionnaires of the organizational culture and organizational commitment were 0.89 and 0.88 respectively, by Cronbach’s Alpha coefficient. All statistical calculations performed using Statistical Package for the Social Sciences version 21.0 (SPSS Inc., Chicago, IL, USA). The level of significance was set at P<0.05. Findings: The findings of the study showed that there was a significant relationship between organizational culture and organizational commitment (P value=0.027). Also, the results showed that there was a significant relation between organizational culture and affective commitment (P-value=0.009), organizational culture and continuance commitment (P-value=0.009), and organizational culture and normative commitment (P-value=0.009). PMID:26925884
Time series, periodograms, and significance
NASA Astrophysics Data System (ADS)
Hernandez, G.
1999-05-01
The geophysical literature shows a wide and conflicting usage of methods employed to extract meaningful information on coherent oscillations from measurements. This makes it difficult, if not impossible, to relate the findings reported by different authors. Therefore, we have undertaken a critical investigation of the tests and methodology used for determining the presence of statistically significant coherent oscillations in periodograms derived from time series. Statistical significance tests are only valid when performed on the independent frequencies present in a measurement. Both the number of possible independent frequencies in a periodogram and the significance tests are determined by the number of degrees of freedom, which is the number of true independent measurements, present in the time series, rather than the number of sample points in the measurement. The number of degrees of freedom is an intrinsic property of the data, and it must be determined from the serial coherence of the time series. As part of this investigation, a detailed study has been performed which clearly illustrates the deleterious effects that the apparently innocent and commonly used processes of filtering, de-trending, and tapering of data have on periodogram analysis and the consequent difficulties in the interpretation of the statistical significance thus derived. For the sake of clarity, a specific example of actual field measurements containing unevenly-spaced measurements, gaps, etc., as well as synthetic examples, have been used to illustrate the periodogram approach, and pitfalls, leading to the (statistical) significance tests for the presence of coherent oscillations. Among the insights of this investigation are: (1) the concept of a time series being (statistically) band limited by its own serial coherence and thus having a critical sampling rate which defines one of the necessary requirements for the proper statistical design of an experiment; (2) the design of a critical test for the maximum number of significant frequencies which can be used to describe a time series, while retaining intact the variance of the test sample; (3) a demonstration of the unnecessary difficulties that manipulation of the data brings into the statistical significance interpretation of said data; and (4) the resolution and correction of the apparent discrepancy in significance results obtained by the use of the conventional Lomb-Scargle significance test, when compared with the long-standing Schuster-Walker and Fisher tests.
Transport Coefficients from Large Deviation Functions
NASA Astrophysics Data System (ADS)
Gao, Chloe; Limmer, David
2017-10-01
We describe a method for computing transport coefficients from the direct evaluation of large deviation function. This method is general, relying on only equilibrium fluctuations, and is statistically efficient, employing trajectory based importance sampling. Equilibrium fluctuations of molecular currents are characterized by their large deviation functions, which is a scaled cumulant generating function analogous to the free energy. A diffusion Monte Carlo algorithm is used to evaluate the large deviation functions, from which arbitrary transport coefficients are derivable. We find significant statistical improvement over traditional Green-Kubo based calculations. The systematic and statistical errors of this method are analyzed in the context of specific transport coefficient calculations, including the shear viscosity, interfacial friction coefficient, and thermal conductivity.
Occupational Injury and Illness Surveillance: Conceptual Filters Explain Underreporting
Azaroff, Lenore S.; Levenstein, Charles; Wegman, David H.
2002-01-01
Occupational health surveillance data are key to effective intervention. However, the US Bureau of Labor Statistics survey significantly underestimates the incidence of work-related injuries and illnesses. Researchers supplement these statistics with data from other systems not designed for surveillance. The authors apply the filter model of Webb et al. to underreporting by the Bureau of Labor Statistics, workers’ compensation wage-replacement documents, physician reporting systems, and medical records of treatment charged to workers’ compensation. Mechanisms are described for the loss of cases at successive steps of documentation. Empirical findings indicate that workers repeatedly risk adverse consequences for attempting to complete these steps, while systems for ensuring their completion are weak or absent. PMID:12197968
Statistical learning and selective inference.
Taylor, Jonathan; Tibshirani, Robert J
2015-06-23
We describe the problem of "selective inference." This addresses the following challenge: Having mined a set of data to find potential associations, how do we properly assess the strength of these associations? The fact that we have "cherry-picked"--searched for the strongest associations--means that we must set a higher bar for declaring significant the associations that we see. This challenge becomes more important in the era of big data and complex statistical modeling. The cherry tree (dataset) can be very large and the tools for cherry picking (statistical learning methods) are now very sophisticated. We describe some recent new developments in selective inference and illustrate their use in forward stepwise regression, the lasso, and principal components analysis.
Infants with Williams syndrome detect statistical regularities in continuous speech.
Cashon, Cara H; Ha, Oh-Ryeong; Graf Estes, Katharine; Saffran, Jenny R; Mervis, Carolyn B
2016-09-01
Williams syndrome (WS) is a rare genetic disorder associated with delays in language and cognitive development. The reasons for the language delay are unknown. Statistical learning is a domain-general mechanism recruited for early language acquisition. In the present study, we investigated whether infants with WS were able to detect the statistical structure in continuous speech. Eighteen 8- to 20-month-olds with WS were familiarized with 2min of a continuous stream of synthesized nonsense words; the statistical structure of the speech was the only cue to word boundaries. They were tested on their ability to discriminate statistically-defined "words" and "part-words" (which crossed word boundaries) in the artificial language. Despite significant cognitive and language delays, infants with WS were able to detect the statistical regularities in the speech stream. These findings suggest that an inability to track the statistical properties of speech is unlikely to be the primary basis for the delays in the onset of language observed in infants with WS. These results provide the first evidence of statistical learning by infants with developmental delays. Copyright © 2016 Elsevier B.V. All rights reserved.
Postpartum sexual abstinence, breastfeeding, and childspacing, among Yoruba women in urban Nigeria.
Feyisetan, B J
1990-01-01
This paper examines the extent to which the traditional practice of sexual abstinence during lactation has broken down among Yoruba women residents in urban areas. The first major finding is that there is a gradual erosion of the tradition, and the dominant factors of modernization are education of the woman and the use of contraception. The second major finding is that the breakdown of postpartum sexual taboos has statistically significant negative consequences on duration of lactation, although the negative impact of woman's education is greater. The third major finding is that duration of breastfeeding reduces birth interval significantly only when it is less than 15 months, and that both durations of breastfeeding and birth intervals have declined over time. The first two findings suggest further reductions in the proportion of women who abstain from sexual relations during lactation and in durations of breastfeeding as more women become more educated. Significant declines in birth intervals may follow soon after.
Ganna, Andrea; Lee, Donghwan; Ingelsson, Erik; Pawitan, Yudi
2015-07-01
It is common and advised practice in biomedical research to validate experimental or observational findings in a population different from the one where the findings were initially assessed. This practice increases the generalizability of the results and decreases the likelihood of reporting false-positive findings. Validation becomes critical when dealing with high-throughput experiments, where the large number of tests increases the chance to observe false-positive results. In this article, we review common approaches to determine statistical thresholds for validation and describe the factors influencing the proportion of significant findings from a 'training' sample that are replicated in a 'validation' sample. We refer to this proportion as rediscovery rate (RDR). In high-throughput studies, the RDR is a function of false-positive rate and power in both the training and validation samples. We illustrate the application of the RDR using simulated data and real data examples from metabolomics experiments. We further describe an online tool to calculate the RDR using t-statistics. We foresee two main applications. First, if the validation study has not yet been collected, the RDR can be used to decide the optimal combination between the proportion of findings taken to validation and the size of the validation study. Secondly, if a validation study has already been done, the RDR estimated using the training data can be compared with the observed RDR from the validation data; hence, the success of the validation study can be assessed. © The Author 2014. Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.
Extra-Curricular Inequality. Research Brief. Edition 1
ERIC Educational Resources Information Center
Sutton Trust, 2014
2014-01-01
This Research Briefing analyses Office for National Statistics data and finds children from the most advantaged households benefit from significantly more spending on extra-curricular activities and private tutoring than their poorer peers. The brief also includes the Trust's annual polling on private tuition and new polling on parents and…
School Violence: The Role of Parental and Community Involvement
ERIC Educational Resources Information Center
Lesneskie, Eric; Block, Steven
2017-01-01
This study utilizes the School Survey on Crime and Safety to identify variables that predict lower levels of violence from four domains: school security, school climate, parental involvement, and community involvement. Negative binomial regression was performed and the findings indicate that statistically significant results come from all four…
Food Service Manager Certification: An Evaluation of Its Impact.
ERIC Educational Resources Information Center
Wright, Jerry; Fuen, Lindson
1986-01-01
Discusses a study which sought to determine if food service management training and certification resulted in more sanitary operations. Findings from site inspections, pre/post tests, and attitude surveys indicated that the program did not produce statistically significant differences between control and study groups but that improvements in…
Understanding and Reducing Stress in the Superintendency
ERIC Educational Resources Information Center
Hawk, Nita; Martin, Barbara
2011-01-01
This study examined the ways and to what degree, if any, school superintendents perceive stress and what, if any, coping mechanisms were engaged. Study findings revealed that there is a statistical difference between the types of coping mechanisms utilized and effectiveness between male and female superintendents. While no significant difference…
The Impact of Workplace Learning on Job Satisfaction in Small US Commercial Banks
ERIC Educational Resources Information Center
Rowden, Robert W.; Conine, Clyde T., Jr.
2005-01-01
Purpose: This study aims to examine workplace learning and job satisfaction in small, commercial US banks. Design/methodology/approach: Survey data collection with correlational procedure. Findings: The study found a statistically significant relationship between the workplace learning variables and the job satisfaction variables. Research…
An Analysis of Teacher Sorting in Secondary Special Education and Alternative Schools
ERIC Educational Resources Information Center
Mason-Williams, Loretta; Gagnon, Joseph Calvin
2017-01-01
This study provides nationally representative information about the qualifications and preparation of secondary content and special education teachers in special education and alternative school settings, as compared with teachers in regular schools. Findings demonstrate that a statistically significant relationship did not exist between school…
Ethical Reasoning Instruction in Non-Ethics Business Courses: A Non-Intrusive Approach
ERIC Educational Resources Information Center
Wilhelm, William J.
2010-01-01
This article discusses four confirmatory studies designed to corroborate findings from prior developmental research which yielded statistically significant improvements in student moral reasoning when specific instructional strategies and content materials were utilized in non-ethics business courses by instructors not formally trained in business…
An Investigation of School Counselor Self-Efficacy with English Language Learners
ERIC Educational Resources Information Center
Johnson, Leonissa V.; Ziomek-Daigle, Jolie; Haskins, Natoya Hill; Paisley, Pamela O.
2017-01-01
This exploratory quantitative study described school counselors' self-efficacy with English language learners. Findings suggest that school counselors with exposure to and experiences with English language learners have higher levels of self-efficacy. Statistically significant and practical differences in self-efficacy were apparent by race, U.S.…
ERIC Educational Resources Information Center
Doss, Daniel; Lackey, Hilliard; McElreath, David; Gokaraju, Balakrishna; Tesiero, Raymond; Jones, Don; Lusk, Glenna
2017-01-01
This study uses multiple regressions to examine campus safety and campus security from the perspective of societal crime that occurs external to an institution of higher education versus institutional enrollment. The findings herein showed one statistically significant outcome involving the crime of aggravated assault. Student affairs and other…
The Benefits of Cross-Racial Engagement on the College Satisfaction of Student-Athletes
ERIC Educational Resources Information Center
Jones, Willis A.; Liu, Keke; Bell, Lydia F.
2017-01-01
Using nationally representative data from the 2010 NCAA Growth, Opportunities, Aspirations and Learning of Students in college (GOALS) survey, this study examines whether student-athletes' cross-racial interactions correlate with their college satisfaction. Our findings suggest a small but statistically significant correlation between cross-racial…
Effect Sizes in Gifted Education Research
ERIC Educational Resources Information Center
Gentry, Marcia; Peters, Scott J.
2009-01-01
Recent calls for reporting and interpreting effect sizes have been numerous, with the 5th edition of the "Publication Manual of the American Psychological Association" (2001) calling for the inclusion of effect sizes to interpret quantitative findings. Many top journals have required that effect sizes accompany claims of statistical significance.…
Content and Citation Analyses of "Public Relations Review."
ERIC Educational Resources Information Center
Morton, Linda P.; Lin, Li-Yun
1995-01-01
Analyzes 161 cited and 177 uncited articles published in "Public Relations Review" (1975-93) to determine if 3 independent variables--research methods, type of statistics, and topics--influenced whether or not articles were cited in other research articles. Finds significant differences between quantitative and qualitative research methods but not…
Non-Cognitive Factor Relationships to Hybrid Doctoral Student Self-Efficacy
ERIC Educational Resources Information Center
Egbert, Jessica Dalby; Gomez, Frank; Li, Wenling; Pennington, Sandra L.
2015-01-01
Statistical analysis of data gathered from 139 healthcare doctoral students revealed three key findings regarding non-cognitive factor relationships to hybrid doctoral student self-efficacy between online (web-based) and on-campus course components. First, student experiences significantly differed between online and on-campus course components…
Hair Mineral Analysis and Disruptive Behavior in Clinically Normal Young Men.
ERIC Educational Resources Information Center
Struempler, Richard E.; And Others
1985-01-01
Forty young navy recruits were selected for hair mineral analysis on the basis of three criteria: mental test scores, demerits during training, and premature discharge from the navy. Statistical analysis revealed several significant relationships between behavioral criteria and mineral measures. Findings confirmed, in a nonclinical sample, hair…
Seo, Jong-Geun; Kang, Kyunghun; Jung, Ji-Young; Park, Sung-Pa; Lee, Maan-Gee; Lee, Ho-Won
2014-12-01
In this pilot study, we analyzed relationships between quantitative EEG measurements and clinical parameters in idiopathic normal pressure hydrocephalus patients, along with differences in these quantitative EEG markers between cerebrospinal fluid tap test responders and nonresponders. Twenty-six idiopathic normal pressure hydrocephalus patients (9 cerebrospinal fluid tap test responders and 17 cerebrospinal fluid tap test nonresponders) constituted the final group for analysis. The resting EEG was recorded and relative powers were computed for seven frequency bands. Cerebrospinal fluid tap test nonresponders, when compared with responders, showed a statistically significant increase in alpha2 band power at the right frontal and centrotemporal regions. Higher delta2 band powers in the frontal, central, parietal, and occipital regions and lower alpha1 band powers in the right temporal region significantly correlated with poorer cognitive performance. Higher theta1 band powers in the left parietal and occipital regions significantly correlated with gait dysfunction. And higher delta1 band powers in the right frontal regions significantly correlated with urinary disturbance. Our findings may encourage further research using quantitative EEG in patients with ventriculomegaly as a potential electrophysiological marker for predicting cerebrospinal fluid tap test responders. This study additionally suggests that the delta, theta, and alpha bands are statistically correlated with the severity of symptoms in idiopathic normal pressure hydrocephalus patients.
Cakmakci, Emin; Ucan, Berna; Colak, Bayram; Cinar, Hasibe Gokçe
2014-09-01
The purpose of this study was to find out whether transabdominal sonography may have a predictive role for detection of antral gastritis and Helicobacter pylori infection in the antrum. A total of 108 patients and 54 control participants were allocated into 3 groups: group 1, controls without any symptoms or findings of antral gastritis and H pylori infection; group 2, patients with symptoms and endoscopic findings consistent with gastritis in the absence of documented H pylori infection; and group 3, patients with symptoms and endoscopic findings consistent with gastritis and documented H pylori infection. These groups were compared in terms of demographics, antral wall thickness, mucosal layer (together with muscularis mucosa) thickness, and mucosal layer-to-antral wall thickness ratio. The groups had no statistically significant differences with respect to age, sex, body mass index, and smoking habits. However, it turned out that both antral walls and muscularis mucosa layers were thicker and the mucosal layer-to-antral wall thickness ratio was higher in groups 2 and 3 compared to group 1 (P > .001). In addition, group 3 had statistically significantly thicker antral walls and muscularis mucosa layers and a significantly increased mucosal layer-to-antral wall thickness ratio than group 2 (P < .001). Our results suggest that antral gastritis caused by H pylori infection is associated with characteristic features such as thickening of antral walls and mucosal layers on sonography. These novel clues may be useful in the diagnosis of gastritis, and unnecessary interventions and measures can be avoided in some cases. © 2014 by the American Institute of Ultrasound in Medicine.
Hoover, Kara C; Matsumura, Hirofumi
2008-12-01
We examined nutritional and developmental instability in prehistoric Japan, using data from 49 individuals across 13 archaeological sites. Hypoplasia incidence was used as a measure of nutritional stress, and fluctuating asymmetry (of upper facial breath, orbital breadth, and orbital height) as an indirect assessment of developmental instability. Abundant resources due to a stable climate during the Middle Jomon (5,000-3,000 BP) encouraged population growth, which led to regional cultural homogeneity and complexity. A population crash on Honshu in the Late/Final Jomon (roughly 4,000-2,000 BP) led to regionally divergent subsistence economies and settlement patterns. We find that the nutritional stress was consistent between periods, but developmental instability (DI) decreased in the Late/Final Jomon. While the DI values were not statistically significant, the higher values for Middle Jomon may result from sedentism, social stratification, and differential access to resources. On Hokkaido, Jomon culture persisted until the Okhotsk period (1,000-600 BP), marked by the arrival of immigrants from Sakhalin. Nutritional stress was consistent between Middle and Late/Final Jomon, but DI increased in the Late/Final. Nutritional and developmental instability decreased from Late/Final to Okhotsk, suggesting a positive immigrant effect. We expected to find an association between stress markers due to the synergistic relationship between nutrition and pathology. The data support this hypothesis, but only one finding was statistically significant. While high critical values from small sample sizes place limits on the significance of our results, we find that the impact of environmental and cultural change to prehistoric Japanese populations was minimal. (c) 2008 Wiley-Liss, Inc.
Boccio, Cashen M; Beaver, Kevin M
2017-08-01
There is conflicting evidence regarding the association between adolescent marijuana use and adult intelligence, with some studies suggesting adolescent marijuana use can lead to declines in intelligence. The purpose of this study is to shed additional light on the potential link between marijuana use and changes in intelligence. We employed change scores and ordinary least squares (OLS) analysis to test for associations between marijuana use and changes in intelligence scores from adolescence (ages 12-21) to adulthood (ages 18-26) using data drawn from the National Longitudinal Study of Adolescent to Adult Health. The findings revealed that while a binary measure of marijuana use (ever/never) maintains a statistically significant association with changes in intelligence scores, the effect sizes are relatively small (β=0.043-0.051). Additionally, our findings did not reveal a significant association between cumulative marijuana use and changes in intelligence scores. Taken together, the results suggest that while the binary measure of marijuana use (ever/never) has a statistically significant association with changes in intelligence scores, the binary measure accounts for at most a 1-2 point change in intelligence scores. Copyright © 2017 Elsevier B.V. All rights reserved.
Relationship between Smoking and Outcomes after Cubital Tunnel Release.
Crosby, Nicholas E; Nosrati, Naveed N; Merrell, Greg; Hasting, Hill
2018-04-01
Several studies have drawn a connection between cigarette smoking and cubital tunnel syndrome. One comparison article demonstrated worse outcomes in smokers treated with transmuscular transposition of the ulnar nerve. However, very little is known about the effect that smoking might have on patients who undergo ulnar nerve decompression at the elbow. The purpose of this study is to evaluate the effect of smoking preoperatively on outcomes in patients treated with ulnar nerve decompression. This study used a survey developed from the comparison article with additional questions based on outcome measures from supportive literature. Postoperative improvement was probed, including sensation, strength, and pain scores. A thorough smoking history was obtained. The study spanned a 10-year period. A total of 1,366 surveys were mailed to former patients, and 247 surveys with adequate information were returned. No significant difference was seen in demographics or comorbidities. Patients who smoked preoperatively were found to more likely relate symptoms of pain. Postoperatively, nonsmoking patients generally reported more favorable improvement, though these findings were not statistically significant. This study finds no statistically significant effect of smoking on outcomes after ulnar nerve decompression. Finally, among smokers, there were no differences in outcomes between simple decompression and transposition.
Identifying Patients with Hypertension: A Case for Auditing Electronic Health Record Data
Baus, Adam; Hendryx, Michael; Pollard, Cecil
2012-01-01
Problems in the structure, consistency, and completeness of electronic health record data are barriers to outcomes research, quality improvement, and practice redesign. This nonexperimental retrospective study examines the utility of importing de-identified electronic health record data into an external system to identify patients with and at risk for essential hypertension. We find a statistically significant increase in cases based on combined use of diagnostic and free-text coding (mean = 1,256.1, 95% CI 1,232.3–1,279.7) compared to diagnostic coding alone (mean = 1,174.5, 95% CI 1,150.5—1,198.3). While it is not surprising that significantly more patients are identified when broadening search criteria, the implications are critical for quality of care, the movement toward the National Committee for Quality Assurance's Patient-Centered Medical Home program, and meaningful use of electronic health records. Further, we find a statistically significant increase in potential cases based on the last two or more blood pressure readings greater than or equal to 140/90 mm Hg (mean = 1,353.9, 95% CI 1,329.9—1,377.9). PMID:22737097
Statistical Reviewers Improve Reporting in Biomedical Articles: A Randomized Trial
Cobo, Erik; Selva-O'Callagham, Albert; Ribera, Josep-Maria; Cardellach, Francesc; Dominguez, Ruth; Vilardell, Miquel
2007-01-01
Background Although peer review is widely considered to be the most credible way of selecting manuscripts and improving the quality of accepted papers in scientific journals, there is little evidence to support its use. Our aim was to estimate the effects on manuscript quality of either adding a statistical peer reviewer or suggesting the use of checklists such as CONSORT or STARD to clinical reviewers or both. Methodology and Principal Findings Interventions were defined as 1) the addition of a statistical reviewer to the clinical peer review process, and 2) suggesting reporting guidelines to reviewers; with “no statistical expert” and “no checklist” as controls. The two interventions were crossed in a 2×2 balanced factorial design including original research articles consecutively selected, between May 2004 and March 2005, by the Medicina Clinica (Barc) editorial committee. We randomized manuscripts to minimize differences in terms of baseline quality and type of study (intervention, longitudinal, cross-sectional, others). Sample-size calculations indicated that 100 papers provide an 80% power to test a 55% standardized difference. We specified the main outcome as the increment in quality of papers as measured on the Goodman Scale. Two blinded evaluators rated the quality of manuscripts at initial submission and final post peer review version. Of the 327 manuscripts submitted to the journal, 131 were accepted for further review, and 129 were randomized. Of those, 14 that were lost to follow-up showed no differences in initial quality to the followed-up papers. Hence, 115 were included in the main analysis, with 16 rejected for publication after peer review. 21 (18.3%) of the 115 included papers were interventions, 46 (40.0%) were longitudinal designs, 28 (24.3%) cross-sectional and 20 (17.4%) others. The 16 (13.9%) rejected papers had a significantly lower initial score on the overall Goodman scale than accepted papers (difference 15.0, 95% CI: 4.6–24.4). The effect of suggesting a guideline to the reviewers had no effect on change in overall quality as measured by the Goodman scale (0.9, 95% CI: −0.3–+2.1). The estimated effect of adding a statistical reviewer was 5.5 (95% CI: 4.3–6.7), showing a significant improvement in quality. Conclusions and Significance This prospective randomized study shows the positive effect of adding a statistical reviewer to the field-expert peers in improving manuscript quality. We did not find a statistically significant positive effect by suggesting reviewers use reporting guidelines. PMID:17389922
Communication: Dominance of extreme statistics in a prototype many-body Brownian ratchet.
Hohlfeld, Evan; Geissler, Phillip L
2014-10-28
Many forms of cell motility rely on Brownian ratchet mechanisms that involve multiple stochastic processes. We present a computational and theoretical study of the nonequilibrium statistical dynamics of such a many-body ratchet, in the specific form of a growing polymer gel that pushes a diffusing obstacle. We find that oft-neglected correlations among constituent filaments impact steady-state kinetics and significantly deplete the gel's density within molecular distances of its leading edge. These behaviors are captured quantitatively by a self-consistent theory for extreme fluctuations in filaments' spatial distribution.
Distribution of water quality parameters in Dhemaji district, Assam (India).
Buragohain, Mridul; Bhuyan, Bhabajit; Sarma, H P
2010-07-01
The primary objective of this study is to present a statistically significant water quality database of Dhemaji district, Assam (India) with special reference to pH, fluoride, nitrate, arsenic, iron, sodium and potassium. 25 water samples collected from different locations of five development blocks in Dhemaji district have been studied separately. The implications presented are based on statistical analyses of the raw data. Normal distribution statistics and reliability analysis (correlation and covariance matrix) have been employed to find out the distribution pattern, localisation of data, and other related information. Statistical observations show that all the parameters under investigation exhibit non uniform distribution with a long asymmetric tail either on the right or left side of the median. The width of the third quartile was consistently found to be more than the second quartile for each parameter. Differences among mean, mode and median, significant skewness and kurtosis value indicate that the distribution of various water quality parameters in the study area is widely off normal. Thus, the intrinsic water quality is not encouraging due to unsymmetrical distribution of various water quality parameters in the study area.
Role of sufficient statistics in stochastic thermodynamics and its implication to sensory adaptation
NASA Astrophysics Data System (ADS)
Matsumoto, Takumi; Sagawa, Takahiro
2018-04-01
A sufficient statistic is a significant concept in statistics, which means a probability variable that has sufficient information required for an inference task. We investigate the roles of sufficient statistics and related quantities in stochastic thermodynamics. Specifically, we prove that for general continuous-time bipartite networks, the existence of a sufficient statistic implies that an informational quantity called the sensory capacity takes the maximum. Since the maximal sensory capacity imposes a constraint that the energetic efficiency cannot exceed one-half, our result implies that the existence of a sufficient statistic is inevitably accompanied by energetic dissipation. We also show that, in a particular parameter region of linear Langevin systems there exists the optimal noise intensity at which the sensory capacity, the information-thermodynamic efficiency, and the total entropy production are optimized at the same time. We apply our general result to a model of sensory adaptation of E. coli and find that the sensory capacity is nearly maximal with experimentally realistic parameters.
Forensic 3D Visualization of CT Data Using Cinematic Volume Rendering: A Preliminary Study.
Ebert, Lars C; Schweitzer, Wolf; Gascho, Dominic; Ruder, Thomas D; Flach, Patricia M; Thali, Michael J; Ampanozi, Garyfalia
2017-02-01
The 3D volume-rendering technique (VRT) is commonly used in forensic radiology. Its main function is to explain medical findings to state attorneys, judges, or police representatives. New visualization algorithms permit the generation of almost photorealistic volume renderings of CT datasets. The objective of this study is to present and compare a variety of radiologic findings to illustrate the differences between and the advantages and limitations of the current VRT and the physically based cinematic rendering technique (CRT). Seventy volunteers were shown VRT and CRT reconstructions of 10 different cases. They were asked to mark the findings on the images and rate them in terms of realism and understandability. A total of 48 of the 70 questionnaires were returned and included in the analysis. On the basis of most of the findings presented, CRT appears to be equal or superior to VRT with respect to the realism and understandability of the visualized findings. Overall, in terms of realism, the difference between the techniques was statistically significant (p < 0.05). Most participants perceived the CRT findings to be more understandable than the VRT findings, but that difference was not statistically significant (p > 0.05). CRT, which is similar to conventional VRT, is not primarily intended for diagnostic radiologic image analysis, and therefore it should be used primarily as a tool to deliver visual information in the form of radiologic image reports. Using CRT for forensic visualization might have advantages over using VRT if conveying a high degree of visual realism is of importance. Most of the shortcomings of CRT have to do with the software being an early prototype.
Santosh Kumar, B B; Aruna, D R; Gowda, Vinayak S; Galagali, Sushama R; Prashanthy, R; Navaneetha, H
2013-09-01
Recently, there has been interest in non-mammalian collagen sources such as fish collagen in periodontal regeneration. In the present study, collagen barrier membrane of fish origin was assessed in the treatment of periodontal intrabony defects. Ten systemically healthy chronic periodontitis patients having a paired osseous defect in the mandibular posterior teeth were selected and randomly assigned to receive a collagen membrane (test) or open flap debridement (control) in a split mouth design. Clinical parameters such as Plaque index, Gingival bleeding index, Probing pocket depth, Relative attachment level, and Recession were recorded at baseline, 3, 6, and at 9 months, while radiographic evaluation was done to assess alveolar crestal bone level and percentage of defect fill at 6 and 9 months using autoCAD 2007 software. Student's t test (two-tailed, dependent) was used to find the significance of study parameters on continuous scale. Significance was set at 5% level of significance. Wilcoxon signed rank test was used to find the significance of percentage change of defect fill. The comparison between the two groups did not show any statistically significant differences in the parameters assessed (P > 0.05) but, within each group, clinical parameters showed statistically significant differences from baseline to 9 months (P < 0.05). Within the limits of the study, it can be inferred that no significant differences were found either by using collagen membrane of fish origin or open flap debridement in the treatment of periodontal intrabony defects.
Thomas, Linda S; Stephenson, Nancy; Swanson, Mel; Jesse, D Elizabeth; Brown, Sylvia
2013-12-01
This pilot study was conducted to determine the effectiveness of Healing Touch on anxiety, stress, pain, pain medication usage, and selected physiological measures of hospitalized adults with sickle cell disease experiencing a vaso-occlusive pain episode. Healing Touch sessions were administered for 30 minutes on four consecutive days, and the self-reported data on anxiety, stress, pain, and the selected physiological data were collected while controlling for music and presence. A parallel-group randomized control trial comparing the effects of Healing Touch with Music (HTM) to Attention Control with Music (ACM). Due to the small sample size, there were no statistically significant changes in any between-group comparisons, except for present pain on Day 4 for the ACM group. For both groups, the within-group comparison showed a nonsignificant reduction in physiological parameters, a statistically significant reduction in anxiety and stress for the ACM group after Day 4, and a statistically significant reduction in stress in the HTM group after Days 2 and 4. The pre- to postintervention reductions in present pain were greater in the HTM group across all 4 days, but the only statistically significant within groups findings were in the HTM group (p < .01) on Day 1. Further research is needed.
Gupta, Surya N; Gupta, Vikash S; White, Andrew C
2016-01-01
Intracranial incidental findings on magnetic resonance imaging (MRI) of the brain continue to generate interest in healthy control, research, and clinical subjects. However, in clinical practice, the discovery of incidental findings acts as a “distractor”. This review is based on existing heterogeneous reports, their clinical implications, and how the results of incidental findings influence clinical management. This draws attention to the followings: (1) the prevalence of clinically significant incidental findings is low; (2) there is a lack of a systematic approach to classification; and discusses (3) how to deal with the detected incidental findings based a proposed common clinical profile. Individualized neurological care requires an active discussion regarding the need for neuroimaging. Clinical significance of incidental findings should be decided based on lesion’s neuroradiologic characteristics in the given clinical context. Available evidence suggests that the outcome of an incidentally found “serious lesion in children” is excellent. Future studies of intracranial incidental findings on pediatric brain MRI should be focused on a homogeneous population. The study should address this clinical knowledge based review powered by the statistical analyses. PMID:27610341
Krawczyk, Michał
2015-01-01
In this project I investigate the use and possible misuse of p values in papers published in five (high-ranked) journals in experimental psychology. I use a data set of over 135'000 p values from more than five thousand papers. I inspect (1) the way in which the p values are reported and (2) their distribution. The main findings are following: first, it appears that some authors choose the mode of reporting their results in an arbitrary way. Moreover, they often end up doing it in such a way that makes their findings seem more statistically significant than they really are (which is well known to improve the chances for publication). Specifically, they frequently report p values "just above" significance thresholds directly, whereas other values are reported by means of inequalities (e.g. "p<.1"), they round the p values down more eagerly than up and appear to choose between the significance thresholds and between one- and two-sided tests only after seeing the data. Further, about 9.2% of reported p values are inconsistent with their underlying statistics (e.g. F or t) and it appears that there are "too many" "just significant" values. One interpretation of this is that researchers tend to choose the model or include/discard observations to bring the p value to the right side of the threshold.
Gender interactions and success.
Wiggins, Carla; Peterson, Teri
2004-01-01
Does gender by itself, or does gender's interaction with career variables, better explain the difference between women and men's careers in healthcare management? US healthcare managers were surveyed regarding career and personal experiences. Gender was statistically interacted with explanatory variables. Multiple regression with backwards selection systematically removed non-significant variables. All gender interaction variables were non-significant. Much of the literature proposes that work and career factors impact working women differently than working men. We find that while gender alone is a significant predictor of income, it does not significantly interact with other career variables.
Ogden, Michael W.; Marano, Kristin M.; Jones, Bobbette A.; Morgan, Walter T.; Stiles, Mitchell F.
2015-01-01
Abstract A randomized, multi-center study of adult cigarette smokers switched to tobacco-heating cigarettes, snus or ultra-low machine yield tobacco-burning cigarettes (50/group) for 24 weeks was conducted. Evaluation of biomarkers of biological effect (e.g. inflammation, lipids, hypercoaguable state) indicated that the majority of consistent and statistically significant improvements over time within each group were observed in markers of inflammation. Consistent and statistically significant differences in pairwise comparisons between product groups were not observed. These findings are relevant to the understanding of biomarkers of biological effect related to cigarette smoking as well as the risk continuum across various tobacco products (ClinicalTrials.gov Identifier: NCT02061917). PMID:26525962
A comparison of workload and morbidity recording by partners in a group practice
Carney, T. A.
1980-01-01
A survey was carried out of one year's workload and morbidity recording by three partners in a semi-rural teaching practice. Despite an equal workload of patient contacts there were shown to be statistically significant differences between the partners in the number of return consultations, the sex and age of the patients seen, and in nine diagnostic groups. The statistically significant differences in the latter groups appear to have been caused by variations in policy for recalling patients and the different sex and age groups of the patients consulting the partners, not by diagnostic preferences. A lack of previous experience affected one group. The partners did not find the discussion of these differences to be threatening. PMID:7441620
Carbonaceous particulate matter on the lung surface from adults living in São Paulo, Brazil.
Padovan, Michele Galhardoni; Whitehouse, Abigail; Gouveia, Nelson; Habermann, Mateus; Grigg, Jonathan
2017-01-01
We therefore sought to identify the exposures associated with lung surface in long-term residents of São Paulo, Brazil. Lung surface carbon were analyzed in 72 autopsy specimens by image analysis. Smoking history, measured PM10 nearest to the home, distance to main road, and distance-weighted traffic density were used as exposure variables. Data are summarized as median (IQR), and compared by Mann Whitney Test, with correlations done by Spearman's correlation. There was no association between lung surface and age or gender. There was no statistically significant association in lung surface between smokers and non-smokers 6.74 cm2 (3.47 to 10.02) versus 5.20cm2 (2.29 to 7.54), and there was no significant association between lung surface carbon and exposure to environmental PM and markers of traffic exposure. We did not find a statistically significant association between lung surface and smokers and non-smokers, and no statistically significant association between lung surface carbon and environmental exposure variables. These results suggest that lung surface carbon in long-term residents of São Paulo may predominately be from environmental PM, but the most appropriate environmental exposure marker remains unclear.
42 CFR 417.806 - Financial records, statistical data, and cost finding.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 42 Public Health 3 2011-10-01 2011-10-01 false Financial records, statistical data, and cost finding. 417.806 Section 417.806 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF..., statistical data, and cost finding. (a) The principles specified in § 417.568 apply to HCPPs, except those in...
42 CFR 417.806 - Financial records, statistical data, and cost finding.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 42 Public Health 3 2010-10-01 2010-10-01 false Financial records, statistical data, and cost finding. 417.806 Section 417.806 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF..., statistical data, and cost finding. (a) The principles specified in § 417.568 apply to HCPPs, except those in...
Prognostic significance of MRI findings in patients with myxoid-round cell liposarcoma.
Tateishi, Ukihide; Hasegawa, Tadashi; Beppu, Yasuo; Kawai, Akira; Satake, Mitsuo; Moriyama, Noriyuki
2004-03-01
The aims of this study were to determine the prognostic significance of MRI findings in patients with myxoid-round cell liposarcomas and to clarify which MRI features best indicate tumors with adverse clinical behavior. The initial MRI studies of 36 pathologically confirmed myxoid-round cell liposarcomas were retrospectively reviewed, and observations from this review were correlated with the histopathologic features. MR images were evaluated by two radiologists with agreement by consensus, and both univariate and multivariate analyses were conducted to evaluate survival with a median clinical follow-up of 33 months (range, 9-276 months). Statistically significant MRI findings that favored a diagnosis of intermediate- or high-grade tumor were large tumor size (> 10 cm), deeply situated tumor, tumor possessing irregular contours, absence of lobulation, absence of thin septa, presence of thick septa, absence of tumor capsule, high-intensity signal pattern, pronounced enhancement, and globular or nodular enhancement. Of these MRI findings, thin septa (p < 0.05), a tumor capsule (p < 0.01), and pronounced enhancement (p < 0.01) were associated significantly, according to univariate analysis, with overall survival. Multivariate analysis indicated that pronounced enhancement was associated significantly with overall survival (p < 0.05). Contrast-enhanced MRI findings can indicate a good or adverse prognosis in patients with myxoid-round cell liposarcomas.
NASA Astrophysics Data System (ADS)
Skorobogatiy, Maksim; Sadasivan, Jayesh; Guerboukha, Hichem
2018-05-01
In this paper, we first discuss the main types of noise in a typical pump-probe system, and then focus specifically on terahertz time domain spectroscopy (THz-TDS) setups. We then introduce four statistical models for the noisy pulses obtained in such systems, and detail rigorous mathematical algorithms to de-noise such traces, find the proper averages and characterise various types of experimental noise. Finally, we perform a comparative analysis of the performance, advantages and limitations of the algorithms by testing them on the experimental data collected using a particular THz-TDS system available in our laboratories. We conclude that using advanced statistical models for trace averaging results in the fitting errors that are significantly smaller than those obtained when only a simple statistical average is used.
Assessing the Probability that a Finding Is Genuine for Large-Scale Genetic Association Studies
Kuo, Chia-Ling; Vsevolozhskaya, Olga A.; Zaykin, Dmitri V.
2015-01-01
Genetic association studies routinely involve massive numbers of statistical tests accompanied by P-values. Whole genome sequencing technologies increased the potential number of tested variants to tens of millions. The more tests are performed, the smaller P-value is required to be deemed significant. However, a small P-value is not equivalent to small chances of a spurious finding and significance thresholds may fail to serve as efficient filters against false results. While the Bayesian approach can provide a direct assessment of the probability that a finding is spurious, its adoption in association studies has been slow, due in part to the ubiquity of P-values and the automated way they are, as a rule, produced by software packages. Attempts to design simple ways to convert an association P-value into the probability that a finding is spurious have been met with difficulties. The False Positive Report Probability (FPRP) method has gained increasing popularity. However, FPRP is not designed to estimate the probability for a particular finding, because it is defined for an entire region of hypothetical findings with P-values at least as small as the one observed for that finding. Here we propose a method that lets researchers extract probability that a finding is spurious directly from a P-value. Considering the counterpart of that probability, we term this method POFIG: the Probability that a Finding is Genuine. Our approach shares FPRP's simplicity, but gives a valid probability that a finding is spurious given a P-value. In addition to straightforward interpretation, POFIG has desirable statistical properties. The POFIG average across a set of tentative associations provides an estimated proportion of false discoveries in that set. POFIGs are easily combined across studies and are immune to multiple testing and selection bias. We illustrate an application of POFIG method via analysis of GWAS associations with Crohn's disease. PMID:25955023
Assessing the Probability that a Finding Is Genuine for Large-Scale Genetic Association Studies.
Kuo, Chia-Ling; Vsevolozhskaya, Olga A; Zaykin, Dmitri V
2015-01-01
Genetic association studies routinely involve massive numbers of statistical tests accompanied by P-values. Whole genome sequencing technologies increased the potential number of tested variants to tens of millions. The more tests are performed, the smaller P-value is required to be deemed significant. However, a small P-value is not equivalent to small chances of a spurious finding and significance thresholds may fail to serve as efficient filters against false results. While the Bayesian approach can provide a direct assessment of the probability that a finding is spurious, its adoption in association studies has been slow, due in part to the ubiquity of P-values and the automated way they are, as a rule, produced by software packages. Attempts to design simple ways to convert an association P-value into the probability that a finding is spurious have been met with difficulties. The False Positive Report Probability (FPRP) method has gained increasing popularity. However, FPRP is not designed to estimate the probability for a particular finding, because it is defined for an entire region of hypothetical findings with P-values at least as small as the one observed for that finding. Here we propose a method that lets researchers extract probability that a finding is spurious directly from a P-value. Considering the counterpart of that probability, we term this method POFIG: the Probability that a Finding is Genuine. Our approach shares FPRP's simplicity, but gives a valid probability that a finding is spurious given a P-value. In addition to straightforward interpretation, POFIG has desirable statistical properties. The POFIG average across a set of tentative associations provides an estimated proportion of false discoveries in that set. POFIGs are easily combined across studies and are immune to multiple testing and selection bias. We illustrate an application of POFIG method via analysis of GWAS associations with Crohn's disease.
On the observability of coupled dark energy with cosmic voids
NASA Astrophysics Data System (ADS)
Sutter, P. M.; Carlesi, Edoardo; Wandelt, Benjamin D.; Knebe, Alexander
2015-01-01
Taking N-body simulations with volumes and particle densities tuned to match the sloan digital sky survey DR7 spectroscopic main sample, we assess the ability of current void catalogues to distinguish a model of coupled dark matter-dark energy from Λ cold dark matter cosmology using properties of cosmic voids. Identifying voids with the VIDE toolkit, we find no statistically significant differences in the ellipticities, but find that coupling produces a population of significantly larger voids, possibly explaining the recent result of Tavasoli et al. In addition, we use the universal density profile of Hamaus et al. to quantify the relationship between coupling and density profile shape, finding that the coupling produces broader, shallower, undercompensated profiles for large voids by thinning the walls between adjacent medium-scale voids. We find that these differences are potentially measurable with existing void catalogues once effects from survey geometries and peculiar velocities are taken into account.
Evaluation of Three Different Processing Techniques in the Fabrication of Complete Dentures
Chintalacheruvu, Vamsi Krishna; Balraj, Rajasekaran Uttukuli; Putchala, Lavanya Sireesha; Pachalla, Sreelekha
2017-01-01
Aims and Objectives: The objective of the present study is to compare the effectiveness of three different processing techniques and to find out the accuracy of processing techniques through number of occlusal interferences and increase in vertical dimension after denture processing. Materials and Methods: A cross-sectional study was conducted on a sample of 18 patients indicated for complete denture fabrication was selected for the study and they were divided into three subgroups. Three processing techniques, compression molding and injection molding using prepolymerized resin and unpolymerized resin, were used to fabricate dentures for each of the groups. After processing, laboratory-remounted dentures were evaluated for number of occlusal interferences in centric and eccentric relations and change in vertical dimension through vertical pin rise in articulator. Data were analyzed using statistical test ANOVA and SPSS software version 19.0 by IBM was used. Results: Data obtained from three groups were subjected to one-way ANOVA test. After ANOVA test, results with significant variations were subjected to post hoc test. Number of occlusal interferences with compression molding technique was reported to be more in both centric and eccentric positions as compared to the two injection molding techniques with statistical significance in centric, protrusive, right lateral nonworking, and left lateral working positions (P < 0.05). Mean vertical pin rise (0.52 mm) was reported to more in compression molding technique as compared to injection molding techniques, which is statistically significant (P < 0.001). Conclusions: Within the limitations of this study, injection molding techniques exhibited less processing errors as compared to compression molding technique with statistical significance. There was no statistically significant difference in processing errors reported within two injection molding systems. PMID:28713763
Evaluation of Three Different Processing Techniques in the Fabrication of Complete Dentures.
Chintalacheruvu, Vamsi Krishna; Balraj, Rajasekaran Uttukuli; Putchala, Lavanya Sireesha; Pachalla, Sreelekha
2017-06-01
The objective of the present study is to compare the effectiveness of three different processing techniques and to find out the accuracy of processing techniques through number of occlusal interferences and increase in vertical dimension after denture processing. A cross-sectional study was conducted on a sample of 18 patients indicated for complete denture fabrication was selected for the study and they were divided into three subgroups. Three processing techniques, compression molding and injection molding using prepolymerized resin and unpolymerized resin, were used to fabricate dentures for each of the groups. After processing, laboratory-remounted dentures were evaluated for number of occlusal interferences in centric and eccentric relations and change in vertical dimension through vertical pin rise in articulator. Data were analyzed using statistical test ANOVA and SPSS software version 19.0 by IBM was used. Data obtained from three groups were subjected to one-way ANOVA test. After ANOVA test, results with significant variations were subjected to post hoc test. Number of occlusal interferences with compression molding technique was reported to be more in both centric and eccentric positions as compared to the two injection molding techniques with statistical significance in centric, protrusive, right lateral nonworking, and left lateral working positions ( P < 0.05). Mean vertical pin rise (0.52 mm) was reported to more in compression molding technique as compared to injection molding techniques, which is statistically significant ( P < 0.001). Within the limitations of this study, injection molding techniques exhibited less processing errors as compared to compression molding technique with statistical significance. There was no statistically significant difference in processing errors reported within two injection molding systems.
Mohammad, Ghulam; Allegaert, Eef; Ahmad, Ajmal; Siddiquei, Mohammad Mairaj; Alam, Kaiser; Gikandi, Priscilla W.; De Hertogh, Gert; Opdenakker, Ghislain
2018-01-01
Purpose Matrix metalloproteinase-14 (MMP-14) is a transmembrane MMP that plays a critical role in promoting angiogenesis. We investigated the expression levels of MMP-14 and correlated the levels with clinical disease activity and with the levels of the angiogenic factors vascular endothelial growth factor (VEGF) and MMP-9 in proliferative diabetic retinopathy (PDR). To reinforce the findings at the functional level, we examined the expression of MMP-14 in the retinas of diabetic rats. Methods Vitreous samples from 34 patients with PDR and 18 nondiabetic patients and epiretinal membranes from 13 patients with PDR and the retinas of rats were studied with enzyme-linked immunosorbent assay, immunohistochemistry, western blotting, and real-time reverse transcription PCR (RT–PCR). Results The MMP-14, VEGF, and MMP-9 levels were statistically significantly higher in the vitreous samples from patients with PDR than in the samples from the nondiabetic controls (p<0.001 for all comparisons). The MMP-14 levels in patients with PDR with active neovascularization were statistically significantly higher than those in patients with inactive PDR (p<0.001). There were statistically significant positive correlations between levels of MMP-14 and levels of VEGF (r = 0.3; p = 0.032) and MMP-9 (r = 0.54; p<0.001). In the epiretinal membranes, MMP-14 was expressed in vascular endothelial cells, leukocytes, and myofibroblasts. Statistically significant positive correlations were detected between the numbers of blood vessels expressing CD31 and the numbers of blood vessels (r = 0.74; p = 0.004) and stromal cells (r = 0.72; p = 0.005) expressing MMP-14. Statistically significant increases of MMP-14 mRNA and protein were detected in rat retinas after induction of diabetes. Conclusions These results suggest that MMP-14 is involved in PDR angiogenesis. PMID:29853773
Ishii, Namiko; Sakuma, Ayaka; Makino, Yohsuke; Torimitsu, Suguru; Yajima, Daisuke; Inokuchi, Go; Motomura, Ayumi; Chiba, Fumiko; Hoshioka, Yumi; Iwase, Hirotaro; Saitoh, Hisako
2016-09-01
The purpose of this study was to determine the incidence of three-rooted mandibular first molars in a contemporary Japanese population using multidetector computed tomography (MDCT) and examine whether this characteristic root form may be useful for identification purposes. Prior to their forensic autopsies, we obtained MDCT scans of 365 cadavers (255 males, 110 females) with mandibular first molars on both sides. Altogether, 730 mandibular first molars were examined morphologically on reconstructed CT images, and the incidence of three-rooted molars was recorded. The results were analyzed statistically to determine sex and left-right differences using the chi-square test. In all, 189 (25.9%) of the 730 mandibular first molars had three roots: 79 (31.0%) in the 255 males and 35 (31.8%) in the 110 females. No statistically significant difference was found between the sexes. In the 39 individuals who had unilateral three-rooted mandibular first molars, 7 (17.9%) were on the left side and 32 (82.1%) were on the right side, indicating a statistically significant predominance on the right side. The incidence of three-rooted mandibular first molars in contemporary Japanese individuals was 25.9%, with no statistically significant sex difference, but in the case of unilateral three-rooted teeth, with a statistically significant predominance on the right side. Our study found that Japanese and northeastern Asians have a high incidence of the three-rooted mandibular first molars among individuals of Mongolian origin; this finding may be a useful screening tool for identification of unknown individuals. Copyright © 2016. Published by Elsevier Ireland Ltd.
An Analysis of Selectivity Bias in the Medicare AAPCC
Dowd, Bryan; Feldman, Roger; Moscovice, Ira; Wisner, Catherine; Bland, Pat; Finch, Mike
1996-01-01
Using econometric models of endogenous sample selection, we examine possible payment bias to Medicare Tax Equity and Fiscal Responsibility Act of 1982 (TEFRA)-risk health maintenance organizations (HMOs) in the Twin Cities in 1988. We do not find statistically significant evidence of favorable HMO selection. In fact, the sign of the selection term indicates adverse selection into HMOs. This finding is interesting, in view of the fact that three of the five risk HMOs in the study have since converted to non-risk contracts. PMID:10158735
Nontraditional families and childhood progress through school: a comment on Rosenfeld.
Allen, Douglas W; Pakaluk, Catherine; Price, Joseph
2013-06-01
We reexamine Rosenfeld's (2010) study on the association between child outcomes and same-sex family structure. Using the same data set, we replicate and generalize Rosenfeld's findings and show that the implications of his study are different when using either alternative comparison groups or alternative sample restrictions. Compared with traditional married households, we find that children being raised by same-sex couples are 35 % less likely to make normal progress through school; this difference is statistically significant at the 1 % level.
When chefs adopt a school? An evaluation of a cooking intervention in English primary schools.
Caraher, Martin; Seeley, Annie; Wu, Michelle; Lloyd, Susan
2013-03-01
This article sets out the findings from research on the impact of a, UK based, chefs in schools teaching programme on food, health, nutrition and cookery. Professional chefs link with local schools, where they deliver up to three sessions to one class over a year. The research measured the impact of a standardised intervention package and changes in food preparation and consumption as well as measuring cooking confidence. The target group was 9-11year olds in four schools. The main data collection method was a questionnaire delivered 2weeks before the intervention and 2weeks afterwards. There was a group of four matched control schools. Those taking part in the intervention were enthused and engaged by the sessions and the impact measures indicated an intention to change. There were gains in skills and confidence to prepare and ask for the ingredients to be purchased for use in the home. Following the session with the chef, the average reported cooking confidence score increased from 3.09 to 3.35 (by 0.26 points) in the intervention group - a statistically significant improvement. In the control group this change was not statistically significant. Children's average reported vegetable consumption increased after the session with the chef, with the consumption score increasing from 2.24 to 2.46 points (0.22 points) again, a statistically significant increase with no significant changes in the control group. The research highlights the need to incorporate evaluation into school cooking initiatives as the findings can provide valuable information necessary to fine-tune interventions and to ensure consistency of the healthy eating messages. Copyright © 2012 Elsevier Ltd. All rights reserved.
Comparison of superior septal approach with left atriotomy in mitral valve surgery
Aydin, Ebuzer; Arslan, Akin; Ozkokeli, Mehmet
2014-01-01
Objective In this study, we aimed to compare clinical outcomes of superior transseptal approach with the conventional left atriotomy in patients undergoing mitral valve surgery. Methods Between January 2010 and November 2012, a total of 91 consecutive adult patients (39 males, 52 females; mean age: 54.0±15.4 years; range, 16 to 82 years) who underwent mitral valve surgery in the Division of Cardiovascular Surgery at Koşuyolu Training Hospital were included. The patients were randomized to either superior transseptal approach (n=47) or conventional left atriotomy (n=44). Demographic characteristics of the patients, comorbidities, additional interventions, intraoperational data, pre- and postoperative electrophysiological study findings, and postoperative complications were recorded. Results Of all patients, 86.7% (n=79) were in New York Heart Association Class III, while 12 were in New York Heart Association Class IV. All patients underwent annuloplasty (42.9%) or valve replacement surgery (57.1%). There was no significant difference in pre- and postoperative electrocardiogram findings between the groups. Change from baseline in the cardiac rhythm was statistically significant in superior transseptal approach group alone (P<0.001). There was no statistically significant difference in mortality rate between the groups. Permanent pacemaker implantation was performed in 10.6% of the patients in superior transseptal approach group and 4.5% in the conventional left atriotomy group. No statistically significant difference in bleeding, total length of hospital and intensive care unit stay, the presence of low cardiac output syndrome was observed between the groups. Conclusion Our study results suggest that superior transseptal approach does not lead to serious or fatal adverse effects on sinus node function or atrial vulnerability, compared to conventional approach. PMID:25372911
Sone, Daichi; Sato, Noriko; Kimura, Yukio; Watanabe, Yutaka; Okazaki, Mitsutoshi; Matsuda, Hiroshi
2018-06-01
Although epilepsy in the elderly has attracted attention recently, there are few systematic studies of neuroimaging in such patients. In this study, we used structural MRI and diffusion tensor imaging (DTI) to investigate the morphological and microstructural features of the brain in late-onset temporal lobe epilepsy (TLE). We recruited patients with TLE and an age of onset > 50 years (late-TLE group) and age- and sex-matched healthy volunteers (control group). 3-Tesla MRI scans, including 3D T1-weighted images and 15-direction DTI, showed normal findings on visual assessment in both groups. We used Statistical Parametric Mapping 12 (SPM12) for gray and white matter structural normalization and comparison and used Tract-Based Spatial Statistics (TBSS) for fractional anisotropy and mean diffusivity comparisons of DTI. In both methods, p < 0.05 (family-wise error) was considered statistically significant. In total, 30 patients with late-onset TLE (mean ± SD age, 66.8 ± 8.4; mean ± SD age of onset, 63.0 ± 7.6 years) and 40 healthy controls (mean ± SD age, 66.6 ± 8.5 years) were enrolled. The late-onset TLE group showed significant gray matter volume increases in the bilateral amygdala and anterior hippocampus and significantly reduced mean diffusivity in the left temporofrontal lobe, internal capsule, and brainstem. No significant changes were evident in white matter volume or fractional anisotropy. Our findings may reflect some characteristics or mechanisms of cryptogenic TLE in the elderly, such as inflammatory processes.
Catron, Tom D; Smallfield, George B; Kang, Le; Sterling, Richard K; Siddiqui, Mohammad S
2017-11-01
Gastric varices (GV) have higher rates of morbidity and mortality from hemorrhage than esophageal varices. Several studies have shown the safety and efficacy of cyanoacrylate (CA) injection for acute gastric variceal hemorrhage. We report data from our experience with CA injection for GV before and after routine use of post-injection audible Doppler assessment (ADA) for GV obturation and describe long-term outcomes after this therapy. We retrospectively identified patients who had documented GV, underwent CA injection, and had at least 2 weeks of follow-up. We recorded and analyzed the survival and rebleeding rates with patient demographics, clinical data, and endoscopy findings between two groups of patients who were categorized by CA injection prior to and after inception of the ADA technique. Seventy-one patients were identified with 16 patients analyzed in a group where ADA was not used (Pre-ADA) and 55 analyzed where ADA was used (Post-ADA). No rebleeding events were observed within 1 week of initial CA injection. No embolic events were reported after any initial CA injection within 4 weeks. The rate of bleed-free survival at 1 year was 69.6% in the Pre-ADA group and 85.8% in the Post-ADA without statistical significance. The all-cause 1-year mortality was 13.8% in the Pre-ADA group and 10.7% in the Post-ADA group without statistical significance. ADA of CA-injected GV does not appear to significantly affect adverse events or clinical outcomes; however, our findings are limited by small sample size and cohort proportions allowing for significant type II statistical error. Further prospective investigation is required to determine the impact of ADA on clinical outcomes after GV obturation.
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.
[The mitral valve prolapse syndrome in children and adolescents].
Malcić, I; Zavrsnik, J; Kancler, K; Kokol, P
1998-01-01
The authors studied the prevalence of mitral valve prolapse (MVP) in the group of 656 children and adolescents (329 males and 327 females), who were a representative sample (obtained with the Monte Carlo method of statistical trials) of all newborns in the city of Maribor, Republic of Slovenia, in the period of 18 years (1976-1992). The results were considered positive in children and adolescents who in addition to possible history (chest pain, palpitations, dizziness, loss of consciousness, headaches, perspiration), probable auscultatory finding (mezzosystolic click and late systolic murmur), and suspected phonocardiographic and ECG findings, also had a positive M-mode echocardiographic finding. The criteria for MVP on M-mode echocardiography were taken from the literature: descending of mitral cusp, either anterior or posterior, of at least 3 mm below the line connecting points C and D. Children and adolescents were divided into six age groups (infants, toddlers, preschool children, early school age, children in puberty, adolescents). Assuming MVP as a cause of cardiac arrhythmias, beside standard ECG we also performed holter ECG monitoring in 61 children and adolescents (29 with MVP, 32 without MVP). The results were tested with standard statistical tools (chi 2-test, Student t-test, 2 x 2 Fisher chi 2-test). MVP was found in 71 patients (10.8%, 32 males and 39 females). As regards age and sex we found lower prevalence of MVP in male children (9.7%) compared to female children (11.9%). The highest prevalence was found in early school age, more so in females (14.2 vs 13.7). The differences were not statistically significant (p > 0.05). In both sexes most frequent was endosystolic prolapse (males 59.3%, females 51.3%). Most commonly both cusps are involved in the prolapse (males 78.1%, females 66.7%). Most frequently measured descending of the cusps was 3-4.5 mm (males 56.2%, females 48.7%). Negative auscultatory finding (silent MVP) was detected in 47.8% of the patients with MVP. Most patients with diagnosed MVP had no symptoms (71.8%). The prevalence of asymptomatic MVP declines with age in both sexes. The prevalence of arrhythmias, both in standard ECG and holter ECG, is higher in patients with MVP (6.8:0%--NS and 44.6%:9.3%--p < 0.05). The influence of constitutional changes (dolichostenomelia, asthenic constitution, genua valga) on the appearance of MVP is reflected in statistically significant difference in the Rohr' index in the group of patients with MVP in relation to the healthy group (p < 0.05). The higher prevalence of headache and dizziness in the group with MVP is statistically significant (p < 0.05).
Statistical analysis of 4 types of neck whiplash injuries based on classical meridian theory.
Chen, Yemeng; Zhao, Yan; Xue, Xiaolin; Li, Hui; Wu, Xiuyan; Zhang, Qunce; Zheng, Xin; Wang, Tianfang
2015-01-01
As one component of the Chinese medicine meridian system, the meridian sinew (Jingjin, (see text), tendino-musculo) is specially described as being for acupuncture treatment of the musculoskeletal system because of its dynamic attributes and tender point correlations. In recent decades, the therapeutic importance of the sinew meridian has become revalued in clinical application. Based on this theory, the authors have established therapeutic strategies of acupuncture treatment in Whiplash-Associated Disorders (WAD) by categorizing four types of neck symptom presentations. The advantage of this new system is to make it much easier for the clinician to find effective acupuncture points. This study attempts to prove the significance of the proposed therapeutic strategies by analyzing data collected from a clinical survey of various WAD using non-supervised statistical methods, such as correlation analysis, factor analysis, and cluster analysis. The clinical survey data have successfully verified discrete characteristics of four neck syndromes, based upon the range of motion (ROM) and tender point location findings. A summary of the relationships among the symptoms of the four neck syndromes has shown the correlation coefficient as having a statistical significance (P < 0.01 or P < 0.05), especially with regard to ROM. Furthermore, factor and cluster analyses resulted in a total of 11 categories of general symptoms, which implies syndrome factors are more related to the Liver, as originally described in classical theory. The hypothesis of meridian sinew syndromes in WAD is clearly supported by the statistical analysis of the clinical trials. This new discovery should be beneficial in improving therapeutic outcomes.
Neurological Outcomes Following Suicidal Hanging: A Prospective Study of 101 Patients
Jawaid, Mohammed Turab; Amalnath, S. Deepak; Subrahmanyam, D. K. S.
2017-01-01
Context: Survivors of suicidal hanging can have variable neurological outcomes – from complete recovery to irreversible brain damage. Literature on the neurological outcomes in these patients is confined to retrospective studies and case series. Hence, this prospective study was carried out. Aims: The aim is to study the neurological outcomes in suicidal hanging. Settings and Design: This was a prospective observational study carried out from July 2014 to July 2016. Subjects and Methods: Consecutive patients admitted to the emergency and medicine wards were included in the study. Details of the clinical and radiological findings, course in hospital and at 1 month postdischarge were analyzed. Statistical Analysis Used: Statistical analysis was performed using IBM SPSS advanced statistics 20.0 (SPSS Inc., Chicago, USA). Univariate analysis was performed using Chi-square test for significance and Odd's ratio was calculated. Results: Of the 101 patients, 6 died and 4 had residual neuro deficits. Cervical spine injury was seen in 3 patients. Interestingly, 39 patients could not remember the act of hanging (retrograde amnesia). Hypotension, pulmonary edema, Glasgow coma scale (GCS) score <8 at admission, need for mechanical ventilation, and cerebral edema on plain computed tomography were more in those with amnesia as compared to those with normal memory and these findings were statistically significant. Conclusions: Majority of patients recovered without any sequelae. Routine imaging of cervical spine may not be warranted in all patients, even in those with poor GCS. Retrograde amnesia might be more common than previously believed and further studies are needed to analyze this peculiar feature. PMID:28584409
Accounting for measurement error: a critical but often overlooked process.
Harris, Edward F; Smith, Richard N
2009-12-01
Due to instrument imprecision and human inconsistencies, measurements are not free of error. Technical error of measurement (TEM) is the variability encountered between dimensions when the same specimens are measured at multiple sessions. A goal of a data collection regimen is to minimise TEM. The few studies that actually quantify TEM, regardless of discipline, report that it is substantial and can affect results and inferences. This paper reviews some statistical approaches for identifying and controlling TEM. Statistically, TEM is part of the residual ('unexplained') variance in a statistical test, so accounting for TEM, which requires repeated measurements, enhances the chances of finding a statistically significant difference if one exists. The aim of this paper was to review and discuss common statistical designs relating to types of error and statistical approaches to error accountability. This paper addresses issues of landmark location, validity, technical and systematic error, analysis of variance, scaled measures and correlation coefficients in order to guide the reader towards correct identification of true experimental differences. Researchers commonly infer characteristics about populations from comparatively restricted study samples. Most inferences are statistical and, aside from concerns about adequate accounting for known sources of variation with the research design, an important source of variability is measurement error. Variability in locating landmarks that define variables is obvious in odontometrics, cephalometrics and anthropometry, but the same concerns about measurement accuracy and precision extend to all disciplines. With increasing accessibility to computer-assisted methods of data collection, the ease of incorporating repeated measures into statistical designs has improved. Accounting for this technical source of variation increases the chance of finding biologically true differences when they exist.
Close, Helen; Mason, James M; Wilson, Douglas; Hungin, A Pali S
2012-05-29
Oestrogen and progestogen have the potential to influence gastro-intestinal motility; both are key components of hormone replacement therapy (HRT). Results of observational studies in women taking HRT rely on self-reporting of gastro-oesophageal symptoms and the aetiology of gastro-oesophageal reflux disease (GORD) remains unclear. This study investigated the association between HRT and GORD in menopausal women using validated general practice records. 51,182 menopausal women were identified using the UK General Practice Research Database between 1995-2004. Of these, 8,831 were matched with and without hormone use. Odds ratios (ORs) were calculated for GORD and proton-pump inhibitor (PPI) use in hormone and non-hormone users, adjusting for age, co-morbidities, and co-pharmacy. In unadjusted analysis, all forms of hormone use (oestrogen-only, tibolone, combined HRT and progestogen) were statistically significantly associated with GORD. In adjusted models, this association remained statistically significant for oestrogen-only treatment (OR 1.49; 1.18-1.89). Unadjusted analysis showed a statistically significant association between PPI use and oestrogen-only and combined HRT treatment. When adjusted for covariates, oestrogen-only treatment was significant (OR 1.34; 95% CI 1.03-1.74). Findings from the adjusted model demonstrated the greater use of PPI by progestogen users (OR 1.50; 1.01-2.22). This first large cohort study of the association between GORD and HRT found a statistically significant association between oestrogen-only hormone and GORD and PPI use. This should be further investigated using prospective follow-up to validate the strength of association and describe its clinical significance.
Statistical regularities of art images and natural scenes: spectra, sparseness and nonlinearities.
Graham, Daniel J; Field, David J
2007-01-01
Paintings are the product of a process that begins with ordinary vision in the natural world and ends with manipulation of pigments on canvas. Because artists must produce images that can be seen by a visual system that is thought to take advantage of statistical regularities in natural scenes, artists are likely to replicate many of these regularities in their painted art. We have tested this notion by computing basic statistical properties and modeled cell response properties for a large set of digitized paintings and natural scenes. We find that both representational and non-representational (abstract) paintings from our sample (124 images) show basic similarities to a sample of natural scenes in terms of their spatial frequency amplitude spectra, but the paintings and natural scenes show significantly different mean amplitude spectrum slopes. We also find that the intensity distributions of paintings show a lower skewness and sparseness than natural scenes. We account for this by considering the range of luminances found in the environment compared to the range available in the medium of paint. A painting's range is limited by the reflective properties of its materials. We argue that artists do not simply scale the intensity range down but use a compressive nonlinearity. In our studies, modeled retinal and cortical filter responses to the images were less sparse for the paintings than for the natural scenes. But when a compressive nonlinearity was applied to the images, both the paintings' sparseness and the modeled responses to the paintings showed the same or greater sparseness compared to the natural scenes. This suggests that artists achieve some degree of nonlinear compression in their paintings. Because paintings have captivated humans for millennia, finding basic statistical regularities in paintings' spatial structure could grant insights into the range of spatial patterns that humans find compelling.
Cao, Hui; Markatou, Marianthi; Melton, Genevieve B; Chiang, Michael F; Hripcsak, George
2005-01-01
This paper applies co-occurrence statistics to discover disease-finding associations in a clinical data warehouse. We used two methods, chi2 statistics and the proportion confidence interval (PCI) method, to measure the dependence of pairs of diseases and findings, and then used heuristic cutoff values for association selection. An intrinsic evaluation showed that 94 percent of disease-finding associations obtained by chi2 statistics and 76.8 percent obtained by the PCI method were true associations. The selected associations were used to construct knowledge bases of disease-finding relations (KB-chi2, KB-PCI). An extrinsic evaluation showed that both KB-chi2 and KB-PCI could assist in eliminating clinically non-informative and redundant findings from problem lists generated by our automated problem list summarization system.
2017-09-01
NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS DATABASE CREATION AND STATISTICAL ANALYSIS: FINDING CONNECTIONS BETWEEN TWO OR MORE SECONDARY...BLANK ii Approved for public release. Distribution is unlimited. DATABASE CREATION AND STATISTICAL ANALYSIS: FINDING CONNECTIONS BETWEEN TWO OR MORE...Problem and Motivation . . . . . . . . . . . . . . . . . . . 1 1.2 DOD Applicability . . . . . . . . . . . . . . . . .. . . . . . . 2 1.3 Research
The Achievement Impacts of Arkansas Open-Enrollment Charter Schools
ERIC Educational Resources Information Center
Mills, Jonathan N.
2013-01-01
This article examines the impacts of Arkansas charter schools on the academic achievement of participating students. Our findings are that charter schools have small but statistically significant, negative impacts on student achievements for both math and literacy. Such negative effects, however, tend to decline with the number of years of charter…
ERIC Educational Resources Information Center
Kiliçkaya, Ferit
2015-01-01
This study aims to find out whether there are any statistically significant differences in participants' achievements on three different types of instruction: computer-based instruction, teacher-driven instruction, and teacher-driven grammar supported by computer-based instruction. Each type of instruction follows the deductive approach. The…
Influences on Labor Market Outcomes of African American College Graduates: A National Study
ERIC Educational Resources Information Center
Strayhorn, Terrell L.
2008-01-01
Using an expanded econometric model, this study sought to estimate more precisely the net effect of independent variables (i.e., attending an HBCU) on three measures of labor market outcomes for African American college graduates. Findings reveal a statistically significant, albeit moderate, relationship between measures of background, human and…
ERIC Educational Resources Information Center
Shi, Qi; Steen, Sam
2010-01-01
A group counseling intervention with beginning-level ESL students in middle school is presented. Findings from the pre- and post-group evaluations showed statistically significant improvement in students' reading and writing skills and appropriate classroom behaviors. Limitations of the research design are discussed and implications for school…
ERIC Educational Resources Information Center
Gerdes, Alyson C.; Haack, Lauren M.; Schneider, Brian W.
2012-01-01
Objective/Method: Statistically significant and clinically meaningful effects of behavioral parent training on parental functioning were examined for 20 children with ADHD and their parents who had successfully completed a psychosocial treatment for ADHD. Results/Conclusion: Findings suggest that behavioral parent training resulted in…
ERIC Educational Resources Information Center
Gunersel, Adalet Baris; Fleming, Steven
2014-01-01
Research shows that computer animations are especially helpful in fields such as chemistry and in this mixed-methods study, we investigate the educational effectiveness of Bio-Organic Reaction Animations (BioORA), a 3-D software, in four undergraduate biochemistry classes at different universities. Statistically significant findings indicate that…
ERIC Educational Resources Information Center
Thompson, Bruce
1999-01-01
A study examined effect-size reporting in 23 quantitative articles reported in "Exceptional Children". Findings reveal that effect sizes are rarely being reported, although exemplary reporting practices were also noted. Reasons why encouragement by the American Psychological Association to report effect size has been ineffective are…
Physical Activity and Perceived Self-Efficacy in Older Adults.
ERIC Educational Resources Information Center
Langan, Mary E.; Marotta, Sylvia A.
2000-01-01
The purpose of this study was to examine predictors of self-efficacy in older adults, with physical activity, age, and sex as the predictor variables. Regression analyses revealed physical activity to be the only statistically significant predictor of self-efficacy. These findings may be of interest to counselors who work with older people.…
Bagstad, Kenneth J.; Semmens, Darius J.; Ancona, Zachary H.; Sherrouse, Ben C.
2017-01-01
Statistical hotspot methods of intermediate conservatism (i.e., Getis-Ord Gi*, α = 0.10 significance) may be most useful for ecosystem service hot/coldspot mapping to inform landscape scale planning. We also found spatially explicit evidence in support of past findings about public attitudes toward wilderness areas.
Self-efficacy: a mediator of smoking behavior and depression among college students.
Mee, Susan
2014-01-01
Cigarette smoking is a growing problem among adolescents. This correlational study tested theoretical relationships between the dependent variable (smoking behavior) and the independent variables (depression and smoking resistance self-efficacy) in a convenience sample of 364 college students ages 18 to 21 years recruited from a large urban public college. An a priori mediational model tested the role of smoking resistance self-efficacy as a mediator in the relationship between smoking behavior and depression. Findings showed there was a statistically significant positive relationship between depression and smoking behavior (r = 0.122, p = 0.01). There was a statistically significant negative relationship between smoking resistance self-efficacy and smoking behavior (r = -0.744, p = 0.01). Additionally, smoking resistance self-efficacy was a mediator of the relationship between depression and smoking behavior (beta = -0.757, p = 0.001). This study identifies a need for further theory-driven study of the relation of adolescent depression and smoking behavior. The findings of this study have implications for nursing interventions targeted to both current smokers and smoking initiation prevention programs.
Ayahuasca in adolescence: a neuropsychological assessment.
Doering-Silveira, Evelyn; Lopez, Enrique; Grob, Charles S; de Rios, Marlene Dobkin; Alonso, Luisa K; Tacla, Cristiane; Shirakawa, Itiro; Bertolucci, Paulo H; Da Silveira, Dartiu X
2005-06-01
The purpose of the study was to evaluate neuropsychologically adolescents who use ayahuasca in a religious context. A battery of neuropsychological tests was administered to adolescents who use ayahuasca. These subjects were compared to a matched control group of adolescents who did not use ayahuasca. The controls were matched with regards to sex, age, and education. The neuropsychological battery included tests of speeded attention, visual search, sequencing, psychomotor speed, verbal and visual abilities, memory, and mental flexibility. The statistical results for subjects from matched controls on neuropsychological measures were computed using independent t-tests. Overall, statistical findings suggested that there was no significant difference between the two groups on neuropsychological measures. Even though, the data overall supports that there was not a difference between ayahuasca users and matched controls on neuropsychological measures, further studies are necessary to support these findings.
Hospital graduate social work field work programs: a study in New York City.
Showers, N
1990-02-01
Twenty-seven hospital field work programs in New York City were studied. Questionnaires were administered to program coordinators and 238 graduate social work students participating in study programs. High degrees of program structural complexity and variation were found, indicating a state of art well beyond that described in the general field work literature. High rates of student satisfaction with learning, field instructors, programs, and the overall field work experience found suggest that the complexity of study programs may be more effective than traditional field work models. Statistically nonsignificant study findings indicate areas in which hospital social work departments may develop field work programs consistent with shifting organizational needs, without undue risk to educational effectiveness. Statistically significant findings suggest areas in which inflexibility in program design may be more beneficial in the diagnostic related groups era.
Kara-Junior, Newton; Espindola, Rodrigo F; Gomes, Beatriz A F; Ventura, Bruna; Smadja, David; Santhiago, Marcony R
2011-12-01
To evaluate the possible side effects and potential protection 5 years after implantation of an intraocular lens (IOL) with a blue-light filter (yellow tinted). Ophthalmology Department, University of São Paulo, São Paulo, Brazil. Prospective randomized clinical study. Patients with bilateral visually significant cataract randomly received an ultraviolet (UV) and blue light-filtering IOL (Acrysof Natural SN60AT) in 1 eye and an acrylic UV light-filtering only IOL (Acrysof SA60AT) in the fellow eye. The primary outcome measures were contrast sensitivity, color vision, and macular findings 5 years after surgery. The study enrolled 60 eyes of 30 patients. There were no significant clinical or optical coherence tomography findings in terms of age-related macular degeneration in any eye. There were no statistically significant differences in central macular thickness between the 2 IOL groups (P=.712). There were also no significant between-group differences under photopic or scotopic conditions at any spatial frequency studied. No statistically significant differences in the color discrimination test were found between the 2 IOL groups (P=.674). After 5 years, there were no significant differences in color perception, scotopic contrast sensitivity, or photopic contrast sensitivity between the blue light-filtering (yellow-tinted) IOL and the IOL with a UV-light filter only (untinted). The potential advantage of the tinted IOL in providing protection to macular cells remains unclear. Copyright © 2011 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.
A five year review of paediatric burns and social deprivation: Is there a link?
Richards, Helen; Kokocinska, Maria; Lewis, Darren
2017-09-01
To establish if there is a correlation between burn incidence and social deprivation in order to formulate a more effective burns prevention strategy. A quantitative retrospective review of International Burn Injury Database (IBID) was carried out over a period from 2006 to 2011 to obtain data for children referred to our burns centre in West Midlands. Social deprivation scores for geographical areas were obtained from Office of National Statistics (ONS). Statistical analysis was carried out using Graphpad Prism. 1688 children were reviewed at our burns centre. Statistical analysis using Pearson correlation coefficient showed a slight association between social deprivation and increasing burn incidence r 2 =0.1268, 95% confidence interval 0.018-0.219, p value<0.0001. There was a slight male preponderance (58%). The most common mechanism of injury was scalding (61%). The most commonly affected age group were 1-2 year olds (38%). There were statistically significant differences in the ethnicity of children with significantly more children from Asian and African backgrounds being referred compared to Caucasian children. We found that appropriate first aid was administered in 67% of cases overall. We did not find a statistically significant link between first aid provision and social deprivation score. There was only a slight positive correlation between social deprivation and burn incidence. However, there did not seem to be any change in mechanism of burn in the most deprived groups compared to overall pattern, nor was there a significant difference in appropriate first aid provision. It would seem that dissemination of burn prevention strategies and first aid advice need to be improved across all geographical areas as this was uniformly lacking and the increased burn incidence in more socially deprived groups, although present, was not statistically significant. Copyright © 2017 Elsevier Ltd and ISBI. All rights reserved.
Sustainable energy policy: the impact of government subsidies on ethanol as a renewable fuel
NASA Astrophysics Data System (ADS)
Osuagwu, Denis Ahamarula
The United States Congress passed the Energy Policy Act of 1978 to promote ethanol production and reduce American dependence on foreign oil. The provision of subsidies in the act is indicative of the importance of energy in the economy. America needs a national energy policy that is economically, socially, and environmentally sustainable. Considering the importance of these needs, this study examines (a) the implementation of the Energy Policy Act of 1978 in regard to government subsidies and its effect on ethanol production, (b) the effect of gasoline consumption and cost on ethanol production, (c) the effect of corn production and price on ethanol fuel, and (d) the role of mandates and global crises on ethanol production. Secondary qualitative and quantitative data collected from various sources in 1978 through 2005 study the effect of ethanol subsidies on ethanol production. An autoregression error model is used to estimate the relevance of the explanatory variables on variations in ethanol production. The following are major study findings: (1) there is a positive correlation between corn production and ethanol production, is statistically significant; (2) government subsidies have a statistically significant positive correlation with ethanol production; (3) oil import has a statistically significant positive correlation with ethanol production, but has not contributed to a reduction the quantity of imported oil; (4) the price of corn has a statistically significant inverse relationship with ethanol production; (5) though not statistically significant, the price per barrel of oil is inversely related to ethanol production; (6) the budget surplus or deficit is associated with ethanol production; and (7) advocacy and lobbying for renewable fuel have encouraged support of ethanol production. The findings also show that global crises in the oil producing regions tend to influence the passage of favorable legislation for ethanol production. Furthermore, the incremental approach to implementation of alternative energy programs has been a failure. In the absence of a national energy regulation policy, oil import is on the increase; exacerbating American dependence on foreign supplies. A sustainable energy policy requires vision and commitment, but policymakers do not seem to command political capital to achieve this objective. Investigation reveals that subsidies have contributed in the production of ethanol. The four billion gallons of ethanol produced in 2005 is significantly higher than the quantity produced in 1978. However, an increase in ethanol production has made no considerable contribution to reducing American dependence on foreign oil. A sustainable energy policy requires a proactive public policy that includes public and private investment in renewable energy and technology, together with a continuance of local oil drilling.
NASA Astrophysics Data System (ADS)
Sellentin, Elena; Heavens, Alan F.
2018-01-01
We investigate whether a Gaussian likelihood, as routinely assumed in the analysis of cosmological data, is supported by simulated survey data. We define test statistics, based on a novel method that first destroys Gaussian correlations in a data set, and then measures the non-Gaussian correlations that remain. This procedure flags pairs of data points that depend on each other in a non-Gaussian fashion, and thereby identifies where the assumption of a Gaussian likelihood breaks down. Using this diagnosis, we find that non-Gaussian correlations in the CFHTLenS cosmic shear correlation functions are significant. With a simple exclusion of the most contaminated data points, the posterior for s8 is shifted without broadening, but we find no significant reduction in the tension with s8 derived from Planck cosmic microwave background data. However, we also show that the one-point distributions of the correlation statistics are noticeably skewed, such that sound weak-lensing data sets are intrinsically likely to lead to a systematically low lensing amplitude being inferred. The detected non-Gaussianities get larger with increasing angular scale such that for future wide-angle surveys such as Euclid or LSST, with their very small statistical errors, the large-scale modes are expected to be increasingly affected. The shifts in posteriors may then not be negligible and we recommend that these diagnostic tests be run as part of future analyses.
Search for the sidereal and solar diurnal modulations in the total MACRO muon data set
NASA Astrophysics Data System (ADS)
Ambrosio, M.; Antolini, R.; Baldini, A.; Barbarino, G. C.; Barish, B. C.; Battistoni, G.; Becherini, Y.; Bellotti, R.; Bemporad, C.; Bernardini, P.; Bilokon, H.; Bower, C.; Brigida, M.; Bussino, S.; Cafagna, F.; Calicchio, M.; Campana, D.; Carboni, M.; Caruso, R.; Cecchini, S.; Cei, F.; Chiarella, V.; Chiarusi, T.; Choudhary, B. C.; Coutu, S.; Cozzi, M.; de Cataldo, G.; Dekhissi, H.; de Marzo, C.; de Mitri, I.; Derkaoui, J.; de Vincenzi, M.; di Credico, A.; Erriquez, O.; Favuzzi, C.; Forti, C.; Fusco, P.; Giacomelli, G.; Giannini, G.; Giglietto, N.; Giorgini, M.; Grassi, M.; Grillo, A.; Gustavino, C.; Habig, A.; Hanson, K.; Heinz, R.; Katsavounidis, E.; Katsavounidis, I.; Kearns, E.; Kim, H.; Kyriazopoulou, S.; Lamanna, E.; Lane, C.; Levin, D. S.; Lipari, P.; Longley, N. P.; Longo, M. J.; Loparco, F.; Maaroufi, F.; Mancarella, G.; Mandrioli, G.; Margiotta, A.; Marini, A.; Martello, D.; Marzari-Chiesa, A.; Mazziotta, M. N.; Michael, D. G.; Miller, L.; Monacelli, P.; Montaruli, T.; Monteno, M.; Mufson, S.; Musser, J.; Nicolò, D.; Nolty, R.; Orth, C.; Osteria, G.; Palamara, O.; Patrizii, L.; Pazzi, R.; Peck, C. W.; Perrone, L.; Petrera, S.; Popa, V.; Rainò, A.; Reynoldson, J.; Ronga, F.; Satriano, C.; Scapparone, E.; Scholberg, K.; Serra, P.; Sioli, M.; Sirri, G.; Sitta, M.; Spinelli, P.; Spinetti, M.; Spurio, M.; Steinberg, R.; Stone, J. L.; Sulak, L. R.; Surdo, A.; Tarlè, G.; Togo, V.; Vakili, M.; Walter, C. W.; Webb, R.
2003-02-01
We have analyzed 44.3M single muons collected by MACRO from 1991 through 2000 in 2145 live days of operation. We have searched for the solar diurnal, apparent sidereal, and pseudosidereal modulation of the underground muon rate by computing hourly deviations of the muon rate from 6 month averages. We find evidence for statistically significant modulations with the solar diurnal and the sidereal periods. The amplitudes of these modulations are <0.1%, and are at the limit of the detector statistics. The pseudosidereal modulation is not statistically significant. The solar diurnal modulation is due to the daily atmospheric temperature variations at 20 km, the altitude of primary cosmic ray interactions with the atmosphere; MACRO is the deepest experiment to report this result. The sidereal modulation is in addition to the expected Compton-Getting modulation due to solar system motion relative to the local standard of rest; it represents motion of the solar system with respect to the galactic cosmic rays toward the galactic plane.
Changing world extreme temperature statistics
NASA Astrophysics Data System (ADS)
Finkel, J. M.; Katz, J. I.
2018-04-01
We use the Global Historical Climatology Network--daily database to calculate a nonparametric statistic that describes the rate at which all-time daily high and low temperature records have been set in nine geographic regions (continents or major portions of continents) during periods mostly from the mid-20th Century to the present. This statistic was defined in our earlier work on temperature records in the 48 contiguous United States. In contrast to this earlier work, we find that in every region except North America all-time high records were set at a rate significantly (at least $3\\sigma$) higher than in the null hypothesis of a stationary climate. Except in Antarctica, all-time low records were set at a rate significantly lower than in the null hypothesis. In Europe, North Africa and North Asia the rate of setting new all-time highs increased suddenly in the 1990's, suggesting a change in regional climate regime; in most other regions there was a steadier increase.
Exploring Attitudes of Indian Classical Singers Toward Seeking Vocal Health Care.
Gunjawate, Dhanshree R; Aithal, Venkataraja U; Guddattu, Vasudeva; Kishore, Amrutha; Bellur, Rajashekhar
2016-11-01
The attitude of Indian classical singers toward seeking vocal health care is a dimension yet to be explored. The current study was aimed to determine the attitudes of these singers toward seeking vocal health care and further understand the influence of age and gender. Cross-sectional. A 10-item self-report questionnaire adapted from a study on contemporary commercial music singers was used. An additional question was added to ask if the singer was aware about the profession and role of speech-language pathologists (SLPs). The questionnaire was administered on 55 randomly selected self-identified trained Indian classical singers who rated the items using a five-point Likert scale. Demographic variables were summarized using descriptive statistics and t test was used to compare the mean scores between genders and age groups. Of the singers, 78.2% were likely to see a doctor for heath-related problems, whereas 81.8% were unlikely to seek medical care for voice-related problems; the difference was statistically significant (P < 0.001). Responses for the questions assessing the attitudes toward findings from medical examination by a specialist revealed a statistically significant difference (P = 0.02) between the genders. Age did not have a significant influence on the responses. Only 23.6% of the respondents were aware about the profession and the role of SLPs. The findings are in tune with western literature reporting hesitation of singers toward seeking vocal health care and draws attention of SLPs to promote their role in vocal health awareness and management. Copyright © 2016 The Voice Foundation. Published by Elsevier Inc. All rights reserved.
Changes in jawbones of male patients with chronic renal failure on digital panoramic radiographs.
Dagistan, Saadettin; Miloglu, Ozkan; Caglayan, Fatma
2016-01-01
To compare the existence of gonial cortical bone thickness, antegonial index, mandibular canal bone resorption and gonial angle values and pathologies like ground-glass appearance in jawbones and brown tumor in male patients undergoing dialysis due to chronic renal failure and men from the healthy control group on panoramic radiographs. Panoramic radiographs were taken from 80 male individuals in total (40 normal and 40 dialysis patients). Values obtained from the right and left sides of the mandible were summed and their means were calculated. Gonial cortical thickness, antegonial index and gonial angle values were assessed with the Student's t-test, mandibular canal wall resorption with the Chi-square test, and pathologies such as ground-glass appearance and Brown tumor as "available" or "not available." Statistically significant differences were observed among the antegonial index (P < 0.001), gonial cortical bone thickness (P < 0.001), and gonial angle (P < 0.001) values of study and control groups. Besides, mandibular canal wall resorption (P < 0.001) was also statistically significant. In the study group, pathologies with ground-glass appearance were encountered in mandible, but no radiographic findings were observed similar to brown tumor. Compared to the control group, decreases were found in gonial cortical bone thicknesses, antegonial index values, mandibular canal wall resorption, and gonial angle values of the patients receiving dialysis treatment due to chronic renal failure. Although it is not statistically significant, pathology with ground-glass appearance was detected in a patient, but no pathologies like brown tumor were observed. These findings from patients with chronic renal failure must be evaluated in panoramic radiography.
Thombs, Dennis L.; Olds, R. Scott; Bondy, Susan J.; Winchell, Janice; Baliunas, Dolly; Rehm, Jürgen
2009-01-01
Objective: Findings from previous prospective research suggest the association between alcohol use and undergraduate academic performance is negligible. This study was designed to address weaknesses of the past research by relying on objective measures of both drinking and academic performance. Method: A prospective study was conducted with repeated measures of exposure to alcohol linked to institutional academic records. Alcohol data were collected in residence halls at a nonselective, midwestern, public university in the United States. A total of 659 first- and second-year undergraduate students were tracked over the course of 15-week semesters. Results: A statistically significant negative association with semester academic performance was found for different alcohol indicators: frequency of breath alcohol concentration (BrAC) above .08, mean BrAC, standard deviation, and maximum BrAC recorded. These associations remained statistically significant when controlled for sociodemographic variables and individual level confounders, but the effect sizes were relatively small with a contribution to explained variance of less than 1%. When additionally adjusted for residence hall building, all alcohol indicators no longer reached statistical significance (p ≥ .05). Conclusions: Consistent with past prospective research, the magnitude of the association between undergraduate alcohol use and academic performance is small when the effects of high school academic aptitude and performance are accounted for in multivariable analyses. This is the first study to find that living environment may have a robust effect on the academic achievement of undergraduates. Future research should examine more closely the relation between residence and academic performance and the role that alcohol use may play in creating residential environments. PMID:19737503
Results of Observational Studies: Analysis of Findings from the Nurses’ Health Study
Tai, Vicky; Grey, Andrew; Bolland, Mark J.
2014-01-01
Background The role of observational studies in informing clinical practice is debated, and high profile examples of discrepancies between the results of observational studies and randomised controlled trials (RCTs) have intensified that debate. We systematically reviewed findings from the Nurses’ Health Study (NHS), one of the longest and largest observational studies, to assess the number and strength of the associations reported and to determine if they have been confirmed in RCTs. Methods We reviewed NHS publication abstracts from 1978–2012, extracted information on associations tested, and graded the strength of the reported effect sizes. We searched PubMed for RCTs or systematic reviews for 3 health outcomes commonly reported in NHS publications: breast cancer, ischaemic heart disease (IHD) and osteoporosis. NHS results were compared with RCT results and deemed concordant when the difference in effect sizes between studies was ≤0.15. Findings 2007 associations between health outcomes and independent variables were reported in 1053 abstracts. 58.0% (1165/2007) were statistically significant, and 22.2% (445/2007) were neutral (no association). Among the statistically significant results that reported a numeric odds ratio (OR) or relative risk (RR), 70.5% (706/1002) reported a weak association (OR/RR 0.5–2.0), 24.5% (246/1002) a moderate association (OR/RR 0.25–0.5 or 2.0–4.0) and 5.0% (50/1002) a strong association (OR/RR ≤0.25 or ≥4.0). 19 associations reported in NHS publications for breast cancer, IHD and osteoporosis have been tested in RCTs, and the concordance between NHS and RCT results was low (≤25%). Conclusions NHS publications contain a large number of analyses, the majority of which reported statistically significant but weak associations. Few of these associations have been tested in RCTs, and where they have, the agreement between NHS results and RCTs is poor. PMID:25330007
Pneumoconiosis in different sectors and their differences in Turkey.
Alıcı, Nur Şafak; Çımrın, Arif; Coşkun Beyan, Ayşe
2016-12-01
Pneumoconiosis which is one of the ancient diseases, still affects many workers throughout the world despite "existing" control programs. We add data from a single center reviewing risk factors for pneumoconiosis; evaluate functional and radiological findings in different sectors. We reviewed medical records of patients diagnosed with pneumoconiosis who were admitted to our center between the years 2013 and 2015. Several personal and occupational features, together with functional and radiologic data, were collected. 60 were young males. Twenty-four of the cases (39.3%) worked at dental technician, 24 cases (39.3%) were ceramic workers, 5 cases (8.2%) were sandblasters, 2 cases (3.3%) were welders, 3 cases (4.9%) were miners, and 3 cases (4.9%) were marble cutters. The sectors in which the exposure started at the earliest ages were dental technicians and sandblasters, while the shortest working time was in sandblasting. The dental technicians were younger than the ceramic workers at the age of diagnosis (Kruskall-Wallis p= 0.003). The exposure time of the sandblasters was significantly shorter, especially than the ceramic workers (Kruskall-Wallis p= 0.002). The cases have been referred to us with pneumoconiosis suspicion based on the radiographic findings in the PA chest roentgenogram performed during the periodic examinations at their work place; but unlike other studies, in our study, following the HRCT assessment, cases which did not present any visible pathology in the re-evaluation of their PA chest roentgenogram, but had HRCT findings have been diagnosed as pneumoconiosis. Among the 44 cases in which micro-nodules had been detected at their HRCT, 15 of them had been previously classified as profusion of small opacities 0/1 according to their PA chest roentgenogram findings. It has been seen that the HRCT findings differ among sectors. Ceramics workers and sandblasters had significantly more micro-nodules, while dental technicians had significantly more mediastinal lymphadenopathies (Chi square, p= 0.004 and p= 0.007 respectively). When the relationship between the existence of big opacities and complaints was studied, statistically significant weight loss was detected in cases which had C opacities (chi square p= 0.01). Statistically significant FEV1 decrease was observed in cases which had weight loss (independent samples t-test p= 0.046). It has been observed that when the profusion of small opacities increased, while there was no statistically significant functional status change in non-smokers, a significant functional impairment was observed in smokers. Pneumoconiosis still exists in Turkey. Even a short exposure time as 2 years can cause pneumoconiosis. Workers in different sectors had different functional, radiological properties and smoking can affect the diseases' course. There are serious limitations related to the surveillance of both the workplace environment and the employees' health in Turkey. Without institutional preventive measures, personal protection and surveillance examinations, occupational hazards will continue to cause premature deaths. Pneumoconiosis in different sectors is a prototype of uncontrolled industry in the developing world.
NASA Astrophysics Data System (ADS)
Pearl, Judea
2000-03-01
Written by one of the pre-eminent researchers in the field, this book provides a comprehensive exposition of modern analysis of causation. It shows how causality has grown from a nebulous concept into a mathematical theory with significant applications in the fields of statistics, artificial intelligence, philosophy, cognitive science, and the health and social sciences. Pearl presents a unified account of the probabilistic, manipulative, counterfactual and structural approaches to causation, and devises simple mathematical tools for analyzing the relationships between causal connections, statistical associations, actions and observations. The book will open the way for including causal analysis in the standard curriculum of statistics, artifical intelligence, business, epidemiology, social science and economics. Students in these areas will find natural models, simple identification procedures, and precise mathematical definitions of causal concepts that traditional texts have tended to evade or make unduly complicated. This book will be of interest to professionals and students in a wide variety of fields. Anyone who wishes to elucidate meaningful relationships from data, predict effects of actions and policies, assess explanations of reported events, or form theories of causal understanding and causal speech will find this book stimulating and invaluable.
Statistical significance of combinatorial regulations
Terada, Aika; Okada-Hatakeyama, Mariko; Tsuda, Koji; Sese, Jun
2013-01-01
More than three transcription factors often work together to enable cells to respond to various signals. The detection of combinatorial regulation by multiple transcription factors, however, is not only computationally nontrivial but also extremely unlikely because of multiple testing correction. The exponential growth in the number of tests forces us to set a strict limit on the maximum arity. Here, we propose an efficient branch-and-bound algorithm called the “limitless arity multiple-testing procedure” (LAMP) to count the exact number of testable combinations and calibrate the Bonferroni factor to the smallest possible value. LAMP lists significant combinations without any limit, whereas the family-wise error rate is rigorously controlled under the threshold. In the human breast cancer transcriptome, LAMP discovered statistically significant combinations of as many as eight binding motifs. This method may contribute to uncover pathways regulated in a coordinated fashion and find hidden associations in heterogeneous data. PMID:23882073
Besiroglu, Lutfullah; Çetinkaya, Nuralay; Selvi, Yavuz; Atli, Abdullah
2011-01-01
We aimed to assess whether cognitive processes change over time in patients with obsessive-compulsive disorder (OCD) receiving selective serotonin reuptake inhibitors without cognitive behavioral therapy and to investigate the factors associated with probable cognitive changes. During the 16 weeks of the study, 55 patients who met the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria for OCD received open-label treatment with sertraline (100-200 mg/d) or fluoxetine (40-80 mg/d) and were assessed using the Yale-Brown Obsessive-Compulsive Scale, Beck Depression Inventory (BDI), Thought-Action Fusion Scale (TAFS), Metacognitions Questionnaire (MCQ-30), and White Bear Suppression Inventory (WBSI). The Yale-Brown Obsessive-Compulsive Scale (P < .001), BDI (P < .001), TAFS morality (P < .005), MCQ-30 (P < .01), and WBSI (P < .005) scores at follow-up were significantly lower than baseline scores. When we excluded OCD patients with depressive disorder (n = 12), statistical significance in paired comparisons for MCQ and WBSI disappeared. Similarly, when OCD patients with religious obsessions (n = 16) were excluded, paired comparisons for MCQ and TAF morality were not statistically significant. Changes in BDI, TAFS morality, MCQ-30, and WBSI (P < .005) were significantly correlated with changes in severity of obsessions, but not that of compulsions. After controlling for the change in depression severity, significant correlations between changes in obsessive and cognitive scales did not continue to have statistical significance. The BDI changes (P < .05) significantly explained the changes in symptom severity in a linear regression model. Our findings suggest that selective serotonin reuptake inhibitors can change appraisals of obsessive intrusions via their effects on negative emotions. Copyright © 2011 Elsevier Inc. All rights reserved.
CT findings of pulmonary tuberculosis and tuberculous pleurisy in diabetes mellitus patients.
Kim, Jihyun; Lee, In Jae; Kim, Joo Hee
2017-01-01
We aimed to assess computed tomography (CT) findings of pulmonary tuberculosis (TB) and TB pleurisy in diabetes mellitus (DM) patients and to evaluate the effect of duration of DM on radiologic findings of pulmonary TB and TB pleurisy. Ninety-three consecutive patients diagnosed as active pulmonary TB with underlying DM were enrolled in our study. As a control group, 100 pulmonary TB patients without DM were randomly selected. TB patients with DM were subdivided into two subgroups depending on diabetes duration of ≥10 years or <10 years. Medical records and CT scans of the patients were retrospectively reviewed and compared. Bilateral pulmonary involvement (odds ratio [OR]=2.39, P = 0.003), involvement of all lobes (OR=2.79, P = 0.013), and lymph node enlargement (OR=1.98, P = 0.022) were significantly more frequent CT findings among TB patients with DM compared with the controls. There were no statistically significant differences in CT findings of pulmonary TB depending on the duration of DM. Bilateral pulmonary involvement, involvement of all lobes, and lymph node enlargement are significantly more common CT findings in TB patients with underlying DM than in patients without DM. Familiarity with the CT findings may be helpful to suggest prompt diagnosis of pulmonary TB in DM patients.
Cao, Hui; Markatou, Marianthi; Melton, Genevieve B.; Chiang, Michael F.; Hripcsak, George
2005-01-01
This paper applies co-occurrence statistics to discover disease-finding associations in a clinical data warehouse. We used two methods, χ2 statistics and the proportion confidence interval (PCI) method, to measure the dependence of pairs of diseases and findings, and then used heuristic cutoff values for association selection. An intrinsic evaluation showed that 94 percent of disease-finding associations obtained by χ2 statistics and 76.8 percent obtained by the PCI method were true associations. The selected associations were used to construct knowledge bases of disease-finding relations (KB-χ2, KB-PCI). An extrinsic evaluation showed that both KB-χ2 and KB-PCI could assist in eliminating clinically non-informative and redundant findings from problem lists generated by our automated problem list summarization system. PMID:16779011
Marvel, Skylar W; Rotroff, Daniel M; Wagner, Michael J; Buse, John B; Havener, Tammy M; McLeod, Howard L; Motsinger-Reif, Alison A
2017-01-01
Individuals with type 2 diabetes are at an increased risk of cardiovascular disease. Alterations in circulating lipid levels, total cholesterol (TC), low-density lipoprotein (LDL), high-density lipoprotein (HDL), and triglycerides (TG) are heritable risk factors for cardiovascular disease. Here we conduct a genome-wide association study (GWAS) of common and rare variants to investigate associations with baseline lipid levels in 7,844 individuals with type 2 diabetes from the ACCORD clinical trial. DNA extracted from stored blood samples from ACCORD participants were genotyped using the Affymetrix Axiom Biobank 1 Genotyping Array. After quality control and genotype imputation, association of common genetic variants (CV), defined as minor allele frequency (MAF) ≥ 3%, with baseline levels of TC, LDL, HDL, and TG was tested using a linear model. Rare variant (RV) associations (MAF < 3%) were conducted using a suite of methods that collapse multiple RV within individual genes. Many statistically significant CV ( p < 1 × 10 -8 ) replicate findings in large meta-analyses in non-diabetic subjects. RV analyses also confirmed findings in other studies, whereas significant RV associations with CNOT2 , HPN-AS1 , and SIRPD appear to be novel ( q < 0.1). Here we present findings for the largest GWAS of lipid levels in people with type 2 diabetes to date. We identified 17 statistically significant ( p < 1 × 10 -8 ) associations of CV with lipid levels in 11 genes or chromosomal regions, all of which were previously identified in meta-analyses of mostly non-diabetic cohorts. We also identified 13 associations in 11 genes based on RV, several of which represent novel findings.
Wagner, Michael J.; Buse, John B.; Havener, Tammy M.; McLeod, Howard L.
2017-01-01
Background Individuals with type 2 diabetes are at an increased risk of cardiovascular disease. Alterations in circulating lipid levels, total cholesterol (TC), low-density lipoprotein (LDL), high-density lipoprotein (HDL), and triglycerides (TG) are heritable risk factors for cardiovascular disease. Here we conduct a genome-wide association study (GWAS) of common and rare variants to investigate associations with baseline lipid levels in 7,844 individuals with type 2 diabetes from the ACCORD clinical trial. Methods DNA extracted from stored blood samples from ACCORD participants were genotyped using the Affymetrix Axiom Biobank 1 Genotyping Array. After quality control and genotype imputation, association of common genetic variants (CV), defined as minor allele frequency (MAF) ≥ 3%, with baseline levels of TC, LDL, HDL, and TG was tested using a linear model. Rare variant (RV) associations (MAF < 3%) were conducted using a suite of methods that collapse multiple RV within individual genes. Results Many statistically significant CV (p < 1 × 10−8) replicate findings in large meta-analyses in non-diabetic subjects. RV analyses also confirmed findings in other studies, whereas significant RV associations with CNOT2, HPN-AS1, and SIRPD appear to be novel (q < 0.1). Discussion Here we present findings for the largest GWAS of lipid levels in people with type 2 diabetes to date. We identified 17 statistically significant (p < 1 × 10−8) associations of CV with lipid levels in 11 genes or chromosomal regions, all of which were previously identified in meta-analyses of mostly non-diabetic cohorts. We also identified 13 associations in 11 genes based on RV, several of which represent novel findings. PMID:28480134
Association between erectile dysfunction and chronic periodontitis: a clinical study.
Uppal, Ranjit Singh; Bhandari, Rajat; Singh, Karanparkash
2014-01-01
In recent years, evidence has come forth supporting the notion that localized infectious diseases such as periodontal disease may indeed influence a number of systemic diseases. Erectile dysfunction (ED) and chronic periodontitis have common risk factors such as diabetes mellitus, cardiac diseases and smoking etc. The aim was to evaluate the periodontal status of the subjects suffering from ED and to find association between vasculogenic ED and chronic periodontitis, if any. A total of 53 subjects suffering from vasculogenic ED were enrolled for the study and were divided into three groups on the basis of severity of ED. The clinical (probing pocket depth) and radiographic parameters (alveolar bone loss) were recorded and periodontal status of three groups was evaluated, compared and an attempt was made to find an association between ED and chronic periodontitis. Karl Pearson's correlation was used to assess an association between the two conditions. One-way ANOVA and Scheffe's test were used to find the significant difference of chronic periodontitis with severity of ED. Karl Pearson's correlation was used to find an association between chronic periodontitis and ED. Statistically significant mean differences of 1.73 mm, 0.56 mm and 1.17 mm were recorded when comparison was made among Group I and III, Group I and II and Group II and III, respectively. Mean differences in bone loss among three groups were also statistically significant. Both the diseases were positively correlated to each other. It may be concluded that chronic periodontitis and ED are associated with each other. However, further large scale studies with confounder analysis and longitudinal follow-up are warranted to explore the link between these two diseases.
Ocular findings in coal miners diagnosed with pneumoconiosis.
Ayar, Orhan; Orcun Akdemir, Mehmet; Erboy, Fatma; Yazgan, Serpil; Hayri Ugurbas, Suat
2017-06-01
Our study aimed at evaluating ocular findings and structural changes in coal mine workers who were chronically exposed to coal mine dust and diagnosed with pneumoconiosis. Ocular findings of 161 eyes of 81 patients diagnosed with pneumoconiosis who had previously worked or are currently working in coal mines were analyzed. Forty-six coal mine workers and sex matched healthy people (n = 20) participated in the study. Workers who had early changes of pneumoconiosis were included in Group 1 (n = 17), workers diagnosed with pneumoconiosis were included in Group 2 (n = 29), and healthy subjects were included in Group 3 (n = 20). Outcome measures were the difference in peripapillary retinal nerve fiber layer (RNFL) thickness, choroidal thickness (CT), central macular thickness (CMT) and tear function tests between the groups. RNFL thickness values in Group 1 and 2 were lower than in Group 3, the control group, in all quadrants except the temporal quadrant. However, there was no statistically significant difference in peripapillary RNFL thickness values in any quadrants among the three groups (p > 0.05). Central subfoveal choroidal thickness and CMT measurements were thinner in Group 1 and 2 than in the control group. However, this difference among groups was not statistically significant (p > 0.05). Mean schirmer's test result was 8.8 ± 1.6 mm in group 1, 7.1 ± 1.8 mm in Group 2 and 11.5 ± 3.6 mm in the control group. Mean tear break up time (BUT) test result was 7.1 ± 1.3 seconds (sec) in Group 1, 6.5 ± 1.8 sec in Group 2 and 10.4 ± 2.9 s in the control group. The Schirmer's test and BUT test results were both statistically significantly lower in coal mine workers (Group 1 and 2) compared to the control group. Group 1 and Group 2 did not show statistically significant difference in terms of Schirmer's test and BUT test results. The association between pneumoconiosis and coal mine dust contiguity is thought to be due to the effect of coal dust by producing chronic inflammation. In addition, there are several trace elements in coal dust which are toxic to vital tissues. In this study, ocular findings suggest that systemic levels of trace elements and chronic inflammation may not reach to a level that influences ocular structures. Nonetheless, tear functions seem to be affected in coal mine workers. This study suggests that the systemic effect of coal mine dust in ocular structures is not evident. However, direct contact with coal mine and fume leads to a decrease in tear function tests.
Diedrich, Alice; Schlegl, Sandra; Greetfeld, Martin; Fumi, Markus; Voderholzer, Ulrich
2018-03-01
This study examines the statistical and clinical significance of symptom changes during an intensive inpatient treatment program with a strong psychotherapeutic focus for individuals with severe bulimia nervosa. 295 consecutively admitted bulimic patients were administered the Structured Interview for Anorexic and Bulimic Syndromes-Self-Rating (SIAB-S), the Eating Disorder Inventory-2 (EDI-2), the Brief Symptom Inventory (BSI), and the Beck Depression Inventory-II (BDI-II) at treatment intake and discharge. Results indicated statistically significant symptom reductions with large effect sizes regarding severity of binge eating and compensatory behavior (SIAB-S), overall eating disorder symptom severity (EDI-2), overall psychopathology (BSI), and depressive symptom severity (BDI-II) even when controlling for antidepressant medication. The majority of patients showed either reliable (EDI-2: 33.7%, BSI: 34.8%, BDI-II: 18.1%) or even clinically significant symptom changes (EDI-2: 43.2%, BSI: 33.9%, BDI-II: 56.9%). Patients with clinically significant improvement were less distressed at intake and less likely to suffer from a comorbid borderline personality disorder when compared with those who did not improve to a clinically significant extent. Findings indicate that intensive psychotherapeutic inpatient treatment may be effective in about 75% of severely affected bulimic patients. For the remaining non-responding patients, inpatient treatment might be improved through an even stronger focus on the reduction of comorbid borderline personality traits.
NASA Astrophysics Data System (ADS)
Shih, A. L.; Liu, J. Y. G.
2015-12-01
A median-based method and a z test are employed to find characteristics of seismo-ionospheric precursor (SIP) of the total electron content (TEC) in global ionosphere map (GIM) associated with 129 M≥5.5 earthquakes in Taiwan during 1999-2014. Results show that both negative and positive anomalies in the GIM TEC with the statistical significance of the z test appear few days before the earthquakes. The receiver operating characteristic (ROC) curve is further applied to see whether the SIPs exist in Taiwan.
Whose statistical reasoning is facilitated by a causal structure intervention?
McNair, Simon; Feeney, Aidan
2015-02-01
People often struggle when making Bayesian probabilistic estimates on the basis of competing sources of statistical evidence. Recently, Krynski and Tenenbaum (Journal of Experimental Psychology: General, 136, 430-450, 2007) proposed that a causal Bayesian framework accounts for peoples' errors in Bayesian reasoning and showed that, by clarifying the causal relations among the pieces of evidence, judgments on a classic statistical reasoning problem could be significantly improved. We aimed to understand whose statistical reasoning is facilitated by the causal structure intervention. In Experiment 1, although we observed causal facilitation effects overall, the effect was confined to participants high in numeracy. We did not find an overall facilitation effect in Experiment 2 but did replicate the earlier interaction between numerical ability and the presence or absence of causal content. This effect held when we controlled for general cognitive ability and thinking disposition. Our results suggest that clarifying causal structure facilitates Bayesian judgments, but only for participants with sufficient understanding of basic concepts in probability and statistics.
Therapies for acute myeloid leukemia: vosaroxin
Sayar, Hamid; Bashardoust, Parvaneh
2017-01-01
Vosaroxin, a quinolone-derivative chemotherapeutic agent, was considered a promising drug for the treatment of acute myeloid leukemia (AML). Early-stage clinical trials with this agent led to a large randomized double-blind placebo-controlled study of vosaroxin in combination with intermediate-dose cytarabine for the treatment of relapsed or refractory AML. The study demonstrated better complete remission rates with vosaroxin, but there was no statistically significant overall survival benefit in the whole cohort. A subset analysis censoring patients who had undergone allogeneic stem cell transplantation, however, revealed a modest but statistically significant improvement in overall survival particularly among older patients. This article reviews the data available on vosaroxin including clinical trials in AML and offers an analysis of findings of these studies as well as the current status of vosaroxin. PMID:28860803
Therapies for acute myeloid leukemia: vosaroxin.
Sayar, Hamid; Bashardoust, Parvaneh
2017-01-01
Vosaroxin, a quinolone-derivative chemotherapeutic agent, was considered a promising drug for the treatment of acute myeloid leukemia (AML). Early-stage clinical trials with this agent led to a large randomized double-blind placebo-controlled study of vosaroxin in combination with intermediate-dose cytarabine for the treatment of relapsed or refractory AML. The study demonstrated better complete remission rates with vosaroxin, but there was no statistically significant overall survival benefit in the whole cohort. A subset analysis censoring patients who had undergone allogeneic stem cell transplantation, however, revealed a modest but statistically significant improvement in overall survival particularly among older patients. This article reviews the data available on vosaroxin including clinical trials in AML and offers an analysis of findings of these studies as well as the current status of vosaroxin.
Statistics of Magnetic Reconnection X-Lines in Kinetic Turbulence
NASA Astrophysics Data System (ADS)
Haggerty, C. C.; Parashar, T.; Matthaeus, W. H.; Shay, M. A.; Wan, M.; Servidio, S.; Wu, P.
2016-12-01
In this work we examine the statistics of magnetic reconnection (x-lines) and their associated reconnection rates in intermittent current sheets generated in turbulent plasmas. Although such statistics have been studied previously for fluid simulations (e.g. [1]), they have not yet been generalized to fully kinetic particle-in-cell (PIC) simulations. A significant problem with PIC simulations, however, is electrostatic fluctuations generated due to numerical particle counting statistics. We find that analyzing gradients of the magnetic vector potential from the raw PIC field data identifies numerous artificial (or non-physical) x-points. Using small Orszag-Tang vortex PIC simulations, we analyze x-line identification and show that these artificial x-lines can be removed using sub-Debye length filtering of the data. We examine how turbulent properties such as the magnetic spectrum and scale dependent kurtosis are affected by particle noise and sub-Debye length filtering. We subsequently apply these analysis methods to a large scale kinetic PIC turbulent simulation. Consistent with previous fluid models, we find a range of normalized reconnection rates as large as ½ but with the bulk of the rates being approximately less than to 0.1. [1] Servidio, S., W. H. Matthaeus, M. A. Shay, P. A. Cassak, and P. Dmitruk (2009), Magnetic reconnection and two-dimensional magnetohydrodynamic turbulence, Phys. Rev. Lett., 102, 115003.
Statistics of Low-Mass Companions to Stars: Implications for Their Origin
NASA Technical Reports Server (NTRS)
Stepinski, T. F.; Black, D. C.
2001-01-01
One of the more significant results from observational astronomy over the past few years has been the detection, primarily via radial velocity studies, of low-mass companions (LMCs) to solar-like stars. The commonly held interpretation of these is that the majority are "extrasolar planets" whereas the rest are brown dwarfs, the distinction made on the basis of apparent discontinuity in the distribution of M sin i for LMCs as revealed by a histogram. We report here results from statistical analysis of M sin i, as well as of the orbital elements data for available LMCs, to rest the assertion that the LMCs population is heterogeneous. The outcome is mixed. Solely on the basis of the distribution of M sin i a heterogeneous model is preferable. Overall, we find that a definitive statement asserting that LMCs population is heterogeneous is, at present, unjustified. In addition we compare statistics of LMCs with a comparable sample of stellar binaries. We find a remarkable statistical similarity between these two populations. This similarity coupled with marked populational dissimilarity between LMCs and acknowledged planets motivates us to suggest a common origin hypothesis for LMCs and stellar binaries as an alternative to the prevailing interpretation. We discuss merits of such a hypothesis and indicate a possible scenario for the formation of LMCs.
Simmons, Joseph P; Nelson, Leif D; Simonsohn, Uri
2011-11-01
In this article, we accomplish two things. First, we show that despite empirical psychologists' nominal endorsement of a low rate of false-positive findings (≤ .05), flexibility in data collection, analysis, and reporting dramatically increases actual false-positive rates. In many cases, a researcher is more likely to falsely find evidence that an effect exists than to correctly find evidence that it does not. We present computer simulations and a pair of actual experiments that demonstrate how unacceptably easy it is to accumulate (and report) statistically significant evidence for a false hypothesis. Second, we suggest a simple, low-cost, and straightforwardly effective disclosure-based solution to this problem. The solution involves six concrete requirements for authors and four guidelines for reviewers, all of which impose a minimal burden on the publication process.
Chromosome breakage in humans exposed to methyl mercury through fish consumption
DOE Office of Scientific and Technical Information (OSTI.GOV)
Skerfving, S.; Hansson, K.; Lindsten, J.
1980-08-01
Chromosome analysis was performed on cells from lymphocyte cultures from nine subjects with increased levels of mercury in their red blood cells and in four healthy controls. The elevated mercury levels were likely to have originated from dietary fish with high levels of methyl mercury. A statistically significant rank correlation was found between the frequency of cells with chromosome breaks and mercury concentration. The biological significance of these findings is at present unknown.
2013-01-01
Background Malnutrition is one of the principal causes of child mortality in developing countries including Bangladesh. According to our knowledge, most of the available studies, that addressed the issue of malnutrition among under-five children, considered the categorical (dichotomous/polychotomous) outcome variables and applied logistic regression (binary/multinomial) to find their predictors. In this study malnutrition variable (i.e. outcome) is defined as the number of under-five malnourished children in a family, which is a non-negative count variable. The purposes of the study are (i) to demonstrate the applicability of the generalized Poisson regression (GPR) model as an alternative of other statistical methods and (ii) to find some predictors of this outcome variable. Methods The data is extracted from the Bangladesh Demographic and Health Survey (BDHS) 2007. Briefly, this survey employs a nationally representative sample which is based on a two-stage stratified sample of households. A total of 4,460 under-five children is analysed using various statistical techniques namely Chi-square test and GPR model. Results The GPR model (as compared to the standard Poisson regression and negative Binomial regression) is found to be justified to study the above-mentioned outcome variable because of its under-dispersion (variance < mean) property. Our study also identify several significant predictors of the outcome variable namely mother’s education, father’s education, wealth index, sanitation status, source of drinking water, and total number of children ever born to a woman. Conclusions Consistencies of our findings in light of many other studies suggest that the GPR model is an ideal alternative of other statistical models to analyse the number of under-five malnourished children in a family. Strategies based on significant predictors may improve the nutritional status of children in Bangladesh. PMID:23297699
Testing for X-Ray–SZ Differences and Redshift Evolution in the X-Ray Morphology of Galaxy Clusters
DOE Office of Scientific and Technical Information (OSTI.GOV)
Nurgaliev, D.; McDonald, M.; Benson, B. A.
We present a quantitative study of the X-ray morphology of galaxy clusters, as a function of their detection method and redshift. We analyze two separate samples of galaxy clusters: a sample of 36 clusters atmore » $$0.35\\lt z\\lt 0.9$$ selected in the X-ray with the ROSAT PSPC 400 deg(2) survey, and a sample of 90 clusters at $$0.25\\lt z\\lt 1.2$$ selected via the Sunyaev–Zel’dovich (SZ) effect with the South Pole Telescope. Clusters from both samples have similar-quality Chandra observations, which allow us to quantify their X-ray morphologies via two distinct methods: centroid shifts (w) and photon asymmetry ($${A}_{\\mathrm{phot}}$$). The latter technique provides nearly unbiased morphology estimates for clusters spanning a broad range of redshift and data quality. We further compare the X-ray morphologies of X-ray- and SZ-selected clusters with those of simulated clusters. We do not find a statistically significant difference in the measured X-ray morphology of X-ray and SZ-selected clusters over the redshift range probed by these samples, suggesting that the two are probing similar populations of clusters. We find that the X-ray morphologies of simulated clusters are statistically indistinguishable from those of X-ray- or SZ-selected clusters, implying that the most important physics for dictating the large-scale gas morphology (outside of the core) is well-approximated in these simulations. Finally, we find no statistically significant redshift evolution in the X-ray morphology (both for observed and simulated clusters), over the range of $$z\\sim 0.3$$ to $$z\\sim 1$$, seemingly in contradiction with the redshift-dependent halo merger rate predicted by simulations.« less
Aihara, Takatsugu; Ogawa, Takeshi; Shimokawa, Takeaki; Yamashita, Okito
2017-01-01
Humans often utilize past experience to solve difficult problems. However, if past experience is insufficient to solve a problem, solvers may reach an impasse. Insight can be valuable for breaking an impasse, enabling the reinterpretation or re-representation of a problem. Previous studies using between-subjects designs have revealed a causal relationship between the anterior temporal lobes (ATLs) and non-verbal insight, by enhancing the right ATL while inhibiting the left ATL using transcranial direct current stimulation (tDCS). In addition, neuroimaging studies have reported a correlation between right ATL activity and verbal insight. Based on these findings, we hypothesized that the right ATL is causally related to both non-verbal and verbal insight. To test this hypothesis, we conducted an experiment with 66 subjects using a within-subjects design, which typically has greater statistical power than a between-subjects design. Subjects participated in tDCS experiments across 2 days, in which they solved both non-verbal and verbal insight problems under active or sham stimulation conditions. To dissociate the effects of right ATL stimulation from those of left ATL stimulation, we used two montage types; anodal tDCS of the right ATL together with cathodal tDCS of the left ATL (stimulating both ATLs) and anodal tDCS of the right ATL with cathodal tDCS of the left cheek (stimulating only the right ATL). The montage used was counterbalanced across subjects. Statistical analyses revealed that, regardless of the montage type, there were no significant differences between the active and sham conditions for either verbal or non-verbal insight, although the finding for non-verbal insight was inconclusive because of a lack of statistical power. These results failed to support previous findings suggesting that the right ATL is the central locus of insight.
Testing for X-Ray–SZ Differences and Redshift Evolution in the X-Ray Morphology of Galaxy Clusters
Nurgaliev, D.; McDonald, M.; Benson, B. A.; ...
2017-05-16
We present a quantitative study of the X-ray morphology of galaxy clusters, as a function of their detection method and redshift. We analyze two separate samples of galaxy clusters: a sample of 36 clusters atmore » $$0.35\\lt z\\lt 0.9$$ selected in the X-ray with the ROSAT PSPC 400 deg(2) survey, and a sample of 90 clusters at $$0.25\\lt z\\lt 1.2$$ selected via the Sunyaev–Zel’dovich (SZ) effect with the South Pole Telescope. Clusters from both samples have similar-quality Chandra observations, which allow us to quantify their X-ray morphologies via two distinct methods: centroid shifts (w) and photon asymmetry ($${A}_{\\mathrm{phot}}$$). The latter technique provides nearly unbiased morphology estimates for clusters spanning a broad range of redshift and data quality. We further compare the X-ray morphologies of X-ray- and SZ-selected clusters with those of simulated clusters. We do not find a statistically significant difference in the measured X-ray morphology of X-ray and SZ-selected clusters over the redshift range probed by these samples, suggesting that the two are probing similar populations of clusters. We find that the X-ray morphologies of simulated clusters are statistically indistinguishable from those of X-ray- or SZ-selected clusters, implying that the most important physics for dictating the large-scale gas morphology (outside of the core) is well-approximated in these simulations. Finally, we find no statistically significant redshift evolution in the X-ray morphology (both for observed and simulated clusters), over the range of $$z\\sim 0.3$$ to $$z\\sim 1$$, seemingly in contradiction with the redshift-dependent halo merger rate predicted by simulations.« less
Parametric and nonparametric Granger causality testing: Linkages between international stock markets
NASA Astrophysics Data System (ADS)
De Gooijer, Jan G.; Sivarajasingham, Selliah
2008-04-01
This study investigates long-term linear and nonlinear causal linkages among eleven stock markets, six industrialized markets and five emerging markets of South-East Asia. We cover the period 1987-2006, taking into account the on-set of the Asian financial crisis of 1997. We first apply a test for the presence of general nonlinearity in vector time series. Substantial differences exist between the pre- and post-crisis period in terms of the total number of significant nonlinear relationships. We then examine both periods, using a new nonparametric test for Granger noncausality and the conventional parametric Granger noncausality test. One major finding is that the Asian stock markets have become more internationally integrated after the Asian financial crisis. An exception is the Sri Lankan market with almost no significant long-term linear and nonlinear causal linkages with other markets. To ensure that any causality is strictly nonlinear in nature, we also examine the nonlinear causal relationships of VAR filtered residuals and VAR filtered squared residuals for the post-crisis sample. We find quite a few remaining significant bi- and uni-directional causal nonlinear relationships in these series. Finally, after filtering the VAR-residuals with GARCH-BEKK models, we show that the nonparametric test statistics are substantially smaller in both magnitude and statistical significance than those before filtering. This indicates that nonlinear causality can, to a large extent, be explained by simple volatility effects.
The effects of hands-on-science instruction on the science achievement of middle school students
NASA Astrophysics Data System (ADS)
Wiggins, Felita
Student achievement in the Twenty First Century demands a new rigor in student science knowledge, since advances in science and technology require students to think and act like scientists. As a result, students must acquire proficient levels of knowledge and skills to support a knowledge base that is expanding exponentially with new scientific advances. This study examined the effects of hands-on-science instruction on the science achievement of middle school students. More specifically, this study was concerned with the influence of hands-on science instruction versus traditional science instruction on the science test scores of middle school students. The subjects in this study were one hundred and twenty sixth-grade students in six classes. Instruction involved lecture/discussion and hands-on activities carried out for a three week period. Specifically, the study ascertained the influence of the variables gender, ethnicity, and socioeconomic status on the science test scores of middle school students. Additionally, this study assessed the effect of the variables gender, ethnicity, and socioeconomic status on the attitudes of sixth grade students toward science. The two instruments used to collect data for this study were the Prentice Hall unit ecosystem test and the Scientific Work Experience Programs for Teachers Study (SWEPT) student's attitude survey. Moreover, the data for the study was treated using the One-Way Analysis of Covariance and the One-Way Analysis of Variance. The following findings were made based on the results: (1) A statistically significant difference existed in the science performance of middle school students exposed to hands-on science instruction. These students had significantly higher scores than the science performance of middle school students exposed to traditional instruction. (2) A statistically significant difference did not exist between the science scores of male and female middle school students. (3) A statistically significant difference did not exist between the science scores of African American and non-African American middle school students. (4) A statistically significant difference existed in the socioeconomic status of students who were not provided with assisted lunches. Students with unassisted lunches had significantly higher science scores than those middle school students who were provided with assisted lunches. (5) A statistically significant difference was not found in the attitude scores of middle school students who were exposed to hands-on or traditional science instruction. (6) A statistically significant difference was not found in the observed attitude scores of middle school students who were exposed to either hands-on or traditional science instruction by their socioeconomic status. (7) A statistically significant difference was not found in the observed attitude scores of male and female students. (8) A statistically significant difference was not found in the observed attitude scores of African American and non African American students.
Leptin to adiponectin ratio in preeclampsia.
Khosrowbeygi, A; Ahmadvand, H
2013-04-01
The aim of the present study was to assess leptin/adiponectin ratio in preeclamptic patients compared with normal pregnant women. A cross-sectional study was designed. The study population consisted of 30 preeclamptic patients and 30 healthy pregnant women. Serum levels of total leptin and adiponectin were assessed using commercially available enzyme-linked immunosorbent assay methods. The one-way ANOVA and Student's t tests and Pearson's correlation analysis were used for statistical calculations. Levels of leptin and adiponectin were also adjusted for BMI. A p-value < 0.05 was considered statistically significant. The leptin/adiponectin ratio was increased significantly in preeclamptic patients. The leptin/adiponectin ratio was significantly higher in severe preeclamptic patient than in mild preeclampsia. Adjusted leptin/adiponectin ratio was also significantly increased in preeclamptic patients than in normal pregnant women. The findings of the present study suggest that the leptin/adiponectin ratio was increased in preeclamsia and imbalance between the adipocytokines could be involved in the pathogenesis of preeclampsia.
Saurina, Carme; Marzo, Manel; Saez, Marc
2015-09-08
While previous research already exists on the impact of the current economic crisis and whether it leads to an increase in mortality by suicide, our objective in this paper is to determine if the increase in the suicide rate in Catalonia, Spain from 2010 onwards has been statistically significant and whether it is associated with rising unemployment. We used hierarchical mixed models, separately considering the crude death rate of suicides for municipalities with more than and less than 10,000 inhabitants as dependent variables both unstratified and stratified according to gender and/or age group. In municipalities with 10,000 or more inhabitants there was an increase in the relative risk of suicide from 2009 onwards. This increase was only statistically significant for working-aged women (16-64 years). In municipalities with less than 10,000 inhabitants the relative risk showed a decreasing trend even after 2009. In no case did we find the unemployment rate to be associated (statistically significant) with the suicide rate. The increase in the suicide rate from 2010 in Catalonia was not statistically significant as a whole, with the exception of working-aged women (16-64 years) living in municipalities with 10,000 or more inhabitants. We have not found this increase to be associated with rising unemployment in any of the cases. Future research into the effects of economic recessions on suicide mortality should take into account inequalities by age, sex and size of municipalities.
NASA Astrophysics Data System (ADS)
Martin, Lynn A.
The purpose of this study was to examine the relationship between teachers' self-reported preparedness for teaching science content and their instructional practices to the science achievement of eighth grade science students in the United States as demonstrated by TIMSS 2007. Six hundred eighty-seven eighth grade science teachers in the United States representing 7,377 students responded to the TIMSS 2007 questionnaire about their instructional preparedness and their instructional practices. Quantitative data were reported. Through correlation analysis, the researcher found statistically significant positive relationships emerge between eighth grade science teachers' main area of study and their self-reported beliefs about their preparedness to teach that same content area. Another correlation analysis found a statistically significant negative relationship existed between teachers' self-reported use of inquiry-based instruction and preparedness to teach chemistry, physics and earth science. Another correlation analysis discovered a statistically significant positive relationship existed between physics preparedness and student science achievement. Finally, a correlation analysis found a statistically significant positive relationship existed between science teachers' self-reported implementation of inquiry-based instructional practices and student achievement. The data findings support the conclusion that teachers who have feelings of preparedness to teach science content and implement more inquiry-based instruction and less didactic instruction produce high achieving science students. As science teachers obtain the appropriate knowledge in science content and pedagogy, science teachers will feel prepared and will implement inquiry-based instruction in science classrooms.
Chua, Felicia H Z; Thien, Ady; Ng, Lee Ping; Seow, Wan Tew; Low, David C Y; Chang, Kenneth T E; Lian, Derrick W Q; Loh, Eva; Low, Sharon Y Y
2017-03-01
Posterior fossa syndrome (PFS) is a serious complication faced by neurosurgeons and their patients, especially in paediatric medulloblastoma patients. The uncertain aetiology of PFS, myriad of cited risk factors and therapeutic challenges make this phenomenon an elusive entity. The primary objective of this study was to identify associative factors related to the development of PFS in medulloblastoma patient post-tumour resection. This is a retrospective study based at a single institution. Patient data and all related information were collected from the hospital records, in accordance to a list of possible risk factors associated with PFS. These included pre-operative tumour volume, hydrocephalus, age, gender, extent of resection, metastasis, ventriculoperitoneal shunt insertion, post-operative meningitis and radiological changes in MRI. Additional variables included molecular and histological subtypes of each patient's medulloblastoma tumour. Statistical analysis was employed to determine evidence of each variable's significance in PFS permanence. A total of 19 patients with appropriately complete data was identified. Initial univariate analysis did not show any statistical significance. However, multivariate analysis for MRI-specific changes reported bilateral DWI restricted diffusion changes involving both right and left sides of the surgical cavity was of statistical significance for PFS permanence. The authors performed a clinical study that evaluated possible risk factors for permanent PFS in paediatric medulloblastoma patients. Analysis of collated results found that post-operative DWI restriction in bilateral regions within the surgical cavity demonstrated statistical significance as a predictor of PFS permanence-a novel finding in the current literature.
Polyneuropathy and myopathy in beta-thalassemia major patients.
Nemtsas, P; Arnaoutoglou, M; Perifanis, V; Koutsouraki, E; Spanos, G; Arnaoutoglou, N; Chalkia, P; Pantelidou, D; Orologas, A
2018-05-01
The thalassemias are the most common single gene disorder in the world. Nowadays, the average life expectancy of patients in developed countries has increased significantly, while, there was an increase of complications. We aimed to investigate peripheral neuropathy and myopathy in this patient group using a neurophysiological study. We performed nerve conduction studies and electromyography of upper and lower extremities on 36 beta-thalassemia major (β-thal) patients. The electrophysiological findings were correlated with demographic data and laboratory parameters of the disease. Patients with β-thal present polyneuropathy or myopathy at (50%). Polyneuropathy was detected in (38.9%) and myopathy in (27.8%), while polyneuropathy and myopathy were present at (16.7%) with an overlap of the diseases in 1/3 of the patients. There was not a statistically significant correlation of polyneuropathy and myopathy with age, sex, splenectomy, nor with respect to laboratory parameters, hemoglobin, and ferritin. However, there was a statistically significant correlation of polyneuropathy and myopathy with iron overload, as recorded by the magnetic resonance imaging (MRI) of the heart and the liver. Our findings suggest that iron overload plays a key role in the pathogenesis of polyneuropathy and myopathy in β-thal patients, and performing heart and liver MRI for the prediction of such lesions in an annual basis is warranted.
Mohamed, Salem Y; Emara, Mohamed H; Hussien, Hala IM; Elsadek, Hany M
2016-01-01
Aim: Assessment of short term changes in portal blood flow and long term changes in liver functions in cirrhotic patients who chose to fast during the month of Ramadan in summer. Background: During Ramadan, healthy Muslims obligated to fast from predawn to sunset. Patients and methods: Forty cirrhotic patients intended to fast during the month of Ramadan in the year 2014, were examined by Congestion index (CI) as a non-invasive indicator of short term changes in the portal blood flow, while liver function tests were determined as an indicator of long term changes in liver functions. Results: A total of 38 patients completed the whole month fasting and two patients discontinued fasting due to variceal bleeding. The complicated patients were 7. CI showed a statistically significant increase from fasting to postprandial status (P<0.001), with statistically significant increases from fasting to postprandial status in Child class A (P<0.001), and B (P<0.001). We did not find a statistical significance between patients with complications and those without complications (P=0.6). There was a statistically significant rise in the serum bilirubin after Ramadan. Deterioration noticed as advanced Child classes, development of lower limb edema, increasing ascites, increasing jaundice and overt encephalopathy. Conclusion: Cirrhotic patients showed significant short-term changes in the portal blood flow. However, these changes are not linked to complications or deterioration of liver functions and accommodated especially in patients with Child class A and B. Child class C patients should not fast. PMID:27458510
Cognitive predictors of balance in Parkinson's disease.
Fernandes, Ângela; Mendes, Andreia; Rocha, Nuno; Tavares, João Manuel R S
2016-06-01
Postural instability is one of the most incapacitating symptoms of Parkinson's disease (PD) and appears to be related to cognitive deficits. This study aims to determine the cognitive factors that can predict deficits in static and dynamic balance in individuals with PD. A sociodemographic questionnaire characterized 52 individuals with PD for this work. The Trail Making Test, Rule Shift Cards Test, and Digit Span Test assessed the executive functions. The static balance was assessed using a plantar pressure platform, and dynamic balance was based on the Timed Up and Go Test. The results were statistically analysed using SPSS Statistics software through linear regression analysis. The results show that a statistically significant model based on cognitive outcomes was able to explain the variance of motor variables. Also, the explanatory value of the model tended to increase with the addition of individual and clinical variables, although the resulting model was not statistically significant The model explained 25-29% of the variability of the Timed Up and Go Test, while for the anteroposterior displacement it was 23-34%, and for the mediolateral displacement it was 24-39%. From the findings, we conclude that the cognitive performance, especially the executive functions, is a predictor of balance deficit in individuals with PD.
ERIC Educational Resources Information Center
Finnie, Ross; Frenette, Marc
2003-01-01
Analysis of earnings differences by major field of study of three cohorts of graduates (1982, 1986, 1990) with bachelors' degrees from Canadian postsecondary institutions. Finds that earnings differences are large and statistically significant. The patterns are relatively consistent for the three cohorts and for male and female graduates, 2 and 5…
ERIC Educational Resources Information Center
Sandler, Andrew B.
Statistical significance is misused in educational and psychological research when it is applied as a method to establish the reliability of research results. Other techniques have been developed which can be correctly utilized to establish the generalizability of findings. Methods that do provide such estimates are known as invariance or…
Addendum to the Evaluation of the Expository Reading and Writing Course
ERIC Educational Resources Information Center
Fong, Anthony B.; Finkelstein, Neal D.
2016-01-01
In 2015, Fong, Finkelstein, Jaeger, Diaz, and Broek reported the findings from an independent evaluation of the Expository Reading and Writing Course (ERWC). The evaluation found positive and statistically significant effects of the ERWC on student achievement. Due to some concerns that the previously reported results in Fong et al. (2015) did not…
Protocol Analysis of Man-Computer Languages: Design and Preliminary Findings
1975-07-01
describes a statistical moael o propot of the exercise. It is one particular model used for analysis of variance which allows us to test the significance of... Body : Congressman Blake will be visiting Camp Smith to confer with J6, J612, and Col. Smith with regard to operation of the pilot project on
ERIC Educational Resources Information Center
Nguyen, Dat-Dao; Zhang, Yue
2011-01-01
This study uses the Learning-Style Inventory--LSI (Smith & Kolb, 1985) to explore to what extent student attitudes toward learning process and outcome of online instruction and Distance Learning are affected by their cognitive styles and learning behaviors. It finds that there are not much statistically significant differences in perceptions…
Online vs. On-Campus: An Analysis of Course Prices of U.S. Educational Institutions
ERIC Educational Resources Information Center
Wang, Shouhong
2015-01-01
Pricing online courses is an important issue for managing online education. This research note reports a statistical analysis of price differences between online courses and on-campus courses at 103 US educational institutions based on the data available on the Internet. The finding indicates that educational institutions set significantly lower…
Do Students' College Major Choices Respond to Changes in Wages? CEDR Working Paper. WP #2014-6
ERIC Educational Resources Information Center
Long, Mark C.; Goldhaber, Dan; Huntington-Klein, Nick
2014-01-01
We find statistically significant relationships between changes in wages by occupation and subsequent changes in college majors completed in associated fields. College majors (defined at a detailed level) are most strongly related to wages observed three years earlier, when students were college freshmen. The responses to wages vary depending on…
?Cuan buenas son nuestras viviendas?: Los hispanos [How Good Is Our Housing? Hispanics].
ERIC Educational Resources Information Center
Yezer, Anthony; Limmer, Ruth
This report provides statistical information regarding the quality and cost of housing occupied by Hispanic Americans throughout the United States. Some of the findings include: (1) Hispanos occupy older and worse dwellings than the general U.S. population, with a significant number of dwellings lacking heat and adequate electricity and plumbing…
Objective: Explain why epidemiologic studies find a statistically significant relationship between ambient concentrations of PM and health effects even though only a near-zero correlation is found between ambient concentrations of PM and personal exposures to PM. Method: Consider...
ERIC Educational Resources Information Center
Clemens, Nathan H.; Hagan-Burke, Shanna; Luo, Wen; Cerda, Carissa; Blakely, Alane; Frosch, Jennifer; Gamez-Patience, Brenda; Jones, Meredith
2015-01-01
This study examined the predictive validity of a computer-adaptive assessment for measuring kindergarten reading skills using the STAR Early Literacy (SEL) test. The findings showed that the results of SEL assessments administered during the fall, winter, and spring of kindergarten were moderate and statistically significant predictors of year-end…
Play Therapy in Elementary Schools: A Best Practice for Improving Academic Achievement
ERIC Educational Resources Information Center
Blanco, Pedro J.; Ray, Dee C.
2011-01-01
This pilot study of 1st graders who are academically at risk examined the effectiveness of child-centered play therapy (CCPT). The experimental group received biweekly, 30-minute play therapy sessions for 8 weeks. Findings indicated that these 1st graders participating in CCPT (n = 21) demonstrated a statistically significant increase on the Early…
Correlations among Jamaican 12th-Graders' Five Variables and Performance in Genetics
ERIC Educational Resources Information Center
Bloomfield, Deen-Paul; Soyibo, Kola
2008-01-01
This study was aimed at finding out if the level of performance of selected Jamaican Grade 12 students on an achievement test on the concept of genetics was satisfactory; if there were statistically significant differences in their performance on the concept linked to their gender, self-esteem, cognitive abilities in biology, school-type and…
Class Size and Student Evaluations in Sweden
ERIC Educational Resources Information Center
Westerlund, Joakim
2008-01-01
This paper examines the effect of class size on student evaluations of the quality of an introductory mathematics course at Lund University in Sweden. In contrast to much other studies, we find a large negative, and statistically significant, effect of class size on the quality of the course. This result appears to be quite robust, as almost all…
Duerden, E G; Foong, J; Chau, V; Branson, H; Poskitt, K J; Grunau, R E; Synnes, A; Zwicker, J G; Miller, S P
2015-08-01
Adverse neurodevelopmental outcome is common in children born preterm. Early sensitive predictors of neurodevelopmental outcome such as MR imaging are needed. Tract-based spatial statistics, a diffusion MR imaging analysis method, performed at term-equivalent age (40 weeks) is a promising predictor of neurodevelopmental outcomes in children born very preterm. We sought to determine the association of tract-based spatial statistics findings before term-equivalent age with neurodevelopmental outcome at 18-months corrected age. Of 180 neonates (born at 24-32-weeks' gestation) enrolled, 153 had DTI acquired early at 32 weeks' postmenstrual age and 105 had DTI acquired later at 39.6 weeks' postmenstrual age. Voxelwise statistics were calculated by performing tract-based spatial statistics on DTI that was aligned to age-appropriate templates. At 18-month corrected age, 166 neonates underwent neurodevelopmental assessment by using the Bayley Scales of Infant Development, 3rd ed, and the Peabody Developmental Motor Scales, 2nd ed. Tract-based spatial statistics analysis applied to early-acquired scans (postmenstrual age of 30-33 weeks) indicated a limited significant positive association between motor skills and axial diffusivity and radial diffusivity values in the corpus callosum, internal and external/extreme capsules, and midbrain (P < .05, corrected). In contrast, for term scans (postmenstrual age of 37-41 weeks), tract-based spatial statistics analysis showed a significant relationship between both motor and cognitive scores with fractional anisotropy in the corpus callosum and corticospinal tracts (P < .05, corrected). Tract-based spatial statistics in a limited subset of neonates (n = 22) scanned at <30 weeks did not significantly predict neurodevelopmental outcomes. The strength of the association between fractional anisotropy values and neurodevelopmental outcome scores increased from early-to-late-acquired scans in preterm-born neonates, consistent with brain dysmaturation in this population. © 2015 by American Journal of Neuroradiology.
Tympanometric Findings among Children with Adenoid Hypertrophy in Port Harcourt, Nigeria
Nwosu, Chibuike; Uju Ibekwe, Mathilda
2016-01-01
Introduction. Adenoid hypertrophy (AH) is a common childhood disorder. Adenoid plays a significant role in the pathogenesis of otitis media with effusion (OME). The aim of this study is to critically appraise the tympanometric finding among children with adenoid hypertrophy in Port Harcourt, Nigeria. Methodology. A Prospective, controlled study carried out among newly diagnosed cases of adenoid hypertrophy at the ENT clinic of the UPTH, between November 2014 and June 2015. Tympanometry was done on each child and each ear was considerably studied as a single entity. Types B and C tympanograms were used as indicators of OME. Data was collected and analyzed using SPSS version 20. Results. Sixty-eight cases of adenoid hypertrophy were seen within the study period and 136 ears were studied. Forty (29.4%) ears had type B tympanogram, while 36 (26.5%) ears had type C. The incidence of OME was 55.9%; there were 12 (17.6%) unilateral OME, while bilateral OME was 32 (47.1%). Grade 3 AH was prevalent and was statistically significant with the OME. Conclusion. This study had shown adenoidal hypertrophy as a significant risk factor for OME in children. There was more bilateral OME than unilateral. The more severe grade of AH was more prevalent and it was shown to be statistically significant with OME, thus being a significant risk factor for OME in children. This establishes the need for prompt hearing evaluation and management. PMID:27563311
Spatial Autocorrelation of Cancer Incidence in Saudi Arabia
Al-Ahmadi, Khalid; Al-Zahrani, Ali
2013-01-01
Little is known about the geographic distribution of common cancers in Saudi Arabia. We explored the spatial incidence patterns of common cancers in Saudi Arabia using spatial autocorrelation analyses, employing the global Moran’s I and Anselin’s local Moran’s I statistics to detect nonrandom incidence patterns. Global ordinary least squares (OLS) regression and local geographically-weighted regression (GWR) were applied to examine the spatial correlation of cancer incidences at the city level. Population-based records of cancers diagnosed between 1998 and 2004 were used. Male lung cancer and female breast cancer exhibited positive statistically significant global Moran’s I index values, indicating a tendency toward clustering. The Anselin’s local Moran’s I analyses revealed small significant clusters of lung cancer, prostate cancer and Hodgkin’s disease among males in the Eastern region and significant clusters of thyroid cancers in females in the Eastern and Riyadh regions. Additionally, both regression methods found significant associations among various cancers. For example, OLS and GWR revealed significant spatial associations among NHL, leukemia and Hodgkin’s disease (r² = 0.49–0.67 using OLS and r² = 0.52–0.68 using GWR) and between breast and prostate cancer (r² = 0.53 OLS and 0.57 GWR) in Saudi Arabian cities. These findings may help to generate etiologic hypotheses of cancer causation and identify spatial anomalies in cancer incidence in Saudi Arabia. Our findings should stimulate further research on the possible causes underlying these clusters and associations. PMID:24351742
Vartanian, Oshin; Wertz, Christopher J; Flores, Ranee A; Beatty, Erin L; Smith, Ingrid; Blackler, Kristen; Lam, Quan; Jung, Rex E
2018-04-15
Openness/Intellect (i.e., openness to experience) is the Big Five personality factor most consistently associated with individual differences in creativity. Recent psychometric evidence has demonstrated that this factor consists of two distinct aspects-Intellect and Openness. Whereas Intellect reflects perceived intelligence and intellectual engagement, Openness reflects engagement with fantasy, perception, and aesthetics. We investigated the extent to which Openness and Intellect are associated with variations in brain structure as measured by cortical thickness, area, and volume (N = 185). Our results demonstrated that Openness was correlated inversely with cortical thickness and volume in left middle frontal gyrus (BA 6), middle temporal gyrus (MTG, BA 21), and superior temporal gyrus (BA 41), and exclusively with cortical thickness in left inferior parietal lobule (BA 40), right inferior frontal gyrus (IFG, BA 45), and MTG (BA 37). When age and sex were statistically controlled for, the inverse correlations between Openness and cortical thickness remained statistically significant for all regions except left MTG, whereas the correlations involving cortical volume remained statistically significant only for left middle frontal gyrus. There was no statistically significant correlation between Openness and cortical area, and no statistically significant correlation between Intellect and cortical thickness, area, or volume. Our results demonstrate that individual differences in Openness are correlated with variation in brain structure-particularly as indexed by cortical thickness. Given the involvement of the above regions in processes related to memory and cognitive control, we discuss the implications of our findings for the possible contribution of personality to creative cognition. © 2018 Her Majesty the Queen in Right of Canada 2018. Reproduced with permission of the Minister of Health, Canada. Human Brain Mapping.
Hot spot detection and spatio-temporal dispersion of dengue fever in Hanoi, Vietnam
Toan, Do Thi Thanh; Hu, Wenbiao; Thai, Pham Quang; Hoat, Luu Ngoc; Wright, Pamela; Martens, Pim
2013-01-01
Introduction Dengue fever (DF) in Vietnam remains a serious emerging arboviral disease, which generates significant concerns among international health authorities. Incidence rates of DF have increased significantly during the last few years in many provinces and cities, especially Hanoi. The purpose of this study was to detect DF hot spots and identify the disease dynamics dispersion of DF over the period between 2004 and 2009 in Hanoi, Vietnam. Methods Daily data on DF cases and population data for each postcode area of Hanoi between January 1998 and December 2009 were obtained from the Hanoi Center for Preventive Health and the General Statistic Office of Vietnam. Moran's I statistic was used to assess the spatial autocorrelation of reported DF. Spatial scan statistics and logistic regression were used to identify space–time clusters and dispersion of DF. Results The study revealed a clear trend of geographic expansion of DF transmission in Hanoi through the study periods (OR 1.17, 95% CI 1.02–1.34). The spatial scan statistics showed that 6/14 (42.9%) districts in Hanoi had significant cluster patterns, which lasted 29 days and were limited to a radius of 1,000 m. The study also demonstrated that most DF cases occurred between June and November, during which the rainfall and temperatures are highest. Conclusions There is evidence for the existence of statistically significant clusters of DF in Hanoi, and that the geographical distribution of DF has expanded over recent years. This finding provides a foundation for further investigation into the social and environmental factors responsible for changing disease patterns, and provides data to inform program planning for DF control. PMID:23364076
Hot spot detection and spatio-temporal dispersion of dengue fever in Hanoi, Vietnam.
Toan, Do Thi Thanh; Hu, Wenbiao; Quang Thai, Pham; Hoat, Luu Ngoc; Wright, Pamela; Martens, Pim
2013-01-24
Dengue fever (DF) in Vietnam remains a serious emerging arboviral disease, which generates significant concerns among international health authorities. Incidence rates of DF have increased significantly during the last few years in many provinces and cities, especially Hanoi. The purpose of this study was to detect DF hot spots and identify the disease dynamics dispersion of DF over the period between 2004 and 2009 in Hanoi, Vietnam. Daily data on DF cases and population data for each postcode area of Hanoi between January 1998 and December 2009 were obtained from the Hanoi Center for Preventive Health and the General Statistic Office of Vietnam. Moran's I statistic was used to assess the spatial autocorrelation of reported DF. Spatial scan statistics and logistic regression were used to identify space-time clusters and dispersion of DF. The study revealed a clear trend of geographic expansion of DF transmission in Hanoi through the study periods (OR 1.17, 95% CI 1.02-1.34). The spatial scan statistics showed that 6/14 (42.9%) districts in Hanoi had significant cluster patterns, which lasted 29 days and were limited to a radius of 1,000 m. The study also demonstrated that most DF cases occurred between June and November, during which the rainfall and temperatures are highest. There is evidence for the existence of statistically significant clusters of DF in Hanoi, and that the geographical distribution of DF has expanded over recent years. This finding provides a foundation for further investigation into the social and environmental factors responsible for changing disease patterns, and provides data to inform program planning for DF control.
Universal Recurrence Time Statistics of Characteristic Earthquakes
NASA Astrophysics Data System (ADS)
Goltz, C.; Turcotte, D. L.; Abaimov, S.; Nadeau, R. M.
2006-12-01
Characteristic earthquakes are defined to occur quasi-periodically on major faults. Do recurrence time statistics of such earthquakes follow a particular statistical distribution? If so, which one? The answer is fundamental and has important implications for hazard assessment. The problem cannot be solved by comparing the goodness of statistical fits as the available sequences are too short. The Parkfield sequence of M ≍ 6 earthquakes, one of the most extensive reliable data sets available, has grown to merely seven events with the last earthquake in 2004, for example. Recently, however, advances in seismological monitoring and improved processing methods have unveiled so-called micro-repeaters, micro-earthquakes which recur exactly in the same location on a fault. It seems plausible to regard these earthquakes as a miniature version of the classic characteristic earthquakes. Micro-repeaters are much more frequent than major earthquakes, leading to longer sequences for analysis. Due to their recent discovery, however, available sequences contain less than 20 events at present. In this paper we present results for the analysis of recurrence times for several micro-repeater sequences from Parkfield and adjacent regions. To improve the statistical significance of our findings, we combine several sequences into one by rescaling the individual sets by their respective mean recurrence intervals and Weibull exponents. This novel approach of rescaled combination yields the most extensive data set possible. We find that the resulting statistics can be fitted well by an exponential distribution, confirming the universal applicability of the Weibull distribution to characteristic earthquakes. A similar result is obtained from rescaled combination, however, with regard to the lognormal distribution.
NASA Astrophysics Data System (ADS)
Doerr, Timothy; Alves, Gelio; Yu, Yi-Kuo
2006-03-01
Typical combinatorial optimizations are NP-hard; however, for a particular class of cost functions the corresponding combinatorial optimizations can be solved in polynomial time. This suggests a way to efficiently find approximate solutions - - find a transformation that makes the cost function as similar as possible to that of the solvable class. After keeping many high-ranking solutions using the approximate cost function, one may then re-assess these solutions with the full cost function to find the best approximate solution. Under this approach, it is important to be able to assess the quality of the solutions obtained, e.g., by finding the true ranking of kth best approximate solution when all possible solutions are considered exhaustively. To tackle this statistical issue, we provide a systematic method starting with a scaling function generated from the fininte number of high- ranking solutions followed by a convergent iterative mapping. This method, useful in a variant of the directed paths in random media problem proposed here, can also provide a statistical significance assessment for one of the most important proteomic tasks - - peptide sequencing using tandem mass spectrometry data.
Al-Anezi, Saud A
2014-01-01
Background: To compare changes in the amount and distribution of dental plaque associated with placement of elastomeric modules over a self-ligating bracket during orthodontic treatment and to relate these changes to the periodontal inflammation. Materials and Methods: A cross-arch randomization trial was carried out at Bristol Dental School, United Kingdom. Clinical measurements of periodontal inflammation and plaque accumulation and microbiological test were done on 24 patients aged 11-14 years [Mean (SD) age = 12.6 (1.01) years] wearing fixed appliances (Damon 2 brackets, Ormco, Orange, CA, USA) at the start and 3 months into fixed orthodontic treatment. Results: In the first 3 months of treatment there was no statistically significant difference in bleeding on probing between incisors with and without elastomeric modules (P = 0.125 and 0.508, respectively). The difference in plaque accumulation was not statistically significant (P = 0.78). The difference in probing depths between the incisors was not statistically significant (P = 0.84). The microbiological analysis showed no difference. Conclusions: Based on this preliminary 3 months study, elastomeric modules were not significantly associated with any increased risk during treatment when compared to self-ligating brackets. The longer term studies are needed to further confirm the findings of the present study. PMID:24987657
The effect of teaching medical ethics on medical students' moral reasoning.
Self, D J; Wolinsky, F D; Baldwin, D C
1989-12-01
A study assessed the effect of incorporating medical ethics into the medical curriculum and the relative effects of two methods of implementing that curriculum, namely, lecture and case-study discussions. Results indicate a statistically significant increase (p less than or equal to .0001) in the level of moral reasoning of students exposed to the medical ethics course, regardless of format. Moreover, the unadjusted posttest scores indicated that the case-study method was significantly (p less than or equal to .03) more effective than the lecture method in increasing students' level of moral reasoning. When adjustment were made for the pretest scores, however, this difference was not statistically significant (p less than or equal to .18). Regression analysis by linear panel techniques revealed that age, gender, undergraduate grade-point average, and scores on the Medical College Admission Test were not related to the changes in moral-reasoning scores. All of the variance that could be explained was due to the students' being in one of the two experimental groups. In comparison with the control group, the change associated with each experimental format was statistically significant (lecture, p less than or equal to .004; case study, p less than or equal to .0001). Various explanations for these findings and their implications are given.
Sex differences in thickness, and folding developments throughout the cortex.
Mutlu, A Kadir; Schneider, Maude; Debbané, Martin; Badoud, Deborah; Eliez, Stephan; Schaer, Marie
2013-11-15
While significant differences in male and female brain structures have commonly been reported, only a few studies have focused on the sex differences in the way the cortex matures over time. Here, we investigated cortical thickness maturation between the age of 6 to 30 years, using 209 longitudinally-acquired brain MRI scans. Significant sex differences in the trajectories of cortical thickness change with age were evidenced using non-linear mixed effects models. Similar statistical analyses were computed to quantify the differences between cortical gyrification changes with age in males and females. During adolescence, we observed a statistically significant higher rate of cortical thinning in females compared to males in the right temporal regions, the left temporoparietal junction and the left orbitofrontal cortex. This finding is interpreted as a faster maturation of the social brain areas in females. Concomitantly, statistically significant sex differences in cortical folding changes with age were observed only in one cluster of the right prefrontal regions, suggesting that the mechanisms underlying cortical thickness and gyrification changes with age are quite distinct. Sexual dimorphism in the developmental course of the cortical maturation may be associated with the different age of onset and clinical presentation of many psychiatric disorders between males and females. Copyright © 2013 Elsevier Inc. All rights reserved.
Chang, Wei-Lung; Liu, Hsiang-Te; Lin, Tai-An; Wen, Yung-Sung
2008-01-01
The purpose of this research was to study the relationship between family communication structure, vanity trait, and related consumption behavior. The study used an empirical method with adolescent students from the northern part of Taiwan as the subjects. Multiple statistical methods and the SEM model were used for testing the hypotheses. The major findings were: (1) Socio-orientation has a significant effect on how physical appearance is viewed, and concept-orientation has a significant positive effect on achievement vanity. (2) how physical appearance is viewed has a significant positive effect on all dimensions of materialism, concerns about clothing, and use of cosmetics. (3) Achievement vanity has a significant positive relationship with price-based prestige sensitivity and concerns regarding clothing. The findings have implications for marketing theory as well as for practical applications in marketing.
Sensorimotor abilities predict on-field performance in professional baseball.
Burris, Kyle; Vittetoe, Kelly; Ramger, Benjamin; Suresh, Sunith; Tokdar, Surya T; Reiter, Jerome P; Appelbaum, L Gregory
2018-01-08
Baseball players must be able to see and react in an instant, yet it is hotly debated whether superior performance is associated with superior sensorimotor abilities. In this study, we compare sensorimotor abilities, measured through 8 psychomotor tasks comprising the Nike Sensory Station assessment battery, and game statistics in a sample of 252 professional baseball players to evaluate the links between sensorimotor skills and on-field performance. For this purpose, we develop a series of Bayesian hierarchical latent variable models enabling us to compare statistics across professional baseball leagues. Within this framework, we find that sensorimotor abilities are significant predictors of on-base percentage, walk rate and strikeout rate, accounting for age, position, and league. We find no such relationship for either slugging percentage or fielder-independent pitching. The pattern of results suggests performance contributions from both visual-sensory and visual-motor abilities and indicates that sensorimotor screenings may be useful for player scouting.
Probing the statistical properties of CMB B-mode polarization through Minkowski functionals
NASA Astrophysics Data System (ADS)
Santos, Larissa; Wang, Kai; Zhao, Wen
2016-07-01
The detection of the magnetic type B-mode polarization is the main goal of future cosmic microwave background (CMB) experiments. In the standard model, the B-mode map is a strong non-gaussian field due to the CMB lensing component. Besides the two-point correlation function, the other statistics are also very important to dig the information of the polarization map. In this paper, we employ the Minkowski functionals to study the morphological properties of the lensed B-mode maps. We find that the deviations from Gaussianity are very significant for both full and partial-sky surveys. As an application of the analysis, we investigate the morphological imprints of the foreground residuals in the B-mode map. We find that even for very tiny foreground residuals, the effects on the map can be detected by the Minkowski functional analysis. Therefore, it provides a complementary way to investigate the foreground contaminations in the CMB studies.
Rock, Melanie
2003-06-01
Anthropologists have begun to publish ethnographic accounts of policy-making, but few have studied medical or health matters, despite broad acceptance in anthropology that "biopower" permeates contemporary societies. This article presents some findings from an ethnographic study of how diabetes gained recognition as a pressing public health problem in Canada. It underlines the importance of statistics for constituting power within and across nation states. Statistics imbricate people and things distributed across vast distances, but they still need to be generated and invoked by individuals to engender effects--as illustrated in this article by the contributions of researchers, aboriginal leaders, and an American actress, Mary Tyler Moore--in this case, the development of Canadian government policies justified in the name of averting and controlling diabetes. To make sense of these findings, subtle differences between two concepts coined by Michel Foucault, "biopower" and "governmentality," seem significant.
Owen, Stewart F; Huggett, Duane B; Hutchinson, Thomas H; Hetheridge, Malcolm J; McCormack, Paul; Kinter, Lewis B; Ericson, Jon F; Constantine, Lisa A; Sumpter, John P
2010-12-01
Two studies to examine the effect of waterborne clofibric acid (CA) on growth-rate and condition of rainbow trout were conducted using accepted regulatory tests (Organisation for Economic Co-operation and Development [OECD] 215). The first study (in 2005) showed significant reductions after 21 d of exposure (21-d growth lowest-observed-effect concentration [LOEC] = 0.1 µg/L, 21-d condition LOEC = 0.1 µg/L) that continued to 28 d. Growth rate was reduced by approximately 50% (from 5.27 to 2.67% per day), while the condition of the fish reduced in a concentration-dependant manner. Additionally, in a concentration-dependent manner, significant changes in relative liver size were observed, such that increasing concentrations of CA resulted in smaller livers after 28-d exposure. A no-observed-effect concentration (NOEC) was not achieved in the 2005 study. An expanded second study (in 2006) that included a robust bridge to the 2005 study, with four replicate tanks of eight individual fish per concentration, did not repeat the 2005 findings. In the 2006 study, no significant effect on growth rate, condition, or liver biometry was observed after 21 or 28 d (28-d growth NOEC = 10 µg/L, 28-d condition NOEC = 10 µg/L), contrary to the 2005 findings. We do not dismiss either of these findings and suggest both are relevant and stand for comparison. However, the larger 2006 study carries more statistical power and multiple-tank replication, so probably produced the more robust findings. Despite sufficient statistical power in each study, interpretation of these and similar studies should be conducted with caution, because much significance is placed on the role of limited numbers of individual and tank replicates and the influence of control animals. Copyright © 2010 SETAC.
2012-01-01
Background Oestrogen and progestogen have the potential to influence gastro-intestinal motility; both are key components of hormone replacement therapy (HRT). Results of observational studies in women taking HRT rely on self-reporting of gastro-oesophageal symptoms and the aetiology of gastro-oesophageal reflux disease (GORD) remains unclear. This study investigated the association between HRT and GORD in menopausal women using validated general practice records. Methods 51,182 menopausal women were identified using the UK General Practice Research Database between 1995–2004. Of these, 8,831 were matched with and without hormone use. Odds ratios (ORs) were calculated for GORD and proton-pump inhibitor (PPI) use in hormone and non-hormone users, adjusting for age, co-morbidities, and co-pharmacy. Results In unadjusted analysis, all forms of hormone use (oestrogen-only, tibolone, combined HRT and progestogen) were statistically significantly associated with GORD. In adjusted models, this association remained statistically significant for oestrogen-only treatment (OR 1.49; 1.18–1.89). Unadjusted analysis showed a statistically significant association between PPI use and oestrogen-only and combined HRT treatment. When adjusted for covariates, oestrogen-only treatment was significant (OR 1.34; 95% CI 1.03–1.74). Findings from the adjusted model demonstrated the greater use of PPI by progestogen users (OR 1.50; 1.01–2.22). Conclusions This first large cohort study of the association between GORD and HRT found a statistically significant association between oestrogen-only hormone and GORD and PPI use. This should be further investigated using prospective follow-up to validate the strength of association and describe its clinical significance. PMID:22642788
Rahbar, Mohammad H.; Samms-Vaughan, Maureen; Pitcher, Meagan R.; Bressler, Jan; Hessabi, Manouchehr; Loveland, Katherine A.; Christian, MacKinsey A.; Grove, Megan L.; Shakespeare-Pellington, Sydonnie; Beecher, Compton; McLaughlin, Wayne; Boerwinkle, Eric
2016-01-01
Aluminum is a neurotoxic metal with known health effects in animals and humans. Glutathione-S-transferase (GST) genes and enzymes play a major role in detoxification of several heavy metals. Besides a direct relationship with oxidative stress; aluminum decreases GST enzyme activities. Using data from 116 Jamaican children; age 2–8 years; with Autism Spectrum Disorder (ASD) and 116 sex- and age-matched typically developing (TD) children; we investigated the association of polymorphisms in three GST genes (GSTP1; GSTM1; and GSTT1) with mean blood aluminum concentrations in children with and without ASD. Using log-transformed blood aluminum concentration as the dependent variable in a linear regression model; we assessed the additive and interactive effects of ASD status and polymorphisms in the three aforementioned GST genes in relation to blood aluminum concentrations. Although none of the additive effects were statistically significant (all p > 0.16); we observed a marginally significant interaction between GSTP1 Ile105Val (rs1695) and ASD status (p = 0.07); even after controlling for parental education level and consumption of avocado; root vegetables; and tuna (canned fish). Our findings indicate a significantly lower (p < 0.03) adjusted geometric mean blood aluminum concentration for TD children who had the Val/Val genotype (14.57 µg/L); compared with those with Ile/Ile or Ile/Val genotypes who had an adjusted geometric mean of 23.75 µg/L. However; this difference was not statistically significant among the ASD cases (p = 0.76). Our findings indicate that ASD status may be a potential effect modifier when assessing the association between GSTP1 rs1695 and blood aluminum concentrations among Jamaican children. These findings require replication in other populations. PMID:27834815
Evidence-based practice knowledge, attitudes, and practice of online graduate nursing students.
Rojjanasrirat, Wilaiporn; Rice, Jan
2017-06-01
This study aimed to evaluate changes in evidence-based practice (EBP) knowledge, attitudes, and practice of nursing students before and after completing an online, graduate level, introductory research/EBP course. A prospective one-group pretest-posttest design. A private university in the Midwestern, USA. Sixty-three online nurse practitioner students in Master's program. A convenient sample of online graduate nursing students who enrolled in the research/EBP course was invited to participate in the study. Study outcomes were measured using the Evidence-Based Practice Questionnaire (EBPQ) before and after completing the course. Descriptive statistics and paired-Samples t-test was used to assess the mean differences between pre-and post-test scores. Overall, students' post-test EBP scores were significantly improved over pre-test scores, t(63)=-9.034, p<0.001). Statistically significant differences were found for practice of EBP mean scores t(63)=-12.78, p=0.001). No significant differences were found between pre and post-tests on knowledge and attitudes toward EBP scores. Most frequently cited barriers to EBP were lack of understanding of statistics, interpretation of findings, lack of time, and lack of library resources. Copyright © 2017 Elsevier Ltd. All rights reserved.
Assessment of statistical significance and clinical relevance.
Kieser, Meinhard; Friede, Tim; Gondan, Matthias
2013-05-10
In drug development, it is well accepted that a successful study will demonstrate not only a statistically significant result but also a clinically relevant effect size. Whereas standard hypothesis tests are used to demonstrate the former, it is less clear how the latter should be established. In the first part of this paper, we consider the responder analysis approach and study the performance of locally optimal rank tests when the outcome distribution is a mixture of responder and non-responder distributions. We find that these tests are quite sensitive to their planning assumptions and have therefore not really any advantage over standard tests such as the t-test and the Wilcoxon-Mann-Whitney test, which perform overall well and can be recommended for applications. In the second part, we present a new approach to the assessment of clinical relevance based on the so-called relative effect (or probabilistic index) and derive appropriate sample size formulae for the design of studies aiming at demonstrating both a statistically significant and clinically relevant effect. Referring to recent studies in multiple sclerosis, we discuss potential issues in the application of this approach. Copyright © 2012 John Wiley & Sons, Ltd.
Erfanian, Parham; Tenzif, Siamak; Guerriero, Rocco C
2004-01-01
Objective To determine the effects of a semi-customized experimental cervical pillow on symptomatic adults with chronic neck pain (with and without headache) during a four week study. Design A randomized controlled trial. Sample size Thirty-six adults were recruited for the trial, and randomly assigned to experimental or non-experimental groups of 17 and 19 participants respectively. Subjects Adults with chronic biomechanical neck pain who were recruited from the Canadian Memorial Chiropractic College (CMCC) Walk-in Clinic. Outcome measures Subjective findings were assessed using a mail-in self-report daily pain diary, and the CMCC Neck Disability Index (NDI). Statistical analysis Using repeated measure analysis of variance weekly NDI scores, average weekly AM and PM pain scores between the experimental and non-experimental groups were compared throughout the study. Results The experimental group had statistically significant lower NDI scores (p < 0.05) than the non-experimental group. The average weekly AM scores were lower and statistically significant (p < 0.05) in the experimental group. The PM scores in the experimental group were lower but not statistically significant than the other group. Conclusions The study results show that compared to conventional pillows, this experimental semi-customized cervical pillow was effective in reducing low-level neck pain intensity, especially in the morning following its use in a 4 week long study. PMID:17549216
Pingault, Jean Baptiste; Côté, Sylvana M; Petitclerc, Amélie; Vitaro, Frank; Tremblay, Richard E
2015-01-01
Parental educational expectations have been associated with children's educational attainment in a number of long-term longitudinal studies, but whether this relationship is causal has long been debated. The aims of this prospective study were twofold: 1) test whether low maternal educational expectations contributed to failure to graduate from high school; and 2) compare the results obtained using different strategies for accounting for confounding variables (i.e. multivariate regression and propensity score matching). The study sample included 1,279 participants from the Quebec Longitudinal Study of Kindergarten Children. Maternal educational expectations were assessed when the participants were aged 12 years. High school graduation—measuring educational attainment—was determined through the Quebec Ministry of Education when the participants were aged 22-23 years. Findings show that when using the most common statistical approach (i.e. multivariate regressions to adjust for a restricted set of potential confounders) the contribution of low maternal educational expectations to failure to graduate from high school was statistically significant. However, when using propensity score matching, the contribution of maternal expectations was reduced and remained statistically significant only for males. The results of this study are consistent with the possibility that the contribution of parental expectations to educational attainment is overestimated in the available literature. This may be explained by the use of a restricted range of potential confounding variables as well as the dearth of studies using appropriate statistical techniques and study designs in order to minimize confounding. Each of these techniques and designs, including propensity score matching, has its strengths and limitations: A more comprehensive understanding of the causal role of parental expectations will stem from a convergence of findings from studies using different techniques and designs.
Revised standards for statistical evidence.
Johnson, Valen E
2013-11-26
Recent advances in Bayesian hypothesis testing have led to the development of uniformly most powerful Bayesian tests, which represent an objective, default class of Bayesian hypothesis tests that have the same rejection regions as classical significance tests. Based on the correspondence between these two classes of tests, it is possible to equate the size of classical hypothesis tests with evidence thresholds in Bayesian tests, and to equate P values with Bayes factors. An examination of these connections suggest that recent concerns over the lack of reproducibility of scientific studies can be attributed largely to the conduct of significance tests at unjustifiably high levels of significance. To correct this problem, evidence thresholds required for the declaration of a significant finding should be increased to 25-50:1, and to 100-200:1 for the declaration of a highly significant finding. In terms of classical hypothesis tests, these evidence standards mandate the conduct of tests at the 0.005 or 0.001 level of significance.
Finding idle machines in a workstation-based distributed system
NASA Technical Reports Server (NTRS)
Theimer, Marvin M.; Lantz, Keith A.
1989-01-01
The authors describe the design and performance of scheduling facilities for finding idle hosts in a workstation-based distributed system. They focus on the tradeoffs between centralized and decentralized architectures with respect to scalability, fault tolerance, and simplicity of design, as well as several implementation issues of interest when multicast communication is used. They conclude that the principal tradeoff between the two approaches is that a centralized architecture can be scaled to a significantly greater degree and can more easily monitor global system statistics, whereas a decentralized architecture is simpler to implement.
Memory and Trend of Precipitation in China during 1966-2013
NASA Astrophysics Data System (ADS)
Du, M.; Sun, F.; Liu, W.
2017-12-01
As climate change has had a significant impact on water cycle, the characteristic and variation of precipitation under climate change turned into a hotspot in hydrology. This study aims to analyze the trend and memory (both short-term and long-term) of precipitation in China. To do that, we apply statistical tests (including Mann-Kendall test, Ljung-Box test and Hurst exponent) to annual precipitation (P), frequency of rainy day (λ) and mean daily rainfall in days when precipitation occurs (α) in China (1966-2013). We also use a resampling approach to determine the field significance. From there, we evaluate the spatial distribution and percentages of stations with significant memory or trend. We find that the percentages of significant downtrends for λ and significant uptrends for α are significantly larger than the critical values at 95% field significance level, probably caused by the global warming. From these results, we conclude that extra care is necessary when significant results are obtained using statistical tests. This is because the null hypothesis could be rejected by chance and this situation is more likely to occur if spatial correlation is ignored according to the results of the resampling approach.
Cross-correlations between crude oil and agricultural commodity markets
NASA Astrophysics Data System (ADS)
Liu, Li
2014-02-01
In this paper, we investigate cross-correlations between crude oil and agricultural commodity markets. Based on a popular statistical test proposed by Podobnik et al. (2009), we find that the linear return cross-correlations are significant at larger lag lengths and the volatility cross-correlations are highly significant at all of the lag lengths under consideration. Using a detrended cross-correlation analysis (DCCA), we find that the return cross-correlations are persistent for corn and soybean and anti-persistent for oat and soybean. The volatility cross-correlations are strongly persistent. Using a nonlinear cross-correlation measure, our results show that cross-correlations are relatively weak but they are significant for smaller time scales. For larger time scales, the cross-correlations are not significant. The reason may be that information transmission from crude oil market to agriculture markets can complete within a certain period of time. Finally, based on multifractal extension of DCCA, we find that the cross-correlations are multifractal and high oil prices partly contribute to food crisis during the period of 2006-mid-2008.
Quality of statistical reporting in developmental disability journals.
Namasivayam, Aravind K; Yan, Tina; Wong, Wing Yiu Stephanie; van Lieshout, Pascal
2015-12-01
Null hypothesis significance testing (NHST) dominates quantitative data analysis, but its use is controversial and has been heavily criticized. The American Psychological Association has advocated the reporting of effect sizes (ES), confidence intervals (CIs), and statistical power analysis to complement NHST results to provide a more comprehensive understanding of research findings. The aim of this paper is to carry out a sample survey of statistical reporting practices in two journals with the highest h5-index scores in the areas of developmental disability and rehabilitation. Using a checklist that includes critical recommendations by American Psychological Association, we examined 100 randomly selected articles out of 456 articles reporting inferential statistics in the year 2013 in the Journal of Autism and Developmental Disorders (JADD) and Research in Developmental Disabilities (RDD). The results showed that for both journals, ES were reported only half the time (JADD 59.3%; RDD 55.87%). These findings are similar to psychology journals, but are in stark contrast to ES reporting in educational journals (73%). Furthermore, a priori power and sample size determination (JADD 10%; RDD 6%), along with reporting and interpreting precision measures (CI: JADD 13.33%; RDD 16.67%), were the least reported metrics in these journals, but not dissimilar to journals in other disciplines. To advance the science in developmental disability and rehabilitation and to bridge the research-to-practice divide, reforms in statistical reporting, such as providing supplemental measures to NHST, are clearly needed.
Comparing Smoking Cessation Outcomes in Nurse-Led and Physician-Led Primary Care Visits.
Byers, Marcia A; Wright, Patricia; Tilford, John Mick; Nemeth, Lynne S; Matthews, Ellyn; Mitchell, Anita
Smoking is a significant public health concern in the United States, yet 50% of patients do not receive recommended tobacco use screening and counseling. This project compared smoking cessation rates in newly reimbursable nurse-led wellness visits with rates in physician-led visits. Although the findings were not statistically significant, they suggested that smoking cessation is at least equivalent in patients who attend nurse-led visits compared with physician-led visits and may be higher.
Susukida, Ryoko; Crum, Rosa M; Ebnesajjad, Cyrus; Stuart, Elizabeth A; Mojtabai, Ramin
2017-07-01
To compare randomized controlled trial (RCT) sample treatment effects with the population effects of substance use disorder (SUD) treatment. Statistical weighting was used to re-compute the effects from 10 RCTs such that the participants in the trials had characteristics that resembled those of patients in the target populations. Multi-site RCTs and usual SUD treatment settings in the United States. A total of 3592 patients in 10 RCTs and 1 602 226 patients from usual SUD treatment settings between 2001 and 2009. Three outcomes of SUD treatment were examined: retention, urine toxicology and abstinence. We weighted the RCT sample treatment effects using propensity scores representing the conditional probability of participating in RCTs. Weighting the samples changed the significance of estimated sample treatment effects. Most commonly, positive effects of trials became statistically non-significant after weighting (three trials for retention and urine toxicology and one trial for abstinence); also, non-significant effects became significantly positive (one trial for abstinence) and significantly negative effects became non-significant (two trials for abstinence). There was suggestive evidence of treatment effect heterogeneity in subgroups that are under- or over-represented in the trials, some of which were consistent with the differences in average treatment effects between weighted and unweighted results. The findings of randomized controlled trials (RCTs) for substance use disorder treatment do not appear to be directly generalizable to target populations when the RCT samples do not reflect adequately the target populations and there is treatment effect heterogeneity across patient subgroups. © 2017 Society for the Study of Addiction.
Wip1 and p53 contribute to HTLV-1 Tax-induced tumorigenesis
2012-01-01
Background Human T-cell Leukemia Virus type 1 (HTLV-1) infects 20 million individuals world-wide and causes Adult T-cell Leukemia/Lymphoma (ATLL), a highly aggressive T-cell cancer. ATLL is refractory to treatment with conventional chemotherapy and fewer than 10% of afflicted individuals survive more than 5 years after diagnosis. HTLV-1 encodes a viral oncoprotein, Tax, that functions in transforming virus-infected T-cells into leukemic cells. All ATLL cases are believed to have reduced p53 activity although only a minority of ATLLs have genetic mutations in their p53 gene. It has been suggested that p53 function is inactivated by the Tax protein. Results Using genetically altered mice, we report here that Tax expression does not achieve a functional equivalence of p53 inactivation as that seen with genetic mutation of p53 (i.e. a p53−/− genotype). Thus, we find statistically significant differences in tumorigenesis between Tax+p53+/+versus Tax+p53−/− mice. We also find a role contributed by the cellular Wip1 phosphatase protein in tumor formation in Tax transgenic mice. Notably, Tax+Wip1−/− mice show statistically significant reduced prevalence of tumorigenesis compared to Tax+Wip1+/+ counterparts. Conclusions Our findings provide new insights into contributions by p53 and Wip1 in the in vivo oncogenesis of Tax-induced tumors in mice. PMID:23256545
An Application of Context- and Problem-Based Learning (C-PBL) into Teaching Thermodynamics
NASA Astrophysics Data System (ADS)
Baran, Mukadder; Sozbilir, Mustafa
2017-05-01
This study aims to investigate the applicability of context- and problem-based learning (C-PBL) into teaching thermodynamics and to examine its influence on the students' achievements in chemistry, retention of knowledge, students' attitudes, motivation and interest towards chemistry. The embedded mixed method design was utilized with a group of 13 chemistry students in a 2-year program of "Medical Laboratory and Techniques" at a state university in an underdeveloped city at the southeastern region of Turkey. The research data were collected via questionnaires regarding the students' attitudes, motivation and interest in chemistry, an achievement test on "thermodynamics" and interviews utilized to find out the applicability of C-PBL into thermodynamics. The findings demonstrated that C-PBL led a statistically significant increase in the students' achievement in thermodynamics and their interest in chemistry, while no statistically significant difference was observed in the students' attitudes and motivation towards chemistry before and after the intervention. The interviews revealed that C-PBL developed not only the students' communication skills but also their skills in using time effectively, making presentations, reporting research results and using technology. It was also found to increase their self-confidence together with the positive attitudes towards C-PBL and being able to associate chemistry with daily life. In light of these findings, it could be stated that it will be beneficial to increase the use of C-PBL in teaching chemistry.
Bang, Lasse; Rø, Øyvind; Endestad, Tor
2018-01-01
Studies point to white matter (WM) microstructure alterations in both adolescent and adult patients with anorexia nervosa (AN). These include reduced fractional anisotropy in several WM fiber tracts, suggesting reduced WM integrity. The extent to which these alterations are reversible with recovery from AN is unclear. There is a paucity of research investigating the presence of WM microstructure alterations in recovered AN patients, and results are inconsistent. This study aimed to investigate the presence of WM microstructure alterations in women long-term recovered from AN. Twenty-one adult women who were recovered from AN for at least 1 year were compared to 21 adult comparison women. Participants were recruited via user-organizations for eating disorders, local advertisements, and online forums. Diffusion tensor imaging was used to compare WM microstructure between groups. Correlations between WM microstructure and clinical characteristics were also explored. There were no statistically significant between-group differences in WM microstructure. These null findings remained when employing liberal alpha level thresholds. Furthermore, there were no statistically significant correlations between WM microstructure and clinical characteristics. Our findings showed normal WM microstructure in long-term recovered patients, indicating the alterations observed during the acute phase are reversible. Given the paucity of research and inconsistent findings, future studies are warranted to determine the presence of WM microstructure alterations following recovery from AN. © 2017 Wiley Periodicals, Inc.
Determinants of well-being in North Korea: evidence from the post-famine period.
Schwekendiek, Daniel
2008-12-01
North Korea has survived the breakdown of the communist bloc and has been immune to the democratization process of the 1990s. In spite of national famines and economic collapse, the totalitarian regime in Pyongyang maintains a firm grip on its power. Reliable information on the population's biosocial welfare is scarce. Using height and weight data of 5991 North Korean pre-school children measured in 2002, we investigate determinants of height-for-age z-score (HAZ), weight-for-age z-score (WAZ) and weight-for-height z-score (WHZ) as an indicator for child health. We find a statistically significant impact of the age of the child and of the mother, as well as the sex of the child on HAZ and WAZ. In contrast, social status and wealth proxies at the individual and household level are not statistically significant possibly because of errors in these variables. We do not find a consistent effect for geographic regions or for rural-urban residents either. Yet, urban provinces seem to be better-off. Most importantly, we find that children living in families who benefit from food aid of the United Nations are healthier in terms of HAZ, WAZ and WHZ than those depending on the government. Hence, further delivery of United Nations food aid is likely to mitigate the effects of the ongoing food crisis in North Korea.
Li, Wenting; Wang, Ying; Fang, Xinzhi; Zhou, Mei; Li, Yiqun; Dong, Ying; Wang, Ruozheng
2017-02-21
BACKGROUND The aim of this study was to investigate the expression and the clinicopathologic significance of DNA methyltransferase 3B (DNMT3B), phosphatase and tensin homolog (PTEN) and human MutL homologs 1 (hMLH1) in endometrial carcinomas between Han and Uygur women in Xinjiang. MATERIAL AND METHODS The expression of DNMT3B, PTEN, and hMLH1 in endometrial carcinomas were assessed by immunohistochemistry, followed by an analysis of their relationship to clinical-pathological features and prognosis. RESULTS There were a 61.7% (95/154) overexpression of DNMT3B, 50.0% (77/154) loss of PTEN expression and 18.2% (28/154) loss of hMLH1 expression. The expression of DNMT3B and PTEN in endometrial carcinomas was statistically significantly different between Uygur women and Han women (p=0.001, p=0.010, respectively). DNMT3B expression was statistically significant based on the grade of endometrial carcinomas (p=0.031). PTEN loss was statistically significant between endometrioid carcinomas (ECs) and non endometrioid carcinomas (NECs) (p=0.040). DNMT3B expression was statistically significant in different myometrial invasion groups in Uygur women (p=0.010). Furthermore, the correlation of DNMT3B and PTEN expression was significant in endometrial carcinomas (p=0.021). PTEN expression was statistically significant in the overall survival (OS) rate of women with endometrial cancers (p=0.041). CONCLUSIONS Our findings suggest that PTEN and DNMT3B possess common regulation features as well as certain ethnic differences in expression between Han women and Uygur women. An interaction may exist in the pathogenesis of endometrial carcinoma. DNMT3B was expressed differently in cases of myometrial invasion and PTEN was associated with OS, which suggested that these molecular markers may be useful in the evaluation of the biological behavior of endometrial carcinomas and may be useful indicators of prognosis in women with endometrial carcinomas.
Li, Wenting; Wang, Ying; Fang, Xinzhi; Zhou, Mei; Li, Yiqun; Dong, Ying; Wang, Ruozheng
2017-01-01
Background The aim of this study was to investigate the expression and the clinicopathologic significance of DNA methyltransferase 3B (DNMT3B), phosphatase and tensin homolog (PTEN) and human MutL homologs 1 (hMLH1) in endometrial carcinomas between Han and Uygur women in Xinjiang. Material/Methods The expression of DNMT3B, PTEN, and hMLH1 in endometrial carcinomas were assessed by immunohistochemistry, followed by an analysis of their relationship to clinical-pathological features and prognosis. Results There were a 61.7% (95/154) overexpression of DNMT3B, 50.0% (77/154) loss of PTEN expression and 18.2% (28/154) loss of hMLH1 expression. The expression of DNMT3B and PTEN in endometrial carcinomas was statistically significantly different between Uygur women and Han women (p=0.001, p=0.010, respectively). DNMT3B expression was statistically significant based on the grade of endometrial carcinomas (p=0.031). PTEN loss was statistically significant between endometrioid carcinomas (ECs) and non endometrioid carcinomas (NECs) (p=0.040). DNMT3B expression was statistically significant in different myometrial invasion groups in Uygur women (p=0.010). Furthermore, the correlation of DNMT3B and PTEN expression was significant in endometrial carcinomas (p=0.021). PTEN expression was statistically significant in the overall survival (OS) rate of women with endometrial cancers (p=0.041). Conclusions Our findings suggest that PTEN and DNMT3B possess common regulation features as well as certain ethnic differences in expression between Han women and Uygur women. An interaction may exist in the pathogenesis of endometrial carcinoma. DNMT3B was expressed differently in cases of myometrial invasion and PTEN was associated with OS, which suggested that these molecular markers may be useful in the evaluation of the biological behavior of endometrial carcinomas and may be useful indicators of prognosis in women with endometrial carcinomas. PMID:28220037
Linkage mapping of beta 2 EEG waves via non-parametric regression.
Ghosh, Saurabh; Begleiter, Henri; Porjesz, Bernice; Chorlian, David B; Edenberg, Howard J; Foroud, Tatiana; Goate, Alison; Reich, Theodore
2003-04-01
Parametric linkage methods for analyzing quantitative trait loci are sensitive to violations in trait distributional assumptions. Non-parametric methods are relatively more robust. In this article, we modify the non-parametric regression procedure proposed by Ghosh and Majumder [2000: Am J Hum Genet 66:1046-1061] to map Beta 2 EEG waves using genome-wide data generated in the COGA project. Significant linkage findings are obtained on chromosomes 1, 4, 5, and 15 with findings at multiple regions on chromosomes 4 and 15. We analyze the data both with and without incorporating alcoholism as a covariate. We also test for epistatic interactions between regions of the genome exhibiting significant linkage with the EEG phenotypes and find evidence of epistatic interactions between a region each on chromosome 1 and chromosome 4 with one region on chromosome 15. While regressing out the effect of alcoholism does not affect the linkage findings, the epistatic interactions become statistically insignificant. Copyright 2003 Wiley-Liss, Inc.
Dietary Inflammatory Potential Score and Risk of Breast Cancer: Systematic Review and Meta-analysis.
Zahedi, Hoda; Djalalinia, Shirin; Sadeghi, Omid; Asayesh, Hamid; Noroozi, Mehdi; Gorabi, Armita Mahdavi; Mohammadi, Rasool; Qorbani, Mostafa
2018-02-07
Several studies have been conducted on the relationship between dietary inflammatory potential (DIP) and breast cancer. However, the findings are conflicting. This systematic review and meta-analysis summarizes the findings on the association between DIP and the risk of breast cancer. We used relevant keywords and searched online international electronic databases, including PubMed and NLM Gateway (for Medline), Institute for Scientific Information (ISI), and Scopus for articles published through February 2017. All cross-sectional, case-control, and cohort studies were included in this meta-analysis. Meta-analysis was performed using the random effects meta-analysis method to address heterogeneity among studies. Findings were analyzed statistically. Nine studies were included in the present systematic review and meta-analysis. The total sample size of these studies was 296,102, and the number of participants varied from 1453 to 122,788. The random effects meta-analysis showed a positive and significant association between DIP and the risk of breast cancer (pooled odds ratio, 1.14; 95% confidence interval, 1.01-1.27). The pooled effect size was not statistically significant because of the type of studies, including cohort (pooled relative risk, 1.04; 95% confidence interval, 0.98-1.10) and case-control (pooled odds ratio, 1.63; 95% confidence interval, 0.89-2.37) studies. We found a significant and positive association between higher DIP score and risk of breast cancer. Modifying inflammatory characteristics of diet can substantially reduce the risk of breast cancer. Copyright © 2018 Elsevier Inc. All rights reserved.
Lessick, Susan; Perryman, Carol; Billman, Brooke L; Alpi, Kristine M; De Groote, Sandra L; Babin, Ted D
2016-04-01
The extent to which health sciences librarians are engaged in research is a little-studied question. This study assesses the research activities and attitudes of Medical Library Association (MLA) members, including the influence of work affiliation. An online survey was designed using a combination of multiple-choice and open-ended questions and distributed to MLA members. Responses were analyzed using descriptive statistics, content analysis, and significance testing. The authors used statistical tools and categorized open-ended question topics by the constant comparative method, also applying the broad subject categories used in a prior study. Pearson's chi-square analysis was performed on responses to determine significant differences among respondents employed in three different institutional environments. Analysis showed that 79% of respondents read research articles at least once a month; 58% applied published research studies to practice; 44% had conducted research; 62% reported acting on research had enhanced their libraries; 38% had presented findings; and 34% had authored research articles. Hospital librarians were significantly less likely than academic librarians to have participated in research activities. Highly ranked research benefits, barriers, and competencies of health sciences librarians are described. Findings indicate that health sciences librarians are actively engaged in research activities. Practice implications for practitioners, publishers, and stakeholders are discussed. Results suggest that practitioners can use published research results and results from their own research to affect practice decisions and improve services. Future studies are needed to confirm and extend these findings, including the need for intervention studies to increase research and writing productivity.
Lessick, Susan; Perryman, Carol; Billman, Brooke L.; Alpi, Kristine M.; De Groote, Sandra L.; Babin, Ted D.
2016-01-01
Introduction The extent to which health sciences librarians are engaged in research is a little-studied question. This study assesses the research activities and attitudes of Medical Library Association (MLA) members, including the influence of work affiliation. Methods An online survey was designed using a combination of multiple-choice and open-ended questions and distributed to MLA members. Responses were analyzed using descriptive statistics, content analysis, and significance testing. The authors used statistical tools and categorized open-ended question topics by the constant comparative method, also applying the broad subject categories used in a prior study. Pearson's chi-square analysis was performed on responses to determine significant differences among respondents employed in three different institutional environments. Results Analysis showed that 79% of respondents read research articles at least once a month; 58% applied published research studies to practice; 44% had conducted research; 62% reported acting on research had enhanced their libraries; 38% had presented findings; and 34% had authored research articles. Hospital librarians were significantly less likely than academic librarians to have participated in research activities. Highly ranked research benefits, barriers, and competencies of health sciences librarians are described. Conclusions Findings indicate that health sciences librarians are actively engaged in research activities. Practice implications for practitioners, publishers, and stakeholders are discussed. Results suggest that practitioners can use published research results and results from their own research to affect practice decisions and improve services. Future studies are needed to confirm and extend these findings, including the need for intervention studies to increase research and writing productivity. PMID:27076808
Alikari, Victoria; Sachlas, Athanasios; Giatrakou, Stavroula; Stathoulis, John; Fradelos, Evagelos; Theofilou, Paraskevi; Lavdaniti, Maria; Zyga, Sofia
2017-01-01
An important factor which influences the quality of life of patients with arthritis is the fatigue they experience. The purpose of this study was to assess the relationship between fatigue and quality of life among patients with osteoarthritis and rheumatoid arthritis. Between January 2015 and March 2015, 179 patients with osteoarthritis and rheumatoid arthritis completed the Fatigue Assessment Scale and the Missoula-VITAS Quality of Life Index-15 (MVQoLI-15). The study was conducted in Rehabilitation Centers located in the area of Peloponnese, Greece. Data related to sociodemographic characteristics and their individual medical histories were recorded. Statistical analysis was performed using the IBM SPSS Statistics version 19. The analysis did not reveal statistically significant correlation between fatigue and quality of life neither in the total sample nor among patients with osteoarthritis (r = -0.159; p = 0.126) or rheumatoid arthritis. However, there was a statistically significant relationship between some aspects of fatigue and dimensions of quality of life. Osteoarthritis patients had statistically significant lower MVQoLI-15 score than rheumatoid arthritis patients (13.73 ± 1.811 vs 14.61 ± 1.734) and lower FAS score than rheumatoid patients (26.14 ± 3.668 vs 29.94 ± 3.377) (p-value < 0.001). The finding that different aspects of fatigue may affect dimensions of quality of life may help health care professionals by proposing the early treatment of fatigue in order to gain benefits for quality of life.
Exploring the impact of mindfulness meditation training in pre-licensure and post graduate nurses.
Sanko, Jill; Mckay, Mary; Rogers, Scott
2016-10-01
The complex, high stress, technologically laden healthcare environment compromises providers' ability to be fully present in the moment; especially during patient interactions. This "pulling away" of attention (mindlessness) from the present moment creates an environment where decision making can take place in the absence of thoughtful, deliberate engagement in the task at hand. Mindfulness, can be cultivated through a variety of mindfulness practices. Few schools of nursing or hospitals offer mindfulness training, despite study findings supporting its effectiveness in improving levels of mindfulness, and perceived connections with patients and families. A mindfulness program developed for this study and tailored to nursing was used to provide the mindfulness training. Pre and post training assessments were completed and included administration of the Freiburg Mindfulness Inventory (FMI) and the Defining Issues Test (DIT) of moral judgment version 2. A statistically significant improvement in the FMI scores p=0.003 was found. The pre-licensure group did not show a statistically significant improvement in their FMI scores pre to post training (p=0.281), however the post graduate group did (p=0.004). Statistically significant pre - post scores were found in two schemas of the DIT-2 (P [Post conventional] score, p=0.039 and N2 [Maintaining norms] score, p=0.032). Mindfulness training improves mindfulness and some aspects of ethical decision making in the groups studied as part of this project. The findings of this study are promising and further demonstrate the merits of a mindfulness practice, however aspects of mindfulness training would need to be addressed prior to launching a full scale attempt to incorporate this into a work life or some other quality improvement program. Copyright © 2016 Elsevier Ltd. All rights reserved.
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).
Archibald, Paul C; Parker, Lauren; Thorpe, Roland
2018-04-01
Criminal justice contact-defined as lifetime arrest, parole, or incarceration, seems to exacerbate chronic conditions, and those who are most likely to have had contact with the criminal justice system, such as Black adults, often already have pre-existing disproportionately high rates of stress and chronic conditions due to the social determinants of health that affect underrepresented minorities. Findings from this study suggest that there is a mechanism that links the stressors among Black adults manifested by such factors as family, financial, neighborhood, and personal problems with criminal justice contact to obesity-related health status. Using the National Survey of American Life (NSAL), modified Poisson regression analyses were used to determine the association between criminal justice contact, stressors, and obesity-related health problems among a national sample of Black adults (n = 5008). In the full model, the odds of experiencing obesity-related health problems for Black adults who had criminal justice contact was reduced (PR, 1.23 to 1.14) and not statistically significant. Black adults who reported experiencing family stressors (PR, 1.21; 95% CI, 1.08, 1.36), financial stressors (PR, 1.30; 95% CI, 1.16, 1.47), and personal stressors (PR, 1.16; 95% CI, 1.02, 1.31) were statistically significant and higher than those who reported not experiencing any of these stressors; neighborhood stressors was not statistically significant. The evidence suggests a relationship between the stressors associated with criminal justice contact and obesity-related health status. These findings emphasize the need to further explore the family, financial, and personal stressors for Black adults with criminal justice contact in order to further our understanding of their obesity-related health problems.ᅟ.
Meimandi Parizi, Abdolhamid; Oryan, Ahmad; Haddadi, Shahram; Bigham Sadegh, Amin
2015-01-01
The present study was designed to investigate the effects of DBM and DBM-G90 on bone healing in a rabbit model. Thirty male white albino rabbits were used in this study. An incision was made in all rabbits under general anesthesia directly over the radius in order to expose it. A 10-mm segmental defect was created on the middle portion of each radius. The defects of 10 rabbits (Group I) were filled with DBM Block and Strip (Zimmer, Inc., Warsaw, IN, USA), the defects of 10 rabbits (Group II) were filled with DBM soaked in G90, and the defects of 10 rabbits (Group III/control) were left empty. The rabbits were euthanized at 60 days postoperatively for histopathological and biomechanical evaluation. At the histopathologic level, the defects of the animals in the DBM and DBM-G90 groups showed more advanced healing criteria than those of the control group. In biomechanical findings, there was a statistically significant difference between the injured bones and contralateral normal bones of the control group in terms of measured strength. There was not a statistically significant difference between the treated bones of the DBM and DBM-G90 groups with contralateral normal bones, nor was there a statistically significant difference between the treated bones of the DBM and DBM-G90 groups with the treated bones of the control group, in terms of other biomechanical tests. Based on the histopathological and biomechanical findings, the DBM and DBM-G90 groups demonstrated superior osteogenic potential; however, G90 shows no superiority over DBM on bone healing.
Morris, Robert; Wilson, Leonie; Sturrock, Matthew; Warnock, Neil D; Carrizo, Daniel; Cox, Deborah; Maule, Aaron G; Dalzell, Johnathan J
2017-03-01
Entomopathogenic nematodes (EPNs) employ a sophisticated chemosensory apparatus to detect potential hosts. Understanding the molecular basis of relevant host-finding behaviours could facilitate improved EPN biocontrol approaches, and could lend insight to similar behaviours in economically important mammalian parasites. FMRFamide-like peptides are enriched and conserved across the Phylum Nematoda, and have been linked with motor and sensory function, including dispersal and aggregating behaviours in the free living nematode Caenorhabditis elegans. The RNA interference (RNAi) pathway of Steinernema carpocapsae was characterised in silico, and employed to knockdown the expression of the FMRFamide-like peptide 21 (GLGPRPLRFamide) gene (flp-21) in S. carpocapsae infective juveniles; a first instance of RNAi in this genus, and a first in an infective juvenile of any EPN species. Our data show that 5 mg/ml dsRNA and 50 mM serotonin triggers statistically significant flp-21 knockdown (-84%***) over a 48 h timecourse, which inhibits host-finding (chemosensory), dispersal, hyperactive nictation and jumping behaviours. However, whilst 1 mg/ml dsRNA and 50 mM serotonin also triggers statistically significant flp-21 knockdown (-51%**) over a 48 h timecourse, it does not trigger the null sensory phenotypes; statistically significant target knockdown can still lead to false negative results, necessitating appropriate experimental design. SPME GC-MS volatile profiles of two EPN hosts, Galleria mellonella and Tenebrio molitor reveal an array of shared and unique compounds; these differences had no impact on null flp-21 RNAi phenotypes for the behaviours assayed. Localisation of flp-21 / FLP-21 to paired anterior neurons by whole mount in situ hybridisation and immunocytochemistry corroborates the RNAi data, further suggesting a role in sensory modulation. These data can underpin efforts to study these behaviours in other economically important parasites, and could facilitate molecular approaches to EPN strain improvement for biocontrol.
Ultrasonographic Features of Papillary Thyroid Carcinoma in Patients with Graves' Disease
Chung, Jin Ook; Cho, Dong Hyeok; Chung, Dong Jin
2010-01-01
Background/Aims To characterize ultrasonographic findings in papillary thyroid carcinoma (PTC) combined with Graves' disease. Methods Medical records and ultrasonographic findings of 1,013 patients with Graves' disease and 3,380 patients without Graves' disease were analyzed retrospectively. A diagnosis of PTC was based on a pathologic examination. Results The frequency of hypoechogenicity was lower in patients with PTC and Graves' disease than in patients with PTC alone (p < 0.05). The frequency of perinodular blood flow in patients with PTC and Graves' disease was significantly higher than in those with PTC alone (p < 0.05). PTC combined with Graves' disease was characterized by more ill-defined borders and less frequency of overall calcification, punctate calcification, and heterogeneous echogenicity, although the difference was not statistically significant. Conclusions Our results suggest that patients with Graves' disease more frequently have atypical PTC findings on ultrasonography. PMID:20195406
Lauterbach, M D; Raz, S; Sander, C J
2001-07-01
The authors examined the differential effects of neonatal respiratory distress syndrome (RDS)--a condition associated with elevated risk for neonatal hypoxia-ischemia--on the cognitive development of the two sexes. The authors also attempted to establish whether the severity of respiratory distress is linked to cognitive outcome. Findings revealed an appreciable female advantage in cognitive recovery from RDS, yet the association between severity of RDS and outcome did not reach conventional statistical significance level. The sex effect on intelligence test performance was significantly greater for nonverbal subtests than for verbal ones. These results augment earlier findings of sex differences in cognitive recovery from perinatal intracranial hemorrhage. The current investigation also extends these results to a population of children at neonatal hypoxic risk for whom early brain injury was excluded on the basis of neonatal cranial ultrasound findings.
Guitérrez-Bedmar, Mario; Seguí-Gómez, María; Gómez-Gracia, Enrique; Bes-Rastrollo, Maira; Martínez-González, Miguel A
2009-01-01
We aimed to evaluate the association between smoking, changes in smoking, and quality of life in a cohort of Spanish university graduates. Smoking habits were self-reported at baseline and four years later. Quality of life was assessed using the Short Form-36 (SF-36) at year 4. Statistical differences in SF-36 scores between groups were determined using ANCOVA with age and sex as covariates. Out of 5,234 eligible participants over 2000–2006, there were 2,639 non-smoker participants, 1,419 ex-smokers, and 1,048 smokers. Within the previous four years, 435 participants became recent quitters and 205 starters. Comparing smoking and health status in year 4, non-smokers showed better scores than the other categories of ever smoking in all dimensions except in the vitality scale value, which was similar in non-smokers and in those smoking less than 15 cigarettes/day. Comparing changes in smoking and health in year 4, continuing smokers had statistically significant worse scores than non-smokers in general health, social functioning, role-emotional and mental health, whereas recent quitters showed statistically significant improvements in role-emotional and mental health over those who had continued smoking or those who became smokers. Our findings support a dose-response relationship between cigarette consumption and a worse quality of life in general and mental health in particular. They also support that changes in smoking have an impact on health. PMID:19440285
Ndwandwe, Duduzile; Uthman, Olalekan A; Adamu, Abdu A; Sambala, Evanson Z; Wiyeh, Alison B; Olukade, Tawa; Bishwajit, Ghose; Yaya, Sanni; Okwo-Bele, Jean-Marie; Wiysonge, Charles S
2018-04-24
Understanding the gaps in missed opportunities for vaccination (MOV) in sub-Saharan Africa would inform interventions for improving immunisation coverage to achieving universal childhood immunisation. We aimed to conduct a multicountry analyses to decompose the gap in MOV between poor and non-poor in SSA. We used cross-sectional data from 35 Demographic and Health Surveys in SSA conducted between 2007 and 2016. Descriptive statistics used to understand the gap in MOV between the urban poor and non-poor, and across the selected covariates. Out of the 35 countries included in this analysis, 19 countries showed pro-poor inequality, 5 showed pro-non-poor inequality and remaining 11 countries showed no statistically significant inequality. Among the countries with statistically significant pro-illiterate inequality, the risk difference ranged from 4.2% in DR Congo to 20.1% in Kenya. Important factors responsible for the inequality varied across countries. In Madagascar, the largest contributors to inequality in MOV were media access, number of under-five children, and maternal education. However, in Liberia media access narrowed inequality in MOV between poor and non-poor households. The findings indicate that in most SSA countries, children belonging to poor households are most likely to have MOV and that socio-economic inequality in is determined not only by health system functions, but also by factors beyond the scope of health authorities and care delivery system. The findings suggest the need for addressing social determinants of health.
The lambda sign: a new radiographic indicator of latent syndesmosis instability.
Ryan, Ltc Paul; Hills, Maj Chad; Chang, James; Wilson, Cpt David
2014-09-01
Latent syndesmotic instability is a common cause of chronic ankle pain. The diagnosis is not readily apparent on static imaging as the fibula remains reduced. The hypothesis of this study was that a previously undescribed novel finding on coronal MRI (lambda sign) is an independent indicator of latent syndesmosis instability. We also report on the utility of classic radiographic and physical exam findings. A total of 23 patients with latent syndesmotic instability diagnosed via arthroscopy (group I) were compared to a cohort of 40 patients who were found to have a stable syndesmosis during arthroscopy for unrelated conditions (group II). A retrospective chart review was performed evaluating their clinical history, preoperative physical examination, and radiologic findings. The lambda sign is a high intensity signal seen on coronal MR imaging that resembles the Greek letter lambda. All of the physical exam findings tested were statistically significant. Pain at the syndesmosis had the highest sensitivity (83%), while pain reproduced with the proximal squeeze test resulted in the highest specificity (89%). The external rotation stress test had the highest positive predictive value (75%). Of the radiographic examinations performed, only the lambda sign was found to have statistical significance with a sensitivity of 75% and a specificity of 63%. The presence of a lambda sign on the MRI of patients with physical exam findings suggestive of syndesmotic pain was highly sensitive (75%) and specific (85%). The lambda sign noted on the coronal MRI was both sensitive and specific for injuries involving greater than 2 mm of diastasis on arthroscopic stress examination of the syndesmosis. While neither the lambda sign nor any other finding on physical or radiographic examination represented an independent predictor of syndesmotic instability, the presence of a lambda sign in concert with positive physical exam findings might help health care providers determine which patients might benefit from operative intervention or referral. Level III, case control study. © The Author(s) 2014.
Alabousi, Abdullah; Patlas, Michael N; Meshki, Malek; Monteiro, Sandra; Katz, Douglas S
2016-04-01
The purpose of our study was to retrospectively evaluate the prevalence and clinical relevance of positive abdominal and pelvic CT findings for patients 65 years of age and older, when compared with all other scanned adult Emergency Department (ED) patients, at a single tertiary care hospital. Our hypothesis was that there is an increased prevalence and clinical relevance of positive abdominal/pelvic CT findings in senior patients. A research ethics board-approved retrospective review of all adult patients who underwent an emergency CT of the abdomen and pelvis for acute nontraumatic abdominal and/or pelvic signs and symptoms was performed. Two thousand one hundred two patients between October 1, 2011, and September 30, 2013, were reviewed. Six hundred thirty-one patients were included in the <65 group (298 men and 333 women; mean age 46, age range 18-64), and 462 were included in the >65 group (209 men and 253 women; mean age 77.6, age range 65-99). Overall, there were more positive CT findings for patients <65 (389 positive cases, 61.6 %) compared with the >65 group (257 positive cases, 55.6 %), which was a statistically significant difference (p < 0.03). Moreover, with the exception of complicated appendicitis cases, which were more common in the >65 group, there were no statistically significant differences in the clinical/surgical relevance of the positive CT findings between the two groups. The findings of our retrospective study therefore refute our hypothesis that there is an increased prevalence of positive abdominal CT findings in patients >65. This may be related to ED physicians at our institution being more hesitant to order CT examinations for the younger population, presumably due to radiation concerns. However, older patients in our series were more likely to present with complicated appendicitis, and a lower threshold for ordering CT examinations of the abdomen and pelvis in this patient population should therefore be considered.
When Null Hypothesis Significance Testing Is Unsuitable for Research: A Reassessment.
Szucs, Denes; Ioannidis, John P A
2017-01-01
Null hypothesis significance testing (NHST) has several shortcomings that are likely contributing factors behind the widely debated replication crisis of (cognitive) neuroscience, psychology, and biomedical science in general. We review these shortcomings and suggest that, after sustained negative experience, NHST should no longer be the default, dominant statistical practice of all biomedical and psychological research. If theoretical predictions are weak we should not rely on all or nothing hypothesis tests. Different inferential methods may be most suitable for different types of research questions. Whenever researchers use NHST they should justify its use, and publish pre-study power calculations and effect sizes, including negative findings. Hypothesis-testing studies should be pre-registered and optimally raw data published. The current statistics lite educational approach for students that has sustained the widespread, spurious use of NHST should be phased out.
[Functional impairment and quality of life after rectal cancer surgery].
Mora, Laura; Zarate, Alba; Serra-Aracil, Xavier; Pallisera, Anna; Serra, Sheila; Navarro-Soto, Salvador
2018-01-01
This study determines the quality of life and the anorectal function of these patients. Observational study of two cohorts comparing patients undergoing rectal tumor surgery using TaETM or conventional ETM after a minimum of six months of intestinal transit reconstruction. EORTC-30, EORTC-29 quality of life questionnaires and the anorectal function assessment questionnaire (LARS score) are applied. General variables are also collected. 31 patients between 2011 and 2014: 15 ETM group and 16 TaETM. We do not find statistically significant differences in quality of life questionnaires or in anorectal function. Statistically significant general variables: longer surgical time in the TaETM group. Nosocomial infection and minor suture failure in the TaETM group. The performance of TaETM achieves the same results in terms of quality of life and anorectal function as conventional ETM. Copyright: © 2018 Permanyer.
Duncan, Michael J; Eyre, Emma Lj; Bryant, Elizabeth; Seghers, Jan; Galbraith, Niall; Nevill, Alan M
2017-04-01
Overall, 544 children (mean age ± standard deviation = 14.2 ± .94 years) completed self-report measures of physical activity goal content, behavioral regulations, and physical activity behavior. Body mass index was determined from height and mass. The indirect effect of intrinsic goal content on physical activity was statistically significant via autonomous ( b = 162.27; 95% confidence interval [89.73, 244.70]), but not controlled motivation ( b = 5.30; 95% confidence interval [-39.05, 45.16]). The indirect effect of extrinsic goal content on physical activity was statistically significant via autonomous ( b = 106.25; 95% confidence interval [63.74, 159.13]) but not controlled motivation ( b = 17.28; 95% confidence interval [-31.76, 70.21]). Weight status did not alter these findings.
When Null Hypothesis Significance Testing Is Unsuitable for Research: A Reassessment
Szucs, Denes; Ioannidis, John P. A.
2017-01-01
Null hypothesis significance testing (NHST) has several shortcomings that are likely contributing factors behind the widely debated replication crisis of (cognitive) neuroscience, psychology, and biomedical science in general. We review these shortcomings and suggest that, after sustained negative experience, NHST should no longer be the default, dominant statistical practice of all biomedical and psychological research. If theoretical predictions are weak we should not rely on all or nothing hypothesis tests. Different inferential methods may be most suitable for different types of research questions. Whenever researchers use NHST they should justify its use, and publish pre-study power calculations and effect sizes, including negative findings. Hypothesis-testing studies should be pre-registered and optimally raw data published. The current statistics lite educational approach for students that has sustained the widespread, spurious use of NHST should be phased out. PMID:28824397
A study of statistics anxiety levels of graduate dental hygiene students.
Welch, Paul S; Jacks, Mary E; Smiley, Lynn A; Walden, Carolyn E; Clark, William D; Nguyen, Carol A
2015-02-01
In light of increased emphasis on evidence-based practice in the profession of dental hygiene, it is important that today's dental hygienist comprehend statistical measures to fully understand research articles, and thereby apply scientific evidence to practice. Therefore, the purpose of this study was to investigate statistics anxiety among graduate dental hygiene students in the U.S. A web-based self-report, anonymous survey was emailed to directors of 17 MSDH programs in the U.S. with a request to distribute to graduate students. The survey collected data on statistics anxiety, sociodemographic characteristics and evidence-based practice. Statistic anxiety was assessed using the Statistical Anxiety Rating Scale. Study significance level was α=0.05. Only 8 of the 17 invited programs participated in the study. Statistical Anxiety Rating Scale data revealed graduate dental hygiene students experience low to moderate levels of statistics anxiety. Specifically, the level of anxiety on the Interpretation Anxiety factor indicated this population could struggle with making sense of scientific research. A decisive majority (92%) of students indicated statistics is essential for evidence-based practice and should be a required course for all dental hygienists. This study served to identify statistics anxiety in a previously unexplored population. The findings should be useful in both theory building and in practical applications. Furthermore, the results can be used to direct future research. Copyright © 2015 The American Dental Hygienists’ Association.
2013-01-01
Background The advent of genome-wide association studies has led to many novel disease-SNP associations, opening the door to focused study on their biological underpinnings. Because of the importance of analyzing these associations, numerous statistical methods have been devoted to them. However, fewer methods have attempted to associate entire genes or genomic regions with outcomes, which is potentially more useful knowledge from a biological perspective and those methods currently implemented are often permutation-based. Results One property of some permutation-based tests is that their power varies as a function of whether significant markers are in regions of linkage disequilibrium (LD) or not, which we show from a theoretical perspective. We therefore develop two methods for quantifying the degree of association between a genomic region and outcome, both of whose power does not vary as a function of LD structure. One method uses dimension reduction to “filter” redundant information when significant LD exists in the region, while the other, called the summary-statistic test, controls for LD by scaling marker Z-statistics using knowledge of the correlation matrix of markers. An advantage of this latter test is that it does not require the original data, but only their Z-statistics from univariate regressions and an estimate of the correlation structure of markers, and we show how to modify the test to protect the type 1 error rate when the correlation structure of markers is misspecified. We apply these methods to sequence data of oral cleft and compare our results to previously proposed gene tests, in particular permutation-based ones. We evaluate the versatility of the modification of the summary-statistic test since the specification of correlation structure between markers can be inaccurate. Conclusion We find a significant association in the sequence data between the 8q24 region and oral cleft using our dimension reduction approach and a borderline significant association using the summary-statistic based approach. We also implement the summary-statistic test using Z-statistics from an already-published GWAS of Chronic Obstructive Pulmonary Disorder (COPD) and correlation structure obtained from HapMap. We experiment with the modification of this test because the correlation structure is assumed imperfectly known. PMID:24199751
Swanson, David M; Blacker, Deborah; Alchawa, Taofik; Ludwig, Kerstin U; Mangold, Elisabeth; Lange, Christoph
2013-11-07
The advent of genome-wide association studies has led to many novel disease-SNP associations, opening the door to focused study on their biological underpinnings. Because of the importance of analyzing these associations, numerous statistical methods have been devoted to them. However, fewer methods have attempted to associate entire genes or genomic regions with outcomes, which is potentially more useful knowledge from a biological perspective and those methods currently implemented are often permutation-based. One property of some permutation-based tests is that their power varies as a function of whether significant markers are in regions of linkage disequilibrium (LD) or not, which we show from a theoretical perspective. We therefore develop two methods for quantifying the degree of association between a genomic region and outcome, both of whose power does not vary as a function of LD structure. One method uses dimension reduction to "filter" redundant information when significant LD exists in the region, while the other, called the summary-statistic test, controls for LD by scaling marker Z-statistics using knowledge of the correlation matrix of markers. An advantage of this latter test is that it does not require the original data, but only their Z-statistics from univariate regressions and an estimate of the correlation structure of markers, and we show how to modify the test to protect the type 1 error rate when the correlation structure of markers is misspecified. We apply these methods to sequence data of oral cleft and compare our results to previously proposed gene tests, in particular permutation-based ones. We evaluate the versatility of the modification of the summary-statistic test since the specification of correlation structure between markers can be inaccurate. We find a significant association in the sequence data between the 8q24 region and oral cleft using our dimension reduction approach and a borderline significant association using the summary-statistic based approach. We also implement the summary-statistic test using Z-statistics from an already-published GWAS of Chronic Obstructive Pulmonary Disorder (COPD) and correlation structure obtained from HapMap. We experiment with the modification of this test because the correlation structure is assumed imperfectly known.
NASA Technical Reports Server (NTRS)
Stefanski, Philip L.
2015-01-01
Commercially available software packages today allow users to quickly perform the routine evaluations of (1) descriptive statistics to numerically and graphically summarize both sample and population data, (2) inferential statistics that draws conclusions about a given population from samples taken of it, (3) probability determinations that can be used to generate estimates of reliability allowables, and finally (4) the setup of designed experiments and analysis of their data to identify significant material and process characteristics for application in both product manufacturing and performance enhancement. This paper presents examples of analysis and experimental design work that has been conducted using Statgraphics®(Registered Trademark) statistical software to obtain useful information with regard to solid rocket motor propellants and internal insulation material. Data were obtained from a number of programs (Shuttle, Constellation, and Space Launch System) and sources that include solid propellant burn rate strands, tensile specimens, sub-scale test motors, full-scale operational motors, rubber insulation specimens, and sub-scale rubber insulation analog samples. Besides facilitating the experimental design process to yield meaningful results, statistical software has demonstrated its ability to quickly perform complex data analyses and yield significant findings that might otherwise have gone unnoticed. One caveat to these successes is that useful results not only derive from the inherent power of the software package, but also from the skill and understanding of the data analyst.
Message framing and credibility: application in dental services.
Arora, R
2000-01-01
This study uses an experimental approach to test the influence of message framing and credibility on the attitude toward a dental exam and consumers' intention to use the dental office. The findings indicate a strong effect of credibility on attitude as well as intention. The influence of framing is also statistically significant. Implications for marketers in terms of message strategy are discussed.
Self-Repairing of Chinese Science and Engineering Majors in Oral English
ERIC Educational Resources Information Center
Wang, Weiwei; Xu, Xiaoqin
2015-01-01
This study employs corpus analytical tools to carry out a systematic study on Chinese Science and Engineering Majors' (SEMs') use of self-repair in their oral English. The study aims to find out the overall feature of using self-repair by SEMs and to see if there exists statistically significant difference of using self-repair across different…
ERIC Educational Resources Information Center
Zielinska, Dorota
2003-01-01
Outlines the technical writing tutorial (TWT) that precedes an advanced English as a second language (ESL) writing course for students of English Philology at the Jagiellonian University, Poland. Finds a statistically significant increase in the performance of the students who had taken the TWT. Indicates that technical writing books and journals…
The Effect of Education on Economic Growth in Greece over the 1960-2000 Period
ERIC Educational Resources Information Center
Tsamadias, Constantinos; Prontzas, Panagiotis
2012-01-01
This paper examines the impact of education on economic growth in Greece over the period 1960-2000 by applying the model introduced by Mankiw, Romer, and Weil. The findings of the empirical analysis reveal that education had a positive and statistically significant effect on economic growth in Greece over the period 1960-2000. The econometric…
ERIC Educational Resources Information Center
Zaif, Figen; Karapinar, Aydin; Yangin Eksi, Gonca
2017-01-01
The authors explore the effect of medium of instruction on students' attainments at a large state university in Turkey in the Department of Business Administration. The findings indicate no statistically significant difference in grades of 386 students with respect to medium of instruction. As for entry rankings however, those in the…
ERIC Educational Resources Information Center
Uguak, Uget Apayo
2011-01-01
The study targets children in especially difficult circumstances from 8-14 years; and explores the importance of psychosocial needs for the PTSD and displaced children in schools. Out of 235 participants, descriptive statistics indicated that 63 children are traumatized. Based on ANOVA findings, the result revealed that there is significant effect…
ERIC Educational Resources Information Center
Kadhi, Tau; Holley, D.
2010-01-01
The following report gives the statistical findings of the July 2010 TMSL Bar results. Procedures: Data is pre-existing and was given to the Evaluator by email from the Registrar and Dean. Statistical analyses were run using SPSS 17 to address the following research questions: 1. What are the statistical descriptors of the July 2010 overall TMSL…
Using prediction markets to estimate the reproducibility of scientific research.
Dreber, Anna; Pfeiffer, Thomas; Almenberg, Johan; Isaksson, Siri; Wilson, Brad; Chen, Yiling; Nosek, Brian A; Johannesson, Magnus
2015-12-15
Concerns about a lack of reproducibility of statistically significant results have recently been raised in many fields, and it has been argued that this lack comes at substantial economic costs. We here report the results from prediction markets set up to quantify the reproducibility of 44 studies published in prominent psychology journals and replicated in the Reproducibility Project: Psychology. The prediction markets predict the outcomes of the replications well and outperform a survey of market participants' individual forecasts. This shows that prediction markets are a promising tool for assessing the reproducibility of published scientific results. The prediction markets also allow us to estimate probabilities for the hypotheses being true at different testing stages, which provides valuable information regarding the temporal dynamics of scientific discovery. We find that the hypotheses being tested in psychology typically have low prior probabilities of being true (median, 9%) and that a "statistically significant" finding needs to be confirmed in a well-powered replication to have a high probability of being true. We argue that prediction markets could be used to obtain speedy information about reproducibility at low cost and could potentially even be used to determine which studies to replicate to optimally allocate limited resources into replications.
Management of vocal fold scar with autologous fat implantation: perceptual results.
Neuenschwander, M C; Sataloff, R T; Abaza, M M; Hawkshaw, M J; Reiter, D; Spiegel, J R
2001-06-01
Vocal fold scar disrupts the mucosal wave and interferes with glottic closure. Treatment involves a multidisciplinary approach that includes voice therapy, medical management, and sometimes surgery. We reviewed the records of the first eight patients who underwent autologous fat implantation for vocal fold scar. Information on the etiology of scar, physical findings, and prior interventions were collected. Videotapes of videostroboscopic findings and perceptual voice ratings [Grade, Roughness, Breathiness, Asthenia, Strain (GRBAS)] were randomized and analyzed independently by four blinded observers. Etiology of scar included mass excision (7), vocal fold stripping (3), congenital sulcus (2), and hemorrhage (1). Prior surgical procedures performed included thyroplasty (1), autologous fat injection (9), excision of scar (2), and lysis of adhesions (2). Strobovideolaryngoscopy: Statistically significant improvement was found in glottic closure, mucosal wave, and stiffness (P = 0.05). Perceptual ratings (GRBAS): Statistically significant improvement was found in all five parameters, including overall Grade, Roughness, Breathiness, Asthenia, and Strain (P = 0.05). Patients appear to have improved vocal fold function and quality of voice after autologous fat implantation in the vocal fold. Autologous fat implantation is an important adjunctive procedure in the management of vocal fold scar, and a useful addition to the armamentarium of the experienced phonomicrosurgeon.
Building personal and professional resources of resilience and agility in the healthcare workplace.
Pipe, Teresa Britt; Buchda, Vicki L; Launder, Susan; Hudak, Barb; Hulvey, Lynne; Karns, Katherine E; Pendergast, Debra
2012-02-01
This article describes the rationale, implementation and results of a pilot study evaluating the personal and organizational impact of an educational intervention on the stress of health team members. The compelling imperative for the project was to find a positive and effective way to address the documented stress levels of healthcare workers. Pilot study of oncology staff (n=29) and healthcare leaders (n=15) exploring the impact of a positive coping approach on Personal and Organizational Quality Assessment-Revised (POQA-R) scores at baseline and 7 months using paired t-tests. Personal and organizational indicators of stress decreased in the expected directions in both groups over the time intervals. The majority of POQA-R categories were statistically significantly improved in the oncology staff, and many of the categories were statistically significantly improved in the leadership group. The findings from this project demonstrate that stress and its symptoms are problematic issues for hospital and ambulatory clinic staff as evidenced by baseline measures of distress. Further, a workplace intervention was feasible and effective in promoting positive strategies for coping and enhancing well-being, personally and organizationally. Copyright © 2011 John Wiley & Sons, Ltd.
NASA Astrophysics Data System (ADS)
Taştan, Özgecan; Yalçınkaya, Eylem; Boz, Yezdan
2008-10-01
The aim of this study is to compare the effectiveness of conceptual change text instruction (CCT) in the context of energy in chemical reactions. The subjects of the study were 60, 10th grade students at a high school, who were in two different classes and taught by the same teacher. One of the classes was randomly selected as the experimental group in which CCT instruction was applied, and the other as the control group in which traditional teaching method was used. The data were obtained through the use of Energy Concept Test (ECT), the Attitude Scale towards Chemistry (ASC) and Science Process Skill Test (SPST). In order to find out the effect of the conceptual change text on students' learning of energy concept, independent sample t-tests, ANCOVA (analysis of covariance) and ANOVA (analysis of variance) were used. Results revealed that there was a statistically significant mean difference between the experimental and control group in terms of students' ECT total mean scores; however, there was no statistically significant difference between the experimental and control group in terms of students' attitude towards chemistry. These findings suggest that conceptual change text instruction enhances the understanding and achievement.
Epidemiological predictors of metabolic syndrome in urban West Bengal, India.
Chakraborty, Sasthi Narayan; Roy, Sunetra Kaviraj; Rahaman, Md Abdur
2015-01-01
Metabolic syndrome is one of the emerging health problems of the world. Its prevalence is high in urban areas. Though pathogenesis is complex, but the interaction of obesity, sedentary lifestyle, dietary, and genetic factors are known as contributing factors. Community-based studies were very few to find out the prevalence or predictors of the syndrome. To ascertain the prevalence and epidemiological predictors of metabolic syndrome. A total of 690 study subjects were chosen by 30 clusters random sampling method from 43 wards of Durgapur city. Data were analyzed in SPSS version 20 software and binary logistic regression was done to find out statistical significance of the predictors. Among 32.75% of the study population was diagnosed as metabolic syndrome according to National Cholesterol Education Program Adult Treatment Panel III definition with a modification for Asia Pacific cut-off of waist circumference. Odds were more among females (2.43), upper social class (14.89), sedentary lifestyle (17.00), and positive family history. The overall prevalence of metabolic syndrome was high in urban areas of Durgapur. Increased age, female gender, higher social status, sedentary lifestyle, positive family history, and higher education were the statistically significant predictors of metabolic syndrome.
Epidemiology of mixed martial arts and youth violence in an ethnically diverse sample.
Hishinuma, Earl S; Umemoto, Karen N; Nguyen, Toan Gia; Chang, Janice Y; Bautista, Randy Paul M
2012-01-01
Mixed martial arts' (MMAs) growing international popularity has rekindled the discussion on the advantages (e.g., exercise) and disadvantages (e.g., possible injury) of contact sports. This study was the first of its kind to examine the psychosocial aspects of MMA and youth violence using an epidemiologic approach with an Asian American and Pacific Islander (AAPI) adolescent sample (N = 881). The results were consistent with the increased popularity of MMA with 52% (adolescent males = 73%, adolescent females = 39%) enjoying watching MMA and 24% (adolescent males = 39%, adolescent females = 13%) practicing professional fight moves with friends. Although statistically significant ethnic differences were found for the two MMA items on a bivariate level, these findings were not statistically significant when considering other variables in the model. The bivariate results revealed a cluster of risk-protective factors. Regarding the multiple regression findings, although enjoying watching MMA remained associated with positive attitudes toward violence and practicing fight moves remained associated with negative out-group orientation, the MMA items were not associated with unique variances of youth violence perpetration and victimization. Implications included the need for further research that includes other diverse samples, more comprehensive and objective MMA and violence measures, and observational and intervention longitudinal studies.
RAId_DbS: Peptide Identification using Database Searches with Realistic Statistics
Alves, Gelio; Ogurtsov, Aleksey Y; Yu, Yi-Kuo
2007-01-01
Background The key to mass-spectrometry-based proteomics is peptide identification. A major challenge in peptide identification is to obtain realistic E-values when assigning statistical significance to candidate peptides. Results Using a simple scoring scheme, we propose a database search method with theoretically characterized statistics. Taking into account possible skewness in the random variable distribution and the effect of finite sampling, we provide a theoretical derivation for the tail of the score distribution. For every experimental spectrum examined, we collect the scores of peptides in the database, and find good agreement between the collected score statistics and our theoretical distribution. Using Student's t-tests, we quantify the degree of agreement between the theoretical distribution and the score statistics collected. The T-tests may be used to measure the reliability of reported statistics. When combined with reported P-value for a peptide hit using a score distribution model, this new measure prevents exaggerated statistics. Another feature of RAId_DbS is its capability of detecting multiple co-eluted peptides. The peptide identification performance and statistical accuracy of RAId_DbS are assessed and compared with several other search tools. The executables and data related to RAId_DbS are freely available upon request. PMID:17961253
Electron Heating at Kinetic Scales in Magnetosheath Turbulence
NASA Technical Reports Server (NTRS)
Chasapis, Alexandros; Matthaeus, W. H.; Parashar, T. N.; Lecontel, O.; Retino, A.; Breuillard, H.; Khotyaintsev, Y.; Vaivads, A.; Lavraud, B.; Eriksson, E.;
2017-01-01
We present a statistical study of coherent structures at kinetic scales, using data from the Magnetospheric Multiscale mission in the Earths magnetosheath. We implemented the multi-spacecraft partial variance of increments (PVI) technique to detect these structures, which are associated with intermittency at kinetic scales. We examine the properties of the electron heating occurring within such structures. We find that, statistically, structures with a high PVI index are regions of significant electron heating. We also focus on one such structure, a current sheet, which shows some signatures consistent with magnetic reconnection. Strong parallel electron heating coincides with whistler emissions at the edges of the current sheet.
Tucak, Zvonimir; Skrivanko, Mario; Posavcević, Stefica; Periskić, Marin; Bosković, Ivica; Jumić, Vlado
2008-09-01
The life of game birds (pheasants) in nature is coupled with a number of difficulties in all seasons of the year. This refers to finding food, breeding, laying eggs, raising the young, fleeing from their natural enemies and lack of protection from unfavorable climatic conditions. The pheasants that live in captivity--aviaries for pheasants--do not have such difficulties--they are fed regularly by quality feed for pheasants, they are protected from bad weather and natural enemies. Our research was aimed at determining the biological value of meat of pheasants grown in the two different settings--in captivity and in nature. The highest weight achieved wild pheasant males (1232.4 +/- 147.36 g). The differences between tested pheasant groups were statistically very high significant (P < 0.001). The differences between groups related to breast weight and tights with drumsticks weight were statistically very high significant (P < 0.001). Between breast parts (%) and legs parts (%) were notified very high (P < 0.001) i.e. high (P = 0.002) differences. The highest weight breast muscles and tights with drumsticks had wild pheasants (282.6 +/- 63.53 g i.e. 206.2 +/- 37.88g). Wilde pheasants had lower part (%) and lighter (g) skin with subcutaneous fatty tissue on breasts. Female pheasants cultivated on both ways had higher skin part (%) and subcutaneous fatty tissue in tights with drumsticks. Related to chemical composition of breast muscles is established statistically significant differences (P < 0.001 i.s. P = 0.040)) in part of Ca (%) and P (%). In wild pheasant tights with drumsticks muscles established statistically very significant (P < 0.001) higher part of moisture, protein and Ca, i.e. statistically very high significant (P < 0.001) lower part of fat and energetic value. Research results indicate that the quality of meat of pheasants grown in nature has higher biological value than the meat of pheasants kept in aviaries, which means it has advantages in human nutrition.
Strous, Rael D; Nolan, Karen A; Lapidus, Raya; Diaz, Libna; Saito, Takuya; Lachman, Herbert M
2003-07-01
We have previously reported that increased aggressive behavior in schizophrenic patients may be associated with a polymorphism at codon 158 of the catechol O-methyltransferase (COMT) gene that encodes a low enzyme activity variant. The finding has been replicated by one group, but not others. The discordant findings could be due to statistical errors or methodological issues in the assessment of aggressive/violent behavior. Consequently, additional studies are needed. Patients with schizophrenia (SZ) were assessed for violent behavior using the Lifetime History of Aggression (LHA) scale, an 11-item questionnaire that includes Aggression, Self-Directed Aggression, and Consequences/Antisocial Behavior subscales. DNA was genotyped for the COMT 158 polymorphism, as well as a functional polymorphism in the monoamine oxidase A (MAOA) gene promoter. Similar to our previously reported findings, a statistically significant association was found between aggressive behavior in SZ and the COMT 158 polymorphism; mean LHA scores were higher in subjects homozygous for 158Met, the low enzyme activity COMT variant (F(2,105) = 5.616, P = 0.005). Analysis of the major LHA subscales revealed that the association with 158Met was due to high scores on the Aggression, and Self-Directed Aggression subscales, but not the Consequences/Antisocial Behavior subscale. No significant association was detected for the MAOA gene alone. Our findings provide further support that COMT is a modifying gene that plays a role in determining interindividual variability in the proclivity for outward and self-directed aggressive behavior found in some schizophrenic patients. Copyright 2003 Wiley-Liss, Inc.
A multiple hold-out framework for Sparse Partial Least Squares.
Monteiro, João M; Rao, Anil; Shawe-Taylor, John; Mourão-Miranda, Janaina
2016-09-15
Supervised classification machine learning algorithms may have limitations when studying brain diseases with heterogeneous populations, as the labels might be unreliable. More exploratory approaches, such as Sparse Partial Least Squares (SPLS), may provide insights into the brain's mechanisms by finding relationships between neuroimaging and clinical/demographic data. The identification of these relationships has the potential to improve the current understanding of disease mechanisms, refine clinical assessment tools, and stratify patients. SPLS finds multivariate associative effects in the data by computing pairs of sparse weight vectors, where each pair is used to remove its corresponding associative effect from the data by matrix deflation, before computing additional pairs. We propose a novel SPLS framework which selects the adequate number of voxels and clinical variables to describe each associative effect, and tests their reliability by fitting the model to different splits of the data. As a proof of concept, the approach was applied to find associations between grey matter probability maps and individual items of the Mini-Mental State Examination (MMSE) in a clinical sample with various degrees of dementia. The framework found two statistically significant associative effects between subsets of brain voxels and subsets of the questions/tasks. SPLS was compared with its non-sparse version (PLS). The use of projection deflation versus a classical PLS deflation was also tested in both PLS and SPLS. SPLS outperformed PLS, finding statistically significant effects and providing higher correlation values in hold-out data. Moreover, projection deflation provided better results. Copyright © 2016 The Author(s). Published by Elsevier B.V. All rights reserved.
Johnson, K E; Sanders, J J; Gellin, R G; Palesch, Y Y
1998-04-01
The purpose of this study was to evaluate the effects of a magnetized water oral irrigator on plaque, calculus and gingival health. 29 patients completed this double-blind crossover study. Each patient was brought to baseline via an oral prophylaxis with a plaque index < or = 1 and a gingival index < or = 1. Subjects used the irrigator for a period of 3 months with the magnet and 3 months without the magnet. After each 3 month interval, data were collected using the plaque index, gingival index, and accretions index. The repeated measures analysis on plaque, gingival and calculus indices yielded a statistically-significant period effect for PlI (p=0.0343), GI (p=0.0091), and approached significance for calculus (p=0.0593). This meant that the effect of irrigation resulted in a decrease of all indices over time. Therefore, the treatment effect on each index was evaluated using only the measurements obtained at the end of the first period (i.e., assuming a parallel design). Irrigation with magnetized water resulted in 64% less calculus compared to the control group. The reduction was statistically significant (p< or =0.02). The reduction by 27% in gingival index was not statistically significant. The reduction in plaque was minimal (2.2%). A strong positive correlation between the plaque index and the Watt accretion index was observed. The magnetized water oral irrigator could be a useful adjunct in the prevention of calculus accumulation in periodontal patients, but appears to have minimal effect on plaque reduction. The results indicated a clinical improvement in the gingival index, but this was not a statistically significant finding.
Xu, Xianglong; Liu, Lingli; Sharma, Manoj; Zhao, Yong
2015-01-01
Introduction: In 2012 in China, 52.9% of men were reported to smoke while only 2.4% of women smoked. This study explored the smoking-related Knowledge, Attitudes and Practices (KAP) among young adult male smokers. Methods: A cross-sectional study was conducted in four municipal areas of Chongqing using a questionnaire administered to 536 natives young male smokers aged 18–45 years old. Results: The total score of smoking cognition, the total score of smoking attitude and the total score of positive behavior to quit smoking was significantly different among the three groups by education. Besides, 30.97% of male smokers never seriously thought about quitting smoking. Logistic regression analysis found smoking-related knowledge, attitudes, behaviors and sociodemographic factors affect having smoking cessation idea. But no statistically significant correlation was observed between smoking cognition and positive behavior to quit smoking in a sample of higher education. No statistically significant correlation was observed between smoking cognition and positive behavior to quit smoking (Pearson correlation coefficient = 0.03012, p = 0.6811), and also no statistically significant correlation was observed between smoking cognition and positive behavior to quit smoking (Pearson correlation coefficient = 0.08869, p = 0.2364) in the sample of higher education young adult males Conclusions: Young adult males with higher education have a better knowledge of smoking hazards and a more positive attitude toward smoking, however, this knowledge and attitude do not necessarily translate into health behavioral outcomes such as not smoking. Overall the present findings indicate that no statistically significant correlation between the education level and quitting smoking idea exists among young adult male smokers in China. This survey gives a snapshot of the impact of education on smoking-related KAP among young adults male smokers. PMID:25689992
Xu, Xianglong; Liu, Lingli; Sharma, Manoj; Zhao, Yong
2015-02-16
In 2012 in China, 52.9% of men were reported to smoke while only 2.4% of women smoked. This study explored the smoking-related Knowledge, Attitudes and Practices (KAP) among young adult male smokers. A cross-sectional study was conducted in four municipal areas of Chongqing using a questionnaire administered to 536 natives young male smokers aged 18-45 years old. The total score of smoking cognition, the total score of smoking attitude and the total score of positive behavior to quit smoking was significantly different among the three groups by education. Besides, 30.97% of male smokers never seriously thought about quitting smoking. Logistic regression analysis found smoking-related knowledge, attitudes, behaviors and sociodemographic factors affect having smoking cessation idea. But no statistically significant correlation was observed between smoking cognition and positive behavior to quit smoking in a sample of higher education. No statistically significant correlation was observed between smoking cognition and positive behavior to quit smoking (Pearson correlation coefficient = 0.03012, p = 0.6811), and also no statistically significant correlation was observed between smoking cognition and positive behavior to quit smoking (Pearson correlation coefficient = 0.08869, p = 0.2364) in the sample of higher education young adult males Young adult males with higher education have a better knowledge of smoking hazards and a more positive attitude toward smoking, however, this knowledge and attitude do not necessarily translate into health behavioral outcomes such as not smoking. Overall the present findings indicate that no statistically significant correlation between the education level and quitting smoking idea exists among young adult male smokers in China. This survey gives a snapshot of the impact of education on smoking-related KAP among young adults male smokers.
Learning Predictive Statistics: Strategies and Brain Mechanisms.
Wang, Rui; Shen, Yuan; Tino, Peter; Welchman, Andrew E; Kourtzi, Zoe
2017-08-30
When immersed in a new environment, we are challenged to decipher initially incomprehensible streams of sensory information. However, quite rapidly, the brain finds structure and meaning in these incoming signals, helping us to predict and prepare ourselves for future actions. This skill relies on extracting the statistics of event streams in the environment that contain regularities of variable complexity from simple repetitive patterns to complex probabilistic combinations. Here, we test the brain mechanisms that mediate our ability to adapt to the environment's statistics and predict upcoming events. By combining behavioral training and multisession fMRI in human participants (male and female), we track the corticostriatal mechanisms that mediate learning of temporal sequences as they change in structure complexity. We show that learning of predictive structures relates to individual decision strategy; that is, selecting the most probable outcome in a given context (maximizing) versus matching the exact sequence statistics. These strategies engage distinct human brain regions: maximizing engages dorsolateral prefrontal, cingulate, sensory-motor regions, and basal ganglia (dorsal caudate, putamen), whereas matching engages occipitotemporal regions (including the hippocampus) and basal ganglia (ventral caudate). Our findings provide evidence for distinct corticostriatal mechanisms that facilitate our ability to extract behaviorally relevant statistics to make predictions. SIGNIFICANCE STATEMENT Making predictions about future events relies on interpreting streams of information that may initially appear incomprehensible. Past work has studied how humans identify repetitive patterns and associative pairings. However, the natural environment contains regularities that vary in complexity from simple repetition to complex probabilistic combinations. Here, we combine behavior and multisession fMRI to track the brain mechanisms that mediate our ability to adapt to changes in the environment's statistics. We provide evidence for an alternate route for learning complex temporal statistics: extracting the most probable outcome in a given context is implemented by interactions between executive and motor corticostriatal mechanisms compared with visual corticostriatal circuits (including hippocampal cortex) that support learning of the exact temporal statistics. Copyright © 2017 Wang et al.
Seçkin, Selda; Ozgũn, Elmas
2011-01-01
The aim of the study was to investigate the importance of consumption of the epidermis as an additional diagnostic criteria for malignant melanoma and to evaluate its relationship to clinicopathological findings. The age, gender, localization of the lesion and the histopathological parameters such as tumor type, Breslow thickness, ulceration, Clark's level, mitosis/mm2, lymphocytic infiltration were noted in 40 malignant melanoma cases. Consumption of the epidermis was evaluated in tumor sections. Consumption of the epidermis (COE) due to thinning of the epidermis and loss of rete ridges was noted as (+) or (-). Furthermore, COE was compared with clinical and histopathological parameters. The Shapiro Wilk and Logistic Regression tests were used for statistical analysis. The results were accepted as significant if the p value was < 0.05. COE was detected in 60% (24/40) of malignant melanoma cases. A positive correlation was present between COE and head and neck localization (p = 0,698), superficial spreading melanoma (p = 0,341), ulceration (p = 0,097) and brisk lymphocytic infiltration (p = 0,200) but the results were not statistically significant. COE was frequently detected in males but the difference was not statistically significant (p = 0.796). There was no correlation or significant statistical association between COE and age, Breslow thickness, Clark's level or the mitotic index. The detection of COE in most of the patients suggests that COE could be a histopathological criterion in the diagnosis of malignant melanoma. The frequent association between COE and the presence of ulceration could also direct attention to COE as regards prognostic importance.
Corneal biomechanical properties in floppy eyelid syndrome.
Muniesa, MaJesús; Muniesa Royo, MaJesús; March, Ana; March de Ribot, Ana; Sánchez-de-la-Torre, Manuel; Huerva, Valetín; Huerva Escanilla, Valetín; Jurjo, Carmen; Jurjo Campo, Carmen; Barbé, Ferran; Barbé Illa, Ferran
2015-05-01
To determine corneal biomechanical properties in patients with floppy eyelid syndrome (FES) and to compare them with eyes of controls. This case-control study included 208 eyes (72 eyes with FES and 136 without FES) of 107 patients (37 patients with FES and 70 without FES). Patients underwent a complete clinical eye examination that included corneal biomechanical evaluation carried out with the Reichert Ocular Response Analyzer. Corneal hysteresis (CH), corneal resistance factor (CRF), central corneal thickness (CCT), Goldmann-correlated intraocular pressure (IOPg), and corneal-compensated intraocular pressure (IOPcc) were evaluated. Mean CH was significantly lower in patients with FES than in those without FES (9.51 ± 1.56 vs. 11.66 ± 9.11; P < 0.001). These results remained statistically significant after adjusting for age and apnea-hypoapnea index (AHI) (P = 0.028). Mean CRF was 10.02 ± 2.08 in the group of patients with FES and 11.21 ± 5.36 in the group of patients without FES (P = 0.001). Mean IOPcc was 17.7 ± 4.8 in patients with FES and 16.3 ± 4.4 in those without FES (P = 0.036). After adjusting for age and AHI, these differences in CRF and IOPcc were not statistically significant (P = 0.26 and P = 0.87, respectively). No statistically significant difference was found between patients with and without FES for Goldmann-correlated intraocular pressure or CCT. Patients with FES had statistically lower CH values. Our findings suggest that corneal biomechanical properties could be changed in patients with FES, reflecting additional structural changes in FES.
Buchert, Ralph; Wilke, Florian; Chakrabarti, Bhismadev; Martin, Brigitte; Brenner, Winfried; Mester, Janos; Clausen, Malte
2005-10-01
Statistical parametric mapping (SPM) gained increasing acceptance for the voxel-based statistical evaluation of brain positron emission tomography (PET) with the glucose analog 2-[18F]-fluoro-2-deoxy-d-glucose (FDG) in patients with suspected Alzheimer's disease (AD). To increase the sensitivity for detection of local changes, individual differences of total brain FDG uptake are usually compensated for by proportional scaling. However, in cases of extensive hypometabolic areas, proportional scaling overestimates scaled uptake. This may cause significant underestimation of the extent of hypometabolic areas by the statistical test. To detect this problem, the authors tested for hypermetabolism. In patients with no visual evidence of true focal hypermetabolism, significant clusters of hypermetabolism in the presence of extended hypometabolism were interpreted as false-positive findings, indicating relevant overestimation of scaled uptake. In this case, scaled uptake was reduced step by step until there were no more significant clusters of hypermetabolism. In 22 consecutive patients with suspected AD, proportional scaling resulted in relevant overestimation of scaled uptake in 9 patients. Scaled uptake had to be reduced by 11.1% +/- 5.3% in these cases to eliminate the artifacts. Adjusted scaling resulted in extension of existing and appearance of new clusters of hypometabolism. Total volume of the additional voxels with significant hypometabolism depended linearly on the extent of the additional scaling and was 202 +/- 118 mL on average. Adjusted scaling helps to identify characteristic metabolic patterns in patients with suspected AD. It is expected to increase specificity of FDGPET in this group of patients.
Bhomi, K K; Subedi, N; Panta, P P
2017-01-01
International prostate symptom score is a validated questionnaire used to evaluate the lower urinary tract symptoms in benign prostatic hyperplasia. Visual prostate symptom score is a new simplified symptom score with pictograms to evaluate the same. We evaluated the correlation of visual prostate symptom score with international prostate symptom score and uroflowmetry parameters in Nepalese male patients with lower urinary tract symptoms. Male patients aged ≥40 years attending the Urology clinic were enrolled in the study. They were given international prostate symptom score and visual prostate symptom score questionnaires to complete providing assistance whenever needed. Demographic data, examination findings and uroflowmetry parameters were noted. Correlation and regression analysis was used to identify correlation of the two scoring systems and uroflowmetry parameters. Among the 66 patients enrolled, only 10 (15.15%) patients were able to understand English language. There was a statistically significant correlation between total visual prostate symptom score and international prostate symptom score (r= 0.822; P<0.01). The correlations between individual scores of the two scoring systems related to force of urinary stream, frequency, nocturia and quality of life were also statistically significant. There was also a statistically significant correlation of both scores with maximum flow rate and average flow rate. There is a statistically significant correlation of visual prostate symptom score with international prostate symptom score and uroflowmetry parameters. IPSS can be replaced with simple VPSS in evaluation of lower urinary tract symptoms in elderly male patients.
Bacchi, Stephen; Licinio, Julio
2015-06-01
The purpose of this study is to review studies published in English between 1 January 2000 and 16 June 2014, in peer-reviewed journals, that have assessed the prevalence of depression, comparing medical students and non-medical students with a single evaluation method. The databases PubMed, Medline, EMBASE, PsycINFO, and Scopus were searched for eligible articles. Searches used combinations of the Medical Subject Headings medical student and depression. Titles and abstracts were reviewed to determine eligibility before full-text articles were retrieved, which were then also reviewed. Twelve studies met eligibility criteria. Non-medical groups surveyed included dentistry, business, humanities, nursing, pharmacy, and architecture students. One study found statistically significant results suggesting that medical students had a higher prevalence of depression than groups of non-medical students; five studies found statistically significant results indicating that the prevalence of depression in medical students was less than that in groups of non-medical students; four studies found no statistically significant difference, and two studies did not report on the statistical significance of their findings. One study was longitudinal, and 11 studies were cross-sectional. While there are limitations to these comparisons, in the main, the reviewed literature suggests that medical students have similar or lower rates of depression compared to certain groups of non-medical students. A lack of longitudinal studies meant that potential common underlying causes could not be discerned, highlighting the need for further research in this area. The high rates of depression among medical students indicate the continuing need for interventions to reduce depression.
A lower bound on the number of cosmic ray events required to measure source catalogue correlations
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dolci, Marco; Romero-Wolf, Andrew; Wissel, Stephanie, E-mail: marco.dolci@polito.it, E-mail: Andrew.Romero-Wolf@jpl.nasa.gov, E-mail: swissel@calpoly.edu
2016-10-01
Recent analyses of cosmic ray arrival directions have resulted in evidence for a positive correlation with active galactic nuclei positions that has weak significance against an isotropic source distribution. In this paper, we explore the sample size needed to measure a highly statistically significant correlation to a parent source catalogue. We compare several scenarios for the directional scattering of ultra-high energy cosmic rays given our current knowledge of the galactic and intergalactic magnetic fields. We find significant correlations are possible for a sample of >1000 cosmic ray protons with energies above 60 EeV.
Selecting a Classification Ensemble and Detecting Process Drift in an Evolving Data Stream
DOE Office of Scientific and Technical Information (OSTI.GOV)
Heredia-Langner, Alejandro; Rodriguez, Luke R.; Lin, Andy
2015-09-30
We characterize the commercial behavior of a group of companies in a common line of business using a small ensemble of classifiers on a stream of records containing commercial activity information. This approach is able to effectively find a subset of classifiers that can be used to predict company labels with reasonable accuracy. Performance of the ensemble, its error rate under stable conditions, can be characterized using an exponentially weighted moving average (EWMA) statistic. The behavior of the EWMA statistic can be used to monitor a record stream from the commercial network and determine when significant changes have occurred. Resultsmore » indicate that larger classification ensembles may not necessarily be optimal, pointing to the need to search the combinatorial classifier space in a systematic way. Results also show that current and past performance of an ensemble can be used to detect when statistically significant changes in the activity of the network have occurred. The dataset used in this work contains tens of thousands of high level commercial activity records with continuous and categorical variables and hundreds of labels, making classification challenging.« less
Effect of Different Ceramic Crown Preparations on Tooth Structure Loss: An In Vitro Study
NASA Astrophysics Data System (ADS)
Ebrahimpour, Ashkan
Objective: To quantify and compare the amount of tooth-structure reduction following the full-coverage preparations for crown materials of porcelain-fused-to-metal, lithium disilicate glass-ceramic and yttria-stabilized tetragonal zirconia polycrystalline for three tooth morphologies. Methods: Groups of resin teeth of different morphologies were individually weighed to high precision, then prepared following the preparation guidelines. The teeth were re-weighed after preparation and the amount of structural reduction was calculated. Statistical analyses were performed to find out if there was a significant difference among the groups. Results: Amount of tooth reduction for zirconia crown preparations was the lowest and statistically different compared with the other two materials. No statistical significance was found between the amount of reduction for porcelain-fused-to-metal and lithium disilicate glass-ceramic crowns. Conclusion: Within the limitations of this study, more tooth structure can be saved when utilizing zirconia full-coverage restorations compared with lithium disilicate glass-ceramic and porcelain-fused-to-metal crowns in maxillary central incisors, first premolars and first molars.
Lee, Y C; Kwon, O E; Park, J M; Eun, Y G
2018-02-01
To analyse the association between 24-hour multichannel intraluminal impedance-pH (24-h MII-pH) parameters and each item of the reflux finding score (RFS) to determine whether the laryngoscopic findings of the RFS could reflect the characteristics of reflux in patients with laryngopharyngeal reflux (LPR). Prospective cohort study. Tertiary care referral medical centre. Patients complaining of LPR symptoms were evaluated via a 24-hour MII-pH. Among them, 99 patients whose LPR was confirmed via 24-hour MII-pH were enrolled in this study. Correlations between RFS ratings and 24-hour MII-pH parameters were evaluated and compared between patients with or without each laryngoscopic finding used in the RFS. Subglottic oedema had a statistically significant positive correlation with number of non-acid LPR and non-acid full column reflux events. Ventricular obliteration and posterior commissure hypertrophy showed a significant correlation with non-acid exposure time and total reflux exposure time. We also found a significant correlation between granuloma/granulation score and number of acid LPR events. The numbers of non-acid LPR and full column reflux events in patients with subglottic oedema were significantly higher than those without subglottic oedema. Among the laryngoscopic findings used in the RFS, subglottic oedema is specific for non-acid reflux episodes, and granuloma/granulation is specific for acid reflux episodes. © 2017 John Wiley & Sons Ltd.
Urkmez, Ahmet; Yuksel, Ozgur Haki; Uruc, Fatih; Akan, Serkan; Yildirim, Caglar; Sahin, Aytac; Verit, Ayhan
2016-05-01
Prostatitis affects 10-14% of men of all ages and ethnicities. More than 50% of the men experience episodes of prostatitis at one time of their lives. Patients with CP typically have longlasting genitourinary/pelvic pain and obstructive and/or irritative voiding symptoms. Sexual dysfunction and psychological symptoms are frequently added to these symptoms. We also investigated the relationship between sexual functions, and lower urinary system symptoms, and asymptomatic histological prostatitis detected on transrectal ultrasound-guided (TRUS) biopsy performed with the indication of high PSA levels. Sixty cases compliant with the study criteria among patients who underwent prostate biopsies between September 2014 and June 2015 with the indication of higher PSA levels were included in the study. All patients were requested to complete IIEF-5 and IPSS forms one day previously. Based on histological analysis of biopsy materials, the patients were allocated into groups of BPH (simple BPH without histological prostatitis) (n:30) and histological chronic prostatitis (combination of BPH and histological prostatitis) (n:30). Mean age of the cases was 65.73±5.01 (range, 56-75 yrs) years. PSA levels ranged between 4-15 ng/ml. A statistically significant intergroup difference was not found regarding mean age, BMIs, PSA levels, incidence rates of hypertension and coronary artery disease (p>0.05). Prostate volumes of the HCP group were higher than those of the BPH group , with statistically significant differences (p:0.001; p<0.01). Questionnaire forms of the patients included in the study were statistically evaluated, and mean IPSS score of the HCP group was found to be higher when compared with that of the BPH group, with statistically significant differences. (p:0.016; p<0.05). However mean IIEF score of the BPH group was higher than that of the HCP group, with statistically significant differences (p:0.039; p<0.05). These findings suggested the presence of a correlation between chronic inflammation and lower urinary tract symptoms (LUTS). In addition, statistically significant lower IIEF values in patients with histological chronic prostatitis relative to those without suggested negative effects of even asymptomatic inflammation on sexual functions and mechanism of erection.
Emotional Intelligence deficits in schizophrenia: The impact of non-social cognition.
Frajo-Apor, Beatrice; Pardeller, Silvia; Kemmler, Georg; Welte, Anna-Sophia; Hofer, Alex
2016-04-01
Previous studies using the Mayer-Salovey-Caruso Emotional Intelligence Test (MSCEIT) revealed significant performance deficits across all areas of Emotional Intelligence (EI) in schizophrenia patients compared to healthy controls. However, none of these studies has investigated a potential influence of non-social cognition on these findings. 56 schizophrenia outpatients and 84 control subjects were investigated using the MSCEIT and the Brief Assessment of Cognition in Schizophrenia (BACS). Analyses of covariance were performed with adjustment for the BACS composite score and education. To investigate this issue in more detail, a mediation analysis was conducted. Patients showed significantly lower EI and non-social cognition levels compared to healthy controls. After adjustment for BACS composite score and education, only the group difference in the "managing emotions" branch and thus in the "strategic" EI part of the MSCEIT remained statistically significant, whereas for all other MSCEIT branches (perceiving, using, understanding emotions) statistical significance was lost. The mediation analysis revealed that the difference between schizophrenia patients and controls regarding the MSCEIT total score was almost fully attributable to the mediating effect of non-social cognition. Our findings suggest that in schizophrenia patients EI is largely influenced by non-social cognitive functioning. Only the "managing emotions" branch was found to be independent of non-social cognition. Consequently, non-social cognitive performance was mainly responsible for the observed differences in EI between schizophrenia patients and controls. This has to be taken into account when interpreting MSCEIT data in this population. Copyright © 2016 Elsevier B.V. All rights reserved.
Krawczyk, Michał
2015-01-01
In this project I investigate the use and possible misuse of p values in papers published in five (high-ranked) journals in experimental psychology. I use a data set of over 135’000 p values from more than five thousand papers. I inspect (1) the way in which the p values are reported and (2) their distribution. The main findings are following: first, it appears that some authors choose the mode of reporting their results in an arbitrary way. Moreover, they often end up doing it in such a way that makes their findings seem more statistically significant than they really are (which is well known to improve the chances for publication). Specifically, they frequently report p values “just above” significance thresholds directly, whereas other values are reported by means of inequalities (e.g. “p<.1”), they round the p values down more eagerly than up and appear to choose between the significance thresholds and between one- and two-sided tests only after seeing the data. Further, about 9.2% of reported p values are inconsistent with their underlying statistics (e.g. F or t) and it appears that there are “too many” “just significant” values. One interpretation of this is that researchers tend to choose the model or include/discard observations to bring the p value to the right side of the threshold. PMID:26061881
ERIC Educational Resources Information Center
Kadhi, T.; Holley, D.; Rudley, D.; Garrison, P.; Green, T.
2010-01-01
The following report gives the statistical findings of the 2010 Thurgood Marshall School of Law (TMSL) Texas Bar results. This data was pre-existing and was given to the Evaluator by email from the Dean. Then, in-depth statistical analyses were run using the SPSS 17 to address the following questions: 1. What are the statistical descriptors of the…
Capturing 'R&D excellence': indicators, international statistics, and innovative universities.
Tijssen, Robert J W; Winnink, Jos J
2018-01-01
Excellent research may contribute to successful science-based technological innovation. We define 'R&D excellence' in terms of scientific research that has contributed to the development of influential technologies, where 'excellence' refers to the top segment of a statistical distribution based on internationally comparative performance scores. Our measurements are derived from frequency counts of literature references ('citations') from patents to research publications during the last 15 years. The 'D' part in R&D is represented by the top 10% most highly cited 'excellent' patents worldwide. The 'R' part is captured by research articles in international scholarly journals that are cited by these patented technologies. After analyzing millions of citing patents and cited research publications, we find very large differences between countries worldwide in terms of the volume of domestic science contributing to those patented technologies. Where the USA produces the largest numbers of cited research publications (partly because of database biases), Switzerland and Israel outperform the US after correcting for the size of their national science systems. To tease out possible explanatory factors, which may significantly affect or determine these performance differentials, we first studied high-income nations and advanced economies. Here we find that the size of R&D expenditure correlates with the sheer size of cited publications, as does the degree of university research cooperation with domestic firms. When broadening our comparative framework to 70 countries (including many medium-income nations) while correcting for size of national science systems, the important explanatory factors become the availability of human resources and quality of science systems. Focusing on the latter factor, our in-depth analysis of 716 research-intensive universities worldwide reveals several universities with very high scores on our two R&D excellence indicators. Confirming the above macro-level findings, an in-depth study of 27 leading US universities identifies research expenditure size as a prime determinant. Our analytical model and quantitative indicators provides a supplementary perspective to input-oriented statistics based on R&D expenditures. The country-level findings are indicative of significant disparities between national R&D systems. Comparing the performance of individual universities, we observe large differences within national science systems. The top ranking 'innovative' research universities contribute significantly to the development of advanced science-based technologies.
Planck 2015 results. XVI. Isotropy and statistics of the CMB
NASA Astrophysics Data System (ADS)
Planck Collaboration; Ade, P. A. R.; Aghanim, N.; Akrami, Y.; Aluri, P. K.; Arnaud, M.; Ashdown, M.; Aumont, J.; Baccigalupi, C.; Banday, A. J.; Barreiro, R. B.; Bartolo, N.; Basak, S.; Battaner, E.; Benabed, K.; Benoît, A.; Benoit-Lévy, A.; Bernard, J.-P.; Bersanelli, M.; Bielewicz, P.; Bock, J. J.; Bonaldi, A.; Bonavera, L.; Bond, J. R.; Borrill, J.; Bouchet, F. R.; Boulanger, F.; Bucher, M.; Burigana, C.; Butler, R. C.; Calabrese, E.; Cardoso, J.-F.; Casaponsa, B.; Catalano, A.; Challinor, A.; Chamballu, A.; Chiang, H. C.; Christensen, P. R.; Church, S.; Clements, D. L.; Colombi, S.; Colombo, L. P. L.; Combet, C.; Contreras, D.; Couchot, F.; Coulais, A.; Crill, B. P.; Cruz, M.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R. D.; Davis, R. J.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Désert, F.-X.; Diego, J. M.; Dole, H.; Donzelli, S.; Doré, O.; Douspis, M.; Ducout, A.; Dupac, X.; Efstathiou, G.; Elsner, F.; Enßlin, T. A.; Eriksen, H. K.; Fantaye, Y.; Fergusson, J.; Fernandez-Cobos, R.; Finelli, F.; Forni, O.; Frailis, M.; Fraisse, A. A.; Franceschi, E.; Frejsel, A.; Frolov, A.; Galeotta, S.; Galli, S.; Ganga, K.; Gauthier, C.; Ghosh, T.; Giard, M.; Giraud-Héraud, Y.; Gjerløw, E.; González-Nuevo, J.; Górski, K. M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Gudmundsson, J. E.; Hansen, F. K.; Hanson, D.; Harrison, D. L.; Henrot-Versillé, S.; Hernández-Monteagudo, C.; Herranz, D.; Hildebrandt, S. R.; Hivon, E.; Hobson, M.; Holmes, W. A.; Hornstrup, A.; Hovest, W.; Huang, Z.; Huffenberger, K. M.; Hurier, G.; Jaffe, A. H.; Jaffe, T. R.; Jones, W. C.; Juvela, M.; Keihänen, E.; Keskitalo, R.; Kim, J.; Kisner, T. S.; Knoche, J.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lähteenmäki, A.; Lamarre, J.-M.; Lasenby, A.; Lattanzi, M.; Lawrence, C. R.; Leonardi, R.; Lesgourgues, J.; Levrier, F.; Liguori, M.; Lilje, P. B.; Linden-Vørnle, M.; Liu, H.; López-Caniego, M.; Lubin, P. M.; Macías-Pérez, J. F.; Maggio, G.; Maino, D.; Mandolesi, N.; Mangilli, A.; Marinucci, D.; Maris, M.; Martin, P. G.; Martínez-González, E.; Masi, S.; Matarrese, S.; McGehee, P.; Meinhold, P. R.; Melchiorri, A.; Mendes, L.; Mennella, A.; Migliaccio, M.; Mikkelsen, K.; Mitra, S.; Miville-Deschênes, M.-A.; Molinari, D.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Moss, A.; Munshi, D.; Murphy, J. A.; Naselsky, P.; Nati, F.; Natoli, P.; Netterfield, C. B.; Nørgaard-Nielsen, H. U.; Noviello, F.; Novikov, D.; Novikov, I.; Oxborrow, C. A.; Paci, F.; Pagano, L.; Pajot, F.; Pant, N.; Paoletti, D.; Pasian, F.; Patanchon, G.; Pearson, T. J.; Perdereau, O.; Perotto, L.; Perrotta, F.; Pettorino, V.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Pietrobon, D.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Popa, L.; Pratt, G. W.; Prézeau, G.; Prunet, S.; Puget, J.-L.; Rachen, J. P.; Rebolo, R.; Reinecke, M.; Remazeilles, M.; Renault, C.; Renzi, A.; Ristorcelli, I.; Rocha, G.; Rosset, C.; Rossetti, M.; Rotti, A.; Roudier, G.; Rubiño-Martín, J. A.; Rusholme, B.; Sandri, M.; Santos, D.; Savelainen, M.; Savini, G.; Scott, D.; Seiffert, M. D.; Shellard, E. P. S.; Souradeep, T.; Spencer, L. D.; Stolyarov, V.; Stompor, R.; Sudiwala, R.; Sunyaev, R.; Sutton, D.; Suur-Uski, A.-S.; Sygnet, J.-F.; Tauber, J. A.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Trombetti, T.; Tucci, M.; Tuovinen, J.; Valenziano, L.; Valiviita, J.; Van Tent, B.; Vielva, P.; Villa, F.; Wade, L. A.; Wandelt, B. D.; Wehus, I. K.; Yvon, D.; Zacchei, A.; Zibin, J. P.; Zonca, A.
2016-09-01
We test the statistical isotropy and Gaussianity of the cosmic microwave background (CMB) anisotropies using observations made by the Planck satellite. Our results are based mainly on the full Planck mission for temperature, but also include some polarization measurements. In particular, we consider the CMB anisotropy maps derived from the multi-frequency Planck data by several component-separation methods. For the temperature anisotropies, we find excellent agreement between results based on these sky maps over both a very large fraction of the sky and a broad range of angular scales, establishing that potential foreground residuals do not affect our studies. Tests of skewness, kurtosis, multi-normality, N-point functions, and Minkowski functionals indicate consistency with Gaussianity, while a power deficit at large angular scales is manifested in several ways, for example low map variance. The results of a peak statistics analysis are consistent with the expectations of a Gaussian random field. The "Cold Spot" is detected with several methods, including map kurtosis, peak statistics, and mean temperature profile. We thoroughly probe the large-scale dipolar power asymmetry, detecting it with several independent tests, and address the subject of a posteriori correction. Tests of directionality suggest the presence of angular clustering from large to small scales, but at a significance that is dependent on the details of the approach. We perform the first examination of polarization data, finding the morphology of stacked peaks to be consistent with the expectations of statistically isotropic simulations. Where they overlap, these results are consistent with the Planck 2013 analysis based on the nominal mission data and provide our most thorough view of the statistics of the CMB fluctuations to date.
Planck 2015 results: XVI. Isotropy and statistics of the CMB
Ade, P. A. R.; Aghanim, N.; Akrami, Y.; ...
2016-09-20
In this paper, we test the statistical isotropy and Gaussianity of the cosmic microwave background (CMB) anisotropies using observations made by the Planck satellite. Our results are based mainly on the full Planck mission for temperature, but also include some polarization measurements. In particular, we consider the CMB anisotropy maps derived from the multi-frequency Planck data by several component-separation methods. For the temperature anisotropies, we find excellent agreement between results based on these sky maps over both a very large fraction of the sky and a broad range of angular scales, establishing that potential foreground residuals do not affect ourmore » studies. Tests of skewness, kurtosis, multi-normality, N-point functions, and Minkowski functionals indicate consistency with Gaussianity, while a power deficit at large angular scales is manifested in several ways, for example low map variance. The results of a peak statistics analysis are consistent with the expectations of a Gaussian random field. The “Cold Spot” is detected with several methods, including map kurtosis, peak statistics, and mean temperature profile. We thoroughly probe the large-scale dipolar power asymmetry, detecting it with several independent tests, and address the subject of a posteriori correction. Tests of directionality suggest the presence of angular clustering from large to small scales, but at a significance that is dependent on the details of the approach. We perform the first examination of polarization data, finding the morphology of stacked peaks to be consistent with the expectations of statistically isotropic simulations. Finally, where they overlap, these results are consistent with the Planck 2013 analysis based on the nominal mission data and provide our most thorough view of the statistics of the CMB fluctuations to date.« less
Considering whether Medicaid is worth the cost: revisiting the Oregon Health Study.
Muennig, Peter A; Quan, Ryan; Chiuzan, Codruta; Glied, Sherry
2015-05-01
The Oregon Health Study was a groundbreaking experiment in which uninsured participants were randomized to either apply for Medicaid or stay with their current care. The study showed that Medicaid produced numerous important socioeconomic and health benefits but had no statistically significant impact on hypertension, hypercholesterolemia, or diabetes. Medicaid opponents interpreted the findings to mean that Medicaid is not a worthwhile investment. Medicaid proponents viewed the experiment as statistically underpowered and, irrespective of the laboratory values, suggestive that Medicaid is a good investment. We tested these competing claims and, using a sensitive joint test and statistical power analysis, confirmed that the Oregon Health Study did not improve laboratory values. However, we also found that Medicaid is a good value, with a cost of just $62 000 per quality-adjusted life-years gained.
Topology of Neutral Hydrogen within the Small Magellanic Cloud
NASA Astrophysics Data System (ADS)
Chepurnov, A.; Gordon, J.; Lazarian, A.; Stanimirovic, S.
2008-12-01
In this paper, genus statistics have been applied to an H I column density map of the Small Magellanic Cloud in order to study its topology. To learn how topology changes with the scale of the system, we provide topology studies for column density maps at varying resolutions. To evaluate the statistical error of the genus, we randomly reassign the phases of the Fourier modes while keeping the amplitudes. We find that at the smallest scales studied (40 pc <= λ <= 80 pc), the genus shift is negative in all regions, implying a clump topology. At the larger scales (110 pc <= λ <= 250 pc), the topology shift is detected to be negative (a "meatball" topology) in four cases and positive (a "swiss cheese" topology) in two cases. In four regions, there is no statistically significant topology shift at large scales.
Rosset, Saharon; Aharoni, Ehud; Neuvirth, Hani
2014-07-01
Issues of publication bias, lack of replicability, and false discovery have long plagued the genetics community. Proper utilization of public and shared data resources presents an opportunity to ameliorate these problems. We present an approach to public database management that we term Quality Preserving Database (QPD). It enables perpetual use of the database for testing statistical hypotheses while controlling false discovery and avoiding publication bias on the one hand, and maintaining testing power on the other hand. We demonstrate it on a use case of a replication server for GWAS findings, underlining its practical utility. We argue that a shift to using QPD in managing current and future biological databases will significantly enhance the community's ability to make efficient and statistically sound use of the available data resources. © 2014 WILEY PERIODICALS, INC.
Ponirou, Paraskevi; Diomidous, Marianna; Mantas, John; Kalokairinou, Athena; Kalouri, Ourania; Kapadochos, Theodoros; Tzavara, Chara
2014-01-01
The education in First Aid through health education programs can help in promoting the health of the population. Meanwhile, the development of alternative forms of education with emphasis on distance learning implemented with e-learning creates an innovative system of knowledge and skills in different population groups. The main purpose of this research proposal is to investigate the effectiveness of the educational program to candidates educators about knowledge and emergency preparedness at school. The study used the Solomon four group design (2 intervention groups and 2 control groups). Statistical analysis showed significant difference within the four groups. Intervention groups had improved significantly their knowledge showing that the program was effective and that they would eventually deal with a threatening situation with right handlings. There were no statistical significant findings regarding other independent variables (p>0,05).The health education program with the implementation of synchronous distance learning succeeded to enhance the knowledge of candidates educators.
The probability of probability and research truths.
Fatovich, Daniel M; Phillips, Michael
2017-04-01
The foundation of much medical research rests on the statistical significance of the P-value, but we have fallen prey to the seductive certainty of significance. Other scientific disciplines work to a different standard. This may partly explain why medical reversal is an increasing phenomenon, whereby new studies (based on the 0.05 standard) overturn previous significant findings. This has generated a crisis in the rigour of evidence-based medicine, as many people erroneously believe that a P < 0.05 means the treatment effect is clinically important. However, statistics are not facts about the world. Nor should they be based on an arbitrary threshold that arose for historical reasons. This arbitrary threshold encourages an unthinking automatic response that contributes to industry's influence on medical research. Examples from emergency medicine practice illustrate these themes. Study replication needs to be valued as much as discovery. Careful and thoughtful unbiased thinking about the results we do have is undervalued. © 2017 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine.
High-Citation Papers in Space Physics: Examination of Gender, Country, and Paper Characteristics
NASA Astrophysics Data System (ADS)
Moldwin, Mark B.; Liemohn, Michael W.
2018-04-01
The number of citations to a refereed journal article from other refereed journal articles is a measure of its impact. Papers, individuals, journals, departments, and institutions are increasingly judged by the impact they have in their disciplines, and citation counts are now a relatively easy (though not necessarily accurate or straightforward) way of attempting to quantify impact. This study examines papers published in the Journal of Geophysical Research—Space Physics in the year 2012 (n = 705) and analyzes the characteristics of high-citation papers compared to low-citation papers. We find that high-citation papers generally have a large number of authors (>5) and cite significantly more articles in the reference section than low-citation papers. We also examined the gender and country of institution of the first author and found that there is not a statistically significant gender bias, but there are some significant differences in citation statistics between articles based on the country of first-author institution.
The efficacy of adult christian support groups in coping with the death of a significant loved one.
Goodman, Herbert; Stone, Mark H
2009-09-01
Psychologists sometimes minimize important resources such as religion and spiritual beliefs for coping with bereavement. Alienation of therapeutic psychology from religious values contrasts to professional and public interest in religious experience and commitment. A supportive viewpoint has come about partially as a result of recognizing important values which clinicians have found absent in many of their clients. Until spiritual belief systems become integrated into the work of clinicians, clients may not be fully integrative in coping with loss. The key finding of this study was that individuals who participated in Christian and secular support groups showed no statistically significant difference in their mean endorsement of negative criteria on the BHS, and no statistically significant difference for their mean score endorsement of positive criteria on the RCOPE. However, a Christian-oriented approach was no less effective than a psychological-oriented one. In both groups, a spiritual connection to a specific or generalized higher power was frequently identified which clients ascribed to facilitating the management of their coping.
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.
Common pitfalls in statistical analysis: Clinical versus statistical significance
Ranganathan, Priya; Pramesh, C. S.; Buyse, Marc
2015-01-01
In clinical research, study results, which are statistically significant are often interpreted as being clinically important. While statistical significance indicates the reliability of the study results, clinical significance reflects its impact on clinical practice. The third article in this series exploring pitfalls in statistical analysis clarifies the importance of differentiating between statistical significance and clinical significance. PMID:26229754
Gutman, Shawn; Kim, Daniel; Tarafder, Solaiman; Velez, Sergio; Jeong, Julia; Lee, Chang H
2018-02-01
To determine the regionally variant quality of collagen alignment in human TMJ discs and its statistical correlation with viscoelastic properties. For quantitative analysis of the quality of collagen alignment, horizontal sections of human TMJ discs with Pricrosirius Red staining were imaged under circularly polarized microscopy. Mean angle and angular deviation of collagen fibers in each region were analyzed using a well-established automated image-processing for angular gradient. Instantaneous and relaxation moduli of each disc region were measured under stress-relaxation test both in tensile and compression. Then Spearman correlation analysis was performed between the angular deviation and the moduli. To understand the effect of glycosaminoglycans on the correlation, TMJ disc samples were treated by chondroitinase ABC (C-ABC). Our imaging processing analysis showed the region-variant direction of collagen alignment, consistently with previous findings. Interestingly, the quality of collagen alignment, not only the directions, was significantly different in between the regions. The angular deviation of fiber alignment in the anterior and intermediate regions were significantly smaller than the posterior region. Medial and lateral regions showed significantly bigger angular deviation than all the other regions. The regionally variant angular deviation values showed statistically significant correlation with the tensile instantaneous modulus and the relaxation modulus, partially dependent on C-ABC treatment. Our findings suggest the region-variant degree of collagen fiber alignment is likely attributed to the heterogeneous viscoelastic properties of TMJ disc that may have significant implications in development of regenerative therapy for TMJ disc. Copyright © 2017 Elsevier Ltd. All rights reserved.
Evaluating the impact of a school-based health intervention using a randomized field experiment.
Greve, Jane; Heinesen, Eskil
2015-07-01
We conduct an econometric evaluation of a health-promoting programme in primary and lower secondary schools in Denmark. The programme includes health-related measurements of the students, communication of knowledge about health, and support of health-promoting projects for students. Half of the schools in the fourth largest municipality in Denmark were randomly selected into a treatment group implementing the programme, while the remainder served as a control group. We estimate both OLS models using only post-intervention observations and difference in differences (DID) models using also pre-intervention observations. We estimate effects of the initiative on BMI, waist/height ratio, overweight and obesity for the entire sample and by gender and grade. We find no consistent effect of the programme. When we use the entire sample, no estimates are statistically significant at conventional levels, although the point estimates for the effect on BMI, indicating an average reduction in the range of 0.10-0.15 kg/m(2), are consistent with the results in a recent Cochrane review evaluating 55 studies of diet and exercise interventions targeting children; and DID estimates which are marginally significant (at the 10% level) indicate that the intervention reduces the risk of obesity by 1% point. Running separate estimations by gender and grade we find a few statistically significant estimates: OLS estimates indicate that the intervention reduces BMI in females in grade 5 by 0.39 kg/m(2) and reduces the risk of obesity in females in grade 9 by 2.6% points; DID estimates indicate an increase in waist for females in preschool class by 1.2 cm and an increase in the risk of obesity in grade 9 males by 4% points. However, if we corrected for multiple hypotheses testing these estimates would be insignificant. There is no statistically significant correlation between participation in the programme and the number of other health-promoting projects at the schools. Copyright © 2015 Elsevier B.V. All rights reserved.
RRW: repeated random walks on genome-scale protein networks for local cluster discovery
Macropol, Kathy; Can, Tolga; Singh, Ambuj K
2009-01-01
Background We propose an efficient and biologically sensitive algorithm based on repeated random walks (RRW) for discovering functional modules, e.g., complexes and pathways, within large-scale protein networks. Compared to existing cluster identification techniques, RRW implicitly makes use of network topology, edge weights, and long range interactions between proteins. Results We apply the proposed technique on a functional network of yeast genes and accurately identify statistically significant clusters of proteins. We validate the biological significance of the results using known complexes in the MIPS complex catalogue database and well-characterized biological processes. We find that 90% of the created clusters have the majority of their catalogued proteins belonging to the same MIPS complex, and about 80% have the majority of their proteins involved in the same biological process. We compare our method to various other clustering techniques, such as the Markov Clustering Algorithm (MCL), and find a significant improvement in the RRW clusters' precision and accuracy values. Conclusion RRW, which is a technique that exploits the topology of the network, is more precise and robust in finding local clusters. In addition, it has the added flexibility of being able to find multi-functional proteins by allowing overlapping clusters. PMID:19740439
Fernandes, Melissa A; Verstraete, Sofia G; Garnett, Elizabeth A; Heyman, Melvin B
2016-02-01
The aim of the study was to investigate the value of microscopic findings in the classification of pediatric Crohn disease (CD) by determining whether classification of disease changes significantly with inclusion of histologic findings. Sixty patients were randomly selected from a cohort of patients studied at the Pediatric Inflammatory Bowel Disease Clinic at the University of California, San Francisco Benioff Children's Hospital. Two physicians independently reviewed the electronic health records of the included patients to determine the Paris classification for each patient by adhering to present guidelines and then by including microscopic findings. Macroscopic and combined disease location classifications were discordant in 34 (56.6%), with no statistically significant differences between groups. Interobserver agreement was higher in the combined classification (κ = 0.73, 95% confidence interval 0.65-0.82) as opposed to when classification was limited to macroscopic findings (κ = 0.53, 95% confidence interval 0.40-0.58). When evaluating the proximal upper gastrointestinal tract (Paris L4a), the interobserver agreement was better in macroscopic compared with the combined classification. Disease extent classifications differed significantly when comparing isolated macroscopic findings (Paris classification) with the combined scheme that included microscopy. Further studies are needed to determine which scheme provides more accurate representation of disease extent.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gozalo, Alfonso S.; Chavera, Alfonso; Montoya, Enrique J.
2008-02-01
The purpose of this study was to determine serum reference values for crea- tine kinase (CK), aspartate aminotransferase (AST), and lactate dehydroge- nase (LDH) in captive-born and wild-caught owl monkeys to assess their usefulness for diagnosing myocardial disease. Urine samples were also collected and semi-quantitative tests performed. There was no statistically significant difference between CK, AST, and LDH when comparing both groups. However, when comparing monkeys with proteinuria to those without proteinuria, a statistically significant difference in CK value was observed (P = 0.021). In addition, the CK/AST ratio revealed that 29% of the animals included in this study hadmore » values suggesting cardiac infarction. Grossly, cardiac concentric hypertrophy of the left ventricle and small, pitted kidneys were the most common findings. Microscopically, myocardial fibrosis, contraction band necrosis, hypertrophy and hyperplasia of coronary arteries, medium-sized renal arteries, and afferent glomerular arteriolae were the most significant lesions, along with increased mesangial matrix and hypercellularity of glomeruli, Bowman’s capsule, and peritubular space fibroplasia. These findings suggest that CK, AST, and LDH along with urinalysis provide a reliable method for diagnosing cardiomyopathies in the owl monkey. In addition, CK/AST ratio, proteinuria, and the observed histological and ultrastructural changes suggest that Aotus vociferans suffer from arterial hypertension and chronic myocardial infarction.« less
Dermatoglyphics and Karyotype Analysis in Primary Amenorrhoea
Sontakke, Bharat R; Waghmare, Jwalant E; Tarnekar, Aditya M; Shende, Moreshwar R; Pal, Asoke K
2014-01-01
Background: Dermatoglyphics is the scientific study of the skin ridge patterns on the fingers, toes, palms of the hands and soles of feet. Dermatoglyphics is in use as a supportive diagnostic tool in genetic or chromosomal disorders as well as in clinical conditions with genetic etiologies. Primary amenorrhoea and Dermatoglyphics, both have the suspected multifactorial (genetic and environmental) aetiologies. Objective: In the present study the finger dermatoglyphic patterns were studied in primary amenorrhoea cases and age matched fertile control females and also attention was given to find out whether a specific dermatoglyphic trait exists in primary amenorrhoea cases and whether it was statistically significant. Materials and Methods: To study the role of dermatoglyphics in primary amenorrhoea, a study was conducted on 30 subjects with primary amenorrhoea (as cases) and compared it with equal number of age matched fertile females (as controls). We studied fingertip patterns in all the subjects enrolled. Simultaneously we have assessed the Karyotype of primary amenorrhoea cases. Result and Conclusion: Two subjects in experimental group have shown abnormal Karyotypes. The most significant finding in present study was increased total finger ridge count (TFRC) in primary amenorrhoea cases which was statistically significant. We also found higher frequency of loops and arches in primary amenorrhoea with abnormal karyotypes. This type of study may be quite useful as a supportive investigation, in stating the predisposition of an individual to primary amenorrhoea and referral of an individual for karyotyping. PMID:25653930
Sanguebuche, Taissane Rodrigues; Peixe, Bruna Pias; Bruno, Rúbia Soares; Biaggio, Eliara Pinto Vieira; Garcia, Michele Vargas
2018-01-01
Introduction The auditory system consists of sensory structures and central connections. The evaluation of the auditory pathway at a central level can be performed through behavioral and electrophysiological tests, because they are complementary to each other and provide important information about comprehension. Objective To correlate the findings of speech brainstem-evoked response audiometry with the behavioral tests Random Gap Detection Test and Masking Level Difference in adults with hearing loss. Methods All patients were submitted to a basic audiological evaluation, to the aforementioned behavioral tests, and to an electrophysiological assessment, by means of click-evoked and speech-evoked brainstem response audiometry. Results There were no statistically significant values among the electrophysiological test and the behavioral tests. However, there was a significant correlation between the V and A waves, as well as the D and F waves, of the speech-evoked brainstem response audiometry peaks. Such correlations are positive, indicating that the increase of a variable implies an increase in another and vice versa. Conclusion It was possible to correlate the findings of the speech-evoked brainstem response audiometry with those of the behavioral tests Random Gap Detection and Masking Level Difference. However, there was no statistically significant correlation between them. This shows that the electrophysiological evaluation does not depend uniquely on the behavioral skills of temporal resolution and selective attention. PMID:29379574
Statistically significant relational data mining :
DOE Office of Scientific and Technical Information (OSTI.GOV)
Berry, Jonathan W.; Leung, Vitus Joseph; Phillips, Cynthia Ann
This report summarizes the work performed under the project (3z(BStatitically significant relational data mining.(3y (BThe goal of the project was to add more statistical rigor to the fairly ad hoc area of data mining on graphs. Our goal was to develop better algorithms and better ways to evaluate algorithm quality. We concetrated on algorithms for community detection, approximate pattern matching, and graph similarity measures. Approximate pattern matching involves finding an instance of a relatively small pattern, expressed with tolerance, in a large graph of data observed with uncertainty. This report gathers the abstracts and references for the eight refereed publicationsmore » that have appeared as part of this work. We then archive three pieces of research that have not yet been published. The first is theoretical and experimental evidence that a popular statistical measure for comparison of community assignments favors over-resolved communities over approximations to a ground truth. The second are statistically motivated methods for measuring the quality of an approximate match of a small pattern in a large graph. The third is a new probabilistic random graph model. Statisticians favor these models for graph analysis. The new local structure graph model overcomes some of the issues with popular models such as exponential random graph models and latent variable models.« less
Chiavegatto Filho, Alexandre Dias Porto; Kawachi, Ichiro; Wang, Yuan Pang; Viana, Maria Carmen; Andrade, Laura Helena Silveira Guerra
2013-11-01
Test the original income inequality theory, by analysing its association with depression, anxiety and any mental disorders. We analysed a sample of 3542 individuals aged 18 years and older selected through a stratified, multistage area probability sample of households from the São Paulo Metropolitan Area. Mental disorder symptoms were assessed using the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) criteria. Bayesian multilevel logistic models were performed. Living in areas with medium and high-income inequality was statistically associated with increased risk of depression, relative to low-inequality areas (OR 1.76; 95% CI 1.21 to 2.55, and 1.53; 95% CI 1.07 to 2.19, respectively). The same was not true for anxiety (OR 1.25; 95% CI 0.90 to 1.73, and OR 1.07; 95% CI 0.79 to 1.46). In the case of any mental disorder, results were mixed. In general, our findings were consistent with the income inequality theory, that is, people living in places with higher income inequality had an overall higher odd of mental disorders, albeit not always statistically significant. The fact that depression, but not anxiety, was statistically significant could indicate a pathway by which inequality influences health.
Statistical tests for power-law cross-correlated processes
NASA Astrophysics Data System (ADS)
Podobnik, Boris; Jiang, Zhi-Qiang; Zhou, Wei-Xing; Stanley, H. Eugene
2011-12-01
For stationary time series, the cross-covariance and the cross-correlation as functions of time lag n serve to quantify the similarity of two time series. The latter measure is also used to assess whether the cross-correlations are statistically significant. For nonstationary time series, the analogous measures are detrended cross-correlations analysis (DCCA) and the recently proposed detrended cross-correlation coefficient, ρDCCA(T,n), where T is the total length of the time series and n the window size. For ρDCCA(T,n), we numerically calculated the Cauchy inequality -1≤ρDCCA(T,n)≤1. Here we derive -1≤ρDCCA(T,n)≤1 for a standard variance-covariance approach and for a detrending approach. For overlapping windows, we find the range of ρDCCA within which the cross-correlations become statistically significant. For overlapping windows we numerically determine—and for nonoverlapping windows we derive—that the standard deviation of ρDCCA(T,n) tends with increasing T to 1/T. Using ρDCCA(T,n) we show that the Chinese financial market's tendency to follow the U.S. market is extremely weak. We also propose an additional statistical test that can be used to quantify the existence of cross-correlations between two power-law correlated time series.
Finding Statistically Significant Communities in Networks
Lancichinetti, Andrea; Radicchi, Filippo; Ramasco, José J.; Fortunato, Santo
2011-01-01
Community structure is one of the main structural features of networks, revealing both their internal organization and the similarity of their elementary units. Despite the large variety of methods proposed to detect communities in graphs, there is a big need for multi-purpose techniques, able to handle different types of datasets and the subtleties of community structure. In this paper we present OSLOM (Order Statistics Local Optimization Method), the first method capable to detect clusters in networks accounting for edge directions, edge weights, overlapping communities, hierarchies and community dynamics. It is based on the local optimization of a fitness function expressing the statistical significance of clusters with respect to random fluctuations, which is estimated with tools of Extreme and Order Statistics. OSLOM can be used alone or as a refinement procedure of partitions/covers delivered by other techniques. We have also implemented sequential algorithms combining OSLOM with other fast techniques, so that the community structure of very large networks can be uncovered. Our method has a comparable performance as the best existing algorithms on artificial benchmark graphs. Several applications on real networks are shown as well. OSLOM is implemented in a freely available software (http://www.oslom.org), and we believe it will be a valuable tool in the analysis of networks. PMID:21559480
NASA Astrophysics Data System (ADS)
Agus, M.; Hitchcott, P. K.; Penna, M. P.; Peró-Cebollero, M.; Guàrdia-Olmos, J.
2016-11-01
Many studies have investigated the features of probabilistic reasoning developed in relation to different formats of problem presentation, showing that it is affected by various individual and contextual factors. Incomplete understanding of the identity and role of these factors may explain the inconsistent evidence concerning the effect of problem presentation format. Thus, superior performance has sometimes been observed for graphically, rather than verbally, presented problems. The present study was undertaken to address this issue. Psychology undergraduates without any statistical expertise (N = 173 in Italy; N = 118 in Spain; N = 55 in England) were administered statistical problems in two formats (verbal-numerical and graphical-pictorial) under a condition of time pressure. Students also completed additional measures indexing several potentially relevant individual dimensions (statistical ability, statistical anxiety, attitudes towards statistics and confidence). Interestingly, a facilitatory effect of graphical presentation was observed in the Italian and Spanish samples but not in the English one. Significantly, the individual dimensions predicting statistical performance also differed between the samples, highlighting a different role of confidence. Hence, these findings confirm previous observations concerning problem presentation format while simultaneously highlighting the importance of individual dimensions.
Agriculture, population growth, and statistical analysis of the radiocarbon record.
Zahid, H Jabran; Robinson, Erick; Kelly, Robert L
2016-01-26
The human population has grown significantly since the onset of the Holocene about 12,000 y ago. Despite decades of research, the factors determining prehistoric population growth remain uncertain. Here, we examine measurements of the rate of growth of the prehistoric human population based on statistical analysis of the radiocarbon record. We find that, during most of the Holocene, human populations worldwide grew at a long-term annual rate of 0.04%. Statistical analysis of the radiocarbon record shows that transitioning farming societies experienced the same rate of growth as contemporaneous foraging societies. The same rate of growth measured for populations dwelling in a range of environments and practicing a variety of subsistence strategies suggests that the global climate and/or endogenous biological factors, not adaptability to local environment or subsistence practices, regulated the long-term growth of the human population during most of the Holocene. Our results demonstrate that statistical analyses of large ensembles of radiocarbon dates are robust and valuable for quantitatively investigating the demography of prehistoric human populations worldwide.
Golding, Maryanne; Pearce, Wendy; Seymour, John; Cooper, Alison; Ching, Teresa; Dillon, Harvey
2007-02-01
Finding ways to evaluate the success of hearing aid fittings in young infants has increased in importance with the implementation of hearing screening programs. Cortical auditory evoked potentials (CAEP) can be recorded in infants and provides evidence for speech detection at the cortical level. The validity of this technique as a tool of hearing aid evaluation needs, however, to be demonstrated. The present study examined the relationship between the presence/absence of CAEPs to speech stimuli and the outcomes of a parental questionnaire in young infants who were fitted with hearing aids. The presence/absence of responses was determined by an experienced examiner as well as by a statistical measure, Hotelling's T(2). A statistically significant correlation between CAEPs and questionnaire scores was found using the examiner's grading (rs = 0.45) and using the statistical grading (rs = 0.41), and there was reasonably good agreement between traditional response detection methods and the statistical analysis.
Median statistics estimates of Hubble and Newton's constants
NASA Astrophysics Data System (ADS)
Bethapudi, Suryarao; Desai, Shantanu
2017-02-01
Robustness of any statistics depends upon the number of assumptions it makes about the measured data. We point out the advantages of median statistics using toy numerical experiments and demonstrate its robustness, when the number of assumptions we can make about the data are limited. We then apply the median statistics technique to obtain estimates of two constants of nature, Hubble constant (H0) and Newton's gravitational constant ( G , both of which show significant differences between different measurements. For H0, we update the analyses done by Chen and Ratra (2011) and Gott et al. (2001) using 576 measurements. We find after grouping the different results according to their primary type of measurement, the median estimates are given by H0 = 72.5^{+2.5}_{-8} km/sec/Mpc with errors corresponding to 95% c.l. (2 σ) and G=6.674702^{+0.0014}_{-0.0009} × 10^{-11} Nm2kg-2 corresponding to 68% c.l. (1σ).
Temporal and spatial variability of rainfall over Greece
NASA Astrophysics Data System (ADS)
Markonis, Y.; Batelis, S. C.; Dimakos, Y.; Moschou, E.; Koutsoyiannis, D.
2017-10-01
Recent studies have showed that there is a significant decrease in rainfall over Greece during the last half of the pervious century, following an overall decrease of the precipitation at the eastern Mediterranean. However, during the last decade an increase in rainfall was observed in most regions of the country, contrary to the general circulation climate models forecasts. An updated high-resolution dataset of monthly sums and annual daily maxima records derived from 136 stations during the period 1940-2012 allowed us to present some new evidence for the observed change and its statistical significance. The statistical framework used to determine the significance of the slopes in annual rain was not limited to the time independency assumption (Mann-Kendall test), but we also investigated the effect of short- and long-term persistence through Monte Carlo simulation. Our findings show that (a) change occurs in different scales; most regions show a decline since 1950, an increase since 1980 and remain stable during the last 15 years; (b) the significance of the observed decline is highly dependent to the statistical assumptions used; there are indications that the Mann-Kendall test may be the least suitable method; and (c) change in time is strongly linked with the change in space; for scales below 40 years, relatively close regions may develop even opposite trends, while in larger scales change is more uniform.
Lycopene and risk of cardiovascular diseases: A meta-analysis of observational studies.
Song, Bo; Liu, Kai; Gao, Yuan; Zhao, Lu; Fang, Hui; Li, Yusheng; Pei, Lulu; Xu, Yuming
2017-09-01
The aim of current meta-analysis was to investigate the relation between lycopene and risk of cardiovascular diseases (CVD). Studies concerning about the association between lycopene and risk of CVD were searched on Pubmed, Embase, and Web of Science from inception to October 2016. A total of 14 eligible studies were identified. A significantly inverse association with a pooled risk ratio (RR) of 0.83 (95% CI: 0.76-0.90) was shown between lycopene exposure and risk of CVD. Findings were similar restricting to dietary studies (RR = 0.87, 95% CI = 0.79-0.96) and biomarker studies (RR = 0.74, 95% CI = 0. 62-0.87).Dietary lycopene intake was statistically significant for coronary heart disease (CHD) (RR: 0.87; 95% CI: 0.76-0.98) and stroke (RR: 0.83; 95% CI: 0.69-0.96).The pooled risk estimate was generally similar for lycopene biomarker concentrations, but the association was only statistically significant for stroke (RR: 0.65; 95% CI: 0.42-0.87). Subgroup analyses showed that retrospective and low quality studies were statistically significant sources of heterogeneity. Higher lycopene exposure is inversely associated with a lower risk of CVD. Further well-designed randomized clinical trials are required to assess the role of lycopene on CVD. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Gümüş, Pınar; Nizam, Nejat; Nalbantsoy, Ayşe; Özçaka, Özgün; Buduneli, Nurcan
This cross-sectional study aims to evaluate saliva, serum levels of interleukin-21 (IL-21), IL-33, and prostaglandin E2 (PGE2) in patients with generalised chronic periodontitis or aggressive periodontitis. Before initiation of any periodontal treatment, saliva and serum samples were collected and clinical periodontal measurements were recorded from 94 participants (25 aggressive periodontitis patients, 25 chronic periodontitis patients, 44 periodontally healthy individuals). IL-21, IL-33 and PGE2 levels in serum and saliva samples were determined by ELISA. Data were tested statistically using Kruskal-Wallis, Mann-Whitney U-, and Spearman-rho rank tests. Saliva IL-33 levels were statistically significantly higher in the chronic than the aggressive group (p < 0.05). Serum IL-33, saliva and serum IL-21 and PGE2 levels were similar in the two periodontitis groups. Saliva IL-33 levels correlated with age in the chronic periodontitis group (p < 0.05). Statistically significant positive correlations were found between serum, saliva PGE2 levels and plaque index (p < 0.05). IL-33 and IL-21 levels in serum samples positively correlated in the periodontitis groups (p < 0.05). IL-21 and PGE2 analysis did not exhibit discriminating data between generalised chronic and aggressive periodontitis, but the present findings support the role of these cytokines in periodontitis. Statistically significantly higher saliva IL-33 levels in the chronic periodontitis group warrant further research.
Biederman, Joseph; Fitzgerald, Maura; Spencer, Thomas J; Bhide, Pradeep G; McCarthy, Deirdre M; Woodworth, K Yvonne; Saunders, Alexandra; Faraone, Stephen V
2017-02-01
Based on emerging preclinical findings suggesting that paternal smoking at conception may be a risk for ADHD in the offspring, we investigated whether a similar effect can be observed in humans. We analyzed data from an opportunistic dataset of girl probands with ( N = 140) and without ( N = 122) ADHD with available information on paternal smoking at conception. Data were analyzed using Pearson's chi-square tests and multiple logistic regression. ADHD probands had a significantly higher rate of paternal smoking at conception than controls (35% vs. 23%, χ 2 = 3.82, p = .05) with a significant odds ratio of 1.5. However, the association lost significance after controlling for paternal ADHD, most likely due to limited statistical power. While preliminary, findings suggest that paternal smoking at conception may be a risk factor for ADHD in the offspring.
Periodontal disease detection in primary and mixed dentitions.
Nobre, C M Guimarães; Fernandes-Costa, A N; de Melo Soares, M S; Pugliesi, D M Carvalho; de Vasconcelos Gurgel, B C
2016-10-01
This was to compare the periodontal status of children with primary and mixed dentition at the time of their first consultation. Children (200), aged 0-12 years (156 with mixed and 44 with primary dentition), were examined by assessing their simplified plaque index (PI) and simplified periodontal record (PSR). Statistical analysis (Chi-square test) was performed with appropriate software to find any significant associations between sex, type of dentition and PI with the PSR codes (0, 1, 2, 3 and 4). There was no statistically significant difference with regard to gender (p = 0.82). Generalised PI was associated more significantly with mixed dentition (p = 0.025 and higher PSR scores (p < 0.001). There was no significant relationship between sex and PSR codes (p = 0.82). Children presenting with a mixed dentition had worse PI values and PSR scores. It is important to perform periodontal examination in children to diagnose and prevent future periodontal disease and maintain their dentition as well as to identify any associated systemic conditions.
Menon, Sunil K.; Jagtap, Varsha S.; Sarathi, Vijaya; Lila, Anurag R.; Bandgar, Tushar R.; Menon, Padmavathy S; Shah, Nalini S.
2011-01-01
Aims: To study the prevalence of upper airway obstruction (UAO) in “apparently asymptomatic” patients with euthyroid multinodular goitre (MNG) and find correlation between clinical features, UAO on pulmonary function test (PFT) and tracheal narrowing on computerised tomography (CT). Materials and Methods: Consecutive patients with apparently asymptomatic euthyroid MNG attending thyroid clinic in a tertiary centre underwent clinical examination to elicit features of UAO, PFT, and CT of neck and chest. Statistical Analysis Used: Statistical analysis was done with SPSS version 11.5 using paired t-test, Chi square test, and Fisher's exact test. P value of <0.05 was considered to be significant. Results: Fifty-six patients (52 females and four males) were studied. The prevalence of UAO (PFT) and significant tracheal narrowing (CT) was 14.3%. and 9.3%, respectively. Clinical features failed to predict UAO or significant tracheal narrowing. Tracheal narrowing (CT) did not correlate with UAO (PFT). Volume of goitre significantly correlated with degree of tracheal narrowing. Conclusions: Clinical features do not predict UAO on PFT or tracheal narrowing on CT in apparently asymptomatic patients with euthyroid MNG. PMID:21966649
Kritz, Steven; Brown, Lawrence S; Chu, Melissa; John-Hull, Carlota; Madray, Charles; Zavala, Roberto; Louie, Ben
2012-08-01
Electronic medical record (EMR) systems are commonly included in health care reform discussions. However, their embrace by the health care community has been slow. At Addiction Research and Treatment Corporation, an outpatient opioid agonist treatment programme that also provides primary medical care, HIV medical care and case management, substance abuse counselling and vocational services, we studied the implementation of an EMR in the domains of quality, productivity, satisfaction, risk management and financial performance utilizing a prospective pre- and post-implementation study design. This report details the research approach, pre-implementation findings for all five domains, analysis of the pre-implementation findings and some preliminary post-implementation results in the domains of quality and risk management. For quality, there was a highly statistically significant improvement in timely performance of annual medical assessments (P < 0.001) and annual multidiscipline assessments (P < 0.0001). For risk management, the number of events was not sufficient to perform valid statistical analysis. The preliminary findings in the domain of quality are very promising. Should the findings in the other domains prove to be positive, then the impetus to implement EMR in similar health care facilities will be advanced. © 2011 Blackwell Publishing Ltd.
Thermodynamic Modeling of Donor Splice Site Recognition in pre-mRNA
NASA Astrophysics Data System (ADS)
Aalberts, Daniel P.; Garland, Jeffrey A.
2004-03-01
When eukaryotic genes are edited by the spliceosome, the first step in intron recognition is the binding of a U1 snRNA with the donor (5') splice site. We model this interaction thermodynamically to identify splice sites. Applied to a set of 65 annotated genes, our Finding with Binding method achieves a significant separation between real and false sites. Analyzing binding patterns allows us to discard a large number of decoy sites. Our results improve statistics-based methods for donor site recognition, demonstrating the promise of physical modeling to find functional elements in the genome.
Thermodynamic modeling of donor splice site recognition in pre-mRNA
NASA Astrophysics Data System (ADS)
Garland, Jeffrey A.; Aalberts, Daniel P.
2004-04-01
When eukaryotic genes are edited by the spliceosome, the first step in intron recognition is the binding of a U1 small nuclear RNA with the donor ( 5' ) splice site. We model this interaction thermodynamically to identify splice sites. Applied to a set of 65 annotated genes, our “finding with binding” method achieves a significant separation between real and false sites. Analyzing binding patterns allows us to discard a large number of decoy sites. Our results improve statistics-based methods for donor site recognition, demonstrating the promise of physical modeling to find functional elements in the genome.
Kortmann, H R; Wolter, D; Meinecke, F W; Eggers, C
1986-11-01
Sixty-five patients with cervical spine injuries and varied neurological deficits were treated operatively. Evaluation revealed an improvement in neurological findings dependent upon the promptness of anatomical reduction in patients with incomplete lesions. The more frequent neurological improvement seen with open reduction and internal fixation as compared with closed reduction was not statistically significant but was felt to justify the additional resources required for internal fixation. In complete lesions, there was no evidence that the time of anatomical reduction was related to improvement in neurological findings.
Technetium phosphate bone scan in the diagnosis of septic arthritis in childhood
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sundberg, S.B.; Savage, J.P.; Foster, B.K.
1989-09-01
The technetium phosphate bone scans of 106 children with suspected septic arthritis were reviewed to determine whether the bone scan can accurately differentiate septic from nonseptic arthropathy. Only 13% of children with proved septic arthritis had correct blind scan interpretation. The clinically adjusted interpretation did not identify septic arthritis in 30%. Septic arthritis was incorrectly identified in 32% of children with no evidence of septic arthritis. No statistically significant differences were noted between the scan findings in the septic and nonseptic groups and no scan findings correlated specifically with the presence or absence of joint sepsis.
ERIC Educational Resources Information Center
Iman, Jaya Nur
2017-01-01
This research was conducted to find out whether or not using short stories significantly improve the speaking and writing achievements. A quasi-experimental study of non-equivalent pretest-posttest control group design or comparison group design was used in this research. The population of this research was the all first semester undergraduate…
ERIC Educational Resources Information Center
Winneke, Gerhard; Walkowiak, Jens; Kramer, Ursula
2004-01-01
This paper comments on a critical review of cohort studies on PCB-related neurodevelopmental deficit in young children by D.V. Cicchetti, A.S. Kaufman, and S.S. Sparrow (CKS). Major points of criticism of CKS, namely alleged violation of statistical principles, presumed lack of clinical significance of findings, and alleged insufficient control of…
ERIC Educational Resources Information Center
Fredda, Jeffrey V.
In May 2000, the Office of Research and Planning at Nova Southeastern University, Florida, examined student outcomes for courses taught in Internet-based and campus-based formats and found statistically significant differences in student outcomes for courses offered in both modalities. One finding was that graduate students of the Wayne Huizenga…
Efficacy of a mail survey appeal for a dissertation.
Gaski, John F
2004-12-01
Of all the determinants of mail survey response investigated, a dissertation as the purpose is one type of appeal not used in a covering letter. Two parallel field experiments involving populations of wholesale organizations (N=743 and 509) are reported in which such an appeal was tested. Lack of statistically significant findings indicates use of this appeal did not enhance response rate or quality.
ERIC Educational Resources Information Center
Matson, Johnny L.; Hess, Julie A.; Mahan, Sara; Fodstad, Jill C.
2010-01-01
The purpose of this paper was to further establish the validity of the Autism Spectrum Disorder-Diagnostic for Children (ASD-DC). The methodology consisted of testing the similarity of findings between the ASD-DC and the Autism Diagnostic Interview-Revised (ADI-R), which proved to be statistically significant for subscale content scores on social,…
Mitotic activity in dorsal epidermis of Rana pipiens.
NASA Technical Reports Server (NTRS)
Garcia-Arce, H.; Mizell, S.
1972-01-01
Study of statistically significant rhythms of mitotic division in dorsal epidermis of frogs, Rana pipiens, exposed to a 12:12 light:dark environment for 14 days. The results include the findings that (1) male animals have a primary period of 22 hr in summer and 18 hr in winter, (2) female animals have an 18 hr period, and (3) parapinealectomy and blinding abolish the rhythm.
ERIC Educational Resources Information Center
Goldhaber, Dan; Gratz, Trevor; Theobald, Roddy
2016-01-01
We investigate the predictive validity of teacher credential test scores for student performance in secondary STEM classrooms in Washington state. After replicating earlier findings that teacher basic skills licensure test scores are a modest and statistically significant predictor of student math test score gains in elementary grades, we focus on…
ERIC Educational Resources Information Center
Beaver, Kevin M.; Schwartz, Joseph A.; Connolly, Eric J.; Al-Ghamdi, Mohammed Said; Kobeisy, Ahmed Nezar
2015-01-01
The role of parenting in the development of criminal behavior has been the source of a vast amount of research, with the majority of studies detecting statistically significant associations between dimensions of parenting and measures of criminal involvement. An emerging group of scholars, however, has drawn attention to the methodological…
ERIC Educational Resources Information Center
Aldridge, Ashley Elizabeth
2009-01-01
The purpose of this study was to investigate whether any statistically significant differences in mathematics and reading academic achievement and academic gains of male and female students taught in single-sex classes existed when compared to male and female students taught in coeducational classes. This study reported findings from mathematics…
Effect of emergency department CT on neuroimaging case volume and positive scan rates.
Oguz, Kader Karli; Yousem, David M; Deluca, Tom; Herskovits, Edward H; Beauchamp, Norman J
2002-09-01
The authors performed this study to determine the effect a computed tomographic (CT) scanner in the emergency department (ED) has on neuroimaging case volume and positive scan rates. The total numbers of ED visits and neuroradiology CT scans requested from the ED were recorded for 1998 and 2000, the years before and after the installation of a CT unit in the ED. For each examination type (brain, face, cervical spine), studies were graded for major findings (those that affected patient care), minor findings, and normal findings. The CT utilization rates and positive study rates were compared for each type of study performed for both years. There was a statistically significant increase in the utilization rate after installation of the CT unit (P < .001). The fractions of studies with major findings, minor findings, and normal findings changed significantly after installation of the CT unit for facial examinations (P = .002) but not for brain (P = .12) or cervical spine (P = .24) examinations. In all types of studies, the percentage of normal examinations increased. In toto, there was a significant decrease in the positive scan rate after installation of the CT scanner (P = .004). After installation of a CT scanner in the ED, there was increased utilization and a decreased rate of positive neuroradiologic examinations, the latter primarily due to lower positive rates for facial CT scans.
Wollum, Alexandra; Dansereau, Emily; Fullman, Nancy; Achan, Jane; Bannon, Kelsey A; Burstein, Roy; Conner, Ruben O; DeCenso, Brendan; Gasasira, Anne; Haakenstad, Annie; Hanlon, Michael; Ikilezi, Gloria; Kisia, Caroline; Levine, Aubrey J; Masters, Samuel H; Njuguna, Pamela; Okiro, Emelda A; Odeny, Thomas A; Allen Roberts, D; Gakidou, Emmanuela; Duber, Herbert C
2017-08-16
Considerable debate exists concerning the effects of antiretroviral therapy (ART) service scale-up on non-HIV services and overall health system performance in sub-Saharan Africa. In this study, we examined whether ART services affected trends in non-ART outpatient department (OPD) visits in Kenya and Uganda. Using a nationally representative sample of health facilities in Kenya and Uganda, we estimated the effect of ART programs on OPD visits from 2007 to 2012. We modeled the annual percent change in non-ART OPD visits using hierarchical mixed-effects linear regressions, controlling for a range of facility characteristics. We used four different constructs of ART services to capture the different ways in which the presence, growth, overall, and relative size of ART programs may affect non-ART OPD services. Our final sample included 321 health facilities (140 in Kenya and 181 in Uganda). On average, OPD and ART visits increased steadily in Kenya and Uganda between 2007 and 2012. For facilities where ART services were not offered, the average annual increase in OPD visits was 4·2% in Kenya and 13·5% in Uganda. Among facilities that provided ART services, we found average annual OPD volume increases of 7·2% in Kenya and 5·6% in Uganda, with simultaneous annual increases of 13·7% and 12·5% in ART volumes. We did not find a statistically significant relationship between annual changes in OPD services and the presence, growth, overall, or relative size of ART services. However, in a subgroup analysis, we found that Ugandan hospitals that offered ART services had statistically significantly less growth in OPD visits than Ugandan hospitals that did not provide ART services. Our findings suggest that ART services in Kenya and Uganda did not have a statistically significant deleterious effects on OPD services between 2007 and 2012, although subgroup analyses indicate variation by facility type. Our findings are encouraging, particularly given recent recommendations for universal access to ART, demonstrating that expanding ART services is not inherently linked to declines in other health services in sub-Saharan Africa.
NASA Astrophysics Data System (ADS)
Tenenbaum, Joel
This thesis applies statistical physics concepts and methods to quantitatively analyze complex systems. This thesis is separated into four parts: (i) characteristics of earthquake systems (ii) memory and volatility in data time series (iii) the application of part (ii) to world financial markets, and (iv) statistical observations on the evolution of word usage. In Part I, we observe statistical patterns in the occurrence of earthquakes. We select a 14-year earthquake catalog covering the archipelago of Japan. We find that regions traditionally thought of as being too distant from one another for causal contact display remarkably high correlations, and the networks that result have a tendency to link highly connected areas with other highly connected areas. In Part II, we introduce and apply the concept of "volatility asymmetry", the primary use of which is in financial data. We explain the relation between memory and "volatility asymmetry" in terms of an asymmetry parameter lambda. We define a litmus test for determining whether lambda is statistically significant and propose a stochastic model based on this parameter and use the model to further explain empirical data. In Part III, we expand on volatility asymmetry. Importing the concepts of time dependence and universality from physics, we explore the aspects of emerging (or "transition") economies in Eastern Europe as they relate to asymmetry. We find that these emerging markets in some instances behave like developed markets and in other instances do not, and that the distinction is a matter both of country and a matter of time period, crisis periods showing different asymmetry characteristics than "healthy" periods. In Part IV, we take note of a series of findings in econophysics, showing statistical growth similarities between a variety of different areas that all have in common the fact of taking place in areas that are both (i) competing and (ii) dynamic. We show that this same growth distribution can be reproduced in observing the growth rates of the usage of individual words, that just as companies compete for sales in a zero sum marketing game, so do words compete for usage within a limited amount of reader man-hours.
Shahnazi, Mahnaz; Tagavi, Simin; Hajizadeh, Khadije; Farshbaf Khalili, Azize
2013-01-01
Introduction: Preterm premature rupture of membranes (PPROM) can result in fetal complications such as oligohydramnios. This study aimed to determine the effects of intravenous (IV) fluid bolus on amniotic fluid index (AFI) in pregnant women with PPROM. Methods: 24 women with PPROM during singleton live pregnancy of 28 to 34 weeks whose baseline AFI was ≤ 5cm were randomized into two groups. The study group received one liter intravenous fluid bolus of isotonic Ringer serum during 30-minute period. Reevaluations of amniotic fluid index in both groups were made 90 minutes and 48 hours after baseline measurement. Independent t-test and paired t-test were used to compare the two groups and mean amniotic fluid index before and after treatment, respectively. Results: The results of this study demonstrate that AFI decreased statistically significant in both the control and study groups. AFI decreased in both groups at 48 hours later. This decrease was not statistically significant in any group. The mean change in AFI (90 minutes and baseline) and (48 hours and baseline) between the two groups were not significant. The time between mean baseline measurements and delivery were 196.41 and 140.58 hours in the study and control groups, respectively. This difference was not statistically significant. Conclusion: This study did not find significant impact of hydration On AFI as a prophylactic method on oligohydramnios in pregnant women with PPROM. PMID:25276709
Immunohistochemical evaluation of myofibroblast density in odontogenic cysts and tumors.
Kouhsoltani, Maryam; Halimi, Monireh; Jabbari, Golchin
2016-01-01
Background. The aim of this study was to investigate myofibroblast (MF) density in a broad spectrum of odontogenic cysts and tumors and the relation between the density of MFs and the clinical behavior of these lesions. Methods. A total of 105 cases of odontogenic lesions, including unicystic ameloblastoma (UAM), solid ameloblastoma (SA), odontogenic keratocyst (OKC), dentigerous cyst (DC), radicular cyst (RC) (15 for each category), and odontogenic myxoma (OM), adenomatoid odontogenic tumor (AOT), calcifying odontogenic cyst (COC) (10 for each category), were immunohistochemically stained with anti-α-smooth muscle actin antibody. The mean percentage of positive cells in 10 high-power fields was considered as MF density for each case. Results. A statistically significant difference was observed in the mean scores between the study groups (P < 0.001). The intensity of MFs was significantly higher in odontogenic tumors compared to odontogenic cysts (P < 0.001). There was no statistically significant difference between odontogenic tumors, except between UAM and OM (P = 0.041). The difference between OKC and odontogenic tumors was not statistically significant (P > 0.05). The number of MFs was significantly higher in OKC and lower in COC compared to other odontogenic cysts (P = 0.007 and P = 0.045, respectively). Conclusion. The results of the present study suggest a role for MFs in the aggressive behavior of odontogenic lesions. MFs may represent an important target of therapy, especially for aggressive odontogenic lesions. Our findings support the classification of OKC in the category of odontogenic tumors.
Immunohistochemical evaluation of myofibroblast density in odontogenic cysts and tumors
Kouhsoltani, Maryam; Halimi, Monireh; Jabbari, Golchin
2016-01-01
Background. The aim of this study was to investigate myofibroblast (MF) density in a broad spectrum of odontogenic cysts and tumors and the relation between the density of MFs and the clinical behavior of these lesions. Methods. A total of 105 cases of odontogenic lesions, including unicystic ameloblastoma (UAM), solid ameloblastoma (SA), odontogenic keratocyst (OKC), dentigerous cyst (DC), radicular cyst (RC) (15 for each category), and odontogenic myxoma (OM), adenomatoid odontogenic tumor (AOT), calcifying odontogenic cyst (COC) (10 for each category), were immunohistochemically stained with anti-α-smooth muscle actin antibody. The mean percentage of positive cells in 10 high-power fields was considered as MF density for each case. Results. A statistically significant difference was observed in the mean scores between the study groups (P < 0.001). The intensity of MFs was significantly higher in odontogenic tumors compared to odontogenic cysts (P < 0.001). There was no statistically significant difference between odontogenic tumors, except between UAM and OM (P = 0.041). The difference between OKC and odontogenic tumors was not statistically significant (P > 0.05). The number of MFs was significantly higher in OKC and lower in COC compared to other odontogenic cysts (P = 0.007 and P = 0.045, respectively). Conclusion. The results of the present study suggest a role for MFs in the aggressive behavior of odontogenic lesions. MFs may represent an important target of therapy, especially for aggressive odontogenic lesions. Our findings support the classification of OKC in the category of odontogenic tumors. PMID:27092213
Social anxiety and autism spectrum traits among adult FMR1 premutation carriers.
López-Mourelo, O; Mur, E; Madrigal, I; Alvarez-Mora, M I; Gómez-Ansón, B; Pagonabarraga, J; Rodriguez-Revenga, L; Milà, M
2017-01-01
Behavioral symptoms and traits have been proposed as early markers in neurodegenerative diseases. The aim of this study was to evaluate social anxiety and autism in FMR1 premutation carriers using the Social Phobia Inventory (SPIN) and the Autism-Spectrum Quotient (AQ) questionnaires. Fifty-nine premutation carriers were compared with 50 controls. The SPIN test showed statistically significant differences between female but not male carriers. The AQ questionnaire found statistically significant differences between premutation carriers and controls in the total AQ as well as in the social skills and attention switching subdomains. A gender effect was only observed for the social skills subdomain. Spearman's correlation analysis revealed a moderately positive correlation with the total AQ scores as well as the social skills and communication subdomains. Our results show that fragile X-associated tremor/ataxia syndrome (FXTAS) patients have higher AQ scores. Moreover, this is the first study to find statistically significant differences between FXTAS and no-FXTAS premutation carriers in the communication and the imagination subdomains, suggesting that FXTAS patients present a broader autistic phenotype than premutation carriers without FXTAS. Based on our results, a wide range of behavioral/psychiatric traits should be included within the broader phenotypic presentation of individuals with the FMR1 premutation. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Ayahuasca-assisted therapy for addiction: results from a preliminary observational study in Canada.
Thomas, Gerald; Lucas, Philippe; Capler, N Rielle; Tupper, Kenneth W; Martin, Gina
2013-03-01
This paper reports results from a preliminary observational study of ayahuasca-assisted treatment for problematic substance use and stress delivered in a rural First Nations community in British Columbia, Canada. The "Working with Addiction and Stress" retreats combined four days of group counselling with two expert-led ayahuasca ceremonies. This study collected pre-treatment and six months follow-up data from 12 participants on several psychological and behavioral factors related to problematic substance use, and qualitative data assessing the personal experiences of the participants six months after the retreat. Statistically significant (p < 0.05) improvements were demonstrated for scales assessing hopefulness, empowerment, mindfulness, and quality of life meaning and outlook subscales. Self-reported alcohol, tobacco and cocaine use declined, although cannabis and opiate use did not; reported reductions in problematic cocaine use were statistically significant. All study participants reported positive and lasting changes from participating in the retreats. This form of ayahuasca-assisted therapy appears to be associated with statistically significant improvements in several factors related to problematic substance use among a rural aboriginal population. These findings suggest participants may have experienced positive psychological and behavioral changes in response to this therapeutic approach, and that more rigorous research of ayahuasca-assisted therapy for problematic substance use is warranted.
Baldwin Effect and Additional BLR Component in AGN with Superluminal Jets
NASA Astrophysics Data System (ADS)
Patiño Álvarez, Víctor; Torrealba, Janet; Chavushyan, Vahram; Cruz González, Irene; Arshakian, Tigran; León Tavares, Jonathan; Popovic, Luka
2016-06-01
We study the Baldwin Effect (BE) in 96 core-jet blazars with optical and ultraviolet spectroscopic data from a radio-loud AGN sample obtained from the MOJAVE 2cm survey. A statistical analysis is presented of the equivalent widths W_lambda of emission lines H beta 4861, Mg II 2798, C IV 1549, and continuum luminosities at 5100, 3000, and 1350 angstroms. The BE is found statistically significant (with confidence level c.l. > 95%) in H beta and C IV emission lines, while for Mg II the trend is slightly less significant (c.l. = 94.5%). The slopes of the BE in the studied samples for H beta and Mg II are found steeper and with statistically significant difference than those of a comparison radio-quiet sample. We present simulations of the expected BE slopes produced by the contribution to the total continuum of the non-thermal boosted emission from the relativistic jet, and by variability of the continuum components. We find that the slopes of the BE between radio-quiet and radio-loud AGN should not be different, under the assumption that the broad line is only being emitted by the canonical broad line region around the black hole. We discuss that the BE slope steepening in radio AGN is due to a jet associated broad-line region.
Abdul Khader, Nishat Fatima; Dyasanoor, Sujatha
2015-09-01
To assess and compare the salivary flow rate (SFR) and salivary pH among areca nut chewers, oral submucous fibrosis (OSMF) patients and apparently healthy individuals. A comparative study was conducted to assess and compare the SFR and pH among 135 outpatients (45 areca nut chewers + 45 OSMF + 45 control) at The Oxford Dental College and Research Hospital, Bangalore, India. Subjects were interviewed using structural proforma and Modified Schirmer strips and pH paper were implemented for assessing SFR and pH respectively. Statistical analysis was done using IBM SPSS ver. 21.0 software. A statistically significant increase in SFR (35.7 mm at 3rd minutes) among areca nut group and a decrease in SFR among OSMF group (23.4 mm at 3rd minutes) when compared to apparently healthy subjects (30.7 mm at 3rd minutes). The mean pH among areca nut, OSMF and control groups was 6.76, 6.82, and 6.74 respectively with no statistical significance. The observation and findings of the study clearly showed hypersalivation among areca nut group and hyposalivation among OSMF group, with no significant change in salivary pH when compared to healthy subjects.
Terrain stiffness and ankle biomechanics during simulated half-squat parachute landing.
Niu, Wenxin; Fan, Yubo
2013-12-01
A hard surface is potentially one of the risk factors for ankle injuries during parachute landing, but this has never been experimentally validated. This study was designed to evaluate the effects of terrain stiffness on ankle biomechanics during half-squat parachute landing (HSPL). Eight male and eight female healthy participants landed on three surfaces with standard HSPL technique. The three surfaces were cushioned mats with different thicknesses (0 mm, 4 mm, and 8 mm). The effects of terrain hardness and gender and their interaction with ground reaction forces, ankle kinematics, and electromyograms of selected lower-extremity muscles were statistically analyzed with multivariate analysis of variance. The effects of terrain stiffness and the interaction between factors on all variables were not statistically significant. The effects of gender were not statistically significant on most variables. The peak angular velocity of the ankle dorsiflexion was significantly lower in men (mean 1345 degree x s(-1)) than in women (mean 1965 degree x s(-1)). A spongy surface even eliminated the differences between men compared to women in the activity of their tibialis anterior during simulated HSPL. Terrain stiffness, in the ranges tested, did not appear to influence ankle biomechanics among individuals performing HSPL. Additional studies are required to know whether this finding is applicable to realistic parachuting.
Ocular surface culture changes in patients after septoplasty.
Ozkiriş, Mahmut; Kapusuz Gencer, Zeliha; Kader, Ciğdem; Saydam, Levent
2014-01-01
To investigate the interrelationships between pre- and postoperative microbiological changes by taking samples from both eyes of 40 patients who underwent septoplasty due to septal deviation. Forty patients diagnosed with septal deviation who underwent a septoplasty operation under general anesthesia were enrolled in this study. The study was conducted on 40 patients who met the inclusion criteria and attended follow-up visits. One day before the operation and 48 h after the operation, cultures were taken individually from the conjunctivas and puncta of both eyes and sent to the microbiology laboratory. Patients who were candidates for nasal surgery due to their symptoms and clinical examination results were randomly selected and 40 of these completed the study. No statistically significant differences in bacterial growth were observed between the eyes before the operation (P > 0.05). There were, however, statistically significant differences between the eyes in terms of bacterial growth in the postoperative period (P < 0.05). Pathogenic bacterial cultures were grown in 47 eyes in the postoperative period, and this finding was statistically significant. In the eye cultures, the most commonly isolated pathogens were S. epidermidis, and S. aureus. Although the indicated microorganisms isolated from the patient groups were grown in cultures, there were neither clinical symptoms nor signs related to ocular infections.
A change in humidification system can eliminate endotracheal tube occlusion.
Doyle, Alex; Joshi, Manasi; Frank, Peter; Craven, Thomas; Moondi, Parvez; Young, Peter
2011-12-01
Inadequate airway humidification can result in endotracheal tube occlusion. There is evidence that heat and moisture exchangers (HMEs) are more prone to endotracheal tube occlusion than heated humidifiers (HHs) that contain a heated wire circuit. We aimed to compare the incidence of endotracheal tube occlusion while introducing a new dual-heated wire circuit HH in place of an established hydrophobic HME. This was a prospective observational study. All patients who required intubation were included in our analysis. Univariate statistical analysis was performed using a Fisher exact test. P < .05 was considered statistically significant. There were 158 patients in the HME group and 88 patients in the HH group. The incidence of endotracheal tube occlusion was 5.7% in the HME group and 0% in the HH group. Statistical analysis revealed a significant difference between the 2 groups (P = .02). In light of this finding, we changed our practice to provide humidification exclusively by HH. In the subsequent 18-month period, there were no further episodes of endotracheal tube occlusion. Our study demonstrates that there is a significant increase in the incidence of endotracheal tube occlusion when using a hydrophobic HME compared with an HH and that using a dual-heated wire circuit HH can eliminate endotracheal tube occlusion. Copyright © 2011 Elsevier Inc. All rights reserved.
Hadidi, Ahmed; Subotic, Ulrike; Goeppl, Maximilian; Waag, Karl-L
2008-07-01
The aim of this study is to assess the value of early elective cesarean delivery for patients with gastroschisis in comparison with late spontaneous delivery. Analysis of infants with gastroschisis admitted between 1986 and 2006 at a tertiary care center was performed. The findings were analyzed statistically. Eighty-six patients were involved in the study. This included 15 patients who underwent emergency cesarean delivery (EM CD group) because of fetal distress and/or bowel ischemia. The remaining 71 patients born electively were stratified into 4 groups. The early elective cesarean delivery (ECD) group included 23 patients born by ECD before 36 weeks; late vaginal delivery (LVD) group included 23 patients who had LVD after 36 weeks; 24 patients had LCD after 36 weeks because of delayed diagnosis that resulted in late referral; and 1 patient had early spontaneous vaginal delivery (EVD group) before 36 weeks. The mean time to start oral feeding, incidence of complications, and primary closure were significantly better in the ECD group than in the LVD group. The duration of ventilation and the length of stay were shorter in ECD group, but the difference was not statistically significant. Elective cesarean delivery before 36 weeks allows earlier enteral feeding and is associated with less complications and higher incidence of primary closure (statistically significant).
Beckie, T
1989-01-01
The purpose of this study was to investigate the impact of a supportive-educative telephone program on the levels of knowledge and anxiety of patients undergoing coronary artery bypass graft surgery during the first 6 weeks after hospital discharge. With a posttest-only control group design, the first 74 patients scheduled, between September 1986 and February 1987, for coronary artery bypass graft surgery in a large, western Canadian teaching hospital were randomly assigned to either an experimental or a control group. The effect of the intervention, which was implemented by a cardiac rehabilitation nurse specialist, was assessed by a knowledge test and a state anxiety inventory. Data were collected without knowledge of the participants' group assignment. As hypothesized, data analysis with independent t tests revealed a statistically significant (p less than 0.05) difference between the knowledge level of the experimental and the control group in the areas of coronary artery disease, diet, medications, physical activity restrictions, exercise, and rest. A statistically significant difference between the state anxiety level of the experimental and the control group was also evident, as was a statistically significant inverse relationship between participants' knowledge and anxiety levels. From these findings, several implications and recommendations for nursing practice and research have been generated.
Lepesqueur, Laura Soares; de Figueiredo, Viviane Maria Gonçalves; Ferreira, Leandro Lameirão; Sobrinho, Argemiro Soares da Silva; Massi, Marcos; Bottino, Marco Antônio; Nogueira Junior, Lafayette
2015-01-01
To determine the effect of maintaining torque after mechanical cycling of abutment screws that are coated with diamondlike carbon and coated with diamondlike carbon doped with diamond nanoparticles, with external and internal hex connections. Sixty implants were divided into six groups according to the type of connection (external or internal hex) and the type of abutment screw (uncoated, coated with diamondlike carbon, and coated with diamondlike carbon doped with diamond nanoparticles). The implants were inserted into polyurethane resin and crowns of nickel chrome were cemented on the implants. The crowns had a hole for access to the screw. The initial torque and the torque after mechanical cycling were measured. The torque values maintained (in percentages) were evaluated. Statistical analysis was performed using one-way analysis of variance and the Tukey test, with a significance level of 5%. The largest torque value was maintained in uncoated screws with external hex connections, a finding that was statistically significant (P = .0001). No statistically significant differences were seen between the groups with and without coating in maintaining torque for screws with internal hex connections (P = .5476). After mechanical cycling, the diamondlike carbon with and without diamond doping on the abutment screws showed no improvement in maintaining torque in external and internal hex connections.
Demirjian, Louise; Horvath, Frances; Doxsey, Lauri
2018-01-01
A mixed-methods design was used to explore the outcomes of a 6-wk, occupational therapist–led Comfortable Cafeteria program designed to build cafeteria supervisors’ and students’ capacity to create a positive mealtime environment so that all students can successfully participate in and enjoy a healthy meal and socialization with peers. Students whose scores were in the low and mid-range at the outset had statistically significant improvements in pretest–posttest visual analog scale ratings of participation and enjoyment. Cafeteria supervisors demonstrated statistically significant improvements in their perceptions of knowledge and skills to supervise and to encourage healthy eating. Qualitative findings add further insight into the program, suggesting that students learned prosocial values (e.g., being kind, helping others), supervisors actively encouraged positive social interaction, and occupational therapists enjoyed implementing the program and recognized positive supervisor and student changes as a result of integrating services in the cafeteria. PMID:29689174
If You Build (and Moderate) It, They Will Come: The Smokefree Women Facebook Page
2013-01-01
This analysis explores the impact of modifying the Smokefree Women Facebook social media strategy, from primarily promoting resources to encouraging participation in communications about smoking cessation by posting user-generated content. Analyses were performed using data from the Smokefree Women Facebook page to assess the impact of the revised strategy on reach and engagement. Fan engagement increased 430%, and a strong and statistically significant correlation (P < .05) between the frequency of moderator posts and community engagement was observed. The reach of the page also increased by 420%. Our findings indicate that the strategy shift had a statistically significant and positive effect on the frequency of interactions on the Facebook page, providing an example of an approach that may prove useful for reaching and engaging users in online communities. Additional research is needed to assess the association between engagement in virtual communities and health behavior outcomes. PMID:24395993
NASA Astrophysics Data System (ADS)
Grafton, R. Quentin; Ward, Michael B.; To, Hang; Kompas, Tom
2011-08-01
Household survey data for 10 countries are used to quantify and test the importance of price and nonprice factors on residential water demand and investigate complementarities between household water-saving behaviors and the average volumetric price of water. Results show (1) the average volumetric price of water is an important predictor of differences in residential consumption in models that include household characteristics, water-saving devices, attitudinal characteristics and environmental concerns as explanatory variables; (2) of all water-saving devices, only a low volume/dual-flush toilet has a statistically significant and negative effect on water consumption; and (3) environmental concerns have a statistically significant effect on some self-reported water-saving behaviors. While price-based approaches are espoused to promote economic efficiency, our findings stress that volumetric water pricing is also one of the most effective policy levers available to regulate household water consumption.
Public attitudes toward euthanasia and suicide for terminally ill persons: 1977 and 1996.
DeCesare, M A
2000-01-01
This study replicates Singh's (1979) "classic" examination of correlates of euthanasia and suicide attitudes. The purposes of the current study were to assess (1) changes in public attitudes toward these voluntary termination of life practices, and (2) changes in the effects on attitudes of selected independent variables. I found Americans' approval of both euthanasia and suicide in 1996 to be higher than that in 1977. The increase in the approval of suicide, however, far outstripped that of euthanasia. Results of OLS regressions indicated that race, religious commitment, religious attendance, political identification, and suicide approval were statistically significant predictors of euthanasia approval. Only religious attendance and euthanasia approval were statistically significant predictors of suicide approval in both 1977 and 1996. The findings regarding euthanasia approval support those of Singh (1979); those regarding suicide approval do not. Triangulation of methods in future research is necessary to illuminate other aspects of these multifaceted issues.
Massive parallelization of serial inference algorithms for a complex generalized linear model
Suchard, Marc A.; Simpson, Shawn E.; Zorych, Ivan; Ryan, Patrick; Madigan, David
2014-01-01
Following a series of high-profile drug safety disasters in recent years, many countries are redoubling their efforts to ensure the safety of licensed medical products. Large-scale observational databases such as claims databases or electronic health record systems are attracting particular attention in this regard, but present significant methodological and computational concerns. In this paper we show how high-performance statistical computation, including graphics processing units, relatively inexpensive highly parallel computing devices, can enable complex methods in large databases. We focus on optimization and massive parallelization of cyclic coordinate descent approaches to fit a conditioned generalized linear model involving tens of millions of observations and thousands of predictors in a Bayesian context. We find orders-of-magnitude improvement in overall run-time. Coordinate descent approaches are ubiquitous in high-dimensional statistics and the algorithms we propose open up exciting new methodological possibilities with the potential to significantly improve drug safety. PMID:25328363