Understanding the Sampling Distribution and Its Use in Testing Statistical Significance.

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Breunig, Nancy A.

Despite the increasing criticism of statistical significance testing by researchers, particularly in the publication of the 1994 American Psychological Association's style manual, statistical significance test results are still popular in journal articles. For this reason, it remains important to understand the logic of inferential statistics. A…

Swiss solar power statistics 2007 - Significant expansion

International Nuclear Information System (INIS)

Hostettler, T.

2008-01-01

This article presents and discusses the 2007 statistics for solar power in Switzerland. A significant number of new installations is noted as is the high production figures from newer installations. The basics behind the compilation of the Swiss solar power statistics are briefly reviewed and an overview for the period 1989 to 2007 is presented which includes figures on the number of photovoltaic plant in service and installed peak power. Typical production figures in kilowatt-hours (kWh) per installed kilowatt-peak power (kWp) are presented and discussed for installations of various sizes. Increased production after inverter replacement in older installations is noted. Finally, the general political situation in Switzerland as far as solar power is concerned are briefly discussed as are international developments.

On detection and assessment of statistical significance of Genomic Islands

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Chaudhuri Probal

2008-04-01

Full Text Available Abstract Background Many of the available methods for detecting Genomic Islands (GIs in prokaryotic genomes use markers such as transposons, proximal tRNAs, flanking repeats etc., or they use other supervised techniques requiring training datasets. Most of these methods are primarily based on the biases in GC content or codon and amino acid usage of the islands. However, these methods either do not use any formal statistical test of significance or use statistical tests for which the critical values and the P-values are not adequately justified. We propose a method, which is unsupervised in nature and uses Monte-Carlo statistical tests based on randomly selected segments of a chromosome. Such tests are supported by precise statistical distribution theory, and consequently, the resulting P-values are quite reliable for making the decision. Results Our algorithm (named Design-Island, an acronym for Detection of Statistically Significant Genomic Island runs in two phases. Some 'putative GIs' are identified in the first phase, and those are refined into smaller segments containing horizontally acquired genes in the refinement phase. This method is applied to Salmonella typhi CT18 genome leading to the discovery of several new pathogenicity, antibiotic resistance and metabolic islands that were missed by earlier methods. Many of these islands contain mobile genetic elements like phage-mediated genes, transposons, integrase and IS elements confirming their horizontal acquirement. Conclusion The proposed method is based on statistical tests supported by precise distribution theory and reliable P-values along with a technique for visualizing statistically significant islands. The performance of our method is better than many other well known methods in terms of their sensitivity and accuracy, and in terms of specificity, it is comparable to other methods.

[False positive results or what's the probability that a significant P-value indicates a true effect?

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Cucherat, Michel; Laporte, Silvy

2017-09-01

The use of statistical test is central in the clinical trial. At the statistical level, obtaining a Pinformation about the plausibility of the existence of treatment effect. With "Pfalse positive is very high. This is the case if the power is low, if there is an inflation of the alpha risk or if the result is exploratory or chance discoveries. This possibility is important to take into consideration when interpreting the results of clinical trials in order to avoid pushing ahead significant results in appearance, but which are likely to be actually false positive results. Copyright © 2017 Société française de pharmacologie et de thérapeutique. Published by Elsevier Masson SAS. All rights reserved.

Increasing the statistical significance of entanglement detection in experiments.

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Jungnitsch, Bastian; Niekamp, Sönke; Kleinmann, Matthias; Gühne, Otfried; Lu, He; Gao, Wei-Bo; Chen, Yu-Ao; Chen, Zeng-Bing; Pan, Jian-Wei

2010-05-28

Entanglement is often verified by a violation of an inequality like a Bell inequality or an entanglement witness. Considerable effort has been devoted to the optimization of such inequalities in order to obtain a high violation. We demonstrate theoretically and experimentally that such an optimization does not necessarily lead to a better entanglement test, if the statistical error is taken into account. Theoretically, we show for different error models that reducing the violation of an inequality can improve the significance. Experimentally, we observe this phenomenon in a four-photon experiment, testing the Mermin and Ardehali inequality for different levels of noise. Furthermore, we provide a way to develop entanglement tests with high statistical significance.

Testing the Difference of Correlated Agreement Coefficients for Statistical Significance

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Gwet, Kilem L.

2016-01-01

This article addresses the problem of testing the difference between two correlated agreement coefficients for statistical significance. A number of authors have proposed methods for testing the difference between two correlated kappa coefficients, which require either the use of resampling methods or the use of advanced statistical modeling…

Geometric Positioning Accuracy Improvement of ZY-3 Satellite Imagery Based on Statistical Learning Theory

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Niangang Jiao

2018-05-01

Full Text Available With the increasing demand for high-resolution remote sensing images for mapping and monitoring the Earth’s environment, geometric positioning accuracy improvement plays a significant role in the image preprocessing step. Based on the statistical learning theory, we propose a new method to improve the geometric positioning accuracy without ground control points (GCPs. Multi-temporal images from the ZY-3 satellite are tested and the bias-compensated rational function model (RFM is applied as the block adjustment model in our experiment. An easy and stable weight strategy and the fast iterative shrinkage-thresholding (FIST algorithm which is widely used in the field of compressive sensing are improved and utilized to define the normal equation matrix and solve it. Then, the residual errors after traditional block adjustment are acquired and tested with the newly proposed inherent error compensation model based on statistical learning theory. The final results indicate that the geometric positioning accuracy of ZY-3 satellite imagery can be improved greatly with our proposed method.

Statistical Significance for Hierarchical Clustering

Science.gov (United States)

Kimes, Patrick K.; Liu, Yufeng; Hayes, D. Neil; Marron, J. S.

2017-01-01

Summary Cluster analysis has proved to be an invaluable tool for the exploratory and unsupervised analysis of high dimensional datasets. Among methods for clustering, hierarchical approaches have enjoyed substantial popularity in genomics and other fields for their ability to simultaneously uncover multiple layers of clustering structure. A critical and challenging question in cluster analysis is whether the identified clusters represent important underlying structure or are artifacts of natural sampling variation. Few approaches have been proposed for addressing this problem in the context of hierarchical clustering, for which the problem is further complicated by the natural tree structure of the partition, and the multiplicity of tests required to parse the layers of nested clusters. In this paper, we propose a Monte Carlo based approach for testing statistical significance in hierarchical clustering which addresses these issues. The approach is implemented as a sequential testing procedure guaranteeing control of the family-wise error rate. Theoretical justification is provided for our approach, and its power to detect true clustering structure is illustrated through several simulation studies and applications to two cancer gene expression datasets. PMID:28099990

Statistical analysis of RHIC beam position monitors performance

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Calaga, R.; Tomás, R.

2004-04-01

A detailed statistical analysis of beam position monitors (BPM) performance at RHIC is a critical factor in improving regular operations and future runs. Robust identification of malfunctioning BPMs plays an important role in any orbit or turn-by-turn analysis. Singular value decomposition and Fourier transform methods, which have evolved as powerful numerical techniques in signal processing, will aid in such identification from BPM data. This is the first attempt at RHIC to use a large set of data to statistically enhance the capability of these two techniques and determine BPM performance. A comparison from run 2003 data shows striking agreement between the two methods and hence can be used to improve BPM functioning at RHIC and possibly other accelerators.

Statistical analysis of RHIC beam position monitors performance

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R. Calaga

2004-04-01

Full Text Available A detailed statistical analysis of beam position monitors (BPM performance at RHIC is a critical factor in improving regular operations and future runs. Robust identification of malfunctioning BPMs plays an important role in any orbit or turn-by-turn analysis. Singular value decomposition and Fourier transform methods, which have evolved as powerful numerical techniques in signal processing, will aid in such identification from BPM data. This is the first attempt at RHIC to use a large set of data to statistically enhance the capability of these two techniques and determine BPM performance. A comparison from run 2003 data shows striking agreement between the two methods and hence can be used to improve BPM functioning at RHIC and possibly other accelerators.

Statistical significance of trends in monthly heavy precipitation over the US

KAUST Repository

Mahajan, Salil

2011-05-11

Trends in monthly heavy precipitation, defined by a return period of one year, are assessed for statistical significance in observations and Global Climate Model (GCM) simulations over the contiguous United States using Monte Carlo non-parametric and parametric bootstrapping techniques. The results from the two Monte Carlo approaches are found to be similar to each other, and also to the traditional non-parametric Kendall\\'s τ test, implying the robustness of the approach. Two different observational data-sets are employed to test for trends in monthly heavy precipitation and are found to exhibit consistent results. Both data-sets demonstrate upward trends, one of which is found to be statistically significant at the 95% confidence level. Upward trends similar to observations are observed in some climate model simulations of the twentieth century, but their statistical significance is marginal. For projections of the twenty-first century, a statistically significant upwards trend is observed in most of the climate models analyzed. The change in the simulated precipitation variance appears to be more important in the twenty-first century projections than changes in the mean precipitation. Stochastic fluctuations of the climate-system are found to be dominate monthly heavy precipitation as some GCM simulations show a downwards trend even in the twenty-first century projections when the greenhouse gas forcings are strong. © 2011 Springer-Verlag.

Review of the patient positioning reproducibility in head-and-neck radiotherapy using Statistical Process Control.

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Moore, Sarah J; Herst, Patries M; Louwe, Robert J W

2018-05-01

A remarkable improvement in patient positioning was observed after the implementation of various process changes aiming to increase the consistency of patient positioning throughout the radiotherapy treatment chain. However, no tool was available to describe these changes over time in a standardised way. This study reports on the feasibility of Statistical Process Control (SPC) to highlight changes in patient positioning accuracy and facilitate correlation of these changes with the underlying process changes. Metrics were designed to quantify the systematic and random patient deformation as input for the SPC charts. These metrics were based on data obtained from multiple local ROI matches for 191 patients who were treated for head-and-neck cancer during the period 2011-2016. SPC highlighted a significant improvement in patient positioning that coincided with multiple intentional process changes. The observed improvements could be described as a combination of a reduction in outliers and a systematic improvement in the patient positioning accuracy of all patients. SPC is able to track changes in the reproducibility of patient positioning in head-and-neck radiation oncology, and distinguish between systematic and random process changes. Identification of process changes underlying these trends requires additional statistical analysis and seems only possible when the changes do not overlap in time. Copyright © 2018 Elsevier B.V. All rights reserved.

Sibling Competition & Growth Tradeoffs. Biological vs. Statistical Significance.

Science.gov (United States)

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.

Sibling Competition & Growth Tradeoffs. Biological vs. Statistical Significance.

Directory of Open Access Journals (Sweden)

Karen L Kramer

Full Text Available 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.

Increasing the statistical significance of entanglement detection in experiments

Energy Technology Data Exchange (ETDEWEB)

Jungnitsch, Bastian; Niekamp, Soenke; Kleinmann, Matthias; Guehne, Otfried [Institut fuer Quantenoptik und Quanteninformation, Innsbruck (Austria); Lu, He; Gao, Wei-Bo; Chen, Zeng-Bing [Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei (China); Chen, Yu-Ao; Pan, Jian-Wei [Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei (China); Physikalisches Institut, Universitaet Heidelberg (Germany)

2010-07-01

Entanglement is often verified by a violation of an inequality like a Bell inequality or an entanglement witness. Considerable effort has been devoted to the optimization of such inequalities in order to obtain a high violation. We demonstrate theoretically and experimentally that such an optimization does not necessarily lead to a better entanglement test, if the statistical error is taken into account. Theoretically, we show for different error models that reducing the violation of an inequality can improve the significance. We show this to be the case for an error model in which the variance of an observable is interpreted as its error and for the standard error model in photonic experiments. Specifically, we demonstrate that the Mermin inequality yields a Bell test which is statistically more significant than the Ardehali inequality in the case of a photonic four-qubit state that is close to a GHZ state. Experimentally, we observe this phenomenon in a four-photon experiment, testing the above inequalities for different levels of noise.

Reporting effect sizes as a supplement to statistical significance ...

African Journals Online (AJOL)

The purpose of the article is to review the statistical significance reporting practices in reading instruction studies and to provide guidelines for when to calculate and report effect sizes in educational research. A review of six readily accessible (online) and accredited journals publishing research on reading instruction ...

Your Chi-Square Test Is Statistically Significant: Now What?

Science.gov (United States)

Sharpe, Donald

2015-01-01

Applied researchers have employed chi-square tests for more than one hundred years. This paper addresses the question of how one should follow a statistically significant chi-square test result in order to determine the source of that result. Four approaches were evaluated: calculating residuals, comparing cells, ransacking, and partitioning. Data…

Confidence intervals permit, but don't guarantee, better inference than statistical significance testing

Directory of Open Access Journals (Sweden)

Melissa Coulson

2010-07-01

Full Text Available A statistically significant result, and a non-significant result may differ little, although significance status may tempt an interpretation of difference. Two studies are reported that compared interpretation of such results presented using null hypothesis significance testing (NHST, or confidence intervals (CIs. Authors of articles published in psychology, behavioural neuroscience, and medical journals were asked, via email, to interpret two fictitious studies that found similar results, one statistically significant, and the other non-significant. Responses from 330 authors varied greatly, but interpretation was generally poor, whether results were presented as CIs or using NHST. However, when interpreting CIs respondents who mentioned NHST were 60% likely to conclude, unjustifiably, the two results conflicted, whereas those who interpreted CIs without reference to NHST were 95% likely to conclude, justifiably, the two results were consistent. Findings were generally similar for all three disciplines. An email survey of academic psychologists confirmed that CIs elicit better interpretations if NHST is not invoked. Improved statistical inference can result from encouragement of meta-analytic thinking and use of CIs but, for full benefit, such highly desirable statistical reform requires also that researchers interpret CIs without recourse to NHST.

Testing statistical significance scores of sequence comparison methods with structure similarity

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Leunissen Jack AM

2006-10-01

Full Text Available Abstract Background In the past years the Smith-Waterman sequence comparison algorithm has gained popularity due to improved implementations and rapidly increasing computing power. However, the quality and sensitivity of a database search is not only determined by the algorithm but also by the statistical significance testing for an alignment. The e-value is the most commonly used statistical validation method for sequence database searching. The CluSTr database and the Protein World database have been created using an alternative statistical significance test: a Z-score based on Monte-Carlo statistics. Several papers have described the superiority of the Z-score as compared to the e-value, using simulated data. We were interested if this could be validated when applied to existing, evolutionary related protein sequences. Results All experiments are performed on the ASTRAL SCOP database. The Smith-Waterman sequence comparison algorithm with both e-value and Z-score statistics is evaluated, using ROC, CVE and AP measures. The BLAST and FASTA algorithms are used as reference. We find that two out of three Smith-Waterman implementations with e-value are better at predicting structural similarities between proteins than the Smith-Waterman implementation with Z-score. SSEARCH especially has very high scores. Conclusion The compute intensive Z-score does not have a clear advantage over the e-value. The Smith-Waterman implementations give generally better results than their heuristic counterparts. We recommend using the SSEARCH algorithm combined with e-values for pairwise sequence comparisons.

Statistical significance versus clinical relevance.

Science.gov (United States)

van Rijn, Marieke H C; Bech, Anneke; Bouyer, Jean; van den Brand, Jan A J G

2017-04-01

In March this year, the American Statistical Association (ASA) posted a statement on the correct use of P-values, in response to a growing concern that the P-value is commonly misused and misinterpreted. We aim to translate these warnings given by the ASA into a language more easily understood by clinicians and researchers without a deep background in statistics. Moreover, we intend to illustrate the limitations of P-values, even when used and interpreted correctly, and bring more attention to the clinical relevance of study findings using two recently reported studies as examples. We argue that P-values are often misinterpreted. A common mistake is saying that P < 0.05 means that the null hypothesis is false, and P ≥0.05 means that the null hypothesis is true. The correct interpretation of a P-value of 0.05 is that if the null hypothesis were indeed true, a similar or more extreme result would occur 5% of the times upon repeating the study in a similar sample. In other words, the P-value informs about the likelihood of the data given the null hypothesis and not the other way around. A possible alternative related to the P-value is the confidence interval (CI). It provides more information on the magnitude of an effect and the imprecision with which that effect was estimated. However, there is no magic bullet to replace P-values and stop erroneous interpretation of scientific results. Scientists and readers alike should make themselves familiar with the correct, nuanced interpretation of statistical tests, P-values and CIs. © The Author 2017. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.

Statistical significance of epidemiological data. Seminar: Evaluation of epidemiological studies

International Nuclear Information System (INIS)

Weber, K.H.

1993-01-01

In stochastic damages, the numbers of events, e.g. the persons who are affected by or have died of cancer, and thus the relative frequencies (incidence or mortality) are binomially distributed random variables. Their statistical fluctuations can be characterized by confidence intervals. For epidemiologic questions, especially for the analysis of stochastic damages in the low dose range, the following issues are interesting: - Is a sample (a group of persons) with a definite observed damage frequency part of the whole population? - Is an observed frequency difference between two groups of persons random or statistically significant? - Is an observed increase or decrease of the frequencies with increasing dose random or statistically significant and how large is the regression coefficient (= risk coefficient) in this case? These problems can be solved by sttistical tests. So-called distribution-free tests and tests which are not bound to the supposition of normal distribution are of particular interest, such as: - χ 2 -independence test (test in contingency tables); - Fisher-Yates-test; - trend test according to Cochran; - rank correlation test given by Spearman. These tests are explained in terms of selected epidemiologic data, e.g. of leukaemia clusters, of the cancer mortality of the Japanese A-bomb survivors especially in the low dose range as well as on the sample of the cancer mortality in the high background area in Yangjiang (China). (orig.) [de

Statistical Study on Respiratory Stability Through RPM Signal Analysis according to Patient Position Under Radiation Therapy and Device

International Nuclear Information System (INIS)

Park, Myung Hwan; Seo, Jeong Min; Choi, Byeong Gi; Shin, Eun Hyeok; Song, Gi Won

2011-01-01

This study statistically analyzed the difference of the stability of maintaining a respiratory period shown according to position and use of a device to search the tendency and usefulness of a device. The study obtained respiratory signals which maintained a respiratory period for 20 minutes each supine and prone position for 11 subjects. The study obtained respiratory signals in a state of using a belly board for 7 patients in a bad condition of a respiratory period in a prone position to analyze a change in respiration and the stability before and after the use of a device. The supine part showed 54.5%, better than the prone part of 36.4% in a case that the stability for maintaining a respiratory period was in a good condition as a fixed respiratory period was well maintained according to the position. 6 patients (85%) showed a maintenance pattern of a respiratory period significantly different before the use and 4 patients showed a significantly good change in the stability for maintaining a respiratory period as a result that belly boards were used for 7 patients that the maintenance of a respiratory period was not in a good condition on a prone position. It seemed that this study could contribute to the maintenance of respiratory period and of respiratory stability as the optimal position for maintenance of respiration and the use of a device such as a belly board were decided through statistic analysis of respiratory signals and its application even if patient position and use of device were decided by the beam arrangement a treatment part of a patient, location of a target, and an expected plan.

Statistical Significance and Effect Size: Two Sides of a Coin.

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Fan, Xitao

This paper suggests that statistical significance testing and effect size are two sides of the same coin; they complement each other, but do not substitute for one another. Good research practice requires that both should be taken into consideration to make sound quantitative decisions. A Monte Carlo simulation experiment was conducted, and a…

Publication of statistically significant research findings in prosthodontics & implant dentistry in the context of other dental specialties.

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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.

Significant Statistics: Viewed with a Contextual Lens

Science.gov (United States)

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…

Relationship of condylar position to disc position and morphology

Energy Technology Data Exchange (ETDEWEB)

Incesu, L.; Taskaya-Yilmaz, N. E-mail: nergizy@omu.edu.tr; Oeguetcen-Toller, M.; Uzun, E

2004-09-01

Introduction/objective: The purpose of this study was to assess whether condylar position, as depicted by magnetic resonance imaging, was an indicator of disc morphology and position. Methods and material: One hundred and twenty two TMJs of 61 patients with temporomandibular joint disorder were examined. Condylar position, disc deformity and degree of anterior disc displacement were evaluated by using magnetic resonance imaging. Results and discussion: Posterior condyle position was found to be the main feature of temporomandibular joints with slight and moderate anterior disc displacement. No statistical significance was found between the condylar position, and reducing and nonreducing disc positions. On the other hand, superior disc position was found to be statistically significant for centric condylar position. Conclusion: It was concluded that posterior condyle position could indicate anterior disc displacement whereas there was no relation between the position of condyle and the disc deformity.

"What If" Analyses: Ways to Interpret Statistical Significance Test Results Using EXCEL or "R"

Science.gov (United States)

Ozturk, Elif

2012-01-01

The present paper aims to review two motivations to conduct "what if" analyses using Excel and "R" to understand the statistical significance tests through the sample size context. "What if" analyses can be used to teach students what statistical significance tests really do and in applied research either prospectively to estimate what sample size…

Statistical vs. Economic Significance in Economics and Econometrics: Further comments on McCloskey & Ziliak

DEFF Research Database (Denmark)

Engsted, Tom

I comment on the controversy between McCloskey & Ziliak and Hoover & Siegler on statistical versus economic significance, in the March 2008 issue of the Journal of Economic Methodology. I argue that while McCloskey & Ziliak are right in emphasizing 'real error', i.e. non-sampling error that cannot...... be eliminated through specification testing, they fail to acknowledge those areas in economics, e.g. rational expectations macroeconomics and asset pricing, where researchers clearly distinguish between statistical and economic significance and where statistical testing plays a relatively minor role in model...

Significant association between renal function and amyloid-positive area in renal biopsy specimens in AL amyloidosis

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Kuroda Takeshi

2012-09-01

Full Text Available Abstract Background The kidney is a major target organ for systemic amyloidosis that often affects the kidney including proteinura, and elevated serum creatinine (Cr. The correlation between amount of amyloid deposits and clinical parameters is not known. The aim of this study was to clarify correlation the amyloid area in all renal biopsy specimen and clinical parameters. Methods Fifty-eight patients with an established diagnosis of AL amyloidosis participated in the study. All patients showed amyloid deposits in renal biopsies. We retrospectively investigated the correlation between clinical data and amyloid occupied area in whole renal biopsy specimens. Results The area occupied by amyloid was less than 10% in 57 of the 58 patients, and was under 2% in 40. For statistical analyses, %amyloid-positive areas were transformed to common logarithmic values (Log10%amyloid. Cr showed significant correlation with Log10%amyloid and estimated glomerular filtration rate (eGFR showed the significant negative correlation. Patient age, cleatinine clearance (Ccr, blood urea nitorogen, and urinary protein was not significantly correlated with Log10%amyloid. The correlation with other clinical factors such as sex, and serum concentrations of total protein, albumin, immunoglobulins, compliments was evaluated. None of these factors significantly correlated with Log10%amyloid. According to sex- and age- adjusted multiple linear regression analysis, Log10%amyloid had significant positive association with Cr and significant negative association with eGFR. Conclusion There is significant association between amyloid-positive area in renal tissue and renal function, especially Cr and eGFR. The level of Cr and eGFR may be a marker of amount of amyloid in renal tissue.

Prognostic Significance of Progesterone Receptor–Positive Tumor Cells Within Immunohistochemically Defined Luminal A Breast Cancer

Science.gov (United States)

Prat, Aleix; Cheang, Maggie Chon U.; Martín, Miguel; Parker, Joel S.; Carrasco, Eva; Caballero, Rosalía; Tyldesley, Scott; Gelmon, Karen; Bernard, Philip S.; Nielsen, Torsten O.; Perou, Charles M.

2013-01-01

Purpose Current immunohistochemical (IHC)-based definitions of luminal A and B breast cancers are imperfect when compared with multigene expression-based assays. In this study, we sought to improve the IHC subtyping by examining the pathologic and gene expression characteristics of genomically defined luminal A and B subtypes. Patients and Methods Gene expression and pathologic features were collected from primary tumors across five independent cohorts: British Columbia Cancer Agency (BCCA) tamoxifen-treated only, Grupo Español de Investigación en Cáncer de Mama 9906 trial, BCCA no systemic treatment cohort, PAM50 microarray training data set, and a combined publicly available microarray data set. Optimal cutoffs of percentage of progesterone receptor (PR) –positive tumor cells to predict survival were derived and independently tested. Multivariable Cox models were used to test the prognostic significance. Results Clinicopathologic comparisons among luminal A and B subtypes consistently identified higher rates of PR positivity, human epidermal growth factor receptor 2 (HER2) negativity, and histologic grade 1 in luminal A tumors. Quantitative PR gene and protein expression were also found to be significantly higher in luminal A tumors. An empiric cutoff of more than 20% of PR-positive tumor cells was statistically chosen and proved significant for predicting survival differences within IHC-defined luminal A tumors independently of endocrine therapy administration. Finally, no additional prognostic value within hormonal receptor (HR) –positive/HER2-negative disease was observed with the use of the IHC4 score when intrinsic IHC-based subtypes were used that included the more than 20% PR-positive tumor cells and vice versa. Conclusion Semiquantitative IHC expression of PR adds prognostic value within the current IHC-based luminal A definition by improving the identification of good outcome breast cancers. The new proposed IHC-based definition of luminal A

Distinguishing between statistical significance and practical/clinical meaningfulness using statistical inference.

Science.gov (United States)

Wilkinson, Michael

2014-03-01

Decisions about support for predictions of theories in light of data are made using statistical inference. The dominant approach in sport and exercise science is the Neyman-Pearson (N-P) significance-testing approach. When applied correctly it provides a reliable procedure for making dichotomous decisions for accepting or rejecting zero-effect null hypotheses with known and controlled long-run error rates. Type I and type II error rates must be specified in advance and the latter controlled by conducting an a priori sample size calculation. The N-P approach does not provide the probability of hypotheses or indicate the strength of support for hypotheses in light of data, yet many scientists believe it does. Outcomes of analyses allow conclusions only about the existence of non-zero effects, and provide no information about the likely size of true effects or their practical/clinical value. Bayesian inference can show how much support data provide for different hypotheses, and how personal convictions should be altered in light of data, but the approach is complicated by formulating probability distributions about prior subjective estimates of population effects. A pragmatic solution is magnitude-based inference, which allows scientists to estimate the true magnitude of population effects and how likely they are to exceed an effect magnitude of practical/clinical importance, thereby integrating elements of subjective Bayesian-style thinking. While this approach is gaining acceptance, progress might be hastened if scientists appreciate the shortcomings of traditional N-P null hypothesis significance testing.

Statistics Refresher for Molecular Imaging Technologists, Part 2: Accuracy of Interpretation, Significance, and Variance.

Science.gov (United States)

Farrell, Mary Beth

2018-06-01

This article is the second part of a continuing education series reviewing basic statistics that nuclear medicine and molecular imaging technologists should understand. In this article, the statistics for evaluating interpretation accuracy, significance, and variance are discussed. Throughout the article, actual statistics are pulled from the published literature. We begin by explaining 2 methods for quantifying interpretive accuracy: interreader and intrareader reliability. Agreement among readers can be expressed simply as a percentage. However, the Cohen κ-statistic is a more robust measure of agreement that accounts for chance. The higher the κ-statistic is, the higher is the agreement between readers. When 3 or more readers are being compared, the Fleiss κ-statistic is used. Significance testing determines whether the difference between 2 conditions or interventions is meaningful. Statistical significance is usually expressed using a number called a probability ( P ) value. Calculation of P value is beyond the scope of this review. However, knowing how to interpret P values is important for understanding the scientific literature. Generally, a P value of less than 0.05 is considered significant and indicates that the results of the experiment are due to more than just chance. Variance, standard deviation (SD), confidence interval, and standard error (SE) explain the dispersion of data around a mean of a sample drawn from a population. SD is commonly reported in the literature. A small SD indicates that there is not much variation in the sample data. Many biologic measurements fall into what is referred to as a normal distribution taking the shape of a bell curve. In a normal distribution, 68% of the data will fall within 1 SD, 95% will fall within 2 SDs, and 99.7% will fall within 3 SDs. Confidence interval defines the range of possible values within which the population parameter is likely to lie and gives an idea of the precision of the statistic being

Systematic reviews of anesthesiologic interventions reported as statistically significant

DEFF Research Database (Denmark)

Imberger, Georgina; Gluud, Christian; Boylan, John

2015-01-01

statistically significant meta-analyses of anesthesiologic interventions, we used TSA to estimate power and imprecision in the context of sparse data and repeated updates. METHODS: We conducted a search to identify all systematic reviews with meta-analyses that investigated an intervention that may......: From 11,870 titles, we found 682 systematic reviews that investigated anesthesiologic interventions. In the 50 sampled meta-analyses, the median number of trials included was 8 (interquartile range [IQR], 5-14), the median number of participants was 964 (IQR, 523-1736), and the median number...

Visual Statistical Learning Works after Binding the Temporal Sequences of Shapes and Spatial Positions

Directory of Open Access Journals (Sweden)

Osamu Watanabe

2011-05-01

Full Text Available The human visual system can acquire the statistical structures in temporal sequences of object feature changes, such as changes in shape, color, and its combination. Here we investigate whether the statistical learning for spatial position and shape changes operates separately or not. It is known that the visual system processes these two types of information separately; the spatial information is processed in the parietal cortex, whereas object shapes and colors are detected in the temporal pathway, and, after that, we perceive bound information in the two streams. We examined whether the statistical learning operates before or after binding the shape and the spatial information by using the “re-paired triplet” paradigm proposed by Turk-Browne, Isola, Scholl, and Treat (2008. The result showed that observers acquired combined sequences of shape and position changes, but no statistical information in individual sequence was obtained. This finding suggests that the visual statistical learning works after binding the temporal sequences of shapes and spatial structures and would operate in the higher-order visual system; this is consistent with recent ERP (Abla & Okanoya, 2009 and fMRI (Turk-Browne, Scholl, Chun, & Johnson, 2009 studies.

Using the Bootstrap Method for a Statistical Significance Test of Differences between Summary Histograms

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Xu, Kuan-Man

2006-01-01

A new method is proposed to compare statistical differences between summary histograms, which are the histograms summed over a large ensemble of individual histograms. It consists of choosing a distance statistic for measuring the difference between summary histograms and using a bootstrap procedure to calculate the statistical significance level. Bootstrapping is an approach to statistical inference that makes few assumptions about the underlying probability distribution that describes the data. Three distance statistics are compared in this study. They are the Euclidean distance, the Jeffries-Matusita distance and the Kuiper distance. The data used in testing the bootstrap method are satellite measurements of cloud systems called cloud objects. Each cloud object is defined as a contiguous region/patch composed of individual footprints or fields of view. A histogram of measured values over footprints is generated for each parameter of each cloud object and then summary histograms are accumulated over all individual histograms in a given cloud-object size category. The results of statistical hypothesis tests using all three distances as test statistics are generally similar, indicating the validity of the proposed method. The Euclidean distance is determined to be most suitable after comparing the statistical tests of several parameters with distinct probability distributions among three cloud-object size categories. Impacts on the statistical significance levels resulting from differences in the total lengths of satellite footprint data between two size categories are also discussed.

P-Value, a true test of statistical significance? a cautionary note ...

African Journals Online (AJOL)

While it's not the intention of the founders of significance testing and hypothesis testing to have the two ideas intertwined as if they are complementary, the inconvenient marriage of the two practices into one coherent, convenient, incontrovertible and misinterpreted practice has dotted our standard statistics textbooks and ...

Interpreting Statistical Significance Test Results: A Proposed New "What If" Method.

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Kieffer, Kevin M.; Thompson, Bruce

As the 1994 publication manual of the American Psychological Association emphasized, "p" values are affected by sample size. As a result, it can be helpful to interpret the results of statistical significant tests in a sample size context by conducting so-called "what if" analyses. However, these methods can be inaccurate…

Measuring individual significant change on the Beck Depression Inventory-II through IRT-based statistics.

NARCIS (Netherlands)

Brouwer, D.; Meijer, R.R.; Zevalkink, D.J.

2013-01-01

Several researchers have emphasized that item response theory (IRT)-based methods should be preferred over classical approaches in measuring change for individual patients. In the present study we discuss and evaluate the use of IRT-based statistics to measure statistical significant individual

Strategies for Testing Statistical and Practical Significance in Detecting DIF with Logistic Regression Models

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Fidalgo, Angel M.; Alavi, Seyed Mohammad; Amirian, Seyed Mohammad Reza

2014-01-01

This study examines three controversial aspects in differential item functioning (DIF) detection by logistic regression (LR) models: first, the relative effectiveness of different analytical strategies for detecting DIF; second, the suitability of the Wald statistic for determining the statistical significance of the parameters of interest; and…

Simulation of statistical systems with not necessarily real and positive probabilities

International Nuclear Information System (INIS)

Kalkreuter, T.

1991-01-01

A new method to determine expectation values of observables in statistical systems with not necessarily real and positive probabilities is proposed. It is tested in a numerical study of the two-dimensional O(3)-symmetric nonlinear σ-model with Symanzik's one-loop improved lattice action. This model is simulated as polymer system with field dependent activities which can be made positive definite or indefinite by adjusting additive constants of the action. For a system with indefinite activities the new proposal is found to work. It is also verified that local observables are not affected by far-away ploymers with indefinite activities when the system has no long-range order. (orig.)

Thresholds for statistical and clinical significance in systematic reviews with meta-analytic methods

DEFF Research Database (Denmark)

Jakobsen, Janus Christian; Wetterslev, Jorn; Winkel, Per

2014-01-01

BACKGROUND: Thresholds for statistical significance when assessing meta-analysis results are being insufficiently demonstrated by traditional 95% confidence intervals and P-values. Assessment of intervention effects in systematic reviews with meta-analysis deserves greater rigour. METHODS......: Methodologies for assessing statistical and clinical significance of intervention effects in systematic reviews were considered. Balancing simplicity and comprehensiveness, an operational procedure was developed, based mainly on The Cochrane Collaboration methodology and the Grading of Recommendations...... Assessment, Development, and Evaluation (GRADE) guidelines. RESULTS: We propose an eight-step procedure for better validation of meta-analytic results in systematic reviews (1) Obtain the 95% confidence intervals and the P-values from both fixed-effect and random-effects meta-analyses and report the most...

Intensive inpatient treatment for bulimia nervosa: Statistical and clinical significance of symptom changes.

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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.

Recent Literature on Whether Statistical Significance Tests Should or Should Not Be Banned.

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Deegear, James

This paper summarizes the literature regarding statistical significant testing with an emphasis on recent literature in various discipline and literature exploring why researchers have demonstrably failed to be influenced by the American Psychological Association publication manual's encouragement to report effect sizes. Also considered are…

The Health Significance of Positive Emotions in Adulthood and Later Life.

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Ong, Anthony D; Mroczek, Daniel K; Riffin, Catherine

2011-08-01

A growing body of literature supports a link between positive emotions and health in older adults. In this article, we review evidence of the effects of positive emotions on downstream biological processes and meaningful clinical endpoints, such as adult morbidity and mortality. We then present relevant predictions from lifespan theories that suggest changes in cognition and motivation may play an important role in explaining how positive emotions are well maintained in old age, despite pervasive declines in cognitive processes. We conclude by discussing how the application of psychological theory can inform greater understanding of the adaptive significance of positive emotions in adulthood and later life.

Cloud-based solution to identify statistically significant MS peaks differentiating sample categories.

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Ji, Jun; Ling, Jeffrey; Jiang, Helen; Wen, Qiaojun; Whitin, John C; Tian, Lu; Cohen, Harvey J; Ling, Xuefeng B

2013-03-23

Mass spectrometry (MS) has evolved to become the primary high throughput tool for proteomics based biomarker discovery. Until now, multiple challenges in protein MS data analysis remain: large-scale and complex data set management; MS peak identification, indexing; and high dimensional peak differential analysis with the concurrent statistical tests based false discovery rate (FDR). "Turnkey" solutions are needed for biomarker investigations to rapidly process MS data sets to identify statistically significant peaks for subsequent validation. Here we present an efficient and effective solution, which provides experimental biologists easy access to "cloud" computing capabilities to analyze MS data. The web portal can be accessed at http://transmed.stanford.edu/ssa/. Presented web application supplies large scale MS data online uploading and analysis with a simple user interface. This bioinformatic tool will facilitate the discovery of the potential protein biomarkers using MS.

Addendum to the article: Misuse of null hypothesis significance testing: Would estimation of positive and negative predictive values improve certainty of chemical risk assessment?

Science.gov (United States)

Bundschuh, Mirco; Newman, Michael C; Zubrod, Jochen P; Seitz, Frank; Rosenfeldt, Ricki R; Schulz, Ralf

2015-03-01

We argued recently that the positive predictive value (PPV) and the negative predictive value (NPV) are valuable metrics to include during null hypothesis significance testing: They inform the researcher about the probability of statistically significant and non-significant test outcomes actually being true. Although commonly misunderstood, a reported p value estimates only the probability of obtaining the results or more extreme results if the null hypothesis of no effect was true. Calculations of the more informative PPV and NPV require a priori estimate of the probability (R). The present document discusses challenges of estimating R.

Power, effects, confidence, and significance: an investigation of statistical practices in nursing research.

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Gaskin, Cadeyrn J; Happell, Brenda

2014-05-01

improvement. Most importantly, researchers should abandon the misleading practice of interpreting the results from inferential tests based solely on whether they are statistically significant (or not) and, instead, focus on reporting and interpreting effect sizes, confidence intervals, and significance levels. Nursing researchers also need to conduct and report a priori power analyses, and to address the issue of Type I experiment-wise error inflation in their studies. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Determining coding CpG islands by identifying regions significant for pattern statistics on Markov chains.

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Singer, Meromit; Engström, Alexander; Schönhuth, Alexander; Pachter, Lior

2011-09-23

Recent experimental and computational work confirms that CpGs can be unmethylated inside coding exons, thereby showing that codons may be subjected to both genomic and epigenomic constraint. It is therefore of interest to identify coding CpG islands (CCGIs) that are regions inside exons enriched for CpGs. The difficulty in identifying such islands is that coding exons exhibit sequence biases determined by codon usage and constraints that must be taken into account. We present a method for finding CCGIs that showcases a novel approach we have developed for identifying regions of interest that are significant (with respect to a Markov chain) for the counts of any pattern. Our method begins with the exact computation of tail probabilities for the number of CpGs in all regions contained in coding exons, and then applies a greedy algorithm for selecting islands from among the regions. We show that the greedy algorithm provably optimizes a biologically motivated criterion for selecting islands while controlling the false discovery rate. We applied this approach to the human genome (hg18) and annotated CpG islands in coding exons. The statistical criterion we apply to evaluating islands reduces the number of false positives in existing annotations, while our approach to defining islands reveals significant numbers of undiscovered CCGIs in coding exons. Many of these appear to be examples of functional epigenetic specialization in coding exons.

[Comment on] Statistical discrimination

Science.gov (United States)

Chinn, Douglas

In the December 8, 1981, issue of Eos, a news item reported the conclusion of a National Research Council study that sexual discrimination against women with Ph.D.'s exists in the field of geophysics. Basically, the item reported that even when allowances are made for motherhood the percentage of female Ph.D.'s holding high university and corporate positions is significantly lower than the percentage of male Ph.D.'s holding the same types of positions. The sexual discrimination conclusion, based only on these statistics, assumes that there are no basic psychological differences between men and women that might cause different populations in the employment group studied. Therefore, the reasoning goes, after taking into account possible effects from differences related to anatomy, such as women stopping their careers in order to bear and raise children, the statistical distributions of positions held by male and female Ph.D.'s ought to be very similar to one another. Any significant differences between the distributions must be caused primarily by sexual discrimination.

Effect of the left lateral recumbent position compared with the supine and upright positions on placental blood flow in normal late pregnancy.

Science.gov (United States)

Suonio, S; Simpanen, A L; Olkkonen, H; Haring, P

1976-02-01

The placental blood flow was assessed by the 99mTc accumulation method in 10 normal pregnancies in the left lateral recumbent position accomplished by a 15 degree wedge and in the supine position. The postural change caused a 17% decrease in the mean placental accumulation rate, which was not statistically significant. Ten patients were moved from the left lateral recumbent position to the upright position, which caused a statistically significant 23% decrease in the mean accumulation rate. Other haemodynamic variables studied were the maternal heart rate and the systolic and diastolic blood pressures. The clinical significance of the haemodynamic changes produced by alterations in posture are briefly discussed.

A critical discussion of null hypothesis significance testing and statistical power analysis within psychological research

DEFF Research Database (Denmark)

Jones, Allan; Sommerlund, Bo

2007-01-01

The uses of null hypothesis significance testing (NHST) and statistical power analysis within psychological research are critically discussed. The article looks at the problems of relying solely on NHST when dealing with small and large sample sizes. The use of power-analysis in estimating...... the potential error introduced by small and large samples is advocated. Power analysis is not recommended as a replacement to NHST but as an additional source of information about the phenomena under investigation. Moreover, the importance of conceptual analysis in relation to statistical analysis of hypothesis...

Statistical significance estimation of a signal within the GooFit framework on GPUs

Directory of Open Access Journals (Sweden)

Cristella Leonardo

2017-01-01

Full Text Available In order to test the computing capabilities of GPUs with respect to traditional CPU cores a high-statistics toy Monte Carlo technique has been implemented both in ROOT/RooFit and GooFit frameworks with the purpose to estimate the statistical significance of the structure observed by CMS close to the kinematical boundary of the J/ψϕ invariant mass in the three-body decay B+ → J/ψϕK+. GooFit is a data analysis open tool under development that interfaces ROOT/RooFit to CUDA platform on nVidia GPU. The optimized GooFit application running on GPUs hosted by servers in the Bari Tier2 provides striking speed-up performances with respect to the RooFit application parallelised on multiple CPUs by means of PROOF-Lite tool. The considerable resulting speed-up, evident when comparing concurrent GooFit processes allowed by CUDA Multi Process Service and a RooFit/PROOF-Lite process with multiple CPU workers, is presented and discussed in detail. By means of GooFit it has also been possible to explore the behaviour of a likelihood ratio test statistic in different situations in which the Wilks Theorem may or may not apply because its regularity conditions are not satisfied.

Reporting instructions significantly impact false positive rates when reading chest radiographs

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Robinson, John W.; Brennan, Patrick C.; Mello-Thoms, Claudia; Lewis, Sarah J. [The University of Sydney, Medical Image Optimisation and Perception Group, Discipline of Medical Radiation Sciences, Faculty of Health Sciences, Lidcombe, NSW (Australia)

2016-10-15

To determine the impact of specific reporting tasks on the performance of radiologists when reading chest radiographs. Ten experienced radiologists read a set of 40 postero-anterior (PA) chest radiographs: 21 nodule free and 19 with a proven solitary nodule. There were two reporting conditions: an unframed task (UFT) to report any abnormality and a framed task (FT) reporting only lung nodule/s. Jackknife free-response operating characteristic (JAFROC) figure of merit (FOM), specificity, location sensitivity and number of true positive (TP), false positive (FP), true negative (TN) and false negative (FN) decisions were used for analysis. JAFROC FOM for tasks showed a significant reduction in performance for framed tasks (P = 0.006) and an associated decrease in specificity (P = 0.011) but no alteration to the location sensitivity score. There was a significant increase in number of FP decisions made during framed versus unframed tasks for nodule-containing (P = 0.005) and nodule-free (P = 0.011) chest radiographs. No significant differences in TP were recorded. Radiologists report more FP decisions when given specific reporting instructions to search for nodules on chest radiographs. The relevance of clinical history supplied to radiologists is called into question and may induce a negative effect. (orig.)

Reporting instructions significantly impact false positive rates when reading chest radiographs

International Nuclear Information System (INIS)

Robinson, John W.; Brennan, Patrick C.; Mello-Thoms, Claudia; Lewis, Sarah J.

2016-01-01

To determine the impact of specific reporting tasks on the performance of radiologists when reading chest radiographs. Ten experienced radiologists read a set of 40 postero-anterior (PA) chest radiographs: 21 nodule free and 19 with a proven solitary nodule. There were two reporting conditions: an unframed task (UFT) to report any abnormality and a framed task (FT) reporting only lung nodule/s. Jackknife free-response operating characteristic (JAFROC) figure of merit (FOM), specificity, location sensitivity and number of true positive (TP), false positive (FP), true negative (TN) and false negative (FN) decisions were used for analysis. JAFROC FOM for tasks showed a significant reduction in performance for framed tasks (P = 0.006) and an associated decrease in specificity (P = 0.011) but no alteration to the location sensitivity score. There was a significant increase in number of FP decisions made during framed versus unframed tasks for nodule-containing (P = 0.005) and nodule-free (P = 0.011) chest radiographs. No significant differences in TP were recorded. Radiologists report more FP decisions when given specific reporting instructions to search for nodules on chest radiographs. The relevance of clinical history supplied to radiologists is called into question and may induce a negative effect. (orig.)

Statistical significance of theoretical predictions: A new dimension in nuclear structure theories (I)

International Nuclear Information System (INIS)

DUDEK, J; SZPAK, B; FORNAL, B; PORQUET, M-G

2011-01-01

In this and the follow-up article we briefly discuss what we believe represents one of the most serious problems in contemporary nuclear structure: the question of statistical significance of parametrizations of nuclear microscopic Hamiltonians and the implied predictive power of the underlying theories. In the present Part I, we introduce the main lines of reasoning of the so-called Inverse Problem Theory, an important sub-field in the contemporary Applied Mathematics, here illustrated on the example of the Nuclear Mean-Field Approach.

Statistical Significance of the Contribution of Variables to the PCA Solution: An Alternative Permutation Strategy

Science.gov (United States)

Linting, Marielle; van Os, Bart Jan; Meulman, Jacqueline J.

2011-01-01

In this paper, the statistical significance of the contribution of variables to the principal components in principal components analysis (PCA) is assessed nonparametrically by the use of permutation tests. We compare a new strategy to a strategy used in previous research consisting of permuting the columns (variables) of a data matrix…

A Note on Comparing the Power of Test Statistics at Low Significance Levels.

Science.gov (United States)

Morris, Nathan; Elston, Robert

2011-01-01

It is an obvious fact that the power of a test statistic is dependent upon the significance (alpha) level at which the test is performed. It is perhaps a less obvious fact that the relative performance of two statistics in terms of power is also a function of the alpha level. Through numerous personal discussions, we have noted that even some competent statisticians have the mistaken intuition that relative power comparisons at traditional levels such as α = 0.05 will be roughly similar to relative power comparisons at very low levels, such as the level α = 5 × 10 -8 , which is commonly used in genome-wide association studies. In this brief note, we demonstrate that this notion is in fact quite wrong, especially with respect to comparing tests with differing degrees of freedom. In fact, at very low alpha levels the cost of additional degrees of freedom is often comparatively low. Thus we recommend that statisticians exercise caution when interpreting the results of power comparison studies which use alpha levels that will not be used in practice.

Evaluation of significance of positive familial history in prevalence of hypertension in Isfahan

Directory of Open Access Journals (Sweden)

Tavassoli A

1997-09-01

Full Text Available Hypertension is one of the most important modifiable risk factors of vascular heart disease. Control of hypertension in different age groups has a significant effect upon the control and prevention of vascular heart disease. A familial pattern is observed in the distribution of blood pressure in different societies. Family history of hypertension has a profound effect on the future risk of developing hypertension. The blood pressure of approximately 8150 inhabitants of Isfahan aged above 18 years was measured during 1993-94. Blood pressure measurements were performed according to the standards set by WHO i.e., on two separate occasions, in the sitting position, and from both arms. A questionnaire was completed consisting of 26 questions, including questions regarding history of hypertension in first and second-degree relatives. Cases with a blood pressure of 140/90 mmHg or more, were referred to the Cardiovascular Research Center of Isfahan for further evaluation. Mean systolic and diastolic blood pressure was higher in cases with a positive family history of hypertension. In this study, 37.4% of the men with hypertension and 45.4% of hypertensive women had positive history of hypertension in first-degree relatives. The association between positive family history and hypertension was not significant in men (P=0.62, but it was significant in women (P=0.000. This difference was less pronounced in the older age groups, which could be explained by the illiteracy of most of the older cases and their ignorance of the existence of hypertension in family members. After correcting for the effects of confounding factors, it appears that positive family history has a stronger association with the development of hypertension in women. Moreover, positive family history is a strong prognostic factor in the likelihood of hypertension in the children of affected cases. These findings emphasize the importance of routine blood pressure measurement in children and

Clinicopathological significance of c-MYC in esophageal squamous cell carcinoma.

Science.gov (United States)

Lian, Yu; Niu, Xiangdong; Cai, Hui; Yang, Xiaojun; Ma, Haizhong; Ma, Shixun; Zhang, Yupeng; Chen, Yifeng

2017-07-01

Esophageal squamous cell carcinoma is one of the most common malignant tumors. The oncogene c-MYC is thought to be important in the initiation, promotion, and therapy resistance of cancer. In this study, we aim to investigate the clinicopathologic roles of c-MYC in esophageal squamous cell carcinoma tissue. This study is aimed at discovering and analyzing c-MYC expression in a series of human esophageal tissues. A total of 95 esophageal squamous cell carcinoma samples were analyzed by the western blotting and immunohistochemistry techniques. Then, correlation of c-MYC expression with clinicopathological features of esophageal squamous cell carcinoma patients was statistically analyzed. In most esophageal squamous cell carcinoma cases, the c-MYC expression was positive in tumor tissues. The positive rate of c-MYC expression in tumor tissues was 61.05%, obviously higher than the adjacent normal tissues (8.42%, 8/92) and atypical hyperplasia tissues (19.75%, 16/95). There was a statistical difference among adjacent normal tissues, atypical hyperplasia tissues, and tumor tissues. Overexpression of the c-MYC was detected in 61.05% (58/95) esophageal squamous cell carcinomas, which was significantly correlated with the degree of differentiation (p = 0.004). The positive rate of c-MYC expression was 40.0% in well-differentiated esophageal tissues, with a significantly statistical difference (p = 0.004). The positive rate of c-MYC was 41.5% in T1 + T2 esophageal tissues and 74.1% in T3 + T4 esophageal tissues, with a significantly statistical difference (p = 0.001). The positive rate of c-MYC was 45.0% in I + II esophageal tissues and 72.2% in III + IV esophageal tissues, with a significantly statistical difference (p = 0.011). The c-MYC expression strongly correlated with clinical staging (p = 0.011), differentiation degree (p = 0.004), lymph node metastasis (p = 0.003), and invasion depth (p = 0.001) of patients with esophageal squamous cell carcinoma. The c-MYC was

Ensuring Positiveness of the Scaled Difference Chi-square Test Statistic.

Science.gov (United States)

Satorra, Albert; Bentler, Peter M

2010-06-01

A scaled difference test statistic [Formula: see text] that can be computed from standard software of structural equation models (SEM) by hand calculations was proposed in Satorra and Bentler (2001). The statistic [Formula: see text] is asymptotically equivalent to the scaled difference test statistic T̄(d) introduced in Satorra (2000), which requires more involved computations beyond standard output of SEM software. The test statistic [Formula: see text] has been widely used in practice, but in some applications it is negative due to negativity of its associated scaling correction. Using the implicit function theorem, this note develops an improved scaling correction leading to a new scaled difference statistic T̄(d) that avoids negative chi-square values.

ClusterSignificance: A bioconductor package facilitating statistical analysis of class cluster separations in dimensionality reduced data

DEFF Research Database (Denmark)

Serviss, Jason T.; Gådin, Jesper R.; Eriksson, Per

2017-01-01

, e.g. genes in a specific pathway, alone can separate samples into these established classes. Despite this, the evaluation of class separations is often subjective and performed via visualization. Here we present the ClusterSignificance package; a set of tools designed to assess the statistical...... significance of class separations downstream of dimensionality reduction algorithms. In addition, we demonstrate the design and utility of the ClusterSignificance package and utilize it to determine the importance of long non-coding RNA expression in the identity of multiple hematological malignancies....

Statistical significance versus clinical importance: trials on exercise therapy for chronic low back pain as example.

NARCIS (Netherlands)

van Tulder, M.W.; Malmivaara, A.; Hayden, J.; Koes, B.

2007-01-01

STUDY DESIGN. Critical appraisal of the literature. OBJECIVES. The objective of this study was to assess if results of back pain trials are statistically significant and clinically important. SUMMARY OF BACKGROUND DATA. There seems to be a discrepancy between conclusions reported by authors and

Weighted A-statistical convergence for sequences of positive linear operators.

Science.gov (United States)

Mohiuddine, S A; Alotaibi, Abdullah; Hazarika, Bipan

2014-01-01

We introduce the notion of weighted A-statistical convergence of a sequence, where A represents the nonnegative regular matrix. We also prove the Korovkin approximation theorem by using the notion of weighted A-statistical convergence. Further, we give a rate of weighted A-statistical convergence and apply the classical Bernstein polynomial to construct an illustrative example in support of our result.

Weighted A-Statistical Convergence for Sequences of Positive Linear Operators

Directory of Open Access Journals (Sweden)

S. A. Mohiuddine

2014-01-01

Full Text Available We introduce the notion of weighted A-statistical convergence of a sequence, where A represents the nonnegative regular matrix. We also prove the Korovkin approximation theorem by using the notion of weighted A-statistical convergence. Further, we give a rate of weighted A-statistical convergence and apply the classical Bernstein polynomial to construct an illustrative example in support of our result.

Indirectional statistics and the significance of an asymmetry discovered by Birch

International Nuclear Information System (INIS)

Kendall, D.G.; Young, G.A.

1984-01-01

Birch (1982, Nature, 298, 451) reported an apparent 'statistical asymmetry of the Universe'. The authors here develop 'indirectional analysis' as a technique for investigating statistical effects of this kind and conclude that the reported effect (whatever may be its origin) is strongly supported by the observations. The estimated pole of the asymmetry is at RA 13h 30m, Dec. -37deg. The angular error in its estimation is unlikely to exceed 20-30deg. (author)

Rapid Classification and Identification of Multiple Microorganisms with Accurate Statistical Significance via High-Resolution Tandem Mass Spectrometry.

Science.gov (United States)

Alves, Gelio; Wang, Guanghui; Ogurtsov, Aleksey Y; Drake, Steven K; Gucek, Marjan; Sacks, David B; Yu, Yi-Kuo

2018-06-05

Rapid and accurate identification and classification of microorganisms is of paramount importance to public health and safety. With the advance of mass spectrometry (MS) technology, the speed of identification can be greatly improved. However, the increasing number of microbes sequenced is complicating correct microbial identification even in a simple sample due to the large number of candidates present. To properly untwine candidate microbes in samples containing one or more microbes, one needs to go beyond apparent morphology or simple "fingerprinting"; to correctly prioritize the candidate microbes, one needs to have accurate statistical significance in microbial identification. We meet these challenges by using peptide-centric representations of microbes to better separate them and by augmenting our earlier analysis method that yields accurate statistical significance. Here, we present an updated analysis workflow that uses tandem MS (MS/MS) spectra for microbial identification or classification. We have demonstrated, using 226 MS/MS publicly available data files (each containing from 2500 to nearly 100,000 MS/MS spectra) and 4000 additional MS/MS data files, that the updated workflow can correctly identify multiple microbes at the genus and often the species level for samples containing more than one microbe. We have also shown that the proposed workflow computes accurate statistical significances, i.e., E values for identified peptides and unified E values for identified microbes. Our updated analysis workflow MiCId, a freely available software for Microorganism Classification and Identification, is available for download at https://www.ncbi.nlm.nih.gov/CBBresearch/Yu/downloads.html . Graphical Abstract ᅟ.

Attitudes toward statistics in medical postgraduates: measuring, evaluating and monitoring.

Science.gov (United States)

Zhang, Yuhai; Shang, Lei; Wang, Rui; Zhao, Qinbo; Li, Chanjuan; Xu, Yongyong; Su, Haixia

2012-11-23

In medical training, statistics is considered a very difficult course to learn and teach. Current studies have found that students' attitudes toward statistics can influence their learning process. Measuring, evaluating and monitoring the changes of students' attitudes toward statistics are important. Few studies have focused on the attitudes of postgraduates, especially medical postgraduates. Our purpose was to understand current attitudes regarding statistics held by medical postgraduates and explore their effects on students' achievement. We also wanted to explore the influencing factors and the sources of these attitudes and monitor their changes after a systematic statistics course. A total of 539 medical postgraduates enrolled in a systematic statistics course completed the pre-form of the Survey of Attitudes Toward Statistics -28 scale, and 83 postgraduates were selected randomly from among them to complete the post-form scale after the course. Most medical postgraduates held positive attitudes toward statistics, but they thought statistics was a very difficult subject. The attitudes mainly came from experiences in a former statistical or mathematical class. Age, level of statistical education, research experience, specialty and mathematics basis may influence postgraduate attitudes toward statistics. There were significant positive correlations between course achievement and attitudes toward statistics. In general, student attitudes showed negative changes after completing a statistics course. The importance of student attitudes toward statistics must be recognized in medical postgraduate training. To make sure all students have a positive learning environment, statistics teachers should measure their students' attitudes and monitor their change of status during a course. Some necessary assistance should be offered for those students who develop negative attitudes.

Assessing Statistically Significant Heavy-Metal Concentrations in Abandoned Mine Areas via Hot Spot Analysis of Portable XRF Data.

Science.gov (United States)

Kim, Sung-Min; Choi, Yosoon

2017-06-18

To develop appropriate measures to prevent soil contamination in abandoned mining areas, an understanding of the spatial variation of the potentially toxic trace elements (PTEs) in the soil is necessary. For the purpose of effective soil sampling, this study uses hot spot analysis, which calculates a z -score based on the Getis-Ord Gi* statistic to identify a statistically significant hot spot sample. To constitute a statistically significant hot spot, a feature with a high value should also be surrounded by other features with high values. Using relatively cost- and time-effective portable X-ray fluorescence (PXRF) analysis, sufficient input data are acquired from the Busan abandoned mine and used for hot spot analysis. To calibrate the PXRF data, which have a relatively low accuracy, the PXRF analysis data are transformed using the inductively coupled plasma atomic emission spectrometry (ICP-AES) data. The transformed PXRF data of the Busan abandoned mine are classified into four groups according to their normalized content and z -scores: high content with a high z -score (HH), high content with a low z -score (HL), low content with a high z -score (LH), and low content with a low z -score (LL). The HL and LH cases may be due to measurement errors. Additional or complementary surveys are required for the areas surrounding these suspect samples or for significant hot spot areas. The soil sampling is conducted according to a four-phase procedure in which the hot spot analysis and proposed group classification method are employed to support the development of a sampling plan for the following phase. Overall, 30, 50, 80, and 100 samples are investigated and analyzed in phases 1-4, respectively. The method implemented in this case study may be utilized in the field for the assessment of statistically significant soil contamination and the identification of areas for which an additional survey is required.

Assessing Statistically Significant Heavy-Metal Concentrations in Abandoned Mine Areas via Hot Spot Analysis of Portable XRF Data

Directory of Open Access Journals (Sweden)

Sung-Min Kim

2017-06-01

Full Text Available To develop appropriate measures to prevent soil contamination in abandoned mining areas, an understanding of the spatial variation of the potentially toxic trace elements (PTEs in the soil is necessary. For the purpose of effective soil sampling, this study uses hot spot analysis, which calculates a z-score based on the Getis-Ord Gi* statistic to identify a statistically significant hot spot sample. To constitute a statistically significant hot spot, a feature with a high value should also be surrounded by other features with high values. Using relatively cost- and time-effective portable X-ray fluorescence (PXRF analysis, sufficient input data are acquired from the Busan abandoned mine and used for hot spot analysis. To calibrate the PXRF data, which have a relatively low accuracy, the PXRF analysis data are transformed using the inductively coupled plasma atomic emission spectrometry (ICP-AES data. The transformed PXRF data of the Busan abandoned mine are classified into four groups according to their normalized content and z-scores: high content with a high z-score (HH, high content with a low z-score (HL, low content with a high z-score (LH, and low content with a low z-score (LL. The HL and LH cases may be due to measurement errors. Additional or complementary surveys are required for the areas surrounding these suspect samples or for significant hot spot areas. The soil sampling is conducted according to a four-phase procedure in which the hot spot analysis and proposed group classification method are employed to support the development of a sampling plan for the following phase. Overall, 30, 50, 80, and 100 samples are investigated and analyzed in phases 1–4, respectively. The method implemented in this case study may be utilized in the field for the assessment of statistically significant soil contamination and the identification of areas for which an additional survey is required.

Effects of positive relative accommodation on adolescent pseudomyopia with visual training

Directory of Open Access Journals (Sweden)

Jiang Yue

2014-04-01

Full Text Available AIM:To investigate the changes of the positive relative accommodation in adolescent pseudomyopia with visual training.METHODS: A total of 42 cases(84 eyeswere randomly divided into the visual training group and the control group. Visual acuity, average refraction of two groups 4wk after the training were measured, as well as positive relative accommodation(5mwere checked before the training and repeated 1, 2, 4wk after the training. Correlation analysis were given.RESULTS: There was statistically significant difference in visual acuity 4wk after the training between the two groups(PP>0.05. There was statistically significant difference in positive relative accommodation(5m1, 2, 4wk after the training between the two groups(PPCONCLUSION: Visual training has significant effect on the positive relative accommodation on adolescent pseudomyopia.

Statistical and molecular analyses of evolutionary significance of red-green color vision and color blindness in vertebrates.

Science.gov (United States)

Yokoyama, Shozo; Takenaka, Naomi

2005-04-01

Red-green color vision is strongly suspected to enhance the survival of its possessors. Despite being red-green color blind, however, many species have successfully competed in nature, which brings into question the evolutionary advantage of achieving red-green color vision. Here, we propose a new method of identifying positive selection at individual amino acid sites with the premise that if positive Darwinian selection has driven the evolution of the protein under consideration, then it should be found mostly at the branches in the phylogenetic tree where its function had changed. The statistical and molecular methods have been applied to 29 visual pigments with the wavelengths of maximal absorption at approximately 510-540 nm (green- or middle wavelength-sensitive [MWS] pigments) and at approximately 560 nm (red- or long wavelength-sensitive [LWS] pigments), which are sampled from a diverse range of vertebrate species. The results show that the MWS pigments are positively selected through amino acid replacements S180A, Y277F, and T285A and that the LWS pigments have been subjected to strong evolutionary conservation. The fact that these positively selected M/LWS pigments are found not only in animals with red-green color vision but also in those with red-green color blindness strongly suggests that both red-green color vision and color blindness have undergone adaptive evolution independently in different species.

Statistical basis for positive identification in forensic anthropology.

Science.gov (United States)

Steadman, Dawnie Wolfe; Adams, Bradley J; Konigsberg, Lyle W

2006-09-01

Forensic scientists are often expected to present the likelihood of DNA identifications in US courts based on comparative population data, yet forensic anthropologists tend not to quantify the strength of an osteological identification. Because forensic anthropologists are trained first and foremost as physical anthropologists, they emphasize estimation problems at the expense of evidentiary problems, but this approach must be reexamined. In this paper, the statistical bases for presenting osteological and dental evidence are outlined, using a forensic case as a motivating example. A brief overview of Bayesian statistics is provided, and methods to calculate likelihood ratios for five aspects of the biological profile are demonstrated. This paper emphasizes the definition of appropriate reference samples and of the "population at large," and points out the conceptual differences between them. Several databases are introduced for both reference information and to characterize the "population at large," and new data are compiled to calculate the frequency of specific characters, such as age or fractures, within the "population at large." Despite small individual likelihood ratios for age, sex, and stature in the case example, the power of this approach is that, assuming each likelihood ratio is independent, the product rule can be applied. In this particular example, it is over three million times more likely to obtain the observed osteological and dental data if the identification is correct than if the identification is incorrect. This likelihood ratio is a convincing statistic that can support the forensic anthropologist's opinion on personal identity in court. 2006 Wiley-Liss, Inc.

Statistically significant faunal differences among Middle Ordovician age, Chickamauga Group bryozoan bioherms, central Alabama

Energy Technology Data Exchange (ETDEWEB)

Crow, C.J.

1985-01-01

Middle Ordovician age Chickamauga Group carbonates crop out along the Birmingham and Murphrees Valley anticlines in central Alabama. The macrofossil contents on exposed surfaces of seven bioherms have been counted to determine their various paleontologic characteristics. Twelve groups of organisms are present in these bioherms. Dominant organisms include bryozoans, algae, brachiopods, sponges, pelmatozoans, stromatoporoids and corals. Minor accessory fauna include predators, scavengers and grazers such as gastropods, ostracods, trilobites, cephalopods and pelecypods. Vertical and horizontal niche zonation has been detected for some of the bioherm dwelling fauna. No one bioherm of those studied exhibits all 12 groups of organisms; rather, individual bioherms display various subsets of the total diversity. Statistical treatment (G-test) of the diversity data indicates a lack of statistical homogeneity of the bioherms, both within and between localities. Between-locality population heterogeneity can be ascribed to differences in biologic responses to such gross environmental factors as water depth and clarity, and energy levels. At any one locality, gross aspects of the paleoenvironments are assumed to have been more uniform. Significant differences among bioherms at any one locality may have resulted from patchy distribution of species populations, differential preservation and other factors.

Detecting Statistically Significant Communities of Triangle Motifs in Undirected Networks

Science.gov (United States)

2016-04-26

Systems, Statistics & Management Science, University of Alabama, USA. 1 DISTRIBUTION A: Distribution approved for public release. Contents 1 Summary 5...13 5 Application to Real Networks 18 5.1 2012 FBS Football Schedule Network... football schedule network. . . . . . . . . . . . . . . . . . . . . . 21 14 Stem plot of degree-ordered vertices versus the degree for college football

Attitudes toward statistics in medical postgraduates: measuring, evaluating and monitoring

Science.gov (United States)

2012-01-01

Background In medical training, statistics is considered a very difficult course to learn and teach. Current studies have found that students’ attitudes toward statistics can influence their learning process. Measuring, evaluating and monitoring the changes of students’ attitudes toward statistics are important. Few studies have focused on the attitudes of postgraduates, especially medical postgraduates. Our purpose was to understand current attitudes regarding statistics held by medical postgraduates and explore their effects on students’ achievement. We also wanted to explore the influencing factors and the sources of these attitudes and monitor their changes after a systematic statistics course. Methods A total of 539 medical postgraduates enrolled in a systematic statistics course completed the pre-form of the Survey of Attitudes Toward Statistics −28 scale, and 83 postgraduates were selected randomly from among them to complete the post-form scale after the course. Results Most medical postgraduates held positive attitudes toward statistics, but they thought statistics was a very difficult subject. The attitudes mainly came from experiences in a former statistical or mathematical class. Age, level of statistical education, research experience, specialty and mathematics basis may influence postgraduate attitudes toward statistics. There were significant positive correlations between course achievement and attitudes toward statistics. In general, student attitudes showed negative changes after completing a statistics course. Conclusions The importance of student attitudes toward statistics must be recognized in medical postgraduate training. To make sure all students have a positive learning environment, statistics teachers should measure their students’ attitudes and monitor their change of status during a course. Some necessary assistance should be offered for those students who develop negative attitudes. PMID:23173770

Statistical significant changes in ground thermal conditions of alpine Austria during the last decade

Science.gov (United States)

Kellerer-Pirklbauer, Andreas

2016-04-01

Longer data series (e.g. >10 a) of ground temperatures in alpine regions are helpful to improve the understanding regarding the effects of present climate change on distribution and thermal characteristics of seasonal frost- and permafrost-affected areas. Beginning in 2004 - and more intensively since 2006 - a permafrost and seasonal frost monitoring network was established in Central and Eastern Austria by the University of Graz. This network consists of c.60 ground temperature (surface and near-surface) monitoring sites which are located at 1922-3002 m a.s.l., at latitude 46°55'-47°22'N and at longitude 12°44'-14°41'E. These data allow conclusions about general ground thermal conditions, potential permafrost occurrence, trend during the observation period, and regional pattern of changes. Calculations and analyses of several different temperature-related parameters were accomplished. At an annual scale a region-wide statistical significant warming during the observation period was revealed by e.g. an increase in mean annual temperature values (mean, maximum) or the significant lowering of the surface frost number (F+). At a seasonal scale no significant trend of any temperature-related parameter was in most cases revealed for spring (MAM) and autumn (SON). Winter (DJF) shows only a weak warming. In contrast, the summer (JJA) season reveals in general a significant warming as confirmed by several different temperature-related parameters such as e.g. mean seasonal temperature, number of thawing degree days, number of freezing degree days, or days without night frost. On a monthly basis August shows the statistically most robust and strongest warming of all months, although regional differences occur. Despite the fact that the general ground temperature warming during the last decade is confirmed by the field data in the study region, complications in trend analyses arise by temperature anomalies (e.g. warm winter 2006/07) or substantial variations in the winter

Behavioral investment strategy matters: a statistical arbitrage approach

OpenAIRE

Sun, David; Tsai, Shih-Chuan; Wang, Wei

2011-01-01

In this study, we employ a statistical arbitrage approach to demonstrate that momentum investment strategy tend to work better in periods longer than six months, a result different from findings in past literature. Compared with standard parametric tests, the statistical arbitrage method produces more clearly that momentum strategies work only in longer formation and holding periods. Also they yield positive significant returns in an up market, but negative yet insignificant returns in a down...

Conducting tests for statistically significant differences using forest inventory data

Science.gov (United States)

James A. Westfall; Scott A. Pugh; John W. Coulston

2013-01-01

Many forest inventory and monitoring programs are based on a sample of ground plots from which estimates of forest resources are derived. In addition to evaluating metrics such as number of trees or amount of cubic wood volume, it is often desirable to make comparisons between resource attributes. To properly conduct statistical tests for differences, it is imperative...

Significant difference in p53 and p21 protein immunoreactivity in HPV 16 positive and HPV negative breast carcinomas

International Nuclear Information System (INIS)

Hennig, E.M.; Norwegian Radium Hospital, Oslo; Kvinnsland, S.; Holm, R.; Nesland, J.M.

1999-01-01

Human papillomavirus (HPV) 16 has previously been found in 19/41 breast carcinomas (46%) in women with a history of HPV 16 positive CIN III lesions. There was no significant difference in distribution of histological subtypes, mean or median tumour diameter or number of regional lymph node metastases in the HPV positive and HPV negative breast carcinoma groups. P53, p21 and c-erbB-2 proteins were analyzed by immunohistochemistry in the HPV 16 positive and HPV negative breast carcinomas. There was a significant difference in p53 and p21 protein immunoreactivity between HPV 16 positive and HPV negative breast carcinomas (p=0.0091 and p=0.0040), with a significant less detectable p53 and p21 protein immunoreactivity in the HPV 16 positive cases. There was also a significant difference in the coexpression of p53/p21 between the HPV 16 positive and HPV 16 negative breast carcinomas (p=0.002). No significant difference in immunostaining for c-erbB-2 protein in the two groups was found (p=0.15), or for the coexpression of p53/c-erbB-2 (p=0.19). The significantly lower expression of p53 and p21 proteins in HPV 16 positive than in HPV 16 negative breast carcinomas supports the hypothesis of inactivation and degradation of wild-type p53 proteins by HPV 16 E6 and that p53 mutation is not necessary for transformation in the HPV 16 positive cases. (orig.)

The distribution of P-values in medical research articles suggested selective reporting associated with statistical significance.

Science.gov (United States)

Perneger, Thomas V; Combescure, Christophe

2017-07-01

Published P-values provide a window into the global enterprise of medical research. The aim of this study was to use the distribution of published P-values to estimate the relative frequencies of null and alternative hypotheses and to seek irregularities suggestive of publication bias. This cross-sectional study included P-values published in 120 medical research articles in 2016 (30 each from the BMJ, JAMA, Lancet, and New England Journal of Medicine). The observed distribution of P-values was compared with expected distributions under the null hypothesis (i.e., uniform between 0 and 1) and the alternative hypothesis (strictly decreasing from 0 to 1). P-values were categorized according to conventional levels of statistical significance and in one-percent intervals. Among 4,158 recorded P-values, 26.1% were highly significant (P values values equal to 1, and (3) about twice as many P-values less than 0.05 compared with those more than 0.05. The latter finding was seen in both randomized trials and observational studies, and in most types of analyses, excepting heterogeneity tests and interaction tests. Under plausible assumptions, we estimate that about half of the tested hypotheses were null and the other half were alternative. This analysis suggests that statistical tests published in medical journals are not a random sample of null and alternative hypotheses but that selective reporting is prevalent. In particular, significant results are about twice as likely to be reported as nonsignificant results. Copyright © 2017 Elsevier Inc. All rights reserved.

Harmonic statistics

International Nuclear Information System (INIS)

Eliazar, Iddo

2017-01-01

The exponential, the normal, and the Poisson statistical laws are of major importance due to their universality. Harmonic statistics are as universal as the three aforementioned laws, but yet they fall short in their ‘public relations’ for the following reason: the full scope of harmonic statistics cannot be described in terms of a statistical law. In this paper we describe harmonic statistics, in their full scope, via an object termed harmonic Poisson process: a Poisson process, over the positive half-line, with a harmonic intensity. The paper reviews the harmonic Poisson process, investigates its properties, and presents the connections of this object to an assortment of topics: uniform statistics, scale invariance, random multiplicative perturbations, Pareto and inverse-Pareto statistics, exponential growth and exponential decay, power-law renormalization, convergence and domains of attraction, the Langevin equation, diffusions, Benford’s law, and 1/f noise. - Highlights: • Harmonic statistics are described and reviewed in detail. • Connections to various statistical laws are established. • Connections to perturbation, renormalization and dynamics are established.

Harmonic statistics

Energy Technology Data Exchange (ETDEWEB)

Eliazar, Iddo, E-mail: eliazar@post.tau.ac.il

2017-05-15

The exponential, the normal, and the Poisson statistical laws are of major importance due to their universality. Harmonic statistics are as universal as the three aforementioned laws, but yet they fall short in their ‘public relations’ for the following reason: the full scope of harmonic statistics cannot be described in terms of a statistical law. In this paper we describe harmonic statistics, in their full scope, via an object termed harmonic Poisson process: a Poisson process, over the positive half-line, with a harmonic intensity. The paper reviews the harmonic Poisson process, investigates its properties, and presents the connections of this object to an assortment of topics: uniform statistics, scale invariance, random multiplicative perturbations, Pareto and inverse-Pareto statistics, exponential growth and exponential decay, power-law renormalization, convergence and domains of attraction, the Langevin equation, diffusions, Benford’s law, and 1/f noise. - Highlights: • Harmonic statistics are described and reviewed in detail. • Connections to various statistical laws are established. • Connections to perturbation, renormalization and dynamics are established.

Statistical distribution of hydrogen over three positions in the brucite Mg(OH)2 structure from electron diffractometry data

International Nuclear Information System (INIS)

Zhukhlistov, A.A.; Avilov, A.S.; Ferraris, D.; Zvyagin, B.B.; Plotnikov, V.P.

1997-01-01

The method of improved automatic electron diffractometry for measuring and recording intensities to two-dimensionally distributed reflections of texture-type electron diffraction patterns has been used for the analysis of the brucite Mg(OH) 2 structure. The experimental accuracy of the measured intensities proved to be sufficient for studying fine structural details of the statistical distribution of hydrogen atoms over three structure positions located around the threefold axis of the brucite structure

Induction position for spinal anaesthesia: Sitting versus lateral position

International Nuclear Information System (INIS)

Shahzad, K.; Afshan, G.

2013-01-01

Objective: To compare the effect of induction position on block characteristics (sensory and motor nerves) and haemodynamic stability in elderly patients with isobaric bupivacaine. Patient comfort was also looked at. Methods: The randomized single blinded study was conducted at the Aga Khan University Hospital, Karachi, from September 2007 to August 2008. A total of 70 patients aged >60 years of both genders were included. Spinal anaesthesia was performed either in sitting or lateral position according to random allocation. Assessments of sensory, motor block and heart rate, systolic and diastolic blood pressure were recorded for 20 minutes. SPSS 16 was used for statistical analysis. Results: There was no significant difference for haemodynamic variables heart rate, systolic and diastolic blood pressure. The onset of anaesthesia was faster in the sitting group (4.5 minutes vs 5.4 minutes). The motor block characteristics were similar in both the groups. The majority of patients who reported 'very comfortable' for induction position belonged to the lateral group. Conclusion: Both sitting and lateral positions have similar effects on sensory and motor blockade and haemodynamic stability. However, patients generally found lateral position very comfortable. (author)

Perceived Statistical Knowledge Level and Self-Reported Statistical Practice Among Academic Psychologists

Directory of Open Access Journals (Sweden)

Laura Badenes-Ribera

2018-06-01

Full Text Available Introduction: Publications arguing against the null hypothesis significance testing (NHST procedure and in favor of good statistical practices have increased. The most frequently mentioned alternatives to NHST are effect size statistics (ES, confidence intervals (CIs, and meta-analyses. A recent survey conducted in Spain found that academic psychologists have poor knowledge about effect size statistics, confidence intervals, and graphic displays for meta-analyses, which might lead to a misinterpretation of the results. In addition, it also found that, although the use of ES is becoming generalized, the same thing is not true for CIs. Finally, academics with greater knowledge about ES statistics presented a profile closer to good statistical practice and research design. Our main purpose was to analyze the extension of these results to a different geographical area through a replication study.Methods: For this purpose, we elaborated an on-line survey that included the same items as the original research, and we asked academic psychologists to indicate their level of knowledge about ES, their CIs, and meta-analyses, and how they use them. The sample consisted of 159 Italian academic psychologists (54.09% women, mean age of 47.65 years. The mean number of years in the position of professor was 12.90 (SD = 10.21.Results: As in the original research, the results showed that, although the use of effect size estimates is becoming generalized, an under-reporting of CIs for ES persists. The most frequent ES statistics mentioned were Cohen's d and R2/η2, which can have outliers or show non-normality or violate statistical assumptions. In addition, academics showed poor knowledge about meta-analytic displays (e.g., forest plot and funnel plot and quality checklists for studies. Finally, academics with higher-level knowledge about ES statistics seem to have a profile closer to good statistical practices.Conclusions: Changing statistical practice is not

Sigsearch: a new term for post hoc unplanned search for statistically significant relationships with the intent to create publishable findings.

Science.gov (United States)

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.

Future time perspective and positive health practices in young adults: an extension.

Science.gov (United States)

Mahon, N E; Yarcheski, T J; Yarcheski, A

1997-06-01

A sample of 69 young adults attending a public university responded to the Future Time Perspective Inventory, two subscales of the Time Experience Scales (Fast and Slow Tempo), and the Personal Lifestyle Questionnaire in classroom settings. A statistically significant correlation (.52) was found between scores for future time perspective and the ratings for the practice of positive health behaviors in young adults. This correlation was larger than those previously found for middle and late adolescents. Scores on subscales of individual health practices and future time perspective indicated statistically significant correlations for five (.25 to .56) of the six subscales. Scores on neither Fast nor Slow Tempo were related to ratings of positive health practices or ratings on subscales measuring positive health practices.

Intelligent system for statistically significant expertise knowledge on the basis of the model of self-organizing nonequilibrium dissipative system

Directory of Open Access Journals (Sweden)

E. A. Tatokchin

2017-01-01

Full Text Available Development of the modern educational technologies caused by broad introduction of comput-er testing and development of distant forms of education does necessary revision of methods of an examination of pupils. In work it was shown, need transition to mathematical criteria, exami-nations of knowledge which are deprived of subjectivity. In article the review of the problems arising at realization of this task and are offered approaches for its decision. The greatest atten-tion is paid to discussion of a problem of objective transformation of rated estimates of the ex-pert on to the scale estimates of the student. In general, the discussion this question is was con-cluded that the solution to this problem lies in the creation of specialized intellectual systems. The basis for constructing intelligent system laid the mathematical model of self-organizing nonequilibrium dissipative system, which is a group of students. This article assumes that the dissipative system is provided by the constant influx of new test items of the expert and non-equilibrium – individual psychological characteristics of students in the group. As a result, the system must self-organize themselves into stable patterns. This patern will allow for, relying on large amounts of data, get a statistically significant assessment of student. To justify the pro-posed approach in the work presents the data of the statistical analysis of the results of testing a large sample of students (> 90. Conclusions from this statistical analysis allowed to develop intelligent system statistically significant examination of student performance. It is based on data clustering algorithm (k-mean for the three key parameters. It is shown that this approach allows you to create of the dynamics and objective expertise evaluation.

The Importance of Integrating Clinical Relevance and Statistical Significance in the Assessment of Quality of Care--Illustrated Using the Swedish Stroke Register.

Directory of Open Access Journals (Sweden)

Anita Lindmark

Full Text Available When profiling hospital performance, quality inicators are commonly evaluated through hospital-specific adjusted means with confidence intervals. When identifying deviations from a norm, large hospitals can have statistically significant results even for clinically irrelevant deviations while important deviations in small hospitals can remain undiscovered. We have used data from the Swedish Stroke Register (Riksstroke to illustrate the properties of a benchmarking method that integrates considerations of both clinical relevance and level of statistical significance.The performance measure used was case-mix adjusted risk of death or dependency in activities of daily living within 3 months after stroke. A hospital was labeled as having outlying performance if its case-mix adjusted risk exceeded a benchmark value with a specified statistical confidence level. The benchmark was expressed relative to the population risk and should reflect the clinically relevant deviation that is to be detected. A simulation study based on Riksstroke patient data from 2008-2009 was performed to investigate the effect of the choice of the statistical confidence level and benchmark value on the diagnostic properties of the method.Simulations were based on 18,309 patients in 76 hospitals. The widely used setting, comparing 95% confidence intervals to the national average, resulted in low sensitivity (0.252 and high specificity (0.991. There were large variations in sensitivity and specificity for different requirements of statistical confidence. Lowering statistical confidence improved sensitivity with a relatively smaller loss of specificity. Variations due to different benchmark values were smaller, especially for sensitivity. This allows the choice of a clinically relevant benchmark to be driven by clinical factors without major concerns about sufficiently reliable evidence.The study emphasizes the importance of combining clinical relevance and level of statistical

The Importance of Integrating Clinical Relevance and Statistical Significance in the Assessment of Quality of Care--Illustrated Using the Swedish Stroke Register.

Science.gov (United States)

Lindmark, Anita; van Rompaye, Bart; Goetghebeur, Els; Glader, Eva-Lotta; Eriksson, Marie

2016-01-01

When profiling hospital performance, quality inicators are commonly evaluated through hospital-specific adjusted means with confidence intervals. When identifying deviations from a norm, large hospitals can have statistically significant results even for clinically irrelevant deviations while important deviations in small hospitals can remain undiscovered. We have used data from the Swedish Stroke Register (Riksstroke) to illustrate the properties of a benchmarking method that integrates considerations of both clinical relevance and level of statistical significance. The performance measure used was case-mix adjusted risk of death or dependency in activities of daily living within 3 months after stroke. A hospital was labeled as having outlying performance if its case-mix adjusted risk exceeded a benchmark value with a specified statistical confidence level. The benchmark was expressed relative to the population risk and should reflect the clinically relevant deviation that is to be detected. A simulation study based on Riksstroke patient data from 2008-2009 was performed to investigate the effect of the choice of the statistical confidence level and benchmark value on the diagnostic properties of the method. Simulations were based on 18,309 patients in 76 hospitals. The widely used setting, comparing 95% confidence intervals to the national average, resulted in low sensitivity (0.252) and high specificity (0.991). There were large variations in sensitivity and specificity for different requirements of statistical confidence. Lowering statistical confidence improved sensitivity with a relatively smaller loss of specificity. Variations due to different benchmark values were smaller, especially for sensitivity. This allows the choice of a clinically relevant benchmark to be driven by clinical factors without major concerns about sufficiently reliable evidence. The study emphasizes the importance of combining clinical relevance and level of statistical confidence when

Diagnosing Human Papillomavirus and Human Papillomavirus Type 16 By Real-Time PCR in Patient Undergone to Colposcopy and Significance of the Diagnosis

Directory of Open Access Journals (Sweden)

Sibel Özdaş

2013-06-01

Full Text Available Objective: It is aimed to determine presence of HPV and HPV 16 by Real-Time PCR in cervical smears obtained from patients during colposcopic examination who had referred to outpatient clinic of Gynecology and Obstetrics Department due to various complaints and to examine interrelation between positive test results and clinical data. Method: Sixty patients were included in the study who were referred to outpatient clinic due to vary complaints and who had been decided to undergo to colposcopic examination. DNA was obtained from each smear sample by phenol-chloroform-isoamylalcohol method. L1 region was replicated in amplification process using MY09/MY11 primers. Products for Nested Real time PCR were studied in Ligth Cycler equipment by GP5+/GP6+ primers and Cyanine-5 labeled HPV 16 DNA specific probe. Real time PCR products were undergone melting curve analysis by LigthCycler software version 3.5.3. HPV DNA positivity and HPV 16 positivity were determined at 78-82°C and 68°C, respectively. Results: No statistically significant difference could be detected between HPV positivity, HPV 16 in and types other than HPV 16 control group and patients with positive test result as a consequence of colposcopic examination. Again, no statistically significant difference could be detected between HPV positivity and status of parity, result of PAP test, marital status and age of patient. Conclusion: No statistically significant difference could be detected between HPV positivity, HPV 16 in and types other than HPV 16 control group and patients with positive test result as a consequence of colposcopic examination. Again, no statistically difference could be detected between HPV positivity and result of PAP smear test, marital status, age of patient and smoking but statistically significant difference could be detected between types other than HPV 16 and status of parity (respectively; χ2=0.821, p=0.365; χ2=0.752, p=0.564; χ2=0.364, p=0.834; χ2= 6.835, p

Test the Overall Significance of p-values by Using Joint Tail Probability of Ordered p-values as Test Statistic

NARCIS (Netherlands)

Fang, Yongxiang; Wit, Ernst

2008-01-01

Fisher’s combined probability test is the most commonly used method to test the overall significance of a set independent p-values. However, it is very obviously that Fisher’s statistic is more sensitive to smaller p-values than to larger p-value and a small p-value may overrule the other p-values

21-Gene Recurrence Score and Locoregional Recurrence in Node-Positive/ER-Positive Breast Cancer Treated With Chemo-Endocrine Therapy.

Science.gov (United States)

Mamounas, Eleftherios P; Liu, Qing; Paik, Soonmyung; Baehner, Frederick L; Tang, Gong; Jeong, Jong-Hyeon; Kim, S Rim; Butler, Steven M; Jamshidian, Farid; Cherbavaz, Diana B; Sing, Amy P; Shak, Steven; Julian, Thomas B; Lembersky, Barry C; Wickerham, D Lawrence; Costantino, Joseph P; Wolmark, Norman

2017-01-01

The 21-gene recurrence score (RS) predicts risk of locoregional recurrence (LRR) in node-negative, estrogen receptor (ER)-positive breast cancer. We evaluated the association between RS and LRR in node-positive, ER-positive patients treated with adjuvant chemotherapy plus tamoxifen in National Surgical Adjuvant Breast and Bowel Project B-28. B-28 compared doxorubicin/cyclophosphamide (AC X 4) with AC X 4 followed by paclitaxel X 4. Tamoxifen was given to patients age 50 years or older and those younger than age 50 years with ER-positive and/or progesterone receptor-positive tumors. Lumpectomy patients received breast radiotherapy. Mastectomy patients received no radiotherapy. The present study includes 1065 ER-positive, tamoxifen-treated patients with RS assessment. Cumulative incidence functions and subdistribution hazard regression models were used for LRR to account for competing risks including distant recurrence, second primary cancers, and death from other causes. Median follow-up was 11.2 years. All statistical tests were one-sided. There were 80 LRRs (7.5%) as first events (68% local/32% regional). RS was low: 36.2%; intermediate: 34.2%; and high: 29.6%. RS was a statistically significant predictor of LRR in univariate analyses (10-year cumulative incidence of LRR = 3.3%, 7.2%, and 12.2% for low, intermediate, and high RS, respectively, P < .001). In multivariable regression analysis, RS remained an independent predictor of LRR (hazard ratio [HR] = 2.59, 95% confidence interval [CI] = 1.28 to 5.26, for a 50-point difference, P = .008) along with pathologic nodal status (HR = 1.91, 95% CI = 1.20 to 3.03, for four or more vs one to three positive nodes, P = .006) and tumor size (HR = 1.28, 95% CI = 1.05 to 1.55, for a 1 cm difference, P = .02). RS statistically significantly predicts risk of LRR in node-positive, ER-positive breast cancer patients after adjuvant chemotherapy plus tamoxifen. These findings can help in the selection of

Interventions to significantly improve service uptake and retention of HIV-positive pregnant women and HIV-exposed infants along the prevention of mother-to-child transmission continuum of care: systematic review.

Science.gov (United States)

Vrazo, Alexandra C; Firth, Jacqueline; Amzel, Anouk; Sedillo, Rebecca; Ryan, Julia; Phelps, B Ryan

2018-02-01

Despite the success of Prevention of Mother-to-Child Transmission of HIV (PMTCT) programmes, low uptake of services and poor retention pose a formidable challenge to achieving the elimination of vertical HIV transmission in low- and middle-income countries. This systematic review summarises interventions that demonstrate statistically significant improvements in service uptake and retention of HIV-positive pregnant and breastfeeding women and their infants along the PMTCT cascade. Databases were systematically searched for peer-reviewed studies. Outcomes of interest included uptake of services, such as antiretroviral therapy (ART) such as initiation, early infant diagnostic testing, and retention of HIV-positive pregnant and breastfeeding women and their infants. Interventions that led to statistically significant outcomes were included and mapped to the PMTCT cascade. An eight-item assessment tool assessed study rigour. CRD42017063816. Of 686 citations reviewed, 11 articles met inclusion criteria. Ten studies detailed maternal outcomes and seven studies detailed infant outcomes in PMTCT programmes. Interventions to increase access to antenatal care (ANC) and ART services (n = 4) and those using lay cadres (n = 3) were most common. Other interventions included quality improvement (n = 2), mHealth (n = 1), and counselling (n = 1). One study described interventions in an Option B+ programme. Limitations included lack of HIV testing and counselling and viral load monitoring outcomes, small sample size, geographical location, and non-randomized assignment and selection of participants. Interventions including ANC/ART integration, family-centred approaches, and the use of lay healthcare providers are demonstrably effective in increasing service uptake and retention of HIV-positive mothers and their infants in PMTCT programmes. Future studies should include control groups and assess whether interventions developed in the context of earlier 'Options' are

Statistical determination of significant curved I-girder bridge seismic response parameters

Science.gov (United States)

Seo, Junwon

2013-06-01

Curved steel bridges are commonly used at interchanges in transportation networks and more of these structures continue to be designed and built in the United States. Though the use of these bridges continues to increase in locations that experience high seismicity, the effects of curvature and other parameters on their seismic behaviors have been neglected in current risk assessment tools. These tools can evaluate the seismic vulnerability of a transportation network using fragility curves. One critical component of fragility curve development for curved steel bridges is the completion of sensitivity analyses that help identify influential parameters related to their seismic response. In this study, an accessible inventory of existing curved steel girder bridges located primarily in the Mid-Atlantic United States (MAUS) was used to establish statistical characteristics used as inputs for a seismic sensitivity study. Critical seismic response quantities were captured using 3D nonlinear finite element models. Influential parameters from these quantities were identified using statistical tools that incorporate experimental Plackett-Burman Design (PBD), which included Pareto optimal plots and prediction profiler techniques. The findings revealed that the potential variation in the influential parameters included number of spans, radius of curvature, maximum span length, girder spacing, and cross-frame spacing. These parameters showed varying levels of influence on the critical bridge response.

Medical Statistics – Mathematics or Oracle? Farewell Lecture

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Gaus, Wilhelm

2005-06-01

Full Text Available Certainty is rare in medicine. This is a direct consequence of the individuality of each and every human being and the reason why we need medical statistics. However, statistics have their pitfalls, too. Fig. 1 shows that the suicide rate peaks in youth, while in Fig. 2 the rate is highest in midlife and Fig. 3 in old age. Which of these contradictory messages is right? After an introduction to the principles of statistical testing, this lecture examines the probability with which statistical test results are correct. For this purpose the level of significance and the power of the test are compared with the sensitivity and specificity of a diagnostic procedure. The probability of obtaining correct statistical test results is the same as that for the positive and negative correctness of a diagnostic procedure and therefore depends on prevalence. The focus then shifts to the problem of multiple statistical testing. The lecture demonstrates that for each data set of reasonable size at least one test result proves to be significant - even if the data set is produced by a random number generator. It is extremely important that a hypothesis is generated independently from the data used for its testing. These considerations enable us to understand the gradation of "lame excuses, lies and statistics" and the difference between pure truth and the full truth. Finally, two historical oracles are cited.

False-positive results in pharmacoepidemiology and pharmacovigilance.

Science.gov (United States)

Bezin, Julien; Bosco-Levy, Pauline; Pariente, Antoine

2017-09-01

False-positive constitute an important issue in scientific research. In the domain of drug evaluation, it affects all phases of drug development and assessment, from the very early preclinical studies to the late post-marketing evaluations. The core concern associated with this false-positive is the lack of replicability of the results. Aside from fraud or misconducts, false-positive is often envisioned from the statistical angle, which considers them as a price to pay for type I error in statistical testing, and its inflation in the context of multiple testing. If envisioning this problematic in the context of pharmacoepidemiology and pharmacovigilance however, that both evaluate drugs in an observational settings, information brought by statistical testing and the significance of such should only be considered as additional to the estimates provided and their confidence interval, in a context where differences have to be a clinically meaningful upon everything, and the results appear robust to the biases likely to have affected the studies. In the following article, we consequently illustrate these biases and their consequences in generating false-positive results, through studies and associations between drug use and health outcomes that have been widely disputed. Copyright © 2017 Société française de pharmacologie et de thérapeutique. Published by Elsevier Masson SAS. All rights reserved.

The Health Significance of Positive Emotions in Adulthood and Later Life

OpenAIRE

Ong, Anthony D.; Mroczek, Daniel K.; Riffin, Catherine

2011-01-01

A growing body of literature supports a link between positive emotions and health in older adults. In this article, we review evidence of the effects of positive emotions on downstream biological processes and meaningful clinical endpoints, such as adult morbidity and mortality. We then present relevant predictions from lifespan theories that suggest changes in cognition and motivation may play an important role in explaining how positive emotions are well maintained in old age, despite perva...

Statistical analysis of traversal behavior under different types of traffic lights

Science.gov (United States)

Wang, Boran; Wang, Ziyang; Li, Zhiyin

2017-12-01

According to the video observation, it is found that the traffic signal type signal has a significant effect on the illegal crossing behavior of pedestrians at the intersection. Through the method of statistical analysis and variance analysis, the difference between the violation rate and the waiting position of pedestrians at different intersecting lights is compared, and the influence of traffic signal type on pedestrian crossing behavior is evaluated. The results show that the violation rate of the intersection of the static pedestrian lights is significantly higher than that of the countdown signal lights. There are significant differences in the waiting position of the intersection of different signal lights.

Extra-nodal extension is a significant prognostic factor in lymph node positive breast cancer.

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Sura Aziz

Full Text Available Presence of lymph node (LN metastasis is a strong prognostic factor in breast cancer, whereas the importance of extra-nodal extension and other nodal tumor features have not yet been fully recognized. Here, we examined microscopic features of lymph node metastases and their prognostic value in a population-based cohort of node positive breast cancer (n = 218, as part of the prospective Norwegian Breast Cancer Screening Program NBCSP (1996-2009. Sections were reviewed for the largest metastatic tumor diameter (TD-MET, nodal afferent and efferent vascular invasion (AVI and EVI, extra-nodal extension (ENE, number of ENE foci, as well as circumferential (CD-ENE and perpendicular (PD-ENE diameter of extra-nodal growth. Number of positive lymph nodes, EVI, and PD-ENE were significantly increased with larger primary tumor (PT diameter. Univariate survival analysis showed that several features of nodal metastases were associated with disease-free (DFS or breast cancer specific survival (BCSS. Multivariate analysis demonstrated an independent prognostic value of PD-ENE (with 3 mm as cut-off value in predicting DFS and BCSS, along with number of positive nodes and histologic grade of the primary tumor (for DFS: P = 0.01, P = 0.02, P = 0.01, respectively; for BCSS: P = 0.02, P = 0.008, P = 0.02, respectively. To conclude, the extent of ENE by its perpendicular diameter was independently prognostic and should be considered in line with nodal tumor burden in treatment decisions of node positive breast cancer.

How to construct the statistic network? An association network of herbaceous

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WenJun Zhang

2012-06-01

Full Text Available In present study I defined a new type of network, the statistic network. The statistic network is a weighted and non-deterministic network. In the statistic network, a connection value, i.e., connection weight, represents connection strength and connection likelihood between two nodes and its absolute value falls in the interval (0,1]. The connection value is expressed as a statistical measure such as correlation coefficient, association coefficient, or Jaccard coefficient, etc. In addition, all connections of the statistic network can be statistically tested for their validity. A connection is true if the connection value is statistically significant. If all connection values of a node are not statistically significant, it is an isolated node. An isolated node has not any connection to other nodes in the statistic network. Positive and negative connection values denote distinct connectiontypes (positive or negative association or interaction. In the statistic network, two nodes with the greater connection value will show more similar trend in the change of their states. At any time we can obtain a sample network of the statistic network. A sample network is a non-weighted and deterministic network. Thestatistic network, in particular the plant association network that constructed from field sampling, is mostly an information network. Most of the interspecific relationships in plant community are competition and cooperation. Therefore in comparison to animal networks, the methodology of statistic network is moresuitable to construct plant association networks. Some conclusions were drawn from this study: (1 in the plant association network, most connections are weak and positive interactions. The association network constructed from Spearman rank correlation has most connections and isolated taxa are fewer. From net linear correlation,linear correlation, to Spearman rank correlation, the practical number of connections and connectance in the

Evaluation of the Positive Re-Entry in Corrections Program: A Positive Psychology Intervention With Prison Inmates.

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Huynh, Kim H; Hall, Brittany; Hurst, Mark A; Bikos, Lynette H

2015-08-01

Two groups of male inmates (n = 31, n = 31) participated in the Positive Re-Entry in Corrections Program (PRCP). This positive psychology intervention focused on teaching offenders skills that facilitate re-entry into the community. Offenders participated in weekly lectures, discussions, and homework assignments focused on positive psychology principles. The two groups differed in duration of treatment (8 weeks and 12 weeks). Participants completed pre- and post-intervention measures of gratitude, hope, and life satisfaction. Using a 2 × 2 mixed design ANOVA, we hypothesized that the intervention (with two between-subjects levels of 8 and 12 weeks) and duration (with two repeated measures levels of pre and post) of treatment would moderate pre- to post-intervention change. Results indicated significant differences on pre- and post-intervention scores for both groups of offenders on all measures. The analysis did not yield statistically significant differences between groups, demonstrating no additive benefits from the inclusion of four additional sessions, thus saving time and money for correctional programming and funding. This research supports the use of positive psychology in prison interventions. © The Author(s) 2014.

Statistically significant dependence of the Xaa-Pro peptide bond conformation on secondary structure and amino acid sequence

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Leitner Dietmar

2005-04-01

Full Text Available Abstract Background A reliable prediction of the Xaa-Pro peptide bond conformation would be a useful tool for many protein structure calculation methods. We have analyzed the Protein Data Bank and show that the combined use of sequential and structural information has a predictive value for the assessment of the cis versus trans peptide bond conformation of Xaa-Pro within proteins. For the analysis of the data sets different statistical methods such as the calculation of the Chou-Fasman parameters and occurrence matrices were used. Furthermore we analyzed the relationship between the relative solvent accessibility and the relative occurrence of prolines in the cis and in the trans conformation. Results One of the main results of the statistical investigations is the ranking of the secondary structure and sequence information with respect to the prediction of the Xaa-Pro peptide bond conformation. We observed a significant impact of secondary structure information on the occurrence of the Xaa-Pro peptide bond conformation, while the sequence information of amino acids neighboring proline is of little predictive value for the conformation of this bond. Conclusion In this work, we present an extensive analysis of the occurrence of the cis and trans proline conformation in proteins. Based on the data set, we derived patterns and rules for a possible prediction of the proline conformation. Upon adoption of the Chou-Fasman parameters, we are able to derive statistically relevant correlations between the secondary structure of amino acid fragments and the Xaa-Pro peptide bond conformation.

The impact of reorienting cone-beam computed tomographic images in varied head positions on the coordinates of anatomical landmarks

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Kim, Jae Hun; Jeong, Ho Gul; Hwang, Jae Joon; Lee, Jung Hee; Han, Sang Sun [Dept. of Oral and Maxillofacial Radiology, Yonsei University, College of Dentistry, Seoul (Korea, Republic of)

2016-06-15

The aim of this study was to compare the coordinates of anatomical landmarks on cone-beam computed tomographic (CBCT) images in varied head positions before and after reorientation using image analysis software. CBCT images were taken in a normal position and four varied head positions using a dry skull marked with 3 points where gutta percha was fixed. In each of the five radiographic images, reference points were set, 20 anatomical landmarks were identified, and each set of coordinates was calculated. Coordinates in the images from the normally positioned head were compared with those in the images obtained from varied head positions using statistical methods. Post-reorientation coordinates calculated using a three-dimensional image analysis program were also compared to the reference coordinates. In the original images, statistically significant differences were found between coordinates in the normal-position and varied-position images. However, post-reorientation, no statistically significant differences were found between coordinates in the normal-position and varied-position images. The changes in head position impacted the coordinates of the anatomical landmarks in three-dimensional images. However, reorientation using image analysis software allowed accurate superimposition onto the reference positions.

CONFIDENCE LEVELS AND/VS. STATISTICAL HYPOTHESIS TESTING IN STATISTICAL ANALYSIS. CASE STUDY

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ILEANA BRUDIU

2009-05-01

Full Text Available Estimated parameters with confidence intervals and testing statistical assumptions used in statistical analysis to obtain conclusions on research from a sample extracted from the population. Paper to the case study presented aims to highlight the importance of volume of sample taken in the study and how this reflects on the results obtained when using confidence intervals and testing for pregnant. If statistical testing hypotheses not only give an answer "yes" or "no" to some questions of statistical estimation using statistical confidence intervals provides more information than a test statistic, show high degree of uncertainty arising from small samples and findings build in the "marginally significant" or "almost significant (p very close to 0.05.

Relation Between Intelligence and Family Size, Position, and Income in Adolescent Girls in Saudi Arabia.

Science.gov (United States)

Osman, Habab; Alahmadi, Maryam; Bakhiet, Salaheldin; Lynn, Richard

2016-12-01

Data are reported showing statistically significant negative correlations between intelligence and family size, position, and income in a sample of 604 adolescent girls in Saudi Arabia. There were no statistically significant correlations or associations between whether the mother or father were deceased or both parents were alive, and whether the parents were living together or were divorced. © The Author(s) 2016.

EFFECT OF BODY POSITIONS ON INTRA OCULAR PRESSURE

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Rajendra

2015-09-01

Full Text Available BACKGROUND: Intra Ocular Pressure (IOP can be altered by changing body position. Very few studies are available in the Indian subjects. AIM: To study the effect of changes in the body position from upright posture to supine to head down tilt of - 60 0 . MATERIALS AND M ETHODS: The study group consisted of 60 subjects, 35 boys and 25 girls in the age group of 18 to 24 years, with no ocular pathology were chosen. Independent measurements of the IOP of each eye were obtained. Keelar Pulsair air impulse tonometer was used in all the subjects for IOP measurement. IOP was measured in the department of Ophthalmology, Teaching Hospital between 10AM to 12 Noon. STATISTICAL ANALYSIS : were done using Student’s paired ‘t’ test. RESULTS: The change of IOP (Increased induced by the change of position between the means of IOP’s for the sitting and supine positions was 2.789±1.03 mm Hg of all subjects, 2.825±0.226 mm Hg in males and 2.739±0.089 mm Hg in females and between the supine and in clined - 60 ⁰ position was 4.971±0.914 mm Hg of all subjects, 4.703±0.816mm Hg in males and 5.346±1.098 mm Hg in females. CONCLUSION: It is apparent that, the IOP is significantly higher in the supine than in the sitting and in the inclined than in the supin e positions. The difference was statistically significant (P<0.001.

How to practise Bayesian statistics outside the Bayesian church: What philosophy for Bayesian statistical modelling?

NARCIS (Netherlands)

Borsboom, D.; Haig, B.D.

2013-01-01

Unlike most other statistical frameworks, Bayesian statistical inference is wedded to a particular approach in the philosophy of science (see Howson & Urbach, 2006); this approach is called Bayesianism. Rather than being concerned with model fitting, this position in the philosophy of science

Statistical methods for transverse beam position diagnostics with higher order modes in third harmonic 3.9 GHz superconducting accelerating cavities at FLASH

CERN Document Server

Zhang, P; Jones, R M

2014-01-01

Beam-excited higher order modes (HOM) can be used to provide beam diagnostics. Here we focus on 3.9 GHz superconducting accelerating cavities. In particular we study dipole mode excitation and its application to beam position determinations. In order to extract beam position information, linear regression can be used. Due to a large number of sampling points in the waveforms, statistical methods are used to effectively reduce the dimension of the system, such as singular value decomposition (SVD) and k-means clustering. These are compared with the direct linear regression (DLR) on the entire waveforms. A cross-validation technique is used to study the sample independent precisions of the position predictions given by these three methods. A RMS prediction error in the beam position of approximately 50 micron can be achieved by DLR and SVD, while k-means clustering suggests 70 micron.

Significant positive relationship between serum magnesium and muscle quality in maintenance hemodialysis patients.

Science.gov (United States)

Okazaki, Hisanori; Ishimura, Eiji; Okuno, Senji; Norimine, Kyoko; Yamakawa, Kenjiro; Yamakawa, Tomoyuki; Shoji, Shigeichi; Nishizawa, Yoshiki; Inaba, Masaaki

2013-01-01

Serum magnesium (Mg) levels have been associated with muscle performance in the general population. We hypothesized that serum Mg would be associated with muscle quality in hemodialysis patients. A total of 310 patients were examined (age: 58 ± 12 years, hemodialysis duration: 6.4 ± 6.0 years, 60.6% men, and 36.1% diabetics). Arm lean mass was measured by dual energy X-ray absorptiometry (DXA) on the dominant side. Arm muscle quality was defined as the ratio of the handgrip strength to the arm lean mass of the same side (kg/kg). Serum Mg was 1.15 ± 0.16 mmol/L (2.8 ± 0.4 mg/dL), being higher than the reference range of normal subjects. There was a significant negative correlation between muscle quality and age (r = -0.326, p<0.0001) and duration of hemodialysis (r = -0.253, p<0.0001). The muscle quality of the diabetics was significantly lower than that of the non-diabetics (p<0.001). There was a significant, positive correlation between muscle quality and serum Mg (r = 0.118, p<0.05), but not serum calcium or phosphate. In multiple regression analysis, age, gender, hemodialysis duration, diabetes, and serum Mg (β = 0.129, p<0.05) were significantly and independently associated with muscle quality (R(2) = 0.298, p<0.0001). These results demonstrated that a lower serum Mg concentration was significantly associated with poor muscle quality in hemodialysis patients. Further studies are needed to explore the mechanism by which lower serum Mg affects muscle quality.

Measure of significance of holotropic breathwork in the development of self-awareness

DEFF Research Database (Denmark)

Miller, Tanja; Nielsen, Laila

2015-01-01

OBJECTIVES: To investigate whether Holotropic Breathwork™ (HB; Grof Transpersonal Training, Mill Valley, CA) has any significance in the development of self-awareness. DESIGN: A quasi-experiment design and multiple case studies. A single case design was replicated. The statistical design was a re......OBJECTIVES: To investigate whether Holotropic Breathwork™ (HB; Grof Transpersonal Training, Mill Valley, CA) has any significance in the development of self-awareness. DESIGN: A quasi-experiment design and multiple case studies. A single case design was replicated. The statistical design...... MEASURES: The novices (n = 9) underwent positive temperament changes and the experienced participants (n = 11) underwent positive changes in character. Overall, positive self-awareness changes were indicated; the participants' (n = 20) scores for persistence temperament, interpersonal problems, overly.......864; pre-during-test p = 0.0215, pre-post-test p = 0.021, pre-post-test d = 0.5). Pre-test hostility mean (50.50 ± 10.395) decreased at post-test (47.20 ± 9.001; p = 0.0185; d = 0.3). The Inventory of Interpersonal Problems total pre-test mean (59.05 ± 17.139) was decreased at post-test (54.8 ± 12.408; p...

Computational and Statistical Aspects of Determining Ship’s Position

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Drapella Antoni

2017-12-01

Full Text Available In its mathematical essence, the task of determining ship’s position coordinates, is to minimize appropriately defined goal function. This paper proposes to use the method of conjugate gradient for this purpose. The reason is that calculations may be performed in some seconds time because Microsoft and Apache implemented the conjugate gradient method as a tool called the Solver and embedded this tool in their widely offered and popular spreadsheets, namely Excel and the Open Office Calc, respectively. Further in this paper it is shown how to precisely assess errors of ship’s position coordinates with the Monte Carlo method that employs the Solver.

Official statistics and Big Data

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Peter Struijs

2014-07-01

Full Text Available The rise of Big Data changes the context in which organisations producing official statistics operate. Big Data provides opportunities, but in order to make optimal use of Big Data, a number of challenges have to be addressed. This stimulates increased collaboration between National Statistical Institutes, Big Data holders, businesses and universities. In time, this may lead to a shift in the role of statistical institutes in the provision of high-quality and impartial statistical information to society. In this paper, the changes in context, the opportunities, the challenges and the way to collaborate are addressed. The collaboration between the various stakeholders will involve each partner building on and contributing different strengths. For national statistical offices, traditional strengths include, on the one hand, the ability to collect data and combine data sources with statistical products and, on the other hand, their focus on quality, transparency and sound methodology. In the Big Data era of competing and multiplying data sources, they continue to have a unique knowledge of official statistical production methods. And their impartiality and respect for privacy as enshrined in law uniquely position them as a trusted third party. Based on this, they may advise on the quality and validity of information of various sources. By thus positioning themselves, they will be able to play their role as key information providers in a changing society.

Statistical methods for transverse beam position diagnostics with higher order modes in third harmonic 3.9 GHz superconducting accelerating cavities at FLASH

Energy Technology Data Exchange (ETDEWEB)

Zhang, Pei, E-mail: pei.zhang@desy.de [School of Physics and Astronomy, The University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom); Deutsches Elektronen-Synchrotron (DESY), Notkestraße 85, D-22607 Hamburg (Germany); Cockcroft Institute of Science and Technology, Daresbury WA4 4AD (United Kingdom); Baboi, Nicoleta [Deutsches Elektronen-Synchrotron (DESY), Notkestraße 85, D-22607 Hamburg (Germany); Jones, Roger M. [School of Physics and Astronomy, The University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom); Cockcroft Institute of Science and Technology, Daresbury WA4 4AD (United Kingdom)

2014-01-11

Beam-excited higher order modes (HOMs) can be used to provide beam diagnostics. Here we focus on 3.9 GHz superconducting accelerating cavities. In particular we study dipole mode excitation and its application to beam position determinations. In order to extract beam position information, linear regression can be used. Due to a large number of sampling points in the waveforms, statistical methods are used to effectively reduce the dimension of the system, such as singular value decomposition (SVD) and k-means clustering. These are compared with the direct linear regression (DLR) on the entire waveforms. A cross-validation technique is used to study the sample independent precisions of the position predictions given by these three methods. A RMS prediction error in the beam position of approximately 50 μm can be achieved by DLR and SVD, while k-means clustering suggests 70 μm.

Low statistical power in biomedical science: a review of three human research domains

Science.gov (United States)

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

The effects of local street network characteristics on the positional accuracy of automated geocoding for geographic health studies

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Zimmerman Dale L

2010-02-01

Full Text Available Abstract Background Automated geocoding of patient addresses for the purpose of conducting spatial epidemiologic studies results in positional errors. It is well documented that errors tend to be larger in rural areas than in cities, but possible effects of local characteristics of the street network, such as street intersection density and street length, on errors have not yet been documented. Our study quantifies effects of these local street network characteristics on the means and the entire probability distributions of positional errors, using regression methods and tolerance intervals/regions, for more than 6000 geocoded patient addresses from an Iowa county. Results Positional errors were determined for 6376 addresses in Carroll County, Iowa, as the vector difference between each 100%-matched automated geocode and its ground-truthed location. Mean positional error magnitude was inversely related to proximate street intersection density. This effect was statistically significant for both rural and municipal addresses, but more so for the former. Also, the effect of street segment length on geocoding accuracy was statistically significant for municipal, but not rural, addresses; for municipal addresses mean error magnitude increased with length. Conclusion Local street network characteristics may have statistically significant effects on geocoding accuracy in some places, but not others. Even in those locales where their effects are statistically significant, street network characteristics may explain a relatively small portion of the variability among geocoding errors. It appears that additional factors besides rurality and local street network characteristics affect accuracy in general.

A scan statistic to extract causal gene clusters from case-control genome-wide rare CNV data

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Scherer Stephen W

2011-05-01

Full Text Available Abstract Background Several statistical tests have been developed for analyzing genome-wide association data by incorporating gene pathway information in terms of gene sets. Using these methods, hundreds of gene sets are typically tested, and the tested gene sets often overlap. This overlapping greatly increases the probability of generating false positives, and the results obtained are difficult to interpret, particularly when many gene sets show statistical significance. Results We propose a flexible statistical framework to circumvent these problems. Inspired by spatial scan statistics for detecting clustering of disease occurrence in the field of epidemiology, we developed a scan statistic to extract disease-associated gene clusters from a whole gene pathway. Extracting one or a few significant gene clusters from a global pathway limits the overall false positive probability, which results in increased statistical power, and facilitates the interpretation of test results. In the present study, we applied our method to genome-wide association data for rare copy-number variations, which have been strongly implicated in common diseases. Application of our method to a simulated dataset demonstrated the high accuracy of this method in detecting disease-associated gene clusters in a whole gene pathway. Conclusions The scan statistic approach proposed here shows a high level of accuracy in detecting gene clusters in a whole gene pathway. This study has provided a sound statistical framework for analyzing genome-wide rare CNV data by incorporating topological information on the gene pathway.

Nursing students' attitudes toward statistics: Effect of a biostatistics course and association with examination performance.

Science.gov (United States)

Kiekkas, Panagiotis; Panagiotarou, Aliki; Malja, Alvaro; Tahirai, Daniela; Zykai, Rountina; Bakalis, Nick; Stefanopoulos, Nikolaos

2015-12-01

Although statistical knowledge and skills are necessary for promoting evidence-based practice, health sciences students have expressed anxiety about statistics courses, which may hinder their learning of statistical concepts. To evaluate the effects of a biostatistics course on nursing students' attitudes toward statistics and to explore the association between these attitudes and their performance in the course examination. One-group quasi-experimental pre-test/post-test design. Undergraduate nursing students of the fifth or higher semester of studies, who attended a biostatistics course. Participants were asked to complete the pre-test and post-test forms of The Survey of Attitudes Toward Statistics (SATS)-36 scale at the beginning and end of the course respectively. Pre-test and post-test scale scores were compared, while correlations between post-test scores and participants' examination performance were estimated. Among 156 participants, post-test scores of the overall SATS-36 scale and of the Affect, Cognitive Competence, Interest and Effort components were significantly higher than pre-test ones, indicating that the course was followed by more positive attitudes toward statistics. Among 104 students who participated in the examination, higher post-test scores of the overall SATS-36 scale and of the Affect, Difficulty, Interest and Effort components were significantly but weakly correlated with higher examination performance. Students' attitudes toward statistics can be improved through appropriate biostatistics courses, while positive attitudes contribute to higher course achievements and possibly to improved statistical skills in later professional life. Copyright © 2015 Elsevier Ltd. All rights reserved.

Seroprevalence of Epstein-Barr virus among HIV positive patients moreover and its association with CD4 positive lymphocyte count.

Directory of Open Access Journals (Sweden)

Alireza Abdollahi

2014-12-01

Full Text Available Opportunistic infections are the leading cause of hospitalization and morbidity in human immunodeficiency virus (HIV positive patients and are the most common cause of death between them. We aimed to measure IgG antibody against EBV viral capsid antigen (EBV-VCA IgG to determine the seroprevalence of this infection in HIV-positive population. A case-control study between September 2011 and October 2012 was conducted in a teaching hospital enrolling 114 HIV-positive patients as case group and 114 healthy individuals as control with similar age and sex. Enzyme-linked immunosurbant assay (ELISA technique was used for determination of EBV-VAC IgG in obtained samples. Of 114 serum samples obtained from HIV-positive patients, 103 (90.4% samples were found positive for EBV-VCA IgG antibody. There was no significant difference in seroprevalence of EBV VCA IgG antibody between patients received antiretroviral therapy and naive patients (91.5% vs. 87.5%, P>0.05. There was no statistically significant difference in EBV-VCA IgG seroprevalence between three groups of CD4+ in HIV positive group. In conclusion current study showed that seroprevalence of EBV in HIV-positive patients is higher than HIV-negative healthy participants; however, administration of HAART and CD4+ lymphocyte count did not reveal a significant effect in seroprevalence of EBV. Due to the significance of this virus in mortality and morbidity and causing certain malignancies in patients with AIDS, these patients are strongly recommended to be tested for this virus.

Methods and statistics for combining motif match scores.

Science.gov (United States)

Bailey, T L; Gribskov, M

1998-01-01

Position-specific scoring matrices are useful for representing and searching for protein sequence motifs. A sequence family can often be described by a group of one or more motifs, and an effective search must combine the scores for matching a sequence to each of the motifs in the group. We describe three methods for combining match scores and estimating the statistical significance of the combined scores and evaluate the search quality (classification accuracy) and the accuracy of the estimate of statistical significance of each. The three methods are: 1) sum of scores, 2) sum of reduced variates, 3) product of score p-values. We show that method 3) is superior to the other two methods in both regards, and that combining motif scores indeed gives better search accuracy. The MAST sequence homology search algorithm utilizing the product of p-values scoring method is available for interactive use and downloading at URL http:/(/)www.sdsc.edu/MEME.

Supine or prone position for mini-PNL procedure: does it matter.

Science.gov (United States)

Tokatlı, Zafer; Gokce, Mehmet Ilker; Süer, Evren; Sağlam, Remzi

2015-06-01

In this study it is aimed to compare the success and complication rates of mini-PNL procedure in supine and prone positions. In this retrospective study data of 180 patients treated with MPNL either in supine (n = 54) or prone (n = 126) positions between May 2009 and August 2014 was investigated. Success was defined as no visible stones >2 mm. Perioperative complications were classified using the modified Clavien system. Groups were compared with Chi square test or Student t test and for statistical significance p value of 0.05 was accepted. Mean age of the population was 42.5 ± 8.2 years and mean stone size was 23.9 ± 4.1 mm. The two groups were similar with regard to demographic characteristics and stone related characteristics except the ASA status. Success rates of the supine and prone groups were 85.1 and 87.3%, respectively (p = 0.701). No statistically significant differences in terms of complications were observed. Mean operative time was the only parameter different between the two groups (55 vs 82 min, p = 0.001). Supine position for PNL seems to be promising and the complication and success rates are shown to be similar to the prone position with MPNL technique. The only significant benefit of this technique is shorter operative time.

Clinical significance of orthostatic dizziness in the diagnosis of benign paroxysmal positional vertigo and orthostatic intolerance.

Science.gov (United States)

Jeon, Eun-Ju; Park, Yong-Soo; Park, Shi-Nae; Park, Kyoung-Ho; Kim, Dong-Hyun; Nam, In-Chul; Chang, Ki-Hong

2013-01-01

Orthostatic dizziness (OD) and positional dizziness (PD) are considerably common conditions in dizziness clinic, whereas those two conditions are not clearly separated. We aimed to evaluate the clinical significance of simple OD and OD combined with PD for the diagnosis of benign paroxysmal positional vertigo (BPPV) and orthostatic intolerance (OI). Patients presenting with OD (n=102) were divided into two groups according to their symptoms: group PO, presenting with PD as well as OD; group O, presenting with OD. A thorough medical history, physical examination, and vestibular function tests were performed to identify the etiology of the dizziness. Orthostatic vital sign measurement (OVSM) was used to diagnose OI. The majority of patients were in group PO (87.3%). BPPV was the most common cause of OD for entire patients (36.3%) and group PO (37.1%), while OI was most common etiology for group O (38.5%). Total of 17 (16.7%) OI patients were identified by OVSM test. Orthostatic hypotension (n=10) was most frequently found, followed by orthostatic hypertension (n=5), and orthostatic tachycardia (n=2). Group O showed significantly higher percentage (38.5%) of OI than group PO (13.5%) (P=0.039). It is suggested that orthostatic testing such as OVSM or head-up tilt table test should be performed as an initial work up for the patients with simple OD. Positional tests for BPPV should be considered as an essential diagnostic test for patients with OD, even though their dizziness is not associated with PD. Copyright © 2013 Elsevier Inc. All rights reserved.

Positive Selection or Free to Vary? Assessing the Functional Significance of Sequence Change Using Molecular Dynamics.

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Jane R Allison

Full Text Available Evolutionary arms races between pathogens and their hosts may be manifested as selection for rapid evolutionary change of key genes, and are sometimes detectable through sequence-level analyses. In the case of protein-coding genes, such analyses frequently predict that specific codons are under positive selection. However, detecting positive selection can be non-trivial, and false positive predictions are a common concern in such analyses. It is therefore helpful to place such predictions within a structural and functional context. Here, we focus on the p19 protein from tombusviruses. P19 is a homodimer that sequesters siRNAs, thereby preventing the host RNAi machinery from shutting down viral infection. Sequence analysis of the p19 gene is complicated by the fact that it is constrained at the sequence level by overprinting of a viral movement protein gene. Using homology modeling, in silico mutation and molecular dynamics simulations, we assess how non-synonymous changes to two residues involved in forming the dimer interface-one invariant, and one predicted to be under positive selection-impact molecular function. Interestingly, we find that both observed variation and potential variation (where a non-synonymous change to p19 would be synonymous for the overprinted movement protein does not significantly impact protein structure or RNA binding. Consequently, while several methods identify residues at the dimer interface as being under positive selection, MD results suggest they are functionally indistinguishable from a site that is free to vary. Our analyses serve as a caveat to using sequence-level analyses in isolation to detect and assess positive selection, and emphasize the importance of also accounting for how non-synonymous changes impact structure and function.

Elementary Statistics Tables

CERN Document Server

Neave, Henry R

2012-01-01

This book, designed for students taking a basic introductory course in statistical analysis, is far more than just a book of tables. Each table is accompanied by a careful but concise explanation and useful worked examples. Requiring little mathematical background, Elementary Statistics Tables is thus not just a reference book but a positive and user-friendly teaching and learning aid. The new edition contains a new and comprehensive "teach-yourself" section on a simple but powerful approach, now well-known in parts of industry but less so in academia, to analysing and interpreting process dat

[Delirium in stroke patients : Critical analysis of statistical procedures for the identification of risk factors].

Science.gov (United States)

Nydahl, P; Margraf, N G; Ewers, A

2017-04-01

Delirium is a relevant complication following an acute stroke. It is a multifactor occurrence with numerous interacting risk factors that alternately influence each other. The risk factors of delirium in stroke patients are often based on limited clinical studies. The statistical procedures and clinical relevance of delirium related risk factors in adult stroke patients should therefore be questioned. This secondary analysis includes clinically relevant studies that give evidence for the clinical relevance and statistical significance of delirium-associated risk factors in stroke patients. The quality of the reporting of regression analyses was assessed using Ottenbacher's quality criteria. The delirium-associated risk factors identified were examined with regard to statistical significance using the Bonferroni method of multiple testing for forming incorrect positive hypotheses. This was followed by a literature-based discussion on clinical relevance. Nine clinical studies were included. None of the studies fulfilled all the prerequisites and assumptions given for the reporting of regression analyses according to Ottenbacher. Of the 108 delirium-associated risk factors, a total of 48 (44.4%) were significant, whereby a total of 28 (58.3%) were false positive after Bonferroni correction. Following a literature-based discussion on clinical relevance, the assumption of statistical significance and clinical relevance could be found for only four risk factors (dementia or cognitive impairment, total anterior infarct, severe infarct and infections). The statistical procedures used in the existing literature are questionable, as are their results. A post-hoc analysis and critical appraisal reduced the number of possible delirium-associated risk factors to just a few clinically relevant factors.

Clinical significance of isolated anti-HBc positivity in cases of chronic liver disease in New Delhi, India

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Manisha Jain

2009-01-01

Full Text Available Background: The presence of anti-HBc IgG in the absence of HBsAg is usually indicative of a past self-limiting HBV infection. But it is frequently associated with co-infection with HCV which can worsen the existing status of chronic liver disease (CLD. Objectives: The present study was planned to evaluate the significance of isolated HBc IgG positivity in patients of CLD and look for the presence of HCV co-infection in such patients. Methods: Clinical profiles and biochemical tests were done for all the 77 CLD cases included in the study. Blood samples were taken from these patients and tested by the commercially available EIA for the presence of HBsAg, anti-HBc IgG, anti-HBs and anti-HCV. HBV DNA was detected by amplifying the surface region in all the cases. Results: Isolated anti-HBc IgG positivity defined as the presence of anti-HBc IgG in absence of any other serological markers of HBV infection was detected in 28 patients . Out of 64 patients positive for anti-HBc IgG 36 had the markers of HBV, either HBsAg, HBV DNA or anti-HBs alone or in combination. There was a significant association between isolated anti-HBc IgG positivity and HCV co-infection. Conclusion: Anti-HBc IgG should be tested in all patients with CLD as it is frequently the only marker of HBV infection in such patients and they should be monitored closely as such patients can develop CLD. Presence of co-infection with HCV should be actively searched for in such patients.

The presence and prognostic significance of human papillomavirus in squamous cell carcinoma of the larynx.

Science.gov (United States)

Erkul, Evren; Yilmaz, Ismail; Narli, Gizem; Babayigit, Mustafa Alparslan; Gungor, Atila; Demirel, Dilaver

2017-07-01

The aim of the present study was to evaluate the role of HPV in laryngeal squamous cell carcinoma and correlate it with patients' clinicopathological data. In total, 78 laryngeal squamous cell carcinoma patients enrolled in this study. The presence of genotype-specific HPV DNA was evaluated using Genotyping Assay in formalin-fixed paraffin-embedded tissue which was diagnosed between 2005 and 2015. All samples were also evaluated for p16 immunohistochemical staining. HPV DNA and p16 status were assessed in terms of location, smoking, alcohol consumption, lymph node status, tumor stage, overall survival, disease-free survival, perineural invasion, and vascular invasion retrospectively. Five test samples were excluded from the study due to inadequate deoxyribonucleic acid purity. HPV DNA was detected in 19 of 73 (26.02%) in patients with laryngeal squamous cell carcinoma. Human papilloma virus genotyping revealed double human papilloma virus in one case (types 16 and 59) and HPV 16 in the remaining cases. Although HPV-positive cases showed slightly better 3 years survival than HPV-negative ones, this finding was not statistically significant (overall survival p = 0.417, HPV positive: 92.3%, HPV negative: 81.4%, and disease-free survival p = 0.526, HPV positive: 93.8%, HPV negative: 80.9%). The presence of HPV DNA was not significantly associated with any clinicopathological features (p > 0.05). Among 73 patients, only 4 had an immunohistochemical staining of p16 and these patients were also HPV DNA 16 positive. Although our study results revealed a slightly better survival in patients with HPV DNA positivity for HPV 16 compared to the negative ones, the difference was not statistically significant. However, an increasing rate in especially high-risk-type HPV-16 prevalence in laryngeal squamous cell carcinoma by RT-PCR method was observed compared to our previous study. Although the presence of HPV in laryngeal SCCs seems to be associated with slightly better

Statistical model selection with “Big Data”

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Jurgen A. Doornik

2015-12-01

Full Text Available Big Data offer potential benefits for statistical modelling, but confront problems including an excess of false positives, mistaking correlations for causes, ignoring sampling biases and selecting by inappropriate methods. We consider the many important requirements when searching for a data-based relationship using Big Data, and the possible role of Autometrics in that context. Paramount considerations include embedding relationships in general initial models, possibly restricting the number of variables to be selected over by non-statistical criteria (the formulation problem, using good quality data on all variables, analyzed with tight significance levels by a powerful selection procedure, retaining available theory insights (the selection problem while testing for relationships being well specified and invariant to shifts in explanatory variables (the evaluation problem, using a viable approach that resolves the computational problem of immense numbers of possible models.

Position-momentum uncertainty relations in the presence of quantum memory

DEFF Research Database (Denmark)

Furrer, Fabian; Berta, Mario; Tomamichel, Marco

2014-01-01

A prominent formulation of the uncertainty principle identifies the fundamental quantum feature that no particle may be prepared with certain outcomes for both position and momentum measurements. Often the statistical uncertainties are thereby measured in terms of entropies providing a clear oper....... As an illustration, we evaluate the uncertainty relations for position and momentum measurements, which is operationally significant in that it implies security of a quantum key distribution scheme based on homodyne detection of squeezed Gaussian states....

Activity in ventromedial prefrontal cortex during self-related processing: positive subjective value or personal significance?

Science.gov (United States)

Kim, Kyungmi; Johnson, Marcia K

2015-04-01

Well-being and subjective experience of a coherent world depend on our sense of 'self' and relations between the self and the environment (e.g. people, objects and ideas). The ventromedial prefrontal cortex (vMPFC) is involved in self-related processing, and disrupted vMPFC activity is associated with disruptions of emotional/social functioning (e.g. depression and autism). Clarifying precise function(s) of vMPFC in self-related processing is an area of active investigation. In this study, we sought to more specifically characterize the function of vMPFC in self-related processing, focusing on two alternative accounts: (i) assignment of positive subjective value to self-related information and (ii) assignment of personal significance to self-related information. During functional magnetic resonance imaging (fMRI), participants imagined owning objects associated with either their perceived ingroup or outgroup. We found that for ingroup-associated objects, vMPFC showed greater activity for objects with increased than decreased post-ownership preference. In contrast, for outgroup-associated objects, vMPFC showed greater activity for objects with decreased than increased post-ownership preference. Our findings support the idea that the function of vMPFC in self-related processing may not be to represent/evaluate the 'positivity' or absolute preference of self-related information but to assign personal significance to it based on its meaning/function for the self. © The Author (2014). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

Statistical significance approximation in local trend analysis of high-throughput time-series data using the theory of Markov chains.

Science.gov (United States)

Xia, Li C; Ai, Dongmei; Cram, Jacob A; Liang, Xiaoyi; Fuhrman, Jed A; Sun, Fengzhu

2015-09-21

Local trend (i.e. shape) analysis of time series data reveals co-changing patterns in dynamics of biological systems. However, slow permutation procedures to evaluate the statistical significance of local trend scores have limited its applications to high-throughput time series data analysis, e.g., data from the next generation sequencing technology based studies. By extending the theories for the tail probability of the range of sum of Markovian random variables, we propose formulae for approximating the statistical significance of local trend scores. Using simulations and real data, we show that the approximate p-value is close to that obtained using a large number of permutations (starting at time points >20 with no delay and >30 with delay of at most three time steps) in that the non-zero decimals of the p-values obtained by the approximation and the permutations are mostly the same when the approximate p-value is less than 0.05. In addition, the approximate p-value is slightly larger than that based on permutations making hypothesis testing based on the approximate p-value conservative. The approximation enables efficient calculation of p-values for pairwise local trend analysis, making large scale all-versus-all comparisons possible. We also propose a hybrid approach by integrating the approximation and permutations to obtain accurate p-values for significantly associated pairs. We further demonstrate its use with the analysis of the Polymouth Marine Laboratory (PML) microbial community time series from high-throughput sequencing data and found interesting organism co-occurrence dynamic patterns. The software tool is integrated into the eLSA software package that now provides accelerated local trend and similarity analysis pipelines for time series data. The package is freely available from the eLSA website: http://bitbucket.org/charade/elsa.

Test the Overall Significance of p-values by Using Joint Tail Probability of Ordered p-values as Test Statistic

OpenAIRE

Fang, Yongxiang; Wit, Ernst

2008-01-01

Fisher’s combined probability test is the most commonly used method to test the overall significance of a set independent p-values. However, it is very obviously that Fisher’s statistic is more sensitive to smaller p-values than to larger p-value and a small p-value may overrule the other p-values and decide the test result. This is, in some cases, viewed as a flaw. In order to overcome this flaw and improve the power of the test, the joint tail probability of a set p-values is proposed as a ...

ϕ-statistically quasi Cauchy sequences

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Bipan Hazarika

2016-04-01

Full Text Available Let P denote the space whose elements are finite sets of distinct positive integers. Given any element σ of P, we denote by p(σ the sequence {pn(σ} such that pn(σ=1 for n ∈ σ and pn(σ=0 otherwise. Further Ps={σ∈P:∑n=1∞pn(σ≤s}, i.e. Ps is the set of those σ whose support has cardinality at most s. Let (ϕn be a non-decreasing sequence of positive integers such that nϕn+1≤(n+1ϕn for all n∈N and the class of all sequences (ϕn is denoted by Φ. Let E⊆N. The number δϕ(E=lims→∞1ϕs|{k∈σ,σ∈Ps:k∈E}| is said to be the ϕ-density of E. A sequence (xn of points in R is ϕ-statistically convergent (or Sϕ-convergent to a real number ℓ for every ε > 0 if the set {n∈N:|xn−ℓ|≥ɛ} has ϕ-density zero. We introduce ϕ-statistically ward continuity of a real function. A real function is ϕ-statistically ward continuous if it preserves ϕ-statistically quasi Cauchy sequences where a sequence (xn is called to be ϕ-statistically quasi Cauchy (or Sϕ-quasi Cauchy when (Δxn=(xn+1−xn is ϕ-statistically convergent to 0. i.e. a sequence (xn of points in R is called ϕ-statistically quasi Cauchy (or Sϕ-quasi Cauchy for every ε > 0 if {n∈N:|xn+1−xn|≥ɛ} has ϕ-density zero. Also we introduce the concept of ϕ-statistically ward compactness and obtain results related to ϕ-statistically ward continuity, ϕ-statistically ward compactness, statistically ward continuity, ward continuity, ward compactness, ordinary compactness, uniform continuity, ordinary continuity, δ-ward continuity, and slowly oscillating continuity.

Schoolwide Positive Behavior Supports and Students with Significant Disabilities: Where Are We?

Science.gov (United States)

Kurth, Jennifer A.; Enyart, Matt

2016-01-01

Although the number of schools implementing schoolwide positive behavior supports (SWPBS) has increased dramatically, the inclusion of students with severe disabilities in these efforts remains negligible. This article describes the evolution of positive behavior intervention and supports into the SWPBS approach used in many schools today,…

Proper interpretation of chronic toxicity studies and their statistics: A critique of "Which level of evidence does the US National Toxicology Program provide? Statistical considerations using the Technical Report 578 on Ginkgo biloba as an example".

Science.gov (United States)

Kissling, Grace E; Haseman, Joseph K; Zeiger, Errol

2015-09-02

A recent article by Gaus (2014) demonstrates a serious misunderstanding of the NTP's statistical analysis and interpretation of rodent carcinogenicity data as reported in Technical Report 578 (Ginkgo biloba) (NTP, 2013), as well as a failure to acknowledge the abundant literature on false positive rates in rodent carcinogenicity studies. The NTP reported Ginkgo biloba extract to be carcinogenic in mice and rats. Gaus claims that, in this study, 4800 statistical comparisons were possible, and that 209 of them were statistically significant (p<0.05) compared with 240 (4800×0.05) expected by chance alone; thus, the carcinogenicity of Ginkgo biloba extract cannot be definitively established. However, his assumptions and calculations are flawed since he incorrectly assumes that the NTP uses no correction for multiple comparisons, and that significance tests for discrete data operate at exactly the nominal level. He also misrepresents the NTP's decision making process, overstates the number of statistical comparisons made, and ignores the fact that the mouse liver tumor effects were so striking (e.g., p<0.0000000000001) that it is virtually impossible that they could be false positive outcomes. Gaus' conclusion that such obvious responses merely "generate a hypothesis" rather than demonstrate a real carcinogenic effect has no scientific credibility. Moreover, his claims regarding the high frequency of false positive outcomes in carcinogenicity studies are misleading because of his methodological misconceptions and errors. Published by Elsevier Ireland Ltd.

Effects of Fatty Acids at Different Positions in the Triglycerides on Cholesterol Levels

International Nuclear Information System (INIS)

Teh, S.S.; Voon, P.T.; Ng, Y.T.; Ong, S.H.; Augustine, S.H.O.; Choo, Y.M.

2016-01-01

Previous studies established a series of regression equations for predicting the risk factor effects from serum cholesterol concentrations. However, the degree of saturation was solely based on total fatty acid composition in triglycerides. Our article is focused on the relationships between the published human nutrition studies and predicted values of serum cholesterol levels based on total fatty acid compositions and at sn-2 position in triglycerides. Twenty-two published human nutrition studies were chosen to assess the effects of palm olein, olive oil, cocoa butter, sunflower seed oil, corn oil, soyabean oil, grape seed oil, groundnut oil and rice bran oil diets on serum cholesterol levels. There were no statistically significant differences between the predicted values of serum cholesterol levels based on fatty acids at sn-2 position and the published human nutrition studies as proven by the statistical analyses with p values more than 0.05. In contrast, there were statistically significant differences between the predicted values of serum cholesterol levels based on total fatty acids and the published human nutritional studies with p values less than 0.05. Fatty acids at sn-2 position appear to influence the cholesterol levels rather than total fatty acids of the triglyceride. (author)

Decreasing the effective radiation dose in pediatric craniofacial CT by changing head position

International Nuclear Information System (INIS)

Didier, Ryne A.; Kuang, Anna A.; Schwartz, Daniel L.; Selden, Nathan R.; Stevens, Donna M.; Bardo, Dianna M.E.

2010-01-01

Children are exposed to ionizing radiation during pre- and post-operative evaluation for craniofacial surgery. The primary purpose of the study was to decrease effective radiation dose while preserving the diagnostic quality of the study. In this prospective study 49 children were positioned during craniofacial CT (CFCT) imaging with their neck fully extended into an exaggerated sniff position, parallel to the CT gantry, to eliminate the majority of the cervical spine and the thyroid gland from radiation exposure. Image-quality and effective radiation dose comparisons were made retrospectively in age-matched controls (n = 49). When compared to CT scans reviewed retrospectively, the prospective examinations showed a statistically significant decrease in z-axis length by 16% (P < 0.0001) and delivered a reduced effective radiation dose by 18% (P < 0.0001). The subjective diagnostic quality of the exams performed in the prospective arm was maintained despite a slight decrease in the quality of the brain windows. There was statistically significant improvement in the quality of the bone windows and three-dimensional reconstructed images. Altering the position of the head by extending the neck during pediatric craniofacial CT imaging statistically reduces the effective radiation dose while maintaining the diagnostic quality of the images. (orig.)

Changes in retinal nerve fiber layer thickness after spinal surgery in the prone position: a prospective study

Directory of Open Access Journals (Sweden)

Baran Gencer

2015-02-01

Full Text Available BACKGROUND AND OBJECTIVES: Changes in ocular perfusion play an important role in the pathogenesis of ischemic optic neuropathy. Ocular perfusion pressure is equal to mean arterial pressure minus intraocular pressure. The aim of this study was to evaluate the changes in the intraocular pressure and the retinal nerve fiber layer thickness in patients undergoing spinal surgery in the prone position. METHODS: This prospective study included 30 patients undergoing spinal surgery. Retinal nerve fiber layer thickness were measured one day before and after the surgery by using optical coherence tomography. Intraocular pressure was measured by tonopen six times at different position and time-duration: supine position (baseline; 10 min after intubation (Supine 1; 10 (Prone 1, 60 (Prone 2, 120 (Prone 3 min after prone position; and just after postoperative supine position (Supine 2. RESULTS: Our study involved 10 male and 20 female patients with the median age of 57 years. When postoperative retinal nerve fiber layer thickness measurements were compared with preoperative values, a statistically significant thinning was observed in inferior and nasal quadrants (p = 0.009 and p = 0.003, respectively. We observed a statistically significant intraocular pressure decrease in Supine 1 and an increase in both Prone 2 and Prone 3 when compared to the baseline. Mean arterial pressure and ocular perfusion pressure were found to be significantly lower in Prone 1, Prone 2 and Prone 3, when compared with the baseline. CONCLUSIONS: Our study has shown increase in intraocular pressure during spinal surgery in prone position. A statistically significant retinal nerve fiber layer thickness thinning was seen in inferior and nasal quadrants one day after the spinal surgery.

Association of depression with social support and self-esteem among HIV positives.

Science.gov (United States)

Jagannath, Vinita; Unnikrishnan, B; Hegde, Supriya; Ramapuram, John T; Rao, S; Achappa, B; Madi, D; Kotian, M S

2011-12-01

Depression in Human Immunodeficiency Virus (HIV) positives has implications such as poor drug compliance, lower quality of life, faster progression to full blown Acquired Immunodeficiency Syndrome (AIDS) and higher mortality. To assess depression, social support and self-esteem in HIV positives and to find out the association of depression with social support and self-esteem among HIV positive patients. Kasturba Medical College (KMC) Hospital, a tertiary care hospital, Mangalore, India and cross-sectional design. Study constituted of 105 HIV positive subjects; depression was assessed using BDI (Beck depression inventory), social support was assessed using Lubben social network scale and self-esteem was assessed using Rosenberg self-esteem scale. Kappa statistics was used to measure the agreement of depression assessed by BDI with clinical diagnosis of depression. Logistic regression analyses were done to find out predictors of depression among HIV positives. All analyses were conducted using Statistical Package for Social Sciences (SPSS) version 11.5. Depression was found to be present in 43.8% of HIV positives. Among the study subjects, 10.5% had high risk for isolation and low self-esteem was found only among 5.7%. In univariate analysis both gender and self-esteem were significantly associated with depression whereas in multivariate analysis only self-esteem was found to be significantly associated with depression. The present study shows a high prevalence of depression in HIV positive patients along with the importance of self-esteem. Copyright © 2011 Elsevier B.V. All rights reserved.

Statistical reviewers improve reporting in biomedical articles: a randomized trial.

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Erik Cobo

2007-03-01

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.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.

Prognostic and clinicopathological significance of Cacna2d1 expression in epithelial ovarian cancers: a retrospective study

Science.gov (United States)

Yu, Dandan; Holm, Ruth; Goscinski, Mariusz Adam; Trope, Claes G; Nesland, Jahn M; Suo, Zhenhe

2016-01-01

Ovarian cancer is the most lethal gynecologic malignancy, in which cancer stem cells (CSC) have been reported to be the driving force of relapse and therapy-resistance. It is therefore important to explore CSC markers in ovarian cancer. This project aimed to explore the correlation between the expression of potential CSC maker Cacna2d1 and clinicopathological parameters in 238 epithelial ovarian cancer (EOC) samples. Immunohistochemically, positive Cacna2d1 expression was observed in 83.6% (199/238) of the EOC tumors, among which 107 tumors (44.9%) were highly positive and 92 (38.7%) tumors were weakly positive for the Cacna2d1 protein expression. Among the 158 serous carcinomas, the Cacna2d1 positivity was 148 (93.7%), in which 88 (55.7%) were highly positive, and 60 (38.0%) were weakly positive for the Cacna2d1 protein expression. Most strikingly, the Cacna2d1 was specifically expressed in the infiltration front areas of the EOC tumors. Statistical analyses showed that positive expression of Cacna2d1 was significantly associated with advanced FIGO stage (P<0.001), histological subtype (P=0.017) and tumor differentiation (P=0.015). Positive Cacna2d1 protein expression was significantly associated with poor overall survival (OS) and shorter progression free survival (PFS) in both total EOCs and serous carcinomas, although multivariate analyses did not reach statistical significance. In summary, our results suggest Cacna2d1 protein may play a crucial role in promoting aggressive EOC behavior and progression, and Cacna2d1 may serve as a novel predictive prognostic marker and a potential target for therapeutic intervention in EOCs. PMID:27725913

Distortion-product otoacoustic emissions: body position effects with simultaneous presentation of tone pairs

Directory of Open Access Journals (Sweden)

Samuel R. Atcherson

2011-11-01

Full Text Available This study examined the effect of three different body positions on distortion-product otoacoustic emission (DPOAE amplitude and noise levels with multiple primary tone pairs simultaneously-presented to 36 normal-hearing female human adults. Other studies have demonstrated that the simultaneously presented tone pairs method shows clinical promise as a screener, but the sequential method remains in widespread clinical use. Postural changes have been suggested to have an effect not only on DPOAEs, but also transient-evoked OAEs and stimulus- frequency OAEs. DPOAE amplitude and noise levels were recorded in seated, supine, and side-lying positions to the following order of simultaneously-presented tone pairs relative to the f2 frequencies: 1187, 2375, and 4812 Hz; 1500, 3000, and 6062 Hz; and 1875, 3812, and 7625 Hz. No DPOAE could be detected reliably at 7625 Hz as result of poor signal-to-noise ratio. For remaining DPOAEs, statistical analyses revealed that amplitudes were not significantly different among the three body positions. However, at 1500 Hz and below, body position did have a statistically significant effect on noise levels though they are likely clinically negligible. Except at 7625 Hz, results suggest that DPOAEs recorded using a simultaneously presented tone pairs appear to be comparably recorded regardless of an individual’s body position.

After statistics reform : Should we still teach significance testing?

NARCIS (Netherlands)

A. Hak (Tony)

2014-01-01

textabstractIn the longer term null hypothesis significance testing (NHST) will disappear because p- values are not informative and not replicable. Should we continue to teach in the future the procedures of then abolished routines (i.e., NHST)? Three arguments are discussed for not teaching NHST in

Comparison of pulsar positions from timing and very long baseline astrometry

Science.gov (United States)

Wang, J. B.; Coles, W. A.; Hobbs, G.; Shannon, R. M.; Manchester, R. N.; Kerr, M.; Yuan, J. P.; Wang, N.; Bailes, M.; Bhat, N. D. R.; Dai, S.; Dempsey, J.; Keith, M. J.; Lasky, P. D.; Levin, Y.; Osłowski, S.; Ravi, V.; Reardon, D. J.; Rosado, P. A.; Russell, C. J.; Spiewak, R.; van Straten, W.; Toomey, L.; Wen, L.; You, X.-P.; Zhu, X.-J.

2017-07-01

Pulsar positions can be measured with high precision using both pulsar timing methods and very long baseline interferometry (VLBI). Pulsar timing positions are referenced to a solar-system ephemeris, whereas VLBI positions are referenced to distant quasars. Here, we compare pulsar positions from published VLBI measurements with those obtained from pulsar timing data from the Nanshan and Parkes radio telescopes in order to relate the two reference frames. We find that the timing positions differ significantly from the VLBI positions (and also differ between different ephemerides). A statistically significant change in the obliquity of the ecliptic of 2.16 ± 0.33 mas is found for the JPL ephemeris DE405, but no significant rotation is found in subsequent JPL ephemerides. The accuracy with which we can relate the two frames is limited by the current uncertainties in the VLBI reference source positions and in matching the pulsars to their reference source. Not only do the timing positions depend on the ephemeris used in computing them, but also different segments of the timing data lead to varying position estimates. These variations are mostly common to all ephemerides, but slight changes are seen at the 10 μas level between ephemerides.

Lateral sesamoid position in hallux valgus: correlation with the conventional radiological assessment.

Science.gov (United States)

Agrawal, Yuvraj; Desai, Aravind; Mehta, Jaysheel

2011-12-01

We aimed to quantify the severity of the hallux valgus based on the lateral sesamoid position and to establish a correlation of our simple assessment method with the conventional radiological assessments. We reviewed one hundred and twenty two dorso-plantar weight bearing radiographs of feet. The intermetatarsal and hallux valgus angles were measured by the conventional methods; and the position of lateral sesamoid in relation to first metatarsal neck was assessed by our new and simple method. Significant correlation was noted between intermetatarsal angle and lateral sesamoid position (Rho 0.74, p lateral sesamoid position and hallux valgus angle (Rho 0.56, p lateral sesamoid position is simple, less time consuming and has statistically significant correlation with that of the established conventional radiological measurements. Copyright © 2011 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.

Worry, Intolerance of Uncertainty, and Statistics Anxiety

Science.gov (United States)

Williams, Amanda S.

2013-01-01

Statistics anxiety is a problem for most graduate students. This study investigates the relationship between intolerance of uncertainty, worry, and statistics anxiety. Intolerance of uncertainty was significantly related to worry, and worry was significantly related to three types of statistics anxiety. Six types of statistics anxiety were…

Reducing statistics anxiety and enhancing statistics learning achievement: effectiveness of a one-minute strategy.

Science.gov (United States)

Chiou, Chei-Chang; Wang, Yu-Min; Lee, Li-Tze

2014-08-01

Statistical knowledge is widely used in academia; however, statistics teachers struggle with the issue of how to reduce students' statistics anxiety and enhance students' statistics learning. This study assesses the effectiveness of a "one-minute paper strategy" in reducing students' statistics-related anxiety and in improving students' statistics-related achievement. Participants were 77 undergraduates from two classes enrolled in applied statistics courses. An experiment was implemented according to a pretest/posttest comparison group design. The quasi-experimental design showed that the one-minute paper strategy significantly reduced students' statistics anxiety and improved students' statistics learning achievement. The strategy was a better instructional tool than the textbook exercise for reducing students' statistics anxiety and improving students' statistics achievement.

Evaluation of significantly modified water bodies in Vojvodina by using multivariate statistical techniques

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Vujović Svetlana R.

2013-01-01

Full Text Available This paper illustrates the utility of multivariate statistical techniques for analysis and interpretation of water quality data sets and identification of pollution sources/factors with a view to get better information about the water quality and design of monitoring network for effective management of water resources. Multivariate statistical techniques, such as factor analysis (FA/principal component analysis (PCA and cluster analysis (CA, were applied for the evaluation of variations and for the interpretation of a water quality data set of the natural water bodies obtained during 2010 year of monitoring of 13 parameters at 33 different sites. FA/PCA attempts to explain the correlations between the observations in terms of the underlying factors, which are not directly observable. Factor analysis is applied to physico-chemical parameters of natural water bodies with the aim classification and data summation as well as segmentation of heterogeneous data sets into smaller homogeneous subsets. Factor loadings were categorized as strong and moderate corresponding to the absolute loading values of >0.75, 0.75-0.50, respectively. Four principal factors were obtained with Eigenvalues >1 summing more than 78 % of the total variance in the water data sets, which is adequate to give good prior information regarding data structure. Each factor that is significantly related to specific variables represents a different dimension of water quality. The first factor F1 accounting for 28 % of the total variance and represents the hydrochemical dimension of water quality. The second factor F2 accounting for 18% of the total variance and may be taken factor of water eutrophication. The third factor F3 accounting 17 % of the total variance and represents the influence of point sources of pollution on water quality. The fourth factor F4 accounting 13 % of the total variance and may be taken as an ecological dimension of water quality. Cluster analysis (CA is an

Testing earthquake prediction algorithms: Statistically significant advance prediction of the largest earthquakes in the Circum-Pacific, 1992-1997

Science.gov (United States)

Kossobokov, V.G.; Romashkova, L.L.; Keilis-Borok, V. I.; Healy, J.H.

1999-01-01

Algorithms M8 and MSc (i.e., the Mendocino Scenario) were used in a real-time intermediate-term research prediction of the strongest earthquakes in the Circum-Pacific seismic belt. Predictions are made by M8 first. Then, the areas of alarm are reduced by MSc at the cost that some earthquakes are missed in the second approximation of prediction. In 1992-1997, five earthquakes of magnitude 8 and above occurred in the test area: all of them were predicted by M8 and MSc identified correctly the locations of four of them. The space-time volume of the alarms is 36% and 18%, correspondingly, when estimated with a normalized product measure of empirical distribution of epicenters and uniform time. The statistical significance of the achieved results is beyond 99% both for M8 and MSc. For magnitude 7.5 + , 10 out of 19 earthquakes were predicted by M8 in 40% and five were predicted by M8-MSc in 13% of the total volume considered. This implies a significance level of 81% for M8 and 92% for M8-MSc. The lower significance levels might result from a global change in seismic regime in 1993-1996, when the rate of the largest events has doubled and all of them become exclusively normal or reversed faults. The predictions are fully reproducible; the algorithms M8 and MSc in complete formal definitions were published before we started our experiment [Keilis-Borok, V.I., Kossobokov, V.G., 1990. Premonitory activation of seismic flow: Algorithm M8, Phys. Earth and Planet. Inter. 61, 73-83; Kossobokov, V.G., Keilis-Borok, V.I., Smith, S.W., 1990. Localization of intermediate-term earthquake prediction, J. Geophys. Res., 95, 19763-19772; Healy, J.H., Kossobokov, V.G., Dewey, J.W., 1992. A test to evaluate the earthquake prediction algorithm, M8. U.S. Geol. Surv. OFR 92-401]. M8 is available from the IASPEI Software Library [Healy, J.H., Keilis-Borok, V.I., Lee, W.H.K. (Eds.), 1997. Algorithms for Earthquake Statistics and Prediction, Vol. 6. IASPEI Software Library]. ?? 1999 Elsevier

Significant Association of Streptococcus bovis with Malignant Gastrointestinal Diseases

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Salah Shanan

2011-01-01

Full Text Available Streptococcus bovis is a Gram-positive bacterium causing serious human infections, including endocarditis and bacteremia, and is usually associated with underlying disease. The aims of the current study were to compare prevalence of the bacterium associated with malignant and nonmalignant gastrointestinal diseases and to determine the susceptibility of the isolated strains to different antimicrobial agents. The result showed that the prevalence of S. bovis in stool specimens from patients with malignant or with nonmalignant gastrointestinal diseases was statistically significant. This result may support the idea that there is correlation between S. bovis and the malignant gastrointestinal diseases.

The significance of early post-exercise ST segment normalization.

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Chow, Rudy; Fordyce, Christopher B; Gao, Min; Chan, Sammy; Gin, Kenneth; Bennett, Matthew

2015-01-01

The persistence of ST segment depression in recovery signifies a strongly positive exercise treadmill test (ETT). However, it is unclear if early recovery of ST segments portends a similar prognosis. We sought to determine if persistence of ST depression into recovery correlates with ischemic burden based on myocardial perfusion imaging (MPI). This was a retrospective analysis of 853 consecutive patients referred for exercise MPI at a tertiary academic center over a 24-month period. Patients were stratified into three groups based on the results of the ETT: normal (negative ETT), persistence (positive ETT with >1mm ST segment depression at 1minute in recovery) and early normalization (positive ETT with normalization, while 105 patients met criteria for persistence. The persistence group had a significantly greater SSS (8.48±7.77) than both the early normalization (4.34±4.98, pnormal (4.47±5.31, pnormalization and normal groups were not statistically different and met the prespecified non-inferiority margin (mean difference 0.12, -0.66=lower 95% CI, pnormal and 7.4% of early normalization groups. Among patients with an electrically positive ETT, recovery of ST segment depression within 1minute was associated with a lower SSS than patients with persistence of ST depression beyond 1minute. Furthermore, early ST segment recovery conferred a similar SSS to patients with a negative ETT. These results suggest that among patients evaluated for chest pain with a positive ETT, early recovery of the ST segment during recovery is associated with a significantly less ischemic burden on subsequent MPI and thus may represent a false positive finding in exercise treadmill testing. Copyright © 2015 Elsevier Inc. All rights reserved.

A novel complete-case analysis to determine statistical significance between treatments in an intention-to-treat population of randomized clinical trials involving missing data.

Science.gov (United States)

Liu, Wei; Ding, Jinhui

2018-04-01

The application of the principle of the intention-to-treat (ITT) to the analysis of clinical trials is challenged in the presence of missing outcome data. The consequences of stopping an assigned treatment in a withdrawn subject are unknown. It is difficult to make a single assumption about missing mechanisms for all clinical trials because there are complicated reactions in the human body to drugs due to the presence of complex biological networks, leading to data missing randomly or non-randomly. Currently there is no statistical method that can tell whether a difference between two treatments in the ITT population of a randomized clinical trial with missing data is significant at a pre-specified level. Making no assumptions about the missing mechanisms, we propose a generalized complete-case (GCC) analysis based on the data of completers. An evaluation of the impact of missing data on the ITT analysis reveals that a statistically significant GCC result implies a significant treatment effect in the ITT population at a pre-specified significance level unless, relative to the comparator, the test drug is poisonous to the non-completers as documented in their medical records. Applications of the GCC analysis are illustrated using literature data, and its properties and limits are discussed.

THE SIGNIFICANCE OF INTERCULTURAL COMPETENCE IN CROSS-CULTURAL COMMUNICATION

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Jadranka Zlomislić

2016-12-01

Full Text Available The aim of this study is to explore the influence of education and additional factors influencing students’ awareness of intercultural differences. For the purposes of this research assessment was carried out with regard to their role in promoting cultural awareness and facing cross-cultural challenges posed by unfamiliar cross-cultural contexts. Cultural education is presumed to be a key factor for achieving a significant increase of cultural sensitivity and cultural awareness in order to ensure successful cross-cultural communication and increase mobility of students/working professionals. For this study, it was assumed that the cultural awareness of students increases due to the courses they take and their overall study experience. A special questionnaire was developed for the purposes of this research, and the obtained results were statistically analyzed with the help of descriptive statistics, the non-parametric chi-square test, and the Mann-Whitney test. The research has shown that intercultural competence has a statistically significant positive effect on the readiness of students to participate in study and work programs abroad. Thus, it is mandatory that foreign language competence as well as intercultural competence be a priority of the curriculum if we are to increase the number of highly educated experts who will be capable to compete successfully as students or professionals in all fields and all cultural areas. If we recognize that globalization has made the world a global village, we all need the intercultural competence to successfully live in it.

Assigning Significance in Label-Free Quantitative Proteomics to Include Single-Peptide-Hit Proteins with Low Replicates

OpenAIRE

Li, Qingbo

2010-01-01

When sample replicates are limited in a label-free proteomics experiment, selecting differentially regulated proteins with an assignment of statistical significance remains difficult for proteins with a single-peptide hit or a small fold-change. This paper aims to address this issue. An important component of the approach employed here is to utilize the rule of Minimum number of Permuted Significant Pairings (MPSP) to reduce false positives. The MPSP rule generates permuted sample pairings fr...

Shot Group Statistics for Small Arms Applications

Science.gov (United States)

2017-06-01

if its probability distribution is known with sufficient accuracy, then it can be used to make a sound statistical inference on the unknown... statistical inference on the unknown, population standard deviations of the x and y impact-point positions. The dispersion measures treated in this report...known with sufficient accuracy, then it can be used to make a sound statistical inference on the unknown, population standard deviations of the x and y

cMiCE a high resolution animal PET using continuous LSO with a statistics based positioning scheme

CERN Document Server

Joung Jin Hun; Lewellen, T K

2002-01-01

Objective: Detector designs for small animal scanners are currently dominated by discrete crystal implementations. However, given the small crystal cross-sections required to obtain very high resolution, discrete designs are typically expensive, have low packing fraction, reduced light collection, and are labor intensive to build. To overcome these limitations we have investigated the feasibility of using a continuous miniature crystal element (cMiCE) detector module for high resolution small animal PET applications. Methods: The detector module consists of a single continuous slab of LSO, 25x25 mm sup 2 in exposed cross-section and 4 mm thick, coupled directly to a PS-PMT (Hamamatsu R5900-00-C12). The large area surfaces of the crystal were polished and painted with TiO sub 2 and the short surfaces were left unpolished and painted black. Further, a new statistics based positioning (SBP) algorithm has been implemented to address linearity and edge effect artifacts that are inherent with conventional Anger sty...

The radiographic acromiohumeral interval is affected by arm and radiographic beam position

Energy Technology Data Exchange (ETDEWEB)

Fehringer, Edward V.; Rosipal, Charles E.; Rhodes, David A.; Lauder, Anthony J.; Feschuk, Connie A.; Mormino, Matthew A.; Hartigan, David E. [University of Nebraska Medical Center, Department of Orthopaedic Surgery and Rehabilitation, Omaha, NE (United States); Puumala, Susan E. [Nebraska Medical Center, Department of Preventive and Societal Medicine, Omaha, NE (United States)

2008-06-15

The objective was to determine whether arm and radiographic beam positional changes affect the acromiohumeral interval (AHI) in radiographs of healthy shoulders. Controlling for participant's height and position as well as radiographic beam height and angle, from 30 right shoulders of right-handed males without shoulder problems four antero-posterior (AP) radiographic views each were obtained in defined positions. Three independent, blinded physicians measured the AHI to the nearest millimeter in 120 randomized radiographs. Mean differences between measurements were calculated, along with a 95% confidence interval. Controlling for observer effect, there was a significant difference between AHI measurements on different views (p<0.01). All pair-wise differences were statistically significant after adjusting for multiple comparisons (all p values <0.01). Even in healthy shoulders, small changes in arm position and radiographic beam orientation affect the AHI in radiographs. (orig.)

Comparison between Human Immunodeficiency Virus Positive and Negative Patients with Tuberculosis in Southern Brazil

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Lucélia Henn

1999-05-01

Full Text Available The objective of this study is to determine the different characteristics of human immunodeficiency virus (HIV positive and negative patients treated for tuberculosis (TBC in a tertiary hospital in Southern Brazil. We conducted a retrospective cohort study over a 5-year period, from January 1992 through December 1996. We reviewed medical charts of patients from our institution who received TBC treatment. We reviewed 167 medical charts of patients with confirmed TBC. HIV positivity was detected in 74 patients. There were statistically significant difference between HIV positive and negative patients in sex and age. HIV-infected patients showed significantly more signs of bacteremia than HIV-negative patients. Extra-pulmonary TBC was present respectively in 13 (17.6% and 21 (22.6% HIV positive and negative patients. There was a significant difference between chest radiograph presentation in HIV positive and negative patients. There were significantly lower hematocrit, hemoglobin, leukocyte and lymphocyte levels in HIV-positive compared to HIV-negative patients. Outcome was significantly different in the two groups with a death rate of 36.5% and 10.8% in HIV-positive and in HIV-negative patients. The difference between HIV positive and negative patients may have importance in the diagnosis, management and prognosis of patients with TBC.

The isokinetic strength profile of elite soccer players according to playing position.

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Robert Śliwowski

Full Text Available The aim of this study was to compare isokinetic strength performance profiles in elite soccer players across different field positions. A total of 111 elite international players of Polish Ekstraklasa (the top division in Poland were examined during the 2010-2015 seasons. The players were classified into six positional roles: central defenders (CD, external defenders (ED, central midfielders (CM, external midfielders (EM, forwards (F, and goalkeepers (G. The concentric isokinetic strength (peak torque [PT] of quadriceps and hamstrings, H/Q ratios was calculated for the dominant leg and the non-dominant leg at angular velocity of 1.05 rad ·s-1, whereas to assess isokinetic muscle endurance, the total work [TW] at angular velocity of 4.19 rad ·s-1, was taken into consideration. The results showed that isokinetic strength performance varies significantly among players in different playing positions. The analysis of PT for quadriceps (PT-Q and hamstrings (PT-H generally showed that the goalkeepers and central midfielders had lower strength levels compared to other playing positions. In the case of PT-H and hamstring/quadricep (H/Q peak torque ratios, statistically significant differences were also noted for the legs, where mean values noted for the dominant leg were higher than for the non-dominant leg. For TW for quadriceps (TW-Q and hamstrings (TW-H, statistically significant differences were noted only between playing positions. TW-Q values for goalkeepers were lower than for central defenders and external midfielders. TW-H values for goalkeepers were lower than for central midfielders, central defenders and external midfielders. This study showed that specific functional activity of players in individual positions on the field influences the varied profile of isokinetic strength performance.

The clinical significances of the abnormal expressions of Piwil1 and Piwil2 in colonic adenoma and adenocarcinoma

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Wang HL

2015-05-01

Full Text Available Hai-Ling Wang,1 Bei-Bei Chen,1 Xin-Guang Cao,1 Jin Wang,2 Xiu-Feng Hu,1 Xiao-Qian Mu,1 Xiao-Bing Chen1 1The Affiliated Cancer Hospital of Zhengzhou University, Henan Cancer Hospital, Zhengzhou, People’s Republic of China; 2The First Affiliated Hospital of Zhengzhou University, Zhengzhou, People’s Republic of China Objective: The objective of the present investigation was to study the clinical significances of the abnormal expressions of Piwil1 and Piwil2 protein in colonic adenoma and adenocarcinoma.Methods: This study had applied immunohistochemical method to detect 45 cases of tissues adjacent to carcinoma (distance to cancerous tissue was above 5 cm, 41 cases of colonic adenoma and 92 cases of colon cancer tissues, and their Piwil1 and Piwil2 protein expression levels.Analysis: The correlation of both expression and its relationship with clinicopathological features of colon cancer was analyzed.Results: Positive expression rates of Piwil1 in tissues adjacent to carcinoma, colonic adenoma, and colon cancer were 11.1% (5/45, 53.7% (22/41, and 80.4% (74/92, respectively; the expression rates increased, and the comparisons between each two groups were statistically significant (P<0.05. In each group, the positive expression rates of Piwil2 were 24.4% (11/45 cases, 75.6% (31/41 cases, and 92.4% (85/92 cases; expression rates increased, and the comparisons between each two groups were statistically significant (P<0.05. Piwil1 expression and the correlation of the degree of differentiation, TNM stage, and lymph node metastasis were statistically significant (P<0.05. Piwil2 expression and the correlation of the degree of differentiation, tumor node metastasis (TNM stage, and lymph node metastasis had no statistical significance (P>0.05. In colon cancer tissue, Piwil1 and Piwil2 expressions were positively correlated (r=0.262, P<0.05.Conclusion: The results showed that the abnormal expression of Piwil1 and Piwil2 might play an important role in

Prevention measures for avoiding unexpected drifting of marine component in recovery equipment of significant metals from sea water. Positioning and monitoring system for marine component and improvement of its positioning accuracy

Energy Technology Data Exchange (ETDEWEB)

Tamada, Masao; Kasai, Noboru; Seko, Noriaki; Hasegawa, Shin; Takeda, Hayato; Katakai, Akio; Sugo, Takanobu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Kawabata, Yukiya [Ebara Reseach Co., Ltd., Fujisawa, Kanagawa (Japan); Onuma, Kenji [Mitsubishi Materials Corp., Tokyo (Japan)

2001-11-01

Positioning and monitoring system for marine component in recovery equipment of significant metals from seawater with adsorbent was designed and assembled to avoid unexpected drifting accident. This system which was set on float part of the marine component obtains the positioning data from GPS satellites and sends them to Takasaki and Mutsu establishments through satellite communication. In both establishments, the position data were shown in computer displays. As characteristic test for 20 days in the real sea, 262 data were obtained every 2 hours. The twice of the distance root mean square (2DRMS) was 223.7 m. To improve this performance, three new functions were added to the present firmware. There are to raise positioning resolutions in longitude and latitude from 0.001 to 0.00001 degree, to remove the reflection of GPS signal from sea surface, and to average remaining three positioning data after maximum and minimum data were omitted from continuous five positioning data. The improved system shows the 2DRMS positioning of 15.5 m. This performance is enough to prevent marine component from its drifting accident. (author)

a Statistical Analysis on the System Performance of a Bluetooth Low Energy Indoor Positioning System in a 3d Environment

Science.gov (United States)

Haagmans, G. G.; Verhagen, S.; Voûte, R. L.; Verbree, E.

2017-09-01

Since GPS tends to fail for indoor positioning purposes, alternative methods like indoor positioning systems (IPS) based on Bluetooth low energy (BLE) are developing rapidly. Generally, IPS are deployed in environments covered with obstacles such as furniture, walls, people and electronics influencing the signal propagation. The major factor influencing the system performance and to acquire optimal positioning results is the geometry of the beacons. The geometry of the beacons is limited to the available infrastructure that can be deployed (number of beacons, basestations and tags), which leads to the following challenge: Given a limited number of beacons, where should they be placed in a specified indoor environment, such that the geometry contributes to optimal positioning results? This paper aims to propose a statistical model that is able to select the optimal configuration that satisfies the user requirements in terms of precision. The model requires the definition of a chosen 3D space (in our case 7 × 10 × 6 meter), number of beacons, possible user tag locations and a performance threshold (e.g. required precision). For any given set of beacon and receiver locations, the precision, internal- and external reliability can be determined on forehand. As validation, the modeled precision has been compared with observed precision results. The measurements have been performed with an IPS of BlooLoc at a chosen set of user tag locations for a given geometric configuration. Eventually, the model is able to select the optimal geometric configuration out of millions of possible configurations based on a performance threshold (e.g. required precision).

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

Science.gov (United States)

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

2015-03-01

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

Reporting of Positive Results in Randomized Controlled Trials of Mindfulness-Based Mental Health Interventions.

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Stephanie Coronado-Montoya

Full Text Available A large proportion of mindfulness-based therapy trials report statistically significant results, even in the context of very low statistical power. The objective of the present study was to characterize the reporting of "positive" results in randomized controlled trials of mindfulness-based therapy. We also assessed mindfulness-based therapy trial registrations for indications of possible reporting bias and reviewed recent systematic reviews and meta-analyses to determine whether reporting biases were identified.CINAHL, Cochrane CENTRAL, EMBASE, ISI, MEDLINE, PsycInfo, and SCOPUS databases were searched for randomized controlled trials of mindfulness-based therapy. The number of positive trials was described and compared to the number that might be expected if mindfulness-based therapy were similarly effective compared to individual therapy for depression. Trial registries were searched for mindfulness-based therapy registrations. CINAHL, Cochrane CENTRAL, EMBASE, ISI, MEDLINE, PsycInfo, and SCOPUS were also searched for mindfulness-based therapy systematic reviews and meta-analyses.108 (87% of 124 published trials reported ≥1 positive outcome in the abstract, and 109 (88% concluded that mindfulness-based therapy was effective, 1.6 times greater than the expected number of positive trials based on effect size d = 0.55 (expected number positive trials = 65.7. Of 21 trial registrations, 13 (62% remained unpublished 30 months post-trial completion. No trial registrations adequately specified a single primary outcome measure with time of assessment. None of 36 systematic reviews and meta-analyses concluded that effect estimates were overestimated due to reporting biases.The proportion of mindfulness-based therapy trials with statistically significant results may overstate what would occur in practice.

Performance studies of GooFit on GPUs vs RooFit on CPUs while estimating the statistical significance of a new physical signal

Science.gov (United States)

Di Florio, Adriano

2017-10-01

In order to test the computing capabilities of GPUs with respect to traditional CPU cores a high-statistics toy Monte Carlo technique has been implemented both in ROOT/RooFit and GooFit frameworks with the purpose to estimate the statistical significance of the structure observed by CMS close to the kinematical boundary of the J/ψϕ invariant mass in the three-body decay B + → J/ψϕK +. GooFit is a data analysis open tool under development that interfaces ROOT/RooFit to CUDA platform on nVidia GPU. The optimized GooFit application running on GPUs hosted by servers in the Bari Tier2 provides striking speed-up performances with respect to the RooFit application parallelised on multiple CPUs by means of PROOF-Lite tool. The considerable resulting speed-up, evident when comparing concurrent GooFit processes allowed by CUDA Multi Process Service and a RooFit/PROOF-Lite process with multiple CPU workers, is presented and discussed in detail. By means of GooFit it has also been possible to explore the behaviour of a likelihood ratio test statistic in different situations in which the Wilks Theorem may or may not apply because its regularity conditions are not satisfied.

Rigorous Statistical Bounds in Uncertainty Quantification for One-Layer Turbulent Geophysical Flows

Science.gov (United States)

Qi, Di; Majda, Andrew J.

2018-04-01

Statistical bounds controlling the total fluctuations in mean and variance about a basic steady-state solution are developed for the truncated barotropic flow over topography. Statistical ensemble prediction is an important topic in weather and climate research. Here, the evolution of an ensemble of trajectories is considered using statistical instability analysis and is compared and contrasted with the classical deterministic instability for the growth of perturbations in one pointwise trajectory. The maximum growth of the total statistics in fluctuations is derived relying on the statistical conservation principle of the pseudo-energy. The saturation bound of the statistical mean fluctuation and variance in the unstable regimes with non-positive-definite pseudo-energy is achieved by linking with a class of stable reference states and minimizing the stable statistical energy. Two cases with dependence on initial statistical uncertainty and on external forcing and dissipation are compared and unified under a consistent statistical stability framework. The flow structures and statistical stability bounds are illustrated and verified by numerical simulations among a wide range of dynamical regimes, where subtle transient statistical instability exists in general with positive short-time exponential growth in the covariance even when the pseudo-energy is positive-definite. Among the various scenarios in this paper, there exist strong forward and backward energy exchanges between different scales which are estimated by the rigorous statistical bounds.

Inequalities in child mortality in Mozambique: differentials by parental socio-economic position

DEFF Research Database (Denmark)

Macassa, Gloria; Ghilagaber, Gebrenegus; Bernhardt, Eva

2003-01-01

This study investigates the relation between socio-economic parental position (education and occupation) and child death in Mozambique using data from the Mozambican Demographic and Health Survey carried out between March and July 1997. The analysis included 9142 children born within 10 years...... before the survey. In spite of the Western system of classification used in the study, the results partly showed a parental socio-economic gradient of infant and child mortality in Mozambique. Father's education seemed to reflect the family's social standing in the Mozambique context, showing a strong...... statistical association with postneonatal and child mortality. However, maternal education as a measure of socio-economic position was not statistically significantly associated with child mortality. This finding may partly be explained by the extreme hardships experienced by the country (civil war...

Negative values of quasidistributions and quantum wave and number statistics

Science.gov (United States)

Peřina, J.; Křepelka, J.

2018-04-01

We consider nonclassical wave and number quantum statistics, and perform a decomposition of quasidistributions for nonlinear optical down-conversion processes using Bessel functions. We show that negative values of the quasidistribution do not directly represent probabilities; however, they directly influence measurable number statistics. Negative terms in the decomposition related to the nonclassical behavior with negative amplitudes of probability can be interpreted as positive amplitudes of probability in the negative orthogonal Bessel basis, whereas positive amplitudes of probability in the positive basis describe classical cases. However, probabilities are positive in all cases, including negative values of quasidistributions. Negative and positive contributions of decompositions to quasidistributions are estimated. The approach can be adapted to quantum coherence functions.

A tomographic study of the condyle position in temporomandibular disorders

International Nuclear Information System (INIS)

Choi, Sung Youn; Ryu, Young Kyu

1988-01-01

The aim of this study was to determine whether T.M.J. tomographic examination yielded significant difference in condyle positions among asymptomatic, myalgia, derangement, and arthrosis group of T.M.J. disorders. The author obtained sagittal linear tomograms of right and left T.M.Js. of 36 asymptomatic, 22 myalgia, 54 derangement, and 31 arthrosis patients taken at serial lateral, central, and medial sections in the intercuspal position after submentovertex radiographs analyzed. With the dual linear measurements of the posterior and anterior interarticular space, condyle positions were mathematically expressed as proportion. All data from these analysis was recorded and processed statistically. The results were obtained as follows: 1. In asymptomatic group, radiographically concentric condyle position was found in 50.0% to 65.4% of subjects, with a substance range of variability. No significant differences existed between men and women and also between right and left T.M.Js. for condyle position. 2. In women, significant difference for mean condyle position of left lateral section of each diagnostic category existed between derangement and myalgia groups (P< .05). Also that of left central section existed between derangement and myalgia group, and that of left medial section existed between derangement and myalgia groups (P< . 05). 3. In main-symptom side, condyle position in myalgia group was more concentric, and condyle position in derangement and group was more posterior. This showed significant differences between derangement and myalgia groups in lateral, central, and medial sections of main symptom side, and only between derangement and myalgia groups in central section of contra-lateral sides (P< .05). Condyle position in arthrosis group was broadly distributed among all positions. 4. In contra-lateral side, significant difference for mean condyle position of central section of each symptomatic group existed between derangement and myalgia group (P< .05

A tomographic study of the condyle position in temporomandibular disorders

Energy Technology Data Exchange (ETDEWEB)

Choi, Sung Youn; Ryu, Young Kyu [Dept. of Oral Radiology, College of Dentistry, Yonsei University, Seoul (Korea, Republic of)

1988-11-15

The aim of this study was to determine whether T.M.J. tomographic examination yielded significant difference in condyle positions among asymptomatic, myalgia, derangement, and arthrosis group of T.M.J. disorders. The author obtained sagittal linear tomograms of right and left T.M.Js. of 36 asymptomatic, 22 myalgia, 54 derangement, and 31 arthrosis patients taken at serial lateral, central, and medial sections in the intercuspal position after submentovertex radiographs analyzed. With the dual linear measurements of the posterior and anterior interarticular space, condyle positions were mathematically expressed as proportion. All data from these analysis was recorded and processed statistically. The results were obtained as follows: 1. In asymptomatic group, radiographically concentric condyle position was found in 50.0% to 65.4% of subjects, with a substance range of variability. No significant differences existed between men and women and also between right and left T.M.Js. for condyle position. 2. In women, significant difference for mean condyle position of left lateral section of each diagnostic category existed between derangement and myalgia groups (P< .05). Also that of left central section existed between derangement and myalgia group, and that of left medial section existed between derangement and myalgia groups (P< . 05). 3. In main-symptom side, condyle position in myalgia group was more concentric, and condyle position in derangement and group was more posterior. This showed significant differences between derangement and myalgia groups in lateral, central, and medial sections of main symptom side, and only between derangement and myalgia groups in central section of contra-lateral sides (P< .05). Condyle position in arthrosis group was broadly distributed among all positions. 4. In contra-lateral side, significant difference for mean condyle position of central section of each symptomatic group existed between derangement and myalgia group (P< .05

Robust statistical methods for significance evaluation and applications in cancer driver detection and biomarker discovery

DEFF Research Database (Denmark)

Madsen, Tobias

2017-01-01

In the present thesis I develop, implement and apply statistical methods for detecting genomic elements implicated in cancer development and progression. This is done in two separate bodies of work. The first uses the somatic mutation burden to distinguish cancer driver mutations from passenger m...

Use of iPhone technology in improving acetabular component position in total hip arthroplasty

Directory of Open Access Journals (Sweden)

Xiau Wei Tay, MBBS

2017-09-01

Full Text Available Improper acetabular cup positioning is associated with high risk of complications after total hip arthroplasty. The aim of our study is to objectively compare 3 methods, namely (1 free hand, (2 alignment jig (Sputnik, and (3 iPhone application to identify an easy, reproducible, and accurate method in improving acetabular cup placement. We designed a simple setup and carried out a simple experiment (see Method section. Using statistical analysis, the difference in inclination angles using iPhone application compared with the freehand method was found to be statistically significant (F[2,51] = 4.17, P = .02 in the “untrained group”. There is no statistical significance detected for the other groups. This suggests a potential role for iPhone applications in junior surgeons in overcoming the steep learning curve.

Significance of Waterway Navigation Positioning Systems On Ship's Manoeuvring Safety

Science.gov (United States)

Galor, W.

The main goal of navigation is to lead the ship to the point of destination safety and efficiently. Various factors may affect ship realisating this process. The ship movement on waterway are mainly limited by water area dimensions (surface and depth). These limitations cause the requirement to realise the proper of ship movement trajectory. In case when this re requirement cant't fulfil then marine accident may happend. This fact is unwanted event caused losses of human health and life, damage or loss of cargo and ship, pollution of natural environment, damage of port structures or blocking the port of its ports and lost of salvage operation. These losses in same cases can be catas- trophical especially while e.i. crude oil spilling could be place. To realise of safety navigation process is needed to embrace the ship's movement trajectory by waterways area. The ship's trajectory is described by manoeuvring lane as a surface of water area which is require to realise of safety ship movement. Many conditions affect to ship manoeuvring line. The main are following: positioning accuracy, ship's manoeuvring features and phenomena's of shore and ship's bulk common affecting. The accuracy of positioning system is most important. This system depends on coast navigation mark- ing which can range many kinds of technical realisation. Mainly used systems based on lights (line), radionavigation (local system or GPS, DGPS), or radars. If accuracy of positiong is higer, then safety of navigation is growing. This article presents these problems exemplifying with approaching channel to ports situated on West Pomera- nian water region.

Knot positioning during McDonald cervical cerclage, does it make a difference? A cohort study.

Science.gov (United States)

Atia, Hytham; Ellaithy, Mohamed; Altraigey, Ahmed; Ibrahim, Heba

2018-05-15

To study the effect of McDonald cerclage knot position on the different maternal and neonatal outcomes. This historical cohort study included women with singleton pregnancy who had a prophylactic McDonald cervical cerclage between 1 May 2010 and 31 September 2017. Maternal and neonatal outcome parameters were compared between the anterior and posterior knot cerclage procedures. The primary outcome measure was the rate of term birth. 550 Women had a prophylactic McDonald cervical cerclage, 306 with anterior knot (Group A) and 244 with posterior knot (Group B). There were no statistically significant differences regarding gestational age (GA) at delivery (36.3 ± 4.2 versus 35.8 ± 5.3 for groups A and B respectively), term birth rate, post-cerclage cervical length, symptomatic vaginitis, urinary tract infection, difficult cerclage removal and cervical lacerations. Similarly, there were no statistically significant differences as regards the studied neonatal outcomes including take home babies, neonatal intensive care admission, respiratory distress syndrome and neonatal sepsis. Survival analysis on GA at delivery demonstrated no statistically significant difference as regards the proportion of term deliveries in the anterior and posterior knot cerclage groups (log-rank test p-value = .478). Knot positioning during McDonald cervical cerclage, anteriorly or posteriorly, didn't significantly impact the studied maternal and neonatal outcomes.

Mathematics Anxiety and Statistics Anxiety. Shared but Also Unshared Components and Antagonistic Contributions to Performance in Statistics

Science.gov (United States)

Paechter, Manuela; Macher, Daniel; Martskvishvili, Khatuna; Wimmer, Sigrid; Papousek, Ilona

2017-01-01

In many social science majors, e.g., psychology, students report high levels of statistics anxiety. However, these majors are often chosen by students who are less prone to mathematics and who might have experienced difficulties and unpleasant feelings in their mathematics courses at school. The present study investigates whether statistics anxiety is a genuine form of anxiety that impairs students' achievements or whether learners mainly transfer previous experiences in mathematics and their anxiety in mathematics to statistics. The relationship between mathematics anxiety and statistics anxiety, their relationship to learning behaviors and to performance in a statistics examination were investigated in a sample of 225 undergraduate psychology students (164 women, 61 men). Data were recorded at three points in time: At the beginning of term students' mathematics anxiety, general proneness to anxiety, school grades, and demographic data were assessed; 2 weeks before the end of term, they completed questionnaires on statistics anxiety and their learning behaviors. At the end of term, examination scores were recorded. Mathematics anxiety and statistics anxiety correlated highly but the comparison of different structural equation models showed that they had genuine and even antagonistic contributions to learning behaviors and performance in the examination. Surprisingly, mathematics anxiety was positively related to performance. It might be that students realized over the course of their first term that knowledge and skills in higher secondary education mathematics are not sufficient to be successful in statistics. Part of mathematics anxiety may then have strengthened positive extrinsic effort motivation by the intention to avoid failure and may have led to higher effort for the exam preparation. However, via statistics anxiety mathematics anxiety also had a negative contribution to performance. Statistics anxiety led to higher procrastination in the structural

Mathematics Anxiety and Statistics Anxiety. Shared but Also Unshared Components and Antagonistic Contributions to Performance in Statistics.

Science.gov (United States)

Paechter, Manuela; Macher, Daniel; Martskvishvili, Khatuna; Wimmer, Sigrid; Papousek, Ilona

2017-01-01

In many social science majors, e.g., psychology, students report high levels of statistics anxiety. However, these majors are often chosen by students who are less prone to mathematics and who might have experienced difficulties and unpleasant feelings in their mathematics courses at school. The present study investigates whether statistics anxiety is a genuine form of anxiety that impairs students' achievements or whether learners mainly transfer previous experiences in mathematics and their anxiety in mathematics to statistics. The relationship between mathematics anxiety and statistics anxiety, their relationship to learning behaviors and to performance in a statistics examination were investigated in a sample of 225 undergraduate psychology students (164 women, 61 men). Data were recorded at three points in time: At the beginning of term students' mathematics anxiety, general proneness to anxiety, school grades, and demographic data were assessed; 2 weeks before the end of term, they completed questionnaires on statistics anxiety and their learning behaviors. At the end of term, examination scores were recorded. Mathematics anxiety and statistics anxiety correlated highly but the comparison of different structural equation models showed that they had genuine and even antagonistic contributions to learning behaviors and performance in the examination. Surprisingly, mathematics anxiety was positively related to performance. It might be that students realized over the course of their first term that knowledge and skills in higher secondary education mathematics are not sufficient to be successful in statistics. Part of mathematics anxiety may then have strengthened positive extrinsic effort motivation by the intention to avoid failure and may have led to higher effort for the exam preparation. However, via statistics anxiety mathematics anxiety also had a negative contribution to performance. Statistics anxiety led to higher procrastination in the structural

Mathematics Anxiety and Statistics Anxiety. Shared but Also Unshared Components and Antagonistic Contributions to Performance in Statistics

Directory of Open Access Journals (Sweden)

Manuela Paechter

2017-07-01

Full Text Available In many social science majors, e.g., psychology, students report high levels of statistics anxiety. However, these majors are often chosen by students who are less prone to mathematics and who might have experienced difficulties and unpleasant feelings in their mathematics courses at school. The present study investigates whether statistics anxiety is a genuine form of anxiety that impairs students' achievements or whether learners mainly transfer previous experiences in mathematics and their anxiety in mathematics to statistics. The relationship between mathematics anxiety and statistics anxiety, their relationship to learning behaviors and to performance in a statistics examination were investigated in a sample of 225 undergraduate psychology students (164 women, 61 men. Data were recorded at three points in time: At the beginning of term students' mathematics anxiety, general proneness to anxiety, school grades, and demographic data were assessed; 2 weeks before the end of term, they completed questionnaires on statistics anxiety and their learning behaviors. At the end of term, examination scores were recorded. Mathematics anxiety and statistics anxiety correlated highly but the comparison of different structural equation models showed that they had genuine and even antagonistic contributions to learning behaviors and performance in the examination. Surprisingly, mathematics anxiety was positively related to performance. It might be that students realized over the course of their first term that knowledge and skills in higher secondary education mathematics are not sufficient to be successful in statistics. Part of mathematics anxiety may then have strengthened positive extrinsic effort motivation by the intention to avoid failure and may have led to higher effort for the exam preparation. However, via statistics anxiety mathematics anxiety also had a negative contribution to performance. Statistics anxiety led to higher procrastination in

Prognostic Significance of the Number of Positive Lymph Nodes in Women With T1-2N1 Breast Cancer Treated With Mastectomy: Should Patients With 1, 2, and 3 Positive Lymph Nodes Be Grouped Together?

Energy Technology Data Exchange (ETDEWEB)

Dai Kubicky, Charlotte, E-mail: charlottedai@gmail.com [Department of Radiation Medicine and Knight Cancer Institute, Oregon Health and Science University, Portland, Oregon (United States); Mongoue-Tchokote, Solange [Biostatistics Shared Resource, Knight Cancer Institute, Oregon Health and Science University, Portland, Oregon (United States)

2013-04-01

Purpose: To determine whether patients with 1, 2, or 3 positive lymph nodes (LNs) have similar survival outcomes. Methods and Materials: We analyzed the Surveillance, Epidemiology, and End Results registry of breast cancer patients diagnosed between 1990 and 2003. We identified 10,415 women with T1-2N1M0 breast cancer who were treated with mastectomy with no adjuvant radiation, with at least 10 LNs examined and 6 months of follow-up. The Kaplan-Meier method and log–rank test were used for survival analysis. Multivariate analysis was performed using the Cox proportional hazard model. Results: Median follow-up was 92 months. Ten-year overall survival (OS) and cause-specific survival (CSS) were progressively worse with increasing number of positive LNs. Survival rates were 70%, 64%, and 60% (OS), and 82%, 76%, and 72% (CSS) for 1, 2, and 3 positive LNs, respectively. Pairwise log–rank test P values were <.001 (1 vs 2 positive LNs), <.001 (1 vs 3 positive LNs), and .002 (2 vs 3 positive LNs). Multivariate analysis showed that number of positive LNs was a significant predictor of OS and CSS. Hazard ratios increased with the number of positive LNs. In addition, age, primary tumor size, grade, estrogen receptor and progesterone receptor status, race, and year of diagnosis were significant prognostic factors. Conclusions: Our study suggests that patients with 1, 2, and 3 positive LNs have distinct survival outcomes, with increasing number of positive LNs associated with worse OS and CSS. The conventional grouping of 1-3 positive LNs needs to be reconsidered.

Significance evaluation in factor graphs

DEFF Research Database (Denmark)

Madsen, Tobias; Hobolth, Asger; Jensen, Jens Ledet

2017-01-01

in genomics and the multiple-testing issues accompanying them, accurate significance evaluation is of great importance. We here address the problem of evaluating statistical significance of observations from factor graph models. Results Two novel numerical approximations for evaluation of statistical...... significance are presented. First a method using importance sampling. Second a saddlepoint approximation based method. We develop algorithms to efficiently compute the approximations and compare them to naive sampling and the normal approximation. The individual merits of the methods are analysed both from....... Conclusions The applicability of saddlepoint approximation and importance sampling is demonstrated on known models in the factor graph framework. Using the two methods we can substantially improve computational cost without compromising accuracy. This contribution allows analyses of large datasets...

Long-term neuromuscular training and ankle joint position sense.

Science.gov (United States)

Kynsburg, A; Pánics, G; Halasi, T

2010-06-01

Preventive effect of proprioceptive training is proven by decreasing injury incidence, but its proprioceptive mechanism is not. Major hypothesis: the training has a positive long-term effect on ankle joint position sense in athletes of a high-risk sport (handball). Ten elite-level female handball-players represented the intervention group (training-group), 10 healthy athletes of other sports formed the control-group. Proprioceptive training was incorporated into the regular training regimen of the training-group. Ankle joint position sense function was measured with the "slope-box" test, first described by Robbins et al. Testing was performed one day before the intervention and 20 months later. Mean absolute estimate errors were processed for statistical analysis. Proprioceptive sensory function improved regarding all four directions with a high significance (pneuromuscular training has improved ankle joint position sense function in the investigated athletes. This joint position sense improvement can be one of the explanations for injury rate reduction effect of neuromuscular training.

The Status of Positive Psychology Strengths within the Romanian School in the Digital Society

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Georgeta Pânişoară

2017-01-01

Full Text Available The aim of this study is to identify the possible correlations between the strengths that are taught in school and those which are necessary for reaching personal success. In order to test the extent to which these strengths correlate, we applied a psychological-assessment tool composed of 24 strengths with a Likert-type response scale. The subjects selected for this research were 100 teachers from Romania, both male and female. The results were processed in SPSS Statistics, where we also calculated Pearson's correlation coefficient. After analyzing the descriptive statistics and the correlation coefficient we noticed that the "Vitality" strength showed a statistically significant negative correlation between the two groups, therefore it is not taught in school but it is considered important for achieving personal success. The "Citizenship" strength showed a statistically significant positive correlation, being concurrently promoted in school and important in achieving success.The neuro-linguistic reprogramming of a young individual will need a considerable effort, first of all as regards being aware of the values which render his well-being, and secondly as regards his orientation towards these values, which as it seems he was not at all oriented to. The new student profile of today’s society, also known as the digital native, needs to assimilate a full set of positive psychology values in order to create a complete model of success for nowadays’ world.

LOD significance thresholds for QTL analysis in experimental populations of diploid species

Science.gov (United States)

Van Ooijen JW

1999-11-01

Linkage analysis with molecular genetic markers is a very powerful tool in the biological research of quantitative traits. The lack of an easy way to know what areas of the genome can be designated as statistically significant for containing a gene affecting the quantitative trait of interest hampers the important prediction of the rate of false positives. In this paper four tables, obtained by large-scale simulations, are presented that can be used with a simple formula to get the false-positives rate for analyses of the standard types of experimental populations with diploid species with any size of genome. A new definition of the term 'suggestive linkage' is proposed that allows a more objective comparison of results across species.

Significance and management of positive surgical margins at the time of radical prostatectomy.

Science.gov (United States)

Silberstein, Jonathan L; Eastham, James A

2014-10-01

Positive surgical margins (PSM) at the time of radical prostatectomy (RP) result in an increased risk of biochemical recurrence (BCR) and secondary treatment. We review current literature with a focus on stratifying the characteristics of the PSM that may define its significance, the impact of modern imaging and surgical approaches in avoidance of PSM, and management strategies when PSM do occur. We performed a review of the available literature to identify factors associated with PSM and their management. PSM have been repeatedly demonstrated to be associated with an increased risk of BCR following RP. The specific characteristics (size, number, location, Gleason score at the margin) of the PSM may influence the risk of recurrence. Novel imaging and surgical approaches are being investigated and may allow for reductions of PSM in the future. The use of adjuvant treatment for a PSM remains controversial and should be decided on an individual basis after a discussion about the risks and benefits. The goal of RP is complete resection of the tumor. PSM are associated with increased risk of BCR and secondary treatments. Of the risk factors associated with BCR after RP, a PSM is directly influenced by surgical technique.

Significance and management of positive surgical margins at the time of radical prostatectomy

Directory of Open Access Journals (Sweden)

Jonathan L. Silberstein

2014-01-01

Full Text Available Positive surgical margins (PSM at the time of radical prostatectomy (RP result in an increased risk of biochemical recurrence (BCR and secondary treatment. We review current literature with a focus on stratifying the characteristics of the PSM that may define its significance, the impact of modern imaging and surgical approaches in avoidance of PSM, and management strategies when PSM do occur. We performed a review of the available literature to identify factors associated with PSM and their management. PSM have been repeatedly demonstrated to be associated with an increased risk of BCR following RP. The specific characteristics (size, number, location, Gleason score at the margin of the PSM may influence the risk of recurrence. Novel imaging and surgical approaches are being investigated and may allow for reductions of PSM in the future. The use of adjuvant treatment for a PSM remains controversial and should be decided on an individual basis after a discussion about the risks and benefits. The goal of RP is complete resection of the tumor. PSM are associated with increased risk of BCR and secondary treatments. Of the risk factors associated with BCR after RP, a PSM is directly influenced by surgical technique.

Probabilistic and Statistical Aspects of Quantum Theory

CERN Document Server

Holevo, Alexander S

2011-01-01

This book is devoted to aspects of the foundations of quantum mechanics in which probabilistic and statistical concepts play an essential role. The main part of the book concerns the quantitative statistical theory of quantum measurement, based on the notion of positive operator-valued measures. During the past years there has been substantial progress in this direction, stimulated to a great extent by new applications such as Quantum Optics, Quantum Communication and high-precision experiments. The questions of statistical interpretation, quantum symmetries, theory of canonical commutation re

Statistical measures of galaxy clustering

International Nuclear Information System (INIS)

Porter, D.H.

1988-01-01

Consideration is given to the large-scale distribution of galaxies and ways in which this distribution may be statistically measured. Galaxy clustering is hierarchical in nature, so that the positions of clusters of galaxies are themselves spatially clustered. A simple identification of groups of galaxies would be an inadequate description of the true richness of galaxy clustering. Current observations of the large-scale structure of the universe and modern theories of cosmology may be studied with a statistical description of the spatial and velocity distributions of galaxies. 8 refs

Statistical analysis of acoustic characteristics of Tibetan Lhasa dialect speech emotion

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Guo Dandan

2016-01-01

Full Text Available The paper makes a quantitative analysis and comparison on the continuous speech emotion of Lhasa Tibetan in the four basic emotional patterns (happy, surprise, sad, neutral pitch, energy and time length by experimental phonetics and the linear statistical research methods, found that there is a positive correlation between the Lhasa Tibetan emotional speech and pitch, energy and duration, etc. And the pitch, energy and duration of negative emotion acoustic parameters are bigger than positive emotion, on this basis, drawing the Lhasa Tibetan speech emotion acoustic feature patterns. Compared with the Chinese language and the Tibetan, even though both have the tone prosodic features, they also have significant differences in the acoustic characteristics of the speech emotion.

Assessing attitudes towards statistics among medical students: psychometric properties of the Serbian version of the Survey of Attitudes Towards Statistics (SATS.

Directory of Open Access Journals (Sweden)

Dejana Stanisavljevic

Full Text Available BACKGROUND: Medical statistics has become important and relevant for future doctors, enabling them to practice evidence based medicine. Recent studies report that students' attitudes towards statistics play an important role in their statistics achievements. The aim of the study was to test the psychometric properties of the Serbian version of the Survey of Attitudes Towards Statistics (SATS in order to acquire a valid instrument to measure attitudes inside the Serbian educational context. METHODS: The validation study was performed on a cohort of 417 medical students who were enrolled in an obligatory introductory statistics course. The SATS adaptation was based on an internationally accepted methodology for translation and cultural adaptation. Psychometric properties of the Serbian version of the SATS were analyzed through the examination of factorial structure and internal consistency. RESULTS: Most medical students held positive attitudes towards statistics. The average total SATS score was above neutral (4.3±0.8, and varied from 1.9 to 6.2. Confirmatory factor analysis validated the six-factor structure of the questionnaire (Affect, Cognitive Competence, Value, Difficulty, Interest and Effort. Values for fit indices TLI (0.940 and CFI (0.961 were above the cut-off of ≥0.90. The RMSEA value of 0.064 (0.051-0.078 was below the suggested value of ≤0.08. Cronbach's alpha of the entire scale was 0.90, indicating scale reliability. In a multivariate regression model, self-rating of ability in mathematics and current grade point average were significantly associated with the total SATS score after adjusting for age and gender. CONCLUSION: Present study provided the evidence for the appropriate metric properties of the Serbian version of SATS. Confirmatory factor analysis validated the six-factor structure of the scale. The SATS might be reliable and a valid instrument for identifying medical students' attitudes towards statistics in the

Assessing attitudes towards statistics among medical students: psychometric properties of the Serbian version of the Survey of Attitudes Towards Statistics (SATS).

Science.gov (United States)

Stanisavljevic, Dejana; Trajkovic, Goran; Marinkovic, Jelena; Bukumiric, Zoran; Cirkovic, Andja; Milic, Natasa

2014-01-01

Medical statistics has become important and relevant for future doctors, enabling them to practice evidence based medicine. Recent studies report that students' attitudes towards statistics play an important role in their statistics achievements. The aim of the study was to test the psychometric properties of the Serbian version of the Survey of Attitudes Towards Statistics (SATS) in order to acquire a valid instrument to measure attitudes inside the Serbian educational context. The validation study was performed on a cohort of 417 medical students who were enrolled in an obligatory introductory statistics course. The SATS adaptation was based on an internationally accepted methodology for translation and cultural adaptation. Psychometric properties of the Serbian version of the SATS were analyzed through the examination of factorial structure and internal consistency. Most medical students held positive attitudes towards statistics. The average total SATS score was above neutral (4.3±0.8), and varied from 1.9 to 6.2. Confirmatory factor analysis validated the six-factor structure of the questionnaire (Affect, Cognitive Competence, Value, Difficulty, Interest and Effort). Values for fit indices TLI (0.940) and CFI (0.961) were above the cut-off of ≥0.90. The RMSEA value of 0.064 (0.051-0.078) was below the suggested value of ≤0.08. Cronbach's alpha of the entire scale was 0.90, indicating scale reliability. In a multivariate regression model, self-rating of ability in mathematics and current grade point average were significantly associated with the total SATS score after adjusting for age and gender. Present study provided the evidence for the appropriate metric properties of the Serbian version of SATS. Confirmatory factor analysis validated the six-factor structure of the scale. The SATS might be reliable and a valid instrument for identifying medical students' attitudes towards statistics in the Serbian educational context.

FDG uptake in vaginal tampons is caused by urinary contamination and related to tampon position

International Nuclear Information System (INIS)

Burger, Irene A.; Crook, David W.; Treyer, Valerie; Hany, Thomas F.; Schulthess, Gustav K. von; Scheiner, David A.

2011-01-01

The aim of the study was to determine the aetiology of FDG uptake in vaginal tampons (VT), a known artefact in premenopausal women evaluated by PET/CT. This Institutional Review Board approved study consisted of retrospective and prospective parts. The retrospective analysis included 685 women examined between January 2008 and December 2009 regarding VT presence. PET/CT images were analysed to determine the localization and the standardized uptake value (SUV) of VTs. We prospectively recruited 24 women (20-48 years old) referred for staging or follow-up in an oncology setting between February and April 2010, who were provided a commercial VT to be used during the entire examination after obtaining written informed consent. After image acquisition, VTs were individually analysed for creatinine concentration and blood traces. Statistical significance was tested with the Mann-Whitney U test. In the retrospective part, 38 of 685 women were found to have a VT of which 17 (45%) were FDG positive. A statistically significant correlation was found between FDG activity and VT position below the pubococcygeal line (PCL) (13 ± 11.2 mm). In the prospective study, 7 of 24 (29%) women had increased FDG activity in their VTs (SUV 18.8 ± 11 g/ml) but were not menstruating. FDG-positive VTs were significantly lower in position (14.6 ± 11.4 mm,below the PCL) than FDG-negative VTs (p = 0.039). The creatinine concentration was significantly increased in all seven positive VTs (931 ± 615 μmol/l). FDG uptake in VTs is caused by urine contamination, which is likely related to localization below the PCL resulting in contact with urine during voiding. (orig.)

Cluster-level statistical inference in fMRI datasets: The unexpected behavior of random fields in high dimensions.

Science.gov (United States)

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

Statistical lamb wave localization based on extreme value theory

Science.gov (United States)

Harley, Joel B.

2018-04-01

Guided wave localization methods based on delay-and-sum imaging, matched field processing, and other techniques have been designed and researched to create images that locate and describe structural damage. The maximum value of these images typically represent an estimated damage location. Yet, it is often unclear if this maximum value, or any other value in the image, is a statistically significant indicator of damage. Furthermore, there are currently few, if any, approaches to assess the statistical significance of guided wave localization images. As a result, we present statistical delay-and-sum and statistical matched field processing localization methods to create statistically significant images of damage. Our framework uses constant rate of false alarm statistics and extreme value theory to detect damage with little prior information. We demonstrate our methods with in situ guided wave data from an aluminum plate to detect two 0.75 cm diameter holes. Our results show an expected improvement in statistical significance as the number of sensors increase. With seventeen sensors, both methods successfully detect damage with statistical significance.

Statistical testing and power analysis for brain-wide association study.

Science.gov (United States)

Gong, Weikang; Wan, Lin; Lu, Wenlian; Ma, Liang; Cheng, Fan; Cheng, Wei; Grünewald, Stefan; Feng, Jianfeng

2018-04-05

The identification of connexel-wise associations, which involves examining functional connectivities between pairwise voxels across the whole brain, is both statistically and computationally challenging. Although such a connexel-wise methodology has recently been adopted by brain-wide association studies (BWAS) to identify connectivity changes in several mental disorders, such as schizophrenia, autism and depression, the multiple correction and power analysis methods designed specifically for connexel-wise analysis are still lacking. Therefore, we herein report the development of a rigorous statistical framework for connexel-wise significance testing based on the Gaussian random field theory. It includes controlling the family-wise error rate (FWER) of multiple hypothesis testings using topological inference methods, and calculating power and sample size for a connexel-wise study. Our theoretical framework can control the false-positive rate accurately, as validated empirically using two resting-state fMRI datasets. Compared with Bonferroni correction and false discovery rate (FDR), it can reduce false-positive rate and increase statistical power by appropriately utilizing the spatial information of fMRI data. Importantly, our method bypasses the need of non-parametric permutation to correct for multiple comparison, thus, it can efficiently tackle large datasets with high resolution fMRI images. The utility of our method is shown in a case-control study. Our approach can identify altered functional connectivities in a major depression disorder dataset, whereas existing methods fail. A software package is available at https://github.com/weikanggong/BWAS. Copyright © 2018 Elsevier B.V. All rights reserved.

Significance of specificity of Tinetti B-POMA test and fall risk factor in third age of life.

Science.gov (United States)

Avdić, Dijana; Pecar, Dzemal

2006-02-01

As for the third age, psychophysical abilities of humans gradually decrease, while the ability of adaptation to endogenous and exogenous burdens is going down. In 1987, "Harada" et al. (1) have found out that 9.5 million persons in USA have difficulties running daily activities, while 59% of them (which is 5.6 million) are older than 65 years in age. The study has encompassed 77 questioned persons of both sexes with their average age 71.73 +/- 5.63 (scope of 65-90 years in age), chosen by random sampling. Each patient has been questioned in his/her own home and familiar to great extent with the methodology and aims of the questionnaire. Percentage of questioned women was 64.94% (50 patients) while the percentage for men was 35.06% (27 patients). As for the value of risk factor score achieved conducting the questionnaire and B-POMA test, there are statistically significant differences between men and women, as well as between patients who fell and those who never did. As for the way of life (alone or in the community), there are no significant statistical differences. Average results gained through B-POMA test in this study are statistically significantly higher in men and patients who did not provide data about falling, while there was no statistically significant difference in the way of life. In relation to the percentage of maximum number of positive answers to particular questions, regarding gender, way of life and the data about falling, there were no statistically significant differences between the value of B-POMA test and the risk factor score (the questionnaire).

Significance of β-tubulin Expression in Breast Premalignant Lesions and Carcinomas

Institute of Scientific and Technical Information of China (English)

Yuxia Gao; Yun Niu; Xiumin Ding; Yong Yu

2008-01-01

OBJECTIVE To explore the expression of β-tubulin in premalignant lesions and carcinomas of the breast, and to observe the relationship of its expression with breast cancer pathological features.METHODS The expression of β-tubulin was detected immunohistochemically in 50 specimens of premalignant lesions of the breast (ADH and Peri-PM with ADH), 50 specimens of breast in situ ductal carcinomas (DCIS), and 50 specimens of invasive ductal carcinomas (IDC). Thirty specimens of normal breast tissues served as a control group.RESULTS Immunohistochemical analysis showed that: the differences among the 4 groups (normal breast tissues, breast premalignant lesions, DCIS and IDC, P ＜ 0.05) were significant,and there were also statistically significant differences between any 2 groups (P ＜ 0.05) except for the β-tubulin positive expression comparing DCIS versus IDC (P ＞ 0.05). In addition, β-tubulin was expressed at a higher level in Peri-PM with ADH compared to ADH (P ＜ 0.05). Following the degree of breast epithelial hyperplasia involved, and its development into carcinoma, the β-tubulin positive expression displayed an elevating tendency.We also found a significant positive relationship of β-tubulin expression with lymph node metastasis (P ＜ 0.05), but no significant correlation with histological grading and nuclear grade.CONCLUSION Centrosome defects may be an early event in the development of breast cancer and they can also promote tumor progression. Studies of aberrations of centrosomal proteins provide a new way to explore the mechanism of breast tumorigenesis.

Thermodynamics, Gibbs Method and Statistical Physics of Electron Gases Gibbs Method and Statistical Physics of Electron Gases

CERN Document Server

Askerov, Bahram M

2010-01-01

This book deals with theoretical thermodynamics and the statistical physics of electron and particle gases. While treating the laws of thermodynamics from both classical and quantum theoretical viewpoints, it posits that the basis of the statistical theory of macroscopic properties of a system is the microcanonical distribution of isolated systems, from which all canonical distributions stem. To calculate the free energy, the Gibbs method is applied to ideal and non-ideal gases, and also to a crystalline solid. Considerable attention is paid to the Fermi-Dirac and Bose-Einstein quantum statistics and its application to different quantum gases, and electron gas in both metals and semiconductors is considered in a nonequilibrium state. A separate chapter treats the statistical theory of thermodynamic properties of an electron gas in a quantizing magnetic field.

The choice of statistical methods for comparisons of dosimetric data in radiotherapy.

Science.gov (United States)

Chaikh, Abdulhamid; Giraud, Jean-Yves; Perrin, Emmanuel; Bresciani, Jean-Pierre; Balosso, Jacques

2014-09-18

Novel irradiation techniques are continuously introduced in radiotherapy to optimize the accuracy, the security and the clinical outcome of treatments. These changes could raise the question of discontinuity in dosimetric presentation and the subsequent need for practice adjustments in case of significant modifications. This study proposes a comprehensive approach to compare different techniques and tests whether their respective dose calculation algorithms give rise to statistically significant differences in the treatment doses for the patient. Statistical investigation principles are presented in the framework of a clinical example based on 62 fields of radiotherapy for lung cancer. The delivered doses in monitor units were calculated using three different dose calculation methods: the reference method accounts the dose without tissues density corrections using Pencil Beam Convolution (PBC) algorithm, whereas new methods calculate the dose with tissues density correction for 1D and 3D using Modified Batho (MB) method and Equivalent Tissue air ratio (ETAR) method, respectively. The normality of the data and the homogeneity of variance between groups were tested using Shapiro-Wilks and Levene test, respectively, then non-parametric statistical tests were performed. Specifically, the dose means estimated by the different calculation methods were compared using Friedman's test and Wilcoxon signed-rank test. In addition, the correlation between the doses calculated by the three methods was assessed using Spearman's rank and Kendall's rank tests. The Friedman's test showed a significant effect on the calculation method for the delivered dose of lung cancer patients (p Wilcoxon signed-rank test of paired comparisons indicated that the delivered dose was significantly reduced using density-corrected methods as compared to the reference method. Spearman's and Kendall's rank tests indicated a positive correlation between the doses calculated with the different methods

Significant changes in sexual behavior after a diagnosis of human papillomavirus-positive and human papillomavirus-negative oral cancer.

Science.gov (United States)

Taberna, Miren; Inglehart, Ronald C; Pickard, Robert K L; Fakhry, Carole; Agrawal, Amit; Katz, Mira L; Gillison, Maura L

2017-04-01

Sexual behavior and oral human papillomavirus (HPV) infection are risk factors for oral squamous cell carcinoma (OSCC). The effects of OSCC diagnosis and treatment on subsequent relationship stress and sexual behavior are unknown. Incident cases of HPV-positive or HPV-negative OSCC in patients who had a partnered relationship and partners of patients with oropharyngeal cancer were eligible for a study in which surveys were administered at diagnosis and at the 6-month follow-up time point to assess relationship distress, HPV transmission and concerns about health consequences, and sexual behavior. The frequency distributions of responses, stratified by tumor HPV status, were compared at baseline and follow-up. In total, 262 patients with OSCC and 81 partners were enrolled. Among the patients, 142 (54.2%) had HPV-positive OSCC, and 120 (45.8%) had HPV-negative OSCC. Relationship distress was infrequently reported, and 69% of patients felt that their relationship had strengthened since the cancer diagnosis. Both HPV-positive patients (25%) and their partners (14%) reported feelings of guilt or responsibility for the diagnosis of an HPV-caused cancer. Concern over sexual, but not nonsexual, HPV transmission to partners was reported by 50%. Significant declines in the frequency of vaginal and oral sexual behaviors were reported at follow-up, regardless of tumor HPV status. From baseline to 6 months, significant increases in abstinence from vaginal sex (from 10% to 34%; P oral sex (from 25% to 80%; P oral sex, regardless of tumor HPV status. Sexual behavior is an important quality-of-life outcome to assess within clinical trials. [See related editorial on pages 000-000, this issue.] Cancer 2017. © 2017 American Cancer Society. Cancer 2017;123:1156-1165. © 2016 American Cancer Society. © 2017 American Cancer Society.

Weighted statistical parameters for irregularly sampled time series

Science.gov (United States)

Rimoldini, Lorenzo

2014-01-01

Unevenly spaced time series are common in astronomy because of the day-night cycle, weather conditions, dependence on the source position in the sky, allocated telescope time and corrupt measurements, for example, or inherent to the scanning law of satellites like Hipparcos and the forthcoming Gaia. Irregular sampling often causes clumps of measurements and gaps with no data which can severely disrupt the values of estimators. This paper aims at improving the accuracy of common statistical parameters when linear interpolation (in time or phase) can be considered an acceptable approximation of a deterministic signal. A pragmatic solution is formulated in terms of a simple weighting scheme, adapting to the sampling density and noise level, applicable to large data volumes at minimal computational cost. Tests on time series from the Hipparcos periodic catalogue led to significant improvements in the overall accuracy and precision of the estimators with respect to the unweighted counterparts and those weighted by inverse-squared uncertainties. Automated classification procedures employing statistical parameters weighted by the suggested scheme confirmed the benefits of the improved input attributes. The classification of eclipsing binaries, Mira, RR Lyrae, Delta Cephei and Alpha2 Canum Venaticorum stars employing exclusively weighted descriptive statistics achieved an overall accuracy of 92 per cent, about 6 per cent higher than with unweighted estimators.

The determination of contribution of emotional intelligence and parenting styles components to predicts positive psychological components

Directory of Open Access Journals (Sweden)

hosein Ebrahimi moghadam

2015-05-01

Full Text Available Background: Since the essential of positive psychological components, as compliment of deficiency oriented approaches, has begun in recent days,we decided to take into account this new branch of psychology which scientifically considers studying forces of human, as well as because of the importance of this branch of psychology, we also tried to search the contribution of emotional intelligence and parenting styles components to predict positive psychological components. Materials and Methods:In this cross sectional study 200 psychological students of Azad university (Rudehen branch selected using cluster sampling method. Then they were estimated by Bradbery and Grivers emotional intelligence questionnaire , Bamrind parenting styles and Rajayi et al positive psychological components questionnaire. Research data was analyzed using descriptive statistics (mean and standard deviation, inferential statistics (multiple regression and Pierson correlation coefficient and SPSS software. Results:Among the components of emotional intelligence, the component of emotional self consciousness (β=0.464 had the greatest predictable , and reaction leadership showed no predictability in this research between parenting styles , authority parenting styles had positive significance relationship with positive psychological components. And no significant relationship was found between despot parenting styles and positive psychological components. Conclusion: Regarding the results of this research and importance of positive psychological components, it is suggested to treat the emotional intelligence from childhood and to learn it to parents and remind them the parenting way to decrease the satisfaction of individuals which leads to promotion of society mental health.

Positive and Negative Thinking in Tinnitus: Factor Structure of the Tinnitus Cognitions Questionnaire.

Science.gov (United States)

Handscomb, Lucy E; Hall, Deborah A; Shorter, Gillian W; Hoare, Derek J

Researchers and clinicians consider thinking to be important in the development and maintenance of tinnitus distress, and altering thoughts or thinking style is an object of many forms of psychological therapy for tinnitus. Those working with people with tinnitus require a reliable, psychometrically robust means of measuring both positive and negative thinking related to it. The Tinnitus Cognitions Questionnaire (TCQ) was designed as such a measure and its authors showed it to be reliable, with good psychometric properties. However, no research teams have yet carried out independent validation. This study aimed to use the TCQ to investigate thinking amongst members of the general population with both bothersome and nonbothersome tinnitus and also to verify its factor structure. Three hundred forty-two members of the public with tinnitus completed the TCQ online or on paper. They also rated their tinnitus on a scale as "not a problem," "a small problem," "a moderate problem," "a big problem," or a "very big problem." The authors tested the original factor structure of the TCQ using confirmatory factor analysis and then calculated the mean scores for each item, comparing mean total scores across "problem categories" for the full questionnaire and for the positive and negative subscales. The original two-factor structure of the TCQ was a good fit to the data when the correlation between positive and negative factors was fixed at zero (root mean square error of approximation = 0.064, 90% confidence interval = 0.058 to 0.070). Items pertaining to wishing the tinnitus would go away and despairing that it would ever get better had the highest mean scores. The mean total score for the "no problem" group (M = 31.17, SD = 16.03) was not significantly different from the mean total score for the "small problem" group (M = 34.00, SD = 12.44, p = 0.99). Differences between mean scores for all other groups were statistically significant. For the negative subscale, differences

Technical issues relating to the statistical parametric mapping of brain SPECT studies

International Nuclear Information System (INIS)

Hatton, R.L.; Cordato, N.; Hutton, B.F.; Lau, Y.H.; Evans, S.G.

2000-01-01

Full text: Statistical Parametric Mapping (SPM) is a software tool designed for the statistical analysis of functional neuro images, specifically Positron Emission Tomography and functional Magnetic Resonance Imaging, and more recently SPECT. This review examines some problems associated with the analysis of SPECT. A comparison of a patient group with normal studies revealed factors that could influence results, some that commonly occur, others that require further exploration. To optimise the differences between two groups of subjects, both spatial variability and differences in global activity must be minimised. The choice and effectiveness of co registration method and approach to normalisation of activity concentration can affect the optimisation. A small number of subject scans were identified as possessing truncated data resulting in edge effects that could adversely influence the analysis. Other problems included unusual areas of significance possibly related to reconstruction methods and the geometry associated with nonparallel collimators. Areas of extra cerebral significance are a point of concern - and may result from scatter effects, or mis registration. Difficulties in patient positioning, due to postural limitations, can lead to resolution differences. SPM has been used to assess areas of statistical significance arising from these technical factors, as opposed to areas of true clinical significance when comparing subject groups. This contributes to a better understanding of the effects of technical factors so that these may be eliminated, minimised, or incorporated in the study design. Copyright (2000) The Australian and New Zealand Society of Nuclear Medicine Inc

The significance of Good Chair as part of children’s school and home environment in the preventive treatment of body statistics distortions

OpenAIRE

Mirosław Mrozkowiak; Hanna Żukowska

2015-01-01

Mrozkowiak Mirosław, Żukowska Hanna. Znaczenie Dobrego Krzesła, jako elementu szkolnego i domowego środowiska ucznia, w profilaktyce zaburzeń statyki postawy ciała = The significance of Good Chair as part of children’s school and home environment in the preventive treatment of body statistics distortions. Journal of Education, Health and Sport. 2015;5(7):179-215. ISSN 2391-8306. DOI 10.5281/zenodo.19832 http://ojs.ukw.edu.pl/index.php/johs/article/view/2015%3B5%287%29%3A179-215 https:...

Can a significance test be genuinely Bayesian?

OpenAIRE

Pereira, Carlos A. de B.; Stern, Julio Michael; Wechsler, Sergio

2008-01-01

The Full Bayesian Significance Test, FBST, is extensively reviewed. Its test statistic, a genuine Bayesian measure of evidence, is discussed in detail. Its behavior in some problems of statistical inference like testing for independence in contingency tables is discussed.

Challenges (Obstacles) in Reaching Leadership Positions – Experiences of Women Professors at Novi Sad University Serbia

OpenAIRE

Andrić Marijana Mišić; Markov Slobodanka

2017-01-01

Underrepresentation of women in leadership positions in universities is a phenomenon present in most countries of the world, with some significant differences. In our work we focused on obstacles that women professors in Novi Sad University (Serbia) faced in reaching leadership positions. Analysis is based on qualitative research using a semi structured interview, statistical data and selected secondary sources. Obstacles, mentorship and networking have been researched from an idiographic per...

Testing for Statistical Discrimination based on Gender

DEFF Research Database (Denmark)

Lesner, Rune Vammen

. It is shown that the implications of both screening discrimination and stereotyping are consistent with observable wage dynamics. In addition, it is found that the gender wage gap decreases in tenure but increases in job transitions and that the fraction of women in high-ranking positions within a firm does......This paper develops a model which incorporates the two most commonly cited strands of the literature on statistical discrimination, namely screening discrimination and stereotyping. The model is used to provide empirical evidence of statistical discrimination based on gender in the labour market...... not affect the level of statistical discrimination by gender....

Expression and prognostic significance of lysozyme in male breast cancer

International Nuclear Information System (INIS)

Serra, Carlos; Baltasar, Aniceto; Medrano, Justo; Vizoso, Francisco; Alonso, Lorena; Rodríguez, Juan C; González, Luis O; Fernández, María; Lamelas, María L; Sánchez, Luis M; García-Muñiz, José L

2002-01-01

Lysozyme, one of the major protein components of human milk that is also synthesized by a significant percentage of breast carcinomas, is associated with lesions that have a favorable outcome in female breast cancer. Here we evaluate the expression and prognostic value of lysozyme in male breast cancer (MBC). Lysozyme expression was examined by immunohistochemical methods in a series of 60 MBC tissue sections and in 15 patients with gynecomastia. Staining was quantified using the HSCORE (histological score) system, which considers both the intensity and the percentage of cells staining at each intensity. Prognostic value of lysozyme was retrospectively evaluated by multivariate analysis taking into account conventional prognostic factors. Lysozyme immunostaining was negative in all cases of gynecomastia. A total of 27 of 60 MBC sections (45%) stained positively for this protein, but there were clear differences among them with regard to the intensity and percentage of stained cells. Statistical analysis showed that lysozyme HSCORE values in relation to age, tumor size, nodal status, histological grade, estrogen receptor status, metastasis and histological type did not increase the statistical significance. Univariate analysis confirmed that both nodal involvement and lysozyme values were significant predictors of short-term relapse-free survival. Multivariate analysis, according to Cox's regression model, also showed that nodal status and lysozyme levels were significant independent indicators of short-term relapse-free survival. Tumor expression of lysozyme is associated with lesions that have an unfavorable outcome in male breast cancer. This milk protein may be a new prognostic factor in patients with breast cancer

A study of requested CT head examinations and their positive yield rate

International Nuclear Information System (INIS)

Coakley, K.S.

2004-01-01

Full text: Requests for CT examinations are ever increasing, partly due to the excellent clinical information they can provide for patient management and partly due to a perceived need for 'evidence' that everything has been done to diagnose a patient correctly. This has led to many CT examinations being done on patients where many of the radiology community does not necessarily feel CT will yield a positive finding, i.e. in their eyes - a possible unjustified use of radiation. To determine whether this was in fact true, or merely a perception, a study was performed by medical imaging and physics staff at the Royal Brisbane Hospital to determine statistics of positive yield for CT head exams. 600 CT head examinations from the Emergency Department at the Royal Brisbane Hospital were retrospectively examined and their findings were tabulated under various clinical categories to determine positive yield statistics. These categories were also tabulated with the radiologists advice as to whether they would have expected a positive finding. For several categories the positive yield for CT head exams was so low as to be considered negligible. Other categories, although low were still considered significant. These will be presented to the emergency department along with a suggested protocol for requesting CT head exams. It was unfortunate that this study had to be performed to prove to clinical staff that medical imaging staff members do in general have an excellent idea of what will show up in an x-ray and what will not! However, it was useful to be able to categorise 'positive yield' statistics into such specific classes. The next step is to try and communicate these findings to staff to create more trust and better communication between departments. Copyright (2004) Australasian College of Physical Scientists and Engineers in Medicine

Placing symptoms in context: the role of contextual criteria in reducing false positives in Diagnostic and Statistical Manual of Mental Disorders diagnoses.

Science.gov (United States)

Wakefield, Jerome C; First, Michael B

2012-02-01

The Diagnostic and Statistical Manual of Mental Disorders (DSM) definition of mental disorder requires that symptoms be caused by a dysfunction in the individual; when dysfunction is absent, symptoms represent normal-range distress or eccentricity and, if diagnosed as a mental disorder, are false positives. We hypothesized that because of psychiatry's lack of direct laboratory tests to distinguish dysfunction from normal-range distress, the context in which symptoms occur (eg, lack of imminent danger in a panic attack) is often essential to determining whether symptoms are caused by a dysfunction. If this is right, then the DSM diagnostic criteria should include many contextual criteria added to symptom syndromes to prevent dysfunction false positives. Despite their potential importance, such contextual criteria have not been previously reviewed. We, thus, systematically reviewed DSM categories to establish the extent of such uses of contextual criteria and created a typology of such uses. Of 111 sampled categories, 68 (61%) used context to prevent dysfunction false positives. Contextual criteria fell into 7 types: (1) exclusion of specific false-positive scenarios; (2) requiring that patients experience preconditions for normal responses (eg, requiring that individuals experience adequate sexual stimulation before being diagnosed with sexual dysfunctions); (3) requiring that symptoms be disproportionate relative to circumstances; (4) for childhood disorders, requiring that symptoms be developmentally inappropriate; (5) requiring that symptoms occur in multiple contexts; (6) requiring a substantial discrepancy between beliefs and reality; and (7) a residual category. Most DSM categories include contextual criteria to eliminate false-positive diagnoses and increase validity of descriptive criteria. Future revisions should systematically evaluate each category's need for contextual criteria. Copyright © 2012 Elsevier Inc. All rights reserved.

The Statistical Fermi Paradox

Science.gov (United States)

Maccone, C.

In this paper is provided the statistical generalization of the Fermi paradox. The statistics of habitable planets may be based on a set of ten (and possibly more) astrobiological requirements first pointed out by Stephen H. Dole in his book Habitable planets for man (1964). The statistical generalization of the original and by now too simplistic Dole equation is provided by replacing a product of ten positive numbers by the product of ten positive random variables. This is denoted the SEH, an acronym standing for “Statistical Equation for Habitables”. The proof in this paper is based on the Central Limit Theorem (CLT) of Statistics, stating that the sum of any number of independent random variables, each of which may be ARBITRARILY distributed, approaches a Gaussian (i.e. normal) random variable (Lyapunov form of the CLT). It is then shown that: 1. The new random variable NHab, yielding the number of habitables (i.e. habitable planets) in the Galaxy, follows the log- normal distribution. By construction, the mean value of this log-normal distribution is the total number of habitable planets as given by the statistical Dole equation. 2. The ten (or more) astrobiological factors are now positive random variables. The probability distribution of each random variable may be arbitrary. The CLT in the so-called Lyapunov or Lindeberg forms (that both do not assume the factors to be identically distributed) allows for that. In other words, the CLT "translates" into the SEH by allowing an arbitrary probability distribution for each factor. This is both astrobiologically realistic and useful for any further investigations. 3. By applying the SEH it is shown that the (average) distance between any two nearby habitable planets in the Galaxy may be shown to be inversely proportional to the cubic root of NHab. This distance is denoted by new random variable D. The relevant probability density function is derived, which was named the "Maccone distribution" by Paul Davies in

Adjacent effect on positive charge transfer from radical cation of n-dodecane to scavenger studied by supbicosecond pulse radiolysis, statistical and Monte Carlo approach

International Nuclear Information System (INIS)

Saeki, A.; Tagawa, S.; Kozawa, T.; Yoshida, Y.

2003-01-01

Time-dependent behaviors of radical cation in n-dodecane in the presence of high-concentrated cation scavenger triethylamine were measured by subpicosecond pulse radiolysis system. The significant reduction of the initial yield in the optical density was observed. This reduction were not able to be explained by the first order rate constant. Therefore, we assumed that this phenomena occur due to the adjacent effect of the solute molecules. We approached this effect by the statistical model and configurational-bias Monte Carlo method. In both methods, we supposed a condition that the cation site in the radical cation is delocalized and will be scavenged rapidly within the time resolution if the solute molecules is adjacent to any sites of the solvent. In addition to the adjacent effect, the fact that a large part of the solvent molecules is excluded by the solute molecules especially at high concentration was taken into consideration. First, we formulated this effect by a statistical model. In addition to the above assumption, this model is based on the following assumption; the effects of molecule's shape, conformation and interaction among molecules were ignored and the aggregation of the solute molecules were treated randomly. As a result, the formula indicated good agreement with the experimental data. Second, as another approach, we adopted the configurational-bias Monte Carlo simulation to reproduce the liquid system. The OLPS model was used to describe the intermolecular and intramolecular potentials. The adjacent effect estimated by this method corresponded to the experimental data with a threshold of 0.5 nm. This value are close to a typical reaction radius. The average number of adjacent solvent molecules and the distribution of aggregated solute's number were also collected from the position data

Attentional control mediates the effect of social anxiety on positive affect☆

Science.gov (United States)

Morrison, Amanda S.; Heimberg, Richard G.

2015-01-01

The goal of the present studies was to examine whether attentional control, a self-regulatory attentional mechanism, mediates the effect of social anxiety on positive affect. We tested this mediation in two studies using undergraduate students selected to represent a broad range of severity of social anxiety. Self-report assessments of social anxiety, attentional control, and positive affect were collected in a cross-sectional design (Study 1) and in a longitudinal design with three assessment points (Study 2). Results of both studies supported the hypothesized mediational model. Specifically, social anxiety was inversely related to attentional control, which itself positively predicted positive affect. This mediation remained significant even when statistically controlling for the effects of depression. Additionally, the hypothesized model provided superior model fit to theoretically-grounded equivalent models in both studies. Implications of these findings for understanding diminished positive affect in social anxiety are discussed. PMID:23254261

The large break LOCA evaluation method with the simplified statistic approach

International Nuclear Information System (INIS)

Kamata, Shinya; Kubo, Kazuo

2004-01-01

USNRC published the Code Scaling, Applicability and Uncertainty (CSAU) evaluation methodology to large break LOCA which supported the revised rule for Emergency Core Cooling System performance in 1989. In USNRC regulatory guide 1.157, it is required that the peak cladding temperature (PCT) cannot exceed 2200deg F with high probability 95th percentile. In recent years, overseas countries have developed statistical methodology and best estimate code with the model which can provide more realistic simulation for the phenomena based on the CSAU evaluation methodology. In order to calculate PCT probability distribution by Monte Carlo trials, there are approaches such as the response surface technique using polynomials, the order statistics method, etc. For the purpose of performing rational statistic analysis, Mitsubishi Heavy Industries, LTD (MHI) tried to develop the statistic LOCA method using the best estimate LOCA code MCOBRA/TRAC and the simplified code HOTSPOT. HOTSPOT is a Monte Carlo heat conduction solver to evaluate the uncertainties of the significant fuel parameters at the PCT positions of the hot rod. The direct uncertainty sensitivity studies can be performed without the response surface because the Monte Carlo simulation for key parameters can be performed in short time using HOTSPOT. With regard to the parameter uncertainties, MHI established the treatment that the bounding conditions are given for LOCA boundary and plant initial conditions, the Monte Carlo simulation using HOTSPOT is applied to the significant fuel parameters. The paper describes the large break LOCA evaluation method with the simplified statistic approach and the results of the application of the method to the representative four-loop nuclear power plant. (author)

Comparison of shoulder positions at MR arthrography: change of labroligamentous complex shape and diagnosis of labral tears

International Nuclear Information System (INIS)

Kwak, Jin Young; Ha, Doo Hoe; Kim, Jeung Sook; Lee, Young Soo

2001-01-01

To compare the neutral, internal, and external rotation positions of the glenohumeral joint during magnetic resonance (MR) arthrography performed to assess changes in the shape of the labroligamentous complex (LLC) and in the labral tear. MR arthrography of the shoulder was retrospectively evaluated in 36 patients aged 14-66 (mean, 40) years. Fourteen cases were confirmed by arthroscopic surgery (7 SLAP lesions, 2 Bankart lesions, 1 both SLAP and Bankart lesions). Axial fat-suppressed T1-weighted spin-echo images were acquired with each shoulder in the neutral position, and with internal and external rotations. In each position, we measured the angle of rotation between the perpendicular line on the glenoid fossa and the long axis of the humeral head, analyzing the relationship between the rotational angle and changes in the shape of the LLC at each internal and external rotation, relative to the neutral position. In addition, labral tears in 14 arthroscopically confirmed joints were evaluated in each position. Mean angles of rotation relative to the neutral position were 44.1 and 45.3 degrees in internal and external rotation, respectively. Changes in the anterior LLC occurred in 25 and 24 cases of internal and external rotation, respectively. There was a significantly meaningful relationship between rotational angle and changes in the shape of the anterior LLC during external rotation, and when this changes was noticed, the rotational angle was wider (p<0.05). The posterior LLC changed in shape in 13 and 16 cases of internal and external rotation, respectively, but changes according to the angle of rotation were not statistically significant. In arthroscopically confirmed joints, diagnosis of the eight SLAP lesions at external rotation tended to become more accurate, but no statistically significant differences were noted (p=0.07). Two Bankart lesions were interpreted as a tear in all three positions, and one other such lesion was interpreted as a tear in the

Statistics for experimentalists

CERN Document Server

Cooper, B E

2014-01-01

Statistics for Experimentalists aims to provide experimental scientists with a working knowledge of statistical methods and search approaches to the analysis of data. The book first elaborates on probability and continuous probability distributions. Discussions focus on properties of continuous random variables and normal variables, independence of two random variables, central moments of a continuous distribution, prediction from a normal distribution, binomial probabilities, and multiplication of probabilities and independence. The text then examines estimation and tests of significance. Topics include estimators and estimates, expected values, minimum variance linear unbiased estimators, sufficient estimators, methods of maximum likelihood and least squares, and the test of significance method. The manuscript ponders on distribution-free tests, Poisson process and counting problems, correlation and function fitting, balanced incomplete randomized block designs and the analysis of covariance, and experiment...

Computerized photogrammetry used to calculate the brow position index.

Science.gov (United States)

Naif-de-Andrade, Naif Thadeu; Hochman, Bernardo; Naif-de-Andrade, Camila Zirlis; Ferreira, Lydia Masako

2012-10-01

The orbital region is of vital importance to facial expression. Brow ptosis, besides having an impact on facial harmony, is a sign of aging. Various surgical techniques have been developed to increase the efficacy of brow-lift surgery. However, no consensus method exists for an objective measurement of the eyebrow position due to the curvature of the face. Therefore, this study aimed to establish a method for measuring the eyebrow position using computerized photogrammetry. For this study, 20 orbital regions of 10 volunteers were measured by direct anthropometry using a digital caliper and by indirect anthropometry (computerized photogrammetry) using standardized digital photographs. Lines, points, and distances were defined based on the position of the anthropometric landmarks endocanthion and exocanthion and then used to calculate the brow position index (BPI). Statistical analysis was performed using Student's t test with a significance level of 5 %. The BPI values obtained by computerized photogrammetric measurements did not differ significantly from those obtained by direct anthropometric measurements (p > 0.05). The mean BPI was 84.89 ± 10.30 for the computerized photogrammetric measurements and 85.27 ± 10.67 for the direct anthropometric measurements. The BPI defined in this study and obtained by computerized photogrammetry is a reproducible and efficient method for measuring the eyebrow position. This journal requires that authors assign a level of evidence to each article.

Side effects after myelography with Dimer Xsup(R) (Iocarmat) with subsequent positioning of the patients in the sitting or lying position

International Nuclear Information System (INIS)

Norstedt, M.

1982-01-01

92 patients were examined after lumbar myelography with the water-soluble contrast medium Iocarmat (Dimer Xsup(R)) in order to find out if side effects have any relation with the patient's position after the myelographic examination. In one group, the patients were laid with their upper part of the body positioned higher while the others were allowed to lie flat. The comparative investigation covering both groups of patients revealed the following results: 1) In 11% of the flat-lying patients there were generalised spasms which was not the case as far as the sitting patients were concerned. This is why the author advises against a flat positioning of the patient. 2) The frequency of headache decreased when the patients were lying flat which, however, does not mean a statistical significance. 3) Other side effects registered (myoclonus, tonic spasm in the legs, paraesthesia, increase in existing root pain and neck pain, nausea and vomiting) occurred in both groups nearly to the same extent, independently of the position of the patient. (orig./MG) [de

A Noise Trimming and Positional Significance of Transposon Insertion System to Identify Essential Genes in Yersinia pestis

Science.gov (United States)

Yang, Zheng Rong; Bullifent, Helen L.; Moore, Karen; Paszkiewicz, Konrad; Saint, Richard J.; Southern, Stephanie J.; Champion, Olivia L.; Senior, Nicola J.; Sarkar-Tyson, Mitali; Oyston, Petra C. F.; Atkins, Timothy P.; Titball, Richard W.

2017-02-01

Massively parallel sequencing technology coupled with saturation mutagenesis has provided new and global insights into gene functions and roles. At a simplistic level, the frequency of mutations within genes can indicate the degree of essentiality. However, this approach neglects to take account of the positional significance of mutations - the function of a gene is less likely to be disrupted by a mutation close to the distal ends. Therefore, a systematic bioinformatics approach to improve the reliability of essential gene identification is desirable. We report here a parametric model which introduces a novel mutation feature together with a noise trimming approach to predict the biological significance of Tn5 mutations. We show improved performance of essential gene prediction in the bacterium Yersinia pestis, the causative agent of plague. This method would have broad applicability to other organisms and to the identification of genes which are essential for competitiveness or survival under a broad range of stresses.

Salivary expression of soluble HER2 in breast cancer patients with positive and negative HER2 status

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Laidi F

2014-07-01

Full Text Available Fatna Laidi,1 Amal Bouziane,2 Amina Lakhdar,3 Samira Khabouze,3 Brahim Rhrab,3 Fatima Zaoui1 1Oral Biomechanics and Biotechnology Research Unit, Faculty of Dental Medicine, 2Department of Periodontology, Faculty of Dental Medicine, Biostatistical, Clinical and Epidemiological Research Laboratory, Faculty of Medicine and Pharmacy, 3Department of Obstetrics and Gynecology, Ibn Sina University Hospital, Rabat, Morocco Background: The aim of this study was to investigate the relationship between salivary concentration of the soluble fragment of the HER2 (human epidermal growth factor receptor protein and its status in mammary tissues. Methods: This case-control study was done in 27 breast cancer patients with no visible metastatic disease treated at the gynecology service, Maternity Souissi Hospital, Rabat, Morocco. Two groups were selected, ie, patients with positive and negative HER2 status in mammary tissue. The salivary HER2 protein concentration was assessed by enzyme-linked immunosorbent assay. The salivary HER2 concentration was compared between the HER2-positive and HER2-negative groups using the Mann-Whitney U test. A P-value <0.05 was considered to be statistically significant. Results: No statistically significant difference in salivary HER2 protein expression was found between the case and control groups. There was also no significant difference in clinical characteristics according to positive and negative HER2 status (P>0.05, except for the progesterone hormone receptor which was statistically significant in both the case and control groups (P=0.047. Conclusion: According to our data, salivary expression of the HER2 receptor may not be a reliable alternative to tissue assessment. Keywords: breast cancer, HER2, saliva, diagnosis

Mobile Digital Applications for Farmers to Transform Agriculture Statistics from the Bottom Up

Science.gov (United States)

Brown, M. E.; Grace, K.; Sahajpal, R.; Nagol, J. R.

2017-12-01

As the global population continues to grow and become more wealthy, the amount of food humanity consumes should also grow, particularly in low income countries that are currently consuming significantly less per capita than is optimal. Reducing yield gaps in low income regions can increase overall agricultural production and pull populations conducting subsistence agriculture in rural areas out of poverty. Investment in the transformation of agricultural value chain to include low income farmers can have significant positive impacts on communities and individuals participating, as well as the resilience of the food system itself. A major obstacle to improving the effectiveness of policies and interventions in the rural agriculture sector is a lack of information about the socio-economic, agricultural production and environmental conditions experienced by farmers as they participate in agriculture. There is a significant lack of high quality statistics that can be used to develop effective agricultural development programs. In today's world of online mapping software, accurate global positioning systems that allow instant, affordable location retrieval and growing mobile connectivity, what is needed is community- or even field-level information. Given the enormous geographic, economic and cultural diversity of even small countries, why settle for national statistics? The kind of information that is needed is at the field and farmer level, not the country level. This paper reviews ways geospatial and information technology can be used to generate farmer-specific information across all countries participating in agriculture.

Robot Trajectories Comparison: A Statistical Approach

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A. Ansuategui

2014-01-01

Full Text Available The task of planning a collision-free trajectory from a start to a goal position is fundamental for an autonomous mobile robot. Although path planning has been extensively investigated since the beginning of robotics, there is no agreement on how to measure the performance of a motion algorithm. This paper presents a new approach to perform robot trajectories comparison that could be applied to any kind of trajectories and in both simulated and real environments. Given an initial set of features, it automatically selects the most significant ones and performs a statistical comparison using them. Additionally, a graphical data visualization named polygraph which helps to better understand the obtained results is provided. The proposed method has been applied, as an example, to compare two different motion planners, FM2 and WaveFront, using different environments, robots, and local planners.

Robot Trajectories Comparison: A Statistical Approach

Science.gov (United States)

Ansuategui, A.; Arruti, A.; Susperregi, L.; Yurramendi, Y.; Jauregi, E.; Lazkano, E.; Sierra, B.

2014-01-01

The task of planning a collision-free trajectory from a start to a goal position is fundamental for an autonomous mobile robot. Although path planning has been extensively investigated since the beginning of robotics, there is no agreement on how to measure the performance of a motion algorithm. This paper presents a new approach to perform robot trajectories comparison that could be applied to any kind of trajectories and in both simulated and real environments. Given an initial set of features, it automatically selects the most significant ones and performs a statistical comparison using them. Additionally, a graphical data visualization named polygraph which helps to better understand the obtained results is provided. The proposed method has been applied, as an example, to compare two different motion planners, FM2 and WaveFront, using different environments, robots, and local planners. PMID:25525618

On two methods of statistical image analysis

NARCIS (Netherlands)

Missimer, J; Knorr, U; Maguire, RP; Herzog, H; Seitz, RJ; Tellman, L; Leenders, K.L.

1999-01-01

The computerized brain atlas (CBA) and statistical parametric mapping (SPM) are two procedures for voxel-based statistical evaluation of PET activation studies. Each includes spatial standardization of image volumes, computation of a statistic, and evaluation of its significance. In addition,

Statistics Using Just One Formula

Science.gov (United States)

Rosenthal, Jeffrey S.

2018-01-01

This article advocates that introductory statistics be taught by basing all calculations on a single simple margin-of-error formula and deriving all of the standard introductory statistical concepts (confidence intervals, significance tests, comparisons of means and proportions, etc) from that one formula. It is argued that this approach will…

Statistics Anxiety among Postgraduate Students

Science.gov (United States)

Koh, Denise; Zawi, Mohd Khairi

2014-01-01

Most postgraduate programmes, that have research components, require students to take at least one course of research statistics. Not all postgraduate programmes are science based, there are a significant number of postgraduate students who are from the social sciences that will be taking statistics courses, as they try to complete their…

Lagrangian statistics across the turbulent-nonturbulent interface in a turbulent plane jet.

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Taveira, Rodrigo R; Diogo, José S; Lopes, Diogo C; da Silva, Carlos B

2013-10-01

Lagrangian statistics from millions of particles are used to study the turbulent entrainment mechanism in a direct numerical simulation of a turbulent plane jet at Re(λ) ≈ 110. The particles (tracers) are initially seeded at the irrotational region of the jet near the turbulent shear layer and are followed as they are drawn into the turbulent region across the turbulent-nonturbulent interface (TNTI), allowing the study of the enstrophy buildup and thereby characterizing the turbulent entrainment mechanism in the jet. The use of Lagrangian statistics following fluid particles gives a more correct description of the entrainment mechanism than in previous works since the statistics in relation to the TNTI position involve data from the trajectories of the entraining fluid particles. The Lagrangian statistics for the particles show the existence of a velocity jump and a characteristic vorticity jump (with a thickness which is one order of magnitude greater than the Kolmogorov microscale), in agreement with previous results using Eulerian statistics. The particles initially acquire enstrophy by viscous diffusion and later by enstrophy production, which becomes "active" only deep inside the turbulent region. Both enstrophy diffusion and production near the TNTI differ substantially from inside the turbulent region. Only about 1% of all particles find their way into pockets of irrotational flow engulfed into the turbulent shear layer region, indicating that "engulfment" is not significant for the present flow, indirectly suggesting that the entrainment is largely due to "nibbling" small-scale mechanisms acting along the entire TNTI surface. Probability density functions of particle positions suggests that the particles spend more time crossing the region near the TNTI than traveling inside the turbulent region, consistent with the particles moving tangent to the interface around the time they cross it.

Predicting axillary lymph node metastasis from kinetic statistics of DCE-MRI breast images

Science.gov (United States)

Ashraf, Ahmed B.; Lin, Lilie; Gavenonis, Sara C.; Mies, Carolyn; Xanthopoulos, Eric; Kontos, Despina

2012-03-01

The presence of axillary lymph node metastases is the most important prognostic factor in breast cancer and can influence the selection of adjuvant therapy, both chemotherapy and radiotherapy. In this work we present a set of kinetic statistics derived from DCE-MRI for predicting axillary node status. Breast DCE-MRI images from 69 women with known nodal status were analyzed retrospectively under HIPAA and IRB approval. Axillary lymph nodes were positive in 12 patients while 57 patients had no axillary lymph node involvement. Kinetic curves for each pixel were computed and a pixel-wise map of time-to-peak (TTP) was obtained. Pixels were first partitioned according to the similarity of their kinetic behavior, based on TTP values. For every kinetic curve, the following pixel-wise features were computed: peak enhancement (PE), wash-in-slope (WIS), wash-out-slope (WOS). Partition-wise statistics for every feature map were calculated, resulting in a total of 21 kinetic statistic features. ANOVA analysis was done to select features that differ significantly between node positive and node negative women. Using the computed kinetic statistic features a leave-one-out SVM classifier was learned that performs with AUC=0.77 under the ROC curve, outperforming the conventional kinetic measures, including maximum peak enhancement (MPE) and signal enhancement ratio (SER), (AUCs of 0.61 and 0.57 respectively). These findings suggest that our DCE-MRI kinetic statistic features can be used to improve the prediction of axillary node status in breast cancer patients. Such features could ultimately be used as imaging biomarkers to guide personalized treatment choices for women diagnosed with breast cancer.

Whole-body computed tomography in trauma patients: optimization of the patient scanning position significantly shortens examination time while maintaining diagnostic image quality

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Hickethier T

2018-05-01

Full Text Available Tilman Hickethier,1,* Kamal Mammadov,1,* Bettina Baeßler,1 Thorsten Lichtenstein,1 Jochen Hinkelbein,2 Lucy Smith,3 Patrick Sven Plum,4 Seung-Hun Chon,4 David Maintz,1 De-Hua Chang1 1Department of Radiology, University Hospital of Cologne, Cologne, Germany; 2Department of Anesthesiology and Intensive Care Medicine, University Hospital of Cologne, Cologne, Germany; 3Faculty of Medicine, Memorial University of Newfoundland, St. John’s, Canada; 4Department of General, Visceral and Cancer Surgery, University Hospital of Cologne, Cologne, Germany *These authors contributed equally to this work Background: The study was conducted to compare examination time and artifact vulnerability of whole-body computed tomographies (wbCTs for trauma patients using conventional or optimized patient positioning. Patients and methods: Examination time was measured in 100 patients scanned with conventional protocol (Group A: arms positioned alongside the body for head and neck imaging and over the head for trunk imaging and 100 patients scanned with optimized protocol (Group B: arms flexed on a chest pillow without repositioning. Additionally, influence of two different scanning protocols on image quality in the most relevant body regions was assessed by two blinded readers. Results: Total wbCT duration was about 35% or 3:46 min shorter in B than in A. Artifacts in aorta (27 vs 6%, liver (40 vs 8% and spleen (27 vs 5% occurred significantly more often in B than in A. No incident of non-diagnostic image quality was reported, and no significant differences for lungs and spine were found. Conclusion: An optimized wbCT positioning protocol for trauma patients allows a significant reduction of examination time while still maintaining diagnostic image quality. Keywords: CT scan, polytrauma, acute care, time requirement, positioning

Hydration sites of unpaired RNA bases: a statistical analysis of the PDB structures

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Carugo Oliviero

2011-10-01

Full Text Available Abstract Background Hydration is crucial for RNA structure and function. X-ray crystallography is the most commonly used method to determine RNA structures and hydration and, therefore, statistical surveys are based on crystallographic results, the number of which is quickly increasing. Results A statistical analysis of the water molecule distribution in high-resolution X-ray structures of unpaired RNA nucleotides showed that: different bases have the same penchant to be surrounded by water molecules; clusters of water molecules indicate possible hydration sites, which, in some cases, match those of the major and minor grooves of RNA and DNA double helices; complex hydrogen bond networks characterize the solvation of the nucleotides, resulting in a significant rigidity of the base and its surrounding water molecules. Interestingly, the hydration sites around unpaired RNA bases do not match, in general, the positions that are occupied by the second nucleotide when the base-pair is formed. Conclusions The hydration sites around unpaired RNA bases were found. They do not replicate the atom positions of complementary bases in the Watson-Crick pairs.

[Longitudinal genetic effects on mandibular position of female twins from six to twelve years old].

Science.gov (United States)

Zhu, Chang-feng; Peng, Jing

2013-06-01

To find the longitudinal genetic effects on mandibular position in mixed dentition. The sample used in this study consisted of lateral cephalograms of eighty-nine pairs of female twins in Beijing. With a mixed longitudinal method, the effective twins were 183 pairs(monozygous 110 pairs and dizygous 73 ones). The genetic and environmental effects on mandibular position were analyzed by statistical methods in female twins from six to twelve years old. Statistical comparisons revealed significant (Pchin is the most subjective to environment change, then the mandibular angle, and the condyle is the least. Using N and S as references, the environmental influence on heights showed different order from the most to least changeable: The mandibular angle, the condyle and the chin. In later stage of our observation, the mandibular morphology and growth type might be family inherited. For environmental influences plays important roles on mandibular position, these findings can be used in orthodontic treatment planning.

North American Engineering, Procurement, Fabrication and Construction Worker Safety Climate Perception Affected by Job Position

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Clint Pinion

2018-04-01

Full Text Available Understanding and implementing the results of Safety Climate surveys can assist in decreasing occupational injuries and illnesses. The following article presents findings of a cross-sectional study that assessed the relationship between safety climate perceptions and job position among engineering, procurement, fabrication and construction (EPFC employees using a 15-item survey. Descriptive statistics (means and frequencies and an ANACOVA (analysis of covariance were performed on a saturated model. The study had a 62% response rate. Results indicate a statistically significant in mean safety climate scores between job position among EPFC employees when controlling for years in industry and location type (i.e., construction versus fabrication [F (9, 603 = 5.28, p < 0.0001, adjusted R-square = 0.07]. Employee perception of safety climate differed based on the employee’s job position (i.e., laborer, foreman, etc.. Project management reported the highest safety climate scores (0.91, followed by supervisors (0.86, technical support employees and foremen (0.84 and laborers (0.81.

Challenges (Obstacles in Reaching Leadership Positions – Experiences of Women Professors at Novi Sad University Serbia

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Andrić Marijana Mišić

2017-12-01

Full Text Available Underrepresentation of women in leadership positions in universities is a phenomenon present in most countries of the world, with some significant differences. In our work we focused on obstacles that women professors in Novi Sad University (Serbia faced in reaching leadership positions. Analysis is based on qualitative research using a semi structured interview, statistical data and selected secondary sources. Obstacles, mentorship and networking have been researched from an idiographic perspective (reflection and the personal experience of the women at Novi Sad University. Results indicate a significant underrepresentation of women in leadership positions at Novi Sad University. Findings point to a general pattern: the more power and authority the leadership position holds, the scarcer the number of women participating in it. According to interviewees’ statements the patriarchal value system makes the leadership positions difficult to attain for women. Interview analysis also suggests additional limiting factors, such as lack of mentorship and inadequate networking, acting as inhibitors in reaching leadership positions.

THE TRADE POSITION OF POLAND IN THE ICT SERVICES SECTOR

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Sylwia Talar

2016-09-01

Full Text Available The paper includes analysis and assessment of trade in the ICT services performance of Poland. This study is looked at the trade position, essentially on the basis of the share in the world ICT services exports, revealed comparative advantage (RCA, and trade coverage ratio. It also identifies trends of the world trade in the ICT services. The statistics are derived from the basis of UNCTAD and Eurostat. International trade in the ICT ser-vices sector has specific characteristics and the interpretation of results of this trade is to take account of the particular nature of the ICT services. Poland is currently not revealed comparative advantage in the ICT services exports, but has had positive balance. Practically all trade indicators for Poland show very strong growth, which indicate a significant improvement in its ICT services trade position.

Strategies for Proximal Femoral Nailing of Unstable Intertrochanteric Fractures: Lateral Decubitus Position or Traction Table.

Science.gov (United States)

Sonmez, Mesut Mehmet; Camur, Savas; Erturer, Erden; Ugurlar, Meric; Kara, Adnan; Ozturk, Irfan

2017-03-01

The aim of this prospective randomized study was to compare the traction table and lateral decubitus position techniques in the management of unstable intertrochanteric fractures. Eighty-two patients with unstable intertrochanteric fractures between 2011 and 2013 were included in this study. All patients were treated surgically with the Proximal Femoral Nail Antirotation implant (DePuy Synthes). Patients were randomized to undergo the procedure in the lateral decubitus position (42 patients) or with the use of a traction table (40 patients). Patients whose procedure was not performed entirely with a semi-invasive method or who required the use of additional fixation materials, such as cables, were excluded from the study. The groups were compared on the basis of the setup time, surgical time, fluoroscopic exposure time, tip-to-apex distance, collodiaphyseal angle, and modified Baumgaertner criteria for radiologic reduction. The setup time, surgical time, and fluoroscopic exposure time were lower and the differences were statistically significant in the lateral decubitus group compared with the traction table group. The collodiaphyseal angles were significantly different between the groups in favor of the lateral decubitus method. The tip-to-apex distance and the classification of reduction according to the modified Baumgaertner criteria did not demonstrate a statistically significant difference between the groups. The lateral decubitus position is used for most open procedures of the hip. We found that this position facilitates exposure for the surgical treatment of unstable intertrochanteric fractures and has advantages over the traction table in terms of set up time, surgical time and fluoroscopic exposure time.

Distance matters. Assessing socioeconomic impacts of the Dukovany nuclear power plant in the Czech Republic: Local perceptions and statistical evidence

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Frantál Bohumil

2016-03-01

Full Text Available The effect of geographical distance on the extent of socioeconomic impacts of the Dukovany nuclear power plant in the Czech Republic is assessed by combining two different research approaches. First, we survey how people living in municipalities in the vicinity of the power plant perceive impacts on their personal quality of life. Second, we explore the effects of the power plant on regional development by analysing long-term statistical data about the unemployment rate, the share of workers in the energy sector and overall job opportunities in the respective municipalities. The results indicate that the power plant has had significant positive impacts on surrounding communities both as perceived by residents and as evidenced by the statistical data. The level of impacts is, however, significantly influenced by the spatial and social distances of communities and individuals from the power plant. The perception of positive impacts correlates with geographical proximity to the power plant, while the hypothetical distance where positive effects on the quality of life are no longer perceived was estimated at about 15 km. Positive effects are also more likely to be reported by highly educated, young and middle-aged and economically active persons, whose work is connected to the power plant.

Can slide positivity rates predict malaria transmission?

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Bi Yan

2012-04-01

Full Text Available Abstract Background Malaria is a significant threat to population health in the border areas of Yunnan Province, China. How to accurately measure malaria transmission is an important issue. This study aimed to examine the role of slide positivity rates (SPR in malaria transmission in Mengla County, Yunnan Province, China. Methods Data on annual malaria cases, SPR and socio-economic factors for the period of 1993 to 2008 were obtained from the Center for Disease Control and Prevention (CDC and the Bureau of Statistics, Mengla, China. Multiple linear regression models were conducted to evaluate the relationship between socio-ecologic factors and malaria incidence. Results The results show that SPR was significantly positively associated with the malaria incidence rates. The SPR (β = 1.244, p = 0.000 alone and combination (SPR, β = 1.326, p  Conclusion SPR is a strong predictor of malaria transmission, and can be used to improve the planning and implementation of malaria elimination programmes in Mengla and other similar locations. SPR might also be a useful indicator of malaria early warning systems in China.

Statistical Reporting Errors and Collaboration on Statistical Analyses in Psychological Science.

Science.gov (United States)

Veldkamp, Coosje L S; Nuijten, Michèle B; Dominguez-Alvarez, Linda; van Assen, Marcel A L M; Wicherts, Jelte M

2014-01-01

Statistical analysis is error prone. A best practice for researchers using statistics would therefore be to share data among co-authors, allowing double-checking of executed tasks just as co-pilots do in aviation. To document the extent to which this 'co-piloting' currently occurs in psychology, we surveyed the authors of 697 articles published in six top psychology journals and asked them whether they had collaborated on four aspects of analyzing data and reporting results, and whether the described data had been shared between the authors. We acquired responses for 49.6% of the articles and found that co-piloting on statistical analysis and reporting results is quite uncommon among psychologists, while data sharing among co-authors seems reasonably but not completely standard. We then used an automated procedure to study the prevalence of statistical reporting errors in the articles in our sample and examined the relationship between reporting errors and co-piloting. Overall, 63% of the articles contained at least one p-value that was inconsistent with the reported test statistic and the accompanying degrees of freedom, and 20% of the articles contained at least one p-value that was inconsistent to such a degree that it may have affected decisions about statistical significance. Overall, the probability that a given p-value was inconsistent was over 10%. Co-piloting was not found to be associated with reporting errors.

Feelings of hopelessness in stable HIV-positive patients on antiretrovirals

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M Y H Moosa

2010-04-01

Full Text Available Aim. The coping skills and styles individuals utilise to deal with the stress of HIV infection greatly influence the psychological impact of this illness and potential consequent feelings of hopelessness. The aim of this study was to describe levels of hopelessness in a group of stable, non-depressed HIV-positive patients receiving antiretroviral therapy, and factors associated with hopelessness. Method. Thirty randomly selected non-depressed patients (according to Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV criteria were included in this study. Demographic and other data were obtained from all subjects, who also completed the Beck’s Hopelessness Scale (BHS. The 20 true-false items of the BHS (29 measured three major aspects of hopelessness, which was interpreted on the total scale score as follows: ≤3 minimal, and >3 significant. Results. The study population comprised 30 patients with a mean age of 37.9 years (standard error (SE 1.18 ( range 28 - 51 years. The mean BHS score was 4.03 (SE 0.55, with a range from 0 to 12. There were no statistically significant correlations between BHS scores of the study population and gender, marital status, employment status, level of education, years since the diagnosis of HIV, or number of children (p>0.05. Eighteen subjects (60% scored 3 or less on the BHS, considered minimal levels of hopelessness. However, 12 (40% scored more than 3, which is considered significant; of these 23% had scores of 7 or more. There was no statistically significant association between BHS scores and gender, employment status, level of education, number of children or number of years since diagnosis (p>0.05. However, patients who were married or living with partners were statistically more likely to score higher on the hopelessness scale compared with those who were single (p

The choice of statistical methods for comparisons of dosimetric data in radiotherapy

International Nuclear Information System (INIS)

Chaikh, Abdulhamid; Giraud, Jean-Yves; Perrin, Emmanuel; Bresciani, Jean-Pierre; Balosso, Jacques

2014-01-01

-corrected methods as compared to the reference method. Spearman’s and Kendall’s rank tests indicated a positive correlation between the doses calculated with the different methods. This paper illustrates and justifies the use of statistical tests and graphical representations for dosimetric comparisons in radiotherapy. The statistical analysis shows the significance of dose differences resulting from two or more techniques in radiotherapy

Confidence Intervals: From tests of statistical significance to confidence intervals, range hypotheses and substantial effects

Directory of Open Access Journals (Sweden)

Dominic Beaulieu-Prévost

2006-03-01

Full Text Available For the last 50 years of research in quantitative social sciences, the empirical evaluation of scientific hypotheses has been based on the rejection or not of the null hypothesis. However, more than 300 articles demonstrated that this method was problematic. In summary, null hypothesis testing (NHT is unfalsifiable, its results depend directly on sample size and the null hypothesis is both improbable and not plausible. Consequently, alternatives to NHT such as confidence intervals (CI and measures of effect size are starting to be used in scientific publications. The purpose of this article is, first, to provide the conceptual tools necessary to implement an approach based on confidence intervals, and second, to briefly demonstrate why such an approach is an interesting alternative to an approach based on NHT. As demonstrated in the article, the proposed CI approach avoids most problems related to a NHT approach and can often improve the scientific and contextual relevance of the statistical interpretations by testing range hypotheses instead of a point hypothesis and by defining the minimal value of a substantial effect. The main advantage of such a CI approach is that it replaces the notion of statistical power by an easily interpretable three-value logic (probable presence of a substantial effect, probable absence of a substantial effect and probabilistic undetermination. The demonstration includes a complete example.

Clinical significance of coryneform Gram-positive rods from blood identified by MALDI-TOF mass spectrometry and their susceptibility profiles - a retrospective chart review.

Science.gov (United States)

Mushtaq, Ammara; Chen, Derrick J; Strand, Gregory J; Dylla, Brenda L; Cole, Nicolynn C; Mandrekar, Jayawant; Patel, Robin

2016-07-01

With the advent of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), most Gram-positive rods (GPRs) are readily identified; however, their clinical relevance in blood cultures remains unclear. Herein, we assessed the clinical significance of GPRs isolated from blood and identified in the era of MALDI-TOF MS. A retrospective chart review of patients presenting to the Mayo Clinic, Rochester, MN, from January 1, 2013, to October 13, 2015, was performed. Any episode of a positive blood culture for a GPR was included. We assessed the number of bottles positive for a given isolate, time to positivity of blood cultures, patient age, medical history, interpretation of culture results by the healthcare team and whether infectious diseases consultation was obtained. We also evaluated the susceptibility profiles of a larger collection of GPRs tested in the clinical microbiology laboratory of the Mayo Clinic, Rochester, MN from January 1, 2013, to October 31, 2015. There were a total of 246 GPRs isolated from the blood of 181 patients during the study period. 56% (n = 101) were deemed contaminants by the healthcare team and were not treated; 33% (n = 59) were clinically determined to represent true bacteremia and were treated; and 8% (n = 14) were considered of uncertain significance, with patients prescribed treatment regardless. Patient characteristics associated with an isolate being treated on univariate analysis included younger age (P = 0.02), identification to the species level (P = 0.02), higher number of positive blood culture sets (P < 0.0001), lower time to positivity (P < 0.0001), immunosuppression (P = 0.03), and recommendation made by an infectious disease consultant (P = 0.0005). On multivariable analysis, infectious diseases consultation (P = 0.03), higher number of positive blood culture sets (P = 0.0005) and lower time to positivity (P = 0.03) were associated with an isolate being treated. 100, 83, 48 and 34% of GPRs

Statistics 101 for Radiologists.

Science.gov (United States)

Anvari, Arash; Halpern, Elkan F; Samir, Anthony E

2015-10-01

Diagnostic tests have wide clinical applications, including screening, diagnosis, measuring treatment effect, and determining prognosis. Interpreting diagnostic test results requires an understanding of key statistical concepts used to evaluate test efficacy. This review explains descriptive statistics and discusses probability, including mutually exclusive and independent events and conditional probability. In the inferential statistics section, a statistical perspective on study design is provided, together with an explanation of how to select appropriate statistical tests. Key concepts in recruiting study samples are discussed, including representativeness and random sampling. Variable types are defined, including predictor, outcome, and covariate variables, and the relationship of these variables to one another. In the hypothesis testing section, we explain how to determine if observed differences between groups are likely to be due to chance. We explain type I and II errors, statistical significance, and study power, followed by an explanation of effect sizes and how confidence intervals can be used to generalize observed effect sizes to the larger population. Statistical tests are explained in four categories: t tests and analysis of variance, proportion analysis tests, nonparametric tests, and regression techniques. We discuss sensitivity, specificity, accuracy, receiver operating characteristic analysis, and likelihood ratios. Measures of reliability and agreement, including κ statistics, intraclass correlation coefficients, and Bland-Altman graphs and analysis, are introduced. © RSNA, 2015.

Positive projections of symmetric matrices and Jordan algebras

DEFF Research Database (Denmark)

Fuglede, Bent; Jensen, Søren Tolver

2013-01-01

An elementary proof is given that the projection from the space of all symmetric p×p matrices onto a linear subspace is positive if and only if the subspace is a Jordan algebra. This solves a problem in a statistical model.......An elementary proof is given that the projection from the space of all symmetric p×p matrices onto a linear subspace is positive if and only if the subspace is a Jordan algebra. This solves a problem in a statistical model....

Preventing statistical errors in scientific journals.

NARCIS (Netherlands)

Nuijten, M.B.

2016-01-01

There is evidence for a high prevalence of statistical reporting errors in psychology and other scientific fields. These errors display a systematic preference for statistically significant results, distorting the scientific literature. There are several possible causes for this systematic error

Basics of statistical physics

CERN Document Server

Müller-Kirsten, Harald J W

2013-01-01

Statistics links microscopic and macroscopic phenomena, and requires for this reason a large number of microscopic elements like atoms. The results are values of maximum probability or of averaging. This introduction to statistical physics concentrates on the basic principles, and attempts to explain these in simple terms supplemented by numerous examples. These basic principles include the difference between classical and quantum statistics, a priori probabilities as related to degeneracies, the vital aspect of indistinguishability as compared with distinguishability in classical physics, the differences between conserved and non-conserved elements, the different ways of counting arrangements in the three statistics (Maxwell-Boltzmann, Fermi-Dirac, Bose-Einstein), the difference between maximization of the number of arrangements of elements, and averaging in the Darwin-Fowler method. Significant applications to solids, radiation and electrons in metals are treated in separate chapters, as well as Bose-Eins...

Parity and the spin{statistics connection

Indian Academy of Sciences (India)

A simple demonstration of the spin-statistics connection for general causal fields is obtained by using the parity operation to exchange spatial coordinates in the scalar product of a locally commuting field operator, evaluated at position x, with the same field operator evaluated at -x, at equal times.

Renyi statistics in equilibrium statistical mechanics

International Nuclear Information System (INIS)

Parvan, A.S.; Biro, T.S.

2010-01-01

The Renyi statistics in the canonical and microcanonical ensembles is examined both in general and in particular for the ideal gas. In the microcanonical ensemble the Renyi statistics is equivalent to the Boltzmann-Gibbs statistics. By the exact analytical results for the ideal gas, it is shown that in the canonical ensemble, taking the thermodynamic limit, the Renyi statistics is also equivalent to the Boltzmann-Gibbs statistics. Furthermore it satisfies the requirements of the equilibrium thermodynamics, i.e. the thermodynamical potential of the statistical ensemble is a homogeneous function of first degree of its extensive variables of state. We conclude that the Renyi statistics arrives at the same thermodynamical relations, as those stemming from the Boltzmann-Gibbs statistics in this limit.

Accuracy of maxillary positioning after standard and inverted orthognathic sequencing.

Science.gov (United States)

Ritto, Fabio G; Ritto, Thiago G; Ribeiro, Danilo Passeado; Medeiros, Paulo José; de Moraes, Márcio

2014-05-01

This study aimed to compare the accuracy of maxillary positioning after bimaxillary orthognathic surgery, using 2 sequences. A total of 80 cephalograms (40 preoperative and 40 postoperative) from 40 patients were analyzed. Group 1 included radiographs of patients submitted to conventional sequence, whereas group 2 patients were submitted to inverted sequence. The final position of the maxillary central incisor was obtained after vertical and horizontal measurements of the tracings, and it was compared with what had been planned. The null hypothesis, which stated that there would be no difference between the groups, was tested. After applying the Welch t test for comparison of mean differences between maxillary desired and achieved position, considering a statistical significance of 5% and a 2-tailed test, the null hypothesis was not rejected (P > .05). Thus, there was no difference in the accuracy of maxillary positioning between groups. Conventional and inverted sequencing proved to be reliable in positioning the maxilla after LeFort I osteotomy in bimaxillary orthognathic surgeries. Copyright © 2014 Elsevier Inc. All rights reserved.

Multi-Detector CT Findings of the Normal Appendix in Children: Evaluation of the Position, Diameter, and Presence or Absence of Intraluminal Gas

Energy Technology Data Exchange (ETDEWEB)

Park, Woon Ju; Kim, Jong Chul [Dept. of Radiology, Chungnam National University College of Medicine, Daejeon (Korea, Republic of)

2011-08-15

To assess the usefulness of multi-detector CT (MDCT) with multiplanar reformations (MPR) for the evaluation of the position, diameter and presence or absence of intraluminal gas in the normal appendix in children. From 2007 to 2010, we retrospectively analyzed the MDCT images of normal appendices in 133 children, and evaluated the position, diameter, and presence or absence of intraluminal gas in the appendix. Among the 133 appendices, type I (postileal and medial paracecal position) was found in 64 children, type II (subcecal position) in 22, type III (retrocecal and retrocolic/laterocolic position) in 15, type IV (preileal and medial colic position) in 16, and type V (lower pelvic position) in 16 children. The mean diameter was 5.8 mm {+-} 1.2 (SD) (range; 3.2-8.7 mm). There was a high correlation between the appendiceal diameter and age (p = 0.000).There was no statistically significant difference in the appendiceal diameter between boys and girls (p = 0.470). Intraluminal gas was found in 115 appendices and there was no statistically significant correlation between the appendiceal diameter and intraluminal gas (p = 0.502). The MDCT with MPR was useful for the evaluation of the normal appendices in children. The procedure may be useful for the diagnosis of equivocal or unusual appendicitis in children.

A comparative study on scapular static position between femaleswith and without generalized joint hyper mobility

Directory of Open Access Journals (Sweden)

Afsun Nodehi Moghadam

2012-08-01

Full Text Available Abstract Background: Generalized joint hyper mobility predisposes some individuals to a wide variety of musculoskeletal complaints. Given the critical role of scapular position in function of shoulder, the aim of this study was to compare scapular position between persons with and without general joint hyper mobility. Methods: By nonprobability sampling 30 hyper mobile persons at average of 22.86 ±2.77 years of age and 30 non hyper mobile persons (age 23.6 ± 2.73years through a case-control design participated in the study. Scapular position was assessed according to the lateral scapular slide test. Independent t test and repeated measures ANOVA were used to statistically analyze scapular position differences between groups.  Results: Compared to non hyper mobile persons, those with General joint hyper mobility demonstrated a significantly higher superior scapula slide in dependent arm position (p=0.03. However, no significant difference was found between another scores between two groups (p>0.05. Conclusion: The results suggest that altered scapular position may be an important aspect of General joint hyper mobility.

Identification of sequence motifs significantly associated with antisense activity

Directory of Open Access Journals (Sweden)

Peek Andrew S

2007-06-01

Full Text Available Abstract Background Predicting the suppression activity of antisense oligonucleotide sequences is the main goal of the rational design of nucleic acids. To create an effective predictive model, it is important to know what properties of an oligonucleotide sequence associate significantly with antisense activity. Also, for the model to be efficient we must know what properties do not associate significantly and can be omitted from the model. This paper will discuss the results of a randomization procedure to find motifs that associate significantly with either high or low antisense suppression activity, analysis of their properties, as well as the results of support vector machine modelling using these significant motifs as features. Results We discovered 155 motifs that associate significantly with high antisense suppression activity and 202 motifs that associate significantly with low suppression activity. The motifs range in length from 2 to 5 bases, contain several motifs that have been previously discovered as associating highly with antisense activity, and have thermodynamic properties consistent with previous work associating thermodynamic properties of sequences with their antisense activity. Statistical analysis revealed no correlation between a motif's position within an antisense sequence and that sequences antisense activity. Also, many significant motifs existed as subwords of other significant motifs. Support vector regression experiments indicated that the feature set of significant motifs increased correlation compared to all possible motifs as well as several subsets of the significant motifs. Conclusion The thermodynamic properties of the significantly associated motifs support existing data correlating the thermodynamic properties of the antisense oligonucleotide with antisense efficiency, reinforcing our hypothesis that antisense suppression is strongly associated with probe/target thermodynamics, as there are no enzymatic

Neutral vs positive oral contrast in diagnosing acute appendicitis with contrast-enhanced CT: sensitivity, specificity, reader confidence and interpretation time

Science.gov (United States)

Naeger, D M; Chang, S D; Kolli, P; Shah, V; Huang, W; Thoeni, R F

2011-01-01

Objective The study compared the sensitivity, specificity, confidence and interpretation time of readers of differing experience in diagnosing acute appendicitis with contrast-enhanced CT using neutral vs positive oral contrast agents. Methods Contrast-enhanced CT for right lower quadrant or right flank pain was performed in 200 patients with neutral and 200 with positive oral contrast including 199 with proven acute appendicitis and 201 with other diagnoses. Test set disease prevalence was 50%. Two experienced gastrointestinal radiologists, one fellow and two first-year residents blindly assessed all studies for appendicitis (2000 readings) and assigned confidence scores (1=poor to 4=excellent). Receiver operating characteristic (ROC) curves were generated. Total interpretation time was recorded. Each reader's interpretation with the two agents was compared using standard statistical methods. Results Average reader sensitivity was found to be 96% (range 91–99%) with positive and 95% (89–98%) with neutral oral contrast; specificity was 96% (92–98%) and 94% (90–97%). For each reader, no statistically significant difference was found between the two agents (sensitivities p-values >0.6; specificities p-values>0.08), in the area under the ROC curve (range 0.95–0.99) or in average interpretation times. In cases without appendicitis, positive oral contrast demonstrated improved appendix identification (average 90% vs 78%) and higher confidence scores for three readers. Average interpretation times showed no statistically significant differences between the agents. Conclusion Neutral vs positive oral contrast does not affect the accuracy of contrast-enhanced CT for diagnosing acute appendicitis. Although positive oral contrast might help to identify normal appendices, we continue to use neutral oral contrast given its other potential benefits. PMID:20959365

Representative volume size: A comparison of statistical continuum mechanics and statistical physics

Energy Technology Data Exchange (ETDEWEB)

AIDUN,JOHN B.; TRUCANO,TIMOTHY G.; LO,CHI S.; FYE,RICHARD M.

1999-05-01

In this combination background and position paper, the authors argue that careful work is needed to develop accurate methods for relating the results of fine-scale numerical simulations of material processes to meaningful values of macroscopic properties for use in constitutive models suitable for finite element solid mechanics simulations. To provide a definite context for this discussion, the problem is couched in terms of the lack of general objective criteria for identifying the size of the representative volume (RV) of a material. The objective of this report is to lay out at least the beginnings of an approach for applying results and methods from statistical physics to develop concepts and tools necessary for determining the RV size, as well as alternatives to RV volume-averaging for situations in which the RV is unmanageably large. The background necessary to understand the pertinent issues and statistical physics concepts is presented.

Statistics provide guidance for indigenous organic carbon detection on Mars missions.

Science.gov (United States)

Sephton, Mark A; Carter, Jonathan N

2014-08-01

Data from the Viking and Mars Science Laboratory missions indicate the presence of organic compounds that are not definitively martian in origin. Both contamination and confounding mineralogies have been suggested as alternatives to indigenous organic carbon. Intuitive thought suggests that we are repeatedly obtaining data that confirms the same level of uncertainty. Bayesian statistics may suggest otherwise. If an organic detection method has a true positive to false positive ratio greater than one, then repeated organic matter detection progressively increases the probability of indigeneity. Bayesian statistics also reveal that methods with higher ratios of true positives to false positives give higher overall probabilities and that detection of organic matter in a sample with a higher prior probability of indigenous organic carbon produces greater confidence. Bayesian statistics, therefore, provide guidance for the planning and operation of organic carbon detection activities on Mars. Suggestions for future organic carbon detection missions and instruments are as follows: (i) On Earth, instruments should be tested with analog samples of known organic content to determine their true positive to false positive ratios. (ii) On the mission, for an instrument with a true positive to false positive ratio above one, it should be recognized that each positive detection of organic carbon will result in a progressive increase in the probability of indigenous organic carbon being present; repeated measurements, therefore, can overcome some of the deficiencies of a less-than-definitive test. (iii) For a fixed number of analyses, the highest true positive to false positive ratio method or instrument will provide the greatest probability that indigenous organic carbon is present. (iv) On Mars, analyses should concentrate on samples with highest prior probability of indigenous organic carbon; intuitive desires to contrast samples of high prior probability and low prior

Kappa statistic to measure agreement beyond chance in free-response assessments.

Science.gov (United States)

Carpentier, Marc; Combescure, Christophe; Merlini, Laura; Perneger, Thomas V

2017-04-19

The usual kappa statistic requires that all observations be enumerated. However, in free-response assessments, only positive (or abnormal) findings are notified, but negative (or normal) findings are not. This situation occurs frequently in imaging or other diagnostic studies. We propose here a kappa statistic that is suitable for free-response assessments. We derived the equivalent of Cohen's kappa statistic for two raters under the assumption that the number of possible findings for any given patient is very large, as well as a formula for sampling variance that is applicable to independent observations (for clustered observations, a bootstrap procedure is proposed). The proposed statistic was applied to a real-life dataset, and compared with the common practice of collapsing observations within a finite number of regions of interest. The free-response kappa is computed from the total numbers of discordant (b and c) and concordant positive (d) observations made in all patients, as 2d/(b + c + 2d). In 84 full-body magnetic resonance imaging procedures in children that were evaluated by 2 independent raters, the free-response kappa statistic was 0.820. Aggregation of results within regions of interest resulted in overestimation of agreement beyond chance. The free-response kappa provides an estimate of agreement beyond chance in situations where only positive findings are reported by raters.

Influence of Near-Segment Positioning in a Rotationally Asymmetric Multifocal Intraocular Lens.

Science.gov (United States)

Song, In Seok; Yoon, Sam Young; Kim, Jae Yong; Kim, Myoung Joon; Tchah, Hungwon

2016-04-01

To compare visual performance and higher order aberrations (HOAs) based on the position of the near segment in eyes with rotationally asymmetric multifocal intraocular lenses (IOLs). Asymmetric multifocal IOLs (Lentis Mplus LS-313; Oculentis Optikgeräte GmbH, Wetzlar, Germany) were implanted with the near segment positioned either inferiorly, superiorly, or temporally. Uncorrected distance (UDVA), intermediate (UIVA), and near (UNVA) visual acuity, corrected distance visual acuity (CDVA), and distance-corrected intermediate (DCIVA) and near (DCNVA) visual acuity, contrast sensitivity, HOAs, and subjective symptom questionnaires were compared at 1 month postoperatively. Forty-five eyes from 45 patients were evaluated (n = 25, 9, and 11 eyes in the inferior, superior, and temporal groups, respectively). No significant differences in UDVA, UIVA, UNVA, CDVA, DCIVA, or DCNVA were found between the three groups (P > .05). The temporal group showed the best results in UDVA, CDVA, and DCNVA, but the inferior group showed the best results in DCIVA and UNVA and the superior group showed the best results in UIVA. Contrast sensitivity and the subjective symptom questionnaire also did not demonstrate any significant differences (P > .05). Total HOA and spherical aberration did not demonstrate any statistically significant differences (P > .05), but vertical coma and horizontal coma demonstrated significant differences based on near segment position (P < .001). The position of the near segment in eyes with rotationally asymmetric multifocal IOLs demonstrates no significant effect on visual performance. Copyright 2016, SLACK Incorporated.

The effect of lateral decubitus position on nocturnal intraocular pressure over a habitual 24-hour period in healthy adults.

Science.gov (United States)

Hao, Jie; Zhen, Yi; Wang, Hao; Yang, Diya; Wang, Ningli

2014-01-01

To investigate the effect of lateral decubitus position (LDP) on nocturnal intraocular pressure (IOP) and the effect of LDP on 24-hour habitual IOP pattern in healthy subjects. Intraocular pressure was measured every 2-hours using an Accupen Applanation Tonometer (Accutome, USA). During the diurnal period (7:30 am, 9:30 am, 11:30 am, 1:30 pm, 3:30 pm, 5:30 pm, 7:30 pm, and 9:30 pm), IOP was measured in the sitting position under bright light (500-1000 lux) after the subjects had been seated for 5 min. The nocturnal IOP was measured in the supine position, right LDP, and left LDP, with randomized sequences, under dim light (hour habitual IOP patterns were obtained according to the nocturnal position (supine, right LDP and left LDP) for either eye. Phour period, the effect of LDP on habitual IOP pattern was not statistically significant, although the mean nocturnal IOP and the diurnal-nocturnal IOP change for the right and the left eye in the LDP pattern was slightly higher than that in the sitting-supine pattern. Significant nocturnal IOP differences existed between the dependent eye and the supine, but did not occur consistently for all time points. Over a 24-hour period, the effect of LDP on habitual IOP pattern was not statistically significant in healthy subjects.

Prognostic significance of radionuclide-assessed diastolic function in hypertrophic cardiomyopathy

International Nuclear Information System (INIS)

Chikamori, T.; Dickie, S.; Poloniecki, J.D.; Myers, M.J.; Lavender, J.P.; McKenna, W.J.

1990-01-01

To evaluate the prognostic significance of diastolic function in hypertrophic cardiomyopathy (HC), technetium-99m gated equilibrium radionuclide angiography, acquired in list mode, was performed in 161 patients. Five diastolic indexes were calculated. During 3.0 +/- 1.9 years, 13 patients had disease-related deaths. With univariate analysis, these patients were younger (29 +/- 20 vs 42 +/- 16 years; p less than 0.05), had a higher incidence of syncope (p less than 0.025), dyspnea (p less than 0.001), reduced peak filling rate (2.9 +/- 0.9 vs 3.4 +/- 1.0 end-diastolic volume/s; p = 0.09) with increased relative filling volume during the rapid filling period (80 +/- 7 vs 75 +/- 12%; p = 0.06) and decreased atrial contribution (17 +/- 7 vs 22 +/- 11%; p = 0.07). Stepwise discriminant analysis revealed that young age at diagnosis, syncope at diagnosis, reduced peak ejection rate, positive family history, reduced peak filling rate, increased relative filling volume by peak filling rate and concentric left ventricular hypertrophy were the most statistically significant (p = 0.0001) predictors of disease-related death (sensitivity 92%, specificity 76%, accuracy 77%, positive predictive value 25%). Discriminant analysis excluding the diastolic indexes, however, showed similar predictability (sensitivity 92%, specificity 76%, accuracy 78%, positive predictive value 26%). To obtain more homogeneous groups for analysis, patients were classified as survivors or electrically unstable, including sudden death, out-of-hospital ventricular fibrillation and nonsustained ventricular tachycardia during 48-hour ambulatory electrocardiography, and heart failure death or cardiac transplant

High Prevalence and Significance of Hepatitis D Virus Infection among Treatment-Naïve HBsAg-Positive Patients in Northern Vietnam

Science.gov (United States)

Sy, Bui Tien; Ratsch, Boris A.; Toan, Nguyen Linh; Song, Le Huu; Wollboldt, Christian; Bryniok, Agnes; Nguyen, Hung Minh; Luong, Hoang Van; Velavan, Thirumalaisamy P.; Wedemeyer, Heiner; Kremsner, Peter G.; Bock, C.-Thomas

2013-01-01

Background Hepatitis D virus (HDV) infection is considered to cause more severe hepatitis than hepatitis B virus (HBV) monoinfection. With more than 9.5 million HBV-infected people, Vietnam will face an enormous health burden. The prevalence of HDV in Vietnamese HBsAg-positive patients is speculative. Therefore, we assessed the prevalence of HDV in Vietnamese patients, determined the HDV-genotype distribution and compared the findings with the clinical outcome. Methods 266 sera of well-characterized HBsAg-positive patients in Northern Vietnam were analysed for the presence of HDV using newly developed HDV-specific RT-PCRs. Sequencing and phylogenetic analysis were performed for HDV-genotyping. Results The HDV-genome prevalence observed in the Vietnamese HBsAg-positive patients was high with 15.4% while patients with acute hepatitis showed 43.3%. Phylogenetic analysis demonstrated a predominance of HDV-genotype 1 clustering in an Asian clade while HDV-genotype 2 could be also detected. The serum aminotransferase levels (AST, ALT) as well as total and direct bilirubin were significantly elevated in HDV-positive individuals (p<0.05). HDV loads were mainly low (<300 to 4.108 HDV-copies/ml). Of note, higher HDV loads were mainly found in HBV-genotype mix samples in contrast to single HBV-infections. In HBV/HDV-coinfections, HBV loads were significantly higher in HBV-genotype C in comparison to HBV-genotype A samples (p<0.05). Conclusion HDV prevalence is high in Vietnamese individuals, especially in patients with acute hepatitis B. HDV replication activity showed a HBV-genotype dependency and could be associated with elevated liver parameters. Besides serological assays molecular tests are recommended for diagnosis of HDV. Finally, the high prevalence of HBV and HDV prompts the urgent need for HBV-vaccination coverage. PMID:24205106

Physical Characteristics Of Female Basketball Players According To Playing Position

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Kucsa Richard

2015-05-01

Full Text Available Physical characteristics play an important role in the selection of young basketball players and the progress in their playing performance. The aim of the study was to analyze differences in chosen physical characteristics of Slovak U17 female basketball players with respect to their playing positions. We assumed, that there will be statistically significant differences between playing positions in each performance tests results. Chosen characteristics were analyzed for 14 players (mean/SD, age 16.34±0.82; body height 179.72±8.04 cm; body weight 67.62±7.10 kg; body fat 16.59±2.04 %; VO2max 46.20±4.71 ml.kg−1.min−1 according to their playing positions (guard, forward, center. Five specific performance tests for each player were conducted as a 3/4 Basketball court sprint, 10 × 5m Shuttle test, Lane agility drill, No-step vertical jump and Maximum vertical jump. The differences in tests results by playing positions were evaluated by one-way ANOVA. There were no significant differences found in results of chosen performance tests between playing positions (p>.05. In spite of fact, that there were no significant differences, we found interesting results between playing positions in physical characteristics. Guards had better results in speed (3.73±0.16 s, quickness (17.43±0.56 s and both lower-body power tests (47.16±3.06 cm; 57.00±3.40 cm than forwards and centers. Forwards had the best results in agility test (12.54±0.43 s. The results of this study produce useful information about physical characteristics of young basketball players according to their playing position and help to diagnose and improve their performance.

Statistics: a Bayesian perspective

National Research Council Canada - National Science Library

Berry, Donald A

1996-01-01

...: it is the only introductory textbook based on Bayesian ideas, it combines concepts and methods, it presents statistics as a means of integrating data into the significant process, it develops ideas...

Statistical Analysis and Evaluation of the Depth of the Ruts on Lithuanian State Significance Roads

Directory of Open Access Journals (Sweden)

Erinijus Getautis

2011-04-01

Full Text Available The aim of this work is to gather information about the national flexible pavement roads ruts depth, to determine its statistical dispersijon index and to determine their validity for needed requirements. Analysis of scientific works of ruts apearance in the asphalt and their influence for driving is presented in this work. Dynamical models of ruts in asphalt are presented in the work as well. Experimental outcome data of rut depth dispersijon in the national highway of Lithuania Vilnius – Kaunas is prepared. Conclusions are formulated and presented. Article in Lithuanian

Effects of fixed functional therapy on tongue and hyoid positions and posterior airway.

Science.gov (United States)

Ozdemir, Fulya; Ulkur, Feyza; Nalbantgil, Didem

2014-03-01

To evaluate how therapy with a fixed functional appliance affects airway dimensions, dentoalveolar changes, and tongue and hyoid positions. A retrospective study was carried out on 46 pre- and posttreatment lateral cephalometric radiographs of 23 post-peak Class II patients (12 girls, 11 boys) treated with a Forsus Fatigue Resistant Device (FRD) appliance. The radiographies were taken at the start and at the end of Forsus FRD appliance therapy when a Class I or overcorrected Class I canine and molar relationship was achieved. The process took an average of 5 months 13 days ± 1 month 4 days. Skeletal and dental parameters were measured using Dolphin software, and the sagittal airway area was measured by AutoCAD software. Analyses of the pre- and posttreatment means revealed that there was no statistically significant skeletal correction of the sagittal malocclusion; increase of lower incisor inclination, decrease of upper incisor inclination, decrease of interincisal angle, and rotation of occlusal plane all contributed to the reduction of overjet. The tongue area and intermaxillary space area increased in response to these dentoalveolar changes; however, there was no statistically significant change in the hyoid position or the oropharyngeal area between the two time points. The dentoalveolar changes produced by Forsus FRD appliance did not cause any significant posterior airway changes in young adult patients.

[Characteristic and clinical significance of DNA methyltransferase 3B overexpression in endometrial carcinoma].

Science.gov (United States)

Dong, Y; Zhou, M; Ba, X J; Si, J W; Li, W T; Wang, Y; Li, D; Li, T

2016-10-18

To determine the clinicopathological significance of the DNA methyltransferase 3B (DNMT3B) overexpression in endometrial carcinomas and to evaluate its correlation with hormone receptor status. Immunohistochemistry was performed to assess the expression of DNMT3B and hormone receptors in 104 endometrial carcinomas. DNMT3B overexpression occurred frequently in endometrioid carcinoma (EC, 54.8%) more than in nonendometrioid carcinoma (NEC, 30.0%) with statistical significance (P=0.028). Furthermore, there was a trend that EC with worse clinico-pathological variables and shorter survival had a higher DNMT3B expression, and the correlation between DNMT3B and tumor grade reached statistical significance (P=0.019).A negative correlation between DNMT3B and estrogen receptor (ER) or progesterone receptor (PR) expression was found in EC. NMT3B overexpression occurred frequently in the ER or PR negative subgroups (78.9%, 86.7%) more than in the positive subgroups (47.7%, 47.8%) with statistical significance (P=0.016, P=0.006). In addition, the DNMT3B overexpression increased in tumors with both ER and PR negative expression (92.9%, P=0.002). However, no such correlation was found in NEC (P>0.05). Sequence analyses demonstrated multiple ER and PR binding sites in the promoter regions of DNMT3B gene. This study showed that the expression of DNMT3B in EC and NEC was different. DNMT3B overexpression in EC was associated with the worse clinicopathological variables and might have predictive value. The methylation status of EC and NEC maybe different. In addition, in EC, DNMT3B overexpression negatively correlated with ER or PR expression. In NEC, the correlation between DNMT3B and ER or PR status was not present.

Evaluation of undergraduate nursing students' attitudes towards statistics courses, before and after a course in applied statistics.

Science.gov (United States)

Hagen, Brad; Awosoga, Olu; Kellett, Peter; Dei, Samuel Ofori

2013-09-01

Undergraduate nursing students must often take a course in statistics, yet there is scant research to inform teaching pedagogy. The objectives of this study were to assess nursing students' overall attitudes towards statistics courses - including (among other things) overall fear and anxiety, preferred learning and teaching styles, and the perceived utility and benefit of taking a statistics course - before and after taking a mandatory course in applied statistics. The authors used a pre-experimental research design (a one-group pre-test/post-test research design), by administering a survey to nursing students at the beginning and end of the course. The study was conducted at a University in Western Canada that offers an undergraduate Bachelor of Nursing degree. Participants included 104 nursing students, in the third year of a four-year nursing program, taking a course in statistics. Although students only reported moderate anxiety towards statistics, student anxiety about statistics had dropped by approximately 40% by the end of the course. Students also reported a considerable and positive change in their attitudes towards learning in groups by the end of the course, a potential reflection of the team-based learning that was used. Students identified preferred learning and teaching approaches, including the use of real-life examples, visual teaching aids, clear explanations, timely feedback, and a well-paced course. Students also identified preferred instructor characteristics, such as patience, approachability, in-depth knowledge of statistics, and a sense of humor. Unfortunately, students only indicated moderate agreement with the idea that statistics would be useful and relevant to their careers, even by the end of the course. Our findings validate anecdotal reports on statistics teaching pedagogy, although more research is clearly needed, particularly on how to increase students' perceptions of the benefit and utility of statistics courses for their nursing

Significance of upper airway influence among patients of vocal cord dysfunction for its diagnosis: Role of impulse oscillometry

Directory of Open Access Journals (Sweden)

Hira H

2009-01-01

Full Text Available Background: To identify the patients of bronchial asthma (suspected or proven, not responding to optimal therapy, for the presence of vocal cord dysfunction (VCD and to compare the diagnostic ability of flow volume (FV loop and impulse oscillometry (IOS. Materials and Methods: Fifty one patients of suspected/proven bronchial asthma not responding to optimal therapy were included for the study. Each patient was subjected to both FV loop and IOS studies. Direct visualization of the vocal cords with flexible fiberoptic bronchoscope for the presence of inspiratory vocal cord adduction during quiet respiration, with speech, and while performing provocative maneuvers was carried out. All patients were subjected to simple pulmonary function tests and recording of FV loop. IOS was performed on each patient to look for the site of obstruction and upper airway influence. The observations of both FV loop and IO studies were compared. Results: Among 51 patients participated, 12 (23.53% had bronchoscopical evidence of VCD and were labeled as VCD-positive group and rest 39 were designated VCD negative. No statistically significant difference in pulmonary function test (prereversibility results between the VCD-positive and VCD-negative patients was found. Reversible airway obstruction was observed in 75% of the patients of VCD-positive group and 67.65% of the patients in the VCD-negative group. Only one patient in the VCD-positive and none in VCD-negative group had inspiratory limb flattening of FV loop. Upper airway influence was evident by IOS in 58.3% of patients in the VCD-positive group and in 15.4% of patients in the VCD-negative group. This difference was statistically significant (P < 0.005. Conclusion: VCD was a common finding in patients with symptoms suggestive of asthma and frequently coexists with asthma. IOS was found to be a useful screening test for VCD and was more sensitive than FV loop.

The acute effects of body position strategies and respiratory therapy in paralyzed patients with acute lung injury.

Science.gov (United States)

Davis, K; Johannigman, J A; Campbell, R S; Marraccini, A; Luchette, F A; Frame, S B; Branson, R D

2001-01-01

Routine turning of critically ill patients is a standard of care. In recent years, specialized beds that provide automated turning have been introduced. These beds have been reported to improve lung function, reduce hospital-acquired pneumonia, and facilitate secretion removal. This trial was designed to measure the physiological effects of routine turning and respiratory therapy in comparison with continuous lateral rotation (CLR). The study was a prospective, quasi-experimental, random assignment, trial with patients serving as their own controls. Paralyzed, sedated patients with acute respiratory distress syndrome were eligible for study. Patients were randomized to receive four turning and secretion management regimens in random sequence for 6 h each over a period of 24 h: (1) routine turning every 2 h from the left to right lateral position; (2) routine turning every 2 h from the left to right lateral position including a 15-min period of manual percussion and postural drainage (P&PD); (3) CLR with a specialized bed that turned patients from left to right lateral position, pausing at each position for 2 min; and (4) CLR with a specialized bed that turned patients from left to right lateral position pausing at each position for 2 min, and a 15-min period of percussion provided by the pneumatic cushions of the bed every 2 h. Nineteen patients were entered into the study. There were no statistically significant differences in the measured cardiorespiratory variables. There was a tendency for the ratio of partial pressure of arterial oxygen to fractional inspired oxygen concentration (PaO2/FIO2) to increase (174 +/- 31 versus 188 +/- 36; P = 0.068) and for the ratio of deadspace to tidal volume (Vd/Vt) to decrease (0.62 +/- 0.18 versus 0.59 +/- 0.18; P = 0.19) during periods of CLR, but these differences did not achieve statistical significance. There were statistically significant increases in sputum volume during the periods of CLR. The addition of P&PD did not

Significance of isolated hepatitis B core antibody in blood donors from São Paulo

Directory of Open Access Journals (Sweden)

ALMEIDA NETO Cesar de

2001-01-01

Full Text Available The clinical significance of isolated anti-HBc is still a challenge. To elucidate the real importance of this finding in our blood donors, an investigation algorithm was tested. One hundred and twelve isolated anti-HBc seropositive blood donors underwent clinical evaluation and retesting of HBV markers. Those who presented repeatedly reactive isolated anti-HBc, received a single dose of hepatitis B recombinant vaccine to verify anti-HBs early response. A HBV-DNA determination by PCR was done for those who did not test positive to anti-HBs after vaccine. The level of anti-HBc was recorded as a ratio of the sample-to-cut-off values (S:C ratio in 57 candidates at donation. Comparing true and false-positive anti-HBc results, the different S:C ratios of them were statistically significant and when less than 2, implying in a false-positive result probability over 80%. A high percent of false-positive results (16.07% was verified after anti-HBc retesting. HBV immunity was characterized in 49.11%, either by anti-HBs detection in retesting (15.18%, or after a single dose HBV vaccination (33.93%. HBV-DNA was negative in all tested donors. In conclusion, this algorithm was useful to clarify the meaning of isolated anti-HBc in most of our blood donors.

Understanding Statistics - Cancer Statistics

Science.gov (United States)

Annual reports of U.S. cancer statistics including new cases, deaths, trends, survival, prevalence, lifetime risk, and progress toward Healthy People targets, plus statistical summaries for a number of common cancer types.

Funding source and primary outcome changes in clinical trials registered on ClinicalTrials.gov are associated with the reporting of a statistically significant primary outcome: a cross-sectional study [v2; ref status: indexed, http://f1000r.es/5bj

Directory of Open Access Journals (Sweden)

Sreeram V Ramagopalan

2015-04-01

Full Text Available Background: We and others have shown a significant proportion of interventional trials registered on ClinicalTrials.gov have their primary outcomes altered after the listed study start and completion dates. The objectives of this study were to investigate whether changes made to primary outcomes are associated with the likelihood of reporting a statistically significant primary outcome on ClinicalTrials.gov. Methods: A cross-sectional analysis of all interventional clinical trials registered on ClinicalTrials.gov as of 20 November 2014 was performed. The main outcome was any change made to the initially listed primary outcome and the time of the change in relation to the trial start and end date. Findings: 13,238 completed interventional trials were registered with ClinicalTrials.gov that also had study results posted on the website. 2555 (19.3% had one or more statistically significant primary outcomes. Statistical analysis showed that registration year, funding source and primary outcome change after trial completion were associated with reporting a statistically significant primary outcome. Conclusions: Funding source and primary outcome change after trial completion are associated with a statistically significant primary outcome report on clinicaltrials.gov.

Surveys Assessing Students' Attitudes toward Statistics: A Systematic Review of Validity and Reliability

Science.gov (United States)

Nolan, Meaghan M.; Beran, Tanya; Hecker, Kent G.

2012-01-01

Students with positive attitudes toward statistics are likely to show strong academic performance in statistics courses. Multiple surveys measuring students' attitudes toward statistics exist; however, a comparison of the validity and reliability of interpretations based on their scores is needed. A systematic review of relevant electronic…

Diffusion tensor MR imaging (DTI) metrics in the cervical spinal cord in asymptomatic HIV-positive patients

Energy Technology Data Exchange (ETDEWEB)

Mueller-Mang, Christina; Mang, Thomas; Fruehwald-Pallamar, Julia; Weber, Michael; Thurnher, Majda M. [Medical University of Vienna, Department of Radiology, Vienna (Austria); Law, Meng [University of Southern California, Los Angeles County Hospital and USC Medical Center, Department of Radiology, Keck School of Medicine, Los Angeles, CA (United States)

2011-08-15

This study was conducted to compare diffusion tensor MR imaging (DTI) metrics of the cervical spinal cord in asymptomatic human immunodeficiency virus (HIV)-positive patients with those measured in healthy volunteers, and to assess whether DTI is a valuable diagnostic tool in the early detection of HIV-associated myelopathy (HIVM). MR imaging of the cervical spinal cord was performed in 20 asymptomatic HIV-positive patients and in 20 healthy volunteers on a 3-T MR scanner. Average fractional anisotropy (FA), mean diffusivity (MD), and major (E1) and minor (E2, E3) eigenvalues were calculated within regions of interest (ROIs) at the C2/3 level (central and bilateral anterior, lateral and posterior white matter). Statistical analysis showed significant differences with regard to mean E3 values between patients and controls (p = 0.045; mixed-model analysis of variance (ANOVA) test). Mean FA was lower, and mean MD, mean E1, and mean E2 were higher in each measured ROI in patients compared to controls, but these differences were not statistically significant. Asymptomatic HIV-positive patients demonstrate only subtle changes in DTI metrics measured in the cervical spinal cord compared to healthy volunteers that currently do not support using DTI as a diagnostic tool for the early detection of HIVM. (orig.)

Statistical analysis and data management

International Nuclear Information System (INIS)

Anon.

1981-01-01

This report provides an overview of the history of the WIPP Biology Program. The recommendations of the American Institute of Biological Sciences (AIBS) for the WIPP biology program are summarized. The data sets available for statistical analyses and problems associated with these data sets are also summarized. Biological studies base maps are presented. A statistical model is presented to evaluate any correlation between climatological data and small mammal captures. No statistically significant relationship between variance in small mammal captures on Dr. Gennaro's 90m x 90m grid and precipitation records from the Duval Potash Mine were found

How immediate and significant is the outcome of training on diversified diets, hygiene and food safety? An effort to mitigate child undernutrition in rural Malawi.

Science.gov (United States)

Seetha, Anitha; Tsusaka, Takuji W; Munthali, Timalizge W; Musukwa, Maggie; Mwangwela, Agnes; Kalumikiza, Zione; Manani, Tinna; Kachulu, Lizzie; Kumwenda, Nelson; Musoke, Mike; Okori, Patrick

2018-04-01

The present study examined the impacts of training on nutrition, hygiene and food safety designed by the Nutrition Working Group, Child Survival Collaborations and Resources Group (CORE). Adapted from the 21d Positive Deviance/Hearth model, mothers were trained on the subjects of appropriate complementary feeding, water, sanitation and hygiene (WASH) practices, and aflatoxin contamination in food. To assess the impacts on child undernutrition, a randomised controlled trial was implemented on a sample of 179 mothers and their children (<2 years old) in two districts of Malawi, namely Mzimba and Balaka. Settings A 21d intensive learning-by-doing process using the positive deviance approach. Malawian children and mothers. Difference-in-difference panel regression analysis revealed that the impacts of the comprehensive training were positive and statistically significant on the Z-scores for wasting and underweight, where the effects increased constantly over time within the 21d time frame. As for stunting, the coefficients were not statistically significant during the 21d programme, although the level of significance started increasing in 2 weeks, indicating that stunting should also be alleviated in a slightly longer time horizon. The study clearly suggests that comprehensive training immediately guides mothers into improved dietary and hygiene practices, and that improved practices take immediate and progressive effects in ameliorating children's undernutrition.

Comparison of Chest X-Ray Findings of Smear Positive and Smear Negative Patients with Pulmonary Tuberculosis

International Nuclear Information System (INIS)

Ebrahimzadeh, Azadeh; Mohammadifard, Mahyar; Naseh, Godratallah

2014-01-01

Tuberculosis is a chronic pulmonary infectious disease that has affected one-third of the people in the world. It causes nine million new cases and two million deaths per year. Chest radiography associated with Ziehl-Neelsen acid-fast staining procedure significantly helps the diagnosis of pulmonary tuberculosis (PTB). Chest radiography can help the diagnosis of tuberculosis in patients with a negative smear sample result that is mainly diagnosed with delay. In this study, chest X-ray findings of PTB were compared in two groups of smear positive and smear negative patients. In this retrospective descriptive-analytical study, 376 patients who had been confirmed with PTB were referred to Birjand Health Care Center from 2001 to 2006. Out of the 376 patients, 100 patients with a positive smear based on WHO criteria were selected. In addition, among negative smear patients, 100 were selected in whom similar demographic characteristics with positive smear patients were seen. All of them had undergone chest radiographies that were then interpreted by two expert radiologists independently. Moreover, all patients’ sputa were examined by an expert laboratory technician at the reference laboratory of the health center. The obtained data were analyzed by means of frequency distribution table and descriptive statistics using SPSS (version 15) and Chi-square statistical test. Except reticulo-nodular infiltration, the relative frequency of other radiographic findings in positive smear patients were more than negative smear patients; and only differences in calcification variables, mediastinal widening, patchy infiltration and hilar adenopathy were statistically significant (P < 0.05). Based on the results of this study, although radiographic findings are not diagnostic in PTB, they are helpful if the assessment associates with the view of clinical manifestations and sputum smears

Confounding and Statistical Significance of Indirect Effects: Childhood Adversity, Education, Smoking, and Anxious and Depressive Symptomatology

Directory of Open Access Journals (Sweden)

Mashhood Ahmed Sheikh

2017-08-01

mediate the association between childhood adversity and ADS in adulthood. However, when education was excluded as a mediator-response confounding variable, the indirect effect of childhood adversity on ADS in adulthood was statistically significant (p < 0.05. This study shows that a careful inclusion of potential confounding variables is important when assessing mediation.

A comparative study on scapular static position between females with and without generalized joint hyper mobility.

Science.gov (United States)

Moghadam, Afsun Nodehi; Salimee, Maryam Moghadam

2012-08-01

Generalized joint hyper mobility predisposes some individuals to a wide variety of musculoskeletal complaints. Given the critical role of scapular position in function of shoulder, the aim of this study was to compare scapular position between persons with and without general joint hyper mobility. By nonprobability sampling 30 hyper mobile persons at average of 22.86 ±2.77 years of age and 30 non hyper mobile persons (age 23.6 ± 2.73years) through a case-control design participated in the study. Scapular position was assessed according to the lateral scapular slide test. Independent t test and repeated measures ANOVA were used to statistically analyze scapular position differences between groups. Compared to non hyper mobile persons, those with General joint hyper mobility demonstrated a significantly higher superior scapula slide in dependent arm position (p = 0.03). However, no significant difference was found between another scores between two groups (p > 0.05). The results suggest that altered scapular position may be an important aspect of General joint hyper mobility.

[Big data in official statistics].

Science.gov (United States)

Zwick, Markus

2015-08-01

The concept of "big data" stands to change the face of official statistics over the coming years, having an impact on almost all aspects of data production. The tasks of future statisticians will not necessarily be to produce new data, but rather to identify and make use of existing data to adequately describe social and economic phenomena. Until big data can be used correctly in official statistics, a lot of questions need to be answered and problems solved: the quality of data, data protection, privacy, and the sustainable availability are some of the more pressing issues to be addressed. The essential skills of official statisticians will undoubtedly change, and this implies a number of challenges to be faced by statistical education systems, in universities, and inside the statistical offices. The national statistical offices of the European Union have concluded a concrete strategy for exploring the possibilities of big data for official statistics, by means of the Big Data Roadmap and Action Plan 1.0. This is an important first step and will have a significant influence on implementing the concept of big data inside the statistical offices of Germany.

The efficacy of adult christian support groups in coping with the death of a significant loved one.

Science.gov (United States)

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.

Isometric elbow extensors strength in supine- and prone-lying positions.

Science.gov (United States)

Abdelzaher, Ibrahim E; Ababneh, Anas F; Alzyoud, Jehad M

2013-01-01

The purpose of this study was to compare isometric strength of elbow extensors measured in supine- and prone-lying positions at elbow flexion angles of 45 and 90 degrees. Twenty-two male subjects under single-blind procedures participated in the study. Each subject participated in both supine-lying and prone-lying measuring protocols. Calibrated cable tensiometer was used to measure isometric strength of the right elbow extensors and a biofeedback electromyography was used to assure no substitution movements from shoulder girdle muscles. The mean values of isometric strength of elbow extensors measured from supine-lying position at elbow flexion angles of 45 and 90 degrees were 11.1  ±  4.2 kg and 13.1  ±  4.6 kg, while those measured from prone-lying position were 9.9  ±  3.6 kg and 12  ±  4.2 kg, respectively. There is statistical significant difference between the isometric strength of elbow extensors measured from supine-lying position at elbow flexion angles of 45 and 90 degrees compared to that measured from prone-lying position (p  isometric strength of elbow extensors since supine-lying starting position is better than prone-lying starting position.

Oral Health Status of Institutionalized Older Women from Different Socioeconomic Positions.

Science.gov (United States)

Heredia-Ponce, Erika; Irigoyen-Camacho, A Esther; Sánchez-García, Sergio

2017-01-01

To determine the association between oral health and socioeconomic position in institutionalized older women in Mexico City. A cross-sectional study was performed in two groups: high socioeconomic position (HSEP), living in a private retirement home, and low socioeconomic position (LSEP), living in a public assistance center. Oral health was determined by edentulism, oral hygiene, healthy teeth, experience of dental caries, missing and filled teeth, gingival bleeding, dental calculus, and periodontal disease. A latent class analysis (LCA) was used to classify oral health status in dentate. Included were 170 women (HSEP 54.1% and LSEP 45.8%), average age 77.3 (SD = 9.3) years. Oral health status was formed: Edentulous 32.4% HSEP and 67.6% LSEP; Class 1 Unfavorable 0% HSEP and 100% LSEP; Class2 Slightly favorable 41.2% HSEP and58.8% LSEP; and Class3 Favorable 84.6% HSEP and 15.4% LSEP. There was a statistically significant association between socioeconomic position (p < .001) and oral health status. The oral health of women studied was not optimal. Higher socioeconomic position was associated with better oral health status.

Statistical phenomena - experiments results. II

International Nuclear Information System (INIS)

Schnell, W.

1977-01-01

The stochastic cooling of proton and antiproton beams is discussed. Stochastic cooling is the gradual reduction of emittance of a coasting beam by a feedback system, sensing and correcting the statistical fluctuations of the beam's position or momentum. The correction at every turn can be partial or complete. Transverse and longitudinal emittance of the beam are considered and the systems designed to cool the beams are described. (B.D.)

Explicit and implicit positive alcohol expectancies in problem and non-problem drinkers: differences across age groups from young adolescence to adulthood

Directory of Open Access Journals (Sweden)

Aurélie eVilenne

2015-11-01

Full Text Available Aims: Recent studies with animal models showed that the stimulant and sedative effects of alcohol change during the adolescent period. In humans, the stimulant effects of ethanol are most often indirectly recorded through the measurement of explicit and implicit alcohol effect expectancies. However, it is unknown how such implicit and explicit expectancies evolve with age in humans during adolescence.Methods: Adolescent (13-16 year old, young adult (17-18 year old and adult (35-55 year old participants were recruited. On the basis of their score on the Alcohol Use Disorder Identification Test (AUDIT, they were classified as non-problem (AUDIT ≤ 7 or problem (AUDIT ≥ 11 drinkers. The participants completed the Alcohol Expectancy Questionnaire (AEQ and performed two unipolar Implicit Association Test (IAT to assess implicit associations between alcohol and the concepts of stimulation and sedation.Results: Problem drinkers from the three age groups reported significantly higher positive alcohol expectancies than non-problem drinkers on all AEQ subscales. Positive alcohol explicit expectancies also gradually decreased with age, with adolescent problem drinkers reporting especially high positive expectancies. This effect was statistically significant for all positive expectancies, with the exception of relaxation expectancies that were only close to statistical significance. In contrast, stimulation and sedation alcohol implicit associations were not significantly different between problem and non-problem drinkers and did not change with age.Conclusions: These results indicate that explicit positive alcohol effect expectancies predict current alcohol consumption levels, especially in adolescents. Positive alcohol expectancies also gradually decrease with age in the three cross-sectional groups of adolescents, young adults and adults. This effect might be related to changes in the physiological response to alcohol.

Spectral statistics of chaotic many-body systems

International Nuclear Information System (INIS)

Dubertrand, Rémy; Müller, Sebastian

2016-01-01

We derive a trace formula that expresses the level density of chaotic many-body systems as a smooth term plus a sum over contributions associated to solutions of the nonlinear Schrödinger (or Gross–Pitaevski) equation. Our formula applies to bosonic systems with discretised positions, such as the Bose–Hubbard model, in the semiclassical limit as well as in the limit where the number of particles is taken to infinity. We use the trace formula to investigate the spectral statistics of these systems, by studying interference between solutions of the nonlinear Schrödinger equation. We show that in the limits taken the statistics of fully chaotic many-particle systems becomes universal and agrees with predictions from the Wigner–Dyson ensembles of random matrix theory. The conditions for Wigner–Dyson statistics involve a gap in the spectrum of the Frobenius–Perron operator, leaving the possibility of different statistics for systems with weaker chaotic properties. (paper)

Tyrosine hydroxylase positive nerves and mast cells in the porcine gallbladder

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I. Stefanov

2017-03-01

Full Text Available The aim of this study was to detect the localisation of tyrosine hydroxylase (TH positive nerve fibres (THN and distribution of tyrosine hydroxylase positive mast cells (THMC in the wall of porcine gallbladder. THN were observed as single fibres, nerve fibres forming perivascular plexuses and nerve fibres grouped within the nerve fascicles. In the gallbladder`s fundus, body and neck, the TH+ fibres formed mucosal, muscular and serosal nonganglionated nerve plexuses. Toluidine blue (TB staining was used to confirm that the TH positive cells were mast cells. The number of THMC in the propria of gallbladder`s fundus, body and neck was significantly higher than in the muscular and serosal layers in both genders. The number of mast cells in the musculature was higher than in the serosa. The density and location of the THMC were similar to the TB positive (with gamma meta-chromasia mast cells in both males and females, and statistically significant difference was not established. In conclusion, original data concerning the existence and localisation of catecholaminergic nerves and THMC distribution in the porcine gallbladder’s wall are presented. The results could con-tribute to the body of knowledge of functional communication between autonomic nerves and mast cells in the gallbladder.

Probabilistic anatomical labeling of brain structures using statistical probabilistic anatomical maps

International Nuclear Information System (INIS)

Kim, Jin Su; Lee, Dong Soo; Lee, Byung Il; Lee, Jae Sung; Shin, Hee Won; Chung, June Key; Lee, Myung Chul

2002-01-01

The use of statistical parametric mapping (SPM) program has increased for the analysis of brain PET and SPECT images. Montreal neurological institute (MNI) coordinate is used in SPM program as a standard anatomical framework. While the most researchers look up Talairach atlas to report the localization of the activations detected in SPM program, there is significant disparity between MNI templates and Talairach atlas. That disparity between Talairach and MNI coordinates makes the interpretation of SPM result time consuming, subjective and inaccurate. The purpose of this study was to develop a program to provide objective anatomical information of each x-y-z position in ICBM coordinate. Program was designed to provide the anatomical information for the given x-y-z position in MNI coordinate based on the statistical probabilistic anatomical map (SPAM) images of ICBM. When x-y-z position was given to the program, names of the anatomical structures with non-zero probability and the probabilities that the given position belongs to the structures were tabulated. The program was coded using IDL and JAVA language for the easy transplantation to any operating system or platform. Utility of this program was shown by comparing the results of this program to those of SPM program. Preliminary validation study was performed by applying this program to the analysis of PET brain activation study of human memory in which the anatomical information on the activated areas are previously known. Real time retrieval of probabilistic information with 1 mm spatial resolution was archived using the programs. Validation study showed the relevance of this program: probability that the activated area for memory belonged to hippocampal formation was more than 80%. These programs will be useful for the result interpretation of the image analysis performed on MNI coordinate, as done in SPM program

Comparison of beam position calculation methods for application in digital acquisition systems

Science.gov (United States)

Reiter, A.; Singh, R.

2018-05-01

Different approaches to the data analysis of beam position monitors in hadron accelerators are compared adopting the perspective of an analog-to-digital converter in a sampling acquisition system. Special emphasis is given to position uncertainty and robustness against bias and interference that may be encountered in an accelerator environment. In a time-domain analysis of data in the presence of statistical noise, the position calculation based on the difference-over-sum method with algorithms like signal integral or power can be interpreted as a least-squares analysis of a corresponding fit function. This link to the least-squares method is exploited in the evaluation of analysis properties and in the calculation of position uncertainty. In an analytical model and experimental evaluations the positions derived from a straight line fit or equivalently the standard deviation are found to be the most robust and to offer the least variance. The measured position uncertainty is consistent with the model prediction in our experiment, and the results of tune measurements improve significantly.

Positive smoking outcome expectancies mediate the association between negative affect and smoking urge among women during a quit attempt.

Science.gov (United States)

Cano, Miguel Ángel; Lam, Cho Y; Chen, Minxing; Adams, Claire E; Correa-Fernández, Virmarie; Stewart, Diana W; McClure, Jennifer B; Cinciripini, Paul M; Wetter, David W

2014-08-01

Ecological momentary assessment was used to examine associations between negative affect, positive smoking outcome expectancies, and smoking urge during the first 7 days of a smoking quit attempt. Participants were 302 female smokers who enrolled in an individually tailored smoking cessation treatment study. Multilevel mediation analysis was used to examine the temporal relationship among the following: (a) the effects of negative affect and positive smoking outcome expectancies at 1 assessment point (e.g., time j) on smoking urge at the subsequent time point (e.g., time j + 1) in Model 1; and, (b) the effects of negative affect and smoking urge at time j on positive smoking outcome expectancies at time j + 1 in Model 2. The results from Model 1 showed a statistically significant effect of negative affect at time j on smoking urge at time j + 1, and this effect was mediated by positive smoking outcome expectancies at time j, both within- and between-participants. In Model 2, the within-participant indirect effect of negative affect at time j on positive smoking outcome expectancies at time j + 1 through smoking urge at time j was nonsignificant. However, a statistically significant indirect between-participants effect was found in Model 2. The findings support the hypothesis that urge and positive smoking outcome expectancies increase as a function of negative affect, and suggest a stronger effect of expectancies on urge as opposed to the effect of urge on expectancies.

National Statistical Commission and Indian Official Statistics*

Indian Academy of Sciences (India)

IAS Admin

a good collection of official statistics of that time. With more .... statistical agencies and institutions to provide details of statistical activities .... ing several training programmes. .... ful completion of Indian Statistical Service examinations, the.

Position-momentum uncertainty relations in the presence of quantum memory

Energy Technology Data Exchange (ETDEWEB)

Furrer, Fabian, E-mail: furrer@eve.phys.s.u-tokyo.ac.jp [Department of Physics, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Berta, Mario [Institute for Quantum Information and Matter, Caltech, Pasadena, California 91125 (United States); Institute for Theoretical Physics, ETH Zurich, Wolfgang-Pauli-Str. 27, 8093 Zürich (Switzerland); Tomamichel, Marco [School of Physics, The University of Sydney, Sydney 2006 (Australia); Centre for Quantum Technologies, National University of Singapore, Singapore 117543 (Singapore); Scholz, Volkher B. [Institute for Theoretical Physics, ETH Zurich, Wolfgang-Pauli-Str. 27, 8093 Zürich (Switzerland); Christandl, Matthias [Institute for Theoretical Physics, ETH Zurich, Wolfgang-Pauli-Str. 27, 8093 Zürich (Switzerland); Department of Mathematical Sciences, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen (Denmark)

2014-12-15

A prominent formulation of the uncertainty principle identifies the fundamental quantum feature that no particle may be prepared with certain outcomes for both position and momentum measurements. Often the statistical uncertainties are thereby measured in terms of entropies providing a clear operational interpretation in information theory and cryptography. Recently, entropic uncertainty relations have been used to show that the uncertainty can be reduced in the presence of entanglement and to prove security of quantum cryptographic tasks. However, much of this recent progress has been focused on observables with only a finite number of outcomes not including Heisenberg’s original setting of position and momentum observables. Here, we show entropic uncertainty relations for general observables with discrete but infinite or continuous spectrum that take into account the power of an entangled observer. As an illustration, we evaluate the uncertainty relations for position and momentum measurements, which is operationally significant in that it implies security of a quantum key distribution scheme based on homodyne detection of squeezed Gaussian states.

Official Statistics and Statistics Education: Bridging the Gap

Directory of Open Access Journals (Sweden)

Gal Iddo

2017-03-01

Full Text Available This article aims to challenge official statistics providers and statistics educators to ponder on how to help non-specialist adult users of statistics develop those aspects of statistical literacy that pertain to official statistics. We first document the gap in the literature in terms of the conceptual basis and educational materials needed for such an undertaking. We then review skills and competencies that may help adults to make sense of statistical information in areas of importance to society. Based on this review, we identify six elements related to official statistics about which non-specialist adult users should possess knowledge in order to be considered literate in official statistics: (1 the system of official statistics and its work principles; (2 the nature of statistics about society; (3 indicators; (4 statistical techniques and big ideas; (5 research methods and data sources; and (6 awareness and skills for citizens’ access to statistical reports. Based on this ad hoc typology, we discuss directions that official statistics providers, in cooperation with statistics educators, could take in order to (1 advance the conceptualization of skills needed to understand official statistics, and (2 expand educational activities and services, specifically by developing a collaborative digital textbook and a modular online course, to improve public capacity for understanding of official statistics.

Subjective visual vertical after treatment of benign paroxysmal positional vertigo

Directory of Open Access Journals (Sweden)

Maristela Mian Ferreira

Full Text Available Abstract Introduction: Otolith function can be studied by testing the subjective visual vertical, because the tilt of the vertical line beyond the normal range is a sign of vestibular dysfunction. Benign paroxysmal positional vertigo is a disorder of one or more labyrinthine semicircular canals caused by fractions of otoliths derived from the utricular macula. Objective: To compare the subjective visual vertical with the bucket test before and immediately after the particle repositioning maneuver in patients with benign paroxysmal positional vertigo. Methods: We evaluated 20 patients. The estimated position where a fluorescent line within a bucket reached the vertical position was measured before and immediately after the particle repositioning maneuver. Data were tabulated and statistically analyzed. Results: Before repositioning maneuver, 9 patients (45.0% had absolute values of the subjective visual vertical above the reference standard and 2 (10.0% after the maneuver; the mean of the absolute values of the vertical deviation was significantly lower after the intervention (p < 0.001. Conclusion: There is a reduction of the deviations of the subjective visual vertical, evaluated by the bucket test, immediately after the particle repositioning maneuver in patients with benign paroxysmal positional vertigo.

The influence of positive vs. negative affect on multitasking.

Science.gov (United States)

Morgan, Brent; D'Mello, Sidney K

2016-10-01

Considerable research has investigated how affect influences performance on a single task; however, little is known about the role of affect in complex multitasking environments. In this paper, 178 participants multitasked in a synthetic work environment (SYNWORK) consisting of memory, visual monitoring, auditory monitoring, and math tasks. Participants multitasked for a 3-min baseline phase (MT1), following which they were randomly assigned to watch one of three affect-induction videos: positive, neutral, or negative. Participants then resumed multitasking for two additional critical phases (MT2, MT3; 3min each). In MT2, performance of the positive and neutral conditions was statistically equivalent and higher than the negative condition. In MT3, the positive condition performed better than the negative condition, with the neutral condition not significantly different from the other two. The differences in overall multitasking scores were largely driven by errors in the Math task (the most cognitively demanding task) in MT2 and the Memory task in MT3. These findings have implications for how positive and negative affective states influence processing in a cognitively demanding multitasking environment. Copyright © 2016 Elsevier B.V. All rights reserved.

Ontologies and tag-statistics

Science.gov (United States)

Tibély, Gergely; Pollner, Péter; Vicsek, Tamás; Palla, Gergely

2012-05-01

Due to the increasing popularity of collaborative tagging systems, the research on tagged networks, hypergraphs, ontologies, folksonomies and other related concepts is becoming an important interdisciplinary area with great potential and relevance for practical applications. In most collaborative tagging systems the tagging by the users is completely ‘flat’, while in some cases they are allowed to define a shallow hierarchy for their own tags. However, usually no overall hierarchical organization of the tags is given, and one of the interesting challenges of this area is to provide an algorithm generating the ontology of the tags from the available data. In contrast, there are also other types of tagged networks available for research, where the tags are already organized into a directed acyclic graph (DAG), encapsulating the ‘is a sub-category of’ type of hierarchy between each other. In this paper, we study how this DAG affects the statistical distribution of tags on the nodes marked by the tags in various real networks. The motivation for this research was the fact that understanding the tagging based on a known hierarchy can help in revealing the hidden hierarchy of tags in collaborative tagging systems. We analyse the relation between the tag-frequency and the position of the tag in the DAG in two large sub-networks of the English Wikipedia and a protein-protein interaction network. We also study the tag co-occurrence statistics by introducing a two-dimensional (2D) tag-distance distribution preserving both the difference in the levels and the absolute distance in the DAG for the co-occurring pairs of tags. Our most interesting finding is that the local relevance of tags in the DAG (i.e. their rank or significance as characterized by, e.g., the length of the branches starting from them) is much more important than their global distance from the root. Furthermore, we also introduce a simple tagging model based on random walks on the DAG, capable of

Ontologies and tag-statistics

International Nuclear Information System (INIS)

Tibély, Gergely; Vicsek, Tamás; Pollner, Péter; Palla, Gergely

2012-01-01

Due to the increasing popularity of collaborative tagging systems, the research on tagged networks, hypergraphs, ontologies, folksonomies and other related concepts is becoming an important interdisciplinary area with great potential and relevance for practical applications. In most collaborative tagging systems the tagging by the users is completely ‘flat’, while in some cases they are allowed to define a shallow hierarchy for their own tags. However, usually no overall hierarchical organization of the tags is given, and one of the interesting challenges of this area is to provide an algorithm generating the ontology of the tags from the available data. In contrast, there are also other types of tagged networks available for research, where the tags are already organized into a directed acyclic graph (DAG), encapsulating the ‘is a sub-category of’ type of hierarchy between each other. In this paper, we study how this DAG affects the statistical distribution of tags on the nodes marked by the tags in various real networks. The motivation for this research was the fact that understanding the tagging based on a known hierarchy can help in revealing the hidden hierarchy of tags in collaborative tagging systems. We analyse the relation between the tag-frequency and the position of the tag in the DAG in two large sub-networks of the English Wikipedia and a protein-protein interaction network. We also study the tag co-occurrence statistics by introducing a two-dimensional (2D) tag-distance distribution preserving both the difference in the levels and the absolute distance in the DAG for the co-occurring pairs of tags. Our most interesting finding is that the local relevance of tags in the DAG (i.e. their rank or significance as characterized by, e.g., the length of the branches starting from them) is much more important than their global distance from the root. Furthermore, we also introduce a simple tagging model based on random walks on the DAG, capable of

Recursive integral equations with positive kernel for lattice calculations

International Nuclear Information System (INIS)

Illuminati, F.; Isopi, M.

1990-11-01

A Kirkwood-Salzburg integral equation, with positive defined kernel, for the states of lattice models of statistical mechanics and quantum field theory is derived. The equation is defined in the thermodynamic limit, and its iterative solution is convergent. Moreover, positivity leads to an exact a priori bound on the iteration. The equation's relevance as a reliable algorithm for lattice calculations is therefore suggested, and it is illustrated with a simple application. It should provide a viable alternative to Monte Carlo methods for models of statistical mechanics and lattice gauge theories. 10 refs

Two Methods for Turning and Positioning and the Effect on Pressure Ulcer Development: A Comparison Cohort Study.

Science.gov (United States)

Powers, Jan

2016-01-01

We evaluated 2 methods for patient positioning on the development of pressure ulcers; specifically, standard of care (SOC) using pillows versus a patient positioning system (PPS). The study also compared turning effectiveness as well as nursing resources related to patient positioning and nursing injuries. A nonrandomized comparison design was used for the study. Sixty patients from a trauma/neurointensive care unit were included in the study. Patients were randomly assigned to 1 of 2 teams per standard bed placement practices at the institution. Patients were identified for enrollment in the study if they were immobile and mechanically ventilated with anticipation of 3 days or more on mechanical ventilation. Patients were excluded if they had a preexisting pressure ulcer. Patients were evaluated daily for the presence of pressure ulcers. Data were collected on the number of personnel required to turn patients. Once completed, the angle of the turn was measured. The occupational health database was reviewed to determine nurse injuries. The final sample size was 59 (SOC = 29; PPS = 30); there were no statistical differences between groups for age (P = .10), body mass index (P = .65), gender (P = .43), Braden Scale score (P = .46), or mobility score (P = .10). There was a statistically significant difference in the number of hospital-acquired pressure ulcers between turning methods (6 in the SOC group vs 1 in the PPS group; P = .042). The number of nurses needed for the SOC method was significantly higher than the PPS (P ≤ 0.001). The average turn angle achieved using the PPS was 31.03°, while the average turn angle achieved using SOC was 22.39°. The difference in turn angle from initial turn to 1 hour after turning in the SOC group was statistically significant (P patients to prevent development of pressure ulcers.

When it hurts, a positive attitude may help: association of positive affect with daily walking in knee osteoarthritis. Results from a multicenter longitudinal cohort study.

Science.gov (United States)

White, Daniel K; Keysor, Julie J; Neogi, Tuhina; Felson, David T; LaValley, Michael; Gross, K Doug; Niu, Jingbo; Nevitt, Michael; Lewis, Cora E; Torner, Jim; Fredman, Lisa

2012-09-01

While depressive symptoms and knee pain are independently known to impede daily walking in older adults, it is unknown whether positive affect promotes daily walking. This study investigated this association among adults with knee osteoarthritis (OA) and examined whether knee pain modified this association. This study is a cross-sectional analysis of the Multicenter Osteoarthritis Study. We included 1,018 participants (mean ± SD age 63.1 ± 7.8 years, 60% women) who had radiographic knee OA and had worn a StepWatch monitor to record their number of steps per day. High and low positive affect and depressive symptoms were based on the Center for Epidemiologic Studies Depression Scale. Knee pain was categorized as present in respondents who reported pain on most days at both a clinic visit and a telephone screening. Compared to respondents with low positive affect (27% of all respondents), those with high positive affect (63%) walked a similar number of steps per day, while those with depressive symptoms (10%) walked less (adjusted β -32.6 [95% confidence interval (95% CI) -458.9, 393.8] and -579.1 [95% CI -1,274.9, 116.7], respectively). There was a statistically significant interaction of positive affect by knee pain (P = 0.0045). Among the respondents with knee pain (39%), those with high positive affect walked significantly more steps per day (adjusted β 711.0 [95% CI 55.1, 1,366.9]) than those with low positive affect. High positive affect was associated with more daily walking among adults with painful knee OA. Positive affect may be an important psychological factor to consider for promoting physical activity among people with painful knee OA. Copyright © 2012 by the American College of Rheumatology.

Statistical projection effects in a hydrodynamic pilot-wave system

Science.gov (United States)

Sáenz, Pedro J.; Cristea-Platon, Tudor; Bush, John W. M.

2018-03-01

Millimetric liquid droplets can walk across the surface of a vibrating fluid bath, self-propelled through a resonant interaction with their own guiding or `pilot' wave fields. These walking droplets, or `walkers', exhibit several features previously thought to be peculiar to the microscopic, quantum realm. In particular, walkers confined to circular corrals manifest a wave-like statistical behaviour reminiscent of that of electrons in quantum corrals. Here we demonstrate that localized topological inhomogeneities in an elliptical corral may lead to resonant projection effects in the walker's statistics similar to those reported in quantum corrals. Specifically, we show that a submerged circular well may drive the walker to excite specific eigenmodes in the bath that result in drastic changes in the particle's statistical behaviour. The well tends to attract the walker, leading to a local peak in the walker's position histogram. By placing the well at one of the foci, a mode with maxima near the foci is preferentially excited, leading to a projection effect in the walker's position histogram towards the empty focus, an effect strongly reminiscent of the quantum mirage. Finally, we demonstrate that the mean pilot-wave field has the same form as the histogram describing the walker's statistics.

Attitude towards statistics and performance among post-graduate students

Science.gov (United States)

Rosli, Mira Khalisa; Maat, Siti Mistima

2017-05-01

For student to master Statistics is a necessity, especially for those post-graduates that are involved in the research field. The purpose of this research was to identify the attitude towards Statistics among the post-graduates and to determine the relationship between the attitude towards Statistics and post-graduates' of Faculty of Education, UKM, Bangi performance. 173 post-graduate students were chosen randomly to participate in the study. These students registered in Research Methodology II course that was introduced by faculty. A survey of attitude toward Statistics using 5-points Likert scale was used for data collection purposes. The instrument consists of four components such as affective, cognitive competency, value and difficulty. The data was analyzed using the SPSS version 22 in producing the descriptive and inferential Statistics output. The result of this research showed that there is a medium and positive relation between attitude towards statistics and students' performance. As a conclusion, educators need to access students' attitude towards the course to accomplish the learning outcomes.

The effect of lateral decubitus position on nocturnal intraocular pressure over a habitual 24-hour period in healthy adults.

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Jie Hao

Full Text Available PURPOSE: To investigate the effect of lateral decubitus position (LDP on nocturnal intraocular pressure (IOP and the effect of LDP on 24-hour habitual IOP pattern in healthy subjects. METHODS: Intraocular pressure was measured every 2-hours using an Accupen Applanation Tonometer (Accutome, USA. During the diurnal period (7:30 am, 9:30 am, 11:30 am, 1:30 pm, 3:30 pm, 5:30 pm, 7:30 pm, and 9:30 pm, IOP was measured in the sitting position under bright light (500-1000 lux after the subjects had been seated for 5 min. The nocturnal IOP was measured in the supine position, right LDP, and left LDP, with randomized sequences, under dim light (<10 lux at 11:30 pm, 1:30 am, 3:30 am, and 5:30 am. The subjects were awakened and maintained each position for 5 min before the measurement. The 24-hour habitual IOP patterns were obtained according to the nocturnal position (supine, right LDP and left LDP for either eye. P<0.05 was considered to be significant. RESULTS: Nineteen healthy subjects were included with a mean age of 51.3±5.8 years. During the nocturnal period, a significant IOP difference was found between the dependent eye (the eye on the lower side of LDP and the supine position, but not for all the nocturnal time points. Over a 24-hour period, the effect of LDP on habitual IOP pattern was not statistically significant, although the mean nocturnal IOP and the diurnal-nocturnal IOP change for the right and the left eye in the LDP pattern was slightly higher than that in the sitting-supine pattern. CONCLUSION: Significant nocturnal IOP differences existed between the dependent eye and the supine, but did not occur consistently for all time points. Over a 24-hour period, the effect of LDP on habitual IOP pattern was not statistically significant in healthy subjects.

Development of free statistical software enabling researchers to calculate confidence levels, clinical significance curves and risk-benefit contours

International Nuclear Information System (INIS)

Shakespeare, T.P.; Mukherjee, R.K.; Gebski, V.J.

2003-01-01

Confidence levels, clinical significance curves, and risk-benefit contours are tools improving analysis of clinical studies and minimizing misinterpretation of published results, however no software has been available for their calculation. The objective was to develop software to help clinicians utilize these tools. Excel 2000 spreadsheets were designed using only built-in functions, without macros. The workbook was protected and encrypted so that users can modify only input cells. The workbook has 4 spreadsheets for use in studies comparing two patient groups. Sheet 1 comprises instructions and graphic examples for use. Sheet 2 allows the user to input the main study results (e.g. survival rates) into a 2-by-2 table. Confidence intervals (95%), p-value and the confidence level for Treatment A being better than Treatment B are automatically generated. An additional input cell allows the user to determine the confidence associated with a specified level of benefit. For example if the user wishes to know the confidence that Treatment A is at least 10% better than B, 10% is entered. Sheet 2 automatically displays clinical significance curves, graphically illustrating confidence levels for all possible benefits of one treatment over the other. Sheet 3 allows input of toxicity data, and calculates the confidence that one treatment is more toxic than the other. It also determines the confidence that the relative toxicity of the most effective arm does not exceed user-defined tolerability. Sheet 4 automatically calculates risk-benefit contours, displaying the confidence associated with a specified scenario of minimum benefit and maximum risk of one treatment arm over the other. The spreadsheet is freely downloadable at www.ontumor.com/professional/statistics.htm A simple, self-explanatory, freely available spreadsheet calculator was developed using Excel 2000. The incorporated decision-making tools can be used for data analysis and improve the reporting of results of any

Prognostic significance of urokinase plasminogen activator and plasminogen activator inhibitor-1 mRNA expression in lymph node- and hormone receptor-positive breast cancer

International Nuclear Information System (INIS)

Leissner, Philippe; Verjat, Thibault; Bachelot, Thomas; Paye, Malick; Krause, Alexander; Puisieux, Alain; Mougin, Bruno

2006-01-01

One of the most thoroughly studied systems in relation to its prognostic relevance in patients with breast cancer, is the plasminogen activation system that comprises of, among others, the urokinase Plasminogen Activator (uPA) and its main inhibitor, the Plasminogen Activator Inhibitor-1 (PAI-1). In this study, we investigated the prognostic value of uPA and PAI-1 at the mRNA level in lymph node- and hormone receptor-positive breast cancer. The study included a retrospective series of 87 patients with hormone-receptor positive and axillary lymph node-positive breast cancer. All patients received radiotherapy, adjuvant anthracycline-based chemotherapy and five years of tamoxifen treatment. The median patient age was 54 and the median follow-up time was 79 months. Distant relapse occurred in 30 patients and 22 patients died from breast cancer during follow-up. We investigated the prognostic value of uPA and PAI-1 at the mRNA level as measured by real-time quantitative RT-PCR. uPA and PAI-1 gene expression was not found to be correlated with any of the established clinical and pathological factors. Metastasis-free Survival (MFS) and Breast Cancer specific Survival (BCS) were significantly shorter in patients expressing high levels of PAI-1 mRNA (p < 0.0001; p < 0.0001; respectively). In Cox multivariate analysis, the level of PAI-1 mRNA appeared to be the strongest prognostic factor for MFS (Hazard Ratio (HR) = 10.12; p = 0.0002) and for BCS (HR = 13.17; p = 0.0003). Furthermore, uPA gene expression was not significantly associated neither with MFS (p = 0.41) nor with BCS (p = 0.19). In a Cox-multivariate regression analysis, uPA expression did not demonstrate significant independent prognostic value. These findings indicate that high PAI-1 mRNA expression represents a strong and independent unfavorable prognostic factor for the development of metastases and for breast cancer specific survival in a population of hormone receptor- and lymph node-positive breast cancer

Prognostic significance of urokinase plasminogen activator and plasminogen activator inhibitor-1 mRNA expression in lymph node- and hormone receptor-positive breast cancer

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Krause Alexander

2006-08-01

Full Text Available Abstract Background One of the most thoroughly studied systems in relation to its prognostic relevance in patients with breast cancer, is the plasminogen activation system that comprises of, among others, the urokinase Plasminogen Activator (uPA and its main inhibitor, the Plasminogen Activator Inhibitor-1 (PAI-1. In this study, we investigated the prognostic value of uPA and PAI-1 at the mRNA level in lymph node- and hormone receptor-positive breast cancer. Methods The study included a retrospective series of 87 patients with hormone-receptor positive and axillary lymph node-positive breast cancer. All patients received radiotherapy, adjuvant anthracycline-based chemotherapy and five years of tamoxifen treatment. The median patient age was 54 and the median follow-up time was 79 months. Distant relapse occurred in 30 patients and 22 patients died from breast cancer during follow-up. We investigated the prognostic value of uPA and PAI-1 at the mRNA level as measured by real-time quantitative RT-PCR. Results uPA and PAI-1 gene expression was not found to be correlated with any of the established clinical and pathological factors. Metastasis-free Survival (MFS and Breast Cancer specific Survival (BCS were significantly shorter in patients expressing high levels of PAI-1 mRNA (p PAI-1 mRNA appeared to be the strongest prognostic factor for MFS (Hazard Ratio (HR = 10.12; p = 0.0002 and for BCS (HR = 13.17; p = 0.0003. Furthermore, uPA gene expression was not significantly associated neither with MFS (p = 0.41 nor with BCS (p = 0.19. In a Cox-multivariate regression analysis, uPA expression did not demonstrate significant independent prognostic value. Conclusion These findings indicate that high PAI-1 mRNA expression represents a strong and independent unfavorable prognostic factor for the development of metastases and for breast cancer specific survival in a population of hormone receptor- and lymph node-positive breast cancer patients.

A significant positive correlation between endogenous trans-zeatin content and total arsenic in arsenic hyperaccumulator Pteris cretica var. nervosa.

Science.gov (United States)

Zhang, Xuemei; Yang, Xiaoyan; Wang, Hongbin; Li, Qinchun; Wang, Haijuan; Li, Yanyan

2017-04-01

A pot experiment was conducted to compare the content of endogenous trans-zeatin (Z), plant arsenic (As) uptake and physiological indices in the fronds of As-hyperaccumulator (Pteris cretica var. nervosa) and non-hyperaccumulator (Pteris ensiformis). Furthermore, a stepwise regression method was used to study the relationship among determined indices, and the time-course effect of main indices was also investigated under 100mg/kg As stress with time extension. In the 100-200mg/kg As treatments, plant height showed no significant difference and endogenous Z content significantly increased in P. cretica var. nervosa compared to the control, but a significant decrease of height and endogenous Z was observed in P. ensiformis. The concentrations of As (III) and As (V) increased significantly in the fronds of two plants, but this increase was much higher in P. cretica var. nervosa. Compared to the control, the contents of chlorophyll and soluble protein were significantly increased in P. cretica var. nervosa but decreased in P. ensiformis in the 200mg/kg As treatment, respectively. A significant positive correlation was found between the contents of endogenous Z and total As in P. cretica var. nervosa, but such a correlation was not found in P. ensiformis. Additionally, in the time-course effect experiment, a peak value of each index was appeared in the 43rd day in two plants, except for chlorophyll in P. ensiformis, but this value was significantly higher in P. cretica var. nervosa than that in P. ensiformis. In conclusion, a higher endogenous Z content contributed to As accumulation of P. cretica var. nervosa under As stress. Copyright © 2016 Elsevier Inc. All rights reserved.

Significance of family and peer support for metabolic control of type 1 diabetes in adolescents

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Đurović Dušanka

2009-01-01

Full Text Available The aim of the paper was to explore the significance of family and peer support for metabolic control of Type 1 diabetes in adolescents. Metabolic control refers to maintenance of acceptable blood glucose level thus diminishing risk for chronic complications. It involves regular insulin shots, measuring blood glucose and keeping diary, as the daily based self-control. Regular visits to endocrinologist and screening for chronic complications are compulsory. The sample comprised 79 adolescents age 10-17 years with diagnose of Type 1 diabetes and properly treated at the institute. The sample was divided in two groups - with good (N=40 and poor (N=39 metabolic control. A criterium for good metabolic control was glycosilated hemoglobin less than 7,6%. Social support was measured by Social Support Scale consisting of two parts - the first for estimation of registered family support (based upon modified Perceived Social Support Family Scale and the second for estimation of registered friends' support (modified Perceived Social Support Friend Scale. Adolescents with good metabolic control referred statistically more significant social support in the family, unlike the group with poor metabolic control. Considering peer social support, there was no statistically significant difference. Positive family history for diabetes also appeared to be directly linked to good metabolic control.

Stability and equilibrium in quantum statistical mechanics

International Nuclear Information System (INIS)

Kastler, Daniel.

1975-01-01

A derivation of the Gibbs Ansatz, base of the equilibrium statistical mechanics is provided from a stability requirements, in technical connection with the harmonic analysis of non-commutative dynamical systems. By the same token a relation is established between stability and the positivity of Hamiltonian in the zero temperature case [fr

Exploration of variations in positions of upper and lower incisors, overjet, overbite, and irregularity index in orthodontic patients with dissimilar depths of curve of spee

International Nuclear Information System (INIS)

Kumari, N.; Fida, M.; Shaikh, A.

2017-01-01

The position and arrangement of teeth as well as the entire scheme of occlusion differs from one individual to the other .The purpose of this study was to examine differences in position and inclination of incisors, overjet, overbite and lower arch crowding in subjects with different depths of curve of Spee and to determine correlations between depth of curve of Spee and these variables. Methods: The sample comprised of 114 patients (55 females and 59 males) with fully erupted permanent second molars (age 12-25 years), having no history of previous orthodontic treatment, no craniofacial anomalies, and no missing permanent teeth. Study parameters were assessed by using pretreatment lateral cephalograms and dental casts of orthodontic patients. The entire sample was divided into three groups according to depth of curve of Spee (mild Spee=38, moderate Spee=38, severe Spee=38). Descriptive statistics were calculated. Differences between the Spee groups were assessed by analysis of variance. In addition, correlation coefficients were calculated between curve of Spee and other parameters. Results: Statistically significant differences were found in upper incisor inclination (p=0.000), lower incisor inclination (p=0.003), Steiner's mandibular plane angle (p=0.000), overjet (p=0.001), overbite (p=0.000) and irregularity index (p=0.008) among the Spee groups. Moreover, statistically significant positive correlations were found between curve of Spee and overjet, overbite and irregularity index. Upper and lower incisor inclinations as well as mandibular plane angle were found to have statistically significant but negative correlations with curve of Spee. Conclusion: Overjet and overbite in severe Spee group are larger than in mild and moderate Spee groups. There is negative correlation between curve of Spee depth and inclinations of upper and lower incisors. There is positive correlation between curve of Spee depth and severity of lower anterior crowding and Steiner

Review of the Statistical Techniques in Medical Sciences | Okeh ...

African Journals Online (AJOL)

... medical researcher in selecting the appropriate statistical techniques. Of course, all statistical techniques have certain underlying assumptions, which must be checked before the technique is applied. Keywords: Variable, Prospective Studies, Retrospective Studies, Statistical significance. Bio-Research Vol. 6 (1) 2008: pp.

Model output statistics applied to wind power prediction

Energy Technology Data Exchange (ETDEWEB)

Joensen, A; Giebel, G; Landberg, L [Risoe National Lab., Roskilde (Denmark); Madsen, H; Nielsen, H A [The Technical Univ. of Denmark, Dept. of Mathematical Modelling, Lyngby (Denmark)

1999-03-01

Being able to predict the output of a wind farm online for a day or two in advance has significant advantages for utilities, such as better possibility to schedule fossil fuelled power plants and a better position on electricity spot markets. In this paper prediction methods based on Numerical Weather Prediction (NWP) models are considered. The spatial resolution used in NWP models implies that these predictions are not valid locally at a specific wind farm. Furthermore, due to the non-stationary nature and complexity of the processes in the atmosphere, and occasional changes of NWP models, the deviation between the predicted and the measured wind will be time dependent. If observational data is available, and if the deviation between the predictions and the observations exhibits systematic behavior, this should be corrected for; if statistical methods are used, this approaches is usually referred to as MOS (Model Output Statistics). The influence of atmospheric turbulence intensity, topography, prediction horizon length and auto-correlation of wind speed and power is considered, and to take the time-variations into account, adaptive estimation methods are applied. Three estimation techniques are considered and compared, Extended Kalman Filtering, recursive least squares and a new modified recursive least squares algorithm. (au) EU-JOULE-3. 11 refs.

Self-Perceived Viral Load and Sexual Risk Behavior Among Known HIV-Positive MSM in San Francisco, 2014.

Science.gov (United States)

Guigayoma, John; Chen, Yea-Hung; Snowden, Jonathan M; Santos, Glenn-Milo; Hecht, Jennifer; Raymond, H Fisher

2017-07-01

Self-perceived viral suppression status among men who have sex with men (MSM) may impact HIV risk transmission behaviors. We conducted a 2014 cross-sectional survey of MSM in San Francisco and assessed differences in sexual risk behavior among known HIV-positive MSM based on viral suppression of HIV. We collected demographics, self-perceived viral load status, and sexual risk behavior and tested for viral load levels through laboratory assays. Men were categorized in a hierarchical schema of sexual risk behavior categories based on responses to questions regarding recent partners' HIV status, condom use, and sexual positioning. We used Fisher exact tests to assess for differences based on self-perceived viral load status. Out of a sample of 96 known HIV-positive men, 59 men self-reported an undetectable HIV viral load and 9 men self-reported a detectable viral load consented to confirmatory laboratory testing. The sample of self-reported undetectable men had gradually larger proportions of higher-risk sexual practices, whereas the sample of detectable men was evenly distributed across sexual practices. This association was not statistically significant (P = 0.91). Self-perceived viral suppression may influence sexual practices of known HIV-positive MSM, but small sample size, especially within the detectable category, hinders our ability to determine statistical significance. More research is necessary to assess how HIV-positive men account for viral load in sexual decision-making practices, and this research may inform resource allocation and clinical recommendations to maintain the health of MSM populations.

The expression and significance of P-glycoprotein, lung resistance protein and multidrug resistance-associated protein in gastric cancer

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Li Yan

2009-11-01

Full Text Available Abstract Background To detect the expression of multidrug resistance molecules P-glycoprotein (P-gp, Lung resistnce protein (LRP and Multidrug resistance-associated protein (MRP and analyze the relationship between them and the clinico-pathological features. Methods The expressions of P-gp, LRP and MRP in formalin-fixed paraffin-embedded tissue sections from 59 gastric cancer patients were determined by a labbelled Streptavidin-Peroxidase (SP immunohistochemical technique, and the results were analyzed in correlation with clinicopathological data. None of these patients received chemotherapy prior to surgery. Results The positive rates of P-gp, LRP, MRP were 86.4%, 84.7% and 27.1%, respectively. The difference between the positive rate of P-gp and MRP was significant statistically, as well as the difference between the expression of MRP and LRP. No significant difference was observed between P-gp and LRP, but the positively correlation between the expression of P-gp and LRP had been found. No significant correlation between the expression of P-gp, LRP, MRP and the grade of differentiation were observed. The expression of P-gp was correlated with clinical stages positively (r = 0.742, but the difference with the expression of P-gp in different stages was not significant. Conclusion The expressions of P-gp, LRP and MRP in patients with gastric cancer without prior chemotherapy are high, indicating that innate drug resistance may exist in gastric cancer.

Comparison of small n statistical tests of differential expression applied to microarrays

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Lee Anna Y

2009-02-01

Full Text Available Abstract Background DNA microarrays provide data for genome wide patterns of expression between observation classes. Microarray studies often have small samples sizes, however, due to cost constraints or specimen availability. This can lead to poor random error estimates and inaccurate statistical tests of differential expression. We compare the performance of the standard t-test, fold change, and four small n statistical test methods designed to circumvent these problems. We report results of various normalization methods for empirical microarray data and of various random error models for simulated data. Results Three Empirical Bayes methods (CyberT, BRB, and limma t-statistics were the most effective statistical tests across simulated and both 2-colour cDNA and Affymetrix experimental data. The CyberT regularized t-statistic in particular was able to maintain expected false positive rates with simulated data showing high variances at low gene intensities, although at the cost of low true positive rates. The Local Pooled Error (LPE test introduced a bias that lowered false positive rates below theoretically expected values and had lower power relative to the top performers. The standard two-sample t-test and fold change were also found to be sub-optimal for detecting differentially expressed genes. The generalized log transformation was shown to be beneficial in improving results with certain data sets, in particular high variance cDNA data. Conclusion Pre-processing of data influences performance and the proper combination of pre-processing and statistical testing is necessary for obtaining the best results. All three Empirical Bayes methods assessed in our study are good choices for statistical tests for small n microarray studies for both Affymetrix and cDNA data. Choice of method for a particular study will depend on software and normalization preferences.

Spectral and cross-spectral analysis of uneven time series with the smoothed Lomb-Scargle periodogram and Monte Carlo evaluation of statistical significance

Science.gov (United States)

Pardo-Igúzquiza, Eulogio; Rodríguez-Tovar, Francisco J.

2012-12-01

Many spectral analysis techniques have been designed assuming sequences taken with a constant sampling interval. However, there are empirical time series in the geosciences (sediment cores, fossil abundance data, isotope analysis, …) that do not follow regular sampling because of missing data, gapped data, random sampling or incomplete sequences, among other reasons. In general, interpolating an uneven series in order to obtain a succession with a constant sampling interval alters the spectral content of the series. In such cases it is preferable to follow an approach that works with the uneven data directly, avoiding the need for an explicit interpolation step. The Lomb-Scargle periodogram is a popular choice in such circumstances, as there are programs available in the public domain for its computation. One new computer program for spectral analysis improves the standard Lomb-Scargle periodogram approach in two ways: (1) It explicitly adjusts the statistical significance to any bias introduced by variance reduction smoothing, and (2) it uses a permutation test to evaluate confidence levels, which is better suited than parametric methods when neighbouring frequencies are highly correlated. Another novel program for cross-spectral analysis offers the advantage of estimating the Lomb-Scargle cross-periodogram of two uneven time series defined on the same interval, and it evaluates the confidence levels of the estimated cross-spectra by a non-parametric computer intensive permutation test. Thus, the cross-spectrum, the squared coherence spectrum, the phase spectrum, and the Monte Carlo statistical significance of the cross-spectrum and the squared-coherence spectrum can be obtained. Both of the programs are written in ANSI Fortran 77, in view of its simplicity and compatibility. The program code is of public domain, provided on the website of the journal (http://www.iamg.org/index.php/publisher/articleview/frmArticleID/112/). Different examples (with simulated and

The Importance of Medical Students' Attitudes Regarding Cognitive Competence for Teaching Applied Statistics: Multi-Site Study and Meta-Analysis.

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Natasa M Milic

Full Text Available The scientific community increasingly is recognizing the need to bolster standards of data analysis given the widespread concern that basic mistakes in data analysis are contributing to the irreproducibility of many published research findings. The aim of this study was to investigate students' attitudes towards statistics within a multi-site medical educational context, monitor their changes and impact on student achievement. In addition, we performed a systematic review to better support our future pedagogical decisions in teaching applied statistics to medical students.A validated Serbian Survey of Attitudes Towards Statistics (SATS-36 questionnaire was administered to medical students attending obligatory introductory courses in biostatistics from three medical universities in the Western Balkans. A systematic review of peer-reviewed publications was performed through searches of Scopus, Web of Science, Science Direct, Medline, and APA databases through 1994. A meta-analysis was performed for the correlation coefficients between SATS component scores and statistics achievement. Pooled estimates were calculated using random effects models.SATS-36 was completed by 461 medical students. Most of the students held positive attitudes towards statistics. Ability in mathematics and grade point average were associated in a multivariate regression model with the Cognitive Competence score, after adjusting for age, gender and computer ability. The results of 90 paired data showed that Affect, Cognitive Competence, and Effort scores demonstrated significant positive changes. The Cognitive Competence score showed the largest increase (M = 0.48, SD = 0.95. The positive correlation found between the Cognitive Competence score and students' achievement (r = 0.41; p<0.001, was also shown in the meta-analysis (r = 0.37; 95% CI 0.32-0.41.Students' subjective attitudes regarding Cognitive Competence at the beginning of the biostatistics course, which were

The Importance of Medical Students' Attitudes Regarding Cognitive Competence for Teaching Applied Statistics: Multi-Site Study and Meta-Analysis.

Science.gov (United States)

Milic, Natasa M; Masic, Srdjan; Milin-Lazovic, Jelena; Trajkovic, Goran; Bukumiric, Zoran; Savic, Marko; Milic, Nikola V; Cirkovic, Andja; Gajic, Milan; Kostic, Mirjana; Ilic, Aleksandra; Stanisavljevic, Dejana

2016-01-01

The scientific community increasingly is recognizing the need to bolster standards of data analysis given the widespread concern that basic mistakes in data analysis are contributing to the irreproducibility of many published research findings. The aim of this study was to investigate students' attitudes towards statistics within a multi-site medical educational context, monitor their changes and impact on student achievement. In addition, we performed a systematic review to better support our future pedagogical decisions in teaching applied statistics to medical students. A validated Serbian Survey of Attitudes Towards Statistics (SATS-36) questionnaire was administered to medical students attending obligatory introductory courses in biostatistics from three medical universities in the Western Balkans. A systematic review of peer-reviewed publications was performed through searches of Scopus, Web of Science, Science Direct, Medline, and APA databases through 1994. A meta-analysis was performed for the correlation coefficients between SATS component scores and statistics achievement. Pooled estimates were calculated using random effects models. SATS-36 was completed by 461 medical students. Most of the students held positive attitudes towards statistics. Ability in mathematics and grade point average were associated in a multivariate regression model with the Cognitive Competence score, after adjusting for age, gender and computer ability. The results of 90 paired data showed that Affect, Cognitive Competence, and Effort scores demonstrated significant positive changes. The Cognitive Competence score showed the largest increase (M = 0.48, SD = 0.95). The positive correlation found between the Cognitive Competence score and students' achievement (r = 0.41; p<0.001), was also shown in the meta-analysis (r = 0.37; 95% CI 0.32-0.41). Students' subjective attitudes regarding Cognitive Competence at the beginning of the biostatistics course, which were directly linked to

cMiCE: a high resolution animal PET using continuous LSO with a statistics based positioning scheme

International Nuclear Information System (INIS)

Joung Jinhun; Miyaoka, R.S.; Lewellen, T.K.

2002-01-01

Objective: Detector designs for small animal scanners are currently dominated by discrete crystal implementations. However, given the small crystal cross-sections required to obtain very high resolution, discrete designs are typically expensive, have low packing fraction, reduced light collection, and are labor intensive to build. To overcome these limitations we have investigated the feasibility of using a continuous miniature crystal element (cMiCE) detector module for high resolution small animal PET applications. Methods: The detector module consists of a single continuous slab of LSO, 25x25 mm 2 in exposed cross-section and 4 mm thick, coupled directly to a PS-PMT (Hamamatsu R5900-00-C12). The large area surfaces of the crystal were polished and painted with TiO 2 and the short surfaces were left unpolished and painted black. Further, a new statistics based positioning (SBP) algorithm has been implemented to address linearity and edge effect artifacts that are inherent with conventional Anger style positioning schemes. To characterize the light response function (LRF) of the detector, data were collected on a coarse grid using a highly collimated coincidence setup. The LRF was then estimated using cubic spline interpolation. Detector performance has been evaluated for both SBP and Anger based decoding using measured data and Monte Carlo simulations. Results: Using the SBP scheme, edge artifacts were successfully handled. Simulation results show that the useful field of view (UFOV) was extended to ∼22x22 mm 2 with an average point spread function of ∼0.5 mm full width of half maximum (FWHM PSF ). For the same detector with Anger decoding the UFOV of the detector was ∼16x16 mm 2 with an average FWHM PSP of ∼0.9 mm. Experimental results yielded similar differences between FOV and resolution performance. FWHM PSF for the SBP and Anger based method was 1.4 and 2.0 mm, uncorrected for source size, with a 1 mm diameter point source, respectively. Conclusion

Application of classical versus bayesian statistical control charts to on-line radiological monitoring

International Nuclear Information System (INIS)

DeVol, T.A.; Gohres, A.A.; Williams, C.L.

2009-01-01

False positive and false negative incidence rates of radiological monitoring data from classical and Bayesian statistical process control chart techniques are compared. The on-line monitoring for illicit radioactive material with no false positives or false negatives is the goal of homeland security monitoring, but is unrealistic. However, statistical fluctuations in the detector signal, short detection times, large source to detector distances, and shielding effects make distinguishing between a radiation source and natural background particularly difficult. Experimental time series data were collected using a 1' x 1' LaCl 3 (Ce) based scintillation detector (Scionix, Orlando, FL) under various simulated conditions. Experimental parameters include radionuclide (gamma-ray) energy, activity, density thickness (source to detector distance and shielding), time, and temperature. All statistical algorithms were developed using MATLAB TM . The Shewhart (3-σ) control chart and the cumulative sum (CUSUM) control chart are the classical procedures adopted, while the Bayesian technique is the Shiryayev-Roberts (S-R) control chart. The Shiryayev-Roberts method was the best method for controlling the number of false positive detects, followed by the CUSUM method. However, The Shiryayev-Roberts method, used without modification, resulted in one of the highest false negative incidence rates independent of the signal strength. Modification of The Shiryayev-Roberts statistical analysis method reduced the number of false negatives, but resulted in an increase in the false positive incidence rate. (author)

Statistical emulation of a tsunami model for sensitivity analysis and uncertainty quantification

Directory of Open Access Journals (Sweden)

A. Sarri

2012-06-01

Full Text Available Due to the catastrophic consequences of tsunamis, early warnings need to be issued quickly in order to mitigate the hazard. Additionally, there is a need to represent the uncertainty in the predictions of tsunami characteristics corresponding to the uncertain trigger features (e.g. either position, shape and speed of a landslide, or sea floor deformation associated with an earthquake. Unfortunately, computer models are expensive to run. This leads to significant delays in predictions and makes the uncertainty quantification impractical. Statistical emulators run almost instantaneously and may represent well the outputs of the computer model. In this paper, we use the outer product emulator to build a fast statistical surrogate of a landslide-generated tsunami computer model. This Bayesian framework enables us to build the emulator by combining prior knowledge of the computer model properties with a few carefully chosen model evaluations. The good performance of the emulator is validated using the leave-one-out method.

Distribution of anti-HAV IgM positivity according to age and months of a year in Van region,Turkey

Directory of Open Access Journals (Sweden)

Mehmet Parlak

2012-09-01

Full Text Available Objectives: In this study we investigated the anti-HAVIgM positivity rates and their distribution according to ageand season of a year in Van region of Turkey.Materials and methods: During five-year period between2006-2010, the presence of anti-HAV IgM weredetermined in the serum samples sent to our laboratorythat have prediagnosis of hepatitis A by ELISA test, usingAxSYM (Abbott Diagnostics, Germany and i2000SR Architect(Abbott Diagnostics, Germany analyzers. For statisticalanalyze of Anti-HAV IgM positivity rates, patients’age and gender and time of year when specimen wasobtain were compared.Results: The presence of anti-HAV IgM was investigatedin a total of 8851 patients, including 5303 (60% childrenand 3548 (40% adults. Anti-HAV IgM in children and adultpatients were determined as 9.8% and 2.6%, respectively,and this difference was found statistically significant (p<0.01. Anti-HAV IgM positivity rate began to rise in August,reached the highest level in November-Decemberand decreased to the initial level in January. The highestfrequency detected during the November-December periodwas statistically significantly higher than rates foundduring other months.Conclusions: The prevalence of Hepatitis A was found tobe similar with previous studies performed in our country.The prevalence of disease was significantly increased especiallybetween November and December.Key words: Anti-HAV IgM, seasonal distribution, seroprevalence,age

A statistical investigation of the mass discrepancy-acceleration relation

Science.gov (United States)

Desmond, Harry

2017-02-01

We use the mass discrepancy-acceleration relation (the correlation between the ratio of total-to-visible mass and acceleration in galaxies; MDAR) to test the galaxy-halo connection. We analyse the MDAR using a set of 16 statistics that quantify its four most important features: shape, scatter, the presence of a `characteristic acceleration scale', and the correlation of its residuals with other galaxy properties. We construct an empirical framework for the galaxy-halo connection in LCDM to generate predictions for these statistics, starting with conventional correlations (halo abundance matching; AM) and introducing more where required. Comparing to the SPARC data, we find that: (1) the approximate shape of the MDAR is readily reproduced by AM, and there is no evidence that the acceleration at which dark matter becomes negligible has less spread in the data than in AM mocks; (2) even under conservative assumptions, AM significantly overpredicts the scatter in the relation and its normalization at low acceleration, and furthermore positions dark matter too close to galaxies' centres on average; (3) the MDAR affords 2σ evidence for an anticorrelation of galaxy size and Hubble type with halo mass or concentration at fixed stellar mass. Our analysis lays the groundwork for a bottom-up determination of the galaxy-halo connection from relations such as the MDAR, provides concrete statistical tests for specific galaxy formation models, and brings into sharper focus the relative evidence accorded by galaxy kinematics to LCDM and modified gravity alternatives.

A weighted generalized score statistic for comparison of predictive values of diagnostic tests.

Science.gov (United States)

Kosinski, Andrzej S

2013-03-15

Positive and negative predictive values are important measures of a medical diagnostic test performance. We consider testing equality of two positive or two negative predictive values within a paired design in which all patients receive two diagnostic tests. The existing statistical tests for testing equality of predictive values are either Wald tests based on the multinomial distribution or the empirical Wald and generalized score tests within the generalized estimating equations (GEE) framework. As presented in the literature, these test statistics have considerably complex formulas without clear intuitive insight. We propose their re-formulations that are mathematically equivalent but algebraically simple and intuitive. As is clearly seen with a new re-formulation we presented, the generalized score statistic does not always reduce to the commonly used score statistic in the independent samples case. To alleviate this, we introduce a weighted generalized score (WGS) test statistic that incorporates empirical covariance matrix with newly proposed weights. This statistic is simple to compute, always reduces to the score statistic in the independent samples situation, and preserves type I error better than the other statistics as demonstrated by simulations. Thus, we believe that the proposed WGS statistic is the preferred statistic for testing equality of two predictive values and for corresponding sample size computations. The new formulas of the Wald statistics may be useful for easy computation of confidence intervals for difference of predictive values. The introduced concepts have potential to lead to development of the WGS test statistic in a general GEE setting. Copyright © 2012 John Wiley & Sons, Ltd.

Waiting time and the psychosocial consequences of false-positive mammography

DEFF Research Database (Denmark)

Heleno, Bruno M.; Siersma, Volkert; Brodersen, John

2015-01-01

Background: There is wide variation in the psychosocial response to false-positive mammography. We aimed to assess whether women having to wait longer to exclude cancer had increased psychosocial consequences that persisted after cancer was ruled out. Findings: We selected women with false......-positive mammography (n = 272), screened for breast cancer in Copenhagen and Funen (Denmark) over a 1-year period. We measured psychosocial consequences immediately before women attended their recall visit and 1, 6, 18 and 36 months after women received their final diagnosis. After women were told that cancer had been...... ruled out, adverse psychosocial consequences decreased with time. We found no statistically significant differences between women who had cancer ruled out immediately at the recall visit (waiting time of 0) and women who had to wait longer before cancer was ruled out (waiting times 1-30, 30...

The significance of lower jaw position in relation to postural stability. Comparison of a premanufactured occlusal splint with the Dental Power Splint.

Science.gov (United States)

Ohlendorf, D; Riegel, M; Lin Chung, T; Kopp, S

2013-01-01

The purpose of this study was to investigate the effects on postural stability of two different lower jaw positions held in place by splints with eyes open and eyes closed. The postural stability in 21 healthy adult volunteers was investigated using two different sets of occlusal conditions with the lower jaw being at rest either with the eyes opened or closed. Two occlusal splints (standard splint and DPS splint) were used in order to maintain this lower jaw position. The balance behaviour was recorded using a balance platform. In a comparison of the habitual occlusion with the two occlusal splints, the balance posturographic values with the eyes opened fell between 7-9% and those for weight distribution with the eyes closed between 22-26% (with greater improvement being achieved with DPS) with the result that the variability in the range of fluctuations was reduced. The level of positioning accuracy deteriorated with the wearing of a splint between 13% with the DPS splint and 30% with the standard splint. Gender-specific differences of minor importance in relation to the positioning accuracy were recorded, with there being significant differences in the female participants (P≤0.00). An occlusal change in the stomatognathic system impacts on postural stability. Balance deficits seem to correlate with deteriorated body sway, which, according to the results, can be improved by a myocentric bite position using a DPS splint. This is more the case with the eyes closed than with the eyes opened.

Statistical thermodynamics

International Nuclear Information System (INIS)

Lim, Gyeong Hui

2008-03-01

This book consists of 15 chapters, which are basic conception and meaning of statistical thermodynamics, Maxwell-Boltzmann's statistics, ensemble, thermodynamics function and fluctuation, statistical dynamics with independent particle system, ideal molecular system, chemical equilibrium and chemical reaction rate in ideal gas mixture, classical statistical thermodynamics, ideal lattice model, lattice statistics and nonideal lattice model, imperfect gas theory on liquid, theory on solution, statistical thermodynamics of interface, statistical thermodynamics of a high molecule system and quantum statistics

Change and clinical significance of serum PG in patients with chronic gastritis

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Wei-Hua Huan

2017-06-01

Full Text Available Objective: To observe the change and clinical significance of serum PG in patients with chronic atrophic gastritis (CAG. Methods: ELISA was used to detect the peripheral blood PG level in patients confirmed with CAG, gastric polyps, and gastric cancer who were admitted in our hospital from January, 2015 to January, 2016. The normal individuals who came for physical examinations were served as the control group. The peripheral blood PG level in patients with various gastric diseases was observed. Results: The serum PG Ⅰ expression and PG I/PG Ⅱ in the gastritis group were significantly lower than those in the gastric polyps group and control group, but were significantly higher than those in the gastric cancer group; while PG Ⅱ expression was significantly higher than that in the gastric polyps group and control group, but was significantly lower than those in the gastric cancer group. PG Ⅰ expression and PG I/ PG Ⅱ in the gastric polyps group were significantly higher than those in the gastritis group and gastric cancer group, while PG Ⅱ expression was significantly lower than that in the gastritis group and gastric cancer group. PG Ⅰ expression and PG I/ PG Ⅱ in the gastric cancer group were significantly lower than those in the other three groups, while PG Ⅱ expression was significantly higher than that in the other three groups. The serum PG Ⅰ expression in patients with positive HP infection in the gastritis group and gastric cancer group was significantly higher than that in patients with negative HP infection, but the comparison of PG I/ PG Ⅱ was not statistically significant. The serum PG Ⅰ expression and PG I/ PG Ⅱ in patients with negative and positive HP infection in the gastritis group were significantly higher than those in patients with negative and positive HP infection in the gastric cancer group; while PG Ⅱ expression was significantly was significantly lower than that in the gastric cancer group

Socio-Economic Position and Suicidal Ideation in Men

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Jane Pirkis

2017-03-01

Full Text Available People in low socio-economic positions are over-represented in suicide statistics and are at heightened risk for non-fatal suicidal thoughts and behaviours. Few studies have tried to tease out the relationship between individual-level and area-level socio-economic position, however. We used data from Ten to Men (the Australian Longitudinal Study on Male Health to investigate the relationship between individual-level and area-level socio-economic position and suicidal thinking in 12,090 men. We used a measure of unemployment/employment and occupational skill level as our individual-level indicator of socio-economic position. We used the Index of Relative Socio-Economic Disadvantage (a composite multidimensional construct created by the Australian Bureau of Statistics that combines information from a range of area-level variables, including the prevalence of unemployment and employment in low skilled occupations as our area-level indicator. We assessed suicidal thinking using the Patient Health Questionnaire (PHQ-9. We found that even after controlling for common predictors of suicidal thinking; low individual-level and area-level socio-economic position heightened risk. Individual-level socio-economic position appeared to exert the greater influence of the two; however. There is an onus on policy makers and planners from within and outside the mental health sector to take individual- and area-level socio-economic position into account when they are developing strategic initiatives.

Clinical and angiographic predictors of haemodynamically significant angiographic lesions: development and validation of a risk score to predict positive fractional flow reserve.

Science.gov (United States)

Sareen, Nishtha; Baber, Usman; Kezbor, Safwan; Sayseng, Sonny; Aquino, Melissa; Mehran, Roxana; Sweeny, Joseph; Barman, Nitin; Kini, Annapoorna; Sharma, Samin K

2017-04-07

Coronary revascularisation based upon physiological evaluation of lesions improves clinical outcomes. Angiographic or visual stenosis assessment alone is insufficient in predicting haemodynamic stenosis severity by fractional flow reserve (FFR) and therefore cannot be used to guide revascularisation, particularly in the lesion subset system formulated. Of 1,023 consecutive lesions (883 patients), 314 (31%) were haemodynamically significant. Characteristics associated with FFR ≤0.8 include male gender, higher SYNTAX score, lesions ≥20 mm, stenosis >50%, bifurcation, calcification, absence of tortuosity and smaller reference diameter. A user-friendly integer score was developed with the five variables demonstrating the strongest association. On prospective validation (in 279 distinct lesions), the increasing value of the score correlated well with increasing haemodynamic significance (C-statistic 0.85). We identified several clinical and angiographic characteristics and formulated a scoring system to guide the approach to intermediate lesions. This may translate into cost savings. Larger studies with prospective validation are required to confirm our results.

Prognostic significance of interleukin-8 and CD163-positive cell-infiltration in tumor tissues in patients with oral squamous cell carcinoma.

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Yohei Fujita

Full Text Available PURPOSE: We investigated whether serum interleukin (IL-8 reflects the tumor microenvironment and has prognostic value in patients with oral squamous cell carcinoma (OSCC. EXPERIMENTAL DESIGN: Fifty OSCC patients who received radical resection of their tumor(s were enrolled. Preoperative sera were measured for IL-8 by ELISA. Expression of IL-8 and the infiltration of immune cells in tumor tissues were analyzed by an immunohistochemical staining of surgical specimens. RESULTS: We found that disease-free survival (DFS was significantly longer in the Stage I/II OSCC patients with low serum IL-8 levels compared to those with high levels (p = 0.001. The tumor expression of IL-8, i.e., IL-8(T and the density of CD163-positive cells in the tumor invasive front, i.e., CD163(IF were correlated with the serum IL-8 level (p = 0.033 and p = 0.038, respectively, and they were associated with poor clinical outcome (p = 0.007 and p = 0.002, respectively, in DFS in all patients. A multivariate analysis revealed that N status, IL-8(T and CD163(IF significantly affected the DFS of the patients. Further analysis suggested that combination of N status with serum IL-8, IL-8(T or CD163(IF may be a new criterion for discriminating between OSCC patients at high and low risk for tumor relapse. Interestingly, the in vitro experiments demonstrated that IL-8 enhanced generation of CD163-positive M2 macrophages from peripheral blood monocytes, and that the cells produced IL-10. CONCLUSIONS: These findings indicate that IL-8 may be involved in poor clinical outcomes via generation of CD163-positive M2 macrophages, and that these factors in addition to N status may have prognostic value in patients with resectable OSCSS.

Position and width of normal adult optic chiasm as measured in coronal MRI

International Nuclear Information System (INIS)

Kim, Myung Soon; Park, Jin Sook

1994-01-01

To evaluate the position and transverse dimension of the adult optic chiasm in normal Korean adult. The authors analysed 3D coronal volume images (TR/TE=30/13, flip angle=30 .deg. ) of 136 normal adult subjects without known visual abnormality. All MRI examinations were performed using a 0.5T system. MRI was reviewed retrospectively to determine the position (horizontal and tilted) of the potic chiosm and the transverse dimension of the optic chiasm was measured. Seventy- five (55%) of the 136 normal subjects had horizontal position, and sixty-one (45%) had tilted position. Thirty- eight (62%) of 61 with tilted position showed higher position on the right side, and twenty-three (38%) showed higher position on the side. The average transverse dimension(mean SD) was 15.2 ± 0.7mm in men and 14.6 ± 1.0mm in women. The difference of transverse dimension between men and women was statistically significant. Tilted position of the adult optic chiasm on coronal MRI was seen in approximately half of normal adults. The average of transverse dimension of normal optic chiasm was 15mm

Infant Directed Speech Enhances Statistical Learning in Newborn Infants: An ERP Study.

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Alexis N Bosseler

Full Text Available Statistical learning and the social contexts of language addressed to infants are hypothesized to play important roles in early language development. Previous behavioral work has found that the exaggerated prosodic contours of infant-directed speech (IDS facilitate statistical learning in 8-month-old infants. Here we examined the neural processes involved in on-line statistical learning and investigated whether the use of IDS facilitates statistical learning in sleeping newborns. Event-related potentials (ERPs were recorded while newborns were exposed to12 pseudo-words, six spoken with exaggerated pitch contours of IDS and six spoken without exaggerated pitch contours (ADS in ten alternating blocks. We examined whether ERP amplitudes for syllable position within a pseudo-word (word-initial vs. word-medial vs. word-final, indicating statistical word learning and speech register (ADS vs. IDS would interact. The ADS and IDS registers elicited similar ERP patterns for syllable position in an early 0-100 ms component but elicited different ERP effects in both the polarity and topographical distribution at 200-400 ms and 450-650 ms. These results provide the first evidence that the exaggerated pitch contours of IDS result in differences in brain activity linked to on-line statistical learning in sleeping newborns.

Statistical modeling of Earth's plasmasphere

Science.gov (United States)

Veibell, Victoir

The behavior of plasma near Earth's geosynchronous orbit is of vital importance to both satellite operators and magnetosphere modelers because it also has a significant influence on energy transport, ion composition, and induced currents. The system is highly complex in both time and space, making the forecasting of extreme space weather events difficult. This dissertation examines the behavior and statistical properties of plasma mass density near geosynchronous orbit by using both linear and nonlinear models, as well as epoch analyses, in an attempt to better understand the physical processes that precipitates and drives its variations. It is shown that while equatorial mass density does vary significantly on an hourly timescale when a drop in the disturbance time scale index ( Dst) was observed, it does not vary significantly between the day of a Dst event onset and the day immediately following. It is also shown that increases in equatorial mass density were not, on average, preceded or followed by any significant change in the examined solar wind or geomagnetic variables, including Dst, despite prior results that considered a few selected events and found a notable influence. It is verified that equatorial mass density and and solar activity via the F10.7 index have a strong correlation, which is stronger over longer timescales such as 27 days than it is over an hourly timescale. It is then shown that this connection seems to affect the behavior of equatorial mass density most during periods of strong solar activity leading to large mass density reactions to Dst drops for high values of F10.7. It is also shown that equatorial mass density behaves differently before and after events based on the value of F10.7 at the onset of an equatorial mass density event or a Dst event, and that a southward interplanetary magnetic field at onset leads to slowed mass density growth after event onset. These behavioral differences provide insight into how solar and geomagnetic

Suppressor Effects of Positive and Negative Religious Coping on Academic Burnout Among Korean Middle School Students.

Science.gov (United States)

Noh, Hyunkyung; Chang, Eunbi; Jang, Yoojin; Lee, Ji Hae; Lee, Sang Min

2016-02-01

Statistical suppressor effects in prediction models can provide evidence of the interdependent relationship of independent variables. In this study, the suppressor effects of positive and negative religious coping on academic burnout were examined using longitudinal data. First, 388 middle school students reported their type of religion and use of positive and negative religious coping strategies. Four months later, they also reported their level of academic burnout. From structural equation modeling, significant suppressor effects were found among religious students. That is, the coefficients became larger when both positive and negative religious coping predicted academic burnout simultaneously, compared to when each religious coping predicted academic burnout alone. However, suppressor effects were not found among non-religious students.

[Statistics for statistics?--Thoughts about psychological tools].

Science.gov (United States)

Berger, Uwe; Stöbel-Richter, Yve

2007-12-01

Statistical methods take a prominent place among psychologists' educational programs. Being known as difficult to understand and heavy to learn, students fear of these contents. Those, who do not aspire after a research carrier at the university, will forget the drilled contents fast. Furthermore, because it does not apply for the work with patients and other target groups at a first glance, the methodological education as a whole was often questioned. For many psychological practitioners the statistical education makes only sense by enforcing respect against other professions, namely physicians. For the own business, statistics is rarely taken seriously as a professional tool. The reason seems to be clear: Statistics treats numbers, while psychotherapy treats subjects. So, does statistics ends in itself? With this article, we try to answer the question, if and how statistical methods were represented within the psychotherapeutical and psychological research. Therefore, we analyzed 46 Originals of a complete volume of the journal Psychotherapy, Psychosomatics, Psychological Medicine (PPmP). Within the volume, 28 different analyse methods were applied, from which 89 per cent were directly based upon statistics. To be able to write and critically read Originals as a backbone of research, presumes a high degree of statistical education. To ignore statistics means to ignore research and at least to reveal the own professional work to arbitrariness.

Effect of the absolute statistic on gene-sampling gene-set analysis methods.

Science.gov (United States)

Nam, Dougu

2017-06-01

Gene-set enrichment analysis and its modified versions have commonly been used for identifying altered functions or pathways in disease from microarray data. In particular, the simple gene-sampling gene-set analysis methods have been heavily used for datasets with only a few sample replicates. The biggest problem with this approach is the highly inflated false-positive rate. In this paper, the effect of absolute gene statistic on gene-sampling gene-set analysis methods is systematically investigated. Thus far, the absolute gene statistic has merely been regarded as a supplementary method for capturing the bidirectional changes in each gene set. Here, it is shown that incorporating the absolute gene statistic in gene-sampling gene-set analysis substantially reduces the false-positive rate and improves the overall discriminatory ability. Its effect was investigated by power, false-positive rate, and receiver operating curve for a number of simulated and real datasets. The performances of gene-set analysis methods in one-tailed (genome-wide association study) and two-tailed (gene expression data) tests were also compared and discussed.

A statistical model for porous structure of rocks

Institute of Scientific and Technical Information of China (English)

JU Yang; YANG YongMing; SONG ZhenDuo; XU WenJing

2008-01-01

The geometric features and the distribution properties of pores in rocks were In-vestigated by means of CT scanning tests of sandstones. The centroidal coordl-nares of pores, the statistic characterristics of pore distance, quantity, size and their probability density functions were formulated in this paper. The Monte Carlo method and the random number generating algorithm were employed to generate two series of random numbers with the desired statistic characteristics and prob-ability density functions upon which the random distribution of pore position, dis-tance and quantity were determined. A three-dimensional porous structural model of sandstone was constructed based on the FLAC3D program and the information of the pore position and distribution that the series of random numbers defined. On the basis of modelling, the Brazil split tests of rock discs were carried out to ex-amine the stress distribution, the pattern of element failure and the inoaculation of failed elements. The simulation indicated that the proposed model was consistent with the realistic porous structure of rock in terms of their statistic properties of pores and geometric similarity. The built-up model disclosed the influence of pores on the stress distribution, failure mode of material elements and the inosculation of failed elements.

A statistical model for porous structure of rocks

Institute of Scientific and Technical Information of China (English)

2008-01-01

The geometric features and the distribution properties of pores in rocks were in- vestigated by means of CT scanning tests of sandstones. The centroidal coordi- nates of pores, the statistic characterristics of pore distance, quantity, size and their probability density functions were formulated in this paper. The Monte Carlo method and the random number generating algorithm were employed to generate two series of random numbers with the desired statistic characteristics and prob- ability density functions upon which the random distribution of pore position, dis- tance and quantity were determined. A three-dimensional porous structural model of sandstone was constructed based on the FLAC3D program and the information of the pore position and distribution that the series of random numbers defined. On the basis of modelling, the Brazil split tests of rock discs were carried out to ex- amine the stress distribution, the pattern of element failure and the inosculation of failed elements. The simulation indicated that the proposed model was consistent with the realistic porous structure of rock in terms of their statistic properties of pores and geometric similarity. The built-up model disclosed the influence of pores on the stress distribution, failure mode of material elements and the inosculation of failed elements.

A statistical approach to determining the uncertainty of peat thickness

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J. Torppa

2011-06-01

Full Text Available This paper presents statistical studies of peat thickness to define its expected maximum variation (∆dm(∆r as a function of separation distance Δr. The aim was to provide an estimate of the observational uncertainty in peat depth due to positioning error, and the prediction uncertainty of the computed model. The data were GPS position and ground penetrating radar depth measurements of six mires in different parts of Finland. The calculated observational uncertainty for Finnish mires in general caused, for example, by a 20 m positioning error, is 43 cm in depth with 95 % confidence. The peat depth statistics differed among the six mires, and it is recommended that the mire specific function ∆dm(∆r is defined for each individual mire to obtain the best estimate of observational uncertainty. Knowledge of the observational error and function ∆dm(∆r should be used in peat depth modelling for defining the uncertainty of depth predictions.

On a curvature-statistics theorem

International Nuclear Information System (INIS)

Calixto, M; Aldaya, V

2008-01-01

The spin-statistics theorem in quantum field theory relates the spin of a particle to the statistics obeyed by that particle. Here we investigate an interesting correspondence or connection between curvature (κ = ±1) and quantum statistics (Fermi-Dirac and Bose-Einstein, respectively). The interrelation between both concepts is established through vacuum coherent configurations of zero modes in quantum field theory on the compact O(3) and noncompact O(2; 1) (spatial) isometry subgroups of de Sitter and Anti de Sitter spaces, respectively. The high frequency limit, is retrieved as a (zero curvature) group contraction to the Newton-Hooke (harmonic oscillator) group. We also make some comments on the physical significance of the vacuum energy density and the cosmological constant problem.

On a curvature-statistics theorem

Energy Technology Data Exchange (ETDEWEB)

Calixto, M [Departamento de Matematica Aplicada y Estadistica, Universidad Politecnica de Cartagena, Paseo Alfonso XIII 56, 30203 Cartagena (Spain); Aldaya, V [Instituto de Astrofisica de Andalucia, Apartado Postal 3004, 18080 Granada (Spain)], E-mail: Manuel.Calixto@upct.es

2008-08-15

The spin-statistics theorem in quantum field theory relates the spin of a particle to the statistics obeyed by that particle. Here we investigate an interesting correspondence or connection between curvature ({kappa} = {+-}1) and quantum statistics (Fermi-Dirac and Bose-Einstein, respectively). The interrelation between both concepts is established through vacuum coherent configurations of zero modes in quantum field theory on the compact O(3) and noncompact O(2; 1) (spatial) isometry subgroups of de Sitter and Anti de Sitter spaces, respectively. The high frequency limit, is retrieved as a (zero curvature) group contraction to the Newton-Hooke (harmonic oscillator) group. We also make some comments on the physical significance of the vacuum energy density and the cosmological constant problem.

The influence of occupant anthropometry and seat position on ejection risk in a rollover.

Science.gov (United States)

Atkinson, Theresa; Fras, Andrew; Telehowski, Paul

2010-08-01

During rollover crashes, ejection increases an occupant's risk of severe to fatal injury as compared to risks for those retained in the vehicle. The current study examined whether occupant anthropometry might influence ejection risk. Factors such as restraint use/disuse, seating position, vehicle type, and roll direction were also considered in the analysis. The current study examined occupant ejections in 10 years of National Automotive Sampling System (NASS) single-event rollovers of passenger vehicles and light trucks. Statistical analysis of unweighted and weighted ejection data was carried out. No statistically significant differences in ejection rates were found based on occupant height, age, or body mass index. Drivers were ejected significantly more frequently than other occupants: 62 percent of unrestrained drivers were ejected vs. 51 percent unrestrained right front occupants. Second row unrestrained occupants were ejected at rates similar to right front-seated occupants. There were no significant differences in ejection rates for near- vs. far-side occupants. These data suggest that assessment of ejection prevention systems using either a 50th or 5th percentile adult anthropomorphic test dummy (ATD) might provide a reasonable measure of system function for a broad range of occupants. They also support the development of ejection mitigation technologies that extend beyond the first row to protect occupants in rear seat positions. Future studies should consider potential interaction effects (i.e., occupant size and vehicle dimensions) and the influence of occupant size on ejection risk in non-single-event rollovers.

A comparison of two gluteus maximus EMG maximum voluntary isometric contraction positions

Directory of Open Access Journals (Sweden)

Bret Contreras

2015-09-01

Full Text Available Background. The purpose of this study was to compare the peak electromyography (EMG of the most commonly-used position in the literature, the prone bent-leg (90° hip extension against manual resistance applied to the distal thigh (PRONE, to a novel position, the standing glute squeeze (SQUEEZE.Methods. Surface EMG electrodes were placed on the upper and lower gluteus maximus of thirteen recreationally active females (age = 28.9 years; height = 164 cm; body mass = 58.2 kg, before three maximum voluntary isometric contraction (MVIC trials for each position were obtained in a randomized, counterbalanced fashion.Results. No statistically significant (p < 0.05 differences were observed between PRONE (upper: 91.94%; lower: 94.52% and SQUEEZE (upper: 92.04%; lower: 85.12% for both the upper and lower gluteus maximus. Neither the PRONE nor SQUEEZE was more effective between all subjects.Conclusions. In agreement with other studies, no single testing position is ideal for every participant. Therefore, it is recommended that investigators employ multiple MVIC positions, when possible, to ensure accuracy. Future research should investigate a variety of gluteus maximus MVIC positions in heterogeneous samples.

Continuous positive airway pressure treatment increases bronchial reactivity in obstructive sleep apnea patients.

Science.gov (United States)

Korczynski, Piotr; Gorska, Katarzyna; Przybylowski, Tadeusz; Bielicki, Piotr; Zielinski, Jan; Chazan, Ryszarda

2009-01-01

The effects of continuous positive airway pressure (CPAP) treatment on the function of the lower airways are poorly understood. One of the methods used to determine the influence of positive pressure breathing on lower airways is the bronchial hyperreactivity test. Some authors report that CPAP increases bronchial hyperreactivity, while others report decreases. To assess the influence of CPAP treatment on bronchial reactivity and the effects of bronchial hyperreactivity on compliance to CPAP treatment. The study group consisted of 101 obstructive sleep apnea syndrome patients (88 men and 13 women) with a mean age of 51 ± 11 years, mean apnea-hypopnea index of 53 ± 20 and mean body mass index of 32.6 ± 5.4. Patients were randomly assigned to a treatment group that received 3 weeks of CPAP therapy (group 1) or to a nontreatment control group (group 2). Pulmonary function tests and the methacholine bronchial provocation test were performed at baseline and 3 weeks later. There were no statistically significant differences between treated and control groups in anthropometry and polysomnography variables. At baseline, bronchial hyperreactivity was found in 6 patients from group 1 and 5 patients from group 2. A significant increase in bronchial reactivity was observed after CPAP treatment. Log PC20M decreased from 1.38 ± 0.30 at baseline to 1.26 ± 0.50 (p bronchial hyperreactivity during CPAP treatment were characterized by significantly lower FEV1, FVC and MEF50 values. CPAP produces statistically significant bronchial hyperreactivity. However, there were no clinical symptoms and it is not necessary to withdraw previous therapies. Copyright © 2009 S. Karger AG, Basel.

Positive emotion communication: Fostering well-being at end of life.

Science.gov (United States)

Terrill, Alexandra L; Ellington, Lee; John, Kevin K; Latimer, Seth; Xu, Jiayun; Reblin, Maija; Clayton, Margaret F

2018-04-01

Little is known about positive emotion communication (PEC) in end-of-life care. This study aims to identify types and patterns of PEC among hospice nurses, caregivers, and patients. A coding system based on positive psychology theory was applied as a secondary analysis to audio recordings of hospice nurse home visits with cancer patients and family caregivers, collected as part of a prospective longitudinal study. Eighty recordings (4 visits from 20 triads) were coded for humor, connection, praise, positive focus, gratitude, taking joy/savoring, and perfunctory statements. Descriptive statistics revealed the greatest proportion of PEC was made by nurses. Humor was most frequently used across all speakers. Cluster analysis revealed four PEC visit types: Savor/Take Joy; Humor; Perfunctory; and Other-focused Expressions of Positive Emotions. Linear mixed effect regression was used to estimate the trajectory of PEC over time, but no significant change was found. We found that positive emotions are common in nurse, caregiver and patient communication at end-of-life and do not decline closer to death. This study is among the first to explore PEC at end-of-life, and offers a way to bring strengths-based approaches into end of life communication research. Copyright © 2017 Elsevier B.V. All rights reserved.

Testing statistical hypotheses of equivalence

CERN Document Server

Wellek, Stefan

2010-01-01

Equivalence testing has grown significantly in importance over the last two decades, especially as its relevance to a variety of applications has become understood. Yet published work on the general methodology remains scattered in specialists' journals, and for the most part, it focuses on the relatively narrow topic of bioequivalence assessment.With a far broader perspective, Testing Statistical Hypotheses of Equivalence provides the first comprehensive treatment of statistical equivalence testing. The author addresses a spectrum of specific, two-sided equivalence testing problems, from the

Glycophospholipid Formulation with NADH and CoQ10 Significantly Reduces Intractable Fatigue in Western Blot-Positive ‘Chronic Lyme Disease’ Patients: Preliminary Report

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Garth L. Nicolson

2012-03-01

Full Text Available Background: An open label 8-week preliminary study was conducted in a small number of patients to determine if a combination oral supplement containing a mixture of phosphoglycolipids, coenzyme Q10 and microencapsulated NADH and other nutrients could affect fatigue levels in long-term, Western blot-positive, multi-symptom ‘chronic Lyme disease’ patients (also called ‘post-treatment Lyme disease’ or ‘post Lyme syndrome’ with intractable fatigue. Methods: The subjects in this study were 6 males (mean age = 45.1 ± 12.4 years and 10 females (mean age = 54.6 ± 7.4 years with ‘chronic Lyme disease’ (determined by multiple symptoms and positive Western blot analysis that had been symptomatic with chronic fatigue for an average of 12.7 ± 6.6 years. They had been seen by multiple physicians (13.3 ± 7.6 and had used many other remedies, supplements and drugs (14.4 ± 7.4 without fatigue relief. Fatigue was monitored at 0, 7, 30 and 60 days using a validated instrument, the Piper Fatigue Scale.Results: Patients in this preliminary study responded to the combination test supplement, showing a 26% reduction in overall fatigue by the end of the 8-week trial (p< 0.0003. Analysis of subcategories of fatigue indicated that there were significant improvements in the ability to complete tasks and activities as well as significant improvements in mood and cognitive abilities. Regression analysis of the data indicated that reductions in fatigue were consistent and occurred with a high degree of confidence (R2= 0.998. Functional Foods in Health and Disease 2012, 2(3:35-47 Conclusions: The combination supplement was a safe and effective method to significantly reduce intractable fatigue in long-term patients with Western blot-positive ‘chronic Lyme disease.’

Error analysis of terrestrial laser scanning data by means of spherical statistics and 3D graphs.

Science.gov (United States)

Cuartero, Aurora; Armesto, Julia; Rodríguez, Pablo G; Arias, Pedro

2010-01-01

This paper presents a complete analysis of the positional errors of terrestrial laser scanning (TLS) data based on spherical statistics and 3D graphs. Spherical statistics are preferred because of the 3D vectorial nature of the spatial error. Error vectors have three metric elements (one module and two angles) that were analyzed by spherical statistics. A study case has been presented and discussed in detail. Errors were calculating using 53 check points (CP) and CP coordinates were measured by a digitizer with submillimetre accuracy. The positional accuracy was analyzed by both the conventional method (modular errors analysis) and the proposed method (angular errors analysis) by 3D graphics and numerical spherical statistics. Two packages in R programming language were performed to obtain graphics automatically. The results indicated that the proposed method is advantageous as it offers a more complete analysis of the positional accuracy, such as angular error component, uniformity of the vector distribution, error isotropy, and error, in addition the modular error component by linear statistics.

Position estimation of transceivers in communication networks

Science.gov (United States)

Kent, Claudia A [Pleasanton, CA; Dowla, Farid [Castro Valley, CA

2008-06-03

This invention provides a system and method using wireless communication interfaces coupled with statistical processing of time-of-flight data to locate by position estimation unknown wireless receivers. Such an invention can be applied in sensor network applications, such as environmental monitoring of water in the soil or chemicals in the air where the position of the network nodes is deemed critical. Moreover, the present invention can be arranged to operate in areas where a Global Positioning System (GPS) is not available, such as inside buildings, caves, and tunnels.

Key World Energy Statistics

Energy Technology Data Exchange (ETDEWEB)

NONE

2010-07-01

The IEA produced its first handy, pocket-sized summary of key energy data in 1997. This new edition responds to the enormously positive reaction to the book since then. Key World Energy Statistics produced by the IEA contains timely, clearly-presented data on supply, transformation and consumption of all major energy sources. The interested businessman, journalist or student will have at his or her fingertips the annual Canadian production of coal, the electricity consumption in Thailand, the price of diesel oil in Spain and thousands of other useful energy facts. It exists in different formats to suit our readers' requirements.

Enhancing the Statistical Filtering Scheme to Detect False Negative Attacks in Sensor Networks

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Muhammad Akram

2017-06-01

Full Text Available In this paper, we present a technique that detects both false positive and false negative attacks in statistical filtering-based wireless sensor networks. In statistical filtering scheme, legitimate reports are repeatedly verified en route before they reach the base station, which causes heavy energy consumption. While the original statistical filtering scheme detects only false reports, our proposed method promises to detect both attacks.

Utility of gastric aspirates for diagnosing tuberculosis in children in a low prevalence area: predictors of positive cultures and significance of non-tuberculous mycobacteria.

Science.gov (United States)

Kordy, Faisal; Richardson, Susan E; Stephens, Derek; Lam, Ray; Jamieson, Frances; Kitai, Ian

2015-01-01

In countries with low rates of tuberculosis (TB), yields of gastric aspirates (GAs) for Mycobacterium tuberculosis (MTB) culture are low. The significance of non-tuberculous mycobacteria (NTM) isolated from GA is uncertain. We reviewed clinical, microbiologic and radiologic data for children who underwent GA between 1999 and 2011 at Sick Kids, Toronto. Radiologic features of cases were compared with those of age matched controls. 785 GAs were obtained from 285 patients of whom 20 (7%) had positive MTB cultures: in 15 patients the GA was the only positive culture for MTB. Of 15 culture-positive patients who underwent exactly 3 GAs, MTB was isolated from the first lavage in 10 (67%), only from the second in 3 (20%) and only from the third in 2 (13%). On univariate analysis, miliary disease and intrathoracic lymphadenopathy were associated with a positive GA MTB culture. On multiple conditional logistic regression analysis, adenopathy remained significant (OR 10.2 [95% CI 2.0-51.4] p =0.005). Twelve patients had NTM isolated, most commonly M. avium complex: none had evidence of invasive NTM disease during a median duration of 12 months of follow-up. Causal pathogens different from the GA NTM culture were isolated from biopsies or bronchoalveolar lavage in 3. GAs continue to be important for TB diagnosis in children. Three GAs have a yield better than 1. Those with miliary or disseminated TB and intrathoracic lymphadenopathy have highest yields. NTM isolates from GA are likely unimportant and can be clinically misleading.

λ (Δim) -statistical convergence of order α

Science.gov (United States)

Colak, Rifat; Et, Mikail; Altin, Yavuz

2017-09-01

In this study, using the generalized difference operator Δim and a sequence λ = (λn) which is a non-decreasing sequence of positive numbers tending to ∞ such that λn+1 ≤ λn+1, λ1 = 1, we introduce the concepts of λ (Δim) -statistical convergence of order α (α ∈ (0, 1]) and strong λ (Δim) -Cesàro summablility of order α (α > 0). We establish some connections between λ (Δim) -statistical convergence of order α and strong λ (Δim) -Cesàro summablility of order α. It is shown that if a sequence is strongly λ (Δim) -Cesàro summable of order α, then it is λ (Δim) -statistically convergent of order β in case 0 < α ≤ β ≤ 1.

SU-E-T-377: Inaccurate Positioning Might Introduce Significant MapCheck Calibration Error in Flatten Filter Free Beams

International Nuclear Information System (INIS)

Wang, S; Chao, C; Chang, J

2014-01-01

Purpose: This study investigates the calibration error of detector sensitivity for MapCheck due to inaccurate positioning of the device, which is not taken into account by the current commercial iterative calibration algorithm. We hypothesize the calibration is more vulnerable to the positioning error for the flatten filter free (FFF) beams than the conventional flatten filter flattened beams. Methods: MapCheck2 was calibrated with 10MV conventional and FFF beams, with careful alignment and with 1cm positioning error during calibration, respectively. Open fields of 37cmx37cm were delivered to gauge the impact of resultant calibration errors. The local calibration error was modeled as a detector independent multiplication factor, with which propagation error was estimated with positioning error from 1mm to 1cm. The calibrated sensitivities, without positioning error, were compared between the conventional and FFF beams to evaluate the dependence on the beam type. Results: The 1cm positioning error leads to 0.39% and 5.24% local calibration error in the conventional and FFF beams respectively. After propagating to the edges of MapCheck, the calibration errors become 6.5% and 57.7%, respectively. The propagation error increases almost linearly with respect to the positioning error. The difference of sensitivities between the conventional and FFF beams was small (0.11 ± 0.49%). Conclusion: The results demonstrate that the positioning error is not handled by the current commercial calibration algorithm of MapCheck. Particularly, the calibration errors for the FFF beams are ~9 times greater than those for the conventional beams with identical positioning error, and a small 1mm positioning error might lead to up to 8% calibration error. Since the sensitivities are only slightly dependent of the beam type and the conventional beam is less affected by the positioning error, it is advisable to cross-check the sensitivities between the conventional and FFF beams to detect

A Statistical Test of Correlations and Periodicities in the Geological Records

Science.gov (United States)

Yabushita, S.

1997-09-01

Matsumoto & Kubotani argued that there is a positive and statistically significant correlation between cratering and mass extinction. This argument is critically examined by adopting a method of Ertel used by Matsumoto & Kubotani but by applying it more directly to the extinction and cratering records. It is shown that on the null-hypothesis of random distribution of crater ages, the observed correlation has a probability of occurrence of 13%. However, when large craters are excluded whose ages agree with the times of peaks of extinction rate of marine fauna, one obtains a negative correlation. This result strongly indicates that mass extinction are not due to accumulation of impacts but due to isolated gigantic impacts.

Calculating statistical distributions from operator relations: The statistical distributions of various intermediate statistics

International Nuclear Information System (INIS)

Dai, Wu-Sheng; Xie, Mi

2013-01-01

In this paper, we give a general discussion on the calculation of the statistical distribution from a given operator relation of creation, annihilation, and number operators. Our result shows that as long as the relation between the number operator and the creation and annihilation operators can be expressed as a † b=Λ(N) or N=Λ −1 (a † b), where N, a † , and b denote the number, creation, and annihilation operators, i.e., N is a function of quadratic product of the creation and annihilation operators, the corresponding statistical distribution is the Gentile distribution, a statistical distribution in which the maximum occupation number is an arbitrary integer. As examples, we discuss the statistical distributions corresponding to various operator relations. In particular, besides the Bose–Einstein and Fermi–Dirac cases, we discuss the statistical distributions for various schemes of intermediate statistics, especially various q-deformation schemes. Our result shows that the statistical distributions corresponding to various q-deformation schemes are various Gentile distributions with different maximum occupation numbers which are determined by the deformation parameter q. This result shows that the results given in much literature on the q-deformation distribution are inaccurate or incomplete. -- Highlights: ► A general discussion on calculating statistical distribution from relations of creation, annihilation, and number operators. ► A systemic study on the statistical distributions corresponding to various q-deformation schemes. ► Arguing that many results of q-deformation distributions in literature are inaccurate or incomplete

Socioeconomic position and survival after lung cancer

DEFF Research Database (Denmark)

Dalton, Susanne O; Steding-Jessen, Marianne; Jakobsen, Erik

2015-01-01

BACKGROUND: To address social inequality in survival after lung cancer, it is important to consider how socioeconomic position (SEP) influences prognosis. We investigated whether SEP influenced receipt of first-line treatment and whether socioeconomic differences in survival could be explained...... by differences in stage, treatment and comorbidity. MATERIAL AND METHODS: In the Danish Lung Cancer Register, we identified 13 045 patients with lung cancer diagnosed in 2004-2010, with information on stage, histology, performance status and first-line treatment. We obtained age, gender, vital status, comorbid...... with stepwise inclusion of possible mediators. RESULTS: For both low- and high-stage lung cancer, adjusted ORs for first-line treatment were reduced in patients with short education and low income, although the OR for education did not reach statistical significance in men with high-stage disease. Patients...

Relationship between pre-extubation positive endexpiratory pressure and oxygenation after coronary artery bypass grafting

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Reijane Oliveira Lima

2015-08-01

Full Text Available Abstract Introduction After removal of endotracheal tube and artificial ventilation, ventilatory support should be continued, offering oxygen supply to ensure an arterial oxygen saturation close to physiological. Objective: The aim of this study was to investigate the effects of positive-end expiratory pressure before extubation on the oxygenation indices of patients undergoing coronary artery bypass grafting. Methods: A randomized clinical trial with seventy-eight patients undergoing coronary artery bypass grafting divided into three groups and ventilated with different positive-end expiratory pressure levels prior to extubation: Group A, 5 cmH2O (n=32; Group B, 8 cmH2O (n=26; and Group C, 10 cmH2O (n=20. Oxygenation index data were obtained from arterial blood gas samples collected at 1, 3, and 6 h after extubation. Patients with chronic pulmonary disease and those who underwent off-pump, emergency, or combined surgeries were excluded. For statistical analysis, we used Shapiro-Wilk, G, Kruskal-Wallis, and analysis of variance tests and set the level of significance at P<0.05. Results Groups were homogenous with regard to demographic, clinical, and surgical variables. There were no statistically significant differences between groups in the first 6 h after extubation with regard to oxygenation indices and oxygen therapy utilization. Conclusion: In this sample of patients undergoing coronary artery bypass grafting, the use of different positive-end expiratory pressure levels before extubation did not affect gas exchange or oxygen therapy utilization in the first 6 h after endotracheal tube removal.

Instrumented Impact Testing: Influence of Machine Variables and Specimen Position

International Nuclear Information System (INIS)

Lucon, E.; McCowan, C. N.; Santoyo, R. A.

2008-01-01

An investigation has been conducted on the influence of impact machine variables and specimen positioning on characteristic forces and absorbed energies from instrumented Charpy tests. Brittle and ductile fracture behavior has been investigated by testing NIST reference samples of low, high and super-high energy levels. Test machine variables included tightness of foundation, anvil and striker bolts, and the position of the center of percussion with respect to the center of strike. For specimen positioning, we tested samples which had been moved away or sideways with respect to the anvils. In order to assess the influence of the various factors, we compared mean values in the reference (unaltered) and altered conditions; for machine variables, t-test analyses were also performed in order to evaluate the statistical significance of the observed differences. Our results indicate that the only circumstance which resulted in variations larger than 5 percent for both brittle and ductile specimens is when the sample is not in contact with the anvils. These findings should be taken into account in future revisions of instrumented Charpy test standards.

Instrumented Impact Testing: Influence of Machine Variables and Specimen Position

Energy Technology Data Exchange (ETDEWEB)

Lucon, E.; McCowan, C. N.; Santoyo, R. A.

2008-09-15

An investigation has been conducted on the influence of impact machine variables and specimen positioning on characteristic forces and absorbed energies from instrumented Charpy tests. Brittle and ductile fracture behavior has been investigated by testing NIST reference samples of low, high and super-high energy levels. Test machine variables included tightness of foundation, anvil and striker bolts, and the position of the center of percussion with respect to the center of strike. For specimen positioning, we tested samples which had been moved away or sideways with respect to the anvils. In order to assess the influence of the various factors, we compared mean values in the reference (unaltered) and altered conditions; for machine variables, t-test analyses were also performed in order to evaluate the statistical significance of the observed differences. Our results indicate that the only circumstance which resulted in variations larger than 5 percent for both brittle and ductile specimens is when the sample is not in contact with the anvils. These findings should be taken into account in future revisions of instrumented Charpy test standards.

Statistical and theoretical research

International Nuclear Information System (INIS)

Anon.

1983-01-01

Significant accomplishments include the creation of field designs to detect population impacts, new census procedures for small mammals, and methods for designing studies to determine where and how much of a contaminant is extent over certain landscapes. A book describing these statistical methods is currently being written and will apply to a variety of environmental contaminants, including radionuclides. PNL scientists also have devised an analytical method for predicting the success of field eexperiments on wild populations. Two highlights of current research are the discoveries that population of free-roaming horse herds can double in four years and that grizzly bear populations may be substantially smaller than once thought. As stray horses become a public nuisance at DOE and other large Federal sites, it is important to determine their number. Similar statistical theory can be readily applied to other situations where wild animals are a problem of concern to other government agencies. Another book, on statistical aspects of radionuclide studies, is written specifically for researchers in radioecology

Clinical significance of plasma lysophosphatidic acid levels in the differential diagnosis of ovarian cancer

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Yun-Jie Zhang

2015-01-01

Full Text Available Objective: To investigate the value of lysophosphatidic acid (LPA in the diagnosis of ovarian cancer. Materials and Methods: We first performed a hospital-based, case-control study involving 123 ovarian cancer patients and 101 benign ovarian tumor patients, and then conducted a meta-analysis with 19 case-control studies to assess the correlation between ovarian cancer and plasma LPA levels. Results: The case-control study results demonstrated that ovarian cancer patients have increased LPA and cancer antigen (CA-125 levels compared to patients with benign ovarian tumor (LPA: Ovarian cancer vs benign ovarian tumor: 5.28 ± 1.52 vs 1.82 ± 0.77 μmol/L; CA-125: Ovarian cancer vs benign ovarian tumor: 87.17 ± 45.81 vs. 14.03 ± 10.14 U/mL, which showed statistically significant differences (both P < 0.05. LPA with advanced sensitivity, specificity, positive predictive value, negative predictive value, and accuracy rate of diagnosis excelled CA-125 in the diagnosis of ovarian cancer (both P < 0.05. The areas under the receiver operating characteristic (ROC curve in the diagnosis of ovarian cancer (LPA: 0.983; CA-125: 0.910 were statistically significant compared with the reference (both P < 0.001 and the difference of the areas of ROC curve between LPA and CA-125 in the diagnosis of ovarian cancer showed statistically significant difference (P < 0.05. The meta-analysis results suggested that plasma LPA levels were higher in ovarian cancer tissues than in benign tissues (standardized mean difference (SMD =2.36, 95% confidence interval (CI: 1.61-3.11, P < 0.001 and normal tissues (SMD = 2.32, 95% CI: 1.77-2.87, P < 0.001. Conclusion: LPA shows greater value in the diagnosis of ovarian cancer compared to CA-125 and may be employed as a biological index to diagnose ovarian cancer.

Significance analysis of lexical bias in microarray data

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Falkow Stanley

2003-04-01

Full Text Available Abstract Background Genes that are determined to be significantly differentially regulated in microarray analyses often appear to have functional commonalities, such as being components of the same biochemical pathway. This results in certain words being under- or overrepresented in the list of genes. Distinguishing between biologically meaningful trends and artifacts of annotation and analysis procedures is of the utmost importance, as only true biological trends are of interest for further experimentation. A number of sophisticated methods for identification of significant lexical trends are currently available, but these methods are generally too cumbersome for practical use by most microarray users. Results We have developed a tool, LACK, for calculating the statistical significance of apparent lexical bias in microarray datasets. The frequency of a user-specified list of search terms in a list of genes which are differentially regulated is assessed for statistical significance by comparison to randomly generated datasets. The simplicity of the input files and user interface targets the average microarray user who wishes to have a statistical measure of apparent lexical trends in analyzed datasets without the need for bioinformatics skills. The software is available as Perl source or a Windows executable. Conclusion We have used LACK in our laboratory to generate biological hypotheses based on our microarray data. We demonstrate the program's utility using an example in which we confirm significant upregulation of SPI-2 pathogenicity island of Salmonella enterica serovar Typhimurium by the cation chelator dipyridyl.

Whither Statistics Education Research?

Science.gov (United States)

Watson, Jane

2016-01-01

This year marks the 25th anniversary of the publication of a "National Statement on Mathematics for Australian Schools", which was the first curriculum statement this country had including "Chance and Data" as a significant component. It is hence an opportune time to survey the history of the related statistics education…

Clinical Significance of Immuno phenotypic Markers in Pediatric T-cell Acute Lymphoblastic Leukemia

International Nuclear Information System (INIS)

SIDHOM, I.; SHAABAN, Kh.; SOLIMAN, S.; HAMDY, N.; YASSIN, D.; SALEM, Sh.; HASSANEIN, H.; MANSOUR, M.T.; EZZAT, S.; EL-ANWAR, W.

2008-01-01

Background: Cell-marker profiling has led to conflicting conclusions about its prognostic significance in T-ALL. Aim: To investigate the prevalence of the expression of CD34, CD10 and myeloid associated antigens (CD13/ CD33) in childhood T-ALL and to relate their presence to initial clinical and biologic features and early response to therapy. Patients and Methods: This study included 67 consecutive patients with newly diagnosed T-ALL recruited from the Children's Cancer Hospital in Egypt during the time period from July 2007 to June 2008. Immuno phenotypic markers and minimal residual disease (MRD) were studied by five-color flow cytometry. Results: The frequency of CD34 was 34.9%, CD10 33.3%, while CD13/CD33 was 18.8%. No significant association was encountered between CD34, CD10 or myeloid antigen positivity and the presenting clinical features as age, sex, TLC and CNS leukemia. Only CD10+ expression had significant association with initial CNS involvement (p=0.039). CD34 and CD13/CD33 expression was significantly associated with T-cell maturation stages (p<0.05). No relationship was observed for age, TLC, gender, NCI risk or CNS involvement with early response to therapy illustrated by BM as well as MRD day 15 and day 42. CD34+, CD13/CD33+ and early T-cell stage had high MRD levels on day 15 that was statistically highly significant (p<0.01), but CD10+ had statistically significant lower MRD level on day 15 (p=0.049). However, only CD34 retained its significance at an MRD cut-off level of 0.01%. Conclusion: CD34, CD10, CD13/CD33 expression, as well as T-cell maturation stages, may have prognostic significance in pediatric T-ALL as they have a significant impact on early clearance of leukemic cells detected by MRD day 15.

Applications of quantum entropy to statistics

International Nuclear Information System (INIS)

Silver, R.N.; Martz, H.F.

1994-01-01

This paper develops two generalizations of the maximum entropy (ME) principle. First, Shannon classical entropy is replaced by von Neumann quantum entropy to yield a broader class of information divergences (or penalty functions) for statistics applications. Negative relative quantum entropy enforces convexity, positivity, non-local extensivity and prior correlations such as smoothness. This enables the extension of ME methods from their traditional domain of ill-posed in-verse problems to new applications such as non-parametric density estimation. Second, given a choice of information divergence, a combination of ME and Bayes rule is used to assign both prior and posterior probabilities. Hyperparameters are interpreted as Lagrange multipliers enforcing constraints. Conservation principles are proposed to act statistical regularization and other hyperparameters, such as conservation of information and smoothness. ME provides an alternative to heirarchical Bayes methods

Statistical inference from imperfect photon detection

International Nuclear Information System (INIS)

Audenaert, Koenraad M R; Scheel, Stefan

2009-01-01

We consider the statistical properties of photon detection with imperfect detectors that exhibit dark counts and less than unit efficiency, in the context of tomographic reconstruction. In this context, the detectors are used to implement certain positive operator-valued measures (POVMs) that would allow us to reconstruct the quantum state or quantum process under consideration. Here we look at the intermediate step of inferring outcome probabilities from measured outcome frequencies, and show how this inference can be performed in a statistically sound way in the presence of detector imperfections. Merging outcome probabilities for different sets of POVMs into a consistent quantum state picture has been treated elsewhere (Audenaert and Scheel 2009 New J. Phys. 11 023028). Single-photon pulsed measurements as well as continuous wave measurements are covered.

Statistics

CERN Document Server

Hayslett, H T

1991-01-01

Statistics covers the basic principles of Statistics. The book starts by tackling the importance and the two kinds of statistics; the presentation of sample data; the definition, illustration and explanation of several measures of location; and the measures of variation. The text then discusses elementary probability, the normal distribution and the normal approximation to the binomial. Testing of statistical hypotheses and tests of hypotheses about the theoretical proportion of successes in a binomial population and about the theoretical mean of a normal population are explained. The text the

The clinical significance of serum SCC-Ag combined with CD105 in patients with cervical cancer during the early stage diagnosis

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Ru-Chan Ma

2016-09-01

Full Text Available Objective: To invest the clinical significance of serum SCC-Ag combined with CD105 in early diagnosis of cervical cancer to provide new ideas for early diagnosis and clinical treatment of cervical cancer. Methods: A total of 74 cases cervical cancer patients were selected as cervical cancer group, and 52 cases uterine fibroids patients were selected as normal cervical group, serum samples were collected in the early morning fasting condition, SCC-Ag and CD105 were checked by ELISA method, SCC-Ag and CD105 of two groups were analyzed by t-test, and to compare SCC-Ag and CD105 in different TMN staging, lymph gland metastasis and non-lymph gland metastasis in patients with cervical cancer, the correlation analysis was used by Pearson correlation analysis method. Results: These results came from ELISA method, comparing with normal cervical group, the SCC-Ag and CD105 of cervical cancer group increased, the difference was statistically significant. Comparing with Ⅰ period of TMN staging, SCC-Ag and CD105 of Ⅱ period increased, Ⅲ, Ⅳ period increased, the difference was statistically significant. Comparing with Ⅱ period, SCC-Ag and CD105 of Ⅲ, Ⅳ period increased, the difference was statistically significant. Comparing with non-lymph gland metastasis, SCC-Ag and CD105 of lymph gland metastasis increased in cervical cancer with surgical treatment, the difference was statistically significant. According to Pearson correlation analysis, SCC-Ag and CD105 were positively correlated. Conclusion: SCC-Ag and CD105 in patients with cervical cancer increase highly, it has important clinical value that of serum SCCAg combined with CD105 in the early diagnosis of cervical cancer, especially it has clinical guiding significance to staging and lymph gland metastasis of cervical cancer, and it is worthy of clinical reference.

New scanning technique using Adaptive Statistical Iterative Reconstruction (ASIR) significantly reduced the radiation dose of cardiac CT.

Science.gov (United States)

Tumur, Odgerel; Soon, Kean; Brown, Fraser; Mykytowycz, Marcus

2013-06-01

The aims of our study were to evaluate the effect of application of Adaptive Statistical Iterative Reconstruction (ASIR) algorithm on the radiation dose of coronary computed tomography angiography (CCTA) and its effects on image quality of CCTA and to evaluate the effects of various patient and CT scanning factors on the radiation dose of CCTA. This was a retrospective study that included 347 consecutive patients who underwent CCTA at a tertiary university teaching hospital between 1 July 2009 and 20 September 2011. Analysis was performed comparing patient demographics, scan characteristics, radiation dose and image quality in two groups of patients in whom conventional Filtered Back Projection (FBP) or ASIR was used for image reconstruction. There were 238 patients in the FBP group and 109 patients in the ASIR group. There was no difference between the groups in the use of prospective gating, scan length or tube voltage. In ASIR group, significantly lower tube current was used compared with FBP group, 550 mA (450-600) vs. 650 mA (500-711.25) (median (interquartile range)), respectively, P ASIR group compared with FBP group, 4.29 mSv (2.84-6.02) vs. 5.84 mSv (3.88-8.39) (median (interquartile range)), respectively, P ASIR was associated with increased image noise compared with FBP (39.93 ± 10.22 vs. 37.63 ± 18.79 (mean ± standard deviation), respectively, P ASIR reduces the radiation dose of CCTA without affecting the image quality. © 2013 The Authors. Journal of Medical Imaging and Radiation Oncology © 2013 The Royal Australian and New Zealand College of Radiologists.

Positive Disposition in the Prediction of Strategic Independence among Millennials

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Robert Konopaske

2017-11-01

Full Text Available Research on the dispositional traits of Millennials (born in 1980–2000 finds that this generation, compared to earlier generations, tends to be more narcissistic, hold themselves in higher regard and feel more entitled to rewards. The purpose of this intragenerational study is to counter balance extant research by exploring how the positive dispositional traits of proactive personality, core self-evaluation, grit and self-control predict strategic independence in a sample of 311 young adults. Strategic independence is a composite variable measuring a person’s tendency to make plans and achieve long-term goals. A confirmatory factor analysis and hierarchical regression found evidence of discriminant validity across the scales and that three of the four independent variables were statistically significant and positive predictors of strategic independence in the study. The paper discusses research and practical implications, strengths and limitations and areas for future research.

Clinical Significance of Tumor Marker Detection in Patients 
with Advanced Squamous Cell Carcimoma of the Lung

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Ping LIANG

2016-10-01

Full Text Available Background and objective Due to it's concealment and no obvious symptoms, lung squamous carcimoma often has advanced disease when diagnosed. The aims of this study were to describe the characteristics of the disease, to evaluate the clinical importance of detection of multiple tumor markers in patients with squamous cell carcinoma of the lung. Methods The characteristics of all patients with advanced squamous cell lung cancer treated in Beijing Cancer Hospital of Chinese Academy of Medical Sciences during Jan. 2011 to Dec. 2015 were identified by cases reviewing and data extracting. The characteristics, detection levels and sensitivity of multiple tumor makers among patients were described. Results The 260 patients were treated with mean age of (59.4±9.2 years, 85.8% (n=223 of them were male, 14.2% (n=37 of them were female. 78.1% (n=203 of all were smokers and 3.1% (n=8 of patients had family history of tumor. The positive rate of cytokerantin 19 fragment (CYFRA21-1 was 71.2%, which was the highest among five tumor markers. The five tumor markers median level had no statistical significance between different tumor (T stages and node (N stages (all P>0.05, only the positive rate of SCC had statistical significance between different T stages (P=0.035. The combination measurement of CYFRA21-1+carcinogen-embryonic antigen (CEA, CYFRA21-1+CEA+cancer antigen (CA125, CA125+CYFRA21-1+CEA+neuron specific enolase (NSE, and CA125+CYFRA21-1+NSE+CEA+squamous cell carcinoma antigen (SCC were better and had higher clinical values, the positive rates were 82.7%, 84.6%, 85.0% and 86.2%, respectively. Conclusion The positive rate of CYFRA21-1 was the highest and the sensitivity of single test of five tumor markers was low, the combination of multiple tumor markers increased the sensitivity of diagnosis of SQCLC, the combination of CA125, CYFRA21-1 and CEA was the best choice.

Positive-Operator Valued Measure (POVM Quantization

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Jean Pierre Gazeau

2014-12-01

Full Text Available We present a general formalism for giving a measure space paired with a separable Hilbert space a quantum version based on a normalized positive operator-valued measure. The latter are built from families of density operators labeled by points of the measure space. We especially focus on various probabilistic aspects of these constructions. Simple ormore elaborate examples illustrate the procedure: circle, two-sphere, plane and half-plane. Links with Positive-Operator Valued Measure (POVM quantum measurement and quantum statistical inference are sketched.

Industrial commodity statistics yearbook 2001. Production statistics (1992-2001)

International Nuclear Information System (INIS)

2003-01-01

This is the thirty-fifth in a series of annual compilations of statistics on world industry designed to meet both the general demand for information of this kind and the special requirements of the United Nations and related international bodies. Beginning with the 1992 edition, the title of the publication was changed to industrial Commodity Statistics Yearbook as the result of a decision made by the United Nations Statistical Commission at its twenty-seventh session to discontinue, effective 1994, publication of the Industrial Statistics Yearbook, volume I, General Industrial Statistics by the Statistics Division of the United Nations. The United Nations Industrial Development Organization (UNIDO) has become responsible for the collection and dissemination of general industrial statistics while the Statistics Division of the United Nations continues to be responsible for industrial commodity production statistics. The previous title, Industrial Statistics Yearbook, volume II, Commodity Production Statistics, was introduced in the 1982 edition. The first seven editions in this series were published under the title The Growth of World industry and the next eight editions under the title Yearbook of Industrial Statistics. This edition of the Yearbook contains annual quantity data on production of industrial commodities by country, geographical region, economic grouping and for the world. A standard list of about 530 commodities (about 590 statistical series) has been adopted for the publication. The statistics refer to the ten-year period 1992-2001 for about 200 countries and areas

Industrial commodity statistics yearbook 2002. Production statistics (1993-2002)

International Nuclear Information System (INIS)

2004-01-01

This is the thirty-sixth in a series of annual compilations of statistics on world industry designed to meet both the general demand for information of this kind and the special requirements of the United Nations and related international bodies. Beginning with the 1992 edition, the title of the publication was changed to industrial Commodity Statistics Yearbook as the result of a decision made by the United Nations Statistical Commission at its twenty-seventh session to discontinue, effective 1994, publication of the Industrial Statistics Yearbook, volume I, General Industrial Statistics by the Statistics Division of the United Nations. The United Nations Industrial Development Organization (UNIDO) has become responsible for the collection and dissemination of general industrial statistics while the Statistics Division of the United Nations continues to be responsible for industrial commodity production statistics. The previous title, Industrial Statistics Yearbook, volume II, Commodity Production Statistics, was introduced in the 1982 edition. The first seven editions in this series were published under the title 'The Growth of World industry' and the next eight editions under the title 'Yearbook of Industrial Statistics'. This edition of the Yearbook contains annual quantity data on production of industrial commodities by country, geographical region, economic grouping and for the world. A standard list of about 530 commodities (about 590 statistical series) has been adopted for the publication. The statistics refer to the ten-year period 1993-2002 for about 200 countries and areas

Industrial commodity statistics yearbook 2000. Production statistics (1991-2000)

International Nuclear Information System (INIS)

2002-01-01

This is the thirty-third in a series of annual compilations of statistics on world industry designed to meet both the general demand for information of this kind and the special requirements of the United Nations and related international bodies. Beginning with the 1992 edition, the title of the publication was changed to industrial Commodity Statistics Yearbook as the result of a decision made by the United Nations Statistical Commission at its twenty-seventh session to discontinue, effective 1994, publication of the Industrial Statistics Yearbook, volume I, General Industrial Statistics by the Statistics Division of the United Nations. The United Nations Industrial Development Organization (UNIDO) has become responsible for the collection and dissemination of general industrial statistics while the Statistics Division of the United Nations continues to be responsible for industrial commodity production statistics. The previous title, Industrial Statistics Yearbook, volume II, Commodity Production Statistics, was introduced in the 1982 edition. The first seven editions in this series were published under the title The Growth of World industry and the next eight editions under the title Yearbook of Industrial Statistics. This edition of the Yearbook contains annual quantity data on production of industrial commodities by country, geographical region, economic grouping and for the world. A standard list of about 530 commodities (about 590 statistical series) has been adopted for the publication. Most of the statistics refer to the ten-year period 1991-2000 for about 200 countries and areas

Comparing Knee Joint Position Sense in Patellofemoral Pain and Healthy Futsal Women

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Negar Kooroshfar

2017-03-01

Full Text Available Background: Proprioception, or joint position sense, probably plays an important role in joint function. A number of studies have shown that proper joint position sense can decrease the risk of injuries in sports. It is not very clear how patellofemoral pain syndrome (PFPS can affect athletes joint position sense (JPS. Regarding the importance of proper joint position sense for movement performance and injury prevention in athletes, the aim of this study was to evaluate knee JPS in athletes with PFPS and compare it with asymptomatic individuals under non-weight bearing (sitting conditions. Methods: The study design was comparative in which 15 patients and 15 healthy athletes participated. JPS was evaluated by active and passive replication of knee angles for 30, 45 and 60° of knee flexion target angle while visual cues were eliminated. Each test was repeated three times. By subtracting the test angle from the replicated angle, the absolute error was calculated as a dependent variable. T-statistical test was used to compare data between two groups and P value of 0.05 was considered as the level of statistical significance. Results: No significant difference (P<0.05 in active (A and passive (P knee JPS was found between two groups for three (30°, p-value (A =0.79, P=0.68, 45°, P value (A=0.12, P=0.54 and 60°, P value (A=0.74, P=0.71 target angles. Conclusion: According to results, both groups had the same JPS ability, it seems PFPS does not affect the knee JPS at least in athlete cases. It would be possible that deficiency of JPS compensated for the physical activity or on the other hand, maybe pain intensity was not high enough to interfere with JPS accuracy. According to our results, PFPS doesn’t reduce IPS but further investigation is needed to disclose if other factors such as skill

Macro-indicators of citation impacts of six prolific countries: InCites data and the statistical significance of trends.

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Lutz Bornmann

Full Text Available Using the InCites tool of Thomson Reuters, this study compares normalized citation impact values calculated for China, Japan, France, Germany, United States, and the UK throughout the time period from 1981 to 2010. InCites offers a unique opportunity to study the normalized citation impacts of countries using (i a long publication window (1981 to 2010, (ii a differentiation in (broad or more narrow subject areas, and (iii allowing for the use of statistical procedures in order to obtain an insightful investigation of national citation trends across the years. Using four broad categories, our results show significantly increasing trends in citation impact values for France, the UK, and especially Germany across the last thirty years in all areas. The citation impact of papers from China is still at a relatively low level (mostly below the world average, but the country follows an increasing trend line. The USA exhibits a stable pattern of high citation impact values across the years. With small impact differences between the publication years, the US trend is increasing in engineering and technology but decreasing in medical and health sciences as well as in agricultural sciences. Similar to the USA, Japan follows increasing as well as decreasing trends in different subject areas, but the variability across the years is small. In most of the years, papers from Japan perform below or approximately at the world average in each subject area.

Intraoperative and postoperative evaluation of low tidal volume combined with low-level positive end-expiratory pressure ventilation in laparoscopic surgery in elderly patients

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Ye-Qiu Li

2016-01-01

Full Text Available Objective: To evaluate intraoperative and postoperative condition of low tidal volume combined with low-level positive end-expiratory pressure ventilation in laparoscopic surgery in elderly patients. Methods: A total of 176 cases of elderly patients (more than 60 years old receiving laparoscopic surgery in our hospital from July 2013 to July 2015 were selected as research subjects and randomly divided into observation group and control group, each group included 88 cases, control group received conventional ventilation strategy, observation group received low tidal volume combined with low-level positive end-expiratory pressure ventilation strategy, and then levels of hemodynamic indexes, respiratory mechanical indexes, serology indexes and cerebral vessel related indexes, etc of two groups were compared. Results: Intraoperative and postoperative heart rate and mean arterial pressure levels of observation group were lower than those of control group, arterial partial pressure of oxygen and oxygenation index levels were higher than those of control group and differences had statistical significance (P<0.05; intraoperative APIP and Pplat values of observation group were lower than those of control group, Cs value was higher than that of control group and differences had statistical significance (P<0.05; intraoperative and postoperative serum IL-8 and TNF-α levels of observation group were lower than those of control group, IL-10 level was higher than that of control group and differences had statistical significance (P<0.05; intraoperative and postoperative PjvO2, SjvO2 and CjvO2 levels of observation group were higher than those of control group, Da-jvO2 level was lower than that of control group and differences had statistical significance (P<0.05. Conclusions: When elderly patients receive laparoscopic surgery, the use of low tidal volume combined with low-level positive end-expiratory pressure ventilation strategy can stabilize hemodynamic

Infant Positioning, Baby Gear Use, and Cranial Asymmetry.

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Zachry, Anne H; Nolan, Vikki G; Hand, Sarah B; Klemm, Susan A

2017-12-01

Objectives This study aimed to identify predictors of cranial asymmetry. We hypothesize that among infants diagnosed with cranial asymmetry in the sampled region, there is an association between exposure to more time in baby gear and less awake time in prone and side-lying than in infants who do not present with this condition. Methods The study employed a cross sectional survey of caregivers of typically developing infants and infants diagnosed with cranial asymmetry. Results A mutivariable model reveals that caregivers of children who are diagnosed with cranial asymmetry report their children spending significantly less time in prone play than those children without a diagnosis of cranial asymmetry. Side-lying and time spent in baby gear did not attain statistical significance. Conclusions for Practice Occupational therapists, physical therapists, pediatricians, nurses and other health care professionals must provide parents with early education about the importance of varying positions and prone play in infancy and address fears and concerns that may serve as barriers to providing prone playtime.

Methodological Problems Of Statistical Study Of Regional Tourism And Tourist Expenditure

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Anton Olegovich Ovcharov

2015-03-01

Full Text Available The aim of the work is the analysis of the problems of regional tourism statistics. The subject of the research is the tourism expenditure, the specificity of their recording and modeling. The methods of statistical observation and factor analysis are used. The article shows the features and directions of statistical methodology of tourism. A brief review of international publications on statistical studies of tourist expenditure is made. It summarizes the data from different statistical forms and shows the positive and negative trends in the development of tourism in Russia. It is concluded that the tourist industry in Russia is focused on outbound tourism rather than on inbound or internal. The features of statistical accounting and statistical analysis of tourism expenditure in Russian and international statistics are described. To assess the level of development of regional tourism the necessity of use the coefficient of efficiency of tourism. The reasons of the prevalence of imports over exports of tourism services are revealed using the data of the balance of payments. This is due to the raw material orientation of Russian exports and low specific weight of the account “Services” in the structure of the balance of payments. The additive model is also proposed in the paper. It describes the influence of three factors on the changes in tourist expenditure. These factors are the number of trips, the cost of a trip and structural changes in destinations and travel purposes. On the basis of the data from 2012–2013 we estimate the force and the direction of the influence of each factor. Testing of the model showed that the increase in tourism exports caused by the combined positive impact of all three factors, chief of which is the growing number of foreigners who visited Russia during the concerned period.

Enhancing pediatric clinical trial feasibility through the use of Bayesian statistics.

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Huff, Robin A; Maca, Jeff D; Puri, Mala; Seltzer, Earl W

2017-11-01

BackgroundPediatric clinical trials commonly experience recruitment challenges including limited number of patients and investigators, inclusion/exclusion criteria that further reduce the patient pool, and a competitive research landscape created by pediatric regulatory commitments. To overcome these challenges, innovative approaches are needed.MethodsThis article explores the use of Bayesian statistics to improve pediatric trial feasibility, using pediatric Type-2 diabetes as an example. Data for six therapies approved for adults were used to perform simulations to determine the impact on pediatric trial size.ResultsWhen the number of adult patients contributing to the simulation was assumed to be the same as the number of patients to be enrolled in the pediatric trial, the pediatric trial size was reduced by 75-78% when compared with a frequentist statistical approach, but was associated with a 34-45% false-positive rate. In subsequent simulations, greater control was exerted over the false-positive rate by decreasing the contribution of the adult data. A 30-33% reduction in trial size was achieved when false-positives were held to less than 10%.ConclusionReducing the trial size through the use of Bayesian statistics would facilitate completion of pediatric trials, enabling drugs to be labeled appropriately for children.

Enrichment of statistical power for genome-wide association studies

Science.gov (United States)

The inheritance of most human diseases and agriculturally important traits is controlled by many genes with small effects. Identifying these genes, while simultaneously controlling false positives, is challenging. Among available statistical methods, the mixed linear model (MLM) has been the most fl...

Childhood-compared to adolescent-onset bipolar disorder has more statistically significant clinical correlates.

Science.gov (United States)

Holtzman, Jessica N; Miller, Shefali; Hooshmand, Farnaz; Wang, Po W; Chang, Kiki D; Hill, Shelley J; Rasgon, Natalie L; Ketter, Terence A

2015-07-01

The strengths and limitations of considering childhood-and adolescent-onset bipolar disorder (BD) separately versus together remain to be established. We assessed this issue. BD patients referred to the Stanford Bipolar Disorder Clinic during 2000-2011 were assessed with the Systematic Treatment Enhancement Program for BD Affective Disorders Evaluation. Patients with childhood- and adolescent-onset were compared to those with adult-onset for 7 unfavorable bipolar illness characteristics with replicated associations with early-onset patients. Among 502 BD outpatients, those with childhood- (adolescent- (13-18 years, N=218) onset had significantly higher rates for 4/7 unfavorable illness characteristics, including lifetime comorbid anxiety disorder, at least ten lifetime mood episodes, lifetime alcohol use disorder, and prior suicide attempt, than those with adult-onset (>18 years, N=174). Childhood- but not adolescent-onset BD patients also had significantly higher rates of first-degree relative with mood disorder, lifetime substance use disorder, and rapid cycling in the prior year. Patients with pooled childhood/adolescent - compared to adult-onset had significantly higher rates for 5/7 of these unfavorable illness characteristics, while patients with childhood- compared to adolescent-onset had significantly higher rates for 4/7 of these unfavorable illness characteristics. Caucasian, insured, suburban, low substance abuse, American specialty clinic-referred sample limits generalizability. Onset age is based on retrospective recall. Childhood- compared to adolescent-onset BD was more robustly related to unfavorable bipolar illness characteristics, so pooling these groups attenuated such relationships. Further study is warranted to determine the extent to which adolescent-onset BD represents an intermediate phenotype between childhood- and adult-onset BD. Copyright © 2015 Elsevier B.V. All rights reserved.

Small Intestinal Bacterial Overgrowth May Increase the Likelihood of Lactose and Sorbitol but not Fructose Intolerance False Positive Diagnosis.

Science.gov (United States)

Perets, Tsachi Tsadok; Hamouda, Dalal; Layfer, Olga; Ashorov, Olga; Boltin, Doron; Levy, Sigal; Niv, Yaron; Dickman, Ram

2017-08-01

Small intestinal bacterial overgrowth (SIBO) is defined as a bacterial count of more than 10 5 colony-forming units per milliliter in duodenal aspirate. It shares many symptoms with carbohydrate intolerance, which makes the clinical distinction of the disorders difficult. The aim of the study was to examine the relationship between a positive carbohydrate breath test and the presence of SIBO suggested by a positive lactulose hydrogen breath test. The electronic database of the gastroenterology laboratory of a tertiary medical center was searched for all patients clinically tested for SIBO in 2012-2013 for whom previous results for lactose, fructose, and/or sorbitol breath test were available. The correlation between positive findings for carbohydrate intolerance and for SIBO was statistically analyzed. The study group included 349 patients, 231 female and 118 male, of mean age 53±19 years. All had symptoms of abdominal bloating and gas. There was a statistically significant difference in rates of a positive breath test for lactose and sorbitol at ≤90 minutes between patients who were positive and negative for SIBO [χ 2 (1)=12.8, p <0.01 and χ 2 (1)=9.5, p <0.01 respectively]. Findings for fructose were not significant. There was no effect of age or gender. SIBO may represent an important reversible cause of carbohydrate intolerance. It may be especially prudent to exclude SIBO patients with an early peak (≤90 minutes) in H 2 excretion. © 2017 by the Association of Clinical Scientists, Inc.

Implementation of International Standards in Russia's Foreign Trade Statistics

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Natalia E. Grigoruk

2015-01-01

Full Text Available The article analyzes the basic documents of international organizations in recent years, which have become the global standard for the development and improvement of statistics of foreign economic relations of most countries, including the Russian Federation. The article describes the key features of the theory and practice of modern foreign trade statistics in Russia and abroad, with an emphasis on the methodological problems of its main parts - the external trade statistics. It shows their interpretation in the most recent recommendations by UN statistical apparatus and other international organizations; considers a range of problems associated with the implementation of the national statistical practices of countries, including Russia and the countries of the Customs Union, the main international standard of foreign trade statistics - UN document "International Merchandise Trade Statistics". The main attention is paid to methodological issues such as: the criteria for selecting the objects of statistical accounting in accordance with international standards, quantitative and cost parameters of foreign trade statistics, statistical methods and estimates of commodity exports and imports, the problems of comparability of data; to a comparison of international standards in 2010 with documents on key precursor methodology of foreign trade statistics, characterized by the practice of introducing these standards in the foreign trade statistics of Russia and the countries of the Customs Union. The article analyzes the content given in the official statistical manuals of Russia foreign trade and foreign countries, covers the main methodological problems of World Trade in conjunction with the major current international statistical standards - System of National Accounts, Manual on Statistics of International Trade in Services and other documents; provides specific data describing the current structure of Russian foreign trade and especially its

Encounter Probability of Significant Wave Height

DEFF Research Database (Denmark)

Liu, Z.; Burcharth, H. F.

The determination of the design wave height (often given as the significant wave height) is usually based on statistical analysis of long-term extreme wave height measurement or hindcast. The result of such extreme wave height analysis is often given as the design wave height corresponding to a c...

Error Analysis of Determining Airplane Location by Global Positioning System

OpenAIRE

Hajiyev, Chingiz; Burat, Alper

1999-01-01

This paper studies the error analysis of determining airplane location by global positioning system (GPS) using statistical testing method. The Newton Rhapson method positions the airplane at the intersection point of four spheres. Absolute errors, relative errors and standard deviation have been calculated The results show that the positioning error of the airplane varies with the coordinates of GPS satellite and the airplane.

The influence of somatotype components and personality traits on the playing position and the quality of top Croatian female cadet handball players.

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Cavala, Marijana; Trninić, Viktorija; Jasić, Dajana; Tomljanović, Mario

2013-05-01

The research was conducted with the aim to establish the structure and the differences of morphological features and personality traits between different age groups of female cadet handball players grouped by their playing quality and playing positions. Further on, the research was done on 70 handball players aged 15, 31 on average, who were grouped according to their positions on goalkeepers, outside players, wings and pivots. Furthermore, according to the quality of playing, they were divided in two quality groups of players, those from the wider cadet national team, thus characterised as top female players in Croatia, and those who had never been invited into the cadet national team and thus can be referred to as low-quality, i.e. average female handball players. The structure of predictor variables has indicated the existence of general morphological factor assessing the players' constitution and two personality features factors - neuroticism and extraversion. The variance analysis showed no statistically significant differences of somatotype variables with relation to quality and playing position. By observing basic personality traits, a statistically significant difference was confirmed only in introversion-extraversion with a lower score in goalkeepers than in other positions, which indicates a higher level of introversion in this playing position. Such result was expected since this particular position abounds in specific tasks and demands in the game in relation to all other playing positions. Further on, it has been concluded that the selection of players must not be based only on the stated physical and psychological characteristics, but on relevant anthropological complexes determining performance and sport achievement.

Evaluation of the accuracy of linear and angular measurements on panoramic radiographs taken at different positions

Energy Technology Data Exchange (ETDEWEB)

Nikneshan, Sima; Emadi, Naghmeh [Dept. of Oral and Maxillofacial Radiology, Dental School, Shahid Beheshti University of Medical Sciences, Tehran (Iran, Islamic Republic of); Sharafi, Mohamad [Dept. of Oral and Maxillofacial Radiology, Dental School, Ilam University of Medical Sciences, Ilam (Iran, Islamic Republic of)

2013-09-15

This study assessed the accuracy of linear and angular measurements on panoramic radiographs taken at different positions in vitro. Two acrylic models were fabricated from a cast with normal occlusion. Straight and 75 degree mesially and lingually angulated pins were placed, and standardized panoramic radiographs were taken at standard position, at an 8 degree downward tilt of the occlusal plane compared to the standard position, at an 8 degree upward tilt of the anterior occlusal plane, and at a 10 degree downward tilt of the right and left sides of the model. On the radiographs, the length of the pins above (crown) and below (root) the occlusal plane, total pin length, crown-to-root ratio, and angulation of pins relative to the occlusal plane were calculated. The data were subjected to repeated measures ANOVA and LSD multiple comparisons tests. Significant differences were noted between the radiographic measurements and true values in different positions on both models with linear (P<0.001) and those with angulated pins (P<0.005). No statistically significant differences were observed between the angular measurements and baselines of the natural head posture at different positions for the linear and angulated pins. Angular measurements on panoramic radiographs were sufficiently accurate and changes in the position of the occlusal plane equal to or less than 10 degree had no significant effect on them. Some variations could exist in the pin positioning (head positioning), and they were tolerable while taking panoramic radiographs. Linear measurements showed the least errors in the standard position and 8 degree upward tilt of the anterior part of the occlusal plane compared to other positions.

Automatic generation of statistical pose and shape models for articulated joints.

Science.gov (United States)

Xin Chen; Graham, Jim; Hutchinson, Charles; Muir, Lindsay

2014-02-01

Statistical analysis of motion patterns of body joints is potentially useful for detecting and quantifying pathologies. However, building a statistical motion model across different subjects remains a challenging task, especially for a complex joint like the wrist. We present a novel framework for simultaneous registration and segmentation of multiple 3-D (CT or MR) volumes of different subjects at various articulated positions. The framework starts with a pose model generated from 3-D volumes captured at different articulated positions of a single subject (template). This initial pose model is used to register the template volume to image volumes from new subjects. During this process, the Grow-Cut algorithm is used in an iterative refinement of the segmentation of the bone along with the pose parameters. As each new subject is registered and segmented, the pose model is updated, improving the accuracy of successive registrations. We applied the algorithm to CT images of the wrist from 25 subjects, each at five different wrist positions and demonstrated that it performed robustly and accurately. More importantly, the resulting segmentations allowed a statistical pose model of the carpal bones to be generated automatically without interaction. The evaluation results show that our proposed framework achieved accurate registration with an average mean target registration error of 0.34 ±0.27 mm. The automatic segmentation results also show high consistency with the ground truth obtained semi-automatically. Furthermore, we demonstrated the capability of the resulting statistical pose and shape models by using them to generate a measurement tool for scaphoid-lunate dissociation diagnosis, which achieved 90% sensitivity and specificity.

Randomized controlled trial comparing nasal intermittent positive pressure ventilation and nasal continuous positive airway pressure in premature infants after tracheal extubation

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Daniela Franco Rizzo Komatsu

Full Text Available Summary Objective: To analyze the frequency of extubation failure in premature infants using conventional mechanical ventilation (MV after extubation in groups subjected to nasal intermittent positive pressure ventilation (nIPPV and continuous positive airway pressure (nCPAP. Method: Seventy-two premature infants with respiratory failure were studied, with a gestational age (GA ≤ 36 weeks and birth weight (BW > 750 g, who required tracheal intubation and mechanical ventilation. The study was controlled and randomized in order to ensure that the members of the groups used in the research were chosen at random. Randomization was performed at the time of extubation using sealed envelopes. Extubation failure was defined as the need for re-intubation and mechanical ventilation during the first 72 hours after extubation. Results: Among the 36 premature infants randomized to nIPPV, six (16.6% presented extubation failure in comparison to 11 (30.5% of the 36 premature infants randomized to nCPAP. There was no statistical difference between the two study groups regarding BW, GA, classification of the premature infant, and MV time. The main cause of extubation failure was the occurrence of apnea. Gastrointestinal and neurological complications did not occur in the premature infants participating in the study. Conclusion: We found that, despite the extubation failure of the group of premature infants submitted to nIPPV being numerically smaller than in premature infants submitted to nCPAP, there was no statistically significant difference between the two modes of ventilatory support after extubation.

Body indices and basic vital signs in Helicobacter pylori positive and negative persons

International Nuclear Information System (INIS)

Kopacova, Marcela; Bures, Jan; Koupil, Ilona; Rejchrt, Stanislav; Vorisek, Viktor; Seifert, Bohumil; Pozler, Oldrich; Zivny, Pavel; Douda, Tomas; Palicka, Vladimir; Holcik, Jan

2007-01-01

It has been hypothesized that Helicobacter pylori (Hp) infection may contribute to reduced stature, risk of hypertension or obesity. The aim was to evaluate body indices in Hp positive and negative persons. A total of 2436 subjects (4-100 years old) were tested for Hp status by 13 C-urea breath test. Data on height and weight were collected for 84%, and blood pressure for 80% of the study subjects. The prevalence of Hp infection was 41.6%. The odds ratio for a 10-year increase in age was 1.21 (95% CI 1.17-1.25, p-value <0.001). Statistically significant negative association of Hp positivity with body height was most pronounced in the younger age groups, while a positive association of Hp positivity with body mass index was only seen in those aged 15+ years. There was a negative effect of Hp positivity on systolic and diastolic blood pressure in subjects below 25 and a relatively strong positive effect on blood pressure in subjects over 65 years. Residual confounding by social characteristics as a possible explanation for the associations of Hp positivity with height and blood pressure cannot be excluded. Unmeasured factors related to social and family environment may cause the apparent association between Hp positivity and children's growth and blood pressure

Higher positive identification of malignant CSF cells using the cytocentrifuge than the Suta chamber

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Sérgio Monteiro de Almeida

Full Text Available ABSTRACT Objective To define how to best handle cerebrospinal fluid (CSF specimens to obtain the highest positivity rate for the diagnosis of malignancy, comparing two different methods of cell concentration, sedimentation and cytocentrifugation. Methods A retrospective analysis of 411 CSF reports. Results This is a descriptive comparative study. The positive identification of malignant CSF cells was higher using the centrifuge than that using the Suta chamber (27.8% vs. 19.0%, respectively; p = 0.038. Centrifuge positively identified higher numbers of malignant cells in samples with a normal concentration of white blood cells (WBCs (< 5 cells/mm3 and with more than 200 cells/mm3, although this was not statistically significant. There was no lymphocyte loss using either method. Conclusions Cytocentrifugation positively identified a greater number of malignant cells in the CSF than cytosedimentation with the Suta chamber. However, there was no difference between the methods when the WBC counts were within the normal range.

A Clustered Randomized Controlled Trial of the Positive Prevention PLUS Adolescent Pregnancy Prevention Program.

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LaChausse, Robert G

2016-09-01

To determine the impact of Positive Prevention PLUS, a school-based adolescent pregnancy prevention program on delaying sexual intercourse, birth control use, and pregnancy. I randomly assigned a diverse sample of ninth grade students in 21 suburban public high schools in California into treatment (n = 2483) and control (n = 1784) groups that participated in a clustered randomized controlled trial. Between October 2013 and May 2014, participants completed baseline and 6-month follow-up surveys regarding sexual behavior and pregnancy. Participants in the treatment group were offered Positive Prevention PLUS, an 11-lesson adolescent pregnancy prevention program. The program had statistically significant impacts on delaying sexual intercourse and increasing the use of birth control. However, I detected no program effect on pregnancy rates at 6-month follow-up. The Positive Prevention PLUS program demonstrated positive impacts on adolescent sexual behavior. This suggests that programs that focus on having students practice risk reduction skills may delay sexual activity and increase birth control use.

Statistical characterization of the standard map

Science.gov (United States)

Ruiz, Guiomar; Tirnakli, Ugur; Borges, Ernesto P.; Tsallis, Constantino

2017-06-01

The standard map, paradigmatic conservative system in the (x, p) phase space, has been recently shown (Tirnakli and Borges (2016 Sci. Rep. 6 23644)) to exhibit interesting statistical behaviors directly related to the value of the standard map external parameter K. A comprehensive statistical numerical description is achieved in the present paper. More precisely, for large values of K (e.g. K  =  10) where the Lyapunov exponents are neatly positive over virtually the entire phase space consistently with Boltzmann-Gibbs (BG) statistics, we verify that the q-generalized indices related to the entropy production q{ent} , the sensitivity to initial conditions q{sen} , the distribution of a time-averaged (over successive iterations) phase-space coordinate q{stat} , and the relaxation to the equilibrium final state q{rel} , collapse onto a fixed point, i.e. q{ent}=q{sen}=q{stat}=q{rel}=1 . In remarkable contrast, for small values of K (e.g. K  =  0.2) where the Lyapunov exponents are virtually zero over the entire phase space, we verify q{ent}=q{sen}=0 , q{stat} ≃ 1.935 , and q{rel} ≃1.4 . The situation corresponding to intermediate values of K, where both stable orbits and a chaotic sea are present, is discussed as well. The present results transparently illustrate when BG behavior and/or q-statistical behavior are observed.

Multivariate Statistical Analysis of Water Quality data in Indian River Lagoon, Florida

Science.gov (United States)

Sayemuzzaman, M.; Ye, M.

2015-12-01

The Indian River Lagoon, is part of the longest barrier island complex in the United States, is a region of particular concern to the environmental scientist because of the rapid rate of human development throughout the region and the geographical position in between the colder temperate zone and warmer sub-tropical zone. Thus, the surface water quality analysis in this region always brings the newer information. In this present study, multivariate statistical procedures were applied to analyze the spatial and temporal water quality in the Indian River Lagoon over the period 1998-2013. Twelve parameters have been analyzed on twelve key water monitoring stations in and beside the lagoon on monthly datasets (total of 27,648 observations). The dataset was treated using cluster analysis (CA), principle component analysis (PCA) and non-parametric trend analysis. The CA was used to cluster twelve monitoring stations into four groups, with stations on the similar surrounding characteristics being in the same group. The PCA was then applied to the similar groups to find the important water quality parameters. The principal components (PCs), PC1 to PC5 was considered based on the explained cumulative variances 75% to 85% in each cluster groups. Nutrient species (phosphorus and nitrogen), salinity, specific conductivity and erosion factors (TSS, Turbidity) were major variables involved in the construction of the PCs. Statistical significant positive or negative trends and the abrupt trend shift were detected applying Mann-Kendall trend test and Sequential Mann-Kendall (SQMK), for each individual stations for the important water quality parameters. Land use land cover change pattern, local anthropogenic activities and extreme climate such as drought might be associated with these trends. This study presents the multivariate statistical assessment in order to get better information about the quality of surface water. Thus, effective pollution control/management of the surface