Theodorsson-Norheim, E
1986-08-01
Multiple t tests at a fixed p level are frequently used to analyse biomedical data where analysis of variance followed by multiple comparisons or the adjustment of the p values according to Bonferroni would be more appropriate. The Kruskal-Wallis test is a nonparametric 'analysis of variance' which may be used to compare several independent samples. The present program is written in an elementary subset of BASIC and will perform Kruskal-Wallis test followed by multiple comparisons between the groups on practically any computer programmable in BASIC.
A SAS(®) macro implementation of a multiple comparison post hoc test for a Kruskal-Wallis analysis.
Elliott, Alan C; Hynan, Linda S
2011-04-01
The Kruskal-Wallis (KW) nonparametric analysis of variance is often used instead of a standard one-way ANOVA when data are from a suspected non-normal population. The KW omnibus procedure tests for some differences between groups, but provides no specific post hoc pair wise comparisons. This paper provides a SAS(®) macro implementation of a multiple comparison test based on significant Kruskal-Wallis results from the SAS NPAR1WAY procedure. The implementation is designed for up to 20 groups at a user-specified alpha significance level. A Monte-Carlo simulation compared this nonparametric procedure to commonly used parametric multiple comparison tests. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.
Multiple comparison analysis testing in ANOVA.
McHugh, Mary L
2011-01-01
The Analysis of Variance (ANOVA) test has long been an important tool for researchers conducting studies on multiple experimental groups and one or more control groups. However, ANOVA cannot provide detailed information on differences among the various study groups, or on complex combinations of study groups. To fully understand group differences in an ANOVA, researchers must conduct tests of the differences between particular pairs of experimental and control groups. Tests conducted on subsets of data tested previously in another analysis are called post hoc tests. A class of post hoc tests that provide this type of detailed information for ANOVA results are called "multiple comparison analysis" tests. The most commonly used multiple comparison analysis statistics include the following tests: Tukey, Newman-Keuls, Scheffee, Bonferroni and Dunnett. These statistical tools each have specific uses, advantages and disadvantages. Some are best used for testing theory while others are useful in generating new theory. Selection of the appropriate post hoc test will provide researchers with the most detailed information while limiting Type 1 errors due to alpha inflation.
Brown, Angus M
2010-04-01
The objective of the method described in this paper is to develop a spreadsheet template for the purpose of comparing multiple sample means. An initial analysis of variance (ANOVA) test on the data returns F--the test statistic. If F is larger than the critical F value drawn from the F distribution at the appropriate degrees of freedom, convention dictates rejection of the null hypothesis and allows subsequent multiple comparison testing to determine where the inequalities between the sample means lie. A variety of multiple comparison methods are described that return the 95% confidence intervals for differences between means using an inclusive pairwise comparison of the sample means. 2009 Elsevier Ireland Ltd. All rights reserved.
Reporting of analyses from randomized controlled trials with multiple arms: a systematic review.
Baron, Gabriel; Perrodeau, Elodie; Boutron, Isabelle; Ravaud, Philippe
2013-03-27
Multiple-arm randomized trials can be more complex in their design, data analysis, and result reporting than two-arm trials. We conducted a systematic review to assess the reporting of analyses in reports of randomized controlled trials (RCTs) with multiple arms. The literature in the MEDLINE database was searched for reports of RCTs with multiple arms published in 2009 in the core clinical journals. Two reviewers extracted data using a standardized extraction form. In total, 298 reports were identified. Descriptions of the baseline characteristics and outcomes per group were missing in 45 reports (15.1%) and 48 reports (16.1%), respectively. More than half of the articles (n = 171, 57.4%) reported that a planned global test comparison was used (that is, assessment of the global differences between all groups), but 67 (39.2%) of these 171 articles did not report details of the planned analysis. Of the 116 articles reporting a global comparison test, 12 (10.3%) did not report the analysis as planned. In all, 60% of publications (n = 180) described planned pairwise test comparisons (that is, assessment of the difference between two groups), but 20 of these 180 articles (11.1%) did not report the pairwise test comparisons. Of the 204 articles reporting pairwise test comparisons, the comparisons were not planned for 44 (21.6%) of them. Less than half the reports (n = 137; 46%) provided baseline and outcome data per arm and reported the analysis as planned. Our findings highlight discrepancies between the planning and reporting of analyses in reports of multiple-arm trials.
Sonnemann, Eckart
2008-10-01
The introduction of sequentially rejective multiple test procedures (Einot and Gabriel, 1975; Naik, 1975; Holm, 1977; Holm, 1979) has caused considerable progress in the theory of multiple comparisons. Emphasizing the closure of multiple tests we give a survey of the general theory and its recent results in applications. Some new applications are given including a discussion of the connection with the theory of confidence regions.
Introducing Standardized EFL/ESL Exams
ERIC Educational Resources Information Center
Laborda, Jesus Garcia
2007-01-01
This article presents the features, and a brief comparison, of some of the most well-known high-stakes exams. They are classified in the following fashion: tests that only include multiple-choice questions, tests that include writing and multiple-choice questions, and tests that include speaking questions. The tests reviewed are: BULATS, IELTS,…
Slotnick, Scott D
2017-07-01
Analysis of functional magnetic resonance imaging (fMRI) data typically involves over one hundred thousand independent statistical tests; therefore, it is necessary to correct for multiple comparisons to control familywise error. In a recent paper, Eklund, Nichols, and Knutsson used resting-state fMRI data to evaluate commonly employed methods to correct for multiple comparisons and reported unacceptable rates of familywise error. Eklund et al.'s analysis was based on the assumption that resting-state fMRI data reflect null data; however, their 'null data' actually reflected default network activity that inflated familywise error. As such, Eklund et al.'s results provide no basis to question the validity of the thousands of published fMRI studies that have corrected for multiple comparisons or the commonly employed methods to correct for multiple comparisons.
ERIC Educational Resources Information Center
Liu, Jinghua; Guo, Hongwen; Dorans, Neil J.
2014-01-01
Maintaining score interchangeability and scale consistency is crucial for any testing programs that administer multiple forms across years. The use of a multiple linking design, which involves equating a new form to multiple old forms and averaging the conversions, has been proposed to control scale drift. However, the use of multiple linking…
Multiple Testing with Modified Bonferroni Methods.
ERIC Educational Resources Information Center
Li, Jianmin; And Others
This paper discusses the issue of multiple testing and overall Type I error rates in contexts other than multiple comparisons of means. It demonstrates, using a 5 x 5 correlation matrix, the application of 5 recently developed modified Bonferroni procedures developed by the following authors: (1) Y. Hochberg (1988); (2) B. S. Holland and M. D.…
ERIC Educational Resources Information Center
Hansen, James D.; Dexter, Lee
1997-01-01
Analysis of test item banks in 10 auditing textbooks found that 75% of questions violated one or more guidelines for multiple-choice items. In comparison, 70% of a certified public accounting exam bank had no violations. (SK)
Feedback enhances the positive effects and reduces the negative effects of multiple-choice testing.
Butler, Andrew C; Roediger, Henry L
2008-04-01
Multiple-choice tests are used frequently in higher education without much consideration of the impact this form of assessment has on learning. Multiple-choice testing enhances retention of the material tested (the testing effect); however, unlike other tests, multiple-choice can also be detrimental because it exposes students to misinformation in the form of lures. The selection of lures can lead students to acquire false knowledge (Roediger & Marsh, 2005). The present research investigated whether feedback could be used to boost the positive effects and reduce the negative effects of multiple-choice testing. Subjects studied passages and then received a multiple-choice test with immediate feedback, delayed feedback, or no feedback. In comparison with the no-feedback condition, both immediate and delayed feedback increased the proportion of correct responses and reduced the proportion of intrusions (i.e., lure responses from the initial multiple-choice test) on a delayed cued recall test. Educators should provide feedback when using multiple-choice tests.
ERIC Educational Resources Information Center
Willing, Sonja; Ostapczuk, Martin; Musch, Jochen
2015-01-01
Testwiseness--that is, the ability to find subtle cues towards the solution by the simultaneous comparison of the available answer options--threatens the validity of multiple-choice (MC) tests. Discrete-option multiple-choice (DOMC) has recently been proposed as a computerized alternative testing format for MC tests, and presumably allows for a…
Comparing Assessments of Students' Knowledge by Computerized Open-Ended and Multiple-Choice Tests.
ERIC Educational Resources Information Center
Anbar, Michael
1991-01-01
Interactive computerized tests accepting unrestricted natural-language input were used to assess knowledge of clinical biophysics at the State University of New York at Buffalo. Comparison of responses to open-ended sequential questions and multiple-choice questions on the same material found the two formats test different aspects of competence.…
Evaluation of MIMIC-Model Methods for DIF Testing with Comparison to Two-Group Analysis
ERIC Educational Resources Information Center
Woods, Carol M.
2009-01-01
Differential item functioning (DIF) occurs when an item on a test or questionnaire has different measurement properties for 1 group of people versus another, irrespective of mean differences on the construct. This study focuses on the use of multiple-indicator multiple-cause (MIMIC) structural equation models for DIF testing, parameterized as item…
Multiple comparisons permutation test for image based data mining in radiotherapy.
Chen, Chun; Witte, Marnix; Heemsbergen, Wilma; van Herk, Marcel
2013-12-23
: Comparing incidental dose distributions (i.e. images) of patients with different outcomes is a straightforward way to explore dose-response hypotheses in radiotherapy. In this paper, we introduced a permutation test that compares images, such as dose distributions from radiotherapy, while tackling the multiple comparisons problem. A test statistic Tmax was proposed that summarizes the differences between the images into a single value and a permutation procedure was employed to compute the adjusted p-value. We demonstrated the method in two retrospective studies: a prostate study that relates 3D dose distributions to failure, and an esophagus study that relates 2D surface dose distributions of the esophagus to acute esophagus toxicity. As a result, we were able to identify suspicious regions that are significantly associated with failure (prostate study) or toxicity (esophagus study). Permutation testing allows direct comparison of images from different patient categories and is a useful tool for data mining in radiotherapy.
Chen, Xiao; Lu, Bin; Yan, Chao-Gan
2018-01-01
Concerns regarding reproducibility of resting-state functional magnetic resonance imaging (R-fMRI) findings have been raised. Little is known about how to operationally define R-fMRI reproducibility and to what extent it is affected by multiple comparison correction strategies and sample size. We comprehensively assessed two aspects of reproducibility, test-retest reliability and replicability, on widely used R-fMRI metrics in both between-subject contrasts of sex differences and within-subject comparisons of eyes-open and eyes-closed (EOEC) conditions. We noted permutation test with Threshold-Free Cluster Enhancement (TFCE), a strict multiple comparison correction strategy, reached the best balance between family-wise error rate (under 5%) and test-retest reliability/replicability (e.g., 0.68 for test-retest reliability and 0.25 for replicability of amplitude of low-frequency fluctuations (ALFF) for between-subject sex differences, 0.49 for replicability of ALFF for within-subject EOEC differences). Although R-fMRI indices attained moderate reliabilities, they replicated poorly in distinct datasets (replicability < 0.3 for between-subject sex differences, < 0.5 for within-subject EOEC differences). By randomly drawing different sample sizes from a single site, we found reliability, sensitivity and positive predictive value (PPV) rose as sample size increased. Small sample sizes (e.g., < 80 [40 per group]) not only minimized power (sensitivity < 2%), but also decreased the likelihood that significant results reflect "true" effects (PPV < 0.26) in sex differences. Our findings have implications for how to select multiple comparison correction strategies and highlight the importance of sufficiently large sample sizes in R-fMRI studies to enhance reproducibility. Hum Brain Mapp 39:300-318, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.
Simultaneous Inference Procedures for Means.
ERIC Educational Resources Information Center
Krishnaiah, P. R.
Some aspects of simultaneous tests for means are reviewed. Specifically, the comparison of univariate or multivariate normal populations based on the values of the means or mean vectors when the variances or covariance matrices are equal is discussed. Tukey's and Dunnett's tests for multiple comparisons of means, Scheffe's method of examining…
Mi, Zhibao; Novitzky, Dimitri; Collins, Joseph F; Cooper, David KC
2015-01-01
The management of brain-dead organ donors is complex. The use of inotropic agents and replacement of depleted hormones (hormonal replacement therapy) is crucial for successful multiple organ procurement, yet the optimal hormonal replacement has not been identified, and the statistical adjustment to determine the best selection is not trivial. Traditional pair-wise comparisons between every pair of treatments, and multiple comparisons to all (MCA), are statistically conservative. Hsu’s multiple comparisons with the best (MCB) – adapted from the Dunnett’s multiple comparisons with control (MCC) – has been used for selecting the best treatment based on continuous variables. We selected the best hormonal replacement modality for successful multiple organ procurement using a two-step approach. First, we estimated the predicted margins by constructing generalized linear models (GLM) or generalized linear mixed models (GLMM), and then we applied the multiple comparison methods to identify the best hormonal replacement modality given that the testing of hormonal replacement modalities is independent. Based on 10-year data from the United Network for Organ Sharing (UNOS), among 16 hormonal replacement modalities, and using the 95% simultaneous confidence intervals, we found that the combination of thyroid hormone, a corticosteroid, antidiuretic hormone, and insulin was the best modality for multiple organ procurement for transplantation. PMID:25565890
Total-dose radiation effects data for semiconductor devices, volume 3
NASA Technical Reports Server (NTRS)
Price, W. E.; Martin, K. E.; Nichols, D. K.; Gauthier, M. K.; Brown, S. F.
1982-01-01
Volume 3 of this three-volume set provides a detailed analysis of the data in Volumes 1 and 2, most of which was generated for the Galileo Orbiter Program in support of NASA space programs. Volume 1 includes total ionizing dose radiation test data on diodes, bipolar transistors, field effect transistors, and miscellaneous discrete solid-state devices. Volume 2 includes similar data on integrated circuits and a few large-scale integrated circuits. The data of Volumes 1 and 2 are combined in graphic format in Volume 3 to provide a comparison of radiation sensitivities of devices of a given type and different manufacturer, a comparison of multiple tests for a single data code, a comparison of multiple tests for a single lot, and a comparison of radiation sensitivities vs time (date codes). All data were generated using a steady-state 2.5-MeV electron source (Dynamitron) or a Cobalt-60 gamma ray source. The data that compose Volume 3 represent 26 different device types, 224 tests, and a total of 1040 devices. A comparison of the effects of steady-state electrons and Cobat-60 gamma rays is also presented.
A Standard Platform for Testing and Comparison of MDAO Architectures
NASA Technical Reports Server (NTRS)
Gray, Justin S.; Moore, Kenneth T.; Hearn, Tristan A.; Naylor, Bret A.
2012-01-01
The Multidisciplinary Design Analysis and Optimization (MDAO) community has developed a multitude of algorithms and techniques, called architectures, for performing optimizations on complex engineering systems which involve coupling between multiple discipline analyses. These architectures seek to efficiently handle optimizations with computationally expensive analyses including multiple disciplines. We propose a new testing procedure that can provide a quantitative and qualitative means of comparison among architectures. The proposed test procedure is implemented within the open source framework, OpenMDAO, and comparative results are presented for five well-known architectures: MDF, IDF, CO, BLISS, and BLISS-2000. We also demonstrate how using open source soft- ware development methods can allow the MDAO community to submit new problems and architectures to keep the test suite relevant.
ERIC Educational Resources Information Center
Solano-Flores, Guillermo; Wang, Chao; Shade, Chelsey
2016-01-01
We examined multimodality (the representation of information in multiple semiotic modes) in the context of international test comparisons. Using Program of International Student Assessment (PISA)-2009 data, we examined the correlation of the difficulty of science items and the complexity of their illustrations. We observed statistically…
NASA Technical Reports Server (NTRS)
Jain, Abhinandan; Cameron, Jonathan M.; Myint, Steven
2013-01-01
This software runs a suite of arbitrary software tests spanning various software languages and types of tests (unit level, system level, or file comparison tests). The dtest utility can be set to automate periodic testing of large suites of software, as well as running individual tests. It supports distributing multiple tests over multiple CPU cores, if available. The dtest tool is a utility program (written in Python) that scans through a directory (and its subdirectories) and finds all directories that match a certain pattern and then executes any tests in that directory as described in simple configuration files.
Multiple comparisons permutation test for image based data mining in radiotherapy
2013-01-01
Comparing incidental dose distributions (i.e. images) of patients with different outcomes is a straightforward way to explore dose-response hypotheses in radiotherapy. In this paper, we introduced a permutation test that compares images, such as dose distributions from radiotherapy, while tackling the multiple comparisons problem. A test statistic Tmax was proposed that summarizes the differences between the images into a single value and a permutation procedure was employed to compute the adjusted p-value. We demonstrated the method in two retrospective studies: a prostate study that relates 3D dose distributions to failure, and an esophagus study that relates 2D surface dose distributions of the esophagus to acute esophagus toxicity. As a result, we were able to identify suspicious regions that are significantly associated with failure (prostate study) or toxicity (esophagus study). Permutation testing allows direct comparison of images from different patient categories and is a useful tool for data mining in radiotherapy. PMID:24365155
Gregori, Bruno; Papazachariadis, Odysseas; Farruggia, Alfonsa; Accornero, Neri
2011-01-15
Optic neuritis related to multiple sclerosis and diabetic retinopathy are relatively selective post-retinal and retinal vision disorders. Vision impairment in both conditions is reliably measured by testing critical fusion frequency (CFF). To examine color vision, we measured the CFF in response to red and blue stimuli, and tested CFF values in patients without evident vision impairment. To ensure that differences in CFF values in a given subject depended only on color perception we displayed red and blue flickering stimuli at equal luminance. CFF to red or blue stimuli were compared in patients with medical history of optic neuritis related to multiple sclerosis (post-retinal vision impairment), patients with diabetic retinopathy (retinal vision impairment) and healthy subjects. The test procedure disclosed altered CFF values for red and blue stimuli in both groups of patients studied. The comparison between the two groups disclosed a prevalent CFF impairment for red stimuli in patients with optic neuritis related to multiple sclerosis and for blue stimuli in patients with diabetic retinopathy. The differential color flicker test appears highly accurate in detecting color vision impairment. Comparison of the two color CFFs differentiates retinal from post-retinal visual disorders. Copyright © 2010 Elsevier B.V. All rights reserved.
Pick-N Multiple Choice-Exams: A Comparison of Scoring Algorithms
ERIC Educational Resources Information Center
Bauer, Daniel; Holzer, Matthias; Kopp, Veronika; Fischer, Martin R.
2011-01-01
To compare different scoring algorithms for Pick-N multiple correct answer multiple-choice (MC) exams regarding test reliability, student performance, total item discrimination and item difficulty. Data from six 3rd year medical students' end of term exams in internal medicine from 2005 to 2008 at Munich University were analysed (1,255 students,…
Gasparovic, Hrvoje; Borojevic, Marko; Malojcic, Branko; Gasparovic, Kristina; Biocina, Bojan
2013-10-01
Aortic manipulation releases embolic material, thereby enhancing the probability of adverse neurologic outcomes following coronary artery bypass grafting (CABG). We prospectively evaluated 59 patients undergoing CABG. Patients in the single (SC, n = 37) and multiple clamp (MC, n = 22) groups were comparable in relation to age and operative risk (p > 0.05). Neurocognitive evaluation consisted of the Auditory Verbal Learning Test (AVLT), Color Trails Test A, the Grooved Pegboard test and the Mini-Mental State Examination. Data acquisition was performed preoperatively, early postoperatively and at the 4-month follow-up. Intraoperative transcranial Doppler (TCD) monitoring was used to quantify the embolic load in relation to different aortic clamping strategies. Preoperative neurocognitive results were similar between the groups (p > 0.05). The incidence of postoperative delirium was greater in the MC group but this failed to reach statistical significance (23% vs 8%, p = 0.14). SC patients had fewer embolization signals (270 ± 181 vs 465 ± 160, p < 0.0001). Early postoperative neurocognitive results were depressed in comparison to preoperative values in both groups (p < 0.05 for multiple comparisons). The magnitude of this cognitive depression was greater in the MC group (p < 0.05 for multiple comparisons). Preoperative levels of neurocognition were restored at follow-up in the SC group in all tests except the AVLT. A trend towards improvements in neurocognitive performances at follow-up was also observed in the MC group. Residual attention, motor skill and memory deficits were, however, documented with multiple tests. In conclusion, the embolic burden was significantly lower in the SC group. This TCD imaging outcome translated into fewer early cognition deficits and superior late restoration of function.
Evaluating Neurotoxicity of a Mixture of Five OP Pesticides Using a Composite Score
The evaluation of the cumulative effects of neurotoxic pesticides often involves the analysis of both neurochemical and behavioral endpoints. Multiple statistical tests on many endpoints can greatly inflate Type I error rates. Multiple comparison adjustments are often overly con...
NASA Technical Reports Server (NTRS)
Feiveson, Alan H.; Ploutz-Snyder, Robert; Fiedler, James
2011-01-01
In their 2009 Annals of Statistics paper, Gavrilov, Benjamini, and Sarkar report the results of a simulation assessing the robustness of their adaptive step-down procedure (GBS) for controlling the false discovery rate (FDR) when normally distributed test statistics are serially correlated. In this study we extend the investigation to the case of multiple comparisons involving correlated non-central t-statistics, in particular when several treatments or time periods are being compared to a control in a repeated-measures design with many dependent outcome measures. In addition, we consider several dependence structures other than serial correlation and illustrate how the FDR depends on the interaction between effect size and the type of correlation structure as indexed by Foerstner s distance metric from an identity. The relationship between the correlation matrix R of the original dependent variables and R, the correlation matrix of associated t-statistics is also studied. In general R depends not only on R, but also on sample size and the signed effect sizes for the multiple comparisons.
Shifflett, Benjamin; Huang, Rong; Edland, Steven D
2017-01-01
Genotypic association studies are prone to inflated type I error rates if multiple hypothesis testing is performed, e.g., sequentially testing for recessive, multiplicative, and dominant risk. Alternatives to multiple hypothesis testing include the model independent genotypic χ 2 test, the efficiency robust MAX statistic, which corrects for multiple comparisons but with some loss of power, or a single Armitage test for multiplicative trend, which has optimal power when the multiplicative model holds but with some loss of power when dominant or recessive models underlie the genetic association. We used Monte Carlo simulations to describe the relative performance of these three approaches under a range of scenarios. All three approaches maintained their nominal type I error rates. The genotypic χ 2 and MAX statistics were more powerful when testing a strictly recessive genetic effect or when testing a dominant effect when the allele frequency was high. The Armitage test for multiplicative trend was most powerful for the broad range of scenarios where heterozygote risk is intermediate between recessive and dominant risk. Moreover, all tests had limited power to detect recessive genetic risk unless the sample size was large, and conversely all tests were relatively well powered to detect dominant risk. Taken together, these results suggest the general utility of the multiplicative trend test when the underlying genetic model is unknown.
Adaptive graph-based multiple testing procedures
Klinglmueller, Florian; Posch, Martin; Koenig, Franz
2016-01-01
Multiple testing procedures defined by directed, weighted graphs have recently been proposed as an intuitive visual tool for constructing multiple testing strategies that reflect the often complex contextual relations between hypotheses in clinical trials. Many well-known sequentially rejective tests, such as (parallel) gatekeeping tests or hierarchical testing procedures are special cases of the graph based tests. We generalize these graph-based multiple testing procedures to adaptive trial designs with an interim analysis. These designs permit mid-trial design modifications based on unblinded interim data as well as external information, while providing strong family wise error rate control. To maintain the familywise error rate, it is not required to prespecify the adaption rule in detail. Because the adaptive test does not require knowledge of the multivariate distribution of test statistics, it is applicable in a wide range of scenarios including trials with multiple treatment comparisons, endpoints or subgroups, or combinations thereof. Examples of adaptations are dropping of treatment arms, selection of subpopulations, and sample size reassessment. If, in the interim analysis, it is decided to continue the trial as planned, the adaptive test reduces to the originally planned multiple testing procedure. Only if adaptations are actually implemented, an adjusted test needs to be applied. The procedure is illustrated with a case study and its operating characteristics are investigated by simulations. PMID:25319733
DOE Office of Scientific and Technical Information (OSTI.GOV)
Fleming, P. A.; Van Wingerden, J. W.; Wright, A. D.
2012-01-01
In this paper we present results from an ongoing controller comparison study at the National Renewable Energy Laboratory's (NREL's) National Wind Technology Center (NWTC). The intention of the study is to demonstrate the advantage of using modern multivariable methods for designing control systems for wind turbines versus conventional approaches. We will demonstrate the advantages through field-test results from experimental turbines located at the NWTC. At least two controllers are being developed side-by-side to meet an incrementally increasing number of turbine load-reduction objectives. The first, a multiple single-input, single-output (m-SISO) approach, uses separately developed decoupled and classicially tuned controllers, which is,more » to the best of our knowledge, common practice in the wind industry. The remaining controllers are developed using state-space multiple-input and multiple-output (MIMO) techniques to explicity account for coupling between loops and to optimize given known frequency structures of the turbine and disturbance. In this first publication from the study, we present the structure of the ongoing controller comparison experiment, the design process for the two controllers compared in this phase, and initial comparison results obtained in field-testing.« less
Comparison of standing volume estimates using optical dendrometers
Neil A. Clark; Stanley J. Zarnoch; Alexander Clark; Gregory A. Reams
2001-01-01
This study compared height and diameter measurements and volume estimates on 20 hardwood and 20 softwood stems using traditional optical dendrometers, an experimental camera instrument, and mechanical calipers. Multiple comparison tests showed significant differences among the means for lower stem diameters when the camera was used. There were no significant...
Comparison of Standing Volume Estimates Using Optical Dendrometers
Neil A. Clark; Stanley J. Zarnoch; Alexander Clark; Gregory A. Reams
2001-01-01
This study compared height and diameter measurements and volume estimates on 20 hardwood and 20 softwood stems using traditional optical dendrometers, an experimental camera instrument, and mechanical calipers. Multiple comparison tests showed significant differences among the means for lower stem diameters when the camera was used. There were no significant...
A Comparison of Three Tests of Mediation
ERIC Educational Resources Information Center
Warbasse, Rosalia E.
2009-01-01
A simulation study was conducted to evaluate the performance of three tests of mediation: the bias-corrected and accelerated bootstrap (Efron & Tibshirani, 1993), the asymmetric confidence limits test (MacKinnon, 2008), and a multiple regression approach described by Kenny, Kashy, and Bolger (1998). The evolution of these methods is reviewed and…
Alvin H. Yu; Garry Chick
2010-01-01
This study compared the utility of two different post-hoc tests after detecting significant differences within factors on multiple dependent variables using multivariate analysis of variance (MANOVA). We compared the univariate F test (the Scheffé method) to descriptive discriminant analysis (DDA) using an educational-tour survey of university study-...
Test Design Project: Studies in Test Bias. Annual Report.
ERIC Educational Resources Information Center
McArthur, David
Item bias in a multiple-choice test can be detected by appropriate analyses of the persons x items scoring matrix. This permits comparison of groups of examinees tested with the same instrument. The test may be biased if it is not measuring the same thing in comparable groups, if groups are responding to different aspects of the test items, or if…
Smerbeck, A M; Parrish, J; Yeh, E A; Hoogs, M; Krupp, Lauren B; Weinstock-Guttman, B; Benedict, R H B
2011-04-01
The Brief Visuospatial Memory Test - Revised (BVMTR) and the Symbol Digit Modalities Test (SDMT) oral-only administration are known to be sensitive to cerebral disease in adult samples, but pediatric norms are not available. A demographically balanced sample of healthy control children (N = 92) ages 6-17 was tested with the BVMTR and SDMT. Multiple regression analysis (MRA) was used to develop demographically controlled normative equations. This analysis provided equations that were then used to construct demographically adjusted z-scores for the BVMTR Trial 1, Trial 2, Trial 3, Total Learning, and Delayed Recall indices, as well as the SDMT total correct score. To demonstrate the utility of this approach, a comparison group of children with acute disseminated encephalomyelitis (ADEM) or multiple sclerosis (MS) were also assessed. We find that these visual processing tests discriminate neurological patients from controls. As the tests are validated in adult multiple sclerosis, they are likely to be useful in monitoring pediatric onset multiple sclerosis patients as they transition into adulthood.
Prado, Jérôme; Mutreja, Rachna; Zhang, Hongchuan; Mehta, Rucha; Desroches, Amy S.; Minas, Jennifer E.; Booth, James R.
2010-01-01
It has been proposed that recent cultural inventions such as symbolic arithmetic recycle evolutionary older neural mechanisms. A central assumption of this hypothesis is that the degree to which a pre-existing mechanism is recycled depends upon the degree of similarity between its initial function and the novel task. To test this assumption, we investigated whether the brain region involved in magnitude comparison in the intraparietal sulcus (IPS), localized by a numerosity comparison task, is recruited to a greater degree by arithmetic problems that involve number comparison (single-digit subtractions) than by problems that involve retrieving facts from memory (single-digit multiplications). Our results confirmed that subtractions are associated with greater activity in the IPS than multiplications, whereas multiplications elicit greater activity than subtractions in regions involved in verbal processing including the middle temporal gyrus and inferior frontal gyrus that were localized by a phonological processing task. Pattern analyses further indicated that the neural mechanisms more active for subtraction than multiplication in the IPS overlap with those involved in numerosity comparison, and that the strength of this overlap predicts inter-individual performance in the subtraction task. These findings provide novel evidence that elementary arithmetic relies on the co-option of evolutionary older neural circuits. PMID:21246667
Multiple Sources of Test Bias on the WISC-R and Bender-Gestalt Test.
ERIC Educational Resources Information Center
Oakland, Thomas; Feigenbaum, David
1979-01-01
Assessed test bias on the Wechsler Intelligence Test for Children-Revised (WISC-R) and Bender-Gestalt. On the Bender, evidence of bias was infrequent and irregular. On the WISC-R, group differences were most discernible for age, sex, family structure, and race. Consistent patterns of bias were not apparent among comparison groups. (Author)
Biostatistics Series Module 3: Comparing Groups: Numerical Variables.
Hazra, Avijit; Gogtay, Nithya
2016-01-01
Numerical data that are normally distributed can be analyzed with parametric tests, that is, tests which are based on the parameters that define a normal distribution curve. If the distribution is uncertain, the data can be plotted as a normal probability plot and visually inspected, or tested for normality using one of a number of goodness of fit tests, such as the Kolmogorov-Smirnov test. The widely used Student's t-test has three variants. The one-sample t-test is used to assess if a sample mean (as an estimate of the population mean) differs significantly from a given population mean. The means of two independent samples may be compared for a statistically significant difference by the unpaired or independent samples t-test. If the data sets are related in some way, their means may be compared by the paired or dependent samples t-test. The t-test should not be used to compare the means of more than two groups. Although it is possible to compare groups in pairs, when there are more than two groups, this will increase the probability of a Type I error. The one-way analysis of variance (ANOVA) is employed to compare the means of three or more independent data sets that are normally distributed. Multiple measurements from the same set of subjects cannot be treated as separate, unrelated data sets. Comparison of means in such a situation requires repeated measures ANOVA. It is to be noted that while a multiple group comparison test such as ANOVA can point to a significant difference, it does not identify exactly between which two groups the difference lies. To do this, multiple group comparison needs to be followed up by an appropriate post hoc test. An example is the Tukey's honestly significant difference test following ANOVA. If the assumptions for parametric tests are not met, there are nonparametric alternatives for comparing data sets. These include Mann-Whitney U-test as the nonparametric counterpart of the unpaired Student's t-test, Wilcoxon signed-rank test as the counterpart of the paired Student's t-test, Kruskal-Wallis test as the nonparametric equivalent of ANOVA and the Friedman's test as the counterpart of repeated measures ANOVA.
A comparison of forest canopy transmittance estimators
E.R. Smith; Kurt H. Riitters
1994-01-01
Multiple sensors, and alternate statistical estimators, were tested for measuring canopy transmittance in four stands under a variety of sky conditions. On a given day, stand average transmittance estimates were insensitive to degree of synchronization of the sensors used to measure under-canopy and incoming radiation. In comparisons to periodic measurement of incoming...
ERIC Educational Resources Information Center
Schwarz, Amy Louise; Van Kleeck, Anne; Maguire, Mandy J.; Abdi, Herve
2017-01-01
To better understand how toddlers integrate multiple learning strategies to acquire verbs, we compared sensorimotor recruitment and comparison learning because both strategies are thought to boost children's access to scene-level information. For sensorimotor recruitment, we tested having toddlers use dolls as agents and compared this strategy…
DOE Office of Scientific and Technical Information (OSTI.GOV)
Fleming, P. A.; van Wingerden, J. W.; Wright, A. D.
2011-12-01
This paper presents the structure of an ongoing controller comparison experiment at NREL's National Wind Technology Center; the design process for the two controllers compared in this phase of the experiment, and initial comparison results obtained in field-testing. The intention of the study is to demonstrate the advantage of using modern multivariable methods for designing control systems for wind turbines versus conventional approaches. We will demonstrate the advantages through field-test results from experimental turbines located at the NWTC. At least two controllers are being developed side-by-side to meet an incrementally increasing number of turbine load-reduction objectives. The first, a multiplemore » single-input, single-output (m-SISO) approach, uses separately developed decoupled and classicially tuned controllers, which is, to the best of our knowledge, common practice in the wind industry. The remaining controllers are developed using state-space multiple-input and multiple-output (MIMO) techniques to explicity account for coupling between loops and to optimize given known frequency structures of the turbine and disturbance. In this first publication from the study, we present the structure of the ongoing controller comparison experiment, the design process for the two controllers compared in this phase, and initial comparison results obtained in field-testing.« less
Mass univariate analysis of event-related brain potentials/fields I: a critical tutorial review.
Groppe, David M; Urbach, Thomas P; Kutas, Marta
2011-12-01
Event-related potentials (ERPs) and magnetic fields (ERFs) are typically analyzed via ANOVAs on mean activity in a priori windows. Advances in computing power and statistics have produced an alternative, mass univariate analyses consisting of thousands of statistical tests and powerful corrections for multiple comparisons. Such analyses are most useful when one has little a priori knowledge of effect locations or latencies, and for delineating effect boundaries. Mass univariate analyses complement and, at times, obviate traditional analyses. Here we review this approach as applied to ERP/ERF data and four methods for multiple comparison correction: strong control of the familywise error rate (FWER) via permutation tests, weak control of FWER via cluster-based permutation tests, false discovery rate control, and control of the generalized FWER. We end with recommendations for their use and introduce free MATLAB software for their implementation. Copyright © 2011 Society for Psychophysiological Research.
ERIC Educational Resources Information Center
Longenbecker, Sueann; Wood, Peter H.
1984-01-01
Scores from the National Board Dental Hygiene Examination (NBDHE) served as the criterion variable in a comparison of the predictive validity of the Dental Hygiene Aptitude Tests (DHAT) and the ACT Assessment tests. The DHAT-Science and Verbal tests combined to produce the highest multiple correlation with NBDHE scores. (Author/DWH)
Improvements in simulation of multiple scattering effects in ATLAS fast simulation
DOE Office of Scientific and Technical Information (OSTI.GOV)
Basalaev, A. E., E-mail: artem.basalaev@cern.ch
Fast ATLAS Tracking Simulation (Fatras) package was verified on single layer geometry with respect to full simulation with GEANT4. Fatras hadronic interactions and multiple scattering simulation were studied in comparison with GEANT4. Disagreement was found in multiple scattering distributions of primary charged particles (μ, π, e). A new model for multiple scattering simulation was implemented in Fatras. The model was based on R. Frühwirth’s mixture models. New model was tested on single layer geometry and a good agreement with GEANT4 was achieved. Also a comparison of reconstructed tracks’ parameters was performed for Inner Detector geometry, and Fatras with new multiplemore » scattering model proved to have better agreement with GEANT4. New model of multiple scattering was added as a part of Fatras package in the development release of ATLAS software—ATHENA.« less
Owen, Rhiannon K; Cooper, Nicola J; Quinn, Terence J; Lees, Rosalind; Sutton, Alex J
2018-07-01
Network meta-analyses (NMA) have extensively been used to compare the effectiveness of multiple interventions for health care policy and decision-making. However, methods for evaluating the performance of multiple diagnostic tests are less established. In a decision-making context, we are often interested in comparing and ranking the performance of multiple diagnostic tests, at varying levels of test thresholds, in one simultaneous analysis. Motivated by an example of cognitive impairment diagnosis following stroke, we synthesized data from 13 studies assessing the efficiency of two diagnostic tests: Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA), at two test thresholds: MMSE <25/30 and <27/30, and MoCA <22/30 and <26/30. Using Markov chain Monte Carlo (MCMC) methods, we fitted a bivariate network meta-analysis model incorporating constraints on increasing test threshold, and accounting for the correlations between multiple test accuracy measures from the same study. We developed and successfully fitted a model comparing multiple tests/threshold combinations while imposing threshold constraints. Using this model, we found that MoCA at threshold <26/30 appeared to have the best true positive rate, whereas MMSE at threshold <25/30 appeared to have the best true negative rate. The combined analysis of multiple tests at multiple thresholds allowed for more rigorous comparisons between competing diagnostics tests for decision making. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.
ERIC Educational Resources Information Center
Roid, Gale; And Others
Several measurement theorists have convincingly argued that methods of writing test questions, particularly for criterion-referenced tests, should be based on operationally defined rules. This study was designed to examine and further refine a method for objectively generating multiple-choice questions for prose instructional materials. Important…
Atypical nucleus accumbens morphology in psychopathy: another limbic piece in the puzzle.
Boccardi, Marina; Bocchetta, Martina; Aronen, Hannu J; Repo-Tiihonen, Eila; Vaurio, Olli; Thompson, Paul M; Tiihonen, Jari; Frisoni, Giovanni B
2013-01-01
Psychopathy has been associated with increased putamen and striatum volumes. The nucleus accumbens - a key structure in reversal learning, less effective in psychopathy - has not yet received specific attention. Moreover, basal ganglia morphology has never been explored. We examined the morphology of the caudate, putamen and accumbens, manually segmented from magnetic resonance images of 26 offenders (age: 32.5 ± 8.4) with medium-high psychopathy (mean PCL-R=30 ± 5) and 25 healthy controls (age: 34.6 ± 10.8). Local differences were statistically modeled using a surface-based radial distance mapping method (p<0.05; multiple comparisons correction through permutation tests). In psychopathy, the caudate and putamen had normal global volume, but different morphology, significant after correction for multiple comparisons, for the right dorsal putamen (permutation test: p=0.02). The volume of the nucleus accumbens was 13% smaller in psychopathy (p corrected for multiple comparisons <0.006). The atypical morphology consisted of predominant anterior hypotrophy bilaterally (10-30%). Caudate and putamen local morphology displayed negative correlation with the lifestyle factor of the PCL-R (permutation test: p=0.05 and 0.03). From these data, psychopathy appears to be associated with an atypical striatal morphology, with highly significant global and local differences of the accumbens. This is consistent with the clinical syndrome and with theories of limbic involvement. Copyright © 2013 Elsevier Ltd. All rights reserved.
ERIC Educational Resources Information Center
Suh, Youngsuk; Talley, Anna E.
2015-01-01
This study compared and illustrated four differential distractor functioning (DDF) detection methods for analyzing multiple-choice items. The log-linear approach, two item response theory-model-based approaches with likelihood ratio tests, and the odds ratio approach were compared to examine the congruence among the four DDF detection methods.…
1981-06-01
normality and several types of nonnormality. Overall the rank transformation procedure seems to be the best. The Fisher’s LSD multiple comparisons procedure...the rank transformation procedure appears to maintain power better than Fisher’s LSD or the randomization proce- dures. The conclusion of this study...best. The Fisher’s LSD multiple comparisons procedure in the one way and two way layouts iv compared with a randomization procedure and with the same
Benefits of Using Planned Comparisons Rather Than Post Hoc Tests: A Brief Review with Examples.
ERIC Educational Resources Information Center
DuRapau, Theresa M.
The rationale behind analysis of variance (including analysis of covariance and multiple analyses of variance and covariance) methods is reviewed, and unplanned and planned methods of evaluating differences between means are briefly described. Two advantages of using planned or a priori tests over unplanned or post hoc tests are presented. In…
A Comparison of Domain-Referenced and Classic Psychometric Test Construction Methods.
ERIC Educational Resources Information Center
Willoughby, Lee; And Others
This study compared a domain referenced approach with a traditional psychometric approach in the construction of a test. Results of the December, 1975 Quarterly Profile Exam (QPE) administered to 400 examinees at a university were the source of data. The 400 item QPE is a five alternative multiple choice test of information a "safe"…
Association analysis of multiple traits by an approach of combining P values.
Chen, Lili; Wang, Yong; Zhou, Yajing
2018-03-01
Increasing evidence shows that one variant can affect multiple traits, which is a widespread phenomenon in complex diseases. Joint analysis of multiple traits can increase statistical power of association analysis and uncover the underlying genetic mechanism. Although there are many statistical methods to analyse multiple traits, most of these methods are usually suitable for detecting common variants associated with multiple traits. However, because of low minor allele frequency of rare variant, these methods are not optimal for rare variant association analysis. In this paper, we extend an adaptive combination of P values method (termed ADA) for single trait to test association between multiple traits and rare variants in the given region. For a given region, we use reverse regression model to test each rare variant associated with multiple traits and obtain the P value of single-variant test. Further, we take the weighted combination of these P values as the test statistic. Extensive simulation studies show that our approach is more powerful than several other comparison methods in most cases and is robust to the inclusion of a high proportion of neutral variants and the different directions of effects of causal variants.
Zhang, Niu; Chawla, Sudeep
2012-01-01
This study examined the effect of implementing instructional video in ophthalmic physical examination teaching on chiropractic students' laboratory physical examination skills and written test results. Instructional video clips of ophthalmic physical examination, consisting of both standard procedures and common mistakes, were created and used for laboratory teaching. The video clips were also available for student review after class. Students' laboratory skills and written test results were analyzed and compared using one-way analysis of variance (ANOVA) and post hoc multiple comparison tests among three study cohorts: the comparison cohort who did not utilize the instructional videos as a tool, the standard video cohort who viewed only the standard procedure of video clips, and the mistake-referenced video cohort who viewed video clips containing both standard procedure and common mistakes. One-way ANOVA suggested a significant difference of lab results among the three cohorts. Post hoc multiple comparisons further revealed that the mean scores of both video cohorts were significantly higher than that of the comparison cohort (p < .001). There was, however, no significant difference of the mean scores between the two video cohorts (p > .05). However, the percentage of students having a perfect score was the highest in the mistake-referenced video cohort. There was no significant difference of written test scores among all three cohorts (p > .05). The instructional video of the standard procedure improves chiropractic students' ophthalmic physical examination skills, which may be further enhanced by implementing a mistake-referenced instructional video.
Najafi, Mostafa; Akouchekian, Shahla; Ghaderi, Alireza; Mahaki, Behzad; Rezaei, Mariam
2017-01-01
Attention deficit and hyperactivity disorder (ADHD) is a common psychological problem during childhood. This study aimed to evaluate multiple intelligences profiles of children with ADHD in comparison with non-ADHD. This cross-sectional descriptive analytical study was done on 50 children of 6-13 years old in two groups of with and without ADHD. Children with ADHD were referred to Clinics of Child and Adolescent Psychiatry, Isfahan University of Medical Sciences, in 2014. Samples were selected based on clinical interview (based on Diagnostic and Statistical Manual of Mental Disorders IV and parent-teacher strengths and difficulties questionnaire), which was done by psychiatrist and psychologist. Raven intelligence quotient (IQ) test was used, and the findings were compared to the results of multiple intelligences test. Data analysis was done using a multivariate analysis of covariance using SPSS20 software. Comparing the profiles of multiple intelligence among two groups, there are more kinds of multiple intelligences in control group than ADHD group, a difference which has been more significant in logical, interpersonal, and intrapersonal intelligence ( P < 0.05). There was no significant difference with the other kinds of multiple intelligences in two groups ( P > 0.05). The IQ average score in the control group and ADHD group was 102.42 ± 16.26 and 96.72 ± 16.06, respectively, that reveals the negative effect of ADHD on IQ average value. There was an insignificance relationship between linguistic and naturalist intelligence ( P > 0.05). However, in other kinds of multiple intelligences, direct and significant relationships were observed ( P < 0.05). Since the levels of IQ (Raven test) and MI in control group were more significant than ADHD group, ADHD is likely to be associated with logical-mathematical, interpersonal, and intrapersonal profiles.
ERIC Educational Resources Information Center
Paek, Insu; Park, Hyun-Jeong; Cai, Li; Chi, Eunlim
2014-01-01
Typically a longitudinal growth modeling based on item response theory (IRT) requires repeated measures data from a single group with the same test design. If operational or item exposure problems are present, the same test may not be employed to collect data for longitudinal analyses and tests at multiple time points are constructed with unique…
Kim, Eun Sook; Cao, Chunhua
2015-01-01
Considering that group comparisons are common in social science, we examined two latent group mean testing methods when groups of interest were either at the between or within level of multilevel data: multiple-group multilevel confirmatory factor analysis (MG ML CFA) and multilevel multiple-indicators multiple-causes modeling (ML MIMIC). The performance of these methods were investigated through three Monte Carlo studies. In Studies 1 and 2, either factor variances or residual variances were manipulated to be heterogeneous between groups. In Study 3, which focused on within-level multiple-group analysis, six different model specifications were considered depending on how to model the intra-class group correlation (i.e., correlation between random effect factors for groups within cluster). The results of simulations generally supported the adequacy of MG ML CFA and ML MIMIC for multiple-group analysis with multilevel data. The two methods did not show any notable difference in the latent group mean testing across three studies. Finally, a demonstration with real data and guidelines in selecting an appropriate approach to multilevel multiple-group analysis are provided.
Eisinga, Rob; Heskes, Tom; Pelzer, Ben; Te Grotenhuis, Manfred
2017-01-25
The Friedman rank sum test is a widely-used nonparametric method in computational biology. In addition to examining the overall null hypothesis of no significant difference among any of the rank sums, it is typically of interest to conduct pairwise comparison tests. Current approaches to such tests rely on large-sample approximations, due to the numerical complexity of computing the exact distribution. These approximate methods lead to inaccurate estimates in the tail of the distribution, which is most relevant for p-value calculation. We propose an efficient, combinatorial exact approach for calculating the probability mass distribution of the rank sum difference statistic for pairwise comparison of Friedman rank sums, and compare exact results with recommended asymptotic approximations. Whereas the chi-squared approximation performs inferiorly to exact computation overall, others, particularly the normal, perform well, except for the extreme tail. Hence exact calculation offers an improvement when small p-values occur following multiple testing correction. Exact inference also enhances the identification of significant differences whenever the observed values are close to the approximate critical value. We illustrate the proposed method in the context of biological machine learning, were Friedman rank sum difference tests are commonly used for the comparison of classifiers over multiple datasets. We provide a computationally fast method to determine the exact p-value of the absolute rank sum difference of a pair of Friedman rank sums, making asymptotic tests obsolete. Calculation of exact p-values is easy to implement in statistical software and the implementation in R is provided in one of the Additional files and is also available at http://www.ru.nl/publish/pages/726696/friedmanrsd.zip .
40 CFR 258.53 - Ground-water sampling and analysis requirements.
Code of Federal Regulations, 2011 CFR
2011-07-01
... include consistent sampling and analysis procedures that are designed to ensure monitoring results that... testing period. If a multiple comparisons procedure is used, the Type I experiment wise error rate for...
Two enzyme-linked immunosorbent assay (ELISA) methods were evaluated for the determination of 3,5,6-trichloro-2-pyridinol (3,5,6-TCP) in multiple sample media (dust, soil, food, and urine). The dust and soil samples were analyzed by a commercial RaPID immunoassay testing kit. ...
Robust Lee local statistic filter for removal of mixed multiplicative and impulse noise
NASA Astrophysics Data System (ADS)
Ponomarenko, Nikolay N.; Lukin, Vladimir V.; Egiazarian, Karen O.; Astola, Jaakko T.
2004-05-01
A robust version of Lee local statistic filter able to effectively suppress the mixed multiplicative and impulse noise in images is proposed. The performance of the proposed modification is studied for a set of test images, several values of multiplicative noise variance, Gaussian and Rayleigh probability density functions of speckle, and different characteris-tics of impulse noise. The advantages of the designed filter in comparison to the conventional Lee local statistic filter and some other filters able to cope with mixed multiplicative+impulse noise are demonstrated.
Küçük, Fadime; Kara, Bilge; Poyraz, Esra Çoşkuner; İdiman, Egemen
2016-01-01
[Purpose] The aim of this study was to determine the effects of clinical Pilates in multiple sclerosis patients. [Subjects and Methods] Twenty multiple sclerosis patients were enrolled in this study. The participants were divided into two groups as the clinical Pilates and control groups. Cognition (Multiple Sclerosis Functional Composite), balance (Berg Balance Scale), physical performance (timed performance tests, Timed up and go test), tiredness (Modified Fatigue Impact scale), depression (Beck Depression Inventory), and quality of life (Multiple Sclerosis International Quality of Life Questionnaire) were measured before and after treatment in all participants. [Results] There were statistically significant differences in balance, timed performance, tiredness and Multiple Sclerosis Functional Composite tests between before and after treatment in the clinical Pilates group. We also found significant differences in timed performance tests, the Timed up and go test and the Multiple Sclerosis Functional Composite between before and after treatment in the control group. According to the difference analyses, there were significant differences in Multiple Sclerosis Functional Composite and Multiple Sclerosis International Quality of Life Questionnaire scores between the two groups in favor of the clinical Pilates group. There were statistically significant clinical differences in favor of the clinical Pilates group in comparison of measurements between the groups. Clinical Pilates improved cognitive functions and quality of life compared with traditional exercise. [Conclusion] In Multiple Sclerosis treatment, clinical Pilates should be used as a holistic approach by physical therapists. PMID:27134355
Küçük, Fadime; Kara, Bilge; Poyraz, Esra Çoşkuner; İdiman, Egemen
2016-03-01
[Purpose] The aim of this study was to determine the effects of clinical Pilates in multiple sclerosis patients. [Subjects and Methods] Twenty multiple sclerosis patients were enrolled in this study. The participants were divided into two groups as the clinical Pilates and control groups. Cognition (Multiple Sclerosis Functional Composite), balance (Berg Balance Scale), physical performance (timed performance tests, Timed up and go test), tiredness (Modified Fatigue Impact scale), depression (Beck Depression Inventory), and quality of life (Multiple Sclerosis International Quality of Life Questionnaire) were measured before and after treatment in all participants. [Results] There were statistically significant differences in balance, timed performance, tiredness and Multiple Sclerosis Functional Composite tests between before and after treatment in the clinical Pilates group. We also found significant differences in timed performance tests, the Timed up and go test and the Multiple Sclerosis Functional Composite between before and after treatment in the control group. According to the difference analyses, there were significant differences in Multiple Sclerosis Functional Composite and Multiple Sclerosis International Quality of Life Questionnaire scores between the two groups in favor of the clinical Pilates group. There were statistically significant clinical differences in favor of the clinical Pilates group in comparison of measurements between the groups. Clinical Pilates improved cognitive functions and quality of life compared with traditional exercise. [Conclusion] In Multiple Sclerosis treatment, clinical Pilates should be used as a holistic approach by physical therapists.
Comparison of performance criteria for evaluating stake test data
Stan T. Lebow; Patricia K. Lebow; Grant T. Kirker
2017-01-01
Stake tests are a critical part of evaluating durability of wood in ground-contact, but there is a lack of criteria for interpreting stake test results. This paper discusses criteria that might be used to determine if short term ratings indicate satisfactory longterm performance. Ratings of 19 by 19 mm stakes from multiple plots in the Harrison Experimental Forest,...
Program CONTRAST--A general program for the analysis of several survival or recovery rate estimates
Hines, J.E.; Sauer, J.R.
1989-01-01
This manual describes the use of program CONTRAST, which implements a generalized procedure for the comparison of several rate estimates. This method can be used to test both simple and composite hypotheses about rate estimates, and we discuss its application to multiple comparisons of survival rate estimates. Several examples of the use of program CONTRAST are presented. Program CONTRAST will run on IBM-cimpatible computers, and requires estimates of the rates to be tested, along with associated variance and covariance estimates.
The validity of three tests of temperament in guppies (Poecilia reticulata).
Burns, James G
2008-11-01
Differences in temperament (consistent differences among individuals in behavior) can have important effects on fitness-related activities such as dispersal and competition. However, evolutionary ecologists have put limited effort into validating their tests of temperament. This article attempts to validate three standard tests of temperament in guppies: the open-field test, emergence test, and novel-object test. Through multiple reliability trials, and comparison of results between different types of test, this study establishes the confidence that can be placed in these temperament tests. The open-field test is shown to be a good test of boldness and exploratory behavior; the open-field test was reliable when tested in multiple ways. There were problems with the emergence test and novel-object test, which leads one to conclude that the protocols used in this study should not be considered valid tests for this species. (PsycINFO Database Record (c) 2008 APA, all rights reserved).
21 CFR 320.27 - Guidelines on the design of a multiple-dose in vivo bioavailability study.
Code of Federal Regulations, 2014 CFR
2014-04-01
..., DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DRUGS FOR HUMAN USE BIOAVAILABILITY AND BIOEQUIVALENCE... therapeutic moiety in the body. (2) The test product and the reference material should be administered to...) Measurement of an acute pharmacological effect. When comparison of the test product and the reference material...
21 CFR 320.27 - Guidelines on the design of a multiple-dose in vivo bioavailability study.
Code of Federal Regulations, 2012 CFR
2012-04-01
..., DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DRUGS FOR HUMAN USE BIOAVAILABILITY AND BIOEQUIVALENCE... therapeutic moiety in the body. (2) The test product and the reference material should be administered to...) Measurement of an acute pharmacological effect. When comparison of the test product and the reference material...
21 CFR 320.27 - Guidelines on the design of a multiple-dose in vivo bioavailability study.
Code of Federal Regulations, 2013 CFR
2013-04-01
..., DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DRUGS FOR HUMAN USE BIOAVAILABILITY AND BIOEQUIVALENCE... therapeutic moiety in the body. (2) The test product and the reference material should be administered to...) Measurement of an acute pharmacological effect. When comparison of the test product and the reference material...
Comparison of two stand-alone CADe systems at multiple operating points
NASA Astrophysics Data System (ADS)
Sahiner, Berkman; Chen, Weijie; Pezeshk, Aria; Petrick, Nicholas
2015-03-01
Computer-aided detection (CADe) systems are typically designed to work at a given operating point: The device displays a mark if and only if the level of suspiciousness of a region of interest is above a fixed threshold. To compare the standalone performances of two systems, one approach is to select the parameters of the systems to yield a target false-positive rate that defines the operating point, and to compare the sensitivities at that operating point. Increasingly, CADe developers offer multiple operating points, which necessitates the comparison of two CADe systems involving multiple comparisons. To control the Type I error, multiple-comparison correction is needed for keeping the family-wise error rate (FWER) less than a given alpha-level. The sensitivities of a single modality at different operating points are correlated. In addition, the sensitivities of the two modalities at the same or different operating points are also likely to be correlated. It has been shown in the literature that when test statistics are correlated, well-known methods for controlling the FWER are conservative. In this study, we compared the FWER and power of three methods, namely the Bonferroni, step-up, and adjusted step-up methods in comparing the sensitivities of two CADe systems at multiple operating points, where the adjusted step-up method uses the estimated correlations. Our results indicate that the adjusted step-up method has a substantial advantage over other the two methods both in terms of the FWER and power.
Kneebone, Ian I.; Dewar, Sophie J.
2016-01-01
Background: The current study aimed to examine the psychometric properties of an attributional style measure that can be administered remotely, to people who have multiple sclerosis (MS). Methods: A total of 495 participants with MS were recruited. Participants completed the Attributional Style Questionnaire-Survey (ASQ-S) and two comparison measures of cognitive variables via postal survey on three occasions, each 12 months apart. Internal reliability, test-retest reliability and congruent validity were considered. Results: The internal reliability of the ASQ-S was good (α > 0.7). The test-retest correlations were significant, but failed to reach the 0.7 set. The congruent validity of the ASQ-S was established relative to the comparisons. Conclusions: The psychometric properties of the ASQ-S indicate that it shows promise as a tool for researchers investigating depression in people with MS and is likely sound to use clinically in this population. PMID:28450893
An introduction to multiplicity issues in clinical trials: the what, why, when and how.
Li, Guowei; Taljaard, Monica; Van den Heuvel, Edwin R; Levine, Mitchell Ah; Cook, Deborah J; Wells, George A; Devereaux, Philip J; Thabane, Lehana
2017-04-01
In clinical trials it is not uncommon to face a multiple testing problem which can have an impact on both type I and type II error rates, leading to inappropriate interpretation of trial results. Multiplicity issues may need to be considered at the design, analysis and interpretation stages of a trial. The proportion of trial reports not adequately correcting for multiple testing remains substantial. The purpose of this article is to provide an introduction to multiple testing issues in clinical trials, and to reduce confusion around the need for multiplicity adjustments. We use a tutorial, question-and-answer approach to address the key issues of why, when and how to consider multiplicity adjustments in trials. We summarize the relevant circumstances under which multiplicity adjustments ought to be considered, as well as options for carrying out multiplicity adjustments in terms of trial design factors including Population, Intervention/Comparison, Outcome, Time frame and Analysis (PICOTA). Results are presented in an easy-to-use table and flow diagrams. Confusion about multiplicity issues can be reduced or avoided by considering the potential impact of multiplicity on type I and II errors and, if necessary pre-specifying statistical approaches to either avoid or adjust for multiplicity in the trial protocol or analysis plan. © The Author 2016; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association.
Data for Room Fire Model Comparisons
Peacock, Richard D.; Davis, Sanford; Babrauskas, Vytenis
1991-01-01
With the development of models to predict fire growth and spread in buildings, there has been a concomitant evolution in the measurement and analysis of experimental data in real-scale fires. This report presents the types of analyses that can be used to examine large-scale room fire test data to prepare the data for comparison with zone-based fire models. Five sets of experimental data which can be used to test the limits of a typical two-zone fire model are detailed. A standard set of nomenclature describing the geometry of the building and the quantities measured in each experiment is presented. Availability of ancillary data (such as smaller-scale test results) is included. These descriptions, along with the data (available in computer-readable form) should allow comparisons between the experiment and model predictions. The base of experimental data ranges in complexity from one room tests with individual furniture items to a series of tests conducted in a multiple story hotel equipped with a zoned smoke control system. PMID:28184121
Data for Room Fire Model Comparisons.
Peacock, Richard D; Davis, Sanford; Babrauskas, Vytenis
1991-01-01
With the development of models to predict fire growth and spread in buildings, there has been a concomitant evolution in the measurement and analysis of experimental data in real-scale fires. This report presents the types of analyses that can be used to examine large-scale room fire test data to prepare the data for comparison with zone-based fire models. Five sets of experimental data which can be used to test the limits of a typical two-zone fire model are detailed. A standard set of nomenclature describing the geometry of the building and the quantities measured in each experiment is presented. Availability of ancillary data (such as smaller-scale test results) is included. These descriptions, along with the data (available in computer-readable form) should allow comparisons between the experiment and model predictions. The base of experimental data ranges in complexity from one room tests with individual furniture items to a series of tests conducted in a multiple story hotel equipped with a zoned smoke control system.
ERIC Educational Resources Information Center
Longabach, Tanya; Peyton, Vicki
2018-01-01
K-12 English language proficiency tests that assess multiple content domains (e.g., listening, speaking, reading, writing) often have subsections based on these content domains; scores assigned to these subsections are commonly known as subscores. Testing programs face increasing customer demands for the reporting of subscores in addition to the…
Pre-treatment red blood cell distribution width provides prognostic information in multiple myeloma.
Zhou, Di; Xu, Peipei; Peng, Miaoxin; Shao, Xiaoyan; Wang, Miao; Ouyang, Jian; Chen, Bing
2018-06-01
The red blood cell distribution width (RDW), a credible marker for abnormal erythropoiesis, has recently been studied as a prognostic factor in oncology, but its role in multiple myeloma (MM) hasn't been thoroughly investigated. We performed a retrospective study in 162 patients with multiple myeloma. Categorical parameters were analyzed using Pearson chi-squared test. The Mann-Whitney and Wilcoxon tests were used for group comparisons. Comparisons of repeated samples data were analyzed with the general linear model repeated-measures procedure. The Kaplan-Meier product-limit method was used to determine OS and PFS, and the differences were assessed by the log-rank test. High RDW baseline was significantly associated with indexes including haemoglobin, bone marrow plasma cell infiltration, and cytogenetics risk stratification. After chemotherapy, the overall response rate (ORR) decreased as RDW baseline increased. In 24 patients with high RDW baseline, it was revealed RDW value decreased when patients achieved complete remission (CR), but increased when the disease progressed. The normal-RDW baseline group showed both longer overall survival (OS) and progression-free survival (PFS) than the high-RDW baseline group. Our study suggests pre-treatment RDW level is a prognostic factor in MM and should be regarded as an important parameter for assessment of therapeutic efficiency. Copyright © 2018. Published by Elsevier B.V.
Willmes, K
1985-08-01
Methods for the analysis of a single subject's test profile(s) proposed by Huber (1973) are applied to the Aachen Aphasia Test (AAT). The procedures are based on the classical test theory model (Lord & Novick, 1968) and are suited for any (achievement) test with standard norms from a large standardization sample and satisfactory reliability estimates. Two test profiles of a Wernicke's aphasic, obtained before and after a 3-month period of speech therapy, are analyzed using inferential comparisons between (groups of) subtest scores on one test application and between two test administrations for single (groups of) subtests. For each of these comparisons, the two aspects of (i) significant (reliable) differences in performance beyond measurement error and (ii) the diagnostic validity of that difference in the reference population of aphasic patients are assessed. Significant differences between standardized subtest scores and a remarkably better preserved reading and writing ability could be found for both test administrations using the multiple test procedure of Holm (1979). Comparison of both profiles revealed an overall increase in performance for each subtest as well as changes in level of performance relations between pairs of subtests.
Pleiotropy Analysis of Quantitative Traits at Gene Level by Multivariate Functional Linear Models
Wang, Yifan; Liu, Aiyi; Mills, James L.; Boehnke, Michael; Wilson, Alexander F.; Bailey-Wilson, Joan E.; Xiong, Momiao; Wu, Colin O.; Fan, Ruzong
2015-01-01
In genetics, pleiotropy describes the genetic effect of a single gene on multiple phenotypic traits. A common approach is to analyze the phenotypic traits separately using univariate analyses and combine the test results through multiple comparisons. This approach may lead to low power. Multivariate functional linear models are developed to connect genetic variant data to multiple quantitative traits adjusting for covariates for a unified analysis. Three types of approximate F-distribution tests based on Pillai–Bartlett trace, Hotelling–Lawley trace, and Wilks’s Lambda are introduced to test for association between multiple quantitative traits and multiple genetic variants in one genetic region. The approximate F-distribution tests provide much more significant results than those of F-tests of univariate analysis and optimal sequence kernel association test (SKAT-O). Extensive simulations were performed to evaluate the false positive rates and power performance of the proposed models and tests. We show that the approximate F-distribution tests control the type I error rates very well. Overall, simultaneous analysis of multiple traits can increase power performance compared to an individual test of each trait. The proposed methods were applied to analyze (1) four lipid traits in eight European cohorts, and (2) three biochemical traits in the Trinity Students Study. The approximate F-distribution tests provide much more significant results than those of F-tests of univariate analysis and SKAT-O for the three biochemical traits. The approximate F-distribution tests of the proposed functional linear models are more sensitive than those of the traditional multivariate linear models that in turn are more sensitive than SKAT-O in the univariate case. The analysis of the four lipid traits and the three biochemical traits detects more association than SKAT-O in the univariate case. PMID:25809955
Pleiotropy analysis of quantitative traits at gene level by multivariate functional linear models.
Wang, Yifan; Liu, Aiyi; Mills, James L; Boehnke, Michael; Wilson, Alexander F; Bailey-Wilson, Joan E; Xiong, Momiao; Wu, Colin O; Fan, Ruzong
2015-05-01
In genetics, pleiotropy describes the genetic effect of a single gene on multiple phenotypic traits. A common approach is to analyze the phenotypic traits separately using univariate analyses and combine the test results through multiple comparisons. This approach may lead to low power. Multivariate functional linear models are developed to connect genetic variant data to multiple quantitative traits adjusting for covariates for a unified analysis. Three types of approximate F-distribution tests based on Pillai-Bartlett trace, Hotelling-Lawley trace, and Wilks's Lambda are introduced to test for association between multiple quantitative traits and multiple genetic variants in one genetic region. The approximate F-distribution tests provide much more significant results than those of F-tests of univariate analysis and optimal sequence kernel association test (SKAT-O). Extensive simulations were performed to evaluate the false positive rates and power performance of the proposed models and tests. We show that the approximate F-distribution tests control the type I error rates very well. Overall, simultaneous analysis of multiple traits can increase power performance compared to an individual test of each trait. The proposed methods were applied to analyze (1) four lipid traits in eight European cohorts, and (2) three biochemical traits in the Trinity Students Study. The approximate F-distribution tests provide much more significant results than those of F-tests of univariate analysis and SKAT-O for the three biochemical traits. The approximate F-distribution tests of the proposed functional linear models are more sensitive than those of the traditional multivariate linear models that in turn are more sensitive than SKAT-O in the univariate case. The analysis of the four lipid traits and the three biochemical traits detects more association than SKAT-O in the univariate case. © 2015 WILEY PERIODICALS, INC.
Braatne, Jeffrey H.; Goater, Lori A.; Blair, Charles L.
2007-01-01
River damming provides a dominant human impact on river environments worldwide, and while local impacts of reservoir flooding are immediate, subsequent ecological impacts downstream can be extensive. In this article, we assess seven research strategies for analyzing the impacts of dams and river flow regulation on riparian ecosystems. These include spatial comparisons of (1) upstream versus downstream reaches, (2) progressive downstream patterns, or (3) the dammed river versus an adjacent free-flowing or differently regulated river(s). Temporal comparisons consider (4) pre- versus post-dam, or (5) sequential post-dam conditions. However, spatial comparisons are complicated by the fact that dams are not randomly located, and temporal comparisons are commonly limited by sparse historic information. As a result, comparative approaches are often correlative and vulnerable to confounding factors. To complement these analyses, (6) flow or sediment modifications can be implemented to test causal associations. Finally, (7) process-based modeling represents a predictive approach incorporating hydrogeomorphic processes and their biological consequences. In a case study of Hells Canyon, the upstream versus downstream comparison is confounded by a dramatic geomorphic transition. Comparison of the multiple reaches below the dams should be useful, and the comparison of Snake River with the adjacent free-flowing Salmon River may provide the strongest spatial comparison. A pre- versus post-dam comparison would provide the most direct study approach, but pre-dam information is limited to historic reports and archival photographs. We conclude that multiple study approaches are essential to provide confident interpretations of ecological impacts downstream from dams, and propose a comprehensive study for Hells Canyon that integrates multiple research strategies. PMID:18043964
Evaluation of ames Multistix-SG for urine specific gravity versus refractometer specific gravity.
Adams, L J
1983-12-01
A comparison of urine specific gravity by a commercially available multiple reagent strip (Multistix-SG; Ames Division, Miles Laboratory) versus refractometer specific gravity (TS Meter; American Optical Corporation) was performed on 214 routine urine specimens. Agreement to +/- 0.005 was found in 72% of the specimens (r = 0.80). Urine specific gravity by the Multistix-SG showed a significant positive bias at urine pHs less than or equal to 6.0 and a negative bias at urine pHs greater than 7.0 in comparison to refractometer specific gravity. At concentrated (specific gravity greater than or equal to 1.020) specific gravities, up to 25% of urine specimens were misclassified as not concentrated by Multistix-SG specific gravity in comparison to refractometer specific gravity. The additional cost of the specific gravity reagent to a multiple reagent test strip in addition to the poor performance relative to refractometer specific gravity leads to the conclusion that including this specific gravity methodology on a multiple reagent strip is neither cost effective nor clinically useful.
Najafi, Mostafa; Akouchekian, Shahla; Ghaderi, Alireza; Mahaki, Behzad; Rezaei, Mariam
2017-01-01
Background: Attention deficit and hyperactivity disorder (ADHD) is a common psychological problem during childhood. This study aimed to evaluate multiple intelligences profiles of children with ADHD in comparison with non-ADHD. Materials and Methods: This cross-sectional descriptive analytical study was done on 50 children of 6–13 years old in two groups of with and without ADHD. Children with ADHD were referred to Clinics of Child and Adolescent Psychiatry, Isfahan University of Medical Sciences, in 2014. Samples were selected based on clinical interview (based on Diagnostic and Statistical Manual of Mental Disorders IV and parent–teacher strengths and difficulties questionnaire), which was done by psychiatrist and psychologist. Raven intelligence quotient (IQ) test was used, and the findings were compared to the results of multiple intelligences test. Data analysis was done using a multivariate analysis of covariance using SPSS20 software. Results: Comparing the profiles of multiple intelligence among two groups, there are more kinds of multiple intelligences in control group than ADHD group, a difference which has been more significant in logical, interpersonal, and intrapersonal intelligence (P < 0.05). There was no significant difference with the other kinds of multiple intelligences in two groups (P > 0.05). The IQ average score in the control group and ADHD group was 102.42 ± 16.26 and 96.72 ± 16.06, respectively, that reveals the negative effect of ADHD on IQ average value. There was an insignificance relationship between linguistic and naturalist intelligence (P > 0.05). However, in other kinds of multiple intelligences, direct and significant relationships were observed (P < 0.05). Conclusions: Since the levels of IQ (Raven test) and MI in control group were more significant than ADHD group, ADHD is likely to be associated with logical-mathematical, interpersonal, and intrapersonal profiles. PMID:29285478
Non-parametric combination and related permutation tests for neuroimaging.
Winkler, Anderson M; Webster, Matthew A; Brooks, Jonathan C; Tracey, Irene; Smith, Stephen M; Nichols, Thomas E
2016-04-01
In this work, we show how permutation methods can be applied to combination analyses such as those that include multiple imaging modalities, multiple data acquisitions of the same modality, or simply multiple hypotheses on the same data. Using the well-known definition of union-intersection tests and closed testing procedures, we use synchronized permutations to correct for such multiplicity of tests, allowing flexibility to integrate imaging data with different spatial resolutions, surface and/or volume-based representations of the brain, including non-imaging data. For the problem of joint inference, we propose and evaluate a modification of the recently introduced non-parametric combination (NPC) methodology, such that instead of a two-phase algorithm and large data storage requirements, the inference can be performed in a single phase, with reasonable computational demands. The method compares favorably to classical multivariate tests (such as MANCOVA), even when the latter is assessed using permutations. We also evaluate, in the context of permutation tests, various combining methods that have been proposed in the past decades, and identify those that provide the best control over error rate and power across a range of situations. We show that one of these, the method of Tippett, provides a link between correction for the multiplicity of tests and their combination. Finally, we discuss how the correction can solve certain problems of multiple comparisons in one-way ANOVA designs, and how the combination is distinguished from conjunctions, even though both can be assessed using permutation tests. We also provide a common algorithm that accommodates combination and correction. © 2016 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.
ERIC Educational Resources Information Center
Li, Hongli; Suen, Hoi K.
2015-01-01
This study examines how Chinese ESL learners recognize English words while responding to a multiple-choice reading test as compared to Romance-language-speaking ESL learners. Four adult Chinese ESL learners and three adult Romance-language-speaking ESL learners participated in a think-aloud study with the Michigan English Language Assessment…
An Empirical Comparison of Five Linear Equating Methods for the NEAT Design
ERIC Educational Resources Information Center
Suh, Youngsuk; Mroch, Andrew A.; Kane, Michael T.; Ripkey, Douglas R.
2009-01-01
In this study, a data base containing the responses of 40,000 candidates to 90 multiple-choice questions was used to mimic data sets for 50-item tests under the "nonequivalent groups with anchor test" (NEAT) design. Using these smaller data sets, we evaluated the performance of five linear equating methods for the NEAT design with five levels of…
A Comparison of Methods to Screen Middle School Students for Reading and Math Difficulties
ERIC Educational Resources Information Center
Nelson, Peter M.; Van Norman, Ethan R.; Lackner, Stacey K.
2016-01-01
The current study explored multiple ways in which middle schools can use and integrate data sources to predict proficiency on future high-stakes state achievement tests. The diagnostic accuracy of (a) prior achievement data, (b) teacher rating scale scores, (c) a composite score combining state test scores and rating scale responses, and (d) two…
2017-02-01
risks, by modeling thermal strain. Twenty clothing ensembles were tested for thermal and evaporative resistances according to American Society of...e.g., football, hockey, etc.) or during military, law enforcement, or first responder operations (e.g., body armor, flame resistant clothing, etc...Each clothing configuration was tested to American Society of Testing and Materials (ASTM) standards for “dry” thermal resistance (Rct) (ASTM F1291
Weber, M; Morgenthaler, M
1997-01-01
Are there any radiological criterions which are able to indicate the profession related disease No. 2108? The medical documents and x-rays of the whole spine of 390 back pain patients who applied for a profession related disease of the spine were evaluated. Those patients who fulfilled the professional claims for acknowledgement of the profession related disease were compared to those who didn't fulfill these conditions. Concerning the segmental alterations of the cervical and the lumbal spine specific allocation frequencies were found. The dominance of L3/4 in the comparison group was conspicuous. Looking at the allocation frequencies of the cervical and lumbal disc alterations in view of affection heaviness it was obvious, that the predominating slight alterations mainly were located in the central parts of the cervical and the lumbal spine whereas bad alterations mainly were found in the lower parts. Regarding this matter test and comparison groups behaved the same way. Looking at the allocation frequencies concerning single respectively multiple alterations it was found that in the comparison group single respectively bisegmentale alterations could be recognized even in duplicate than in the test group in which the multiple alterations were dominant. The comparison of the cervical and the lumbal spine regarding chondrotic? spondylotic, slight and bad alterations in all mentioned features the next deeper located segment was affected particularly in the test group. Therefore a distal shift of the chondrotic alterations could be recognized. In case of the spondylotic affections it was the other way round: a cranial shift was conspicuous. After doing heavy labour for years only a few isolated multiple affections of the lumbal spine are found. On the strength of this fact the proof of exclusively in the lumbal spine located alterations doesn't allow the acknowledgement of a profession related disease. However, a distal shift of osteochondrotic alterations respectively a cranial shift of spondylotic affections in the lumbal spine is suspicous for being job-related. L3/4 takes a very special place in the differential diagnosis of profession related disease of the spine. In the test group this part of the lumbal spine showed bad alterations much more frequent. The affection of L3/4 pleads against a considerable participation of mechanical influences and therefore against a profession related disease. Singular or bisegmental disc affections are out of question for being a profession related disease because these alterations are seen much more frequent in the comparison than in the test group.
ERIC Educational Resources Information Center
Woods, Carol M.; Cai, Li; Wang, Mian
2013-01-01
Differential item functioning (DIF) occurs when the probability of responding in a particular category to an item differs for members of different groups who are matched on the construct being measured. The identification of DIF is important for valid measurement. This research evaluates an improved version of Lord's chi [superscript 2]…
1993-09-01
34great man" (Bass & Stogdill,1990:37-38). Francis Galton in his book Hereditary Genius, maintains that the genius to which he refers is an expression of...to Test 14 Theorized Factors 85 Bibliography .............. ...................... .. 93 Vitae ......................... .................. 96 V List...FACTOR = NURTURING ........... ................ 68 26. PAIRED-T TEST RESULTS FOR EACH FACTOR ......... .. 69 27. BONFERRONI MULTIPLE COMPARISON BASED
Non‐parametric combination and related permutation tests for neuroimaging
Webster, Matthew A.; Brooks, Jonathan C.; Tracey, Irene; Smith, Stephen M.; Nichols, Thomas E.
2016-01-01
Abstract In this work, we show how permutation methods can be applied to combination analyses such as those that include multiple imaging modalities, multiple data acquisitions of the same modality, or simply multiple hypotheses on the same data. Using the well‐known definition of union‐intersection tests and closed testing procedures, we use synchronized permutations to correct for such multiplicity of tests, allowing flexibility to integrate imaging data with different spatial resolutions, surface and/or volume‐based representations of the brain, including non‐imaging data. For the problem of joint inference, we propose and evaluate a modification of the recently introduced non‐parametric combination (NPC) methodology, such that instead of a two‐phase algorithm and large data storage requirements, the inference can be performed in a single phase, with reasonable computational demands. The method compares favorably to classical multivariate tests (such as MANCOVA), even when the latter is assessed using permutations. We also evaluate, in the context of permutation tests, various combining methods that have been proposed in the past decades, and identify those that provide the best control over error rate and power across a range of situations. We show that one of these, the method of Tippett, provides a link between correction for the multiplicity of tests and their combination. Finally, we discuss how the correction can solve certain problems of multiple comparisons in one‐way ANOVA designs, and how the combination is distinguished from conjunctions, even though both can be assessed using permutation tests. We also provide a common algorithm that accommodates combination and correction. Hum Brain Mapp 37:1486‐1511, 2016. © 2016 Wiley Periodicals, Inc. PMID:26848101
Austin, Peter C; Mamdani, Muhammad M; Juurlink, David N; Hux, Janet E
2006-09-01
To illustrate how multiple hypotheses testing can produce associations with no clinical plausibility. We conducted a study of all 10,674,945 residents of Ontario aged between 18 and 100 years in 2000. Residents were randomly assigned to equally sized derivation and validation cohorts and classified according to their astrological sign. Using the derivation cohort, we searched through 223 of the most common diagnoses for hospitalization until we identified two for which subjects born under one astrological sign had a significantly higher probability of hospitalization compared to subjects born under the remaining signs combined (P<0.05). We tested these 24 associations in the independent validation cohort. Residents born under Leo had a higher probability of gastrointestinal hemorrhage (P=0.0447), while Sagittarians had a higher probability of humerus fracture (P=0.0123) compared to all other signs combined. After adjusting the significance level to account for multiple comparisons, none of the identified associations remained significant in either the derivation or validation cohort. Our analyses illustrate how the testing of multiple, non-prespecified hypotheses increases the likelihood of detecting implausible associations. Our findings have important implications for the analysis and interpretation of clinical studies.
Comparative study on collaborative interaction in non-immersive and immersive systems
NASA Astrophysics Data System (ADS)
Shahab, Qonita M.; Kwon, Yong-Moo; Ko, Heedong; Mayangsari, Maria N.; Yamasaki, Shoko; Nishino, Hiroaki
2007-09-01
This research studies the Virtual Reality simulation for collaborative interaction so that different people from different places can interact with one object concurrently. Our focus is the real-time handling of inputs from multiple users, where object's behavior is determined by the combination of the multiple inputs. Issues addressed in this research are: 1) The effects of using haptics on a collaborative interaction, 2) The possibilities of collaboration between users from different environments. We conducted user tests on our system in several cases: 1) Comparison between non-haptics and haptics collaborative interaction over LAN, 2) Comparison between non-haptics and haptics collaborative interaction over Internet, and 3) Analysis of collaborative interaction between non-immersive and immersive display environments. The case studies are the interaction of users in two cases: collaborative authoring of a 3D model by two users, and collaborative haptic interaction by multiple users. In Virtual Dollhouse, users can observe physics law while constructing a dollhouse using existing building blocks, under gravity effects. In Virtual Stretcher, multiple users can collaborate on moving a stretcher together while feeling each other's haptic motions.
Xu, Banglao; Du, Yan; Lin, Jinqiong; Qi, Mingyue; Shu, Bowen; Wen, Xiaoxia; Liang, Guangtie; Chen, Bin; Liu, Dayu
2016-12-06
A microfluidic chip was developed for one-step identification and antimicrobial susceptibility testing (AST) of multiple uropathogens. The polydimethylsiloxane (PDMS) microchip used had features of cell culture chamber arrays connected through a sample introduction channel. At the bottom of each chamber, a paper substrate preloaded with chromogenic media and antimicrobial agents was embedded. By integrating a hydrophobic membrane valve on the microchip, the urine sample can be equally distributed into and confined in individual chambers. The identification and AST assays on multiple uropathogens were performed by combining the spatial resolution of the cell culture arrays and the color resolution from the chromogenic reaction. The composite microbial testing assay was based on dynamic changes in color in a serial of chambers. The bacterial antimicrobial susceptibility was determined by the lowest concentration of an antimicrobial agent that is capable of inhibiting the chromogenic reaction. Using three common uropathogenic bacteria as test models, the developed microfluidic approach was demonstrated to be able to complete the multiple colorimetric assays in 15 h. The accuracy of the microchip method, in comparison with that of the conventional approach, showed a coincidence of 94.1%. Our data suggest this microfluidic approach will be a promising tool for simple and fast uropathogen testing in resource-limited settings.
Intersubject Differences in False Nonmatch Rates for a Fingerprint-Based Authentication System
NASA Astrophysics Data System (ADS)
Breebaart, Jeroen; Akkermans, Ton; Kelkboom, Emile
2009-12-01
The intersubject dependencies of false nonmatch rates were investigated for a minutiae-based biometric authentication process using single enrollment and verification measurements. A large number of genuine comparison scores were subjected to statistical inference tests that indicated that the number of false nonmatches depends on the subject and finger under test. This result was also observed if subjects associated with failures to enroll were excluded from the test set. The majority of the population (about 90%) showed a false nonmatch rate that was considerably smaller than the average false nonmatch rate of the complete population. The remaining 10% could be characterized as "goats due to their relatively high probability for a false nonmatch. The image quality reported by the template extraction module only weakly correlated with the genuine comparison scores. When multiple verification attempts were investigated, only a limited benefit was observed for "goats, since the conditional probability for a false nonmatch given earlier nonsuccessful attempts increased with the number of attempts. These observations suggest that (1) there is a need for improved identification of "goats during enrollment (e.g., using dedicated signal-driven analysis and classification methods and/or the use of multiple enrollment images) and (2) there should be alternative means for identity verification in the biometric system under test in case of two subsequent false nonmatches.
Weinberg, W A; McLean, A; Snider, R L; Rintelmann, J W; Brumback, R A
1989-12-01
Eight groups of learning disabled children (N = 100), categorized by the clinical Lexical Paradigm as good readers or poor readers, were individually administered the Gilmore Oral Reading Test, Form D, by one of four input/retrieval methods: (1) the standardized method of administration in which the child reads each paragraph aloud and then answers five questions relating to the paragraph [read/recall method]; (2) the child reads each paragraph aloud and then for each question selects the correct answer from among three choices read by the examiner [read/choice method]; (3) the examiner reads each paragraph aloud and reads each of the five questions to the child to answer [listen/recall method]; and (4) the examiner reads each paragraph aloud and then for each question reads three multiple-choice answers from which the child selects the correct answer [listen/choice method]. The major difference in scores was between the groups tested by the recall versus the orally read multiple-choice methods. This study indicated that poor readers who listened to the material and were tested by orally read multiple-choice format could perform as well as good readers. The performance of good readers was not affected by listening or by the method of testing. The multiple-choice testing improved the performance of poor readers independent of the input method. This supports the arguments made previously that a "bypass approach" to education of poor readers in which testing is accomplished using an orally read multiple-choice format can enhance the child's school performance on reading-related tasks. Using a listening while reading input method may further enhance performance.
Fast and Accurate Approximation to Significance Tests in Genome-Wide Association Studies
Zhang, Yu; Liu, Jun S.
2011-01-01
Genome-wide association studies commonly involve simultaneous tests of millions of single nucleotide polymorphisms (SNP) for disease association. The SNPs in nearby genomic regions, however, are often highly correlated due to linkage disequilibrium (LD, a genetic term for correlation). Simple Bonferonni correction for multiple comparisons is therefore too conservative. Permutation tests, which are often employed in practice, are both computationally expensive for genome-wide studies and limited in their scopes. We present an accurate and computationally efficient method, based on Poisson de-clumping heuristics, for approximating genome-wide significance of SNP associations. Compared with permutation tests and other multiple comparison adjustment approaches, our method computes the most accurate and robust p-value adjustments for millions of correlated comparisons within seconds. We demonstrate analytically that the accuracy and the efficiency of our method are nearly independent of the sample size, the number of SNPs, and the scale of p-values to be adjusted. In addition, our method can be easily adopted to estimate false discovery rate. When applied to genome-wide SNP datasets, we observed highly variable p-value adjustment results evaluated from different genomic regions. The variation in adjustments along the genome, however, are well conserved between the European and the African populations. The p-value adjustments are significantly correlated with LD among SNPs, recombination rates, and SNP densities. Given the large variability of sequence features in the genome, we further discuss a novel approach of using SNP-specific (local) thresholds to detect genome-wide significant associations. This article has supplementary material online. PMID:22140288
NASA Technical Reports Server (NTRS)
Deutschmann, Julie; Bar-Itzhack, Itzhack Y.; Rokni, Mohammad
1990-01-01
The testing and comparison of two Extended Kalman Filters (EKFs) developed for the Earth Radiation Budget Satellite (ERBS) is described. One EKF updates the attitude quaternion using a four component additive error quaternion. This technique is compared to that of a second EKF, which uses a multiplicative error quaternion. A brief development of the multiplicative algorithm is included. The mathematical development of the additive EKF was presented in the 1989 Flight Mechanics/Estimation Theory Symposium along with some preliminary testing results using real spacecraft data. A summary of the additive EKF algorithm is included. The convergence properties, singularity problems, and normalization techniques of the two filters are addressed. Both filters are also compared to those from the ERBS operational ground support software, which uses a batch differential correction algorithm to estimate attitude and gyro biases. Sensitivity studies are performed on the estimation of sensor calibration states. The potential application of the EKF for real time and non-real time ground attitude determination and sensor calibration for future missions such as the Gamma Ray Observatory (GRO) and the Small Explorer Mission (SMEX) is also presented.
Vegada, Bhavisha; Shukla, Apexa; Khilnani, Ajeetkumar; Charan, Jaykaran; Desai, Chetna
2016-01-01
Most of the academic teachers use four or five options per item of multiple choice question (MCQ) test as formative and summative assessment. Optimal number of options in MCQ item is a matter of considerable debate among academic teachers of various educational fields. There is a scarcity of the published literature regarding the optimum number of option in each item of MCQ in the field of medical education. To compare three options, four options, and five options MCQs test for the quality parameters - reliability, validity, item analysis, distracter analysis, and time analysis. Participants were 3 rd semester M.B.B.S. students. Students were divided randomly into three groups. Each group was given one set of MCQ test out of three options, four options, and five option randomly. Following the marking of the multiple choice tests, the participants' option selections were analyzed and comparisons were conducted of the mean marks, mean time, validity, reliability and facility value, discrimination index, point biserial value, distracter analysis of three different option formats. Students score more ( P = 0.000) and took less time ( P = 0.009) for the completion of three options as compared to four options and five options groups. Facility value was more ( P = 0.004) in three options group as compared to four and five options groups. There was no significant difference between three groups for the validity, reliability, and item discrimination. Nonfunctioning distracters were more in the four and five options group as compared to three option group. Assessment based on three option MCQs is can be preferred over four option and five option MCQs.
Idiopathic hypersomnia: a study of 77 cases.
Anderson, Kirstie N; Pilsworth, Samantha; Sharples, Linda D; Smith, Ian E; Shneerson, John M
2007-10-01
To review the clinical and polysomnographic characteristics of idiopathic hypersomnia as well as the long-term response to treatment. The Respiratory Support and Sleep Centre at Papworth Hospital, Cambridge, UK. A large database of more than 6000 patients with sleep disorders was reviewed. A retrospective study of the clinical and polysomnographic characteristics of 77 patients with idiopathic hypersomnia was performed. Comparison with a similar group of patients with narcolepsy was performed. The response to drug treatment was assessed in 61 patients over a mean follow-up of 3.8 years. Idiopathic hypersomnia was 60% as prevalent as narcolepsy. Comparison with a similar group of patients with narcolepsy showed that those with idiopathic hypersomnia were more likely to have prolonged unrefreshing daytime naps, a positive family history, increased slow-wave sleep, and a longer sleep latency on the Multiple Sleep Latency Test. The results of the Multiple Sleep Latency Test were not helpful in predicting disease severity or treatment response. The clinical features were heterogeneous and of variable severity. The majority of patients with idiopathic hypersomnia had symptoms that remained stable over many years, but 11% had spontaneous remission, which was never seen in narcolepsy. Two thirds of patients with idiopathic hypersomnolence had a sustained improvement in daytime somnolence with medication, although a third needed high doses or combinations of drugs. Idiopathic hypersomnolence has characteristic clinical and polysomnographic features but the prolonged latency on the Multiple Sleep Latency Test raises doubt about the validity of this test within the current diagnostic criteria. The disease often responds well to treatment and a substantial minority of patients appear to spontaneously improve.
2016-09-01
by DOD to further develop and test protein delivery for the retina. Ongoing Research Support W81XWH-16-1-0650 09/30/16-09/29/19 U.S...Medical Research Institute to test small molecules for inhibition of MAC in laser induced choroidal neovascularization PI Robert Liddington; No...streptavidin594 conjugation and dosing studies. Bonferroni’s multiple comparison tests were used for Post hoc analysis. One-way analysis of variance
2007-05-01
and post - synaptic dopamine biosynthesis, uptake and receptor expression as well as glutamatergic synapses. This hypothesis will be tested through...0.05) compared to mice at 7 days (9.6 ± 3.2%) or 30 days post -MPTP (16.5 ± 7.3%). The tail suspension test showed a significant increase in percent of...were compared using one-way analysis of variance (ANOVA), followed by the Fisher post hoc test for comparison of multiple means for the following
Long-Term Effect of Prefrontal Lobotomy on Verbal Fluency in Patients with Schizophrenia
ERIC Educational Resources Information Center
Stip, Emmanuel; Bigras, Marie-Josee.; Mancini-Marie, Adham; Cosset, Marie-Eve.; Black, Deborah; Lecours, Andre-Roch
2004-01-01
Objective: This study investigated the long-term effects of bilateral prefrontal leukotomy on lexical abilities in schizophrenia subjects. Method: We compared performances of leukotomized (LSP), non-leukotomized schizophrenia patients (NLSP) and normal controls, using a test of verbal fluency. Multiple case and triple comparison design were…
A pilot-scale field experiment was conducted to compare the remediation effectiveness of an enhanced-solubilization technique to that of water flushing for removal of multicomponent nonaqueous-phase organic liquid (NAPL) contaminants form a phreatic aquifer. This innovative remed...
Ateş, Aşkin; Kinikli, Gülay; Turgay, Murat; Aydoğan, Nergis; Duman, Murat
2004-01-01
Skin prick testing (SPT) is widely used in the assessment of allergic disorders. Different SPT techniques are widely used. The aim of this study was to compare the response to SPT using a multiple lancet device (MLD) with the results of a single lancet (SL). Fifty patients with allergic rhinitis were included in this study. Initially, SPT was performed by a SL technique. After one week SPT was repeated using the MLD on all patients. The patients were tested with a panel containing 19 specific allergens including grass pollen, tree pollen, house dust mites, weed pollen allergen extracts, histamine and a negative control. The skin responses were recorded after 15 minutes for each device by measuring the diameter of the wheal and the erythema. The skin wheal responses for grass pollen, tree pollen, weed pollen and house dust mite allergen extracts obtained using the SL were generally significantly larger than those using the MLD. The comparison between the MLD and the SL methods revealed that SPT was positive with SL and negative with MLD in 176 tests (15.3%), and on the contrary SPT was positive with MLD and negative with SL in only 13 tests (1%). In conclusion, we claim that SPT using SL shows a higher degree of sensitivity and reproducibility.
SPICE: exploration and analysis of post-cytometric complex multivariate datasets.
Roederer, Mario; Nozzi, Joshua L; Nason, Martha C
2011-02-01
Polychromatic flow cytometry results in complex, multivariate datasets. To date, tools for the aggregate analysis of these datasets across multiple specimens grouped by different categorical variables, such as demographic information, have not been optimized. Often, the exploration of such datasets is accomplished by visualization of patterns with pie charts or bar charts, without easy access to statistical comparisons of measurements that comprise multiple components. Here we report on algorithms and a graphical interface we developed for these purposes. In particular, we discuss thresholding necessary for accurate representation of data in pie charts, the implications for display and comparison of normalized versus unnormalized data, and the effects of averaging when samples with significant background noise are present. Finally, we define a statistic for the nonparametric comparison of complex distributions to test for difference between groups of samples based on multi-component measurements. While originally developed to support the analysis of T cell functional profiles, these techniques are amenable to a broad range of datatypes. Published 2011 Wiley-Liss, Inc.
NASA Technical Reports Server (NTRS)
Durston, Donald A.; Kmak, Francis J.
2009-01-01
Multiple sonic boom wind tunnel models were tested in the NASA Ames Research Center 9-by 7-Foot Supersonic Wind Tunnel to reestablish related test techniques in this facility. The goal of the testing was to acquire higher fidelity sonic boom signatures with instrumentation that is significantly more sensitive than that used during previous wind tunnel entries and to compare old and new data from established models. Another objective was to perform tunnel-to-tunnel comparisons of data from a Gulfstream sonic boom model tested at the NASA Langley Research Center 4-foot by 4-foot Unitary Plan Wind Tunnel.
A clinical test of stepping and change of direction to identify multiple falling older adults.
Dite, Wayne; Temple, Viviene A
2002-11-01
To establish the reliability and validity of a new clinical test of dynamic standing balance, the Four Square Step Test (FSST), to evaluate its sensitivity, specificity, and predictive value in identifying subjects who fall, and to compare it with 3 established balance and mobility tests. A 3-group comparison performed by using 3 validated tests and 1 new test. A rehabilitation center and university medical school in Australia. Eighty-one community-dwelling adults over the age of 65 years. Subjects were age- and gender-matched to form 3 groups: multiple fallers, nonmultiple fallers, and healthy comparisons. Not applicable. Time to complete the FSST and Timed Up and Go test and the number of steps to complete the Step Test and Functional Reach Test distance. High reliability was found for interrater (n=30, intraclass correlation coefficient [ICC]=.99) and retest reliability (n=20, ICC=.98). Evidence for validity was found through correlation with other existing balance tests. Validity was supported, with the FSST showing significantly better performance scores (P<.01) for each of the healthier and less impaired groups. The FSST also revealed a sensitivity of 85%, a specificity of 88% to 100%, and a positive predictive value of 86%. As a clinical test, the FSST is reliable, valid, easy to score, quick to administer, requires little space, and needs no special equipment. It is unique in that it involves stepping over low objects (2.5cm) and movement in 4 directions. The FSST had higher combined sensitivity and specificity for identifying differences between groups in the selected sample population of older adults than the 3 tests with which it was compared. Copyright 2002 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation
Influence of selected test parameters on measured values during the MSCR test
NASA Astrophysics Data System (ADS)
Benešová, Lucie; Valentin, Jan
2017-09-01
One of today’s most commonly used test on a Dynamic Shear Rheometer (DSR) is the Multiple Stress Creep Recovery (MSCR) test. The test is described in the standard EN 16659, which is valid in the Czech Republic since October 2016. The principle of the test is based on repeated loading and recovering of a bitumen sample, according to which it is possible to determine the percentage of elastic recovery (R) and non-recoverable creep compliance (Jnr) of the bituminous binder. This method has been recently promoted as the most suitable test for assessing the resistance of bituminous binders to permanent deformation. The test is performed at higher temperatures and is particularly suitable for modified bituminous binders. The paper deals with the comparison of the different input parameters set on the DSR device - different levels of stress, temperature of test, the geometry of the measuring device and also a comparison of the results for a different number of loading cycles. The research study was focused mainly on modified bituminous binders, but to compare the MSCR test it is performed even with conventional paving grade binders.
Chen, Xiwei; Yu, Jihnhee
2014-01-01
Abstract Many clinical and biomedical studies evaluate treatment effects based on multiple biomarkers that commonly consist of pre- and post-treatment measurements. Some biomarkers can show significant positive treatment effects, while other biomarkers can reflect no effects or even negative effects of the treatments, giving rise to a necessity to develop methodologies that may correctly and efficiently evaluate the treatment effects based on multiple biomarkers as a whole. In the setting of pre- and post-treatment measurements of multiple biomarkers, we propose to apply a receiver operating characteristic (ROC) curve methodology based on the best combination of biomarkers maximizing the area under the receiver operating characteristic curve (AUC)-type criterion among all possible linear combinations. In the particular case with independent pre- and post-treatment measurements, we show that the proposed method represents the well-known Su and Liu's (1993) result. Further, proceeding from derived best combinations of biomarkers' measurements, we propose an efficient technique via likelihood ratio tests to compare treatment effects. We show an extensive Monte Carlo study that confirms the superiority of the proposed test in comparison with treatment effects based on multiple biomarkers in a paired data setting. For practical applications, the proposed method is illustrated with a randomized trial of chlorhexidine gluconate on oral bacterial pathogens in mechanically ventilated patients as well as a treatment study for children with attention deficit-hyperactivity disorder and severe mood dysregulation. PMID:25019920
NASA Astrophysics Data System (ADS)
Haydel, Angela Michelle
The purpose of this dissertation was to advance theoretical understanding about fit between the personal resources of individuals and the characteristics of science achievement tasks. Testing continues to be pervasive in schools, yet we know little about how students perceive tests and what they think and feel while they are actually working on test items. This study focused on both the personal (cognitive and motivational) and situational factors that may contribute to individual differences in achievement-related outcomes. 387 eighth grade students first completed a survey including measures of science achievement goals, capability beliefs, efficacy related to multiple-choice items and performance assessments, validity beliefs about multiple-choice items and performance assessments, and other perceptions of these item formats. Students then completed science achievement tests including multiple-choice items and two performance assessments. A sample of students was asked to verbalize both thoughts and feelings as they worked through the test items. These think-alouds were transcribed and coded for evidence of cognitive, metacognitive and motivational engagement. Following each test, all students completed measures of effort, mood, energy level and strategy use during testing. Students reported that performance assessments were more challenging, authentic, interesting and valid than multiple-choice tests. They also believed that comparisons between students were easier using multiple-choice items. Overall, students tried harder, felt better, had higher levels of energy and used more strategies while working on performance assessments. Findings suggested that performance assessments might be more congruent with a mastery achievement goal orientation, while multiple-choice tests might be more congruent with a performance achievement goal orientation. A variable-centered analytic approach including regression analyses provided information about how students, on average, who differed in terms of their teachers' ratings of their science ability, achievement goals, capability beliefs and experiences with science achievement tasks perceived, engaged in, and performed on multiple-choice items and performance assessments. Person-centered analyses provided information about the perceptions, engagement and performance of subgroups of individuals who had different motivational characteristics. Generally, students' personal goals and capability beliefs related more strongly to test perceptions, but not performance, while teacher ratings of ability and test-specific beliefs related to performance.
Kuiper, Gerhardus J A J M; Houben, Rik; Wetzels, Rick J H; Verhezen, Paul W M; Oerle, Rene van; Ten Cate, Hugo; Henskens, Yvonne M C; Lancé, Marcus D
2017-11-01
Low platelet counts and hematocrit levels hinder whole blood point-of-care testing of platelet function. Thus far, no reference ranges for MEA (multiple electrode aggregometry) and PFA-100 (platelet function analyzer 100) devices exist for low ranges. Through dilution methods of volunteer whole blood, platelet function at low ranges of platelet count and hematocrit levels was assessed on MEA for four agonists and for PFA-100 in two cartridges. Using (multiple) regression analysis, 95% reference intervals were computed for these low ranges. Low platelet counts affected MEA in a positive correlation (all agonists showed r 2 ≥ 0.75) and PFA-100 in an inverse correlation (closure times were prolonged with lower platelet counts). Lowered hematocrit did not affect MEA testing, except for arachidonic acid activation (ASPI), which showed a weak positive correlation (r 2 = 0.14). Closure time on PFA-100 testing was inversely correlated with hematocrit for both cartridges. Regression analysis revealed different 95% reference intervals in comparison with originally established intervals for both MEA and PFA-100 in low platelet or hematocrit conditions. Multiple regression analysis of ASPI and both tests on the PFA-100 for combined low platelet and hematocrit conditions revealed that only PFA-100 testing should be adjusted for both thrombocytopenia and anemia. 95% reference intervals were calculated using multiple regression analysis. However, coefficients of determination of PFA-100 were poor, and some variance remained unexplained. Thus, in this pilot study using (multiple) regression analysis, we could establish reference intervals of platelet function in anemia and thrombocytopenia conditions on PFA-100 and in thrombocytopenia conditions on MEA.
ERIC Educational Resources Information Center
Gkouvatzi, Anastasia N.; Mantis, Konstantinos; Kambas, Antonis
2010-01-01
Using the Bruininks-Oseretsky Test the motor performance of 34 deaf--hard-of-hearing pupils, 6-14 year, was evaluated in reaction time, visual-motor control and upper limb speed and dexterity. The two-way ANOVA variance analysis for two independent variables, group, age, and the Post Hoc (Scheffe test) for multiple comparisons were used. The…
Effects of Imperfect Automation on Operator’s Supervisory Control of Multiple Robots
2011-08-01
7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) U.S. Army Research Laboratory ATTN: RDRL- HRM -AT Aberdeen Proving Ground, MD 21005-5425 8...Survey, the Ishihara Color Vision Test, and the Cube 6 Comparison test. Participants then received training and practice on the tasks they were about to...completing various tasks, several mini- exercises for practicing the steps, and exercises for performing the robotic control tasks. The type and
NASA Astrophysics Data System (ADS)
Dhitareka, P. H.; Firman, H.; Rusyati, L.
2018-05-01
This research is comparing science virtual and paper-based test in measuring grade 7 students’ critical thinking based on Multiple Intelligences and gender. Quasi experimental method with within-subjects design is conducted in this research in order to obtain the data. The population of this research was all seventh grade students in ten classes of one public secondary school in Bandung. There were 71 students within two classes taken randomly became the sample in this research. The data are obtained through 28 questions with a topic of living things and environmental sustainability constructed based on eight critical thinking elements proposed by Inch then the questions provided in science virtual and paper-based test. The data was analysed by using paired-samples t test when the data are parametric and Wilcoxon signed ranks test when the data are non-parametric. In general comparison, the p-value of the comparison between science virtual and paper-based tests’ score is 0.506, indicated that there are no significance difference between science virtual and paper-based test based on the tests’ score. The results are furthermore supported by the students’ attitude result which is 3.15 from the scale from 1 to 4, indicated that they have positive attitudes towards Science Virtual Test.
A Systematic Analysis of 2 Monoisocentric Techniques for the Treatment of Multiple Brain Metastases.
Narayanasamy, Ganesh; Stathakis, Sotirios; Gutierrez, Alonso N; Pappas, Evangelos; Crownover, Richard; Floyd, John R; Papanikolaou, Niko
2017-10-01
In this treatment planning study, we compare the plan quality and delivery parameters for the treatment of multiple brain metastases using 2 monoisocentric techniques: the Multiple Metastases Element from Brainlab and the RapidArc volumetric-modulated arc therapy from Varian Medical Systems. Eight patients who were treated in our institution for multiple metastases (3-7 lesions) were replanned with Multiple Metastases Element using noncoplanar dynamic conformal arcs. The same patients were replanned with the RapidArc technique in Eclipse using 4 noncoplanar arcs. Both techniques were designed using a single isocenter. Plan quality metrics (conformity index, homogeneity index, gradient index, and R 50% ), monitor unit, and the planning time were recorded. Comparison of the Multiple Metastases Element and RapidArc plans was performed using Shapiro-Wilk test, paired Student t test, and Wilcoxon signed rank test. A paired Wilcoxon signed rank test between Multiple Metastases Element and RapidArc showed comparable plan quality metrics and dose to brain. Mean ± standard deviation values of conformity index were 1.8 ± 0.7 and 1.7 ± 0.6, homogeneity index were 1.3 ± 0.1 and 1.3 ± 0.1, gradient index were 5.0 ± 1.8 and 5.1 ± 1.9, and R 50% were 4.9 ± 1.8 and 5.0 ± 1.9 for Multiple Metastases Element and RapidArc plans, respectively. Mean brain dose was 2.3 and 2.7 Gy for Multiple Metastases Element and RapidArc plans, respectively. The mean value of monitor units in Multiple Metastases Element plan was 7286 ± 1065, which is significantly lower than the RapidArc monitor units of 9966 ± 1533 ( P < .05). For the planning of multiple brain lesions to be treated with stereotactic radiosurgery, Multiple Metastases Element planning software produced equivalent conformity, homogeneity, dose falloff, and brain V 12 Gy but required significantly lower monitor units, when compared to RapidArc plans.
A Systematic Analysis of 2 Monoisocentric Techniques for the Treatment of Multiple Brain Metastases
Stathakis, Sotirios; Gutierrez, Alonso N.; Pappas, Evangelos; Crownover, Richard; Floyd, John R.; Papanikolaou, Niko
2016-01-01
Background: In this treatment planning study, we compare the plan quality and delivery parameters for the treatment of multiple brain metastases using 2 monoisocentric techniques: the Multiple Metastases Element from Brainlab and the RapidArc volumetric-modulated arc therapy from Varian Medical Systems. Methods: Eight patients who were treated in our institution for multiple metastases (3-7 lesions) were replanned with Multiple Metastases Element using noncoplanar dynamic conformal arcs. The same patients were replanned with the RapidArc technique in Eclipse using 4 noncoplanar arcs. Both techniques were designed using a single isocenter. Plan quality metrics (conformity index, homogeneity index, gradient index, and R50%), monitor unit, and the planning time were recorded. Comparison of the Multiple Metastases Element and RapidArc plans was performed using Shapiro-Wilk test, paired Student t test, and Wilcoxon signed rank test. Results: A paired Wilcoxon signed rank test between Multiple Metastases Element and RapidArc showed comparable plan quality metrics and dose to brain. Mean ± standard deviation values of conformity index were 1.8 ± 0.7 and 1.7 ± 0.6, homogeneity index were 1.3 ± 0.1 and 1.3 ± 0.1, gradient index were 5.0 ± 1.8 and 5.1 ± 1.9, and R50% were 4.9 ± 1.8 and 5.0 ± 1.9 for Multiple Metastases Element and RapidArc plans, respectively. Mean brain dose was 2.3 and 2.7 Gy for Multiple Metastases Element and RapidArc plans, respectively. The mean value of monitor units in Multiple Metastases Element plan was 7286 ± 1065, which is significantly lower than the RapidArc monitor units of 9966 ± 1533 (P < .05). Conclusion: For the planning of multiple brain lesions to be treated with stereotactic radiosurgery, Multiple Metastases Element planning software produced equivalent conformity, homogeneity, dose falloff, and brain V12 Gy but required significantly lower monitor units, when compared to RapidArc plans. PMID:27612917
Solidification/stabilization (S/S) technology is widely used in the treatment of hazardous waste and contaminated soil in the US. In a project sponsored by the US Navy and the USEPA, treatability test data were compiled into a data base listing contaminant concentration and matri...
Daniel R. Miller; B. Staffan Lindgren
2000-01-01
Multiple-funnel traps baited with exo-brevicomin and a mixture of cis- and trans-verbenol were used to test the relative attractiveness of myrcene and (-)-a -pinene to the mountain pine beetle, Dendroctonus ponderosae Hopkins, in a stand...
Teaching Mathematics by Comparison: Analog Visibility as a Double-Edged Sword
ERIC Educational Resources Information Center
Begolli, Kreshnik Nasi; Richland, Lindsey Engle
2016-01-01
Comparing multiple solutions to a single problem is an important mode for developing flexible mathematical thinking, yet instructionally leading this activity is challenging (Stein, Engle, Smith, & Hughes, 2008). We test 1 decision teachers must make after having students solve a problem: whether to only verbally discuss students' solutions or…
Measuring Social Support and School Belonging in Black/African American and White Children
ERIC Educational Resources Information Center
Wegmann, Kate M.
2017-01-01
Objective: To determine the suitability of the Elementary School Success Profile for Children (ESSP-C) for assessment and comparison of social support and school belonging between Black/African American and White students. Methods: Multiple-group confirmatory factor analysis and invariance testing were conducted to determine the ESSP-C's validity…
Predicting End-of-Year Achievement Test Performance: A Comparison of Assessment Methods
ERIC Educational Resources Information Center
Kettler, Ryan J.; Elliott, Stephen N.; Kurz, Alexander; Zigmond, Naomi; Lemons, Christopher J.; Kloo, Amanda; Shrago, Jacqueline; Beddow, Peter A.; Williams, Leila; Bruen, Charles; Lupp, Lynda; Farmer, Jeanie; Mosiman, Melanie
2014-01-01
Motivated by the multiple-measures clause of recent federal policy regarding student eligibility for alternate assessments based on modified academic achievement standards (AA-MASs), this study examined how scores or combinations of scores from a diverse set of assessments predicted students' end-of-year proficiency status on statewide achievement…
Zhang, Dake; Stecker, Pamela; Huckabee, Sloan; Miller, Rhonda
2016-09-01
Research has suggested that different strategies used when solving fraction problems are highly correlated with students' problem-solving accuracy. This study (a) utilized latent profile modeling to classify students into three different strategic developmental levels in solving fraction comparison problems and (b) accordingly provided differentiated strategic training for students starting from two different strategic developmental levels. In Study 1 we assessed 49 middle school students' performance on fraction comparison problems and categorized students into three clusters of strategic developmental clusters: a cross-multiplication cluster with the highest accuracy, a representation strategy cluster with medium accuracy, and a whole-number strategy cluster with the lowest accuracy. Based on the strategic developmental levels identified in Study 1, in Study 2 we selected three students from the whole-number strategy cluster and another three students from the representation strategy cluster and implemented a differentiated strategic training intervention within a multiple-baseline design. Results showed that both groups of students transitioned from less advanced to more advanced strategies and improved their problem-solving accuracy during the posttest, the maintenance test, and the generalization test. © Hammill Institute on Disabilities 2014.
Why We (Usually) Don't Have to Worry about Multiple Comparisons
ERIC Educational Resources Information Center
Gelman, Andrew; Hill, Jennifer; Yajima, Masanao
2012-01-01
Applied researchers often find themselves making statistical inferences in settings that would seem to require multiple comparisons adjustments. We challenge the Type I error paradigm that underlies these corrections. Moreover we posit that the problem of multiple comparisons can disappear entirely when viewed from a hierarchical Bayesian…
Construct and Compare Gene Coexpression Networks with DAPfinder and DAPview.
Skinner, Jeff; Kotliarov, Yuri; Varma, Sudhir; Mine, Karina L; Yambartsev, Anatoly; Simon, Richard; Huyen, Yentram; Morgun, Andrey
2011-07-14
DAPfinder and DAPview are novel BRB-ArrayTools plug-ins to construct gene coexpression networks and identify significant differences in pairwise gene-gene coexpression between two phenotypes. Each significant difference in gene-gene association represents a Differentially Associated Pair (DAP). Our tools include several choices of filtering methods, gene-gene association metrics, statistical testing methods and multiple comparison adjustments. Network results are easily displayed in Cytoscape. Analyses of glioma experiments and microarray simulations demonstrate the utility of these tools. DAPfinder is a new friendly-user tool for reconstruction and comparison of biological networks.
Detection of faults and software reliability analysis
NASA Technical Reports Server (NTRS)
Knight, J. C.
1986-01-01
Multiversion or N-version programming was proposed as a method of providing fault tolerance in software. The approach requires the separate, independent preparation of multiple versions of a piece of software for some application. Specific topics addressed are: failure probabilities in N-version systems, consistent comparison in N-version systems, descriptions of the faults found in the Knight and Leveson experiment, analytic models of comparison testing, characteristics of the input regions that trigger faults, fault tolerance through data diversity, and the relationship between failures caused by automatically seeded faults.
Experimental problem solving: An instructional improvement field experiment
NASA Astrophysics Data System (ADS)
Ross, John A.; Maynes, Florence J.
An instructional program based on expert-novice differences in experimental problem-solving performance was taught to grade 6 students (N = 265). Classes of students were randomly assigned to conditions in a delayed treatment design. Performance was assessed with multiple-choice and open-ended measures of specific transfer. Between group comparisons using pretest scores as a covariate showed that treatment condition students consistently outperformed controls; similar results were revealed in the within group comparisons. The achievement of the early treatment group did not decline in tests administered one month after the posttest.
Korotcov, Alexandru; Tkachenko, Valery; Russo, Daniel P; Ekins, Sean
2017-12-04
Machine learning methods have been applied to many data sets in pharmaceutical research for several decades. The relative ease and availability of fingerprint type molecular descriptors paired with Bayesian methods resulted in the widespread use of this approach for a diverse array of end points relevant to drug discovery. Deep learning is the latest machine learning algorithm attracting attention for many of pharmaceutical applications from docking to virtual screening. Deep learning is based on an artificial neural network with multiple hidden layers and has found considerable traction for many artificial intelligence applications. We have previously suggested the need for a comparison of different machine learning methods with deep learning across an array of varying data sets that is applicable to pharmaceutical research. End points relevant to pharmaceutical research include absorption, distribution, metabolism, excretion, and toxicity (ADME/Tox) properties, as well as activity against pathogens and drug discovery data sets. In this study, we have used data sets for solubility, probe-likeness, hERG, KCNQ1, bubonic plague, Chagas, tuberculosis, and malaria to compare different machine learning methods using FCFP6 fingerprints. These data sets represent whole cell screens, individual proteins, physicochemical properties as well as a data set with a complex end point. Our aim was to assess whether deep learning offered any improvement in testing when assessed using an array of metrics including AUC, F1 score, Cohen's kappa, Matthews correlation coefficient and others. Based on ranked normalized scores for the metrics or data sets Deep Neural Networks (DNN) ranked higher than SVM, which in turn was ranked higher than all the other machine learning methods. Visualizing these properties for training and test sets using radar type plots indicates when models are inferior or perhaps over trained. These results also suggest the need for assessing deep learning further using multiple metrics with much larger scale comparisons, prospective testing as well as assessment of different fingerprints and DNN architectures beyond those used.
Cartier, Vanessa; Inan, Cigdem; Zingg, Walter; Delhumeau, Cecile; Walder, Bernard; Savoldelli, Georges L
2016-08-01
Multimodal educational interventions have been shown to improve short-term competency in, and knowledge of central venous catheter (CVC) insertion. To evaluate the effectiveness of simulation-based medical education training in improving short and long-term competency in, and knowledge of CVC insertion. Before and after intervention study. University Geneva Hospital, Geneva, Switzerland, between May 2008 and January 2012. Residents in anaesthesiology aware of the Seldinger technique for vascular puncture. Participants attended a half-day course on CVC insertion. Learning objectives included work organization, aseptic technique and prevention of CVC complications. CVC insertion competency was tested pretraining, posttraining and then more than 2 years after training (sustainability phase). The primary study outcome was competency as measured by a global rating scale of technical skills, a hand hygiene compliance score and a checklist compliance score. Secondary outcome was knowledge as measured by a standardised pretraining and posttraining multiple-choice questionnaire. Statistical analyses were performed using paired Student's t test or Wilcoxon signed-rank test. Thirty-seven residents were included; 18 were tested in the sustainability phase (on average 34 months after training). The average global rating of skills was 23.4 points (±SD 4.08) before training, 32.2 (±4.51) after training (P < 0.001 for comparison with pretraining scores) and 26.5 (±5.34) in the sustainability phase (P = 0.040 for comparison with pretraining scores). The average hand hygiene compliance score was 2.8 (±1.0) points before training, 5.0 (±1.04) after training (P < 0.001 for comparison with pretraining scores) and 3.7 (±1.75) in the sustainability phase (P = 0.038 for comparison with pretraining scores). The average checklist compliance was 14.9 points (±2.3) before training, 19.9 (±1.06) after training (P < 0.001 for comparison with pretraining scores) and 17.4 (±1.41) (P = 0.002 for comparison with pretraining scores). The percentage of correct answers in the multiple-choice questionnaire increased from 76.0% (±7.9) before training to 87.7% (±4.4) after training (P < 0.001). Simulation-based medical education training was effective in improving short and long-term competency in, and knowledge of CVC insertion.
Hayes, Brenna; Hassed, Susan; Chaloner, Jae Lindsay; Aston, Christopher E; Guy, Carrie
2016-06-01
Carrier testing is widely available for multiple genetic conditions, and several professional organizations have created practice guidelines regarding appropriate clinical application and the testing of minors. Previous research has focused on carrier screening, predictive testing, and testing for X-linked conditions. However, family perspectives on carrier testing for X-linked lethal diseases have yet to be described. In this study, we explored communication within the family about carrier testing and the perspectives of mothers of sons with an X-linked lethal disease, Duchenne muscular dystrophy (DMD). Twenty-five mothers of sons with DMD participated in an anonymous online survey. Survey questions included multiple choice, Likert scale, and open ended, short answer questions. Analysis of the multiple choice and Likert scale questions revealed that most mothers preferred a gradual style of communication with their daughters regarding risk status. In addition, most participants reported having consulted with a genetic counselor and found it helpful. Comparisons between groups, analyzed using Fisher's exact tests, found no differences in preferred style due to mother's carrier status or having a daughter. Thematic analysis was conducted on responses to open ended questions. Themes identified included the impact of family implications, age and maturity, and a desire for autonomy regarding the decision to discuss and undergo carrier testing with at-risk daughters, particularly timing of these discussions. Implications for genetic counseling practice are discussed.
Idiopathic Hypersomnia: A Study of 77 Cases
Anderson, Kirstie N.; Pilsworth, Samantha; Sharples, Linda D.; Smith, Ian E.; Shneerson, John M.
2007-01-01
Study Objectives: To review the clinical and polysomnographic characteristics of idiopathic hypersomnia as well as the long-term response to treatment. Setting: The Respiratory Support and Sleep Centre at Papworth Hospital, Cambridge, UK. Patients and Design: A large database of more than 6000 patients with sleep disorders was reviewed. A retrospective study of the clinical and polysomnographic characteristics of 77 patients with idiopathic hypersomnia was performed. Comparison with a similar group of patients with narcolepsy was performed. The response to drug treatment was assessed in 61 patients over a mean follow-up of 3.8 years. Measurements and Results: Idiopathic hypersomnia was 60% as prevalent as narcolepsy. Comparison with a similar group of patients with narcolepsy showed that those with idiopathic hypersomnia were more likely to have prolonged unrefreshing daytime naps, a positive family history, increased slow-wave sleep, and a longer sleep latency on the Multiple Sleep Latency Test. The results of the Multiple Sleep Latency Test were not helpful in predicting disease severity or treatment response. The clinical features were heterogeneous and of variable severity. The majority of patients with idiopathic hypersomnia had symptoms that remained stable over many years, but 11% had spontaneous remission, which was never seen in narcolepsy. Two thirds of patients with idiopathic hypersomnolence had a sustained improvement in daytime somnolence with medication, although a third needed high doses or combinations of drugs. Conclusions: Idiopathic hypersomnolence has characteristic clinical and polysomnographic features but the prolonged latency on the Multiple Sleep Latency Test raises doubt about the validity of this test within the current diagnostic criteria. The disease often responds well to treatment and a substantial minority of patients appear to spontaneously improve. Citation: Anderson KN; Pilsworth S; Sharples LD; Smith IE; Shneerson JM. Idiopathic hypersomnia: a study of 77 cases. SLEEP 2007;30(10):1274-1281. PMID:17969461
Comparison of Experimental and Analytical Tooth Bending Stress of Aerospace Spiral Bevel Gears
NASA Technical Reports Server (NTRS)
Handschuh, Robert F.; Bibel, George D.
1999-01-01
An experimental study to investigate the bending stress in aerospace-quality spiral bevel gears was performed. Tests were conducted in the NASA Lewis Spiral Bevel Gear Test Facility. Multiple teeth on the spiral bevel pinion were instrumented with strain gages and tests were conducted from static (slow roll) to 14400 RPM at power levels to 540kW (720 hp). Effects of changing speed and load on the bending stress were measured. Experimental results are compared to those found by three-dimensional finite element analysis.
Development of a MEMS device for acoustic emission testing
NASA Astrophysics Data System (ADS)
Ozevin, Didem; Pessiki, Stephen P.; Jain, Akash; Greve, David W.; Oppenheim, Irving J.
2003-08-01
Acoustic emission testing is an important technology for evaluating structural materials, and especially for detecting damage in structural members. Significant new capabilities may be gained by developing MEMS transducers for acoustic emission testing, including permanent bonding or embedment for superior coupling, greater density of transducer placement, and a bundle of transducers on each device tuned to different frequencies. Additional advantages include capabilities for maintenance of signal histories and coordination between multiple transducers. We designed a MEMS device for acoustic emission testing that features two different mechanical types, a hexagonal plate design and a spring-mass design, with multiple detectors of each type at ten different frequencies in the range of 100 kHz to 1 MHz. The devices were fabricated in the multi-user polysilicon surface micromachining (MUMPs) process and we have conducted electrical characterization experiments and initial experiments on acoustic emission detection. We first report on C(V) measurements and perform a comparison between predicted (design) and measured response. We next report on admittance measurements conducted at pressures varying from vacuum to atmospheric, identifying the resonant frequencies and again providing a comparison with predicted performance. We then describe initial calibration experiments that compare the performance of the detectors to other acoustic emission transducers, and we discuss the overall performance of the device as a sensor suite, as contrasted to the single-channel performance of most commercial transducers.
A Comparison of Single-Cycle Versus Multiple-Cycle Proof Testing Strategies
NASA Technical Reports Server (NTRS)
McClung, R. C.; Chell, G. G.; Millwater, H. R.; Russell, D. A.; Millwater, H. R.
1999-01-01
Single-cycle and multiple-cycle proof testing (SCPT and MCPT) strategies for reusable aerospace propulsion system components are critically evaluated and compared from a rigorous elastic-plastic fracture mechanics perspective. Earlier MCPT studies are briefly reviewed. New J-integral estimation methods for semielliptical surface cracks and cracks at notches are derived and validated. Engineering methods are developed to characterize crack growth rates during elastic-plastic fatigue crack growth (FCG) and the tear-fatigue interaction near instability. Surface crack growth experiments are conducted with Inconel 718 to characterize tearing resistance, FCG under small-scale yielding and elastic-plastic conditions, and crack growth during simulated MCPT. Fractography and acoustic emission studies provide additional insight. The relative merits of SCPT and MCPT are directly compared using a probabilistic analysis linked with an elastic-plastic crack growth computer code. The conditional probability of failure in service is computed for a population of components that have survived a previous proof test, based on an assumed distribution of initial crack depths. Parameter studies investigate the influence of proof factor, tearing resistance, crack shape, initial crack depth distribution, and notches on the MCPT versus SCPT comparison. The parameter studies provide a rational basis to formulate conclusions about the relative advantages and disadvantages of SCPT and MCPT. Practical engineering guidelines are proposed to help select the optimum proof test protocol in a given application.
A Comparison of Single-Cycle Versus Multiple-Cycle Proof Testing Strategies
NASA Technical Reports Server (NTRS)
McClung, R. C.; Chell, G. G.; Millwater, H. R.; Russell, D. A.; Orient, G. E.
1996-01-01
Single-cycle and multiple-cycle proof testing (SCPT and MCPT) strategies for reusable aerospace propulsion system components are critically evaluated and compared from a rigorous elastic-plastic fracture mechanics perspective. Earlier MCPT studies are briefly reviewed. New J-integral estimation methods for semi-elliptical surface cracks and cracks at notches are derived and validated. Engineering methods are developed to characterize crack growth rates during elastic-plastic fatigue crack growth (FCG) and the tear-fatigue interaction near instability. Surface crack growth experiments are conducted with Inconel 718 to characterize tearing resistance, FCG under small-scale yielding and elastic-plastic conditions, and crack growth during simulated MCPT. Fractography and acoustic emission studies provide additional insight. The relative merits of SCPT and MCPT are directly compared using a probabilistic analysis linked with an elastic-plastic crack growth computer code. The conditional probability of failure in service is computed for a population of components that have survived a previous proof test, based on an assumed distribution of initial crack depths. Parameter studies investigate the influence of proof factor, tearing resistance, crack shape, initial crack depth distribution, and notches on the MCPT vs. SCPT comparison. The parameter studies provide a rational basis to formulate conclusions about the relative advantages and disadvantages of SCPT and MCPT. Practical engineering guidelines are proposed to help select the optimum proof test protocol in a given application.
A novel statistical method for quantitative comparison of multiple ChIP-seq datasets.
Chen, Li; Wang, Chi; Qin, Zhaohui S; Wu, Hao
2015-06-15
ChIP-seq is a powerful technology to measure the protein binding or histone modification strength in the whole genome scale. Although there are a number of methods available for single ChIP-seq data analysis (e.g. 'peak detection'), rigorous statistical method for quantitative comparison of multiple ChIP-seq datasets with the considerations of data from control experiment, signal to noise ratios, biological variations and multiple-factor experimental designs is under-developed. In this work, we develop a statistical method to perform quantitative comparison of multiple ChIP-seq datasets and detect genomic regions showing differential protein binding or histone modification. We first detect peaks from all datasets and then union them to form a single set of candidate regions. The read counts from IP experiment at the candidate regions are assumed to follow Poisson distribution. The underlying Poisson rates are modeled as an experiment-specific function of artifacts and biological signals. We then obtain the estimated biological signals and compare them through the hypothesis testing procedure in a linear model framework. Simulations and real data analyses demonstrate that the proposed method provides more accurate and robust results compared with existing ones. An R software package ChIPComp is freely available at http://web1.sph.emory.edu/users/hwu30/software/ChIPComp.html. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.
Advanced Image Processing for Defect Visualization in Infrared Thermography
NASA Technical Reports Server (NTRS)
Plotnikov, Yuri A.; Winfree, William P.
1997-01-01
Results of a defect visualization process based on pulse infrared thermography are presented. Algorithms have been developed to reduce the amount of operator participation required in the process of interpreting thermographic images. The algorithms determine the defect's depth and size from the temporal and spatial thermal distributions that exist on the surface of the investigated object following thermal excitation. A comparison of the results from thermal contrast, time derivative, and phase analysis methods for defect visualization are presented. These comparisons are based on three dimensional simulations of a test case representing a plate with multiple delaminations. Comparisons are also based on experimental data obtained from a specimen with flat bottom holes and a composite panel with delaminations.
Trick, Lana M; Mutreja, Rachna; Hunt, Kelly
2012-02-01
An individual-differences approach was used to investigate the roles of visuospatial working memory and the executive in multiple-object tracking. The Corsi Blocks and Visual Patterns Tests were used to assess visuospatial working memory. Two relatively nonspatial measures of the executive were used: operation span (OSPAN) and reading span (RSPAN). For purposes of comparison, the digit span test was also included (a measure not expected to correlate with tracking). The tests predicted substantial amounts of variance (R (2) = .33), and the visuospatial measures accounted for the majority (R (2) = .30), with each making a significant contribution. Although the executive measures correlated with each other, the RSPAN did not correlate with tracking. The correlation between OSPAN and tracking was similar in magnitude to that between digit span and tracking (p < .05 for both), and when regression was used to partial out shared variance between the two tests, the remaining variance predicted by the OSPAN was minimal (sr ( 2 ) = .029). When measures of spatial memory were included in the regression, the unique variance predicted by the OSPAN became negligible (sr ( 2 ) = .000004). This suggests that the executive, as measured by tests such as the OSPAN, plays little role in explaining individual differences in multiple-object tracking.
Retina verification system based on biometric graph matching.
Lajevardi, Seyed Mehdi; Arakala, Arathi; Davis, Stephen A; Horadam, Kathy J
2013-09-01
This paper presents an automatic retina verification framework based on the biometric graph matching (BGM) algorithm. The retinal vasculature is extracted using a family of matched filters in the frequency domain and morphological operators. Then, retinal templates are defined as formal spatial graphs derived from the retinal vasculature. The BGM algorithm, a noisy graph matching algorithm, robust to translation, non-linear distortion, and small rotations, is used to compare retinal templates. The BGM algorithm uses graph topology to define three distance measures between a pair of graphs, two of which are new. A support vector machine (SVM) classifier is used to distinguish between genuine and imposter comparisons. Using single as well as multiple graph measures, the classifier achieves complete separation on a training set of images from the VARIA database (60% of the data), equaling the state-of-the-art for retina verification. Because the available data set is small, kernel density estimation (KDE) of the genuine and imposter score distributions of the training set are used to measure performance of the BGM algorithm. In the one dimensional case, the KDE model is validated with the testing set. A 0 EER on testing shows that the KDE model is a good fit for the empirical distribution. For the multiple graph measures, a novel combination of the SVM boundary and the KDE model is used to obtain a fair comparison with the KDE model for the single measure. A clear benefit in using multiple graph measures over a single measure to distinguish genuine and imposter comparisons is demonstrated by a drop in theoretical error of between 60% and more than two orders of magnitude.
Ward, John; Sorrels, Ken; Coats, Jesse; Pourmoghaddam, Amir; Deleon, Carlos; Daigneault, Paige
2014-03-01
The purpose of this study was to pilot test our study procedures and estimate parameters for sample size calculations for a randomized controlled trial to determine if bilateral sacroiliac (SI) joint manipulation affects specific gait parameters in asymptomatic individuals with a leg length inequality (LLI). Twenty-one asymptomatic chiropractic students engaged in a baseline 90-second walking kinematic analysis using infrared Vicon® cameras. Following this, participants underwent a functional LLI test. Upon examination participants were classified as: left short leg, right short leg, or no short leg. Half of the participants in each short leg group were then randomized to receive bilateral corrective SI joint chiropractic manipulative therapy (CMT). All participants then underwent another 90-second gait analysis. Pre- versus post-intervention gait data were then analyzed within treatment groups by an individual who was blinded to participant group status. For the primary analysis, all p-values were corrected for multiple comparisons using the Bonferroni method. Within groups, no differences in measured gait parameters were statistically significant after correcting for multiple comparisons. The protocol of this study was acceptable to all subjects who were invited to participate. No participants refused randomization. Based on the data collected, we estimated that a larger main study would require 34 participants in each comparison group to detect a moderate effect size.
Comparison of Motivational Factors between Japanese and United States High School Students
ERIC Educational Resources Information Center
Kavanaugh, Debbie
2009-01-01
Spanning multiple subjects and age groups, U.S. students rate poorly while Japanese students rate highly when subject to international testing. Japanese children complete twice as much homework as their U.S. counterparts and sometimes attend school on Saturdays. The literature review looks at motivation in both U.S. American and Japanese students…
ERIC Educational Resources Information Center
Rust, Tiana B.; See, Sheree Kwong
2007-01-01
This study assessed professional caregivers of persons with Alzheimer disease (AD) and non-caregivers' knowledge about aging and AD. Participants completed modified versions of the Alzheimer Disease Knowledge Test and the multiple-choice version of the Facts on Aging Quiz #1. Overall, knowledge levels about AD and aging were low. Caregivers were…
Binding of Multiple Features in Memory by High-Functioning Adults with Autism Spectrum Disorder
ERIC Educational Resources Information Center
Bowler, Dermot M.; Gaigg, Sebastian B.; Gardiner, John M.
2014-01-01
Diminished episodic memory and diminished use of semantic information to aid recall by individuals with autism spectrum disorder (ASD) are both thought to result from diminished relational binding of elements of complex stimuli. To test this hypothesis, we asked high-functioning adults with ASD and typical comparison participants to study grids in…
Rainbow trout fry were exposed to arsenic in water only, diet only, or both diet and water in 28-d studies evaluating survival and growth. Diets consisted of Lumbriculus variegatus that were exposed to multiple concentrations of waterborne arsenate for 7d and then fed to test fi...
ERIC Educational Resources Information Center
Richards, James M., Jr.; And Others
The New Youth Initiatives in Apprenticeship Program (YAP) was compared with the Youth Career Development Program (YCD). Data for 1979 and 1980 came from an evaluation of YAP projects by CSR, Incorporated, and an evaluation of the YCD projects by the Educational Testing Service. A multiple regression approach was used to compare student…
Influence of Additive and Multiplicative Structure and Direction of Comparison on the Reversal Error
ERIC Educational Resources Information Center
González-Calero, José Antonio; Arnau, David; Laserna-Belenguer, Belén
2015-01-01
An empirical study has been carried out to evaluate the potential of word order matching and static comparison as explanatory models of reversal error. Data was collected from 214 undergraduate students who translated a set of additive and multiplicative comparisons expressed in Spanish into algebraic language. In these multiplicative comparisons…
Bajaj, Meghna; Poornima, P; Praveen, S; Nagaveni, N B; Roopa, K B; Neena, I E; Bharath, K P
To compare CPP-ACP, Tri-calcium phosphate and Hydroxyapatite on remineralization of artificial caries like lesions on primary enamel. Ten extracted Primary molars coated with nail varnish, leaving a window of 2×4 mm on buccal and lingual surface were immersed in demineralizing solution for 96 hours and sectioned longitudinally to obtain 40 sections (4 sections per tooth) and were randomly divided into 4 groups (A to D) n=10; Group A: negative control, Group B: CPP-ACP, Group C: Tri-calcium phosphate, Group D: Hydroxyapatite. Sections were subjected to pH cycling for 10 days and were evaluated by polarized light microscope before and after treatment. Intra group comparison of demineralization and remineralization was done by paired t-test. One way ANOVA was used for multiple group comparisons followed by post HOC TUKEY'S Test for group wise comparisons. Remineralization was found more with Group D followed by Group B, C and A. Hydroxyapatite showed better remineralization when compared to CPP-ACP and Tri-calcium phosphate.
NASA Technical Reports Server (NTRS)
Sellers, J. P.
1976-01-01
Analysis of the data heat pipe radiator systems tested in both vacuum and ambient environments was continued. The systems included (1) a feasibility VCHP header heat-pipe panel, (2) the same panel reworked to eliminate the VCHP feature and referred to as the feasibility fluid header panel, and (3) an optimized flight-weight fluid header panel termed the 'prototype.' A description of freeze-thaw thermal vacuum tests conducted on the feasibility VCHP was included. In addition, the results of ambient tests made on the feasibility fluid header are presented, including a comparison with analytical results. A thermal model of a fluid header heat pipe radiator was constructed and a computer program written. The program was used to make a comparison of the VCHP and fluid-header concepts for both single and multiple panel applications. The computer program was also employed for a parametric study, including optimum feeder heat pipe spacing, of the prototype fluid header.
ERIC Educational Resources Information Center
Noell, George H.; Gresham, Frank M.
2001-01-01
Describes design logic and potential uses of a variant of the multiple-baseline design. The multiple-baseline multiple-sequence (MBL-MS) consists of multiple-baseline designs that are interlaced with one another and include all possible sequences of treatments. The MBL-MS design appears to be primarily useful for comparison of treatments taking…
Elias, Andrew; Crayton, Samuel H; Warden-Rothman, Robert; Tsourkas, Andrew
2014-07-28
Given the rapidly expanding library of disease biomarkers and targeting agents, the number of unique targeted nanoparticles is growing exponentially. The high variability and expense of animal testing often makes it unfeasible to examine this large number of nanoparticles in vivo. This often leads to the investigation of a single formulation that performed best in vitro. However, nanoparticle performance in vivo depends on many variables, many of which cannot be adequately assessed with cell-based assays. To address this issue, we developed a lanthanide-doped nanoparticle method that allows quantitative comparison of multiple targeted nanoparticles simultaneously. Specifically, superparamagnetic iron oxide (SPIO) nanoparticles with different targeting ligands were created, each with a unique lanthanide dopant. Following the simultaneous injection of the various SPIO compositions into tumor-bearing mice, inductively coupled plasma mass spectroscopy was used to quantitatively and orthogonally assess the concentration of each SPIO composition in serial blood and resected tumor samples.
Evidence-based point-of-care tests and device designs for disaster preparedness.
Brock, T Keith; Mecozzi, Daniel M; Sumner, Stephanie; Kost, Gerald J
2010-01-01
To define pathogen tests and device specifications needed for emerging point-of-care (POC) technologies used in disasters. Surveys included multiple-choice and ranking questions. Multiple-choice questions were analyzed with the chi2 test for goodness-of-fit and the binomial distribution test. Rankings were scored and compared using analysis of variance and Tukey's multiple comparison test. Disaster care experts on the editorial boards of the American Journal of Disaster Medicine and the Disaster Medicine and Public Health Preparedness, and the readers of the POC Journal. Vibrio cholera and Staphylococcus aureus were top-ranked pathogens for testing in disaster settings. Respondents felt that disaster response teams should be equipped with pandemic infectious disease tests for novel 2009 H1N1 and avian H5N1 influenza (disaster care, p < 0.05; POC, p < 0.01). In disaster settings, respondents preferred self-contained test cassettes (disaster care, p < 0.05; POC, p < 0.001) for direct blood sampling (POC, p < 0.01) and disposal of biological waste (disaster care, p < 0.05; POC, p < 0.001). Multiplex testing performed at the POC was preferred in urgent care and emergency room settings. Evidence-based needs assessment identifies pathogen detection priorities in disaster care scenarios, in which Vibrio cholera, methicillin-sensitive and methicillin-resistant Staphylococcus aureus, and Escherichia coli ranked the highest. POC testing should incorporate setting-specific design criteria such as safe disposable cassettes and direct blood sampling at the site of care.
Using Replicates in Information Retrieval Evaluation.
Voorhees, Ellen M; Samarov, Daniel; Soboroff, Ian
2017-09-01
This article explores a method for more accurately estimating the main effect of the system in a typical test-collection-based evaluation of information retrieval systems, thus increasing the sensitivity of system comparisons. Randomly partitioning the test document collection allows for multiple tests of a given system and topic (replicates). Bootstrap ANOVA can use these replicates to extract system-topic interactions-something not possible without replicates-yielding a more precise value for the system effect and a narrower confidence interval around that value. Experiments using multiple TREC collections demonstrate that removing the topic-system interactions substantially reduces the confidence intervals around the system effect as well as increases the number of significant pairwise differences found. Further, the method is robust against small changes in the number of partitions used, against variability in the documents that constitute the partitions, and the measure of effectiveness used to quantify system effectiveness.
Shock Waves Mitigation at Blunt Bodies Using Needles and Shells Against a Supersonic Flow
NASA Technical Reports Server (NTRS)
Gilinsky, M.; Blankson, I. M.; Sakharov, V. I.; Shvets, A. I.
2004-01-01
The paper contains some experimental and numerical simulation test results on cylindrical blunt body drag reduction using thin spikes or shell mounted in front of a body against a supersonic flow. Experimental tests were conducted using the Aeromechanics and Gas Dynamics Laboratory facilities at the Institute of Mechanics of Moscow State University (IMMSU). Numerical simulations utilizing NASA and IM/MSU codes were conducted at the Hampton University Fluid Mechanics and Acoustics Laboratory. The main purpose of this research is to examine the efficiency of application of multiple spikes for drag reduction and flow stability at the front of a blunt body in different flight conditions, i.e. Mach number, angle of attack, etc. The principal conclusions of these test results are: multiple spike/needle application leads to decrease of drag reduction benefits by comparison with the case of one central mounted needle at the front of a blunt body, but increase lift benefits.
Using Replicates in Information Retrieval Evaluation
VOORHEES, ELLEN M.; SAMAROV, DANIEL; SOBOROFF, IAN
2018-01-01
This article explores a method for more accurately estimating the main effect of the system in a typical test-collection-based evaluation of information retrieval systems, thus increasing the sensitivity of system comparisons. Randomly partitioning the test document collection allows for multiple tests of a given system and topic (replicates). Bootstrap ANOVA can use these replicates to extract system-topic interactions—something not possible without replicates—yielding a more precise value for the system effect and a narrower confidence interval around that value. Experiments using multiple TREC collections demonstrate that removing the topic-system interactions substantially reduces the confidence intervals around the system effect as well as increases the number of significant pairwise differences found. Further, the method is robust against small changes in the number of partitions used, against variability in the documents that constitute the partitions, and the measure of effectiveness used to quantify system effectiveness. PMID:29905334
Comparison of Force and Moment Coefficients for the Same Test Article in Multiple Wind Tunnels
NASA Technical Reports Server (NTRS)
Deloach, Richard
2013-01-01
This paper compares the results of force and moment measurements made on the same test article and with the same balance in three transonic wind tunnels. Comparisons are made for the same combination of Reynolds number, Mach number, sideslip angle, control surface configuration, and angle of attack range. Between-tunnel force and moment differences are quantified. An analysis of variance was performed at four unique sites in the design space to assess the statistical significance of between-tunnel variation and any interaction with angle of attack. Tunnel to tunnel differences too large to attribute to random error were detected were observed for all forces and moments. In some cases these differences were independent of angle of attack and in other cases they changed with angle of attack.
The Flow Dimension and Aquifer Heterogeneity: Field evidence and Numerical Analyses
NASA Astrophysics Data System (ADS)
Walker, D. D.; Cello, P. A.; Valocchi, A. J.; Roberts, R. M.; Loftis, B.
2008-12-01
The Generalized Radial Flow approach to hydraulic test interpretation infers the flow dimension to describe the geometry of the flow field during a hydraulic test. Noninteger values of the flow dimension often are inferred for tests in highly heterogeneous aquifers, yet subsequent modeling studies typically ignore the flow dimension. Monte Carlo analyses of detailed numerical models of aquifer tests examine the flow dimension for several stochastic models of heterogeneous transmissivity, T(x). These include multivariate lognormal, fractional Brownian motion, a site percolation network, and discrete linear features with lengths distributed as power-law. The behavior of the simulated flow dimensions are compared to the flow dimensions observed for multiple aquifer tests in a fractured dolomite aquifer in the Great Lakes region of North America. The combination of multiple hydraulic tests, observed fracture patterns, and the Monte Carlo results are used to screen models of heterogeneity and their parameters for subsequent groundwater flow modeling. The comparison shows that discrete linear features with lengths distributed as a power-law appear to be the most consistent with observations of the flow dimension in fractured dolomite aquifers.
NASA Astrophysics Data System (ADS)
Giudici, Mauro; Casabianca, Davide; Comunian, Alessandro
2015-04-01
The basic classical inverse problem of groundwater hydrology aims at determining aquifer transmissivity (T ) from measurements of hydraulic head (h), estimates or measures of source terms and with the least possible knowledge on hydraulic transmissivity. The theory of inverse problems shows that this is an example of ill-posed problem, for which non-uniqueness and instability (or at least ill-conditioning) might preclude the computation of a physically acceptable solution. One of the methods to reduce the problems with non-uniqueness, ill-conditioning and instability is a tomographic approach, i.e., the use of data corresponding to independent flow situations. The latter might correspond to different hydraulic stimulations of the aquifer, i.e., to different pumping schedules and flux rates. Three inverse methods have been analyzed and tested to profit from the use of multiple sets of data: the Differential System Method (DSM), the Comparison Model Method (CMM) and the Double Constraint Method (DCM). DSM and CMM need h all over the domain and thus the first step for their application is the interpolation of measurements of h at sparse points. Moreover, they also need the knowledge of the source terms (aquifer recharge, well pumping rates) all over the aquifer. DSM is intrinsically based on the use of multiple data sets, which permit to write a first-order partial differential equation for T , whereas CMM and DCM were originally proposed to invert a single data set and have been extended to work with multiple data sets in this work. CMM and DCM are based on Darcy's law, which is used to update an initial guess of the T field with formulas based on a comparison of different hydraulic gradients. In particular, the CMM algorithm corrects the T estimate with ratio of the observed hydraulic gradient and that obtained with a comparison model which shares the same boundary conditions and source terms as the model to be calibrated, but a tentative T field. On the other hand the DCM algorithm applies the ratio of the hydraulic gradients obtained for two different forward models, one with the same boundary conditions and source terms as the model to be calibrated and the other one with prescribed head at the positions where in- or out-flow is known and h is measured. For DCM and CMM, multiple stimulation is used by updating the T field separately for each data set and then combining the resulting updated fields with different possible statistics (arithmetic, geometric or harmonic mean, median, least change, etc.). The three algorithms are tested and their characteristics and results are compared with a field data set, which was provided by prof. Fritz Stauffer (ETH) and corresponding to a pumping test in a thin alluvial aquifer in northern Switzerland. Three data sets are available and correspond to the undisturbed state, to the flow field created by a single pumping well and to the situation created by an 'hydraulic dipole', i.e., an extraction and an injection wells. These data sets permit to test the three inverse methods and the different options which can be chosen for their use.
Hu, Xiaofeng; Hu, Rui; Zhang, Zhaowei; Li, Peiwu; Zhang, Qi; Wang, Min
2016-09-01
A sensitive and specific immunoaffinity column to clean up and isolate multiple mycotoxins was developed along with a rapid one-step sample preparation procedure for ultra-performance liquid chromatography-tandem mass spectrometry analysis. Monoclonal antibodies against aflatoxin B1, aflatoxin B2, aflatoxin G1, aflatoxin G2, zearalenone, ochratoxin A, sterigmatocystin, and T-2 toxin were coupled to microbeads for mycotoxin purification. We optimized a homogenization and extraction procedure as well as column loading and elution conditions to maximize recoveries from complex feed matrices. This method allowed rapid, simple, and simultaneous determination of mycotoxins in feeds with a single chromatographic run. Detection limits for these toxins ranged from 0.006 to 0.12 ng mL(-1), and quantitation limits ranged from 0.06 to 0.75 ng mL(-1). Concentration curves were linear from 0.12 to 40 μg kg(-1) with correlation coefficients of R (2) > 0.99. Intra-assay and inter-assay comparisons indicated excellent repeatability and reproducibility of the multiple immunoaffinity columns. As a proof of principle, 80 feed samples were tested and several contained multiple mycotoxins. This method is sensitive, rapid, and durable enough for multiple mycotoxin determinations that fulfill European Union and Chinese testing criteria.
Dellicour, Simon; Lecocq, Thomas
2013-10-01
GCALIGNER 1.0 is a computer program designed to perform a preliminary data comparison matrix of chemical data obtained by GC without MS information. The alignment algorithm is based on the comparison between the retention times of each detected compound in a sample. In this paper, we test the GCALIGNER efficiency on three datasets of the chemical secretions of bumble bees. The algorithm performs the alignment with a low error rate (<3%). GCALIGNER 1.0 is a useful, simple and free program based on an algorithm that enables the alignment of table-type data from GC. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
It pays to compare: an experimental study on computational estimation.
Star, Jon R; Rittle-Johnson, Bethany
2009-04-01
Comparing and contrasting examples is a core cognitive process that supports learning in children and adults across a variety of topics. In this experimental study, we evaluated the benefits of supporting comparison in a classroom context for children learning about computational estimation. Fifth- and sixth-grade students (N=157) learned about estimation either by comparing alternative solution strategies or by reflecting on the strategies one at a time. At posttest and retention test, students who compared were more flexible problem solvers on a variety of measures. Comparison also supported greater conceptual knowledge, but only for students who already knew some estimation strategies. These findings indicate that comparison is an effective learning and instructional practice in a domain with multiple acceptable answers.
Evaluation of water-quality data and monitoring program for Lake Travis, near Austin, Texas
Rast, Walter; Slade, Raymond M.
1998-01-01
The multiple-comparison tests indicate that, for some constituents, a single sampling site for a constituent or property might adequately characterize the water quality of Lake Travis for that constituent or property. However, multiple sampling sites are required to provide information of sufficient temporal and spatial resolution to accurately evaluate other water-quality constituents for the reservoir. For example, the water-quality data from surface samples and from bottom samples indicate that nutrients (nitrogen, phosphorus) might require additional sampling sites for a more accurate characterization of their in-lake dynamics.
Closed-Loop Control for Sonic Fatigue Testing Systems
NASA Technical Reports Server (NTRS)
Rizzi, Stephen A.; Bossaert, Guido
2001-01-01
This article documents recent improvements to the acoustic control system of the Thermal Acoustic Fatigue Apparatus (TAFA), a progressive wave tube test facility at the NASA Langley Research Center, Hampton, VA. A brief summary of past acoustic performance is first given to serve as a basis of comparison with the new performance data using a multiple-input, closed-loop, narrow-band controller. Performance data in the form of test section acoustic power spectral densities and coherence are presented for a variety of input spectra including uniform, band-limited random and an expendable launch vehicle payload bay environment.
NASA Technical Reports Server (NTRS)
Walker, R.; Gupta, N.
1984-01-01
The important algorithm issues necessary to achieve a real time flutter monitoring system; namely, the guidelines for choosing appropriate model forms, reduction of the parameter convergence transient, handling multiple modes, the effect of over parameterization, and estimate accuracy predictions, both online and for experiment design are addressed. An approach for efficiently computing continuous-time flutter parameter Cramer-Rao estimate error bounds were developed. This enables a convincing comparison of theoretical and simulation results, as well as offline studies in preparation for a flight test. Theoretical predictions, simulation and flight test results from the NASA Drones for Aerodynamic and Structural Test (DAST) Program are compared.
Equilibrium Performance Changes Produced by Atropine in M. mulatta and M. fascicularis.
1981-09-01
the behavior of one animal within each group was more severely disrupted than the others. A Student -Newman-Keuls Multiple Comparison Test (31) on the...Med 45(11):1291- 1297 (1974). 7. I)ix, M. R. Treatment of vertigo. Physiotherapy 60(12):380-384 (1974). 8. Fregly, A. R., M. J. Smith, C. D. Wood, and
ERIC Educational Resources Information Center
Poteat, V. Paul; Scheer, Jillian R.; Chong, Eddie S. K.
2016-01-01
There is little data on whether school discipline or juvenile justice sanctions are directed disproportionately toward sexual minority youth (e.g., lesbian, gay, bisexual, or questioning; LGBQ) compared with heterosexual youth and even less on factors that may relate to such disparities. We tested for sexual orientation-based disparities in school…
Cultural Perspectives on Aging and Well-Being: A Comparison of Japan and the United States
ERIC Educational Resources Information Center
Karasawa, Mayumi; Curhan, Katherine B.; Markus, Hazel Rose; Kitayama, Shinobu S.; Love, Gayle Dienberg; Radler, Barry T.; Ryff, Carol D.
2011-01-01
This study investigated age differences in multiple aspects of psychological well-being among midlife and older adults in Japan (N = 482) and the United States (N = 3,032) to test the hypothesis that older Japanese adults would rate aspects of their well-being (personal growth, purpose in life, positive relations with others) more highly that…
Casanova, I; Diaz, A; Pinto, S; de Carvalho, M
2014-04-01
The technique of threshold tracking to test axonal excitability gives information about nodal and internodal ion channel function. We aimed to investigate variability of the motor excitability measurements in healthy controls, taking into account age, gender, body mass index (BMI) and small changes in skin temperature. We examined the left median nerve of 47 healthy controls using the automated threshold-tacking program, QTRAC. Statistical multiple regression analysis was applied to test relationship between nerve excitability measurements and subject variables. Comparisons between genders did not find any significant difference (P>0.2 for all comparisons). Multiple regression analysis showed that motor amplitude decreases with age and temperature, stimulus-response slope decreases with age and BMI, and that accommodation half-time decrease with age and temperature. The changes related to demographic features on TRONDE protocol parameters are small and less important than in conventional nerve conduction studies. Nonetheless, our results underscore the relevance of careful temperature control, and indicate that interpretation of stimulus-response slope and accommodation half-time should take into account age and BMI. In contrast, gender is not of major relevance to axonal threshold findings in motor nerves. Copyright © 2014 Elsevier Masson SAS. All rights reserved.
Detection of burst suppression patterns in EEG using recurrence rate.
Liang, Zhenhu; Wang, Yinghua; Ren, Yongshao; Li, Duan; Voss, Logan; Sleigh, Jamie; Li, Xiaoli
2014-01-01
Burst suppression is a unique electroencephalogram (EEG) pattern commonly seen in cases of severely reduced brain activity such as overdose of general anesthesia. It is important to detect burst suppression reliably during the administration of anesthetic or sedative agents, especially for cerebral-protective treatments in various neurosurgical diseases. This study investigates recurrent plot (RP) analysis for the detection of the burst suppression pattern (BSP) in EEG. The RP analysis is applied to EEG data containing BSPs collected from 14 patients. Firstly we obtain the best selection of parameters for RP analysis. Then, the recurrence rate (RR), determinism (DET), and entropy (ENTR) are calculated. Then RR was selected as the best BSP index one-way analysis of variance (ANOVA) and multiple comparison tests. Finally, the performance of RR analysis is compared with spectral analysis, bispectral analysis, approximate entropy, and the nonlinear energy operator (NLEO). ANOVA and multiple comparison tests showed that the RR could detect BSP and that it was superior to other measures with the highest sensitivity of suppression detection (96.49%, P = 0.03). Tracking BSP patterns is essential for clinical monitoring in critically ill and anesthetized patients. The purposed RR may provide an effective burst suppression detector for developing new patient monitoring systems.
The role of perceived discrimination on active aging.
Fernandez-Ballesteros, Rocio; Olmos, Ricardo; Santacreu, Marta; Bustillos, Antonio; Molina, Maria Angeles
2017-07-01
Among older adults, perceived age discrimination is highly associated with unhealthy outcomes and dissatisfaction. Active aging is a multidimensional concept described by a set of characteristics, particularly health, positive mood and control; most importantly, active aging is currently at the core of public policies. The aim of the present study was to test to what extent perceived discrimination influences active aging. Methods A total of 2005 older adults in three representative samples from regions of Germany, Mexico and Spain participated; they were tested on active aging and perceived discrimination. First, active aging was defined as high reported health, life satisfaction and self-perception of aging. Second, authors introduced the assumption that, in the total sample, structural equation modelling would confirm the hypothesis of a direct negative link between perceived age discrimination and active aging. Finally, multiple group comparison performed through structural equation modelling also provided support for the negative association between perceived discrimination and active aging proposed. In spite of the differences found among the three countries in both active aging variables and age discrimination perception, multiple group comparison indicates that regardless of the culture, perceived discrimination is a negative predictor of active aging. Copyright © 2017 Elsevier B.V. All rights reserved.
Effect of Air Pollution on Exacerbations of Bronchiectasis in Badalona, Spain, 2008-2016.
Garcia-Olivé, Ignasi; Stojanovic, Zoran; Radua, Joaquim; Rodriguez-Pons, Laura; Martinez-Rivera, Carlos; Ruiz Manzano, Juan
2018-05-17
Air pollution has been widely associated with respiratory diseases. Nevertheless, the association between air pollution and exacerbations of bronchiectasis has been less studied. To analyze the effect of air pollution on exacerbations of bronchiectasis. This was a retrospective observational study conducted in Badalona. The number of daily hospital admissions and emergency room visits related to exacerbation of bronchiectasis (ICD-9 code 494.1) between 2008 and 2016 was obtained. We used simple Poisson regressions to test the effects of daily mean temperature, SO2, NO2, CO, and PM10 levels on bronchiectasis-related emergencies and hospitalizations on the same day and 1-4 days after. All p values were corrected for multiple comparisons. SO2 was significantly associated with an increase in the number of hospitalizations (lags 0, 1, 2, and 3). None of these associations remained significant after correcting for multiple comparisons. The number of emergency room visits was associated with higher levels of SO2 (lags 0-4). After correcting for multiple comparisons, the association between emergency room visits and SO2 levels was statistically significant for lag 0 (p = 0.043), lag 1 (p = 0.018), and lag 3 (p = 0.050). The number of emergency room visits for exacerbation of bronchiectasis is associated with higher levels of SO2. © 2018 S. Karger AG, Basel.
Building Diversified Multiple Trees for classification in high dimensional noisy biomedical data.
Li, Jiuyong; Liu, Lin; Liu, Jixue; Green, Ryan
2017-12-01
It is common that a trained classification model is applied to the operating data that is deviated from the training data because of noise. This paper will test an ensemble method, Diversified Multiple Tree (DMT), on its capability for classifying instances in a new laboratory using the classifier built on the instances of another laboratory. DMT is tested on three real world biomedical data sets from different laboratories in comparison with four benchmark ensemble methods, AdaBoost, Bagging, Random Forests, and Random Trees. Experiments have also been conducted on studying the limitation of DMT and its possible variations. Experimental results show that DMT is significantly more accurate than other benchmark ensemble classifiers on classifying new instances of a different laboratory from the laboratory where instances are used to build the classifier. This paper demonstrates that an ensemble classifier, DMT, is more robust in classifying noisy data than other widely used ensemble methods. DMT works on the data set that supports multiple simple trees.
Zhao, Ni; Chen, Jun; Carroll, Ian M.; Ringel-Kulka, Tamar; Epstein, Michael P.; Zhou, Hua; Zhou, Jin J.; Ringel, Yehuda; Li, Hongzhe; Wu, Michael C.
2015-01-01
High-throughput sequencing technology has enabled population-based studies of the role of the human microbiome in disease etiology and exposure response. Distance-based analysis is a popular strategy for evaluating the overall association between microbiome diversity and outcome, wherein the phylogenetic distance between individuals’ microbiome profiles is computed and tested for association via permutation. Despite their practical popularity, distance-based approaches suffer from important challenges, especially in selecting the best distance and extending the methods to alternative outcomes, such as survival outcomes. We propose the microbiome regression-based kernel association test (MiRKAT), which directly regresses the outcome on the microbiome profiles via the semi-parametric kernel machine regression framework. MiRKAT allows for easy covariate adjustment and extension to alternative outcomes while non-parametrically modeling the microbiome through a kernel that incorporates phylogenetic distance. It uses a variance-component score statistic to test for the association with analytical p value calculation. The model also allows simultaneous examination of multiple distances, alleviating the problem of choosing the best distance. Our simulations demonstrated that MiRKAT provides correctly controlled type I error and adequate power in detecting overall association. “Optimal” MiRKAT, which considers multiple candidate distances, is robust in that it suffers from little power loss in comparison to when the best distance is used and can achieve tremendous power gain in comparison to when a poor distance is chosen. Finally, we applied MiRKAT to real microbiome datasets to show that microbial communities are associated with smoking and with fecal protease levels after confounders are controlled for. PMID:25957468
Antanasijević, Davor; Pocajt, Viktor; Povrenović, Dragan; Perić-Grujić, Aleksandra; Ristić, Mirjana
2013-12-01
The aims of this study are to create an artificial neural network (ANN) model using non-specific water quality parameters and to examine the accuracy of three different ANN architectures: General Regression Neural Network (GRNN), Backpropagation Neural Network (BPNN) and Recurrent Neural Network (RNN), for prediction of dissolved oxygen (DO) concentration in the Danube River. The neural network model has been developed using measured data collected from the Bezdan monitoring station on the Danube River. The input variables used for the ANN model are water flow, temperature, pH and electrical conductivity. The model was trained and validated using available data from 2004 to 2008 and tested using the data from 2009. The order of performance for the created architectures based on their comparison with the test data is RNN > GRNN > BPNN. The ANN results are compared with multiple linear regression (MLR) model using multiple statistical indicators. The comparison of the RNN model with the MLR model indicates that the RNN model performs much better, since all predictions of the RNN model for the test data were within the error of less than ± 10 %. In case of the MLR, only 55 % of predictions were within the error of less than ± 10 %. The developed RNN model can be used as a tool for the prediction of DO in river waters.
Robaski, Aliden-Willian; Pamato, Saulo; Tomás-de Oliveira, Marcelo; Pereira, Jefferson-Ricardo
2017-07-01
The enamel condition and the quality of surface are points that need to be considered for achieving optimal efficiency in the treatment with orthodontic brackets. The aim of this study was to assess the immediate bond strength of metallic brackets cemented to dental. Forty human premolars were double-sectioned, placed in PVC matrices and randomly divided into 10 groups (n=8). They received artificial saliva contamination before or after the application of adhesive systems, except for the control groups. The metallic brackets were cemented using two orthodontic cements (Transbond™ Plus Color Change, 3M Unitek e Transbond™ XT Light, 3M Unitek). The specimens were subjected to mechanical shear bond strength testing and classified according to the fracture pattern. The results were analyzed using a two-way ANOVA and Tukey's test for multiple comparisons ( p <0.05). ANOVA analysis showed statistically significant differences between the groups ( p =0.01). The Tukey's multiple comparison test indicated statistically significant difference between G6 and G7 groups ( p <0.05). A high prevalence of adhesive failure in the groups receiving the hydrophobic adhesive system. The saliva contamination prior to the application of a hydrophobic simplified conventional adhesive system was responsible for decreasing the immediate bond strength values of brackets cemented on the dental enamel. Key words: Bonding, orthodontic brackets, shear bond strength, saliva, adhesive systems.
Hong, Hye Jeong; Kim, Jin Sung; Seo, Wan Seok; Koo, Bon Hoon; Bai, Dai Seg; Jeong, Jin Young
2010-01-01
Objective We investigated executive functions (EFs), as evaluated by the Wisconsin Card Sorting Test (WCST), and other EF between lower grades (LG) and higher grades (HG) in elementary-school-age attention deficit hyperactivity disorder (ADHD) children. Methods We classified a sample of 112 ADHD children into 4 groups (composed of 28 each) based on age (LG vs. HG) and WCST performance [lower vs. higher performance on WCST, defined by the number of completed categories (CC)] Participants in each group were matched according to age, gender, ADHD subtype, and intelligence. We used the Wechsler intelligence Scale for Children 3rd edition to test intelligence and the Computerized Neurocognitive Function Test-IV, which included the WCST, to test EF. Results Comparisons of EFs scores in LG ADHD children showed statistically significant differences in performing digit spans backward, some verbal learning scores, including all memory scores, and Stroop test scores. However, comparisons of EF scores in HG ADHD children did not show any statistically significant differences. Correlation analyses of the CC and EF variables and stepwise multiple regression analysis in LG ADHD children showed a combination of the backward form of the Digit span test and Visual span test in lower-performance ADHD participants significantly predicted the number of CC (R2=0.273, p<0.001). Conclusion This study suggests that the design of any battery of neuropsychological tests for measuring EF in ADHD children should first consider age before interpreting developmental variations and neuropsychological test results. Researchers should consider the dynamics of relationships within EF, as measured by neuropsychological tests. PMID:20927306
Fletcher, Jack M.; Stuebing, Karla K.; Barth, Amy E.; Miciak, Jeremy; Francis, David J.; Denton, Carolyn A.
2013-01-01
Purpose Agreement across methods for identifying students as inadequate responders or as learning disabled is often poor. We report (1) an empirical examination of final status (post-intervention benchmarks) and dual-discrepancy growth methods based on growth during the intervention and final status for assessing response to intervention; and (2) a statistical simulation of psychometric issues that may explain low agreement. Methods After a Tier 2 intervention, final status benchmark criteria were used to identify 104 inadequate and 85 adequate responders to intervention, with comparisons of agreement and coverage for these methods and a dual-discrepancy method. Factors affecting agreement were investigated using computer simulation to manipulate reliability, the intercorrelation between measures, cut points, normative samples, and sample size. Results Identification of inadequate responders based on individual measures showed that single measures tended not to identify many members of the pool of 104 inadequate responders. Poor to fair levels of agreement for identifying inadequate responders were apparent between pairs of measures In the simulation, comparisons across two simulated measures generated indices of agreement (kappa) that were generally low because of multiple psychometric issues inherent in any test. Conclusions Expecting excellent agreement between two correlated tests with even small amounts of unreliability may not be realistic. Assessing outcomes based on multiple measures, such as level of CBM performance and short norm-referenced assessments of fluency may improve the reliability of diagnostic decisions. PMID:25364090
Amato, Russell J.; Hulin, Mary W.; Winsauer, Peter J.
2012-01-01
Dehydroepiandrosterone (DHEA), 7-keto DHEA, and several comparison drugs (ethanol, chlordiazepoxide, rauwolscine, and RO15-4513) were administered to male rats responding under a multiple schedule of food and ethanol presentation to determine their selectively for decreasing ethanol-maintained responding. DHEA and 7-keto DHEA significantly decreased both ethanol- and food-maintained responding, compared to control, while also decreasing blood ethanol concentration (BEC). Acute ethanol administration also decreased responding for both food and ethanol; however, ethanol-maintained responding was more potently decreased than food-maintained responding. BEC remained relatively stable after increasing ethanol doses. Among the other drugs tested, RO15-4513 was the most selective for decreasing ethanol-maintained responding compared to food-maintained responding, and it decreased BECs as ethanol-maintained responding decreased. The largest dose of rauwolscine significantly decreased responding for food, while not affecting ethanol-maintained responding compared to control. Low to intermediate doses of rauwolscine produced small, non-significant increases in ethanol-maintained responding and BECs. Chlordiazepoxide produced significant decreases in food-maintained responding and the dose of ethanol presented, but only at the highest dose tested. Although DHEA and 7-keto DHEA did not decrease ethanol-maintained responding as selectively as ethanol or RO15-4513 under the multiple schedule, these neurosteroids may be valuable pharmacological tools in the development of new treatments for alcohol abuse and dependence. PMID:22473025
Tavazzi, Eleonora; Laganà, Maria Marcella; Bergsland, Niels; Tortorella, Paola; Pinardi, Giovanna; Lunetta, Christian; Corbo, Massimo; Rovaris, Marco
2015-03-01
Primary progressive multiple sclerosis (PPMS) and amyotrophic lateral sclerosis (ALS) seem to share some clinical and pathological features. MRI studies revealed the presence of grey matter (GM) atrophy in both diseases, but no comparative data are available. The objective was to compare the regional patterns of GM tissue loss in PPMS and ALS with voxel-based morphometry (VBM). Eighteen PPMS patients, 20 ALS patients, and 31 healthy controls (HC) were studied with a 1.5 Tesla scanner. VBM was performed to assess volumetric GM differences with age and sex as covariates. Threshold-free cluster enhancement analysis was used to obtain significant clusters. Group comparisons were tested with family-wise error correction for multiple comparisons (p < 0.05) except for HC versus MND which was tested at a level of p < 0.001 uncorrected and a cluster threshold of 20 contiguous voxels. Compared to HC, ALS patients showed GM tissue reduction in selected frontal and temporal areas, while PPMS patients showed a widespread bilateral GM volume decrease, involving both deep and cortical regions. Compared to ALS, PPMS patients showed tissue volume reductions in both deep and cortical GM areas. This preliminary study confirms that PPMS is characterized by a more diffuse cortical and subcortical GM atrophy than ALS and that, in the latter condition, brain damage is present outside the motor system. These results suggest that PPMS and ALS may share pathological features leading to GM tissue loss.
NASA Astrophysics Data System (ADS)
Preston, Daniel; Hill, Larry; Johnson, Carl
2015-06-01
In this paper we describe a novel shock sensitivity test, the Gap Stick Test, which is a generalized variant of the ubiquitous Gap Test. Despite the popularity of the Gap Test, it has some disadvantages: multiple tests must be fired to obtain a single metric, and many tests must be fired to obtain its value to high precision and confidence. Our solution is a test wherein multiple gap tests are joined in series to form a rate stick. The complex re-initiation character of the traditional gap test is thereby retained, but the propagation speed is steady when measured at periodic intervals, and initiation delay in individual segments acts to decrement the average speed. We measure the shock arrival time before and after each inert gap, and compute the average detonation speed through the HE alone (discounting the gap thicknesses). We perform tests for a range of gap thicknesses. We then plot the aforementioned propagation speed as a function of gap thickness. The resulting curve has the same basic structure as a Diameter Effect (DE) curve, and (like the DE curve) terminates at a failure point. Comparison between experiment and hydrocode calculations using ALE3D and the Ignition and Growth reactive burn model calibrated for short duration shock inputs in PBX 9501 is discussed.
Landgren, Ola; Shim, Youn K; Michalek, Joel; Costello, Rene; Burton, Debra; Ketchum, Norma; Calvo, Katherine R; Caporaso, Neil; Raveche, Elizabeth; Middleton, Dan; Marti, Gerald; Vogt, Robert F
2015-11-01
Multiple myeloma has been classified as exhibiting "limited or suggestive evidence" of an association with exposure to herbicides in Vietnam War veterans. Occupational studies have shown that other pesticides (ie, insecticides, herbicides, fungicides) are associated with excess risk of multiple myeloma and its precursor state, monoclonal gammopathy of undetermined significance (MGUS); however, to our knowledge, no studies have uncovered such an association in Vietnam War veterans. To examine the relationship between MGUS and exposure to Agent Orange, including its contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), in Vietnam War veterans. This was a prospective cohort study conducted in 2013 to 2014, testing for MGUS in serum specimens collected and stored in 2002 by the Air Force Health Study (AFHS). The relevant exposure data collected by the AFHS was also used. We tested all specimens in 2013 without knowledge of the exposure status. The AFHS included former US Air Force personnel who participated in Operation Ranch Hand (Ranch Hand veterans) and other US Air Force personnel who had similar duties in Southeast Asia during the same time period (1962 to 1971) but were not involved in herbicide spray missions (comparison veterans). Agent Orange was used by the US Air Force personnel who conducted aerial spray missions of herbicides (Operation Ranch Hand) in Vietnam from 1962 to 1971. We included 479 Ranch Hand veterans and 479 comparison veterans who participated in the 2002 follow-up examination of AFHS. Agent Orange and TCDD. Serum TCDD levels were measured in 1987, 1992, 1997, and 2002. Risk of MGUS measured by prevalence, odds ratios (ORs), and 95% CIs. The 479 Ranch Hand veterans and 479 comparison veterans had similar demographic and lifestyle characteristics and medical histories. The crude prevalence of overall MGUS was 7.1% (34 of 479) in Ranch Hand veterans and 3.1% (15 of 479) in comparison veterans. This translated into a 2.4-fold increased risk for MGUS in Ranch Hand veterans than comparison veterans after adjusting for age, race, BMI in 2002, and the change in BMI between 2002 and the time of blood draw for TCDD measurement (adjusted OR, 2.37; 95% CI, 1.27-4.44; P=.007). Operation Ranch Hand veterans have a significantly increased risk of MGUS, supporting an association between Agent Orange exposure and multiple myeloma.
Characterization and Dynamic Analysis of Long-Cavity Multi-Section Gain- Levered Quantum-Dot Lasers
2013-03-01
test setup .................................................................... 8 Figure 5: Comparison of a Fabry – Perot and distributed feedback...for example Fabry – Perot and distributed-feedback designs), with each possessing advantages and disadvantages that will be discussed in detail in...contrast to Fabry – Perot cavities (two discrete mirrors) that result in lasing over multiple longitudinal modes supported by the cavity. Figure 5 shows
ERIC Educational Resources Information Center
Jacobson, Joseph L.; Jacobson, Sandra W.
2004-01-01
In this paper, we respond to the criticisms and concerns raised by D.V. Cicchetti, A.S. Kaufman, & S.S. Sparrow (this issue) in their review of the PCB literature, with particular attention to our own research in Michigan. We agree that multiple comparisons and functional significance are issues that would benefit from more discussion.…
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ovacik, Meric A.; Androulakis, Ioannis P., E-mail: yannis@rci.rutgers.edu; Biomedical Engineering Department, Rutgers University, Piscataway, NJ 08854
2013-09-15
Pathway-based information has become an important source of information for both establishing evolutionary relationships and understanding the mode of action of a chemical or pharmaceutical among species. Cross-species comparison of pathways can address two broad questions: comparison in order to inform evolutionary relationships and to extrapolate species differences used in a number of different applications including drug and toxicity testing. Cross-species comparison of metabolic pathways is complex as there are multiple features of a pathway that can be modeled and compared. Among the various methods that have been proposed, reaction alignment has emerged as the most successful at predicting phylogeneticmore » relationships based on NCBI taxonomy. We propose an improvement of the reaction alignment method by accounting for sequence similarity in addition to reaction alignment method. Using nine species, including human and some model organisms and test species, we evaluate the standard and improved comparison methods by analyzing glycolysis and citrate cycle pathways conservation. In addition, we demonstrate how organism comparison can be conducted by accounting for the cumulative information retrieved from nine pathways in central metabolism as well as a more complete study involving 36 pathways common in all nine species. Our results indicate that reaction alignment with enzyme sequence similarity results in a more accurate representation of pathway specific cross-species similarities and differences based on NCBI taxonomy.« less
A comparison of single-cycle versus multiple-cycle proof testing strategies
NASA Technical Reports Server (NTRS)
Hudak, S. J., Jr.; Mcclung, R. C.; Bartlett, M. L.; Fitzgerald, J. H.; Russell, D. A.
1990-01-01
An evaluation of single-cycle and multiple-cycle proof testing (MCPT) strategies for SSME components is described. Data for initial sizes and shapes of actual SSME hardware defects are analyzed statistically. Closed-form estimates of the J-integral for surface flaws are derived with a modified reference stress method. The results of load- and displacement-controlled stable crack growth tests on thin IN-718 plates with deep surface flaws are summarized. A J-resistance curve for the surface-cracked configuration is developed and compared with data from thick compact tension specimens. The potential for further crack growth during large unload/reload cycles is discussed, highlighting conflicting data in the literature. A simple model for ductile crack growth during MCPT based on the J-resistance curve is used to study the potential effects of key variables. The projected changes in the crack size distribution during MCPT depend on the interactions between several key parameters, including the number of proof cycles, the nature of the resistance curve, the initial crack size distribution, the component boundary conditions (load vs. displacement control), and the magnitude of the applied load or displacement. The relative advantages of single-cycle and multiple-cycle proof testing appear to be specific, therefore, to individual component geometry, material, and loading.
Is the hibiscus harlequin bug aposematic? The importance of testing multiple predators
Fabricant, Scott A; Smith, Carolynn L
2014-01-01
Aposematism involves predators learning conspicuous signals of defended prey. However, prey species utilize a wide range of chemical (or physical) defenses, which are not likely to be equally aversive to all predators. Aposematism may therefore only be effective against a physiologically sensitive subset of potential predators, and this can only be identified through behavioral testing. We studied the emerging model organism Tectocoris diophthalmus (Heteroptera: Scutelleridae), an aposematically colored but weakly defended shieldback stinkbug, to test the efficacy of its defenses against a suite of predator types. We predicted the bugs' defenses would be ineffectual against both experienced and naïve birds but aversive to predaceous insects. Surprisingly, the opposite pattern was found. Both habituated wild passerines and naïve chickens avoided the bugs, the chickens after only one or two encounters. To avian predators, T. diophthalmus is aposematic. However, praying mantids showed no repellency, aversion, or toxicity associated with adult or juvenile bugs after multiple trials. Comparison with prior studies on mantids using bugs with chemically similar but more concentrated defenses underscores the importance of dose in addition to chemical identity in the efficacy of chemical defenses. Our results also emphasize the importance of behavioral testing with multiple ecologically relevant predators to understand selective pressures shaping aposematic signals and chemical defenses. PMID:24558567
Khavari, Rose; Karmonik, Christof; Shy, Michael; Fletcher, Sophie; Boone, Timothy
2017-02-01
Neurogenic lower urinary tract dysfunction, which is common in patients with multiple sclerosis, has a significant impact on quality of life. In this study we sought to determine brain activity processes during the micturition cycle in female patients with multiple sclerosis and neurogenic lower urinary tract dysfunction. We report brain activity on functional magnetic resonance imaging and simultaneous urodynamic testing in 23 ambulatory female patients with multiple sclerosis. Individual functional magnetic resonance imaging activation maps at strong desire to void and at initiation of voiding were calculated and averaged at Montreal Neuroimaging Institute. Areas of significant activation were identified in these average maps. Subgroup analysis was performed in patients with elicitable neurogenic detrusor overactivity or detrusor-sphincter dyssynergia. Group analysis of all patients at strong desire to void yielded areas of activation in regions associated with executive function (frontal gyrus), emotional regulation (cingulate gyrus) and motor control (putamen, cerebellum and precuneus). Comparison of the average change in activation between previously reported healthy controls and patients with multiple sclerosis showed predominantly stronger, more focal activation in the former and lower, more diffused activation in the latter. Patients with multiple sclerosis who had demonstrable neurogenic detrusor overactivity and detrusor-sphincter dyssynergia showed a trend toward distinct brain activation at full urge and at initiation of voiding respectively. We successfully studied brain activation during the entire micturition cycle in female patients with neurogenic lower urinary tract dysfunction and multiple sclerosis using a concurrent functional magnetic resonance imaging/urodynamic testing platform. Understanding the central neural processes involved in specific parts of micturition in patients with neurogenic lower urinary tract dysfunction may identify areas of interest for future intervention. Copyright © 2017 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.
Random number generators tested on quantum Monte Carlo simulations.
Hongo, Kenta; Maezono, Ryo; Miura, Kenichi
2010-08-01
We have tested and compared several (pseudo) random number generators (RNGs) applied to a practical application, ground state energy calculations of molecules using variational and diffusion Monte Carlo metheds. A new multiple recursive generator with 8th-order recursion (MRG8) and the Mersenne twister generator (MT19937) are tested and compared with the RANLUX generator with five luxury levels (RANLUX-[0-4]). Both MRG8 and MT19937 are proven to give the same total energy as that evaluated with RANLUX-4 (highest luxury level) within the statistical error bars with less computational cost to generate the sequence. We also tested the notorious implementation of linear congruential generator (LCG), RANDU, for comparison. (c) 2010 Wiley Periodicals, Inc.
Benchmarking and performance analysis of the CM-2. [SIMD computer
NASA Technical Reports Server (NTRS)
Myers, David W.; Adams, George B., II
1988-01-01
A suite of benchmarking routines testing communication, basic arithmetic operations, and selected kernel algorithms written in LISP and PARIS was developed for the CM-2. Experiment runs are automated via a software framework that sequences individual tests, allowing for unattended overnight operation. Multiple measurements are made and treated statistically to generate well-characterized results from the noisy values given by cm:time. The results obtained provide a comparison with similar, but less extensive, testing done on a CM-1. Tests were chosen to aid the algorithmist in constructing fast, efficient, and correct code on the CM-2, as well as gain insight into what performance criteria are needed when evaluating parallel processing machines.
Amen, Daniel G; Hanks, Chris; Prunella, Jill R; Green, Aisa
2007-01-01
The authors explored differences in regional cerebral blood flow in 11 impulsive murderers and 11 healthy comparison subjects using single photon emission computed tomography. The authors assessed subjects at rest and during a computerized go/no-go concentration task. Using statistical parametric mapping software, the authors performed voxel-by-voxel t tests to assess significant differences, making family-wide error corrections for multiple comparisons. Murderers were found to have significantly lower relative rCBF during concentration, particularly in areas associated with concentration and impulse control. These results indicate that nonemotionally laden stimuli may result in frontotemporal dysregulation in people predisposed to impulsive violence.
Alonso, Joan Francesc; Romero, Sergio; Mañanas, Miguel Ángel; Rojas, Mónica; Riba, Jordi; Barbanoj, Manel José
2015-10-01
The identification of the brain regions involved in the neuropharmacological action is a potential procedure for drug development. These regions are commonly determined by the voxels showing significant statistical differences after comparing placebo-induced effects with drug-elicited effects. LORETA is an electroencephalography (EEG) source imaging technique frequently used to identify brain structures affected by the drug. The aim of the present study was to evaluate different methods for the correction of multiple comparisons in the LORETA maps. These methods which have been commonly used in neuroimaging and also simulated studies have been applied on a real case of pharmaco-EEG study where the effects of increasing benzodiazepine doses on the central nervous system measured by LORETA were investigated. Data consisted of EEG recordings obtained from nine volunteers who received single oral doses of alprazolam 0.25, 0.5, and 1 mg, and placebo in a randomized crossover double-blind design. The identification of active regions was highly dependent on the selected multiple test correction procedure. The combined criteria approach known as cluster mass was useful to reveal that increasing drug doses led to higher intensity and spread of the pharmacologically induced changes in intracerebral current density.
Space Launch System Scale Model Acoustic Test Ignition Overpressure Testing
NASA Technical Reports Server (NTRS)
Nance, Donald K.; Liever, Peter A.
2015-01-01
The overpressure phenomenon is a transient fluid dynamic event occurring during rocket propulsion system ignition. This phenomenon results from fluid compression of the accelerating plume gas, subsequent rarefaction, and subsequent propagation from the exhaust trench and duct holes. The high-amplitude unsteady fluid-dynamic perturbations can adversely affect the vehicle and surrounding structure. Commonly known as ignition overpressure (IOP), this is an important design-to environment for the Space Launch System (SLS) that NASA is currently developing. Subscale testing is useful in validating and verifying the IOP environment. This was one of the objectives of the Scale Model Acoustic Test (SMAT), conducted at Marshall Space Flight Center (MSFC). The test data quantifies the effectiveness of the SLS IOP suppression system and improves the analytical models used to predict the SLS IOP environments. The reduction and analysis of the data gathered during the SMAT IOP test series requires identification and characterization of multiple dynamic events and scaling of the event waveforms to provide the most accurate comparisons to determine the effectiveness of the IOP suppression systems. The identification and characterization of the overpressure events, the waveform scaling, the computation of the IOP suppression system knockdown factors, and preliminary comparisons to the analytical models are discussed.
Space Launch System Scale Model Acoustic Test Ignition Overpressure Testing
NASA Technical Reports Server (NTRS)
Nance, Donald; Liever, Peter; Nielsen, Tanner
2015-01-01
The overpressure phenomenon is a transient fluid dynamic event occurring during rocket propulsion system ignition. This phenomenon results from fluid compression of the accelerating plume gas, subsequent rarefaction, and subsequent propagation from the exhaust trench and duct holes. The high-amplitude unsteady fluid-dynamic perturbations can adversely affect the vehicle and surrounding structure. Commonly known as ignition overpressure (IOP), this is an important design-to environment for the Space Launch System (SLS) that NASA is currently developing. Subscale testing is useful in validating and verifying the IOP environment. This was one of the objectives of the Scale Model Acoustic Test, conducted at Marshall Space Flight Center. The test data quantifies the effectiveness of the SLS IOP suppression system and improves the analytical models used to predict the SLS IOP environments. The reduction and analysis of the data gathered during the SMAT IOP test series requires identification and characterization of multiple dynamic events and scaling of the event waveforms to provide the most accurate comparisons to determine the effectiveness of the IOP suppression systems. The identification and characterization of the overpressure events, the waveform scaling, the computation of the IOP suppression system knockdown factors, and preliminary comparisons to the analytical models are discussed.
Janssen, T J; Guelen, P J; Vree, T B; Botterblom, M H; Valducci, R
1988-01-01
The bioavailability of a new ambroxol sustained release preparation (75 mg) based on a dialyzing membrane for controlled release was studied in healthy volunteers after single and multiple oral dose in comparison with a standard sustained release formulation in a cross-over study under carefully controlled conditions. Plasma concentrations of ambroxol were measured by means of a HPLC method. Based on AUC data both preparations are found to be bioequivalent, but show different plasma concentration profiles. The test preparation showed a more pronounced sustained release profile than the reference preparation (single dose) resulting in significantly higher steady state plasma levels.
Statistical power analyses using G*Power 3.1: tests for correlation and regression analyses.
Faul, Franz; Erdfelder, Edgar; Buchner, Axel; Lang, Albert-Georg
2009-11-01
G*Power is a free power analysis program for a variety of statistical tests. We present extensions and improvements of the version introduced by Faul, Erdfelder, Lang, and Buchner (2007) in the domain of correlation and regression analyses. In the new version, we have added procedures to analyze the power of tests based on (1) single-sample tetrachoric correlations, (2) comparisons of dependent correlations, (3) bivariate linear regression, (4) multiple linear regression based on the random predictor model, (5) logistic regression, and (6) Poisson regression. We describe these new features and provide a brief introduction to their scope and handling.
Male gender and smoking are related to single, but not to multiple, human aortic aneurysms.
Gutierrez, Paulo S; Leite, Thiago N P; Mangione, Fernanda M
2015-01-01
There is scanty information concerning multiple aortic aneurysms. Thus, we verified if clinical or pathological characteristics are different in patients with multiple (two or more) aortic aneurysms in comparison with those with only one. We selected at the necropsy files of the Heart Institute, São Paulo University School of Medicine, the last 100 cases with aortic aneurysms, comparing between the two groups: sex, age, presence of systemic arterial hypertension, diabetes, dyslipedemia, history of smoking habit, cause of the aneurysm, cause of death, and if the diagnosis was reached during life. Age was analysed by Mann-Whitney test, and the other variables by chi-square or Fisher's exact test. Multiple aneurysms corresponded to 14% of cases. The proportion of women among patients with multiple aneurysms was higher than among those with single aneurysm (64.3% versus 20.9%, P<.01), even if only cases with atherosclerosis were taken into consideration (women among multiple-6/10, 60.0%; among single-14/70, 20.0%; P=.01). Smoking was less reported in cases with multiple (4/14, 28.6%) than with single aneurysm (53/86, 61.6%; P=.04); considering cases with atherosclerosis, such difference decreases (40.0% of multiple versus 68.6% of single, P=.09). although atherosclerosis is present in most cases of both single and multiple aortic aneurysms, male gender and smoking, considered highly influential in such lesions, are less frequent in patients with multiple than in patients with single aneurysms. Thus mechanisms underlying multiple aortic aneurysms are probably different from those related to single, more common aneurysms. Copyright © 2015 Elsevier Inc. All rights reserved.
Holmes, Susan; Alekseyenko, Alexander; Timme, Alden; Nelson, Tyrrell; Pasricha, Pankaj Jay; Spormann, Alfred
2011-01-01
This article explains the statistical and computational methodology used to analyze species abundances collected using the LNBL Phylochip in a study of Irritable Bowel Syndrome (IBS) in rats. Some tools already available for the analysis of ordinary microarray data are useful in this type of statistical analysis. For instance in correcting for multiple testing we use Family Wise Error rate control and step-down tests (available in the multtest package). Once the most significant species are chosen we use the hypergeometric tests familiar for testing GO categories to test specific phyla and families. We provide examples of normalization, multivariate projections, batch effect detection and integration of phylogenetic covariation, as well as tree equalization and robustification methods.
Factor analysis and predictive validity of microcomputer-based tests
NASA Technical Reports Server (NTRS)
Kennedy, R. S.; Baltzley, D. R.; Turnage, J. J.; Jones, M. B.
1989-01-01
11 tests were selected from two microcomputer-based performance test batteries because previously these tests exhibited rapid stability (less than 10 min, of practice) and high retest reliability efficiencies (r greater than 0.707 for each 3 min. of testing). The battery was administered three times to each of 108 college students (48 men and 60 women) and a factor analysis was performed. Two of the three identified factors appear to be related to information processing ("encoding" and "throughput/decoding"), and the third named an "output/speed" factor. The spatial, memory, and verbal tests loaded on the "encoding" factor and included Grammatical Reasoning, Pattern Comparison, Continuous Recall, and Matrix Rotation. The "throughput/decoding" tests included perceptual/numerical tests like Math Processing, Code Substitution, and Pattern Comparison. The output speed factor was identified by Tapping and Reaction Time tests. The Wonderlic Personnel Test was group administered before the first and after the last administration of the performance tests. The multiple Rs in the total sample between combined Wonderlic as a criterion and less than 5 min. of microcomputer testing on Grammatical Reasoning and Math Processing as predictors ranged between 0.41 and 0.52 on the three test administrations. Based on these results, the authors recommend a core battery which, if time permits, would consist of two tests from each factor. Such a battery is now known to permit stable, reliable, and efficient assessment.
Werling, Donna M; Brand, Harrison; An, Joon-Yong; Stone, Matthew R; Zhu, Lingxue; Glessner, Joseph T; Collins, Ryan L; Dong, Shan; Layer, Ryan M; Markenscoff-Papadimitriou, Eirene; Farrell, Andrew; Schwartz, Grace B; Wang, Harold Z; Currall, Benjamin B; Zhao, Xuefang; Dea, Jeanselle; Duhn, Clif; Erdman, Carolyn A; Gilson, Michael C; Yadav, Rachita; Handsaker, Robert E; Kashin, Seva; Klei, Lambertus; Mandell, Jeffrey D; Nowakowski, Tomasz J; Liu, Yuwen; Pochareddy, Sirisha; Smith, Louw; Walker, Michael F; Waterman, Matthew J; He, Xin; Kriegstein, Arnold R; Rubenstein, John L; Sestan, Nenad; McCarroll, Steven A; Neale, Benjamin M; Coon, Hilary; Willsey, A Jeremy; Buxbaum, Joseph D; Daly, Mark J; State, Matthew W; Quinlan, Aaron R; Marth, Gabor T; Roeder, Kathryn; Devlin, Bernie; Talkowski, Michael E; Sanders, Stephan J
2018-05-01
Genomic association studies of common or rare protein-coding variation have established robust statistical approaches to account for multiple testing. Here we present a comparable framework to evaluate rare and de novo noncoding single-nucleotide variants, insertion/deletions, and all classes of structural variation from whole-genome sequencing (WGS). Integrating genomic annotations at the level of nucleotides, genes, and regulatory regions, we define 51,801 annotation categories. Analyses of 519 autism spectrum disorder families did not identify association with any categories after correction for 4,123 effective tests. Without appropriate correction, biologically plausible associations are observed in both cases and controls. Despite excluding previously identified gene-disrupting mutations, coding regions still exhibited the strongest associations. Thus, in autism, the contribution of de novo noncoding variation is probably modest in comparison to that of de novo coding variants. Robust results from future WGS studies will require large cohorts and comprehensive analytical strategies that consider the substantial multiple-testing burden.
Elias, Andrew; Crayton, Samuel H.; Warden-Rothman, Robert; Tsourkas, Andrew
2014-01-01
Given the rapidly expanding library of disease biomarkers and targeting agents, the number of unique targeted nanoparticles is growing exponentially. The high variability and expense of animal testing often makes it unfeasible to examine this large number of nanoparticles in vivo. This often leads to the investigation of a single formulation that performed best in vitro. However, nanoparticle performance in vivo depends on many variables, many of which cannot be adequately assessed with cell-based assays. To address this issue, we developed a lanthanide-doped nanoparticle method that allows quantitative comparison of multiple targeted nanoparticles simultaneously. Specifically, superparamagnetic iron oxide (SPIO) nanoparticles with different targeting ligands were created, each with a unique lanthanide dopant. Following the simultaneous injection of the various SPIO compositions into tumor-bearing mice, inductively coupled plasma mass spectroscopy was used to quantitatively and orthogonally assess the concentration of each SPIO composition in serial blood and resected tumor samples. PMID:25068300
Reduced-order modeling for hyperthermia control.
Potocki, J K; Tharp, H S
1992-12-01
This paper analyzes the feasibility of using reduced-order modeling techniques in the design of multiple-input, multiple-output (MIMO) hyperthermia temperature controllers. State space thermal models are created based upon a finite difference expansion of the bioheat transfer equation model of a scanned focused ultrasound system (SFUS). These thermal state space models are reduced using the balanced realization technique, and an order reduction criterion is tabulated. Results show that a drastic reduction in model dimension can be achieved using the balanced realization. The reduced-order model is then used to design a reduced-order optimal servomechanism controller for a two-scan input, two thermocouple output tissue model. In addition, a full-order optimal servomechanism controller is designed for comparison and validation purposes. These two controllers are applied to a variety of perturbed tissue thermal models to test the robust nature of the reduced-order controller. A comparison of the two controllers validates the use of open-loop balanced reduced-order models in the design of MIMO hyperthermia controllers.
Fitting Multimeric Protein Complexes into Electron Microscopy Maps Using 3D Zernike Descriptors
Esquivel-Rodríguez, Juan; Kihara, Daisuke
2012-01-01
A novel computational method for fitting high-resolution structures of multiple proteins into a cryoelectron microscopy map is presented. The method named EMLZerD generates a pool of candidate multiple protein docking conformations of component proteins, which are later compared with a provided electron microscopy (EM) density map to select the ones that fit well into the EM map. The comparison of docking conformations and the EM map is performed using the 3D Zernike descriptor (3DZD), a mathematical series expansion of three-dimensional functions. The 3DZD provides a unified representation of the surface shape of multimeric protein complex models and EM maps, which allows a convenient, fast quantitative comparison of the three dimensional structural data. Out of 19 multimeric complexes tested, near native complex structures with a root mean square deviation of less than 2.5 Å were obtained for 14 cases while medium range resolution structures with correct topology were computed for the additional 5 cases. PMID:22417139
Fitting multimeric protein complexes into electron microscopy maps using 3D Zernike descriptors.
Esquivel-Rodríguez, Juan; Kihara, Daisuke
2012-06-14
A novel computational method for fitting high-resolution structures of multiple proteins into a cryoelectron microscopy map is presented. The method named EMLZerD generates a pool of candidate multiple protein docking conformations of component proteins, which are later compared with a provided electron microscopy (EM) density map to select the ones that fit well into the EM map. The comparison of docking conformations and the EM map is performed using the 3D Zernike descriptor (3DZD), a mathematical series expansion of three-dimensional functions. The 3DZD provides a unified representation of the surface shape of multimeric protein complex models and EM maps, which allows a convenient, fast quantitative comparison of the three-dimensional structural data. Out of 19 multimeric complexes tested, near native complex structures with a root-mean-square deviation of less than 2.5 Å were obtained for 14 cases while medium range resolution structures with correct topology were computed for the additional 5 cases.
Omar, R Z; Morton, L S; Beirne, M; Blot, W J; Lawford, P V; Hose, R; Taylor, K M
2001-06-01
Björk-Shiley 60 degrees convexo-concave prosthetic heart valves (Shiley, Inc, Irvine, Calif, a subsidiary of Pfizer, Inc) continue to be a concern for approximately 35,000 nonexplanted patients worldwide, with approximately 600 events reported to the manufacturer to date. Fractures of the outlet struts of the valves began to appear in the early 1980s and have continued to the present, but their causes are only partially understood. A matched case-control study was conducted evaluating manufacturing records for 52 valves with outlet strut fractures and 248 control subjects matched for age at implantation, valve size, and valve position. In addition to the risk factors recognized as determinants of outlet strut fracture, the United Kingdom case-control study has observed 7- to 9-fold increased risk with performance of multiple hook deflection tests. This test was performed more than once, usually after rework on the valve. Six valves in this study underwent multiple hook deflection tests, of which 4 experienced an outlet strut fracture. Cracks and further rework were noted for these valves. Significant associations were also observed between outlet strut fracture and disc-to-strut gap measurements taken before the attachment of the sewing ring. It is our view that a combination of factors related to valve design, manufacturing process, and patient characteristics are responsible for outlet strut fractures of Björk-Shiley convexo-concave valves. Multiple hook deflection tests have emerged as a potential new risk factor for outlet strut fracture in both The Netherlands and the United Kingdom. This factor appears to be correlated with the presence of other abnormalities. A further study is needed to investigate the factors correlated with multiple hook deflection tests. On confirmation of risk, the presence of multiple hook deflection tests may be added to equations, quantifying the risk of outlet strut fracture for comparison against risk of mortality and serious morbidity from explant operations.
Using Comparison of Multiple Strategies in the Mathematics Classroom: Lessons Learned and Next Steps
ERIC Educational Resources Information Center
Durkin, Kelley; Star, Jon R.; Rittle-Johnson, Bethany
2017-01-01
Comparison is a fundamental cognitive process that can support learning in a variety of domains, including mathematics. The current paper aims to summarize empirical findings that support recommendations on using comparison of multiple strategies in mathematics classrooms. We report the results of our classroom-based research on using comparison…
Kono, Keiko; Shimizu, Yoshiki; Takahashi, Satomi; Matsuoka, Sayuri; Yui, Kei
2014-01-01
Objective The study aimed to verify that ingestion of multiple dietary supplement containing lutein, astaxanthin, cyanidin-3-glucoside and docosahexaenoic acid (DHA) would improve accommodative ability of aged and older subjects who were aware of eye strain on a daily basis. Methods A randomized double-blind placebo-controlled parallel group comparison study was conducted for 48 participants aged 45 to 64 years who complained of eye strain. The subjects took multiple dietary supplement containing 10 mg of lutein, 20 mg of bilberry extract and 26.5 mg of black soybean hull extract (a total of 2.3 mg of cyanidin-3-glucoside in both extracts), 4 mg of astaxanthin, and 50 mg of DHA (test supplement) or placebo for four consecutive weeks. Near-point accommodation (NPA) and subjective symptoms were evaluated both before and after four weeks’ intake. Results The variation of the NPA of both eyes from baseline to 4 weeks’ post-intake in the test supplement group was significantly higher than in the placebo group (1.321±0.394 diopter (D) in the test supplement group and 0.108±0.336 D in the placebo group, p=0.023). The multiple dietary supplement group showed improvement in the NPA. Regarding subjective symptoms, significant improvement of “stiff shoulders or neck” and “blurred vision” was also found in the test supplement group compared to the placebo group (p<0.05). There were no safety concerns in this study. Conclusion This study shows that multiple dietary supplement containing lutein, astaxanthin, cyanidin-3-glucoside, and DHA has effect to improve accommodative ability and subjective symptoms related to eye fatigue.
ERIC Educational Resources Information Center
Stuive, Ilse; Kiers, Henk A. L.; Timmerman, Marieke E.
2009-01-01
A common question in test evaluation is whether an a priori assignment of items to subtests is supported by empirical data. If the analysis results indicate the assignment of items to subtests under study is not supported by data, the assignment is often adjusted. In this study the authors compare two methods on the quality of their suggestions to…
Springer, Jan; White, P Lewis; Hamilton, Shanna; Michel, Denise; Barnes, Rosemary A; Einsele, Hermann; Löffler, Juergen
2016-03-01
Standardized methodologies for the molecular detection of invasive aspergillosis (IA) have been established by the European Aspergillus PCR Initiative for the testing of whole blood, serum, and plasma. While some comparison of the performance of Aspergillus PCR when testing these different sample types has been performed, no single study has evaluated all three using the recommended protocols. Standardized Aspergillus PCR was performed on 423 whole-blood pellets (WBP), 583 plasma samples, and 419 serum samples obtained from hematology patients according to the recommendations. This analysis formed a bicenter retrospective anonymous case-control study, with diagnosis according to the revised European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and National Institute of Allergy and Infectious Diseases Mycoses Study Group (EORTC/MSG) consensus definitions (11 probable cases and 36 controls). Values for clinical performance using individual and combined samples were calculated. For all samples, PCR positivity was significantly associated with cases of IA (for plasma, P = 0.0019; for serum, P = 0.0049; and for WBP, P = 0.0089). Plasma PCR generated the highest sensitivity (91%); the sensitivities for serum and WBP PCR were 80% and 55%, respectively. The highest specificity was achieved when testing WBP (96%), which was significantly superior to the specificities achieved when testing serum (69%, P = 0.0238) and plasma (53%, P = 0.0002). No cases were PCR negative in all specimen types, and no controls were PCR positive in all specimens. This study confirms that Aspergillus PCR testing of plasma provides robust performance while utilizing commercial automated DNA extraction processes. Combining PCR testing of different blood fractions allows IA to be both confidently diagnosed and excluded. A requirement for multiple PCR-positive plasma samples provides similar diagnostic utility and is technically less demanding. Time to diagnosis may be enhanced by testing multiple contemporaneously obtained sample types. Copyright © 2016, American Society for Microbiology. All Rights Reserved.
[Selenium metabolism in patients with severe multiple trauma].
Zaĭnudinov, Z M; Shabanov, A K; Zorin, S N; Kuzovlev, A N; Mal'tsev, G Iu; Azarov, Ia B; Vorozhko, I V; Grebenchikov, O A
2014-01-01
To define a relation between the selenium level and the risk of the development of nosocomial pneumonia in patients with severe multiple trauma depending on the trauma severity and the volume of blood loss. We measured serum selenium concentration in 40 patients with severe multiple trauma. The ISS score was used to estimate the trauma severity. Patients were divided into 2 groups: group I--25 patients without pneumonia, group II--15 patients with pneumonia. The volume of blood loss was estimated in each group. The oxidative stress was estimated by means of the antioxidant index. For selected groups the significant difference (P < 0.05) in the volume of blood loss was detected. It was shown the significant decrease of selenium concentration (P < 0.05) in both groups in comparison with control for all testing time points (the 6-12 hrs, 24 hrs, 3 and 5-7 days). The mean of selenium concentration in group II was significantly lower in comparison to the group I. A significant difference of selenium concentrations (P < 0.05) between groups were detected on the 6-12 hrs and day 3 from the trauma onset. The antioxidant index was significantly lower in the group II within the 6-12 hrs, 12-24 hrs and 5-7 days (P < 0.05) in comparison to group I. The severe multiple trauma and severe blood loss lead to a selenium deficiency in the blood serum starting with the first hours from the trauma onset, which leads to the critical level of selenium concentration by the Ist day's end after trauma. It also leads to a pronounced oxidative stress that is reflected in the antioxidant index dynamics. Thus serum selenium concentration may be included in the set of the early prognostic detectors to detect infectious pulmonary complications development at severe multiple trauma, and it could be the basis for the decision to take early prophylaxis using selenium medications.
Jacob, Robin; Somers, Marie-Andree; Zhu, Pei; Bloom, Howard
2016-06-01
In this article, we examine whether a well-executed comparative interrupted time series (CITS) design can produce valid inferences about the effectiveness of a school-level intervention. This article also explores the trade-off between bias reduction and precision loss across different methods of selecting comparison groups for the CITS design and assesses whether choosing matched comparison schools based only on preintervention test scores is sufficient to produce internally valid impact estimates. We conduct a validation study of the CITS design based on the federal Reading First program as implemented in one state using results from a regression discontinuity design as a causal benchmark. Our results contribute to the growing base of evidence regarding the validity of nonexperimental designs. We demonstrate that the CITS design can, in our example, produce internally valid estimates of program impacts when multiple years of preintervention outcome data (test scores in the present case) are available and when a set of reasonable criteria are used to select comparison organizations (schools in the present case). © The Author(s) 2016.
2013-01-01
Background Despite the widespread use of multiple-choice assessments in medical education assessment, current practice and published advice concerning the number of response options remains equivocal. This article describes an empirical study contrasting the quality of three 60 item multiple-choice test forms within the Royal Australian and New Zealand College of Obstetricians and Gynaecologists (RANZCOG) Fetal Surveillance Education Program (FSEP). The three forms are described below. Methods The first form featured four response options per item. The second form featured three response options, having removed the least functioning option from each item in the four-option counterpart. The third test form was constructed by retaining the best performing version of each item from the first two test forms. It contained both three and four option items. Results Psychometric and educational factors were taken into account in formulating an approach to test construction for the FSEP. The four-option test performed better than the three-option test overall, but some items were improved by the removal of options. The mixed-option test demonstrated better measurement properties than the fixed-option tests, and has become the preferred test format in the FSEP program. The criteria used were reliability, errors of measurement and fit to the item response model. Conclusions The position taken is that decisions about the number of response options be made at the item level, with plausible options being added to complete each item on both psychometric and educational grounds rather than complying with a uniform policy. The point is to construct the better performing item in providing the best psychometric and educational information. PMID:23453056
Zoanetti, Nathan; Beaves, Mark; Griffin, Patrick; Wallace, Euan M
2013-03-04
Despite the widespread use of multiple-choice assessments in medical education assessment, current practice and published advice concerning the number of response options remains equivocal. This article describes an empirical study contrasting the quality of three 60 item multiple-choice test forms within the Royal Australian and New Zealand College of Obstetricians and Gynaecologists (RANZCOG) Fetal Surveillance Education Program (FSEP). The three forms are described below. The first form featured four response options per item. The second form featured three response options, having removed the least functioning option from each item in the four-option counterpart. The third test form was constructed by retaining the best performing version of each item from the first two test forms. It contained both three and four option items. Psychometric and educational factors were taken into account in formulating an approach to test construction for the FSEP. The four-option test performed better than the three-option test overall, but some items were improved by the removal of options. The mixed-option test demonstrated better measurement properties than the fixed-option tests, and has become the preferred test format in the FSEP program. The criteria used were reliability, errors of measurement and fit to the item response model. The position taken is that decisions about the number of response options be made at the item level, with plausible options being added to complete each item on both psychometric and educational grounds rather than complying with a uniform policy. The point is to construct the better performing item in providing the best psychometric and educational information.
Kotańska, Magdalena; Lustyk, Klaudia; Bucki, Adam; Marcinkowska, Monika; Śniecikowska, Joanna; Kołaczkowski, Marcin
2018-06-01
Obesity, from early childhood onwards, is a common societal problem. The overconsumption of sweet, salty and high-fat products are the main factors that cause excessive weight gain. It is therefore necessary to search for new drugs that affect satiety centers and reduce the sense of hunger and caloric intake. It has been suggested that the blockade of 5-HT 6 receptors may reduce food intake, and since idalopirdine is a clinically tested, selective 5HT 6 receptor antagonist, it was chosen to be examined in animal models of obesity. The activity of idalopirdine was measured in the rat model of excessive eating. Animals were on a high caloric diet that consisted of milk chocolate with nuts, cheese, salted peanuts and condensed milk. During a four-week experiment, the rats had constant access to standard feed and water ad libitum. Idalopirdine was administered intraperitoneally at a dose 5 mg/kg b.w./day. To establish whether idalopirdine would effectively suppress the rebound hyperphagia that accompanies refeeding, it was administered after a 20 h food deprivation period. Pica behavior was evaluated after the administration of idalopirdine to confirm that the suppression of food intake was not caused by visceral illness. The effect of the four-week treatment with idalopirdine on the amount of peritoneal adipose tissue, and on lipid and carbohydrate profiles in rats was also examined. The statistical significance was calculated using the one-way ANOVA post-hoc Tukey Multiple Comparison Test or the two-way ANOVA post-hoc Bonferroni Multiple Comparison Test. Idalopirdine significantly reduced caloric intake and prevented the development of obesity in tested animals. Rats, that received idalopirdine, had a smaller amount of adipose tissue in the peritoneum as well as lower glucose, triglyceride and cholesterol levels in comparison to the control group. Moreover, an anorectic action was not caused by abnormalities of the gastrointestinal tract, such as nausea. The obtained results indicate that idalopirdine reduces caloric intake and could be considered for further tests as a potential treatment of obesity.
Vazquez, Bruna Perez; Vazquez, Thaís Perez; Miguel, Camila Botelho; Rodrigues, Wellington Francisco; Mendes, Maria Tays; de Oliveira, Carlo José Freire; Chica, Javier Emílio Lazo
2015-04-03
Chagas disease is caused by the protozoan Trypanosoma cruzi and is characterized by cardiac, gastrointestinal, and nervous system disorders. Although much about the pathophysiological process of Chagas disease is already known, the influence of the parasite burden on the inflammatory process and disease progression remains uncertain. We used an acute experimental disease model to evaluate the effect of T. cruzi on intestinal lesions and assessed correlations between parasite load and inflammation and intestinal injury at 7 and 14 days post-infection. Low (3 × 10(2)), medium (3 × 10(3)), and high (3 × 10(4)) parasite loads were generated by infecting C57BL/6 mice with "Y"-strain trypomastigotes. Statistical analysis was performed using analysis of variance with Tukey's multiple comparison post-test, Kruskal-Wallis test with Dunn's multiple comparison, χ2 test and Spearman correlation. High parasite load-bearing mice more rapidly and strongly developed parasitemia. Increased colon width, inflammatory infiltration, myositis, periganglionitis, ganglionitis, pro-inflammatory cytokines (e.g., TNF-α, INF-γ, IL-2, IL-17, IL-6), and intestinal amastigote nests were more pronounced in high parasite load-bearing animals. These results were remarkable because a positive correlation was observed between parasite load, inflammatory infiltrate, amastigote nests, and investigated cytokines. These experimental data support the idea that the parasite load considerably influences the T. cruzi-induced intestinal inflammatory response and contributes to the development of the digestive form of the disease.
NASA Technical Reports Server (NTRS)
Tacina, K. M.; Hicks, Y. R.
2017-01-01
The combustion dynamics of multiple 7-point lean direct injection (LDI) combustor configurations are compared. LDI is a fuel-lean combustor concept for aero gas turbine engines in which multiple small fuel-air mixers replace one traditionally-sized fuel-air mixer. This 7-point LDI configuration has a circular cross section, with a center (pilot) fuel-air mixer surrounded by six outer (main) fuel-air mixers. Each fuel-air mixer consists of an axial air swirler followed by a converging-diverging venturi. A simplex fuel injector is inserted through the center of the air swirler, with the fuel injector tip located near the venturi throat. All 7 fuel-air mixers are identical except for the swirler blade angle, which varies with the configuration. Testing was done in a 5-atm flame tube with inlet air temperatures from 600 to 800 F and equivalence ratios from 0.4 to 0.7. Combustion dynamics were measured using a cooled PCB pressure transducer flush-mounted in the wall of the combustor test section.
Assessment of bifacial photovoltaic module power rating methodologies–inside and out
Deline, Chris; MacAlpine, Sara; Marion, Bill; ...
2017-01-26
One-sun power ratings for bifacial modules are currently undefined. This is partly because there is no standard definition of rear irradiance given 1000 W·m -2 on the front. Using field measurements and simulations, we evaluate multiple deployment scenarios for bifacial modules and provide details on the amount of irradiance that could be expected. A simplified case that represents a single module deployed under conditions consistent with existing one-sun irradiance standards lead to a bifacial reference condition of 1000 W·m -2 G front and 130-140 W·m -2 G rear. For fielded systems of bifacial modules, Grear magnitude and spatial uniformity willmore » be affected by self-shade from adjacent modules, varied ground cover, and ground-clearance height. A standard measurement procedure for bifacial modules is also currently undefined. A proposed international standard is under development, which provides the motivation for this paper. Here, we compare field measurements of bifacial modules under natural illumination with proposed indoor test methods, where irradiance is only applied to one side at a time. The indoor method has multiple advantages, including controlled and repeatable irradiance and thermal environment, along with allowing the use of conventional single-sided flash test equipment. The comparison results are promising, showing that indoor and outdoor methods agree within 1%-2% for multiple rear-irradiance conditions and bifacial module construction. Furthermore, a comparison with single-diode theory also shows good agreement to indoor measurements, within 1%-2% for power and other current-voltage curve parameters.« less
PRESAGE: PRivacy-preserving gEnetic testing via SoftwAre Guard Extension.
Chen, Feng; Wang, Chenghong; Dai, Wenrui; Jiang, Xiaoqian; Mohammed, Noman; Al Aziz, Md Momin; Sadat, Md Nazmus; Sahinalp, Cenk; Lauter, Kristin; Wang, Shuang
2017-07-26
Advances in DNA sequencing technologies have prompted a wide range of genomic applications to improve healthcare and facilitate biomedical research. However, privacy and security concerns have emerged as a challenge for utilizing cloud computing to handle sensitive genomic data. We present one of the first implementations of Software Guard Extension (SGX) based securely outsourced genetic testing framework, which leverages multiple cryptographic protocols and minimal perfect hash scheme to enable efficient and secure data storage and computation outsourcing. We compared the performance of the proposed PRESAGE framework with the state-of-the-art homomorphic encryption scheme, as well as the plaintext implementation. The experimental results demonstrated significant performance over the homomorphic encryption methods and a small computational overhead in comparison to plaintext implementation. The proposed PRESAGE provides an alternative solution for secure and efficient genomic data outsourcing in an untrusted cloud by using a hybrid framework that combines secure hardware and multiple crypto protocols.
Erdem, Murat; Bolu, Abdullah; Ünlü, A Gazi; Alper, Mustafa; Yetkin, Sinan
2013-09-01
Both narcolepsy and idiopathic hypersomnia are the main causes of excessive daytime sleepiness. In this study, we aimed to compare polysomnography (PSG) and multiple sleep latency test (MSLT) findings in narcolepsy and idiopathic hypersomnia patients. The files of patients with narcolepsy and hypersomnia who were admitted between 1995 and 2009 were reviewed. We evaluated data from 94 patients with narcolepsy with cataplexy, 49 with narcolepsy without cataplexy and 140 patients with idiopathic hypersomnia. Sleep latency and REM latency were longer in idiopathic hypersomnia group than in narcolepsy with and without cataplexy group. Mean sleep latency in MSLT was the shortest in narcolepsy with cataplexy group. There was no difference in sleep efficiency, percentage of sleep stage and number of awakenings in PSG between three groups. The findings of the study indicated that narcolepsy patients differ from idiopathic hypersomnia patients in terms of sleep latency and REM latency in PSG.
Kang, Kyung-Ah; Kim, Shin-Jeong; Kaneko, Noriyo
2017-12-01
In this study, we identified the factors influencing behavioral intention to undergo Papanicolaou testing among Japanese and Korean women in early adulthood. Their behavioral intentions were compared in this cross-sectional descriptive study. In total, 887 women (Japanese = 498, Korean = 389) aged 20-39 years participated in this study. Using a self-report questionnaire, knowledge, attitudes, subjective norm, perceived behavioral control, and behavioral intention were surveyed. There were significant differences between Japanese and Korean women's scores on all main variables. For Japanese women, all the variables moderately correlated with behavioral intention. In comparison, for Korean women, all independent variables, except for knowledge, moderately correlated with behavioral intention. Through a multiple regression analysis, age, undergoing Papanicolaou testing, attitudes, subjective norm, and perceived behavioral control were identified as significant predictors of behavioral intention among Japanese women. Among Korean women, job status, undergoing a Papanicolaou test, attitudes, subjective norm, and perceived behavioral control were demonstrated as significant predictors of behavioral intention. Health professionals should consider these factors to encourage Papanicolaou testing in women in early adulthood. © 2017 John Wiley & Sons Australia, Ltd.
Kurup, Ravi Kumar; Kurup, Paramesware Achutha
2003-12-01
This study assessed the changes in the isoprenoid pathway and its metabolites digoxin, dolichol, and ubiquinone in multiple myeloma. The isoprenoid pathway and digoxin status were also studied for comparison in individuals of differing hemispheric dominance to find out the rote of cerebral dominance in the genesis of multiple myeloma and neoplasms. The following parameters were assessed: isoprenoid pathway metabolites, tyrosine and tryptophan catabolites, glycoconjugate metabolism, RBC membrane composition, and free radical metabolism--in multiple myeloma, as well as in individuals of differing hemispheric dominance. There was elevation in plasma HMG CoA reductase activity, serum digoxin, and dolichol, and a reduction in RBC membrane Na(+)-K+ ATPase activity, serum ubiquinone, and magnesium levels. Serum tryptophan, serotonin, nicotine, strychnine, and quinolinic acid were elevated, while tyrosine, dopamine, noradrenaline, and morphine were decreased. The total serum glycosaminoglycans and glycosaminoglycan fractions, the activity of GAG degrading enzymes and glycohydrolases, carbohydrate residues of glycoproteins, and serum glycolipids were elevated. The RBC membrane glycosaminoglycans, hexose, and fucose residues of glycoproteins, cholesterol, and phospholipids were reduced. The activity of all free-radical scavenging enzymes, concentration of glutathione, iron binding capacity, and ceruloplasmin decreased significantly, while the concentration of lipid peroxidation products and nitric oxide increased. Hyperdigoxinemia-related altered intracellular Ca++/Mg++ ratios mediated oncogene activation, dolichol-induced altered glycoconjugate metabolism, and ubiquinone deficiency-related mitochondrial dysfunction can contribute to the pathogenesis of multiple myeloma. The biochemical patterns obtained in multiple myeloma are similar to those obtained in left-handed/right hemispheric chemically dominant individuals by the dichotic listening test. But all the patients with multiple myeloma were right-handed/left hemispheric dominant by the dichotic listening test. Hemispheric chemical dominance has no correlation with handedness or the dichotic listening test. Multiple myeloma occurs in right hemispheric chemically dominant individuals and is a reflection of altered brain function.
NASA Astrophysics Data System (ADS)
Menne, Matthew J.; Williams, Claude N., Jr.
2005-10-01
An evaluation of three hypothesis test statistics that are commonly used in the detection of undocumented changepoints is described. The goal of the evaluation was to determine whether the use of multiple tests could improve undocumented, artificial changepoint detection skill in climate series. The use of successive hypothesis testing is compared to optimal approaches, both of which are designed for situations in which multiple undocumented changepoints may be present. In addition, the importance of the form of the composite climate reference series is evaluated, particularly with regard to the impact of undocumented changepoints in the various component series that are used to calculate the composite.In a comparison of single test changepoint detection skill, the composite reference series formulation is shown to be less important than the choice of the hypothesis test statistic, provided that the composite is calculated from the serially complete and homogeneous component series. However, each of the evaluated composite series is not equally susceptible to the presence of changepoints in its components, which may be erroneously attributed to the target series. Moreover, a reference formulation that is based on the averaging of the first-difference component series is susceptible to random walks when the composition of the component series changes through time (e.g., values are missing), and its use is, therefore, not recommended. When more than one test is required to reject the null hypothesis of no changepoint, the number of detected changepoints is reduced proportionately less than the number of false alarms in a wide variety of Monte Carlo simulations. Consequently, a consensus of hypothesis tests appears to improve undocumented changepoint detection skill, especially when reference series homogeneity is violated. A consensus of successive hypothesis tests using a semihierarchic splitting algorithm also compares favorably to optimal solutions, even when changepoints are not hierarchic.
Duque, P; Ibanez, J; Del Barco, A; Sepulcre, J; de Ramon, E; Fernandez-Fernandez, O
2012-03-01
INTRODUCTION. The current batteries such as the Brief Repeatable Battery of Neuropsychological Tests (BRB-N) for evaluating cognitive decline in patients with multiple sclerosis are complex and time-consuming. AIM. To obtain normative values and validate a new battery. SUBJECTS AND METHODS. Four neuropsychological tests were finally included (episodic memory, the Symbol-Digit Modalities Test, a category fluency test, and the Paced Auditory Serial Addition Test). Normative values (overall and by age group) were derived by administering the battery to healthy subjects (5th percentile was the limit of normal). External validity was explored by comparison with the BRB-N. The new battery was also administered to a subsample after 4 weeks to assess reproducibility. RESULTS. To provide normative data, 1036 healthy subjects were recruited. The mean completion time was 18.5 ± 5.2 minutes. For the 229 subjects who were administered the new battery and the BRB-N, no statistically significant differences were found except for mean completion time (19 ± 4 vs 25 ± 5 minutes). In the reproducibility study, there were no significant differences except in the memory tests. CONCLUSION. The scores on the new battery and the BRB-N were strongly correlated although the shorter completion time and ease of administration could make the new battery preferable in clinical practice.
NASA Astrophysics Data System (ADS)
Barniol, Pablo; Zavala, Genaro
2016-06-01
In this article we present several modifications of the mechanical waves conceptual survey, the most important test to date that has been designed to evaluate university students' understanding of four main topics in mechanical waves: propagation, superposition, reflection, and standing waves. The most significant changes are (i) modification of several test questions that had some problems in their original design, (ii) standardization of the number of options for each question to five, (iii) conversion of the two-tier questions to multiple-choice questions, and (iv) modification of some questions to make them independent of others. To obtain a final version of the test, we administered both the original and modified versions several times to students at a large private university in Mexico. These students were completing a course that covers the topics tested by the survey. The final modified version of the test was administered to 234 students. In this study we present the modifications for each question, and discuss the reasons behind them. We also analyze the results obtained by the final modified version and offer a comparison between the original and modified versions. In the Supplemental Material we present the final modified version of the test. It can be used by teachers and researchers to assess students' understanding of, and learning about, mechanical waves.
CR-Calculus and adaptive array theory applied to MIMO random vibration control tests
NASA Astrophysics Data System (ADS)
Musella, U.; Manzato, S.; Peeters, B.; Guillaume, P.
2016-09-01
Performing Multiple-Input Multiple-Output (MIMO) tests to reproduce the vibration environment in a user-defined number of control points of a unit under test is necessary in applications where a realistic environment replication has to be achieved. MIMO tests require vibration control strategies to calculate the required drive signal vector that gives an acceptable replication of the target. This target is a (complex) vector with magnitude and phase information at the control points for MIMO Sine Control tests while in MIMO Random Control tests, in the most general case, the target is a complete spectral density matrix. The idea behind this work is to tailor a MIMO random vibration control approach that can be generalized to other MIMO tests, e.g. MIMO Sine and MIMO Time Waveform Replication. In this work the approach is to use gradient-based procedures over the complex space, applying the so called CR-Calculus and the adaptive array theory. With this approach it is possible to better control the process performances allowing the step-by-step Jacobian Matrix update. The theoretical bases behind the work are followed by an application of the developed method to a two-exciter two-axis system and by performance comparisons with standard methods.
Hobart, J; Cano, S
2009-02-01
In this monograph we examine the added value of new psychometric methods (Rasch measurement and Item Response Theory) over traditional psychometric approaches by comparing and contrasting their psychometric evaluations of existing sets of rating scale data. We have concentrated on Rasch measurement rather than Item Response Theory because we believe that it is the more advantageous method for health measurement from a conceptual, theoretical and practical perspective. Our intention is to provide an authoritative document that describes the principles of Rasch measurement and the practice of Rasch analysis in a clear, detailed, non-technical form that is accurate and accessible to clinicians and researchers in health measurement. A comparison was undertaken of traditional and new psychometric methods in five large sets of rating scale data: (1) evaluation of the Rivermead Mobility Index (RMI) in data from 666 participants in the Cannabis in Multiple Sclerosis (CAMS) study; (2) evaluation of the Multiple Sclerosis Impact Scale (MSIS-29) in data from 1725 people with multiple sclerosis; (3) evaluation of test-retest reliability of MSIS-29 in data from 150 people with multiple sclerosis; (4) examination of the use of Rasch analysis to equate scales purporting to measure the same health construct in 585 people with multiple sclerosis; and (5) comparison of relative responsiveness of the Barthel Index and Functional Independence Measure in data from 1400 people undergoing neurorehabilitation. Both Rasch measurement and Item Response Theory are conceptually and theoretically superior to traditional psychometric methods. Findings from each of the five studies show that Rasch analysis is empirically superior to traditional psychometric methods for evaluating rating scales, developing rating scales, analysing rating scale data, understanding and measuring stability and change, and understanding the health constructs we seek to quantify. There is considerable added value in using Rasch analysis rather than traditional psychometric methods in health measurement. Future research directions include the need to reproduce our findings in a range of clinical populations, detailed head-to-head comparisons of Rasch analysis and Item Response Theory, and the application of Rasch analysis to clinical practice.
Brooks, M.H.; Schroder, L.J.; Malo, B.A.
1985-01-01
Four laboratories were evaluated in their analysis of identical natural and simulated precipitation water samples. Interlaboratory comparability was evaluated using analysis of variance coupled with Duncan 's multiple range test, and linear-regression models describing the relations between individual laboratory analytical results for natural precipitation samples. Results of the statistical analyses indicate that certain pairs of laboratories produce different results when analyzing identical samples. Analyte bias for each laboratory was examined using analysis of variance coupled with Duncan 's multiple range test on data produced by the laboratories from the analysis of identical simulated precipitation samples. Bias for a given analyte produced by a single laboratory has been indicated when the laboratory mean for that analyte is shown to be significantly different from the mean for the most-probable analyte concentrations in the simulated precipitation samples. Ion-chromatographic methods for the determination of chloride, nitrate, and sulfate have been compared with the colorimetric methods that were also in use during the study period. Comparisons were made using analysis of variance coupled with Duncan 's multiple range test for means produced by the two methods. Analyte precision for each laboratory has been estimated by calculating a pooled variance for each analyte. Analyte estimated precisions have been compared using F-tests and differences in analyte precisions for laboratory pairs have been reported. (USGS)
Tanigawa, Makoto; Stein, Jason; Park, John; Kosa, Peter; Cortese, Irene; Bielekova, Bibiana
2017-01-01
While magnetic resonance imaging contrast-enhancing lesions represent an excellent screening tool for disease-modifying treatments in relapsing-remitting multiple sclerosis (RRMS), this biomarker is insensitive for testing therapies against compartmentalized inflammation in progressive multiple sclerosis (MS). Therefore, alternative sensitive outcomes are needed. Using machine learning, clinician-acquired disability scales can be combined with timed measures of neurological functions such as walking speed (e.g. 25-foot walk; 25FW) or fine finger movements (e.g. 9-hole peg test; 9HPT) into sensitive composite clinical scales, such as the recently developed combinatorial, weight-adjusted disability scale (CombiWISE). Ideally, these complementary simplified measurements of certain neurological functions could be performed regularly at patients' homes using smartphones. We asked whether tests amenable to adaptation to smartphone technology, such as finger and foot tapping have comparable sensitivity and specificity to current non-clinician-acquired disability measures. We observed that finger and foot tapping can differentiate RRMS and progressive MS in a cross-sectional study and can also measure yearly and two-year disease progression in the latter, with better power (based on z-scores) in comparison to currently utilized 9HPT and 25FW. Replacing the 9HPT and 25FW with simplified tests broadly adaptable to smartphone technology may enhance the power of composite scales for progressive MS.
Kim, Tae Jung; Goo, Jin Mo; Lee, Kyung Won; Park, Chang Min; Lee, Hyun Ju
2009-05-01
To retrospectively compare the clinical, pathological, and thin-section CT features of persistent multiple ground-glass opacity (GGO) nodules with those of solitary GGO nodules. Histopathologic specimens were obtained from 193 GGO nodules in 136 patients (87 women, 49 men; mean age, 57; age range 33-81). The clinical data, pathologic findings, and thin-section CT features of multiple and solitary GGO nodules were compared by using t-test or Fisher's exact test. Multiple GGO nodules (n=105) included atypical adenomatous hyperplasia (AAH) (n=31), bronchioloalveolar carcinoma (BAC) (n=33), adenocarcinoma (n=34) and focal interstitial fibrosis (n=7). Solitary GGO nodules included AAH (n=8), BAC (n=15), adenocarcinoma (n=55) and focal interstitial fibrosis (n=10). AAH (P=.001) and BAC (P=.029) were more frequent in multiple GGO nodules, whereas adenocarcinoma (P<.001) was more frequent in solitary GGO nodules. Female sex (P<.001), nonsmoker (P=.012) and multiple primary lung cancers (P<.001) were more frequent for multiple GGO nodules, which were smaller (12 mm+/-7.9) than solitary GGO nodules (17 mm+/-8.1) (P<.001). Air-bronchogram (P=.019), bubble-lucency (P=.004), and pleural retraction (P<.001) were more frequent in solitary GGO nodules. There was no postoperative recurrence except for one patient with multiple GGO nodules and one with solitary GGO nodule. Clinical, pathological, and thin-section CT features of persistent multiple GGO nodules were found to differ from those of solitary GGO nodules. Nevertheless, the two nodule types can probably be followed up and managed in a similar manner because their prognoses were found to be similar.
Sisto, Dario; Trojano, Maria; Vetrugno, Michele; Trabucco, Tiziana; Iliceto, Giovanni; Sborgia, Carlo
2005-04-01
To evaluate the effectiveness of visual evoked potentials (VEPs), frequency-doubling perimetry (FDP), standard achromatic perimetry (SAP), contrast sensitivity (CS) test, and magnetic resonance imaging (MRI), isolated or in combination, in detecting subclinical impairment of visual function in multiple sclerosis (MS). Twenty-two eyes of 11 patients affected by clinically definite MS, without a history of optic neuritis and asymptomatic for visual disturbances, underwent full ophthalmic examination and, in addition, VEPs, FDP, SAP, CS, and MRI. Abnormal results were taken to be as follows: for VEPs, a P100 latency >115 ms; for FDP, abnormal mean deviation (MD) or pattern SD (PSD); for SAP, abnormal MD or PSD; for CS, abnormal CS at one spatial frequency, at least; and for MRI, evidence of at least one demyelinating plaque along the visual pathway. VEPs showed abnormal results in 12 eyes (54.4%), FDP in 11 (50%), SAP in 14 (63.6%), CS in 17 (77.1%), and MRI in 16 (72.7%). In only two (9.1%) eyes of the same patient was no abnormality found. No single test detected all the abnormal eyes. Four (18.2%) eyes had pure optic nerve involvement and the remaining 16 (72.7%) had both pre- and postchiasmal involvement. In patients affected by clinically definite MS without history of optic neuritis and no visual symptoms, there is a large prevalence of visual pathway involvement that can be diagnosed only by performing multiple tests. The comparison of the tests is also useful to detect the presence of multiple lesions in the same patient.
Propulsion Diagnostic Method Evaluation Strategy (ProDiMES) User's Guide
NASA Technical Reports Server (NTRS)
Simon, Donald L.
2010-01-01
This report is a User's Guide for the Propulsion Diagnostic Method Evaluation Strategy (ProDiMES). ProDiMES is a standard benchmarking problem and a set of evaluation metrics to enable the comparison of candidate aircraft engine gas path diagnostic methods. This Matlab (The Mathworks, Inc.) based software tool enables users to independently develop and evaluate diagnostic methods. Additionally, a set of blind test case data is also distributed as part of the software. This will enable the side-by-side comparison of diagnostic approaches developed by multiple users. The Users Guide describes the various components of ProDiMES, and provides instructions for the installation and operation of the tool.
A Simple Illustration for the Need of Multiple Comparison Procedures
ERIC Educational Resources Information Center
Carter, Rickey E.
2010-01-01
Statistical adjustments to accommodate multiple comparisons are routinely covered in introductory statistical courses. The fundamental rationale for such adjustments, however, may not be readily understood. This article presents a simple illustration to help remedy this.
Li, Zhiguang; Kwekel, Joshua C; Chen, Tao
2012-01-01
Functional comparison across microarray platforms is used to assess the comparability or similarity of the biological relevance associated with the gene expression data generated by multiple microarray platforms. Comparisons at the functional level are very important considering that the ultimate purpose of microarray technology is to determine the biological meaning behind the gene expression changes under a specific condition, not just to generate a list of genes. Herein, we present a method named percentage of overlapping functions (POF) and illustrate how it is used to perform the functional comparison of microarray data generated across multiple platforms. This method facilitates the determination of functional differences or similarities in microarray data generated from multiple array platforms across all the functions that are presented on these platforms. This method can also be used to compare the functional differences or similarities between experiments, projects, or laboratories.
A Methodological Inter-Comparison of Gridded Meteorological Products
NASA Astrophysics Data System (ADS)
Newman, A. J.; Clark, M. P.; Longman, R. J.; Giambelluca, T. W.; Arnold, J.
2017-12-01
Here we present a gridded meteorology inter-comparison using the state of Hawaíi as a testbed. This inter-comparison is motivated by two general goals: 1) the broad user community of gridded observation based meteorological fields should be aware of inter-product differences and the reasons they exist, which allows users to make informed choices on product selection to best meet their specific application(s); 2) we want to demonstrate the utility of inter-comparisons to meet the first goal, yet highlight that they are limited to mostly generic statements regarding attribution of differences that limits our understanding of these complex algorithms and obscures future research directions. Hawaíi is a useful testbed because it is a meteorologically complex region with well-known spatial features that are tied to specific physical processes (e.g. the trade wind inversion). From a practical standpoint, there are now several monthly climatological and daily precipitation and temperature datasets available that are being used for impact modeling. General conclusions that have emerged are: 1) differences in input station data significantly influence product differences; 2) prediction of precipitation occurrence is crucial across multiple metrics; 3) derived temperature statistics (e.g. diurnal temperature range) may have large spatial differences across products; and 4) attribution of differences to methodological choices is difficult and may limit the outcomes of these inter-comparisons, particularly from a development viewpoint. Thus, we want to continue to move the community towards frameworks that allow for multiple options throughout the product generation chain and allow for more systematic testing.
Genetic and Environmental Influences of General Cognitive Ability: Is g a valid latent construct?
Panizzon, Matthew S.; Vuoksimaa, Eero; Spoon, Kelly M.; Jacobson, Kristen C.; Lyons, Michael J.; Franz, Carol E.; Xian, Hong; Vasilopoulos, Terrie; Kremen, William S.
2014-01-01
Despite an extensive literature, the “g” construct remains a point of debate. Different models explaining the observed relationships among cognitive tests make distinct assumptions about the role of g in relation to those tests and specific cognitive domains. Surprisingly, these different models and their corresponding assumptions are rarely tested against one another. In addition to the comparison of distinct models, a multivariate application of the twin design offers a unique opportunity to test whether there is support for g as a latent construct with its own genetic and environmental influences, or whether the relationships among cognitive tests are instead driven by independent genetic and environmental factors. Here we tested multiple distinct models of the relationships among cognitive tests utilizing data from the Vietnam Era Twin Study of Aging (VETSA), a study of middle-aged male twins. Results indicated that a hierarchical (higher-order) model with a latent g phenotype, as well as specific cognitive domains, was best supported by the data. The latent g factor was highly heritable (86%), and accounted for most, but not all, of the genetic effects in specific cognitive domains and elementary cognitive tests. By directly testing multiple competing models of the relationships among cognitive tests in a genetically-informative design, we are able to provide stronger support than in prior studies for g being a valid latent construct. PMID:24791031
Gram-Negative Bacterial Wound Infections
2015-05-01
not statistically differ- ent from that of the control group . The levels (CFU/g) of bacteria in lung tissue correlated with the survival curves. The...median levels in the control and 2.5 mg/kg- treated groups were almost identical, at 9.04 and 9.07 log CFU/g, respectively. Figure 6B shows a decrease...Dunn’s multiple comparison test, found a statistically significant difference in bacterial burden when the control group was com- pared to animals
Multiple Case Comparison of the In-Transit Visibility Business Process
2003-03-01
therefore we give it the highest levels of development , testing, training, continuous improvement (lessons learned ) with all of the staff. b. How do you... the Air Force. Results from this study indicate that a lack of emphasis on policy development and management practices, rather than poor system...frequently require information on what they will receive, not just when they will receive it (Gilmore, 2002). This shift in strategy makes the study
Verloock, Leen; Joseph, Wout; Gati, Azeddine; Varsier, Nadège; Flach, Björn; Wiart, Joe; Martens, Luc
2013-06-01
An experimental validation of a low-cost method for extrapolation and estimation of the maximal electromagnetic-field exposure from long-term evolution (LTE) radio base station installations are presented. No knowledge on downlink band occupation or service characteristics is required for the low-cost method. The method is applicable in situ. It only requires a basic spectrum analyser with appropriate field probes without the need of expensive dedicated LTE decoders. The method is validated both in laboratory and in situ, for a single-input single-output antenna LTE system and a 2×2 multiple-input multiple-output system, with low deviations in comparison with signals measured using dedicated LTE decoders.
Behrangrad, Shabnam; Kordi Yoosefinejad, Amin
2018-03-01
The purpose of this study is to investigate the validity and reliability of the Persian version of the Multidimensional Assessment of Fatigue Scale (MAFS) in an Iranian population with multiple sclerosis. A self-reported survey on fatigue including the MAFS, Fatigue Impact Scale and demographic measures was completed by 130 patients with multiple sclerosis and 60 healthy persons sampled with a convenience method. Test-retest reliability and validity were evaluated 3 days apart. Construct validity of the MAFS was assessed with the Fatigue Impact Scale. The MAFS had high internal consistency (Cronbach's alpha >0.9) and 3-d test-retest reliability (intraclass correlation coefficient = 0.99). Correlation between the Fatigue Impact Scale and MAFS was high (r = 0.99). Correlation between MAFS scores and the Expanded Disability Status Scale was also strong (r = 0.85). Questionnaire items showed acceptable item-scale correlation (0.968-0.993). The Persian version of the MAFS appears to be a valid and reliable questionnaire. It is an appropriate short multidimensional instrument to assess fatigue in patients with multiple sclerosis in clinical practice and research. Implications for Rehabilitation The Persian version of Multidimensional Assessment of Fatigue is a valid and reliable instrument for the assessment and monitoring the fatigue in Persian-language patients with multiple sclerosis. It is very easy to administer and a time efficient scale in comparison to other instruments evaluating fatigue in patients with multiple sclerosis.
Comparisons of MOVES Light-duty Gasoline NOx Emission Rates with Real-world Measurements
NASA Astrophysics Data System (ADS)
Choi, D.; Sonntag, D.; Warila, J.
2017-12-01
Recent studies have shown differences between air quality model estimates and monitored values for nitrogen oxides. Several studies have suggested that the discrepancy between monitored and modeled values is due to an overestimation of NOx from mobile sources in EPA's emission inventory, particularly for light-duty gasoline vehicles. EPA's MOtor Vehicle Emission Simulator (MOVES) is an emission modeling system that estimates emissions for cars, trucks and other mobile sources at the national, county, and project level for criteria pollutants, greenhouse gases, and air toxics. Studies that directly measure vehicle emissions provide useful data for evaluating MOVES when the measurement conditions are properly accounted for in modeling. In this presentation, we show comparisons of MOVES2014 to thousands of real-world NOx emissions measurements from individual light-duty gasoline vehicles. The comparison studies include in-use vehicle emissions tests conducted on chassis dynamometer tests in support of Denver, Colorado's Vehicle Inspection & Maintenance Program and remote sensing data collected using road-side instruments in multiple locations and calendar years in the United States. In addition, we conduct comparisons of MOVES predictions to fleet-wide emissions measured from tunnels. We also present details on the methodology used to conduct the MOVES model runs in comparing to the independent data.
Analysis and Testing of Mobile Wireless Networks
NASA Technical Reports Server (NTRS)
Alena, Richard; Evenson, Darin; Rundquist, Victor; Clancy, Daniel (Technical Monitor)
2002-01-01
Wireless networks are being used to connect mobile computing elements in more applications as the technology matures. There are now many products (such as 802.11 and 802.11b) which ran in the ISM frequency band and comply with wireless network standards. They are being used increasingly to link mobile Intranet into Wired networks. Standard methods of analyzing and testing their performance and compatibility are needed to determine the limits of the technology. This paper presents analytical and experimental methods of determining network throughput, range and coverage, and interference sources. Both radio frequency (BE) domain and network domain analysis have been applied to determine wireless network throughput and range in the outdoor environment- Comparison of field test data taken under optimal conditions, with performance predicted from RF analysis, yielded quantitative results applicable to future designs. Layering multiple wireless network- sooners can increase performance. Wireless network components can be set to different radio frequency-hopping sequences or spreading functions, allowing more than one sooner to coexist. Therefore, we ran multiple 802.11-compliant systems concurrently in the same geographical area to determine interference effects and scalability, The results can be used to design of more robust networks which have multiple layers of wireless data communication paths and provide increased throughput overall.
De Cola, Maria Cristina; D'Aleo, Giangaetano; Sessa, Edoardo; Marino, Silvia
2015-01-01
Objective. To investigate the influence of demographic and clinical variables, such as depression, fatigue, and quantitative MRI marker on cognitive performances in a sample of patients affected by multiple sclerosis (MS). Methods. 60 MS patients (52 relapsing remitting and 8 primary progressive) underwent neuropsychological assessments using Rao's Brief Repeatable Battery of Neuropsychological Tests (BRB-N), the Beck Depression Inventory-second edition (BDI-II), and the Fatigue Severity Scale (FSS). We performed magnetic resonance imaging to all subjects using a 3 T scanner and obtained tissue-specific volumes (normalized brain volume and cortical brain volume). We used Student's t-test to compare depressed and nondepressed MS patients. Finally, we performed a multivariate regression analysis in order to assess possible predictors of patients' cognitive outcome among demographic and clinical variables. Results. 27.12% of the sample (16/59) was cognitively impaired, especially in tasks requiring attention and information processing speed. From between group comparison, we find that depressed patients had worse performances on BRB-N score, greater disability and disease duration, and brain volume decrease. According to multiple regression analysis, the BDI-II score was a significant predictor for most of the neuropsychological tests. Conclusions. Our findings suggest that the presence of depressive symptoms is an important determinant of cognitive performance in MS patients. PMID:25861633
Ground vibration test results of a JetStar airplane using impulsive sine excitation
NASA Technical Reports Server (NTRS)
Kehoe, Michael W.; Voracek, David F.
1989-01-01
Structural excitation is important for both ground vibration and flight flutter testing. The structural responses caused by this excitation are analyzed to determine frequency, damping, and mode shape information. Many excitation waveforms have been used throughout the years. The use of impulsive sine (sin omega t)/omega t as an excitation waveform for ground vibration testing and the advantages of using this waveform for flight flutter testing are discussed. The ground vibration test results of a modified JetStar airplane using impulsive sine as an excitation waveform are compared with the test results of the same airplane using multiple-input random excitation. The results indicated that the structure was sufficiently excited using the impulsive sine waveform. Comparisons of input force spectrums, mode shape plots, and frequency and damping values for the two methods of excitation are presented.
De Visscher, Alice; Noël, Marie-Pascale; De Smedt, Bert
2016-12-01
Arithmetic facts, in particular multiplication tables, are thought to be stored in long-term memory and to be interference prone. At least two representations underpinning these arithmetic facts have been suggested: a physical representation of the digits and a numerical magnitude representation. We hypothesized that both representations are possible sources of interference that could explain individual differences in multiplication fact performance and/or in strategy use. We investigated the specificity of these interferences on arithmetic fact retrieval and explored the relation between interference and performance on the different arithmetic operations and on general mathematics achievement. Participants were 79 fourth-grade children (M age =9.6 years) who completed a products comparison and a multiplication production task with verbal strategy reports. Performances on a speeded calculation test including the four operations and on a general mathematics achievement test were also collected. Only the interference coming from physical representations was a significant predictor of the performance across multiplications. However, both the magnitude and physical representations were unique predictors of individual differences in multiplication. The frequency of the retrieval strategy across multiplication problems and across individuals was determined only by the physical representation, which therefore is suggested as being responsible for memory storage issues. Interestingly, this impact of physical representation was not observed when predicting performance on subtraction or on general mathematical achievement. In contrast, the impact of the numerical magnitude representation was more general in that it was observed across all arithmetic operations and in general mathematics achievement. Copyright © 2016 Elsevier Inc. All rights reserved.
Color discrimination across four life decades assessed by the Cambridge Colour Test.
Paramei, Galina V
2012-02-01
Color discrimination was estimated using the Cambridge Colour Test (CCT) in 160 normal trichromats of four life decades, 20-59 years of age. For each age cohort, medians and tolerance limits of the CCT parameters are tabulated. Compared across the age cohorts (Kruskal-Wallis test), the Trivector test showed increases in the three vectors, Protan, Deutan, and Tritan, with advancing age; the Ellipses test revealed significant elongation of the major axes of all three ellipses but no changes in either the axis ratio or the angle of the ellipse major axis. Multiple comparisons (Mann-Whitney test) between the cohorts of four age decades (20+,…,50+) revealed initial benign deterioration of color discrimination in the 40+ decade, as an incremental loss of discrimination along the Deutan axis (Trivector test), and in the 50+ decade, as an elongation of the major axes of all three ellipses (Ellipses test). © 2012 Optical Society of America
Liu, Yuewei; Chen, Weihong
2012-02-01
As a nonparametric method, the Kruskal-Wallis test is widely used to compare three or more independent groups when an ordinal or interval level of data is available, especially when the assumptions of analysis of variance (ANOVA) are not met. If the Kruskal-Wallis statistic is statistically significant, Nemenyi test is an alternative method for further pairwise multiple comparisons to locate the source of significance. Unfortunately, most popular statistical packages do not integrate the Nemenyi test, which is not easy to be calculated by hand. We described the theory and applications of the Kruskal-Wallis and Nemenyi tests, and presented a flexible SAS macro to implement the two tests. The SAS macro was demonstrated by two examples from our cohort study in occupational epidemiology. It provides a useful tool for SAS users to test the differences among three or more independent groups using a nonparametric method.
On assessing bioequivalence and interchangeability between generics based on indirect comparisons.
Zheng, Jiayin; Chow, Shein-Chung; Yuan, Mengdie
2017-08-30
As more and more generics become available in the market place, the safety/efficacy concerns may arise as the result of interchangeably use of approved generics. However, bioequivalence assessment for regulatory approval among generics of the innovative drug product is not required. In practice, approved generics are often used interchangeably without any mechanism of safety monitoring. In this article, based on indirect comparisons, we proposed several methods to assessing bioequivalence and interchangeability between generics. The applicability of the methods and the similarity assumptions were discussed, as well as the inappropriateness of directly adopting adjusted indirect comparison to the field of generics' comparison. Besides, some extensions were given to take into consideration the important topics in clinical trials for bioequivalence assessments, for example, multiple comparisons and simultaneously testing bioequivalence among three generics. Extensive simulation studies were conducted to investigate the performances of the proposed methods. The studies of malaria generics and HIV/AIDS generics prequalified by the WHO were used as real examples to demonstrate the use of the methods. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.
Felix, Leonardo Bonato; Miranda de Sá, Antonio Mauricio Ferreira Leite; Infantosi, Antonio Fernando Catelli; Yehia, Hani Camille
2007-03-01
The presence of cerebral evoked responses can be tested by using objective response detectors. They are statistical tests that provide a threshold above which responses can be assumed to have occurred. The detection power depends on the signal-to-noise ratio (SNR) of the response and the amount of data available. However, the correlation within the background noise could also affect the power of such detectors. For a fixed SNR, the detection can only be improved at the expense of using a longer stretch of signal. This can constitute a limitation, for instance, in monitored surgeries. Alternatively, multivariate objective response detection (MORD) could be used. This work applies two MORD techniques (multiple coherence and multiple component synchrony measure) to EEG data collected during intermittent photic stimulation. They were evaluated throughout Monte Carlo simulations, which also allowed verifying that correlation in the background reduces the detection rate. Considering the N EEG derivations as close as possible to the primary visual cortex, if N = 4, 6 or 8, multiple coherence leads to a statistically significant higher detection rate in comparison with multiple component synchrony measure. With the former, the best performance was obtained with six signals (O1, O2, T5, T6, P3 and P4).
Baxter, Melissa; Withey, Sarah; Harrison, Sean; Segeritz, Charis-Patricia; Zhang, Fang; Atkinson-Dell, Rebecca; Rowe, Cliff; Gerrard, Dave T.; Sison-Young, Rowena; Jenkins, Roz; Henry, Joanne; Berry, Andrew A.; Mohamet, Lisa; Best, Marie; Fenwick, Stephen W.; Malik, Hassan; Kitteringham, Neil R.; Goldring, Chris E.; Piper Hanley, Karen; Vallier, Ludovic; Hanley, Neil A.
2015-01-01
Background & Aims Hepatocyte-like cells (HLCs), differentiated from pluripotent stem cells by the use of soluble factors, can model human liver function and toxicity. However, at present HLC maturity and whether any deficit represents a true fetal state or aberrant differentiation is unclear and compounded by comparison to potentially deteriorated adult hepatocytes. Therefore, we generated HLCs from multiple lineages, using two different protocols, for direct comparison with fresh fetal and adult hepatocytes. Methods Protocols were developed for robust differentiation. Multiple transcript, protein and functional analyses compared HLCs to fresh human fetal and adult hepatocytes. Results HLCs were comparable to those of other laboratories by multiple parameters. Transcriptional changes during differentiation mimicked human embryogenesis and showed more similarity to pericentral than periportal hepatocytes. Unbiased proteomics demonstrated greater proximity to liver than 30 other human organs or tissues. However, by comparison to fresh material, HLC maturity was proven by transcript, protein and function to be fetal-like and short of the adult phenotype. The expression of 81% phase 1 enzymes in HLCs was significantly upregulated and half were statistically not different from fetal hepatocytes. HLCs secreted albumin and metabolized testosterone (CYP3A) and dextrorphan (CYP2D6) like fetal hepatocytes. In seven bespoke tests, devised by principal components analysis to distinguish fetal from adult hepatocytes, HLCs from two different source laboratories consistently demonstrated fetal characteristics. Conclusions HLCs from different sources are broadly comparable with unbiased proteomic evidence for faithful differentiation down the liver lineage. This current phenotype mimics human fetal rather than adult hepatocytes. PMID:25457200
Baila-Rueda, Lucía; Lamiquiz-Moneo, Itziar; Jarauta, Estíbaliz; Mateo-Gallego, Rocío; Perez-Calahorra, Sofía; Marco-Benedí, Victoria; Bea, Ana M; Cenarro, Ana; Civeira, Fernando
2018-01-15
Familial hypercholesterolemia (FH) is a genetic disorder that result in abnormally high low-density lipoprotein cholesterol levels, markedly increased risk of coronary heart disease (CHD) and tendon xanthomas (TX). However, the clinical expression is highly variable. TX are present in other metabolic diseases that associate increased sterol concentration. If non-cholesterol sterols are involved in the development of TX in FH has not been analyzed. Clinical and biochemical characteristics, non-cholesterol sterols concentrations and Aquilles tendon thickness were determined in subjects with genetic FH with (n = 63) and without (n = 40) TX. Student-t test o Mann-Whitney test were used accordingly. Categorical variables were compared using a Chi square test. ANOVA and Kruskal-Wallis tests were performed to multiple independent variables comparison. Post hoc adjusted comparisons were performed with Bonferroni correction when applicable. Correlations of parameters in selected groups were calculated applying the non-parametric Spearman correlation procedure. To identify variables associated with Achilles tendon thickness changes, multiple linear regression were applied. Patients with TX presented higher concentrations of non-cholesterol sterols in plasma than patients without xanthomas (P = 0.006 and 0.034, respectively). Furthermore, there was a significant association between 5α-cholestanol, β-sitosterol, desmosterol, 24S-hydroxycholesterol and 27-hydroxycholesterol concentrations and Achilles tendon thickness (p = 0.002, 0.012, 0.020, 0.045 and 0.040, respectively). Our results indicate that non-cholesterol sterol concentrations are associated with the presence of TX. Since cholesterol and non-cholesterol sterols are present in the same lipoproteins, further studies would be needed to elucidate their potential role in the development of TX.
Beiske, Kornelia K; Sand, Trond; Rugland, Eyvind; Stavem, Knut
2017-05-01
Comparison of mean sleep latencies and number of sleep-onset rapid eye movement periods (SOREMPs) between modified multiple sleep latency test (MSLT) performed in the unattended home and in-hospital laboratory setting. A randomized crossover single-blinded design. Thirty-four subjects referred to MSLT for suspected hypersomnia or narcolepsy were included. Participants were randomized to perform modified MSLT in the unattended home or in the hospital first. Scores in the two settings were compared using Wilcoxon signed-rank test or exact McNemar test. Agreement between home and hospital categorized mean sleep latency and number of SOREMPs was assessed using simple kappa (κ) and proportion agreement. Agreement between home and hospital mean sleep latency was assessed using a Bland-Altman plot and an intraclass correlation coefficient. There was no difference between home and hospital assessment of mean sleep latency (P = 0.86). Two or more SOREMPs were found more frequently on modified MSLTs performed at home compared with those at the hospital (7 and 2, respectively; P = 0.025). Agreement was moderate for categorized sleep latency (κ = 0.53) and fair for categorized SOREMPs (κ = 0.39) in the 2 settings. Analysis of mean sleep latency using intraclass correlation coefficient showed a very good agreement between the two settings. Group mean sleep latency for home modified MSLTs seems to be reliable compared with that for the attended sleep-laboratory setting. Higher rate of SOREMP in the unattended home suggests that napping in a familiar environment facilitates the transition into REM sleep. Further studies are needed to assess the normal limit, sensitivity, and specificity for SOREMP at home before the clinical utility of home-based napping can be determined.
Double-multiple streamtube model for Darrieus in turbines
NASA Technical Reports Server (NTRS)
Paraschivoiu, I.
1981-01-01
An analytical model is proposed for calculating the rotor performance and aerodynamic blade forces for Darrieus wind turbines with curved blades. The method of analysis uses a multiple-streamtube model, divided into two parts: one modeling the upstream half-cycle of the rotor and the other, the downstream half-cycle. The upwind and downwind components of the induced velocities at each level of the rotor were obtained using the principle of two actuator disks in tandem. Variation of the induced velocities in the two parts of the rotor produces larger forces in the upstream zone and smaller forces in the downstream zone. Comparisons of the overall rotor performance with previous methods and field test data show the important improvement obtained with the present model. The calculations were made using the computer code CARDAA developed at IREQ. The double-multiple streamtube model presented has two major advantages: it requires a much shorter computer time than the three-dimensional vortex model and is more accurate than multiple-streamtube model in predicting the aerodynamic blade loads.
Wurdeman, Shane R; Huisinga, Jessie M; Filipi, Mary; Stergiou, Nicholas
2011-02-01
Multiple sclerosis is a progressive neurological disease that results in a high incident of gait disturbance. Exploring the frequency content of the ground reaction forces generated during walking may provide additional insights to gait in patients with multiple sclerosis that could lead to specific tools for differential diagnosis. The purpose of this study was to investigate differences in the frequency content of these forces in an effort to contribute to improved clinical management of this disease. Eighteen patients and eighteen healthy controls walked across a 10 meter long walkway. The anterior-posterior and vertical ground reaction forces generated during the stance phase of gait were evaluated in the frequency domain using fast Fourier transformation. T-tests were utilized for comparison of median frequency, the 99.5% frequency, and the frequency bandwidth between patients and healthy controls and also for comparisons between patients with mild and moderate severity. Patients with multiple sclerosis had significantly lower 99.5% frequency (P=0.006) and median frequency (P<0.001) in the vertical ground reaction force. No differences were found in the anterior-posterior reaction force frequency content. There were no differences between patients with mild and moderate severity. The lower frequency content suggests lesser vertical oscillation of the center of gravity. Lack of differences between severities may suggest presence of differences prior to currently established diagnosis timelines. Analysis of the frequency content may potentially serve to provide earlier diagnostic assessment of this debilitating disease. Copyright © 2010 Elsevier Ltd. All rights reserved.
Pizza, Fabio; Contardi, Sara; Mondini, Susanna; Trentin, Lino; Cirignotta, Fabio
2009-01-01
Study Objectives: To test the reliability of a driving-simulation test for the objective measurement of daytime alertness compared with the Multiple Sleep Latency Test (MSLT) and with the Maintenance of Wakefulness Test (MWT), and to test the ability to drive safely, in comparison with on-road history, in the clinical setting of untreated severe obstructive sleep apnea. Design: N/A. Setting: Sleep laboratory. Patients or Participants: Twenty-four patients with severe obstructive sleep apnea and reported daytime sleepiness varying in severity (as measured by the Epworth Sleepiness Scale). Interventions: N/A. Measurements and Results: Patients underwent MSLT and MWT coupled with 4 sessions of driving-simulation test on 2 different days randomly distributed 1 week apart. Simulated-driving performance (in terms of lane-position variability and crash occurrence) was correlated with sleep latency on the MSLT and more significantly on the MWT, showing a predictive validity toward the detection of sleepy versus alert patients with obstructive sleep apnea. In addition, patients reporting excessive daytime sleepiness or a history of car crashes showed poorer performances on the driving simulator. Conclusions: A simulated driving test is a suitable tool for objective measurement of daytime alertness in patients with obstructive sleep apnea. Further studies are needed to clarify the association between simulated-driving performance and on-road crash risk of patients with sleep disordered breathing. Citation: Pizza F; Contardi S; Mondini S; Trentin L; Cirignotta F. Daytime sleepiness and driving performance in patients with obstructive sleep apnea: comparison of the MSLT, the MWT, and a simulated driving task. SLEEP 2009;32(3):382-391. PMID:19294958
NASA Technical Reports Server (NTRS)
Buttery, Michael
2010-01-01
We present the findings of the test program performed by The European Space Tribology Laboratory (ESTL) to evaluate the performance (friction and lifetime) of a number of space lubricants under vacuum using a Spiral Orbit Tribometer (SOT). Focus was given to a comparison of various popular space oils, a comparison study between the old and new MAPLUB grease formulations, and the performance of commonly used solid lubricants under various conditions. Tests demonstrated that the lifetimes of hydrocarbon NYE oils 2001 & 2001A outperformed those of the perfluroropolyalkylether (PFPE) oils Fomblin Z25 & Z60, though these pairs displayed similar behavior. This relationship was also generally seen for greases; with the lifetimes of the multiple alkylated cyclopentane (MAC)-based greases being extended in comparison to the PFPE-based greases. Testing on greases also demonstrated similar performance between the old (-a) and new (-b) formulations when considering PFPE-based MAPLUB greases, and indeed for all tested PFPE-based non-MAPLUB greases, but significantly shorter lifetimes for the new formulations when considering MAC-based MAPLUB greases. MAPLUB MAC greases containing molybdenum disulphide (MoS2) thickener were also found to display reduced lifetimes. For solid lubricants, lead displayed significantly extended lifetimes over MoS2, speculated to be caused by redistribution of lead from the ball onto all contact surfaces during the test. Friction coefficients were seen to be some 2.5x higher for lead than for MoS2 under similar conditions, a result that corresponds well with conventional bearing tests. The work described was performed under contract for the European Space Agency as part of the Tribology Applications Program, with all funding for testing and apparatus provided by European Space Agency (ESA).
NASA Astrophysics Data System (ADS)
Pan, J.; Durand, M. T.; Sandells, M. J.; Lemmetyinen, J.; Kim, E. J.
2013-12-01
Application of passive microwave (PM) brightness temperature for snow water equivalent retrieval requires deep understanding of snow emission models, not only for their performance to reproduce in-situ PM observations, but also for their theoretical differences to approximate radiative transfer theory. In this paper, differences between the multiple-layer HUT (or TKK) model and the Microwave Emission Model of Layered Snowpacks (MEMLS) were listed, and the two models were compared with snow ground-based PM observations at Streamboat Springs, Colorado, USA; Churchill, Canada; and Sodankyla, Finland. The two models were chosen for their multiple-layer schemes are close to actual layer-by-layer snow measurements. Both the two models are semi-empirical models; whereas the HUT model uses the mean snow grain size, MEMLS uses the correlation length to relate the snow microstructure with the scattering coefficients. The two parameters are related according to previous studies. The Specific Surface Area (SSA) was measured at three test sites to derive the correlation length, while the mean snow grain sizes was available at Stream Springs and Sodankyla. It was shown that with different apparent forms of radiative transfer equations, the different parts of the two models have one-to-one correspondence however, and intermediate parameters are comparable. Regarding the multiple-layer structure of the models, it was found that the HUT model considers the internal reflectivity of each snow layer to be zero. The two-flux radiative transfer equations of the two models were compared, and the correspondence of the semi-empirical parameter q in the HUT model was found in the MEMLS. The effect of consideration of transverse radiation scattered into the direction under consideration via the six-flux approximation in MEMLS is compared. Based on model comparisons, we analyzed the differences of TB predictions at the three test sites.
Functional equivalency inferred from "authoritative sources" in networks of homologous proteins.
Natarajan, Shreedhar; Jakobsson, Eric
2009-06-12
A one-on-one mapping of protein functionality across different species is a critical component of comparative analysis. This paper presents a heuristic algorithm for discovering the Most Likely Functional Counterparts (MoLFunCs) of a protein, based on simple concepts from network theory. A key feature of our algorithm is utilization of the user's knowledge to assign high confidence to selected functional identification. We show use of the algorithm to retrieve functional equivalents for 7 membrane proteins, from an exploration of almost 40 genomes form multiple online resources. We verify the functional equivalency of our dataset through a series of tests that include sequence, structure and function comparisons. Comparison is made to the OMA methodology, which also identifies one-on-one mapping between proteins from different species. Based on that comparison, we believe that incorporation of user's knowledge as a key aspect of the technique adds value to purely statistical formal methods.
Wu, Wenting; Bot, Brian; Hu, Yan; Geyer, Susan M; Sargent, Daniel J
2013-07-01
Sargent and Goldberg [1] proposed a randomized phase II flexible screening design (SG design) which took multiple characteristics of candidate regimens into consideration in selecting a regimen for further phase III testing. In this paper, we extend the SG design by including provisions for an interim analysis and/or a comparison to a historical control. By including a comparison with a historical control, a modified SG design not only identifies a more promising treatment but also assures that the regimen has a clinically meaningful level of efficacy as compared to a historical control. By including an interim analysis, a modified SG design could reduce the number of patients exposed to inferior treatment regimens. When compared to the original SG design, the modified designs increase the sample size moderately, but expand the utility of the flexible screening design substantially. Copyright © 2013 Elsevier Inc. All rights reserved.
Functional Equivalency Inferred from “Authoritative Sources” in Networks of Homologous Proteins
Natarajan, Shreedhar; Jakobsson, Eric
2009-01-01
A one-on-one mapping of protein functionality across different species is a critical component of comparative analysis. This paper presents a heuristic algorithm for discovering the Most Likely Functional Counterparts (MoLFunCs) of a protein, based on simple concepts from network theory. A key feature of our algorithm is utilization of the user's knowledge to assign high confidence to selected functional identification. We show use of the algorithm to retrieve functional equivalents for 7 membrane proteins, from an exploration of almost 40 genomes form multiple online resources. We verify the functional equivalency of our dataset through a series of tests that include sequence, structure and function comparisons. Comparison is made to the OMA methodology, which also identifies one-on-one mapping between proteins from different species. Based on that comparison, we believe that incorporation of user's knowledge as a key aspect of the technique adds value to purely statistical formal methods. PMID:19521530
Lexical retrieval in discourse: An early indicator of Alzheimer's dementia
Pekkala, Seija; Wiener, Debra; Himali, Jayandra J.J.; Beiser, Alexa S.; Obler, Loraine K.; Liu, Yulin; McKee, Ann; Auerbach, Sanford; Seshadri, Sudha; Wolf, Philip A.; Au, Rhoda
2014-01-01
We examined the progression of lexical-retrieval deficits in individuals with neuropathologically determined Alzheimer's disease (AD; n = 23) and a comparison group without criteria for AD (n = 24) to determine whether linguistic changes were a significant marker of the disease. Our participants underwent multiple administrations of a neuropsychological battery, with initial administration occurring on average 16 years prior to death. The battery included the Boston Naming Test (BNT), a letter fluency task (FAS), and written description of the Cookie Theft Picture (CTP). Repeated measures analysis revealed that the AD-group showed progressively greater decline in FAS and CTP lexical performance than the comparison group. Cross-sectional time-specific group comparisons indicated that the CTP differentiated performance between the two groups at 7–9 years prior to death and FAS and BNT only at 2–4 years. These results suggest that lexical-retrieval deficits in written discourse serve as an early indicator of AD. PMID:23985011
Lexical retrieval in discourse: an early indicator of Alzheimer's dementia.
Pekkala, Seija; Wiener, Debra; Himali, Jayandra J; Beiser, Alexa S; Obler, Loraine K; Liu, Yulin; McKee, Ann; Auerbach, Sanford; Seshadri, Sudha; Wolf, Philip A; Au, Rhoda
2013-12-01
We examined the progression of lexical-retrieval deficits in individuals with neuropathologically determined Alzheimer's disease (AD; n = 23) and a comparison group without criteria for AD (n = 24) to determine whether linguistic changes were a significant marker of the disease. Our participants underwent multiple administrations of a neuropsychological battery, with initial administration occurring on average 16 years prior to death. The battery included the Boston Naming Test (BNT), a letter fluency task (FAS) and written description of the Cookie Theft Picture (CTP). Repeated measures analysis revealed that the AD-group showed progressively greater decline in FAS and CTP lexical performance than the comparison group. Cross-sectional time-specific group comparisons indicated that the CTP differentiated performance between the two groups at 7-9 years prior to death and FAS and BNT only at 2-4 years. These results suggest that lexical-retrieval deficits in written discourse serve as an early indicator of AD.
Three-dimensional geostatistical inversion of flowmeter and pumping test data.
Li, Wei; Englert, Andreas; Cirpka, Olaf A; Vereecken, Harry
2008-01-01
We jointly invert field data of flowmeter and multiple pumping tests in fully screened wells to estimate hydraulic conductivity using a geostatistical method. We use the steady-state drawdowns of pumping tests and the discharge profiles of flowmeter tests as our data in the inference. The discharge profiles need not be converted to absolute hydraulic conductivities. Consequently, we do not need measurements of depth-averaged hydraulic conductivity at well locations. The flowmeter profiles contain information about relative vertical distributions of hydraulic conductivity, while drawdown measurements of pumping tests provide information about horizontal fluctuation of the depth-averaged hydraulic conductivity. We apply the method to data obtained at the Krauthausen test site of the Forschungszentrum Jülich, Germany. The resulting estimate of our joint three-dimensional (3D) geostatistical inversion shows an improved 3D structure in comparison to the inversion of pumping test data only.
Treatment of the Cornea Using Transcytotic Delivery into the Tear Film
2015-12-01
early April 2013; however, we continue to produce additional material as required (Fig. 4). In milestone 3 we initiated in vivo evaluation of...SI, the minimum and maximum values are 12.4 and 34.4. 8 Aim 2) characterize Lacritin-ELP fusion proteins and evaluate as therapeutic agents...0.0001). Data were analyzed by a two-way ANOVA followed by Tukey’s multiple comparisons test (n=9). 10 Having evaluated the lacritin-ELP fusion in
AGARWAL, SANDEEP K.; GOURH, PRAVITT; SHETE, SANJAY; PAZ, GENE; DIVECHA, DIPAL; REVEILLE, JOHN D.; ASSASSI, SHERVIN; TAN, FILEMON K.; MAYES, MAUREEN D.; ARNETT, FRANK C.
2010-01-01
Objective IL23R has been identified as a susceptibility gene for development of multiple autoimmune diseases. We investigated the possible association of IL23R with systemic sclerosis (SSc), an autoimmune disease that leads to the development of cutaneous and visceral fibrosis. Methods We tested 9 single-nucleotide polymorphisms (SNP) in IL23R for association with SSc in a cohort of 1402 SSc cases and 1038 controls. IL23R SNP tested were previously identified as SNP showing associations with inflammatory bowel disease. Results Case-control comparisons revealed no statistically significant differences between patients and healthy controls with any of the IL23R polymorphisms. Analyses of subsets of SSc patients showed that rs11209026 (Arg381Gln variant) was associated with anti-topoisomerase I antibody (ATA)-positive SSc (p = 0.001)) and rs11465804 SNP was associated with diffuse and ATA-positive SSc (p = 0.0001, p = 0.0026, respectively). These associations remained significant after accounting for multiple comparisons using the false discovery rate method. Wild-type genotype at both rs11209026 and rs11465804 showed significant protection against the presence of pulmonary hypertension (PHT). (p = 3×10−5, p = 1×10−5, respectively). Conclusion Polymorphisms in IL23R are associated with susceptibility to ATA-positive SSc and protective against development of PHT in patients with SSc. PMID:19918037
Bristow, P; Tivers, M; Packer, R; Brockman, D; Ortiz, V; Newson, K; Lipscomb, V
2017-08-01
To report the long-term bile acid stimulation test results for dogs that have undergone complete suture ligation of a single congenital extrahepatic portosystemic shunt. Data were collected from the hospital records of all dogs that had undergone a complete suture ligation of a single congenital extrahepatic portosystemic shunt. Owners were invited to return to the referral centre or their local veterinarian for repeat serum bile acid measurement. Dogs diagnosed with idiopathic epilepsy and undergoing bile acid stimulation tests were used as a comparison population. Fifty-one study dogs were included, with a mean follow-up time of 62 months. 48 dogs had no evidence of multiple acquired shunts and a significant reduction in the pre- and post-prandial serum bile acid concentrations at long-term follow-up compared with pre-operative measurements. Pre- and post-prandial serum bile acids were statistically significantly greater for dogs that had undergone a full ligation (with no evidence of multiple acquired shunts) at all time points compared to the control dogs (P<0·001 for all comparisons). The results suggest that in dogs treated with complete suture ligation mild increases in serum bile acids are not clinically relevant if there are no physical examination abnormalities, a normal body condition score and no relapse in clinical signs. © 2017 British Small Animal Veterinary Association.
Methods of analysis speech rate: a pilot study.
Costa, Luanna Maria Oliveira; Martins-Reis, Vanessa de Oliveira; Celeste, Letícia Côrrea
2016-01-01
To describe the performance of fluent adults in different measures of speech rate. The study included 24 fluent adults, of both genders, speakers of Brazilian Portuguese, who were born and still living in the metropolitan region of Belo Horizonte, state of Minas Gerais, aged between 18 and 59 years. Participants were grouped by age: G1 (18-29 years), G2 (30-39 years), G3 (40-49 years), and G4 (50-59 years). The speech samples were obtained following the methodology of the Speech Fluency Assessment Protocol. In addition to the measures of speech rate proposed by the protocol (speech rate in words and syllables per minute), the rate of speech into phonemes per second and the articulation rate with and without the disfluencies were calculated. We used the nonparametric Friedman test and the Wilcoxon test for multiple comparisons. Groups were compared using the nonparametric Kruskal Wallis. The significance level was of 5%. There were significant differences between measures of speech rate involving syllables. The multiple comparisons showed that all the three measures were different. There was no effect of age for the studied measures. These findings corroborate previous studies. The inclusion of temporal acoustic measures such as speech rate in phonemes per second and articulation rates with and without disfluencies can be a complementary approach in the evaluation of speech rate.
Discerning Trends in Performance Across Multiple Events
NASA Technical Reports Server (NTRS)
Slater, Simon; Hiltz, Mike; Rice, Craig
2006-01-01
Mass Data is a computer program that enables rapid, easy discernment of trends in performance data across multiple flights and ground tests. The program can perform Fourier analysis and other functions for the purposes of frequency analysis and trending of all variables. These functions facilitate identification of past use of diagnosed systems and of anomalies in such systems, and enable rapid assessment of related current problems. Many variables, for computation of which it is usually necessary to perform extensive manual manipulation of raw downlist data, are automatically computed and made available to all users, regularly eliminating the need for what would otherwise be an extensive amount of engineering analysis. Data from flight, ground test, and simulation are preprocessed and stored in one central location for instantaneous access and comparison for diagnostic and trending purposes. Rules are created so that an event log is created for every flight, making it easy to locate information on similar maneuvers across many flights. The same rules can be created for test sets and simulations, and are searchable, so that information on like events is easily accessible.
A High Performance Impedance-based Platform for Evaporation Rate Detection.
Chou, Wei-Lung; Lee, Pee-Yew; Chen, Cheng-You; Lin, Yu-Hsin; Lin, Yung-Sheng
2016-10-17
This paper describes the method of a novel impedance-based platform for the detection of the evaporation rate. The model compound hyaluronic acid was employed here for demonstration purposes. Multiple evaporation tests on the model compound as a humectant with various concentrations in solutions were conducted for comparison purposes. A conventional weight loss approach is known as the most straightforward, but time-consuming, measurement technique for evaporation rate detection. Yet, a clear disadvantage is that a large volume of sample is required and multiple sample tests cannot be conducted at the same time. For the first time in literature, an electrical impedance sensing chip is successfully applied to a real-time evaporation investigation in a time sharing, continuous and automatic manner. Moreover, as little as 0.5 ml of test samples is required in this impedance-based apparatus, and a large impedance variation is demonstrated among various dilute solutions. The proposed high-sensitivity and fast-response impedance sensing system is found to outperform a conventional weight loss approach in terms of evaporation rate detection.
Dutta, Sarmistha; Das, Swarnamoni
2010-01-01
Introduction: The aim is to study the anti-inflammatory effect of the ethanolic extract of the leaves of Psidium guajava(PGE) on experimental animal models. Materials and Methods: Fresh leaves were collected, air-dried, powdered, and percolated in 95% ethanol. Acute toxicity test was done according to OECD guidelines. Four groups of animals of either sex, weighing 150–200g of the species Rattus norvegicus were taken for the study (n = 6). Group A was taken as control (3% gum acacia in 10 mL/kg body weight), Group B as test group (PGE 250 mg/kg body weight), Group C as test group (PGE 500 mg/kg body weight), and Group D as standard (Aspirin 100 mg/kg body weight). The animals were studied for acute inflammation by Carrageenan-induced rat paw edema, subacute inflammation by Granuloma pouch method, and chronic inflammation by Freund’s adjuvant-induced arthritis method. Statistical analysis was done by one-way analysis of variance followed by multiple comparison tests. Results: In acute inflammation, there was significant inhibition of paw edema in Groups B, C, and D in comparison with Group A (P < 0.05). In subacute inflammation, there was significant inhibition of exudate formation in Groups B, C, and D in comparison to Group A (P < 0.05). In chronic inflammation, there was significant inhibition of paw edema and inhibition of weight reduction in Groups B, C, and D compared with Group A. Downregulation of arthritis index was also significant in Groups B, C, and D in comparison with Group A (P < 0.05). Conclusion: The ethanolic extract of PGE has significant anti-inflammatory activity. PMID:21589759
NASA Technical Reports Server (NTRS)
Houtas, Franzeska; Teets, Edward H., Jr.
2010-01-01
A comparison study by the National Aeronautics and Space Administration Dryden Flight Research Center, Edwards, CA and the Naval Post Graduate School Center for Interdisciplinary Remotely-Piloted Aircraft Studies, Marina, CA was conducted to show the advantages of an airborne wind profiling lidar system in reducing drift uncertainty along a reentry vehicle descent trajectory. This effort was in support of the once planned Orion Crew Exploration Vehicle ground landing. A Twin Otter Doppler Wind Lidar was flown on multiple flights along the approximate ground track of an ascending weather balloons launched from the Marina Municipal Airport. The airborne lidar used was a 5-milli-Joules, 2-micron infrared laser with a 10-centimeter telescope and a two-axis scanner. Each lidar wind profile contains data for an altitude range between the surface and flight altitude of 2,700 meters, processed on board every 20 seconds. In comparison, a typical weather balloon would traverse that same altitude range with a similar data set available in approximately 15-20 minutes. These tests were conducted on November 15 & 16, 2007. Results comparing the balloon and a 10 minute multiple lidar profile averages show a best case absolute difference of 0.18 m/s (0.35 knots) in speed and 1 degree in direction during light and variable (less than 5 knots, without constant direction) wind conditions. These limited test results indicated a standard deviation wind velocity and direction differences of 0.71 m/s (1.3 knots) and 7.17 degrees for 1800Z, and 0.70 m/s (1.3 knots) and 6.79 degrees, outside of cloud layer.
NASA Technical Reports Server (NTRS)
Kurtz, R. L.; Liu, H. K.
1974-01-01
When a hologram storing more than one wave is illuminated with coherent light, the reconstructed wave fronts interfere with each other or with any other phase-related wave front derived from the illuminating source. This multiple wave front comparison is called holographic interferometry, and its application is called holographic nondestructive testing (HNDT). The theoretical aspects of HNDT techniques and the sensitivity of the holographic system to the geometrical placement of the optical components are briefly discussed. A unique HNDT system which is mobile and possesses variable sensitivity to stress amplitude is discribed, the experimental evidence of the application of this system to the testing of the hidden debonds in a ceramic-epoxy-fiberglass structure used for sample testing of the radome of the Pershing missile system is presented.
Joshi, Nabin R; Ly, Emma; Viswanathan, Suresh
2017-08-01
To assess the effect of age and test-retest reliability of the intensity response function of the full-field photopic negative response (PhNR) in normal healthy human subjects. Full-field electroretinograms (ERGs) were recorded from one eye of 45 subjects, and 39 of these subjects were tested on two separate days with a Diagnosys Espion System (Lowell, MA, USA). The visual stimuli consisted of brief (<5 ms) red flashes ranging from 0.00625 to 6.4 phot cd.s/m 2 , delivered on a constant 7 cd/m 2 blue background. PhNR amplitudes were measured at its trough from baseline (BT) and from the preceding b-wave peak (PT), and b-wave amplitude was measured at its peak from the preceding a-wave trough or baseline if the a-wave was not present. The intensity response data of all three ERG measures were fitted with a generalized Naka-Rushton function to derive the saturated amplitude (V max ), semisaturation constant (K) and slope (n) parameters. Effect of age on the fit parameters was assessed with linear regression, and test-retest reliability was assessed with the Wilcoxon signed-rank test and Bland-Altman analysis. Holm's correction was applied to account for multiple comparisons. V max of BT was significantly smaller than that of PT and b-wave, and the V max of PT and b-wave was not significantly different from each other. The slope parameter n was smallest for BT and the largest for b-wave and the difference between the slopes of all three measures were statistically significant. Small differences observed in the mean values of K for the different measures did not reach statistical significance. The Wilcoxon signed-rank test indicated no significant differences between the two test visits for any of the Naka-Rushton parameters for the three ERG measures, and the Bland-Altman plots indicated that the mean difference between test and retest measurements of the different fit parameters was close to zero and within 6% of the average of the test and retest values of the respective parameters for all three ERG measurements, indicating minimal bias. While the coefficient of reliability (COR, defined as 1.96 times the standard deviation of the test and retest difference) of each fit parameter was more or less comparable across the three ERG measurements, the %COR (COR normalized to the mean test and retest measures) was generally larger for BT compared to both PT and b-wave for each fit parameter. The Naka-Rushton fit parameters did not show statistically significant changes with age for any of the ERG measures when corrections were applied for multiple comparisons. However, the V max of BT demonstrated a weak correlation with age prior to correction for multiple comparisons, and the effect of age on this parameter showed greater significance when the measure was expressed as a ratio of the V max of b-wave from the same subject. V max of the BT amplitude measure of PhNR at the best was weakly correlated with age. None of the other parameters of the Naka-Rushton fit to the intensity response data of either the PhNR or the b-wave showed any systematic changes with age. The test-retest reliability of the fit parameters for PhNR BT amplitude measurements appears to be lower than those of the PhNR PT and b-wave amplitude measurements.
Statistics in biomedical laboratory and clinical science: applications, issues and pitfalls.
Ludbrook, John
2008-01-01
This review is directed at biomedical scientists who want to gain a better understanding of statistics: what tests to use, when, and why. In my view, even during the planning stage of a study it is very important to seek the advice of a qualified biostatistician. When designing and analyzing a study, it is important to construct and test global hypotheses, rather than to make multiple tests on the data. If the latter cannot be avoided, it is essential to control the risk of making false-positive inferences by applying multiple comparison procedures. For comparing two means or two proportions, it is best to use exact permutation tests rather then the better known, classical, ones. For comparing many means, analysis of variance, often of a complex type, is the most powerful approach. The correlation coefficient should never be used to compare the performances of two methods of measurement, or two measures, because it does not detect bias. Instead the Altman-Bland method of differences or least-products linear regression analysis should be preferred. Finally, the educational value to investigators of interaction with a biostatistician, before, during and after a study, cannot be overemphasized. (c) 2007 S. Karger AG, Basel.
Yanagisawa, Yukio; Matsuo, Yoshimi; Shuntoh, Hisato; Horiuchi, Noriaki
2014-01-01
[Purpose] The purpose of this study was to elucidate the effect of expiratory resistive loading on orbicularis oris muscle activity. [Subjects] Subjects were 23 healthy individuals (11 males, mean age 25.5±4.3 years; 12 females, mean age 25.0±3.0 years). [Methods] Surface electromyography was performed to measure the activity of the orbicularis oris muscle during maximum lip closure and resistive loading at different expiratory pressures. Measurement was performed at 10%, 30%, 50%, and 100% of maximum expiratory pressure (MEP) for all subjects. The t-test was used to compare muscle activity between maximum lip closure and 100% MEP, and analysis of variance followed by multiple comparisons was used to compare the muscle activities observed at different expiratory pressures. [Results] No significant difference in muscle activity was observed between maximum lip closure and 100% MEP. Analysis of variance with multiple comparisons revealed significant differences among the different expiratory pressures. [Conclusion] Orbicularis oris muscle activity increased with increasing expiratory resistive loading. PMID:24648644
Joseph, Agnel Praveen; Srinivasan, Narayanaswamy; de Brevern, Alexandre G
2012-09-01
Comparison of multiple protein structures has a broad range of applications in the analysis of protein structure, function and evolution. Multiple structure alignment tools (MSTAs) are necessary to obtain a simultaneous comparison of a family of related folds. In this study, we have developed a method for multiple structure comparison largely based on sequence alignment techniques. A widely used Structural Alphabet named Protein Blocks (PBs) was used to transform the information on 3D protein backbone conformation as a 1D sequence string. A progressive alignment strategy similar to CLUSTALW was adopted for multiple PB sequence alignment (mulPBA). Highly similar stretches identified by the pairwise alignments are given higher weights during the alignment. The residue equivalences from PB based alignments are used to obtain a three dimensional fit of the structures followed by an iterative refinement of the structural superposition. Systematic comparisons using benchmark datasets of MSTAs underlines that the alignment quality is better than MULTIPROT, MUSTANG and the alignments in HOMSTRAD, in more than 85% of the cases. Comparison with other rigid-body and flexible MSTAs also indicate that mulPBA alignments are superior to most of the rigid-body MSTAs and highly comparable to the flexible alignment methods. Copyright © 2012 Elsevier Masson SAS. All rights reserved.
Influence of pneumococcal conjugate vaccines on acute otitis media in Japan.
Sasaki, Atsushi; Kunimoto, Masaru; Takeno, Sachio; Sumiya, Takahiro; Ishino, Takashi; Sugino, Hirotoshi; Hirakawa, Katsuhiro
2017-11-01
This study investigated: (i) changes in the incidence of acute otitis media (AOM) following introduction of public funding for free inoculation with 7- and 13-valent pneumococcal conjugate vaccines (PCV7 and PCV13, respectively) and (ii) changes in the rate of myringotomies for AOM (MyfA) in children 1year following the publication of the first edition of the clinical practice guidelines for the diagnosis and management of AOM in children in Japan. PCV7 was launched on the Japanese market in 2010 and gained public funding in 2011. PCV7 was replaced with PCV13 in November 2013. Using the Japan Medical Data Center Claims Database, an 11-year study conducted between January 2005 and December 2015 investigated the decline in the incidence of visits to medical institutions (VtMI) due to all-cause AOM in children <15years. The rate of MyfA from January 2007 to December 2015was also investigated and changes before and after introduction of public funding for PCV7 (pfPCV7) and PCV13 (pfPCV13) for children were examined. Statistical data for the age group between 10 years and <15years served as the control. An analysis was conducted to examine changes for each age group, from infants that had received PCVs to children <5years. Statistical analysis was performed using the chi-square test and Ryan's multiple comparison tests. Ryan's multiple comparison tests were applied at a 5% level of significance. Due to significant changes in the guidelines on the indications for myringotomy introduced in 2013, statistical analysis of the rate of MyfA was limited to the pre- and post-PCV7 period. After introduction of pfPCV7 and pfPCV13, no significant suppression of the incidence of VtMI was observed in any age group. There was a gradual decline in the rate of MyfA after 2011. Compared to the control group, significant differences in all age groups from infants to children <5years were observed (p<0.009, chi-square test). Within 2 years after the introduction of PCV7, a significant decline in the rate of MyfA was observed in 1- and 5-year-olds using Ryan's multiple comparison tests at a 5% level of significance. The preventative effect of PCVs on AOM was not established in this study. There was, however, a significant decline in the rate of MyfA among 1- and 5-year-olds. Taking into consideration past studies, PCV7 may play a role in preventing the aggravation of AOM in 1-year-olds. When evaluating the effectiveness of PCVs, measures to evaluate severity may be as important as evaluating disease prevention. Copyright © 2017 Elsevier B.V. All rights reserved.
Design and Testing of CPAS Main Deployment Bag Energy Modulator
NASA Technical Reports Server (NTRS)
Mollmann, Catherine
2017-01-01
During the developmental testing program for CPAS (Capsule Parachute Assembly System), the parachute system for the NASA Orion Crew Module, simulation revealed that high loads may be experienced by the pilot risers during the most devere deployment conditions. As the role of the pilot parachutes is to deploy the main parachutes, these high loads introduced the possibility of main deployment failure. In order to mitigate these high loads, a set of energy modulators was incorporated between the pilot riser and the main deployment bag. An extensive developmental program was implemented to ensure the adequacy of these energy modulators. After initial design comparisons, the energy modulator design was validated through slow-speed joint tests as well as through high-speed bungee tests. This paper documents the design, development, and results of multiple tests completed on the final design.
Incremental Aerodynamic Coefficient Database for the USA2
NASA Technical Reports Server (NTRS)
Richardson, Annie Catherine
2016-01-01
In March through May of 2016, a wind tunnel test was conducted by the Aerosciences Branch (EV33) to visually study the unsteady aerodynamic behavior over multiple transition geometries for the Universal Stage Adapter 2 (USA2) in the MSFC Aerodynamic Research Facility's Trisonic Wind Tunnel (TWT). The purpose of the test was to make a qualitative comparison of the transonic flow field in order to provide a recommended minimum transition radius for manufacturing. Additionally, 6 Degree of Freedom force and moment data for each configuration tested was acquired in order to determine the geometric effects on the longitudinal aerodynamic coefficients (Normal Force, Axial Force, and Pitching Moment). In order to make a quantitative comparison of the aerodynamic effects of the USA2 transition geometry, the aerodynamic coefficient data collected during the test was parsed and incorporated into a database for each USA2 configuration tested. An incremental aerodynamic coefficient database was then developed using the generated databases for each USA2 geometry as a function of Mach number and angle of attack. The final USA2 coefficient increments will be applied to the aerodynamic coefficients of the baseline geometry to adjust the Space Launch System (SLS) integrated launch vehicle force and moment database based on the transition geometry of the USA2.
A Novel Wireless Wearable Volatile Organic Compound (VOC) Monitoring Device with Disposable Sensors.
Deng, Yue; Chen, Cheng; Xian, Xiaojun; Tsow, Francis; Verma, Gaurav; McConnell, Rob; Fruin, Scott; Tao, Nongjian; Forzani, Erica S
2016-12-03
A novel portable wireless volatile organic compound (VOC) monitoring device with disposable sensors is presented. The device is miniaturized, light, easy-to-use, and cost-effective. Different field tests have been carried out to identify the operational, analytical, and functional performance of the device and its sensors. The device was compared to a commercial photo-ionization detector, gas chromatography-mass spectrometry, and carbon monoxide detector. In addition, environmental operational conditions, such as barometric change, temperature change and wind conditions were also tested to evaluate the device performance. The multiple comparisons and tests indicate that the proposed VOC device is adequate to characterize personal exposure in many real-world scenarios and is applicable for personal daily use.
A Novel Wireless Wearable Volatile Organic Compound (VOC) Monitoring Device with Disposable Sensors
Deng, Yue; Chen, Cheng; Xian, Xiaojun; Tsow, Francis; Verma, Gaurav; McConnell, Rob; Fruin, Scott; Tao, Nongjian; Forzani, Erica S.
2016-01-01
A novel portable wireless volatile organic compound (VOC) monitoring device with disposable sensors is presented. The device is miniaturized, light, easy-to-use, and cost-effective. Different field tests have been carried out to identify the operational, analytical, and functional performance of the device and its sensors. The device was compared to a commercial photo-ionization detector, gas chromatography-mass spectrometry, and carbon monoxide detector. In addition, environmental operational conditions, such as barometric change, temperature change and wind conditions were also tested to evaluate the device performance. The multiple comparisons and tests indicate that the proposed VOC device is adequate to characterize personal exposure in many real-world scenarios and is applicable for personal daily use. PMID:27918484
A novel PMT test system based on waveform sampling
NASA Astrophysics Data System (ADS)
Yin, S.; Ma, L.; Ning, Z.; Qian, S.; Wang, Y.; Jiang, X.; Wang, Z.; Yu, B.; Gao, F.; Zhu, Y.; Wang, Z.
2018-01-01
Comparing with the traditional test system based on a QDC and TDC and scaler, a test system based on waveform sampling is constructed for signal sampling of the 8"R5912 and the 20"R12860 Hamamatsu PMT in different energy states from single to multiple photoelectrons. In order to achieve high throughput and to reduce the dead time in data processing, the data acquisition software based on LabVIEW is developed and runs with a parallel mechanism. The analysis algorithm is realized in LabVIEW and the spectra of charge, amplitude, signal width and rising time are analyzed offline. The results from Charge-to-Digital Converter, Time-to-Digital Converter and waveform sampling are discussed in detailed comparison.
Prolonged 500 C Operation of 100+ Transistor Silicon Carbide Integrated Circuits
NASA Technical Reports Server (NTRS)
Spry, David J.; Neudeck, Philip G.; Lukco, Dorothy; Chen, Liangyu; Krasowski, Michael J.; Prokop, Norman F.; Chang, Carl W.; Beheim, Glenn M.
2017-01-01
This report describes more than 5000 hours of successful 500 C operation of semiconductor integrated circuits (ICs) with more than 100 transistors. Multiple packaged chips with two different 4H-SiC junction field effect transistor (JFET) technology demonstrator circuits have surpassed thousands of hours of oven-testing at 500 C. After 100 hours of 500 C burn-in, the circuits (except for 2 failures) exhibit less than 10% change in output characteristics for the remainder of 500 C testing. We also describe the observation of important differences in IC materials durability when subjected to the first nine constituents of Venus-surface atmosphere at 9.4 MPa and 460 C in comparison to what is observed for Earth-atmosphere oven testing at 500 C.
Prolonged 500 C Operation of 100+ Transistor Silicon Carbide Integrated Circuits
NASA Technical Reports Server (NTRS)
Spry, David J.; Neudeck, Philip G.; Lukco, Dorothy; Chen, Liangyu; Krasowski, Michael J.; Prokop, Norman F.; Chang, Carl W.; Beheim, Glenn M.
2017-01-01
This report describes more than 5000 hours of successful 500 C operation of semiconductor integrated circuits (ICs) with more than 100 transistors. Multiple packaged chips with two different 4H-SiC junction field effect transistor (JFET) technology demonstrator circuits have surpassed thousands of hours of oven-testing at 500 C. After 100 hours of 500 C burn-in, the circuits (except for 2 failures) exhibit less than 10 change in output characteristics for the remainder of 500C testing. We also describe the observation of important differences in IC materials durability when subjected to the first nine constituents of Venus-surface atmosphere at 9.4 MPa and 460C in comparison to what is observed for Earth-atmosphere oven testing at 500 C.
A Powerful Test for Comparing Multiple Regression Functions.
Maity, Arnab
2012-09-01
In this article, we address the important problem of comparison of two or more population regression functions. Recently, Pardo-Fernández, Van Keilegom and González-Manteiga (2007) developed test statistics for simple nonparametric regression models: Y(ij) = θ(j)(Z(ij)) + σ(j)(Z(ij))∊(ij), based on empirical distributions of the errors in each population j = 1, … , J. In this paper, we propose a test for equality of the θ(j)(·) based on the concept of generalized likelihood ratio type statistics. We also generalize our test for other nonparametric regression setups, e.g, nonparametric logistic regression, where the loglikelihood for population j is any general smooth function [Formula: see text]. We describe a resampling procedure to obtain the critical values of the test. In addition, we present a simulation study to evaluate the performance of the proposed test and compare our results to those in Pardo-Fernández et al. (2007).
NASA Technical Reports Server (NTRS)
Boardman, T. A.; Carpenter, R. L.; Goldberg, B. E.; Shaeffer, C. W.
1993-01-01
Establishment of a test facility and associated 11-in.-diameter motor for hybrid propulsion technology development at NASA's George C. Marshall Space Flight Center is discussed in this paper. Results of twenty 11-in.-diameter motor tests with a UTF-29901 (60 percent polycyclopentadiene, 40 percent hydroxyl-terminated polybutadiene)/gaseous oxygen propellant system are presented. Tests at this scale have developed fuel regression correlations for comparison with results of yet-to-be-completed, 24-in.-diameter motor tests; demonstrated combustion efficiency levels in the 95 percent range for both single- and multiple-port grain configurations; have shown smooth and stable throttling characteristics over flight-type throttle ranges; and have begun to establish criteria for stable combustion in hybrid motors. The testing of 24-in. motors has not as yet been initiated and is not addressed.
Self-reported physical activity and preaccession fitness testing in U.S. Army applicants.
Gubata, Marlene E; Cowan, David N; Bedno, Sheryl A; Urban, Nadia; Niebuhr, David W
2011-08-01
The Assessment of Recruit Motivation and Strength (ARMS) study evaluated a physical fitness screening test for Army applicants before basic training. This report examines applicants' self-reported physical activity as a predictor of objective fitness measured by ARMS. In 2006, the ARMS study administered a fitness test and physical activity survey to Army applicants during their medical evaluation, using multiple logistic regression for comparison. Among both men and women, "qualified" and "exceeds-body-fat" subjects who met American College of Sports Medicine adult physical activity guidelines were more likely to pass the fitness test. Overall, subjects who met physical activity recommendations, watched less television, and played on sports teams had a higher odds of passing the ARMS test after adjustment for age, race, and smoking status. This study demonstrates that self-reported physical activity was associated with physical fitness and may be used to identify those at risk of failing a preaccession fitness test.
Johannesen, Jason K; Fiszdon, Joanna M; Weinstein, Andrea; Ciosek, David; Bell, Morris D
2018-04-01
The Social Attribution Task-Multiple Choice (SAT-MC) tests the ability to extract social themes from viewed object motion. This form of animacy perception is thought to aid the development of social inference, but appears impaired in schizophrenia. The current study was undertaken to examine psychometric equivalence of two forms of the SAT-MC and to compare their performance against social cognitive tests recommended for schizophrenia research. Thirty-two schizophrenia (SZ) and 30 substance use disorder (SUD) participants completed both SAT-MC forms, the Bell-Lysaker Emotion Recognition Task (BLERT), Hinting Task, The Awareness of Social Inference Test (TASIT), Ambiguous Intentions and Hostility Questionnaire (AIHQ) and questionnaire measures of interpersonal function. Test sensitivity, construct and external validity, test-retest reliability, and internal consistency were evaluated. SZ scored significantly lower than SUD on both SAT-MC forms, each classifying ~60% of SZ as impaired, compared with ~30% of SUD. SAT-MC forms demonstrated good test-retest and parallel form reliability, minimal practice effect, high internal consistency, and similar patterns of correlation with social cognitive and external validity measures. The SAT-MC compared favorably to recommended social cognitive tests across psychometric features and, with exception of TASIT, was most sensitive to impairment in schizophrenia when compared to a chronic substance use sample. Published by Elsevier B.V.
NASA Astrophysics Data System (ADS)
Mussen, Kimberly S.
This quantitative research study evaluated the effectiveness of employing pedagogy based on the theory of multiple intelligences (MI). Currently, not all students are performing at the rate mandated by the government. When schools do not meet the required state standards, the school is labeled as not achieving adequate yearly progress (AYP), which may lead to the loss of funding. Any school not achieving AYP would be interested in this study. Due to low state standardized test scores in the district for science, student achievement and attitudes towards learning science were evaluated on a pretest, posttest, essay question, and one attitudinal survey. Statistical significance existed on one of the four research questions. Utilizing the Analysis of Covariance (ANCOVA) for data analysis, student attitudes towards learning science were statically significant in the MI (experimental) group. No statistical significance was found in student achievement on the posttest, delayed posttest, or the essay question test. Social change can result from this study because studying the effects of the multiple intelligence theory incorporated into classroom instruction can have significant effect on how children learn, allowing them to compete in a knowledge society.
NASA Technical Reports Server (NTRS)
Feiveson, Alan H.; Ploutz-Snyder, Robert; Fiedler, James
2011-01-01
As part of a 2009 Annals of Statistics paper, Gavrilov, Benjamini, and Sarkar report results of simulations that estimated the false discovery rate (FDR) for equally correlated test statistics using a well-known multiple-test procedure. In our study we estimate the distribution of the false discovery proportion (FDP) for the same procedure under a variety of correlation structures among multiple dependent variables in a MANOVA context. Specifically, we study the mean (the FDR), skewness, kurtosis, and percentiles of the FDP distribution in the case of multiple comparisons that give rise to correlated non-central t-statistics when results at several time periods are being compared to baseline. Even if the FDR achieves its nominal value, other aspects of the distribution of the FDP depend on the interaction between signed effect sizes and correlations among variables, proportion of true nulls, and number of dependent variables. We show examples where the mean FDP (the FDR) is 10% as designed, yet there is a surprising probability of having 30% or more false discoveries. Thus, in a real experiment, the proportion of false discoveries could be quite different from the stipulated FDR.
Eckermann, Simon; Willan, Andrew R
2011-07-01
Multiple strategy comparisons in health technology assessment (HTA) are becoming increasingly important, with multiple alternative therapeutic actions, combinations of therapies and diagnostic and genetic testing alternatives. Comparison under uncertainty of incremental cost, effects and cost effectiveness across more than two strategies is conceptually and practically very different from that for two strategies, where all evidence can be summarized in a single bivariate distribution on the incremental cost-effectiveness plane. Alternative methods for comparing multiple strategies in HTA have been developed in (i) presenting cost and effects on the cost-disutility plane and (ii) summarizing evidence with multiple strategy cost-effectiveness acceptability (CEA) and expected net loss (ENL) curves and frontiers. However, critical questions remain for the analyst and decision maker of how these techniques can be best employed across multiple strategies to (i) inform clinical and cost inference in presenting evidence, and (ii) summarize evidence of cost effectiveness to inform societal reimbursement decisions where preferences may be risk neutral or somewhat risk averse under the Arrow-Lind theorem. We critically consider how evidence across multiple strategies can be best presented and summarized to inform inference and societal reimbursement decisions, given currently available methods. In the process, we make a number of important original findings. First, in presenting evidence for multiple strategies, the joint distribution of costs and effects on the cost-disutility plane with associated flexible comparators varying across replicates for cost and effect axes ensure full cost and effect inference. Such inference is usually confounded on the cost-effectiveness plane with comparison relative to a fixed origin and axes. Second, in summarizing evidence for risk-neutral societal decision making, ENL curves and frontiers are shown to have advantages over the CEA frontier in directly presenting differences in expected net benefit (ENB). The CEA frontier, while identifying strategies that maximize ENB, only presents their probability of maximizing net benefit (NB) and, hence, fails to explain why strategies maximize ENB at any given threshold value. Third, in summarizing evidence for somewhat risk-averse societal decision making, trade-offs between the strategy maximizing ENB and other potentially optimal strategies with higher probability of maximizing NB should be presented over discrete threshold values where they arise. However, the probabilities informing these trade-offs and associated discrete threshold value regions should be derived from bilateral CEA curves to prevent confounding by other strategies inherent in multiple strategy CEA curves. Based on these findings, a series of recommendations are made for best presenting and summarizing cost-effectiveness evidence for reimbursement decisions when comparing multiple strategies, which are contrasted with advice for comparing two strategies. Implications for joint research and reimbursement decisions are also discussed.
Bose-Einstein correlations in pp and PbPb collisions with ALICE at the LHC
Kisiel, Adam
2018-05-14
We report on the results of identical pion femtoscopy at the LHC. The Bose-Einstein correlation analysis was performed on the large-statistics ALICE p+p at sqrt{s}= 0.9 TeV and 7 TeV datasets collected during 2010 LHC running and the first Pb+Pb dataset at sqrt{s_NN}= 2.76 TeV. Detailed pion femtoscopy studies in heavy-ion collisions have shown that emission region sizes ("HBT radii") decrease with increasing pair momentum, which is understood as a manifestation of the collective behavior of matter. 3D radii were also found to universally scale with event multiplicity. In p+p collisions at 7 TeV one measures multiplicities which are comparable with those registered in peripheral AuAu and CuCu collisions at RHIC, so direct comparisons and tests of scaling laws are now possible. We show the results of double-differential 3D pion HBT analysis, as a function of multiplicity and pair momentum. The results for two collision energies are compared to results obtained in the heavy-ion collisions at similar multiplicity and p+p collisions at lower energy. We identify the relevant scaling variables for the femtoscopic radii and discuss the similarities and differences to results from heavy-ions. The observed trends give insight into the soft particle production mechanism in p+p collisions and suggest that a self-interacting collective system may be created in sufficiently high multiplicity events. First results for the central Pb+Pb collisions are also shown. A significant increase of the reaction zone volume and lifetime in comparison to RHIC is observed. Signatures of collective hydrodynamics-like behavior of the system are also apparent, and are compared to model predictions.
Negriff, Sonya; Brensilver, Matthew; Trickett, Penelope K.
2015-01-01
Purpose To test models linking pubertal timing, peer substance use, sexual behavior, and substance use for maltreated versus comparison adolescents. Three theoretical mechanisms were tested: 1) peer influence links early pubertal timing to later sexual behavior and substance use, 2) early maturers engage in substance use on their own and then select substance-using friends, or 3) early maturers initiate sexual behaviors which leads them to substance-using peers. Methods The data came from a longitudinal study of the effects of child maltreatment on adolescent development (303 maltreated and 151 comparison adolescents; age: 9–13 years at initial wave). Multiple-group structural equation models tested the hypotheses across three timepoints including variables of pubertal timing, perception of peer substance use, sexual behavior, and self-reported substance use. Results Early pubertal timing was associated with substance-using peers only for maltreated adolescents, indicating the mediation path from early pubertal timing through substance-using peers to subsequent adolescent substance use and sexual behavior only holds for maltreated adolescents. Mediation via sexual behavior was significant for both maltreated and comparison adolescents. This indicates that sexual behavior may be a more universal mechanism linking early maturation with risky friends regardless of adverse life experiences. Conclusions The findings are a step toward elucidating the developmental pathways from early puberty to risk behavior and identifying early experiences that may alter mediation effects. PMID:26003577
NASA Technical Reports Server (NTRS)
Lucy, M. H.; Buehrle, R. D.; Woolley, J. P.
1996-01-01
Functional shock, safety, overall system costs, and emergence of new technologies, have raised concerns regarding continued use of pyrotechnics on spacecraft. NASA Headquarters-Office of Chief Engineer requested Langley Research Center (LaRC) study pyrotechnic alternatives using non-explosive actuators (NEA's), and LARC participated with Lockheed Martin Missile and Space Co. (LMMSC)-Sunnyvale, CA in objectively evaluating applicability of some NEA mechanisms to reduce small spacecraft and booster separation event shock. Comparative tests were conducted on a structural simulator using five different separation nut mechanisms, consisting of three pyrotechnics from OEA-Aerospace and Hi-Shear Technology and two NEA's from G&H Technology and Lockheed Martin Astronautics (LMA)-Denver, CO. Multiple actuations were performed with preloads up to 7000 pounds, 7000 being the comparison standard. All devices except LMA's NEA rotary flywheel-nut concept were available units with no added provisions to attenuate shock. Accelerometer measurements were recorded, reviewed, processed into Shock Response Spectra (SRS), and comparisons performed. For the standard preload, pyrotechnics produced the most severe and the G&H NEA the least severe functional shock levels. Comparing all results, the LMA concept produced the lowest levels, with preload limited to approximately 4200 pounds. Testing this concept over a range of 3000 to 4200 pounds indicated no effect of preload on shock response levels. This report presents data from these tests and the comparative results.
Negriff, Sonya; Trickett, Penelope K
2012-11-01
Early pubertal timing has received considerable empirical support as a risk for adolescent substance use. However, few studies have examined the mediators linking these variables. Therefore, the aims of this study were (1) to examine peer substance use as a mediator between pubertal timing and adolescent substance use longitudinally and (2) to test gender and maltreatment experience as moderators of the mediational model. Data were obtained from time 1, 2, and 3 of a longitudinal study of maltreatment and development. At time 1 the sample was comprised of 303 maltreated and 151 comparison children aged 9-13 years (213 females and 241 males). Longitudinal mediation was tested using structural equation modeling and moderating effects were tested using multiple group analysis. Peer substance use mediated the relationship between early pubertal timing and later adolescent substance use for the total sample. Moderation analyses indicated this significant indirect effect did not differ for males and females. However, it did differ for maltreated versus comparison adolescents with the mediational effect only remaining significant for the comparison group. This is one of the first studies to examine peer substance use as a mediator of pubertal timing and adolescent substance use using a longitudinal design. Early maturing males are at equal risk to early maturing females for interacting with peers that may draw them into substance use. Additionally, the findings indicate that while peers are mediators for comparison adolescents a different mechanism may link early puberty to substance use for maltreated adolescents. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.
Evaluation of a Traffic Sign Detector by Synthetic Image Data for Advanced Driver Assistance Systems
NASA Astrophysics Data System (ADS)
Hanel, A.; Kreuzpaintner, D.; Stilla, U.
2018-05-01
Recently, several synthetic image datasets of street scenes have been published. These datasets contain various traffic signs and can therefore be used to train and test machine learning-based traffic sign detectors. In this contribution, selected datasets are compared regarding ther applicability for traffic sign detection. The comparison covers the process to produce the synthetic images and addresses the virtual worlds, needed to produce the synthetic images, and their environmental conditions. The comparison covers variations in the appearance of traffic signs and the labeling strategies used for the datasets, as well. A deep learning traffic sign detector is trained with multiple training datasets with different ratios between synthetic and real training samples to evaluate the synthetic SYNTHIA dataset. A test of the detector on real samples only has shown that an overall accuracy and ROC AUC of more than 95 % can be achieved for both a small rate of synthetic samples and a large rate of synthetic samples in the training dataset.
Mausbach, Brent T; Tiznado, Denisse; Cardenas, Veronica; Jeste, Dilip V; Patterson, Thomas L
2016-10-30
The UCSD Performance-based Skills Assessment (UPSA) is a widely used measure of functional capacity with strong reliability and validity. However there is a lack of psychometric data on Hispanics. The purpose of this study was to determine the impact of acculturation and education on UPSA performance among 62 Hispanic participants with schizophrenia or schizoaffective disorder and 46 healthy comparison subjects. Functional capacity was measured using the UPSA. Acculturation was measured using the Acculturation Rating Scale for Mexican Americans (ARSMA). Independent t-tests indicated that participants with schizophrenia had significantly lower UPSA total scores and scored lower on all UPSA sub-scales relative to the comparison group. Multiple regression also indicated that education and acculturation were significant predictors of UPSA total scores. These data provide a better understanding of UPSA scores in Hispanics with and without schizophrenia, and suggest that education and acculturation adjustments may be required to improve interpretation of test results. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
A Bayesian Missing Data Framework for Generalized Multiple Outcome Mixed Treatment Comparisons
ERIC Educational Resources Information Center
Hong, Hwanhee; Chu, Haitao; Zhang, Jing; Carlin, Bradley P.
2016-01-01
Bayesian statistical approaches to mixed treatment comparisons (MTCs) are becoming more popular because of their flexibility and interpretability. Many randomized clinical trials report multiple outcomes with possible inherent correlations. Moreover, MTC data are typically sparse (although richer than standard meta-analysis, comparing only two…
A Fiducial Approach to Extremes and Multiple Comparisons
ERIC Educational Resources Information Center
Wandler, Damian V.
2010-01-01
Generalized fiducial inference is a powerful tool for many difficult problems. Based on an extension of R. A. Fisher's work, we used generalized fiducial inference for two extreme value problems and a multiple comparison procedure. The first extreme value problem is dealing with the generalized Pareto distribution. The generalized Pareto…
Clinical Development of Gamitrinib, a Novel Mitochondrial-Targeted Small Molecule Hsp90 Inhibitor
2015-09-01
Group 2 and Group 3 animals examined at the end of the 7-repeated doses was comparable to those in control Group 1 animals (Figure 2). (7) Despite... posttest (for more than two- group comparisons) using a GraphPad software package (Prism 6.0) for Windows. Data are expressed as mean ± SD or mean ± SEM...Benjamini Y, Hochberg Y (1995) Controlling the false discovery rate: A practical and powerful approach to multiple testing. J R Stat Soc Series B Stat
NASA Technical Reports Server (NTRS)
Dehon, Rene
1992-01-01
The objectives are characterization of flow through outflow channels, sedimentation associated with Martian outflow systems, and documentation of Martian lakes. Over the period of the grant much, but not all, of the study centered on the Maja Valles outflow. Maja served as an example in which the effects of multiple channel routing and ponding could be studied. Maja Valles also served as the test case for calculating flow through an outflow system. Applying the lessons learned in Maja Valles and comparisons and contrast required a scrutiny of other channels.
2008-05-02
CAPE CANAVERAL, Fla. -- Artist's rendering of the Constellation Program's Ares V rocket on the mobile launcher platform (left) and the Ares I rocket on the platform (right) with the space shuttle in between for comparison. The tower of the mobile launcher will have multiple platforms for personnel access and will be approximately 390 feet tall. The tower will be used in the assembly, testing and servicing of the Ares rockets at Kennedy and will also transport the Ares rockets to the launch pad and provide ground support for launches.
Sympathetic Nerves in Breast Cancer: Angiogenesis and Antiangiogenic Therapy
2013-02-01
directly regulate 4T1 growth through ARs. Using in vitro conditions that yielded NE-mediated functional effects in other cell lines (1), we assessed...Therefore we propose that 4T1 is a good model for examining the effects of NE-induced effects on stromal cell populations in the absence of direct NE... effects analysis or by Holm-Sidak multiple comparison test. RESULTS 4T1 Tumor Cells Do Not Respond to NE In Vitro or Signal via AR To determine
1993-03-01
statistical mathe- matics, began in the late 1800’s when Sir Francis Galton first attempted to use practical mathematical techniques to investigate the...randomly collected (sampled) many pairs of parent/child height mea- surements (data), Galton observed that for a given parent- height average, the...ty only Maximum Adjusted R2 will be discussed. However, Maximum Adjusted R’ and Minimum MSE test exactly the same 2.thing. Adjusted R is related to R
Similarity indices of meteo-climatic gauging stations: definition and comparison.
Barca, Emanuele; Bruno, Delia Evelina; Passarella, Giuseppe
2016-07-01
Space-time dependencies among monitoring network stations have been investigated to detect and quantify similarity relationships among gauging stations. In this work, besides the well-known rank correlation index, two new similarity indices have been defined and applied to compute the similarity matrix related to the Apulian meteo-climatic monitoring network. The similarity matrices can be applied to address reliably the issue of missing data in space-time series. In order to establish the effectiveness of the similarity indices, a simulation test was then designed and performed with the aim of estimating missing monthly rainfall rates in a suitably selected gauging station. The results of the simulation allowed us to evaluate the effectiveness of the proposed similarity indices. Finally, the multiple imputation by chained equations method was used as a benchmark to have an absolute yardstick for comparing the outcomes of the test. In conclusion, the new proposed multiplicative similarity index resulted at least as reliable as the selected benchmark.
FEENAUGHTY, LYNDA; TJADEN, KRIS; BENEDICT, RALPH H.B.; WEINSTOCK-GUTTMAN, BIANCA
2017-01-01
This preliminary study investigated how cognitive-linguistic status in multiple sclerosis (MS) is reflected in two speech tasks (i.e. oral reading, narrative) that differ in cognitive-linguistic demand. Twenty individuals with MS were selected to comprise High and Low performance groups based on clinical tests of executive function and information processing speed and efficiency. Ten healthy controls were included for comparison. Speech samples were audio-recorded and measures of global speech timing were obtained. Results indicated predicted differences in global speech timing (i.e. speech rate and pause characteristics) for speech tasks differing in cognitive-linguistic demand, but the magnitude of these task-related differences was similar for all speaker groups. Findings suggest that assumptions concerning the cognitive-linguistic demands of reading aloud as compared to spontaneous speech may need to be re-considered for individuals with cognitive impairment. Qualitative trends suggest that additional studies investigating the association between cognitive-linguistic and speech motor variables in MS are warranted. PMID:23294227
Park, Sang Cheol; Leader, Joseph Ken; Tan, Jun; Lee, Guee Sang; Kim, Soo Hyung; Na, In Seop; Zheng, Bin
2011-01-01
Objective this article presents a new computerized scheme that aims to accurately and robustly separate left and right lungs on CT examinations. Methods we developed and tested a method to separate the left and right lungs using sequential CT information and a guided dynamic programming algorithm using adaptively and automatically selected start point and end point with especially severe and multiple connections. Results the scheme successfully identified and separated all 827 connections on the total 4034 CT images in an independent testing dataset of CT examinations. The proposed scheme separated multiple connections regardless of their locations, and the guided dynamic programming algorithm reduced the computation time to approximately 4.6% in comparison with the traditional dynamic programming and avoided the permeation of the separation boundary into normal lung tissue. Conclusions The proposed method is able to robustly and accurately disconnect all connections between left and right lungs and the guided dynamic programming algorithm is able to remove redundant processing. PMID:21412104
Lin-Gibson, Sheng; Sung, Lipiin; Forster, Aaron M; Hu, Haiqing; Cheng, Yajun; Lin, Nancy J
2009-07-01
Multicomponent formulations coupled with complex processing conditions govern the final properties of photopolymerizable dental composites. In this study, a single test substrate was fabricated to support multiple formulations with a gradient in degree of conversion (DC), allowing the evaluation of multiple processing conditions and formulations on one specimen. Mechanical properties and damage response were evaluated as a function of filler type/content and irradiation. DC, surface roughness, modulus, hardness, scratch deformation and cytotoxicity were quantified using techniques including near-infrared spectroscopy, laser confocal scanning microscopy, depth-sensing indentation, scratch testing and cell viability. Scratch parameters (depth, width, percent recovery) were correlated to composite modulus and hardness. Total filler content, nanofiller and irradiation time/intensity all affected the final properties, with the dominant factor for improved properties being a higher DC. This combinatorial platform accelerates the screening of dental composites through the direct comparison of properties and processing conditions across the same sample.
Park, Sang Cheol; Leader, Joseph Ken; Tan, Jun; Lee, Guee Sang; Kim, Soo Hyung; Na, In Seop; Zheng, Bin
2011-01-01
This article presents a new computerized scheme that aims to accurately and robustly separate left and right lungs on computed tomography (CT) examinations. We developed and tested a method to separate the left and right lungs using sequential CT information and a guided dynamic programming algorithm using adaptively and automatically selected start point and end point with especially severe and multiple connections. The scheme successfully identified and separated all 827 connections on the total 4034 CT images in an independent testing data set of CT examinations. The proposed scheme separated multiple connections regardless of their locations, and the guided dynamic programming algorithm reduced the computation time to approximately 4.6% in comparison with the traditional dynamic programming and avoided the permeation of the separation boundary into normal lung tissue. The proposed method is able to robustly and accurately disconnect all connections between left and right lungs, and the guided dynamic programming algorithm is able to remove redundant processing.
ERDEMİR, Ugur; YİLDİZ, Esra; EREN, Meltem Mert; OZEL, Sevda
2013-01-01
Objectives: This study evaluated the effect of sports and energy drinks on the surface hardness of different composite resin restorative materials over a 1-month period. Material and Methods: A total of 168 specimens: Compoglass F, Filtek Z250, Filtek Supreme, and Premise were prepared using a customized cylindrical metal mould and they were divided into six groups (N=42; n=7 per group). For the control groups, the specimens were stored in distilled water for 24 hours at 37º C and the water was renewed daily. For the experimental groups, the specimens were immersed in 5 mL of one of the following test solutions: Powerade, Gatorade, X-IR, Burn, and Red Bull, for two minutes daily for up to a 1-month test period and all the solutions were refreshed daily. Surface hardness was measured using a Vickers hardness measuring instrument at baseline, after 1-week and 1-month. Data were statistically analyzed using Multivariate repeated measure ANOVA and Bonferroni's multiple comparison tests (α=0.05). Results: Multivariate repeated measures ANOVA revealed that there were statistically significant differences in the hardness of the restorative materials in different immersion times (p<0.001) in different solutions (p<0.001). The effect of different solutions on the surface hardness values of the restorative materials was tested using Bonferroni's multiple comparison tests, and it was observed that specimens stored in distilled water demonstrated statistically significant lower mean surface hardness reductions when compared to the specimens immersed in sports and energy drinks after a 1-month evaluation period (p<0.001). The compomer was the most affected by an acidic environment, whereas the composite resin materials were the least affected materials. Conclusions: The effect of sports and energy drinks on the surface hardness of a restorative material depends on the duration of exposure time, and the composition of the material. PMID:23739850
NASA Astrophysics Data System (ADS)
Murakami, H.; Chen, X.; Hahn, M. S.; Over, M. W.; Rockhold, M. L.; Vermeul, V.; Hammond, G. E.; Zachara, J. M.; Rubin, Y.
2010-12-01
Subsurface characterization for predicting groundwater flow and contaminant transport requires us to integrate large and diverse datasets in a consistent manner, and quantify the associated uncertainty. In this study, we sequentially assimilated multiple types of datasets for characterizing a three-dimensional heterogeneous hydraulic conductivity field at the Hanford 300 Area. The datasets included constant-rate injection tests, electromagnetic borehole flowmeter tests, lithology profile and tracer tests. We used the method of anchored distributions (MAD), which is a modular-structured Bayesian geostatistical inversion method. MAD has two major advantages over the other inversion methods. First, it can directly infer a joint distribution of parameters, which can be used as an input in stochastic simulations for prediction. In MAD, in addition to typical geostatistical structural parameters, the parameter vector includes multiple point values of the heterogeneous field, called anchors, which capture local trends and reduce uncertainty in the prediction. Second, MAD allows us to integrate the datasets sequentially in a Bayesian framework such that it updates the posterior distribution, as a new dataset is included. The sequential assimilation can decrease computational burden significantly. We applied MAD to assimilate different combinations of the datasets, and then compared the inversion results. For the injection and tracer test assimilation, we calculated temporal moments of pressure build-up and breakthrough curves, respectively, to reduce the data dimension. A massive parallel flow and transport code PFLOTRAN is used for simulating the tracer test. For comparison, we used different metrics based on the breakthrough curves not used in the inversion, such as mean arrival time, peak concentration and early arrival time. This comparison intends to yield the combined data worth, i.e. which combination of the datasets is the most effective for a certain metric, which will be useful for guiding the further characterization effort at the site and also the future characterization projects at the other sites.
Baxter, Melissa; Withey, Sarah; Harrison, Sean; Segeritz, Charis-Patricia; Zhang, Fang; Atkinson-Dell, Rebecca; Rowe, Cliff; Gerrard, Dave T; Sison-Young, Rowena; Jenkins, Roz; Henry, Joanne; Berry, Andrew A; Mohamet, Lisa; Best, Marie; Fenwick, Stephen W; Malik, Hassan; Kitteringham, Neil R; Goldring, Chris E; Piper Hanley, Karen; Vallier, Ludovic; Hanley, Neil A
2015-03-01
Hepatocyte-like cells (HLCs), differentiated from pluripotent stem cells by the use of soluble factors, can model human liver function and toxicity. However, at present HLC maturity and whether any deficit represents a true fetal state or aberrant differentiation is unclear and compounded by comparison to potentially deteriorated adult hepatocytes. Therefore, we generated HLCs from multiple lineages, using two different protocols, for direct comparison with fresh fetal and adult hepatocytes. Protocols were developed for robust differentiation. Multiple transcript, protein and functional analyses compared HLCs to fresh human fetal and adult hepatocytes. HLCs were comparable to those of other laboratories by multiple parameters. Transcriptional changes during differentiation mimicked human embryogenesis and showed more similarity to pericentral than periportal hepatocytes. Unbiased proteomics demonstrated greater proximity to liver than 30 other human organs or tissues. However, by comparison to fresh material, HLC maturity was proven by transcript, protein and function to be fetal-like and short of the adult phenotype. The expression of 81% phase 1 enzymes in HLCs was significantly upregulated and half were statistically not different from fetal hepatocytes. HLCs secreted albumin and metabolized testosterone (CYP3A) and dextrorphan (CYP2D6) like fetal hepatocytes. In seven bespoke tests, devised by principal components analysis to distinguish fetal from adult hepatocytes, HLCs from two different source laboratories consistently demonstrated fetal characteristics. HLCs from different sources are broadly comparable with unbiased proteomic evidence for faithful differentiation down the liver lineage. This current phenotype mimics human fetal rather than adult hepatocytes. Copyright © 2014 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.
Apparently abnormal Wechsler Memory Scale index score patterns in the normal population.
Carrasco, Roman Marcus; Grups, Josefine; Evans, Brittney; Simco, Edward; Mittenberg, Wiley
2015-01-01
Interpretation of the Wechsler Memory Scale-Fourth Edition may involve examination of multiple memory index score contrasts and similar comparisons with Wechsler Adult Intelligence Scale-Fourth Edition ability indexes. Standardization sample data suggest that 15-point differences between any specific pair of index scores are relatively uncommon in normal individuals, but these base rates refer to a comparison between a single pair of indexes rather than multiple simultaneous comparisons among indexes. This study provides normative data for the occurrence of multiple index score differences calculated by using Monte Carlo simulations and validated against standardization data. Differences of 15 points between any two memory indexes or between memory and ability indexes occurred in 60% and 48% of the normative sample, respectively. Wechsler index score discrepancies are normally common and therefore not clinically meaningful when numerous such comparisons are made. Explicit prior interpretive hypotheses are necessary to reduce the number of index comparisons and associated false-positive conclusions. Monte Carlo simulation accurately predicts these false-positive rates.
Bradley, Jennifer; Simpson, Emma; Poliakov, Ivan; Matthews, John N S; Olivier, Patrick; Adamson, Ashley J; Foster, Emma
2016-06-09
Online dietary assessment tools offer a convenient, low cost alternative to traditional dietary assessment methods such as weighed records and face-to-face interviewer-led 24-h recalls. INTAKE24 is an online multiple pass 24-h recall tool developed for use with 11-24 year-old. The aim of the study was to undertake a comparison of INTAKE24 (the test method) with interviewer-led multiple pass 24-h recalls (the comparison method) in 180 people aged 11-24 years. Each participant completed both an INTAKE24 24-h recall and an interviewer-led 24-h recall on the same day on four occasions over a one-month period. The daily energy and nutrient intakes reported in INTAKE24 were compared to those reported in the interviewer-led recall. Mean intakes reported using INTAKE24 were similar to the intakes reported in the interviewer-led recall for energy and macronutrients. INTAKE24 was found to underestimate energy intake by 1% on average compared to the interviewer-led recall with the limits of agreement ranging from minus 49% to plus 93%. Mean intakes of all macronutrients and micronutrients (except non-milk extrinsic sugars) were within 4% of the interviewer-led recall. Dietary assessment that utilises technology may offer a viable alternative and be more engaging than paper based methods, particularly for children and young adults.
NASA Technical Reports Server (NTRS)
Kim, Y. W.; Metzger, D. E.
1992-01-01
The test facility, test methods and results are presented for an experimental study modeling the cooling of turbine disks in the blade attachment regions with multiple impinging jets, in a configuration simulating the disk cooling method employed on the Space Shuttle Main Engine oxygen turbopump. The study's objective was to provide a comparison of detailed local convection heat transfer rates obtained for a single center-supply of disk coolant with those obtained with the present flight configuration where disk coolant is supplied through an array of 19 jets located near the disk outer radius. Specially constructed disk models were used in a program designed to evaluate possible benefits and identify any possible detrimental effects involved in employing an alternate disk cooling scheme. The study involved the design, construction and testing of two full scale rotating model disks, one plane and smooth for baseline testing and the second contoured to the present flight configuration, together with the corresponding plane and contoured stator disks. Local heat transfer rates are determined from the color display of encapsulated liquid crystals coated on the disk in conjunction with use of a computer vision system. The test program was composed of a wide variety of disk speeds, flowrates, and geometrical configurations, including testing for the effects of disk boltheads and gas ingestion from the gas path region radially outboard of the disk-cavity.
Vaccarella, Salvatore; Söderlund-Strand, Anna; Franceschi, Silvia; Plummer, Martyn; Dillner, Joakim
2013-01-01
To evaluate the pattern of co-infection of human papillomavirus (HPV) types in both sexes in Sweden. Cell samples from genital swabs, first-void urine, and genital swabs immersed in first-void urine were collected in the present cross-sectional High Throughput HPV Monitoring study. Overall, 31,717 samples from women and 9,949 from men (mean age 25) were tested for 16 HPV types using mass spectrometry. Multilevel logistic regression was used to estimate the expected number of multiple infections with specific HPV types, adjusted for age, type of sample, and accounting for correlations between HPV types due to unobserved risk factors using sample-level random effects. Bonferroni correction was used to allow for multiple comparisons (120). Observed-to-expected ratio for any multiple infections was slightly above unity in both sexes, but, for most 2-type combinations, there was no evidence of significant departure from expected numbers. HPV6/18 was found more often and HPV51/68 and 6/68 less often than expected. However, HPV68 tended to be generally underrepresented in co-infections, suggesting a sub-optimal performance of our testing method for this HPV type. We found no evidence for positive or negative clustering between HPV types included in the current prophylactic vaccines and other untargeted oncogenic types, in either sex.
MAAMD: a workflow to standardize meta-analyses and comparison of affymetrix microarray data
2014-01-01
Background Mandatory deposit of raw microarray data files for public access, prior to study publication, provides significant opportunities to conduct new bioinformatics analyses within and across multiple datasets. Analysis of raw microarray data files (e.g. Affymetrix CEL files) can be time consuming, complex, and requires fundamental computational and bioinformatics skills. The development of analytical workflows to automate these tasks simplifies the processing of, improves the efficiency of, and serves to standardize multiple and sequential analyses. Once installed, workflows facilitate the tedious steps required to run rapid intra- and inter-dataset comparisons. Results We developed a workflow to facilitate and standardize Meta-Analysis of Affymetrix Microarray Data analysis (MAAMD) in Kepler. Two freely available stand-alone software tools, R and AltAnalyze were embedded in MAAMD. The inputs of MAAMD are user-editable csv files, which contain sample information and parameters describing the locations of input files and required tools. MAAMD was tested by analyzing 4 different GEO datasets from mice and drosophila. MAAMD automates data downloading, data organization, data quality control assesment, differential gene expression analysis, clustering analysis, pathway visualization, gene-set enrichment analysis, and cross-species orthologous-gene comparisons. MAAMD was utilized to identify gene orthologues responding to hypoxia or hyperoxia in both mice and drosophila. The entire set of analyses for 4 datasets (34 total microarrays) finished in ~ one hour. Conclusions MAAMD saves time, minimizes the required computer skills, and offers a standardized procedure for users to analyze microarray datasets and make new intra- and inter-dataset comparisons. PMID:24621103
Bagley, Justin C; Johnson, Jerald B
2014-01-01
A central goal of comparative phylogeography is determining whether codistributed species experienced (1) concerted evolutionary responses to past geological and climatic events, indicated by congruent spatial and temporal patterns (“concerted-response hypothesis”); (2) independent responses, indicated by spatial incongruence (“independent-response hypothesis”); or (3) multiple responses (“multiple-response hypothesis”), indicated by spatial congruence but temporal incongruence (“pseudocongruence”) or spatial and temporal incongruence (“pseudoincongruence”). We tested these competing hypotheses using DNA sequence data from three livebearing fish species codistributed in the Nicaraguan depression of Central America (Alfaro cultratus, Poecilia gillii, and Xenophallus umbratilis) that we predicted might display congruent responses due to co-occurrence in identical freshwater drainages. Spatial analyses recovered different subdivisions of genetic structure for each species, despite shared finer-scale breaks in northwestern Costa Rica (also supported by phylogenetic results). Isolation-with-migration models estimated incongruent timelines of among-region divergences, with A. cultratus and Xenophallus populations diverging over Miocene–mid-Pleistocene while P. gillii populations diverged over mid-late Pleistocene. Approximate Bayesian computation also lent substantial support to multiple discrete divergences over a model of simultaneous divergence across shared spatial breaks (e.g., Bayes factor [B10] = 4.303 for Ψ [no. of divergences] > 1 vs. Ψ = 1). Thus, the data support phylogeographic pseudoincongruence consistent with the multiple-response hypothesis. Model comparisons also indicated incongruence in historical demography, for example, support for intraspecific late Pleistocene population growth was unique to P. gillii, despite evidence for finer-scale population expansions in the other taxa. Empirical tests for phylogeographic congruence indicate that multiple evolutionary responses to historical events have shaped the population structure of freshwater species codistributed within the complex landscapes in/around the Nicaraguan depression. Recent community assembly through different routes (i.e., different past distributions or colonization routes), and intrinsic ecological differences among species, has likely contributed to the unique phylogeographical patterns displayed by these Neotropical fishes. PMID:24967085
Analysis and prediction of Multiple-Site Damage (MSD) fatigue crack growth
NASA Technical Reports Server (NTRS)
Dawicke, D. S.; Newman, J. C., Jr.
1992-01-01
A technique was developed to calculate the stress intensity factor for multiple interacting cracks. The analysis was verified through comparison with accepted methods of calculating stress intensity factors. The technique was incorporated into a fatigue crack growth prediction model and used to predict the fatigue crack growth life for multiple-site damage (MSD). The analysis was verified through comparison with experiments conducted on uniaxially loaded flat panels with multiple cracks. Configuration with nearly equal and unequal crack distribution were examined. The fatigue crack growth predictions agreed within 20 percent of the experimental lives for all crack configurations considered.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Klasky, Marc Louis; Myers, Steven Charles; James, Michael R.
To facilitate the timely execution of System Threat Reviews (STRs) for DNDO, and also to develop a methodology for performing STRs, LANL performed comparisons of several radiation transport codes (MCNP, GADRAS, and Gamma-Designer) that have been previously utilized to compute radiation signatures. While each of these codes has strengths, it is of paramount interest to determine the limitations of each of the respective codes and also to identify the most time efficient means by which to produce computational results, given the large number of parametric cases that are anticipated in performing STR's. These comparisons serve to identify regions of applicabilitymore » for each code and provide estimates of uncertainty that may be anticipated. Furthermore, while performing these comparisons, examination of the sensitivity of the results to modeling assumptions was also examined. These investigations serve to enable the creation of the LANL methodology for performing STRs. Given the wide variety of radiation test sources, scenarios, and detectors, LANL calculated comparisons of the following parameters: decay data, multiplicity, device (n,γ) leakages, and radiation transport through representative scenes and shielding. This investigation was performed to understand potential limitations utilizing specific codes for different aspects of the STR challenges.« less
Comparision of Immunohistochemical Expression of CD10 in Odontogenic Cysts
Munisekhar, M.S.; Suri, Charu; Rajalbandi, Santosh Kumar; M.R., Pradeep; Gothe, Pavan
2014-01-01
Background: Expression of CD10 has been documented in various tumors like nasopharyngeal carcinoma, gastric carcinoma, squamous cell carcinoma, odontogenic tumors. Aim: To evaluate and compare CD10 expression in odontogenic cysts like radicular cyst, dentigerous cyst and odontogenic keratocyst (OKC). Materials and Methods: Total 60 cases were included in the study, comprising 20 cases each of radicular, dentigerous and odontogenic keratocyst. Each case was evaluated and compared for immunohistochemical expression of CD10. Results obtained were statistically analysed using ANOVA test followed by post hoc test Tukey-Kramer Multiple Comparisons Test for continuous variable and Chi-square test for discrete variable. Results: More number of cases showing sub-epithelial stromal CD10 expression were found in OKC among the cysts. Conclusion: CD10 expression was more in OKC compared to radicular and dentigerous cysts. PMID:25584313
Li, Ying; Shi, Xiaohu; Liang, Yanchun; Xie, Juan; Zhang, Yu; Ma, Qin
2017-01-21
RNAs have been found to carry diverse functionalities in nature. Inferring the similarity between two given RNAs is a fundamental step to understand and interpret their functional relationship. The majority of functional RNAs show conserved secondary structures, rather than sequence conservation. Those algorithms relying on sequence-based features usually have limitations in their prediction performance. Hence, integrating RNA structure features is very critical for RNA analysis. Existing algorithms mainly fall into two categories: alignment-based and alignment-free. The alignment-free algorithms of RNA comparison usually have lower time complexity than alignment-based algorithms. An alignment-free RNA comparison algorithm was proposed, in which novel numerical representations RNA-TVcurve (triple vector curve representation) of RNA sequence and corresponding secondary structure features are provided. Then a multi-scale similarity score of two given RNAs was designed based on wavelet decomposition of their numerical representation. In support of RNA mutation and phylogenetic analysis, a web server (RNA-TVcurve) was designed based on this alignment-free RNA comparison algorithm. It provides three functional modules: 1) visualization of numerical representation of RNA secondary structure; 2) detection of single-point mutation based on secondary structure; and 3) comparison of pairwise and multiple RNA secondary structures. The inputs of the web server require RNA primary sequences, while corresponding secondary structures are optional. For the primary sequences alone, the web server can compute the secondary structures using free energy minimization algorithm in terms of RNAfold tool from Vienna RNA package. RNA-TVcurve is the first integrated web server, based on an alignment-free method, to deliver a suite of RNA analysis functions, including visualization, mutation analysis and multiple RNAs structure comparison. The comparison results with two popular RNA comparison tools, RNApdist and RNAdistance, showcased that RNA-TVcurve can efficiently capture subtle relationships among RNAs for mutation detection and non-coding RNA classification. All the relevant results were shown in an intuitive graphical manner, and can be freely downloaded from this server. RNA-TVcurve, along with test examples and detailed documents, are available at: http://ml.jlu.edu.cn/tvcurve/ .
A default Bayesian hypothesis test for mediation.
Nuijten, Michèle B; Wetzels, Ruud; Matzke, Dora; Dolan, Conor V; Wagenmakers, Eric-Jan
2015-03-01
In order to quantify the relationship between multiple variables, researchers often carry out a mediation analysis. In such an analysis, a mediator (e.g., knowledge of a healthy diet) transmits the effect from an independent variable (e.g., classroom instruction on a healthy diet) to a dependent variable (e.g., consumption of fruits and vegetables). Almost all mediation analyses in psychology use frequentist estimation and hypothesis-testing techniques. A recent exception is Yuan and MacKinnon (Psychological Methods, 14, 301-322, 2009), who outlined a Bayesian parameter estimation procedure for mediation analysis. Here we complete the Bayesian alternative to frequentist mediation analysis by specifying a default Bayesian hypothesis test based on the Jeffreys-Zellner-Siow approach. We further extend this default Bayesian test by allowing a comparison to directional or one-sided alternatives, using Markov chain Monte Carlo techniques implemented in JAGS. All Bayesian tests are implemented in the R package BayesMed (Nuijten, Wetzels, Matzke, Dolan, & Wagenmakers, 2014).
ERIC Educational Resources Information Center
Stipancic, Kaila L.; Tjaden, Kris; Wilding, Gregory
2016-01-01
Purpose: This study obtained judgments of sentence intelligibility using orthographic transcription for comparison with previously reported intelligibility judgments obtained using a visual analog scale (VAS) for individuals with Parkinson's disease and multiple sclerosis and healthy controls (K. Tjaden, J. E. Sussman, & G. E. Wilding, 2014).…
NASA Astrophysics Data System (ADS)
Brankov, Elvira
This thesis presents a methodology for examining the relationship between synoptic-scale atmospheric transport patterns and observed pollutant concentration levels. It involves calculating a large number of back-trajectories from the observational site and subjecting them to cluster analysis. The pollutant concentration data observed at that site are then segregated according to the back-trajectory clusters. If the pollutant observations extend over several seasons, it is important to filter out seasonal and long-term components from the time series data before pollutant cluster-segregation, because only the short-term component of the time series data is related to the synoptic-scale transport. Multiple comparison procedures are used to test for significant differences in the chemical composition of pollutant data associated with each cluster. This procedure is useful in indicating potential pollutant source regions and isolating meteorological regimes associated with pollutant transport from those regions. If many observational sites are available, the spatial and temporal scales of the pollution transport from a given direction can be extracted through the time-lagged inter- site correlation analysis of pollutant concentrations. The proposed methodology is applicable to any pollutant at any site if sufficiently abundant data set is available. This is illustrated through examination of five-year long time series data of ozone concentrations at several sites in the Northeast. The results provide evidence of ozone transport to these sites, revealing the characteristic spatial and temporal scales involved in the transport and identifying source regions for this pollutant. Problems related to statistical analyses of censored data are addressed in the second half of this thesis. Although censoring (reporting concentrations in a non-quantitative way) is typical for trace-level measurements, methods for statistical analysis, inference and interpretation of such data are complex and still under development. In this study, multiple comparison of censored data sets was required in order to examine the influence of synoptic- scale circulations on concentration levels of several trace-level toxic pollutants observed in the Northeast (e.g., As, Se, Mn, V, etc.). Since the traditional multiple comparison procedures are not readily applicable to such data sets, a Monte Carlo simulation study was performed to assess several nonparametric methods for multiple comparison of censored data sets. Application of an appropriate comparison procedure to clusters of toxic trace elements observed in the Northeast led to the identification of potential source regions and atmospheric patterns associated with the long-range transport of these pollutants. A method for comparison of proportions and elemental ratio calculations were used to confirm/clarify these inferences with a greater degree of confidence.
Limited Rationality and Its Quantification Through the Interval Number Judgments With Permutations.
Liu, Fang; Pedrycz, Witold; Zhang, Wei-Guo
2017-12-01
The relative importance of alternatives expressed in terms of interval numbers in the fuzzy analytic hierarchy process aims to capture the uncertainty experienced by decision makers (DMs) when making a series of comparisons. Under the assumption of full rationality, the judgements of DMs in the typical analytic hierarchy process could be consistent. However, since the uncertainty in articulating the opinions of DMs is unavoidable, the interval number judgements are associated with the limited rationality. In this paper, we investigate the concept of limited rationality by introducing interval multiplicative reciprocal comparison matrices. By analyzing the consistency of interval multiplicative reciprocal comparison matrices, it is observed that the interval number judgements are inconsistent. By considering the permutations of alternatives, the concepts of approximation-consistency and acceptable approximation-consistency of interval multiplicative reciprocal comparison matrices are proposed. The exchange method is designed to generate all the permutations. A novel method of determining the interval weight vector is proposed under the consideration of randomness in comparing alternatives, and a vector of interval weights is determined. A new algorithm of solving decision making problems with interval multiplicative reciprocal preference relations is provided. Two numerical examples are carried out to illustrate the proposed approach and offer a comparison with the methods available in the literature.
Granberg, Tobias; Fan, Qiuyun; Treaba, Constantina Andrada; Ouellette, Russell; Herranz, Elena; Mangeat, Gabriel; Louapre, Céline; Cohen-Adad, Julien; Klawiter, Eric C; Sloane, Jacob A; Mainero, Caterina
2017-11-01
Neuroaxonal pathology is a main determinant of disease progression in multiple sclerosis; however, its underlying pathophysiological mechanisms, including its link to inflammatory demyelination and temporal occurrence in the disease course are still unknown. We used ultra-high field (7 T), ultra-high gradient strength diffusion and T1/T2-weighted myelin-sensitive magnetic resonance imaging to characterize microstructural changes in myelin and neuroaxonal integrity in the cortex and white matter in early stage multiple sclerosis, their distribution in lesional and normal-appearing tissue, and their correlations with neurological disability. Twenty-six early stage multiple sclerosis subjects (disease duration ≤5 years) and 24 age-matched healthy controls underwent 7 T T2*-weighted imaging for cortical lesion segmentation and 3 T T1/T2-weighted myelin-sensitive imaging and neurite orientation dispersion and density imaging for assessing microstructural myelin, axonal and dendrite integrity in lesional and normal-appearing tissue of the cortex and the white matter. Conventional mean diffusivity and fractional anisotropy metrics were also assessed for comparison. Cortical lesions were identified in 92% of early multiple sclerosis subjects and they were characterized by lower intracellular volume fraction (P = 0.015 by paired t-test), lower myelin-sensitive contrast (P = 0.030 by related-samples Wilcoxon signed-rank test) and higher mean diffusivity (P = 0.022 by related-samples Wilcoxon signed-rank test) relative to the contralateral normal-appearing cortex. Similar findings were observed in white matter lesions relative to normal-appearing white matter (all P < 0.001), accompanied by an increased orientation dispersion (P < 0.001 by paired t-test) and lower fractional anisotropy (P < 0.001 by related-samples Wilcoxon signed-rank test) suggestive of less coherent underlying fibre orientation. Additionally, the normal-appearing white matter in multiple sclerosis subjects had diffusely lower intracellular volume fractions than the white matter in controls (P = 0.029 by unpaired t-test). Cortical thickness did not differ significantly between multiple sclerosis subjects and controls. Higher orientation dispersion in the left primary motor-somatosensory cortex was associated with increased Expanded Disability Status Scale scores in surface-based general linear modelling (P < 0.05). Microstructural pathology was frequent in early multiple sclerosis, and present mainly focally in cortical lesions, whereas more diffusely in white matter. These results suggest early demyelination with loss of cells and/or cell volumes in cortical and white matter lesions, with additional axonal dispersion in white matter lesions. In the cortex, focal lesion changes might precede diffuse atrophy with cortical thinning. Findings in the normal-appearing white matter reveal early axonal pathology outside inflammatory demyelinating lesions. © The Author (2017). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
Multi-scale pixel-based image fusion using multivariate empirical mode decomposition.
Rehman, Naveed ur; Ehsan, Shoaib; Abdullah, Syed Muhammad Umer; Akhtar, Muhammad Jehanzaib; Mandic, Danilo P; McDonald-Maier, Klaus D
2015-05-08
A novel scheme to perform the fusion of multiple images using the multivariate empirical mode decomposition (MEMD) algorithm is proposed. Standard multi-scale fusion techniques make a priori assumptions regarding input data, whereas standard univariate empirical mode decomposition (EMD)-based fusion techniques suffer from inherent mode mixing and mode misalignment issues, characterized respectively by either a single intrinsic mode function (IMF) containing multiple scales or the same indexed IMFs corresponding to multiple input images carrying different frequency information. We show that MEMD overcomes these problems by being fully data adaptive and by aligning common frequency scales from multiple channels, thus enabling their comparison at a pixel level and subsequent fusion at multiple data scales. We then demonstrate the potential of the proposed scheme on a large dataset of real-world multi-exposure and multi-focus images and compare the results against those obtained from standard fusion algorithms, including the principal component analysis (PCA), discrete wavelet transform (DWT) and non-subsampled contourlet transform (NCT). A variety of image fusion quality measures are employed for the objective evaluation of the proposed method. We also report the results of a hypothesis testing approach on our large image dataset to identify statistically-significant performance differences.
Multi-Scale Pixel-Based Image Fusion Using Multivariate Empirical Mode Decomposition
Rehman, Naveed ur; Ehsan, Shoaib; Abdullah, Syed Muhammad Umer; Akhtar, Muhammad Jehanzaib; Mandic, Danilo P.; McDonald-Maier, Klaus D.
2015-01-01
A novel scheme to perform the fusion of multiple images using the multivariate empirical mode decomposition (MEMD) algorithm is proposed. Standard multi-scale fusion techniques make a priori assumptions regarding input data, whereas standard univariate empirical mode decomposition (EMD)-based fusion techniques suffer from inherent mode mixing and mode misalignment issues, characterized respectively by either a single intrinsic mode function (IMF) containing multiple scales or the same indexed IMFs corresponding to multiple input images carrying different frequency information. We show that MEMD overcomes these problems by being fully data adaptive and by aligning common frequency scales from multiple channels, thus enabling their comparison at a pixel level and subsequent fusion at multiple data scales. We then demonstrate the potential of the proposed scheme on a large dataset of real-world multi-exposure and multi-focus images and compare the results against those obtained from standard fusion algorithms, including the principal component analysis (PCA), discrete wavelet transform (DWT) and non-subsampled contourlet transform (NCT). A variety of image fusion quality measures are employed for the objective evaluation of the proposed method. We also report the results of a hypothesis testing approach on our large image dataset to identify statistically-significant performance differences. PMID:26007714
Multiple high-intensity focused ultrasound probes for kidney-tissue ablation.
Häcker, Axel; Chauhan, Sunita; Peters, Kristina; Hildenbrand, Ralf; Marlinghaus, Ernst; Alken, Peter; Michel, Maurice Stephan
2005-10-01
To investigate kidney-tissue ablation by high-intensity focused ultrasound (HIFU) using multiple and single probes. Ultrasound beams (1.75 MHz) produced by a piezoceramic element (focal distance 80 mm) were focused at the center of renal parenchyma. One of the three probes (mounted on a jig) could also be used for comparison with a single probe at comparable power ratings. Lesion dimensions were examined in perfused and unperfused ex vivo porcine kidneys at different power levels (40, 60, and 80 W) and treatment times (4, 6, and 8 seconds). At identical power levels, the lesions induced by multiple probes were larger than those induced by a single probe. Lesion size increased with increasing pulse duration and generator power. The sizes and shapes of the lesions were predictably repeatable in all samples. Lesions in perfused kidneys were smaller than those in unperfused kidneys. Ex vivo, kidney-tissue ablation by means of multiple HIFU probes offers significant advantages over single HIFU probes in respect of lesion size and formation. These advantages need to be confirmed by tests in vivo at higher energy levels.
A test harness for accelerating physics parameterization advancements into operations
NASA Astrophysics Data System (ADS)
Firl, G. J.; Bernardet, L.; Harrold, M.; Henderson, J.; Wolff, J.; Zhang, M.
2017-12-01
The process of transitioning advances in parameterization of sub-grid scale processes from initial idea to implementation is often much quicker than the transition from implementation to use in an operational setting. After all, considerable work must be undertaken by operational centers to fully test, evaluate, and implement new physics. The process is complicated by the scarcity of like-to-like comparisons, availability of HPC resources, and the ``tuning problem" whereby advances in physics schemes are difficult to properly evaluate without first undertaking the expensive and time-consuming process of tuning to other schemes within a suite. To address this process shortcoming, the Global Model TestBed (GMTB), supported by the NWS NGGPS project and undertaken by the Developmental Testbed Center, has developed a physics test harness. It implements the concept of hierarchical testing, where the same code can be tested in model configurations of varying complexity from single column models (SCM) to fully coupled, cycled global simulations. Developers and users may choose at which level of complexity to engage. Several components of the physics test harness have been implemented, including a SCM and an end-to-end workflow that expands upon the one used at NOAA/EMC to run the GFS operationally, although the testbed components will necessarily morph to coincide with changes to the operational configuration (FV3-GFS). A standard, relatively user-friendly interface known as the Interoperable Physics Driver (IPD) is available for physics developers to connect their codes. This prerequisite exercise allows access to the testbed tools and removes a technical hurdle for potential inclusion into the Common Community Physics Package (CCPP). The testbed offers users the opportunity to conduct like-to-like comparisons between the operational physics suite and new development as well as among multiple developments. GMTB staff have demonstrated use of the testbed through a comparison between the 2017 operational GFS suite and one containing the Grell-Freitas convective parameterization. An overview of the physics test harness and its early use will be presented.
A comparison of the wear resistance and hardness of indirect composite resins.
Mandikos, M N; McGivney, G P; Davis, E; Bush, P J; Carter, J M
2001-04-01
Various new, second-generation indirect composites have been developed with claimed advantages over existing tooth-colored restorative materials. To date, little independent research has been published on these materials, and the properties specified in the advertising materials are largely derived from in-house or contracted testing. Four second-generation indirect composites (Artglass, belleGlass, Sculpture, and Targis) were tested for wear resistance and hardness against 2 control materials with well-documented clinical application. Human enamel was also tested for comparison. Twelve specimens of each material were fabricated according to the manufacturers' directions and subjected to accelerated wear in a 3-body abrasion, toothbrushing apparatus. Vickers hardness was measured for each of the tested materials, and energy dispersive x-ray (EDX) spectroscopy was performed to determine the elemental composition of the composite fillers. The statistical tests used for wear and hardness were the Kruskal-Wallis 1-way ANOVA test with Mann-Whitney tests and 1-way ANOVA with multiple comparisons (Tukey HSD). The Pearson correlation coefficient was used to determine the existence of a relationship between the hardness of the materials and the degree to which they had worn. The level of statistical significance chosen was alpha=.05. The control material Concept was superior to the other composites in wear resistance and hardness and had the lowest surface roughness. Significant relationships were observed between depth of wear and hardness and between depth of wear and average surface roughness. Enamel specimens were harder and more wear resistant than any of the composites. EDX spectroscopy revealed that the elemental composition of the fillers of the 4 new composites was almost identical, as was the composition of the 2 control composites. The differences in wear, hardness, and average surface roughness may have been due to differences in the chemistry or method of polymerization of the composites. Further research in this area should be encouraged. It was also apparent that the filler present in the tested composites did not exactly fit the manufacturers' descriptions.
Hosaka, Keiichi; Nakajima, Masatoshi; Monticelli, Francesca; Carrilho, Marcela; Yamauti, Monica; Aksornmuang, Juthatip; Nishitani, Yoshihiro; Tay, Franklin R; Pashley, David H; Tagami, Junji
2007-10-01
To evaluate the microtensile bond strength (microTBS) of two all-in-one self-etching adhesive systems and two self-etching adhesives with and without simulated hydrostatic pulpal pressure (PP). Flat coronal dentin surfaces of extracted human molars were prepared. Two all-in-one self-etching adhesive systems, One-Up Bond F (OBF; Tokuyama) and Clearfil S3 Bond (Tri-S, Kuraray Medical) and two self-etching primer adhesives, Clearfil Protect Bond (PB; Kuraray) and Clearfil SE Bond (SE; Kuraray) were applied to the dentin surfaces according to manufacturers' instructions under either a pulpal pressure (PP) of zero or 15 cm H2O. A hybrid resin composite (Clearfil AP-X, Kuraray) was used for the coronal buildup. Specimens bonded under PP were stored in water at 37 degrees C under 15 cm H2O for 24 h. Specimens not bonded under PP were stored under a PP of zero. After storage, the bonded specimens were sectioned into slabs that were trimmed to hourglass-shaped specimens, and were subjected to microtensile bond testing (microTBS). The bond strength data were statistically analyzed using two-way ANOVA and the Holm-Sidak method for multiple comparison tests (alpha = 0.05). The surface area percentage of different failure modes for each material was also statistically analyzed with three one-way ANOVAs and Tukey's multiple comparison tests. The microTBS of OBF and Tri-S fell significantly under PP. However, in the, PB and SE bonded specimens under PP, there were no significant differences compared with the control groups without PP. The microTBS of the two all-in-one adhesive systems decreased when PP was applied. However, the microTBS of both self-etching primer adhesives did not decrease under PP.
Hallberg, Pär; Nagy, Julia; Karawajczyk, Malgorzata; Nordang, Leif; Islander, Gunilla; Norling, Pia; Johansson, Hans-Erik; Kämpe, Mary; Hugosson, Svante; Yue, Qun-Ying; Wadelius, Mia
2017-04-01
Angioedema is a rare and serious adverse drug reaction (ADR) to angiotensin-converting enzyme (ACE) inhibitor treatment. Dry cough is a common side effect of ACE inhibitors and has been identified as a possible risk factor for angioedema. We compared characteristics between patients with ACE inhibitor-induced angioedema and cough with the aim of identifying risk factors that differ between these adverse events. Data on patients with angioedema or cough induced by ACE inhibitors were collected from the Swedish database of spontaneously reported ADRs or from collaborating clinicians. Wilcoxon rank sum test, Fisher's exact test, and odds ratios (ORs) with 95% CIs were used to test for between-group differences. The significance threshold was set to P <0.00128 to correct for multiple comparisons. Clinical characteristics were compared between 168 patients with angioedema and 121 with cough only. Smoking and concomitant selective calcium channel blocker treatment were more frequent among patients with angioedema than cough: OR = 4.3, 95% CI = 2.1-8.9, P = 2.2 × 10 -5 , and OR = 3.7, 95% CI = 2.0-7.0, P = 1.7 × 10 -5 . Angioedema cases were seen more often in male patients (OR = 2.2, 95% CI = 1.4-3.6, P = 1.3 × 10 -4 ) and had longer time to onset and higher doses than those with cough ( P = 3.2 × 10 -10 and P = 2.6 × 10 -4 ). A multiple model containing the variables smoking, concurrent calcium channel blocker treatment, male sex, and time to onset accounted for 26% of the variance between the groups. Smoking, comedication with selective calcium channel blockers, male sex, and longer treatment time were associated with ACE inhibitor-induced angioedema rather than cough.
Yelnik, A P; Tasseel Ponche, S; Andriantsifanetra, C; Provost, C; Calvalido, A; Rougier, P
2015-12-01
The Romberg test, with the subject standing and with eyes closed, gives diagnostic arguments for a proprioceptive disorder. Closing the eyes is also used in balance rehabilitation as a main way to stimulate neural plasticity with proprioceptive, vestibular and even cerebellar disorders. Nevertheless, standing and walking with eyes closed or with eyes open in the dark are certainly 2 different tasks. We aimed to compare walking with eyes open, closed and wearing black or white goggles in healthy subjects. A total of 50 healthy participants were randomly divided into 2 protocols and asked to walk on a 5-m pressure-sensitive mat, under 3 conditions: (1) eyes open (EO), eyes closed (EC) and eyes open with black goggles (BG) and (2) EO, EO with BG and with white goggles (WG). Gait was described by velocity (m·s(-1)), double support (% gait cycle), gait variability index (GVI/100) and exit from the mat (%). Analysis involved repeated measures Anova, Holm-Sidak's multiple comparisons test for parametric parameters (GVI) and Dunn's multiple comparisons test for non-parametric parameters. As compared with walking with EC, walking with BG produced lower median velocity, by 6% (EO 1.26; BG 1.01 vs EC 1.07 m·s(-1), P=0.0328), and lower mean GVI, by 8% (EO 91.8; BG 66.8 vs EC 72.24, P=0.009). Parameters did not differ between walking under the BG and WG conditions. The goggle task increases the difficulty in walking with visual deprivation compared to the Romberg task, so the goggle task can be proposed to gradually increase the difficulty in walking with visual deprivation (from eyes closed to eyes open in black goggles). Copyright © 2015 Elsevier Masson SAS. All rights reserved.
NASA Technical Reports Server (NTRS)
Arnold, S. M.; Saleeb, A. F.
2003-01-01
Given the previous complete-potential structure framework together with the notion of strain- and stress-partitioning in terms of separate contributions of several submechanisms (viscoelastic and viscoplastic) to the thermodynamic functions (stored energy and dissipation) a detailed viscoelastoplastic multimechanism characterization of a specific hardening functional form of the model is presented and discussed. TIMETAL 21S is the material of choice as a comprehensive test matrix, including creep, relaxation, constant strain-rate tension tests, etc. are available at various temperatures. Discussion of these correlations tests, together with comparisons to several other experimental results, are given to assess the performance and predictive capabilities of the present model particularly with regard to the notion of hardening saturation as well as the interaction of multiplicity of dissipative (reversible/irreversible) mechanisms.
NASA Technical Reports Server (NTRS)
Haynes, Jared; Kenny, R. Jeremy
2010-01-01
Recently, members of the Marshall Space Flight Center (MSFC) Fluid Dynamics Branch and Wyle Labs measured far-field acoustic data during a series of three Reusable Solid Rocket Motor (RSRM) horizontal static tests conducted in Promontory, Utah. The test motors included the Technical Evaluation Motor 13 (TEM-13), Flight Verification Motor 2 (FVM-2), and the Flight Simulation Motor 15 (FSM-15). Similar far-field data were collected during horizontal static tests of sub-scale solid rocket motors at MSFC. Far-field acoustical measurements were taken at multiple angles within a circular array centered about the nozzle exit plane, each positioned at a radial distance of 80 nozzle-exit-diameters from the nozzle. This type of measurement configuration is useful for calculating rocket noise characteristics such as those outlined in the NASA SP-8072 "Acoustic Loads Generated by the Propulsion System." Acoustical scaling comparisons are made between the test motors, with particular interest in the Overall Sound Power, Acoustic Efficiency, Non-dimensional Relative Sound Power Spectrum, and Directivity. Since most empirical data in the NASA SP-8072 methodology is derived from small rockets, this investigation provides an opportunity to check the data collapse between a sub-scale and full-scale rocket motor.
An Interlaboratory Comparison of Dosimetry for a Multi-institutional Radiobiological
Seed, TM; Xiao, S; Manley, N; Nikolich-Zugich, J; Pugh, J; van den Brink, M; Hirabayashi, Y; Yasutomo, K; Iwama, A; Koyasu, S; Shterev, I; Sempowski, G; Macchiarini, F; Nakachi, K; Kunugi, KC; Hammer, CG; DeWerd, LA
2016-01-01
Purpose An interlaboratory comparison of radiation dosimetry was conducted to determine the accuracy of doses being used experimentally for animal exposures within a large multi-institutional research project. The background and approach to this effort are described and discussed in terms of basic findings, problems and solutions. Methods Dosimetry tests were carried out utilizing optically stimulated luminescence (OSL) dosimeters embedded midline into mouse carcasses and thermal luminescence dosimeters (TLD) embedded midline into acrylic phantoms. Results The effort demonstrated that the majority (4/7) of the laboratories was able to deliver sufficiently accurate exposures having maximum dosing errors of ≤ 5%. Comparable rates of ‘dosimetric compliance’ were noted between OSL- and TLD-based tests. Data analysis showed a highly linear relationship between ‘measured’ and ‘target’ doses, with errors falling largely between 0–20%. Outliers were most notable for OSL-based tests, while multiple tests by ‘non-compliant’ laboratories using orthovoltage x-rays contributed heavily to the wide variation in dosing errors. Conclusions For the dosimetrically non-compliant laboratories, the relatively high rates of dosing errors were problematic, potentially compromising the quality of ongoing radiobiological research. This dosimetry effort proved to be instructive in establishing rigorous reviews of basic dosimetry protocols ensuring that dosing errors were minimized. PMID:26857121
Seed, Thomas M; Xiao, Shiyun; Manley, Nancy; Nikolich-Zugich, Janko; Pugh, Jason; Van den Brink, Marcel; Hirabayashi, Yoko; Yasutomo, Koji; Iwama, Atsushi; Koyasu, Shigeo; Shterev, Ivo; Sempowski, Gregory; Macchiarini, Francesca; Nakachi, Kei; Kunugi, Keith C; Hammer, Clifford G; Dewerd, Lawrence A
2016-01-01
An interlaboratory comparison of radiation dosimetry was conducted to determine the accuracy of doses being used experimentally for animal exposures within a large multi-institutional research project. The background and approach to this effort are described and discussed in terms of basic findings, problems and solutions. Dosimetry tests were carried out utilizing optically stimulated luminescence (OSL) dosimeters embedded midline into mouse carcasses and thermal luminescence dosimeters (TLD) embedded midline into acrylic phantoms. The effort demonstrated that the majority (4/7) of the laboratories was able to deliver sufficiently accurate exposures having maximum dosing errors of ≤5%. Comparable rates of 'dosimetric compliance' were noted between OSL- and TLD-based tests. Data analysis showed a highly linear relationship between 'measured' and 'target' doses, with errors falling largely between 0 and 20%. Outliers were most notable for OSL-based tests, while multiple tests by 'non-compliant' laboratories using orthovoltage X-rays contributed heavily to the wide variation in dosing errors. For the dosimetrically non-compliant laboratories, the relatively high rates of dosing errors were problematic, potentially compromising the quality of ongoing radiobiological research. This dosimetry effort proved to be instructive in establishing rigorous reviews of basic dosimetry protocols ensuring that dosing errors were minimized.
Race and gender discrimination in the Marines.
Foynes, Melissa Ming; Shipherd, Jillian C; Harrington, Ellen F
2013-01-01
Although women of color have been hypothesized to experience double jeopardy in the form of chronic exposure to both race-based (RBD) and gender-based discrimination (GBD; Beal, 1970), few empirical investigations that examine both RBD and GBD in multiple comparison groups have been conducted. In addition to being one of the only simultaneous examinations of RBD and GBD in multiple comparison groups, the current study includes both self-report and objective behavioral data to examine the independent and interactive effects of both forms of discrimination. This study is also the first of its kind to examine these constructs in these ways and to explore their impact in a unique sample of ethnically diverse male and female Marine recruits (N = 1,516). As anticipated, both RBD and GBD had a strong and consistent negative impact on mental health symptoms (e.g., depression, anxiety), independent of the contributions of gender and race. Partial support was found for the hypothesis that people of color are able to maintain resiliency (as measured by physical fitness testing) in the face of low levels of RBD, but are less able to overcome the negative effects of discrimination at high levels. It is interesting to note that the interaction between race, gender, and levels of discrimination was only found with objective physical fitness test scores but not with self-report measures. These findings underscore the importance of including objective measures when assessing the impact of discrimination in order to understand these complex interrelationships.
An adaptive two-stage dose-response design method for establishing proof of concept.
Franchetti, Yoko; Anderson, Stewart J; Sampson, Allan R
2013-01-01
We propose an adaptive two-stage dose-response design where a prespecified adaptation rule is used to add and/or drop treatment arms between the stages. We extend the multiple comparison procedures-modeling (MCP-Mod) approach into a two-stage design. In each stage, we use the same set of candidate dose-response models and test for a dose-response relationship or proof of concept (PoC) via model-associated statistics. The stage-wise test results are then combined to establish "global" PoC using a conditional error function. Our simulation studies showed good and more robust power in our design method compared to conventional and fixed designs.
Analysis of brief language tests in the detection of cognitive decline and dementia
Radanovic, Marcia; Carthery-Goulart, Maria Teresa; Charchat-Fichman, Helenice; Herrera Jr., Emílio; Lima, Edson Erasmo Pereira; Smid, Jerusa; Porto, Cláudia Sellitto; Nitrini, Ricardo
2007-01-01
Lexical access difficulties are frequent in normal aging and initial stages of dementia.Verbal fluency tests are valuable to detect cognitive decline, evidencing lexico-semantic and executive dysfunction. Objectives To establish which language tests can contribute in detecting dementia and to verify schooling influence on subject performance. Method 74 subjects: 33 controls, 17 Clinical Dementia Rating (CDR) 0.5 and 24 (Brief Cognitive Battery - BCB e Boston Naming Test - BNT) 1 were compared in tests of semantic verbal fluency (animal and fruit), picture naming (BCB and BNT) and the language items of Mini Mental State Examination (MMSE). Results There were significant differences between the control group and both CDR 0.5 and CDR 1 in all tests. Cut-off scores were: 11 and 10 for animal fluency, 8 for fruit fluency (in both), 8 and 9 for BCB naming. The CDR 0.5 group performed better than the CDR 1 group only in animal fluency. Stepwise multiple regression revealed fruit fluency, animal fluency and BCB naming as the best discriminators between patients and controls (specificity: 93.8%; sensitivity: 91.3%). In controls, comparison between illiterates and literates evidenced schooling influence in all tests, except for fruit fluency and BCB naming. In patients with dementia, only fruit fluency was uninfluenced by schooling. Conclusion The combination of verbal fluency tests in two semantic categories along with a simple picture naming test is highly sensitive in detecting cognitive decline. Comparison between literate and illiterate subjects shows a lesser degree of influence of schooling on the selected tests, thus improving discrimination between low performance and incipient cognitive decline. PMID:29213366
Power calculation for overall hypothesis testing with high-dimensional commensurate outcomes.
Chi, Yueh-Yun; Gribbin, Matthew J; Johnson, Jacqueline L; Muller, Keith E
2014-02-28
The complexity of system biology means that any metabolic, genetic, or proteomic pathway typically includes so many components (e.g., molecules) that statistical methods specialized for overall testing of high-dimensional and commensurate outcomes are required. While many overall tests have been proposed, very few have power and sample size methods. We develop accurate power and sample size methods and software to facilitate study planning for high-dimensional pathway analysis. With an account of any complex correlation structure between high-dimensional outcomes, the new methods allow power calculation even when the sample size is less than the number of variables. We derive the exact (finite-sample) and approximate non-null distributions of the 'univariate' approach to repeated measures test statistic, as well as power-equivalent scenarios useful to generalize our numerical evaluations. Extensive simulations of group comparisons support the accuracy of the approximations even when the ratio of number of variables to sample size is large. We derive a minimum set of constants and parameters sufficient and practical for power calculation. Using the new methods and specifying the minimum set to determine power for a study of metabolic consequences of vitamin B6 deficiency helps illustrate the practical value of the new results. Free software implementing the power and sample size methods applies to a wide range of designs, including one group pre-intervention and post-intervention comparisons, multiple parallel group comparisons with one-way or factorial designs, and the adjustment and evaluation of covariate effects. Copyright © 2013 John Wiley & Sons, Ltd.
Psychological, neuropsychological, and electrocortical effects of mixed mold exposure.
Crago, B Robert; Gray, Michael R; Nelson, Lonnie A; Davis, Marilyn; Arnold, Linda; Thrasher, Jack D
2003-08-01
The authors assessed the psychological, neuropsychological, and electrocortical effects of human exposure to mixed colonies of toxigenic molds. Patients (N = 182) with confirmed mold-exposure history completed clinical interviews, a symptom checklist (SCL-90-R), limited neuropsychological testing, quantitative electroencephalogram (QEEG) with neurometric analysis, and measures of mold exposure. Patients reported high levels of physical, cognitive, and emotional symptoms. Ratings on the SCL-90-R were "moderate" to "severe," with a factor reflecting situational depression accounting for most of the variance. Most of the patients were found to suffer from acute stress, adjustment disorder, or post-traumatic stress. Differential diagnosis confirmed an etiology of a combination of external stressors, along with organic metabolically based dysregulation of emotions and decreased cognitive functioning as a result of toxic or metabolic encephalopathy. Measures of toxic mold exposure predicted QEEG measures and neuropsychological test performance. QEEG results included narrowed frequency bands and increased power in the alpha and theta bands in the frontal areas of the cortex. These findings indicated a hypoactivation of the frontal cortex, possibly due to brainstem involvement and insufficient excitatory input from the reticular activating system. Neuropsychological testing revealed impairments similar to mild traumatic brain injury. In comparison with premorbid estimates of intelligence, findings of impaired functioning on multiple cognitive tasks predominated. A dose-response relationship between measures of mold exposure and abnormal neuropsychological test results and QEEG measures suggested that toxic mold causes significant problems in exposed individuals. Study limitations included lack of a comparison group, patient selection bias, and incomplete data sets that did not allow for comparisons among variables.
Variance-based selection may explain general mating patterns in social insects.
Rueppell, Olav; Johnson, Nels; Rychtár, Jan
2008-06-23
Female mating frequency is one of the key parameters of social insect evolution. Several hypotheses have been suggested to explain multiple mating and considerable empirical research has led to conflicting results. Building on several earlier analyses, we present a simple general model that links the number of queen matings to variance in colony performance and this variance to average colony fitness. The model predicts selection for multiple mating if the average colony succeeds in a focal task, and selection for single mating if the average colony fails, irrespective of the proximate mechanism that links genetic diversity to colony fitness. Empirical support comes from interspecific comparisons, e.g. between the bee genera Apis and Bombus, and from data on several ant species, but more comprehensive empirical tests are needed.
Kunz, Jennifer Hauser; Hommel, Kevin A; Greenley, Rachel Neff
2010-06-01
This study compared youth and parent-proxy reports of health-related quality of life (HRQoL) among youth with inflammatory bowel disease (IBD) to published comparison group data and examined concordance between youth and parent-proxy reports of HRQoL. One hundred thirty-six youth and parent-proxy reports on the PedsQL 4.0 Generic Core Scales were compared to published data from chronically ill, acutely ill, and healthy comparison groups using independent samples t-tests. Reporter agreement was examined using paired samples t-tests and intraclass correlations (ICCs). Youth with IBD reported lower psychosocial functioning than the healthy comparison group, higher physical and social functioning than the chronically ill group, and lower school functioning than all published comparison groups. Parent-proxy reports of youth HRQoL were higher than the chronically ill group, but lower than the healthy group on all scales except psychosocial functioning. Youth with active IBD reported lower physical health domain scores than youth with inactive disease. Concordance between youth and parent-proxy reports was moderate, with the lowest agreement in school and social functioning. Youth with IBD and their parents rate HRQoL as lower than healthy youth but do not perceive the impact of IBD to be as limiting as in other chronic conditions. Youth report suggests that IBD may be particularly detrimental to HRQoL in the school functioning domain. Moderate agreement between parent and youth reports substantiates continued use of multiple informants in studies of pediatric HRQoL.
On Two-Stage Multiple Comparison Procedures When There Are Unequal Sample Sizes in the First Stage.
ERIC Educational Resources Information Center
Wilcox, Rand R.
1984-01-01
Two stage multiple-comparison procedures give an exact solution to problems of power and Type I errors, but require equal sample sizes in the first stage. This paper suggests a method of evaluating the experimentwise Type I error probability when the first stage has unequal sample sizes. (Author/BW)
Pairwise Multiple Comparisons in Single Group Repeated Measures Analysis.
ERIC Educational Resources Information Center
Barcikowski, Robert S.; Elliott, Ronald S.
Research was conducted to provide educational researchers with a choice of pairwise multiple comparison procedures (P-MCPs) to use with single group repeated measures designs. The following were studied through two Monte Carlo (MC) simulations: (1) The T procedure of J. W. Tukey (1953); (2) a modification of Tukey's T (G. Keppel, 1973); (3) the…
Dong, Runze; Pan, Shuo; Peng, Zhenling; Zhang, Yang; Yang, Jianyi
2018-05-21
With the rapid increase of the number of protein structures in the Protein Data Bank, it becomes urgent to develop algorithms for efficient protein structure comparisons. In this article, we present the mTM-align server, which consists of two closely related modules: one for structure database search and the other for multiple structure alignment. The database search is speeded up based on a heuristic algorithm and a hierarchical organization of the structures in the database. The multiple structure alignment is performed using the recently developed algorithm mTM-align. Benchmark tests demonstrate that our algorithms outperform other peering methods for both modules, in terms of speed and accuracy. One of the unique features for the server is the interplay between database search and multiple structure alignment. The server provides service not only for performing fast database search, but also for making accurate multiple structure alignment with the structures found by the search. For the database search, it takes about 2-5 min for a structure of a medium size (∼300 residues). For the multiple structure alignment, it takes a few seconds for ∼10 structures of medium sizes. The server is freely available at: http://yanglab.nankai.edu.cn/mTM-align/.
Positional Role Differences in the Aerobic and Anaerobic Power of Elite Basketball Players.
Pojskić, Haris; Šeparović, Vlatko; Užičanin, Edin; Muratović, Melika; Mačković, Samir
2015-12-22
The aim of the present study was to compare the aerobic and anaerobic power and capacity of elite male basketball players who played multiple positions. Fifty-five healthy players were divided into the following three different subsamples according to their positional role: guards (n = 22), forwards (n = 19) and centers (n = 14). The following three tests were applied to estimate their aerobic and anaerobic power and capacities: the countermovement jump (CMJ), a multistage shuttle run test and the Running-based Anaerobic Sprint Test (RAST). The obtained data were used to calculate the players' aerobic and anaerobic power and capacities. To determine the possible differences between the subjects considering their different positions on the court, one-way analysis of variance (ANOVA) with the Bonferroni post-hoc test for multiple comparisons was used. The results showed that there was a significant difference between the different groups of players in eleven out of sixteen measured variables. Guards and forwards exhibited greater aerobic and relative values of anaerobic power, allowing shorter recovery times and the ability to repeat high intensity, basketball-specific activities. Centers presented greater values of absolute anaerobic power and capacities, permitting greater force production during discrete tasks. Coaches can use these data to create more individualized strength and conditioning programs for different positional roles.
Teklu, Berhan M; Retta, Negussie; Van den Brink, Paul J
2016-08-01
The aims of the present study were to present a methodology for toxicity tests that can be used when analytical resources to verify the test concentrations are limited, and to evaluate whether the sensitivity of a limited number of Ethiopian species to pesticides differs from literature values for, mainly, temperate species. Acute toxicity tests were performed using three Ethiopian aquatic invertebrate species, one crustacean (Diaphanosoma brachyurum) and two insects (Anopheles pharoensis and Culex pipiens) and using the pesticides endosulfan and diazinon. All species-pesticide combinations were tested in duplicate to estimate the consistency, i.e. the intra-laboratory variation, in test results. Daphnia magna was tested as well to allow the test results to be compared directly with values from the literature. Results indicate that the differences between the EC50s obtained for D. magna in this study and those reported in the literature were less than a factor of 2. This indicates that the methodology used is able to provide credible toxicity values. The results of the duplicated tests showed intra-laboratory variation in EC50 values of up to a factor of 3, with one test showing a difference of a factor of 6 at 48 h. Comparison with available literature results for arthropod species using species sensitivity distributions indicated that the test results obtained in this study fit well in the log-normal distribution of the literature values. We conclude that the methodology of performing multiple tests to check for consistency of test results and performing tests with D. magna for comparison with literature values to check for accuracy is able to provide reliable effect threshold levels and that the tested Ethiopian species did not differ in sensitivity from the arthropod species reported on in the literature.
Abe Silverstein 10- by 10-Foot Supersonic Wind Tunnel Validated for Low-Speed (Subsonic) Operation
NASA Technical Reports Server (NTRS)
Hoffman, Thomas R.
2001-01-01
The NASA Glenn Research Center and Lockheed Martin Corporation tested an aircraft model in two wind tunnels to compare low-speed (subsonic) flow characteristics. Objectives of the test were to determine and document the similarities and uniqueness of the tunnels and to validate that Glenn's 10- by 10-Foot Supersonic Wind Tunnel (10x10 SWT) is a viable low-speed test facility. Results from two of Glenn's wind tunnels compare very favorably and show that the 10x10 SWT is a viable low-speed wind tunnel. The Subsonic Comparison Test was a joint effort by NASA and Lockheed Martin using the Lockheed Martin's Joint Strike Fighter Concept Demonstration Aircraft model. Although Glenn's 10310 and 836 SWT's have many similarities, they also have unique characteristics. Therefore, test data were collected for multiple model configurations at various vertical locations in the test section, starting at the test section centerline and extending into the ceiling and floor boundary layers.
Binding of multiple features in memory by high-functioning adults with autism spectrum disorder.
Bowler, Dermot M; Gaigg, Sebastian B; Gardiner, John M
2014-09-01
Diminished episodic memory and diminished use of semantic information to aid recall by individuals with autism spectrum disorder (ASD) are both thought to result from diminished relational binding of elements of complex stimuli. To test this hypothesis, we asked high-functioning adults with ASD and typical comparison participants to study grids in which some cells contained drawings of objects in non-canonical colours. Participants were told at study which features (colour, item, location) would be tested in a later memory test. In a second experiment, participants studied similar grids and were told that they would be tested on object-location or object-colour combinations. Recognition of combinations was significantly diminished in ASD, which survived covarying performance on the Color Trails Test (D'Elia et al. Color trails test. Professional manual. Psychological Assessment Resources, Lutz, 1996), a test of executive difficulties. The findings raise the possibility that medial temporal as well as frontal lobe processes are dysfunctional in ASD.
Pallmann, Philip; Schaarschmidt, Frank; Hothorn, Ludwig A; Fischer, Christiane; Nacke, Heiko; Priesnitz, Kai U; Schork, Nicholas J
2012-11-01
Comparing diversities between groups is a task biologists are frequently faced with, for example in ecological field trials or when dealing with metagenomics data. However, researchers often waver about which measure of diversity to choose as there is a multitude of approaches available. As Jost (2008, Molecular Ecology, 17, 4015) has pointed out, widely used measures such as the Shannon or Simpson index have undesirable properties which make them hard to compare and interpret. Many of the problems associated with the use of these 'raw' indices can be corrected by transforming them into 'true' diversity measures. We introduce a technique that allows the comparison of two or more groups of observations and simultaneously tests a user-defined selection of a number of 'true' diversity measures. This procedure yields multiplicity-adjusted P-values according to the method of Westfall and Young (1993, Resampling-Based Multiple Testing: Examples and Methods for p-Value Adjustment, 49, 941), which ensures that the rate of false positives (type I error) does not rise when the number of groups and/or diversity indices is extended. Software is available in the R package 'simboot'. © 2012 Blackwell Publishing Ltd.
A Unified Framework for Association Analysis with Multiple Related Phenotypes
Stephens, Matthew
2013-01-01
We consider the problem of assessing associations between multiple related outcome variables, and a single explanatory variable of interest. This problem arises in many settings, including genetic association studies, where the explanatory variable is genotype at a genetic variant. We outline a framework for conducting this type of analysis, based on Bayesian model comparison and model averaging for multivariate regressions. This framework unifies several common approaches to this problem, and includes both standard univariate and standard multivariate association tests as special cases. The framework also unifies the problems of testing for associations and explaining associations – that is, identifying which outcome variables are associated with genotype. This provides an alternative to the usual, but conceptually unsatisfying, approach of resorting to univariate tests when explaining and interpreting significant multivariate findings. The method is computationally tractable genome-wide for modest numbers of phenotypes (e.g. 5–10), and can be applied to summary data, without access to raw genotype and phenotype data. We illustrate the methods on both simulated examples, and to a genome-wide association study of blood lipid traits where we identify 18 potential novel genetic associations that were not identified by univariate analyses of the same data. PMID:23861737
Gene discovery by chemical mutagenesis and whole-genome sequencing in Dictyostelium.
Li, Cheng-Lin Frank; Santhanam, Balaji; Webb, Amanda Nicole; Zupan, Blaž; Shaulsky, Gad
2016-09-01
Whole-genome sequencing is a useful approach for identification of chemical-induced lesions, but previous applications involved tedious genetic mapping to pinpoint the causative mutations. We propose that saturation mutagenesis under low mutagenic loads, followed by whole-genome sequencing, should allow direct implication of genes by identifying multiple independent alleles of each relevant gene. We tested the hypothesis by performing three genetic screens with chemical mutagenesis in the social soil amoeba Dictyostelium discoideum Through genome sequencing, we successfully identified mutant genes with multiple alleles in near-saturation screens, including resistance to intense illumination and strong suppressors of defects in an allorecognition pathway. We tested the causality of the mutations by comparison to published data and by direct complementation tests, finding both dominant and recessive causative mutations. Therefore, our strategy provides a cost- and time-efficient approach to gene discovery by integrating chemical mutagenesis and whole-genome sequencing. The method should be applicable to many microbial systems, and it is expected to revolutionize the field of functional genomics in Dictyostelium by greatly expanding the mutation spectrum relative to other common mutagenesis methods. © 2016 Li et al.; Published by Cold Spring Harbor Laboratory Press.
Kubsik, Anna; Klimkiewicz, Paulina; Klimkiewicz, Robert; Jankowska, Katarzyna; Jankowska, Agnieszka; Woldańska-Okońska, Marta
2014-07-01
Multiple sclerosis is a chronic, inflammatory, demyelinating disease of the central nervous system, which is characterized by diverse symptomatology. Most often affects people at a young age gradually leading to their disability. Looking for new therapies to alleviate neurological deficits caused by the disease. One of the alternative methods of therapy is high - tone power therapy. The article is a comparison of high-tone power therapy and kinesis in improving patients with multiple sclerosis. The aim of this study was to evaluate the effectiveness of high-tone power therapy and exercises in kinesis on the functional status of patients with multiple sclerosis. The study involved 20 patients with multiple sclerosis, both sexes, treated at the Department of Rehabilitation and Physical Medicine in Lodz. Patients were randomly divided into two groups studied. In group high-tone power therapy applied for 60 minutes, while in group II were used exercises for kinesis. Treatment time for both groups of patients was 15 days. To assess the functional status scale was used: Expanded Disability Status Scale of Kurtzke (EDSS), as well as by Barthel ADL Index. Assessment of quality of life were made using MSQOL Questionnaire-54. For the evaluation of gait and balance using Tinetti scale, and pain VAS rated, and Laitinen. Changes in muscle tone was assessed on the basis of the Ashworth scale. Both group I and II improved on scales conducted before and after therapy. In group I, in which the applied high-tone power therapy, reported statistically significant results in 9 out of 10 tested parameters, while in group II, which was used in the exercises in kinesis an improvement in 6 out of 10 tested parameters. Correlating the results of both the test groups in relation to each other did not show statistically significant differences. High-Tone Power Therapy beneficial effect on the functional status of patients with multiple sclerosis. Obtaining results in terms of number of tested parameters allows for the use of this therapy in the comprehensive improvement of patients with multiple sclerosis. Exercises from the scheme kinesis favorable impact on the functional status of patients with MS and are essential in the rehabilitation of these patients. In any group, no adverse effects were observed.
Standard setting: comparison of two methods.
George, Sanju; Haque, M Sayeed; Oyebode, Femi
2006-09-14
The outcome of assessments is determined by the standard-setting method used. There is a wide range of standard-setting methods and the two used most extensively in undergraduate medical education in the UK are the norm-reference and the criterion-reference methods. The aims of the study were to compare these two standard-setting methods for a multiple-choice question examination and to estimate the test-retest and inter-rater reliability of the modified Angoff method. The norm-reference method of standard-setting (mean minus 1 SD) was applied to the 'raw' scores of 78 4th-year medical students on a multiple-choice examination (MCQ). Two panels of raters also set the standard using the modified Angoff method for the same multiple-choice question paper on two occasions (6 months apart). We compared the pass/fail rates derived from the norm reference and the Angoff methods and also assessed the test-retest and inter-rater reliability of the modified Angoff method. The pass rate with the norm-reference method was 85% (66/78) and that by the Angoff method was 100% (78 out of 78). The percentage agreement between Angoff method and norm-reference was 78% (95% CI 69% - 87%). The modified Angoff method had an inter-rater reliability of 0.81-0.82 and a test-retest reliability of 0.59-0.74. There were significant differences in the outcomes of these two standard-setting methods, as shown by the difference in the proportion of candidates that passed and failed the assessment. The modified Angoff method was found to have good inter-rater reliability and moderate test-retest reliability.
Rationality in collective decision-making by ant colonies.
Edwards, Susan C; Pratt, Stephen C
2009-10-22
Economic models of animal behaviour assume that decision-makers are rational, meaning that they assess options according to intrinsic fitness value and not by comparison with available alternatives. This expectation is frequently violated, but the significance of irrational behaviour remains controversial. One possibility is that irrationality arises from cognitive constraints that necessitate short cuts like comparative evaluation. If so, the study of whether and when irrationality occurs can illuminate cognitive mechanisms. We applied this logic in a novel setting: the collective decisions of insect societies. We tested for irrationality in colonies of Temnothorax ants choosing between two nest sites that varied in multiple attributes, such that neither site was clearly superior. In similar situations, individual animals show irrational changes in preference when a third relatively unattractive option is introduced. In contrast, we found no such effect in colonies. We suggest that immunity to irrationality in this case may result from the ants' decentralized decision mechanism. A colony's choice does not depend on site comparison by individuals, but instead self-organizes from the interactions of multiple ants, most of which are aware of only a single site. This strategy may filter out comparative effects, preventing systematic errors that would otherwise arise from the cognitive limitations of individuals.
Vertical decomposition with Genetic Algorithm for Multiple Sequence Alignment
2011-01-01
Background Many Bioinformatics studies begin with a multiple sequence alignment as the foundation for their research. This is because multiple sequence alignment can be a useful technique for studying molecular evolution and analyzing sequence structure relationships. Results In this paper, we have proposed a Vertical Decomposition with Genetic Algorithm (VDGA) for Multiple Sequence Alignment (MSA). In VDGA, we divide the sequences vertically into two or more subsequences, and then solve them individually using a guide tree approach. Finally, we combine all the subsequences to generate a new multiple sequence alignment. This technique is applied on the solutions of the initial generation and of each child generation within VDGA. We have used two mechanisms to generate an initial population in this research: the first mechanism is to generate guide trees with randomly selected sequences and the second is shuffling the sequences inside such trees. Two different genetic operators have been implemented with VDGA. To test the performance of our algorithm, we have compared it with existing well-known methods, namely PRRP, CLUSTALX, DIALIGN, HMMT, SB_PIMA, ML_PIMA, MULTALIGN, and PILEUP8, and also other methods, based on Genetic Algorithms (GA), such as SAGA, MSA-GA and RBT-GA, by solving a number of benchmark datasets from BAliBase 2.0. Conclusions The experimental results showed that the VDGA with three vertical divisions was the most successful variant for most of the test cases in comparison to other divisions considered with VDGA. The experimental results also confirmed that VDGA outperformed the other methods considered in this research. PMID:21867510
DOE Office of Scientific and Technical Information (OSTI.GOV)
Mihailidis, D; Mallah, J; Zhu, D
2016-06-15
Purpose: The dosimetric leaf gap (DLG) is an important parameter to be measured for dynamic beam delivery of modern linacs, like the Varian Truebeam (TB). The clinical effects of DLG-values on IMRT and/or VMAT commissioning of two “matched” TB linacs will be presented.Methods and Materials: The DLG values on two TB linacs were measured for all energy modalities (filtered and FFF-modes) as part of the dynamic delivery mode commissioning (IMRT and/or VMAT. After the standard beam data was modeled in eclipse treatment planning system (TPS) and validated, IMRT validation was performed based on TG1191 benchmark, IROC Head-Neck (H&N) phantom andmore » sample of clinical cases, all measured on both linacs. Although there was a single-set of data entered in the TPS, a noticeable difference was observed for the DLG-values between the linacs. The TG119, IROC phantom and selected patient plans were furnished with DLG-values of TB1 for both linacs and the delivery was performed on both TB linacs for comparison. Results: The DLG values of TB1 was first used for both linacs to perform the testing comparisons. The QA comparison of TG119 plans revealed a great dependence of the results to the DLG-values used for the linac for all energy modalities studied, especially when moving from 3%/3mm to 2%/2mm γ-analysis. Conclusion: The DLG-values have a definite influence on the dynamic dose, delivery that increases with the plan complexity. We recommend that the measured DLG-values are assigned to each of the “matched” linacs, even if a single set of beam data describes multiple linacs. The user should perform a detail test of the dynamic delivery of each linac based on end-to-end benchmark suites like TG119 and IROC phantoms.1Ezzel G., et al., “IMRT commissioning: Multiple institution planning and dosimetry comparisons, a report from AAPM Task Group 119.” Med. Phys. 36:5359–5373 (2009). partly supported by CAMC Cancer Center and Alliance Oncology.« less
Resistance of superhydrophobic and oleophobic surfaces to varied temperature applications on 316L SS
NASA Astrophysics Data System (ADS)
Shams, Hamza; Basit, Kanza; Saleem, Sajid; Siddiqui, Bilal A.
316L SS also called Marine Stainless Steel is an important material for structural and marine applications. When superhydrophobic and oleophobic coatings are applied on 316L SS it shows significant resistance to wear and corrosion. This paper aims to validate the coatings manufacturer's information on optimal temperature range and test the viability of coating against multiple oil based cleaning agents. 316L SS was coated with multiple superhydrophic and oleohobic coatings and observed under SEM for validity of adhesion and thickness and then scanned under FFM to validate the tribological information. The samples were then dipped into multiple cleaning agents maintained at the range of operating temperatures specified by the manufacturer. Coating was observed for deterioration over a fixed time intervals through SEM and FFM. A comparison was drawn to validate the most critical cleaning agent and the most critical temperature at which the coating fails to leave the base substrate exposed to the environment.
NASA Technical Reports Server (NTRS)
Stahara, S. S.; Elliott, J. P.; Spreiter, J. R.
1983-01-01
An investigation was conducted to continue the development of perturbation procedures and associated computational codes for rapidly determining approximations to nonlinear flow solutions, with the purpose of establishing a method for minimizing computational requirements associated with parametric design studies of transonic flows in turbomachines. The results reported here concern the extension of the previously developed successful method for single parameter perturbations to simultaneous multiple-parameter perturbations, and the preliminary application of the multiple-parameter procedure in combination with an optimization method to blade design/optimization problem. In order to provide as severe a test as possible of the method, attention is focused in particular on transonic flows which are highly supercritical. Flows past both isolated blades and compressor cascades, involving simultaneous changes in both flow and geometric parameters, are considered. Comparisons with the corresponding exact nonlinear solutions display remarkable accuracy and range of validity, in direct correspondence with previous results for single-parameter perturbations.
Negriff, Sonya; Brensilver, Matthew; Trickett, Penelope K
2015-06-01
To test models linking pubertal timing, peer substance use, sexual behavior, and substance use for maltreated versus comparison adolescents. Three theoretical mechanisms were tested: (1) peer influence links early pubertal timing to later sexual behavior and substance use; (2) early maturers engage in substance use on their own and then select substance-using friends; or (3) early maturers initiate sexual behaviors which lead them to substance-using peers. The data came from a longitudinal study of the effects of child maltreatment on adolescent development (303 maltreated and 151 comparison adolescents; age, 9-13 years at initial wave). Multiple-group structural equation models tested the hypotheses across three time points including variables of pubertal timing, perception of peer substance use, sexual behavior, and self-reported substance use. Early pubertal timing was associated with substance-using peers only for maltreated adolescents, indicating the mediation path from early pubertal timing through substance-using peers to subsequent adolescent substance use and sexual behavior only holds for maltreated adolescents. Mediation via sexual behavior was significant for both maltreated and comparison adolescents. This indicates that sexual behavior may be a more universal mechanism linking early maturation with risky friends regardless of adverse life experiences. The findings are a step toward elucidating the developmental pathways from early puberty to risk behavior and identifying early experiences that may alter mediation effects. Copyright © 2015 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.
Perception of midline deviations in smile esthetics by laypersons.
Ferreira, Jamille Barros; Silva, Licínio Esmeraldo da; Caetano, Márcia Tereza de Oliveira; Motta, Andrea Fonseca Jardim da; Cury-Saramago, Adriana de Alcantara; Mucha, José Nelson
2016-01-01
To evaluate the esthetic perception of upper dental midline deviation by laypersons and if adjacent structures influence their judgment. An album with 12 randomly distributed frontal view photographs of the smile of a woman with the midline digitally deviated was evaluated by 95 laypersons. The frontal view smiling photograph was modified to create from 1 mm to 5 mm deviations in the upper midline to the left side. The photographs were cropped in two different manners and divided into two groups of six photographs each: group LCN included the lips, chin, and two-thirds of the nose, and group L included the lips only. The laypersons performed the rate of each smile using a visual analog scale (VAS). Wilcoxon test, Student's t-test and Mann-Whitney test were applied, adopting a 5% level of significance. Laypersons were able to perceive midline deviations starting at 1 mm. Statistically significant results (p< 0.05) were found for all multiple comparisons of the values in photographs of group LCN and for almost all comparisons in photographs of group L. Comparisons between the photographs of groups LCN and L showed statistically significant values (p< 0.05) when the deviation was 1 mm. Laypersons were able to perceive the upper dental midline deviations of 1 mm, and above when the adjacent structures of the smiles were included. Deviations of 2 mm and above when the lips only were included. The visualization of structures adjacent to the smile demonstrated influence on the perception of midline deviation.
Caponnetto, Pasquale; Polosa, Riccardo; Auditore, Roberta; Minutolo, Giuseppe; Signorelli, Maria; Maglia, Marilena; Alamo, Angela; Palermo, Filippo; Aguglia, Eugenio
2014-03-22
It is well established in studies across several countries that tobacco smoking is more prevalent among schizophrenic patients than the general population. Electronic cigarettes are becoming increasingly popular with smokers worldwide. To date there are no large randomized trials of electronic cigarettes in schizophrenic smokers. A well-designed trial is needed to compare efficacy and safety of these products in this special population. We have designed a randomized controlled trial investigating the efficacy and safety of electronic cigarette. The trial will take the form of a prospective 12-month randomized clinical study to evaluate smoking reduction, smoking abstinence and adverse events in schizophrenic smokers not intending to quit. We will also monitor quality of life, neurocognitive functioning and measure participants' perception and satisfaction of the product. A ≥50% reduction in the number of cigarettes/day from baseline, will be calculated at each study visit ("reducers"). Abstinence from smoking will be calculated at each study visit ("quitters"). Smokers who leave the study protocol before its completion and will carry out the Early Termination Visit or who will not satisfy the criteria of "reducers" and "quitters" will be defined "non responders". The differences of continuous variables between the three groups will be evaluated with the Kruskal-Wallis Test, followed by the Dunn multiple comparison test. The differences between the three groups for normally distributed data will be evaluated with ANOVA test one way, followed by the Newman-Keuls multiple comparison test. The normality of the distribution will be evaluated with the Kolmogorov-Smirnov test. Any correlations between the variables under evaluation will be assessed by Spearman r correlation. To compare qualitative data will be used the Chi-square test. The main strengths of the SCARIS study are the following: it's the first large RCT on schizophrenic patient, involving in and outpatient, evaluating the effect of a three-arm study design, and a long term of follow-up (52-weeks).The goal is to propose an effective intervention to reduce the risk of tobacco smoking, as a complementary tool to treat tobacco addiction in schizophrenia. ClinicalTrials.gov, NCT01979796.
Statistical technique for analysing functional connectivity of multiple spike trains.
Masud, Mohammad Shahed; Borisyuk, Roman
2011-03-15
A new statistical technique, the Cox method, used for analysing functional connectivity of simultaneously recorded multiple spike trains is presented. This method is based on the theory of modulated renewal processes and it estimates a vector of influence strengths from multiple spike trains (called reference trains) to the selected (target) spike train. Selecting another target spike train and repeating the calculation of the influence strengths from the reference spike trains enables researchers to find all functional connections among multiple spike trains. In order to study functional connectivity an "influence function" is identified. This function recognises the specificity of neuronal interactions and reflects the dynamics of postsynaptic potential. In comparison to existing techniques, the Cox method has the following advantages: it does not use bins (binless method); it is applicable to cases where the sample size is small; it is sufficiently sensitive such that it estimates weak influences; it supports the simultaneous analysis of multiple influences; it is able to identify a correct connectivity scheme in difficult cases of "common source" or "indirect" connectivity. The Cox method has been thoroughly tested using multiple sets of data generated by the neural network model of the leaky integrate and fire neurons with a prescribed architecture of connections. The results suggest that this method is highly successful for analysing functional connectivity of simultaneously recorded multiple spike trains. Copyright © 2011 Elsevier B.V. All rights reserved.
Koerner, Tess K; Zhang, Yang
2017-02-27
Neurophysiological studies are often designed to examine relationships between measures from different testing conditions, time points, or analysis techniques within the same group of participants. Appropriate statistical techniques that can take into account repeated measures and multivariate predictor variables are integral and essential to successful data analysis and interpretation. This work implements and compares conventional Pearson correlations and linear mixed-effects (LME) regression models using data from two recently published auditory electrophysiology studies. For the specific research questions in both studies, the Pearson correlation test is inappropriate for determining strengths between the behavioral responses for speech-in-noise recognition and the multiple neurophysiological measures as the neural responses across listening conditions were simply treated as independent measures. In contrast, the LME models allow a systematic approach to incorporate both fixed-effect and random-effect terms to deal with the categorical grouping factor of listening conditions, between-subject baseline differences in the multiple measures, and the correlational structure among the predictor variables. Together, the comparative data demonstrate the advantages as well as the necessity to apply mixed-effects models to properly account for the built-in relationships among the multiple predictor variables, which has important implications for proper statistical modeling and interpretation of human behavior in terms of neural correlates and biomarkers.
Dose finding with the sequential parallel comparison design.
Wang, Jessie J; Ivanova, Anastasia
2014-01-01
The sequential parallel comparison design (SPCD) is a two-stage design recommended for trials with possibly high placebo response. A drug-placebo comparison in the first stage is followed in the second stage by placebo nonresponders being re-randomized between drug and placebo. We describe how SPCD can be used in trials where multiple doses of a drug or multiple treatments are compared with placebo and present two adaptive approaches. We detail how to analyze data in such trials and give recommendations about the allocation proportion to placebo in the two stages of SPCD.
Bednarz, Wojciech; Żurek, Jacek; Gedrange, Thomas; Dominiak, Marzena
2016-01-01
The most effective method for treating gingival recessions (GR) is with an autogenous connective tissue graft (CTG) via flap surgery. Often, however, the amount of CTG that can be grafted is insufficient to cover all of a patient's gingival recessions at one time. The objective of this study was to provide a 6-month comparative assessment of the results of covering multiple Miller Class I and II gingival recessions with a Fascia Lata Allograft (FL) and a CTG harvested from palatal mucosa. The study comprised a total of 30 people who underwent multiple gingival recession (GR) procedures using a modified, coronally advanced tunnel technique (MCAT). The patients were divided into two groups of 15 according to the type of materials used for gingival augmentation purposes: FL for the test group and CTG for the control group. A clinical assessment was made at baseline, as well as 3 and 6 months following surgery. The following factors were assessed: recession depth, recession width, probing depth, clinical attachment level, height of keratinized tissue (HKT), distance between the cemento-enamel junction and the muco-gingival junction (CEJ-MGJ), API, SBI. The following values were calculated: average root coverage (ARC), complete root coverage (CRC). No statistically significant differences were observed between the groups in terms of clinical parameters assessed after 6 months, apart from CRC, which was 94.87 ± 0.14 mm in the control group and 94.24 ± 0.20 mm in the study group (p = 0.034). The average HKT in the control group after 6 months amounted to 2.86 ± 1.60 mm, and in the test group to 3.09 ± 0.95 mm, which translates into an increase in comparison to the baseline values of 0.73 mm (p < 0.001) and 0.48 mm (p = 0.017), respectively. FL Allografts may serve as an alternative to autogenous CTG in multiple gingival recession coverage procedures based on the tunnel technique.
A comparison of between- and within-subjects imitation designs.
Kressley, Regina A; Knopf, Monika
2006-12-01
Two experimental methods, which have dominated the study of declarative memory in preverbal children with imitation tasks, namely the deferred imitation and elicited imitation paradigm, differ in the amount of physical contact with test stimuli afforded infants prior to a test for long-term recall. The current study assessed effects of pre- and post-demonstration contact with test stimuli on deferred imitation of novel, single-step unrelated actions with multiple objects by 8(1/2)- and 10(1/2)-month-old infants (N=50). The rate of target action completion after a delay remained consistent at both ages across different conditions of prior contact with test stimuli. This study shows that a within-subjects baseline appraisal is valid within certain experimental parameters and offers a more economical alternative. The results show furthermore that different experimental designs utilized to assess deferred imitation are highly comparable for the first year despite differences in determining baseline.
Uchida, K; Nishimura, T; Takesada, H; Morioka, T; Hagawa, N; Yamamoto, T; Kaga, S; Terada, T; Shinyama, N; Yamamoto, H; Mizobata, Y
2017-08-01
The purpose of this study was to assess the effects of recent surgical rib fixation and establish its indications not only for flail chest but also for multiple rib fractures. Between 2007 and 2015, 187 patients were diagnosed as having multiple rib fractures in our institution. After the propensity score matching was performed, ten patients who had performed surgical rib fixation and ten patients who had treated with non-operative management were included. Categorical variables were analyzed with Fischer's exact test and non-parametric numerical data were compared using the Mann-Whitney U test. Wilcoxon signed-rank test was performed for comparison of pre- and postoperative variables. All statistical data are presented as median (25-75 % interquartile range [IQR]) or number. The surgically treated patients extubated significantly earlier than non-operative management patients (5.5 [1-8] vs 9 [7-12] days: p = 0.019). The duration of continuous intravenous narcotic agents infusion days (4.5 [3-6] vs 12 [9-14] days: p = 0.002) and the duration of intensive care unit stay (6.5 [3-9] vs 12 [8-14] days: p = 0.008) were also significantly shorter in surgically treated patients. Under the same ventilating conditions, the postoperative values of tidal volume and respiratory rate improved significantly compared to those values measured just before the surgery. The incidence of pneumonia as a complication was significantly higher in non-operative management group (p = 0.05). From the viewpoints of early respiratory stabilization and intensive care unit disposition without any complications, surgical rib fixation is a sufficiently acceptable procedure not only for flail chest but also for repair of severe multiple rib fractures.
Statistical testing and power analysis for brain-wide association study.
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.
Avoiding false discoveries in association studies.
Sabatti, Chiara
2007-01-01
We consider the problem of controlling false discoveries in association studies. We assume that the design of the study is adequate so that the "false discoveries" are potentially only because of random chance, not to confounding or other flaws. Under this premise, we review the statistical framework for hypothesis testing and correction for multiple comparisons. We consider in detail the currently accepted strategies in linkage analysis. We then examine the underlying similarities and differences between linkage and association studies and document some of the most recent methodological developments for association mapping.
NASA Technical Reports Server (NTRS)
Williams, Jonathan H.
2010-01-01
The Upper Stage Reaction Control System provides three-axis attitude control for the Ares I launch vehicle during active Upper Stage flight. The system design must accommodate rapid thruster firing to maintain the proper launch trajectory and thus allow for the possibility to pulse multiple thrusters simultaneously. Rapid thruster valve closure creates an increase in static pressure, known as waterhammer, which propagates throughout the propellant system at pressures exceeding nominal design values. A series of development tests conducted in the fall of 2009 at Marshall Space Flight Center were performed using a water-flow test article to better understand fluid performance characteristics of the Upper Stage Reaction Control System. A subset of the tests examined waterhammer along with the subsequent pressure and frequency response in the flight-representative system and provided data to anchor numerical models. This thesis presents a comparison of waterhammer test results with numerical model and analytical results. An overview of the flight system, test article, modeling and analysis are also provided.
Use of Pearson's Chi-Square for Testing Equality of Percentile Profiles across Multiple Populations.
Johnson, William D; Beyl, Robbie A; Burton, Jeffrey H; Johnson, Callie M; Romer, Jacob E; Zhang, Lei
2015-08-01
In large sample studies where distributions may be skewed and not readily transformed to symmetry, it may be of greater interest to compare different distributions in terms of percentiles rather than means. For example, it may be more informative to compare two or more populations with respect to their within population distributions by testing the hypothesis that their corresponding respective 10 th , 50 th , and 90 th percentiles are equal. As a generalization of the median test, the proposed test statistic is asymptotically distributed as Chi-square with degrees of freedom dependent upon the number of percentiles tested and constraints of the null hypothesis. Results from simulation studies are used to validate the nominal 0.05 significance level under the null hypothesis, and asymptotic power properties that are suitable for testing equality of percentile profiles against selected profile discrepancies for a variety of underlying distributions. A pragmatic example is provided to illustrate the comparison of the percentile profiles for four body mass index distributions.
NASA Astrophysics Data System (ADS)
Williams, Jonathan Hunter
The Upper Stage Reaction Control System provides in-flight three-axis attitude control for the Ares I Upper Stage. The system design must accommodate rapid thruster firing to maintain proper launch trajectory and thus allow for the possibility to pulse multiple thrusters simultaneously. Rapid thruster valve closure creates an increase in static pressure, known as waterhammer, which propagates throughout the propellant system at pressures exceeding nominal design values. A series of development tests conducted at Marshall Space Flight Center in 2009 were performed using a water-flow test article to better understand fluid characteristics of the Upper Stage Reaction Control System. A subset of the tests examined the waterhammer pressure and frequency response in the flight-representative system and provided data to anchor numerical models. This thesis presents a comparison of waterhammer test results with numerical model and analytical results. An overview of the flight system, test article, modeling and analysis are also provided.
2013-01-01
Background Perturbations in intestinal microbiota composition have been associated with a variety of gastrointestinal tract-related diseases. The alleviation of symptoms has been achieved using treatments that alter the gastrointestinal tract microbiota toward that of healthy individuals. Identifying differences in microbiota composition through the use of 16S rRNA gene hypervariable tag sequencing has profound health implications. Current computational methods for comparing microbial communities are usually based on multiple alignments and phylogenetic inference, making them time consuming and requiring exceptional expertise and computational resources. As sequencing data rapidly grows in size, simpler analysis methods are needed to meet the growing computational burdens of microbiota comparisons. Thus, we have developed a simple, rapid, and accurate method, independent of multiple alignments and phylogenetic inference, to support microbiota comparisons. Results We create a metric, called compression-based distance (CBD) for quantifying the degree of similarity between microbial communities. CBD uses the repetitive nature of hypervariable tag datasets and well-established compression algorithms to approximate the total information shared between two datasets. Three published microbiota datasets were used as test cases for CBD as an applicable tool. Our study revealed that CBD recaptured 100% of the statistically significant conclusions reported in the previous studies, while achieving a decrease in computational time required when compared to similar tools without expert user intervention. Conclusion CBD provides a simple, rapid, and accurate method for assessing distances between gastrointestinal tract microbiota 16S hypervariable tag datasets. PMID:23617892
Yang, Fang; Chia, Nicholas; White, Bryan A; Schook, Lawrence B
2013-04-23
Perturbations in intestinal microbiota composition have been associated with a variety of gastrointestinal tract-related diseases. The alleviation of symptoms has been achieved using treatments that alter the gastrointestinal tract microbiota toward that of healthy individuals. Identifying differences in microbiota composition through the use of 16S rRNA gene hypervariable tag sequencing has profound health implications. Current computational methods for comparing microbial communities are usually based on multiple alignments and phylogenetic inference, making them time consuming and requiring exceptional expertise and computational resources. As sequencing data rapidly grows in size, simpler analysis methods are needed to meet the growing computational burdens of microbiota comparisons. Thus, we have developed a simple, rapid, and accurate method, independent of multiple alignments and phylogenetic inference, to support microbiota comparisons. We create a metric, called compression-based distance (CBD) for quantifying the degree of similarity between microbial communities. CBD uses the repetitive nature of hypervariable tag datasets and well-established compression algorithms to approximate the total information shared between two datasets. Three published microbiota datasets were used as test cases for CBD as an applicable tool. Our study revealed that CBD recaptured 100% of the statistically significant conclusions reported in the previous studies, while achieving a decrease in computational time required when compared to similar tools without expert user intervention. CBD provides a simple, rapid, and accurate method for assessing distances between gastrointestinal tract microbiota 16S hypervariable tag datasets.
Park, Tae Hwan; Park, Ji Hae; Tirgan, Michael H; Halim, Ahmad Sukari; Chang, Choong Hyun
2015-02-01
There is strong evidence of genetic susceptibility in individuals with keloid disorder. The purpose of this cross-sectional study was to determine the clinical relevance of our proposed variables on the multiplicity of keloids by further investigating the presence of other keloids and a family history. This was a retrospective review, using institutional review board-approved questionnaires, of patients with keloids who were seen at Kangbuk Samsung Hospital between December 2002 and February 2010. Eight hundred sixty-eight patients were included in our study. Comparisons between the 2 groups were made using Mann-Whitney tests for continuous variables and χ2 tests for categorical variables. In our patient group, younger age of onset and the presence of family history were significantly associated with the occurrence of keloids at multiple sites. The locations of extra-auricular keloids, in order of frequency, included the shoulder; anterior chest, including the breasts; deltoid; trunk and pubic area; upper extremities; lower extremities; and other sites. As compared to secondary keloids, primary keloids were significantly associated with both a lower degree of recurrence and the presence of other keloids. The presence or absence of family history was significantly associated with the presence or absence of other keloids and primary or secondary keloids. Keloid disorder is one of the most frustrating problems in wound healing and advances in our understanding of the differences of occurrence at a single site versus multiple sites might help in understanding pathogenesis and improving treatment.
An integrative formal model of motivation and decision making: The MGPM*.
Ballard, Timothy; Yeo, Gillian; Loft, Shayne; Vancouver, Jeffrey B; Neal, Andrew
2016-09-01
We develop and test an integrative formal model of motivation and decision making. The model, referred to as the extended multiple-goal pursuit model (MGPM*), is an integration of the multiple-goal pursuit model (Vancouver, Weinhardt, & Schmidt, 2010) and decision field theory (Busemeyer & Townsend, 1993). Simulations of the model generated predictions regarding the effects of goal type (approach vs. avoidance), risk, and time sensitivity on prioritization. We tested these predictions in an experiment in which participants pursued different combinations of approach and avoidance goals under different levels of risk. The empirical results were consistent with the predictions of the MGPM*. Specifically, participants pursuing 1 approach and 1 avoidance goal shifted priority from the approach to the avoidance goal over time. Among participants pursuing 2 approach goals, those with low time sensitivity prioritized the goal with the larger discrepancy, whereas those with high time sensitivity prioritized the goal with the smaller discrepancy. Participants pursuing 2 avoidance goals generally prioritized the goal with the smaller discrepancy. Finally, all of these effects became weaker as the level of risk increased. We used quantitative model comparison to show that the MGPM* explained the data better than the original multiple-goal pursuit model, and that the major extensions from the original model were justified. The MGPM* represents a step forward in the development of a general theory of decision making during multiple-goal pursuit. (PsycINFO Database Record (c) 2016 APA, all rights reserved).
Fujita, Yukiyoshi; Yamamoto, Koujirou; Aomori, Tohru; Murakami, Hirokazu; Horiuchi, Ryuya
2008-10-01
Thalidomide is an important advance in the treatment of multiple myeloma. In Japan thalidomide is now on the approval step for the treatment of multiple myeloma. The drug has some bothersome side effects such as defect of organogenesis, neuropathy, constipation and fatigue, but is likely more effective than standard chemotherapy and is changing multiple myeloma treatment. At this moment, Japanese patients must import the thalidomide preparations from Mexico, Britain and elsewhere, but after approval, they patients will be able to get the new Japanese thalidomide capsules. In order to determine appropriate amounts of Japanese thalidomide capsules in the treatment of multiple myeloma, we compared the dissolution profile and plasma thalidomide concentrations of Japanese and British capsules and Mexican tablets. The dissolution test was performed according to the Japanese and the United States Pharmacopoeia. The pharmacokinetic data for Japanese capsules were obtained from the clinical trial in Japanese subjects and compared with those data published for other formulations. The dissolution rate of the Japanese capsule was the fastest, followed by British and Mexican formulations. The pharmacokinetic profiles of Japanese and British capsules were similar, while the 100 mg Japanese thalidomide capsule demonstrated a 1.6-fold higher maximum plasma concentration than the 200 mg Mexican thalidomide tablet (1.7 vs. 1.1 microg/ml), greatly shortened t(max) (4.5 vs. 6.2 h), and the apparent half life was only one-third of the Mexican tablet (4.8 vs. 13.5 h). A comparison of the dissolution and the pharmacokinetic absorption profiles demonstrated a rank-order correlation. Physicians and pharmacists should be aware of the probable alteration in plasma thalidomide concentration when switching to the Japanese capsule, especially from the Mexican tablet, and should monitor clinical response carefully.
Hodgetts, William; Scott, Dylan; Maas, Patrick; Westover, Lindsey
2018-03-23
To determine if a newly-designed, forehead-mounted surface microphone would yield equivalent estimates of audibility when compared to audibility measured with a skull simulator for adult bone conduction users. Data was analyzed using a within subjects, repeated measures design. There were two different sensors (skull simulator and surface microphone) measuring the same hearing aid programmed to the same settings for all subjects. We were looking for equivalent results. Twenty-one adult percutaneous bone conduction users (12 females and 9 males) were recruited for this study. Mean age was 54.32 years with a standard deviation of 14.51 years. Nineteen of the subjects had conductive/mixed hearing loss and two had single-sided deafness. To define audibility, we needed to establish two things: (1) in situ-level thresholds at each audiometric frequency in force (skull simulator) and in sound pressure level (SPL; surface microphone). Next, we measured the responses of the preprogrammed test device in force on the skull simulator and in SPL on the surface mic in response to pink noise at three input levels: 55, 65, and 75 dB SPL. The skull simulator responses were converted to real head force responses by means of an individual real head to coupler difference transform. Subtracting the real head force level thresholds from the real head force output of the test aid yielded the audibility for each audiometric frequency for the skull simulator. Subtracting the SPL thresholds from the surface microphone from the SPL output of the test aid yielded the audibility for each audiometric frequency for the surface microphone. The surface microphone was removed and retested to establish the test-retest reliability of the tool. We ran a 2 (sensor) × 3 (input level) × 10 (frequency) mixed analysis of variance to determine if there were any significant main effects and interactions. There was a significant three-way interaction, so we proceeded to explore our planned comparisons. There were 90 planned comparisons of interest, three at each frequency (3 × 10) for the three input levels (30 × 3). Therefore, to minimize a type 1 error associated with multiple comparisons, we adjusted alpha using the Holm-Bonferroni method. There were five comparisons that yielded significant differences between the skull simulator and surface microphone (test and retest) in the estimation of audibility. However, the mean difference in these effects was small at 3.3 dB. Both sensors yielded equivalent results for the majority of comparisons. Models of bone conduction devices that have intact skin cannot be measured with the skull simulator. This study is the first to present and evaluate a new tool for bone conduction verification. The surface microphone is capable of yielding equivalent audibility measurements as the skull simulator for percutaneous bone conduction users at multiple input levels. This device holds potential for measuring other bone conduction devices (Sentio, BoneBridge, Attract, Soft headband devices) that do not have a percutaneous implant.
Differences between h-index measures from different bibliographic sources and search engines.
Barreto, Mauricio Lima; Aragão, Erika; Sousa, Luis Eugenio Portela Fernandes de; Santana, Táris Maria; Barata, Rita Barradas
2013-04-01
To analyze the use of the h-index as a measure of the bibliometric impact of Brazilian researchers' scientific publications. The scientific production of Brazilian CNPq 1-A researchers in the areas of public health, immunology and medicine were compared. The mean h-index of the groups of researchers in each area were estimated and nonparametric Kruskal Wallis test and multiple comparisons Behrens-Fisher test were used to compare the differences. The h-index means were higher in the area of Immunology than in Public Health and Medicine when the Web of Science base was used. However, this difference disappears when the comparison is made using Scopus or Google Scholar. The emergence of Google Scholar brings a new level to discussions on the measure of the bibliometric impact of scientific publications. Areas with strong professional components, in which knowledge is produced and must also be published in the native language, vis-a-vis its dissemination to the international community, necessarily have a standard of scientific publications and citations different from areas exclusively or predominantly academic and they are best captured by Google Scholar.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Cao, Y; Li, R; Chi, Z
Purpose: To compare the performances of four commercial treatment planning systems (TPS) used for the intensity-modulated radiotherapy (IMRT). Methods: Ten patients of nasopharyngeal (4 cases), esophageal (3 cases) and cervical (3 cases) cancer were randomly selected from a 3-month IMRT plan pool at one radiotherapy center. For each patient, four IMRT plans were newly generated by using four commercial TPS (Corvus, Monaco, Pinnacle and Xio), and then verified with Matrixx (two-dimensional array/IBA Company) on Varian23EX accelerator. A pass rate (PR) calculated from the Gamma index by OminiPro IMRT 1.5 software was evaluated at four plan verification standards (1%/1mm, 2%/2mm, 3%/3mm,more » 4%/4mm and 5%/5mm) for each treatment plan. Overall and multiple pairwise comparisons of PRs were statistically conducted by analysis of covariance (ANOVA) F and LSD tests among four TPSs. Results: Overall significant (p>0.05) differences of PRs were found among four TPSs with F test values of 3.8 (p=0.02), 21.1(>0.01), 14.0 (>0.01), 8.3(>0.01) at standards of 1%/1mm to 4%/4mm respectively, except at 5%/5mm standard with 2.6 (p=0.06). All means (standard deviation) of PRs at 3%/3mm of 94.3 ± 3.3 (Corvus), 98.8 ± 0.8 (Monaco), 97.5± 1.7 (Pinnacle), 98.4 ± 1.0 (Xio) were above 90% and met clinical requirement. Multiple pairwise comparisons had not demonstrated a consistent low or high pattern on either TPS. Conclusion: Matrixx dose verification results show that the validation pass rates of Monaco and Xio plans are relatively higher than those of the other two; Pinnacle plan shows slight higher pass rate than Corvus plan; lowest pass rate was achieved by the Corvus plan among these four kinds of TPS.« less
A graphics-card implementation of Monte-Carlo simulations for cosmic-ray transport
NASA Astrophysics Data System (ADS)
Tautz, R. C.
2016-05-01
A graphics card implementation of a test-particle simulation code is presented that is based on the CUDA extension of the C/C++ programming language. The original CPU version has been developed for the calculation of cosmic-ray diffusion coefficients in artificial Kolmogorov-type turbulence. In the new implementation, the magnetic turbulence generation, which is the most time-consuming part, is separated from the particle transport and is performed on a graphics card. In this article, the modification of the basic approach of integrating test particle trajectories to employ the SIMD (single instruction, multiple data) model is presented and verified. The efficiency of the new code is tested and several language-specific accelerating factors are discussed. For the example of isotropic magnetostatic turbulence, sample results are shown and a comparison to the results of the CPU implementation is performed.
Storck, Michael; Krumm, Rainer; Dugas, Martin
2016-01-01
Medical documentation is applied in various settings including patient care and clinical research. Since procedures of medical documentation are heterogeneous and developed further, secondary use of medical data is complicated. Development of medical forms, merging of data from different sources and meta-analyses of different data sets are currently a predominantly manual process and therefore difficult and cumbersome. Available applications to automate these processes are limited. In particular, tools to compare multiple documentation forms are missing. The objective of this work is to design, implement and evaluate the new system ODMSummary for comparison of multiple forms with a high number of semantically annotated data elements and a high level of usability. System requirements are the capability to summarize and compare a set of forms, enable to estimate the documentation effort, track changes in different versions of forms and find comparable items in different forms. Forms are provided in Operational Data Model format with semantic annotations from the Unified Medical Language System. 12 medical experts were invited to participate in a 3-phase evaluation of the tool regarding usability. ODMSummary (available at https://odmtoolbox.uni-muenster.de/summary/summary.html) provides a structured overview of multiple forms and their documentation fields. This comparison enables medical experts to assess multiple forms or whole datasets for secondary use. System usability was optimized based on expert feedback. The evaluation demonstrates that feedback from domain experts is needed to identify usability issues. In conclusion, this work shows that automatic comparison of multiple forms is feasible and the results are usable for medical experts.
The ‘Pokemon’ (ZBTB7) Gene: No Evidence of Association with Sporadic Breast Cancer
Salas, Antonio; Vega, Ana; Milne, Roger L.; García-Magariños, Manuel; Ruibal, Álvaro; Benítez, Javier; Carracedo, Ángel
2008-01-01
It has been proposed that the excess of familiar risk associated with breast cancer could be explained by the cumulative effect of multiple weakly predisposing alleles. The transcriptional repressor FBI1, also known as Pokemon, has recently been identified as a critical factor in oncogenesis. This protein is encoded by the ZBTB7 gene. Here we aimed to determine whether polymorphisms in ZBTB7 are associated with breast cancer risk in a sample of cases and controls collected in hospitals from North and Central Spanish patients. We genotyped 15 SNPs in ZBTB7, including the flanking regions, with an average coverage of 1 SNP/2.4 Kb, in 360 sporadic breast cancer cases and 402 controls. Comparison of allele, genotype and haplotype frequencies between cases and controls did not reveal associations using Pearson’s chi-square test and a permutation procedure to correct for multiple test. In this, the first study of the ZBTB7 gene in relation to, sporadic breast cancer, we found no evidence of an association. PMID:21892298
A Comparison of Approximation Modeling Techniques: Polynomial Versus Interpolating Models
NASA Technical Reports Server (NTRS)
Giunta, Anthony A.; Watson, Layne T.
1998-01-01
Two methods of creating approximation models are compared through the calculation of the modeling accuracy on test problems involving one, five, and ten independent variables. Here, the test problems are representative of the modeling challenges typically encountered in realistic engineering optimization problems. The first approximation model is a quadratic polynomial created using the method of least squares. This type of polynomial model has seen considerable use in recent engineering optimization studies due to its computational simplicity and ease of use. However, quadratic polynomial models may be of limited accuracy when the response data to be modeled have multiple local extrema. The second approximation model employs an interpolation scheme known as kriging developed in the fields of spatial statistics and geostatistics. This class of interpolating model has the flexibility to model response data with multiple local extrema. However, this flexibility is obtained at an increase in computational expense and a decrease in ease of use. The intent of this study is to provide an initial exploration of the accuracy and modeling capabilities of these two approximation methods.
Usadel, Björn; Nagel, Axel; Steinhauser, Dirk; Gibon, Yves; Bläsing, Oliver E; Redestig, Henning; Sreenivasulu, Nese; Krall, Leonard; Hannah, Matthew A; Poree, Fabien; Fernie, Alisdair R; Stitt, Mark
2006-12-18
Microarray technology has become a widely accepted and standardized tool in biology. The first microarray data analysis programs were developed to support pair-wise comparison. However, as microarray experiments have become more routine, large scale experiments have become more common, which investigate multiple time points or sets of mutants or transgenics. To extract biological information from such high-throughput expression data, it is necessary to develop efficient analytical platforms, which combine manually curated gene ontologies with efficient visualization and navigation tools. Currently, most tools focus on a few limited biological aspects, rather than offering a holistic, integrated analysis. Here we introduce PageMan, a multiplatform, user-friendly, and stand-alone software tool that annotates, investigates, and condenses high-throughput microarray data in the context of functional ontologies. It includes a GUI tool to transform different ontologies into a suitable format, enabling the user to compare and choose between different ontologies. It is equipped with several statistical modules for data analysis, including over-representation analysis and Wilcoxon statistical testing. Results are exported in a graphical format for direct use, or for further editing in graphics programs.PageMan provides a fast overview of single treatments, allows genome-level responses to be compared across several microarray experiments covering, for example, stress responses at multiple time points. This aids in searching for trait-specific changes in pathways using mutants or transgenics, analyzing development time-courses, and comparison between species. In a case study, we analyze the results of publicly available microarrays of multiple cold stress experiments using PageMan, and compare the results to a previously published meta-analysis.PageMan offers a complete user's guide, a web-based over-representation analysis as well as a tutorial, and is freely available at http://mapman.mpimp-golm.mpg.de/pageman/. PageMan allows multiple microarray experiments to be efficiently condensed into a single page graphical display. The flexible interface allows data to be quickly and easily visualized, facilitating comparisons within experiments and to published experiments, thus enabling researchers to gain a rapid overview of the biological responses in the experiments.
A search for association between schizophrenia and dopamine-related alleles.
Jönsson, E; Brené, S; Geijer, T; Terenius, L; Tylec, A; Persson, M L; Sedvall, G
1996-01-01
Dopamine receptor dysfunction and altered tyrosine hydroxylase activity have both been implicated in the pathophysiology of schizophrenia. Schizophrenic patients and control subjects were examined for allele frequencies in the tyrosine hydroxylase and dopamine D2 and D4 receptor genes. No significant differences of allele or genotype frequencies were found between the two groups after adjustment for multiple comparisons. Neither were any significant relationships observed between allele frequencies and a number of clinical variables within the schizophrenic subsample. When no adjustment was made for multiple testing a few significant tendencies were obtained which warrant further research in extended patient and control materials. The results are compatible with the view that the tyrosine hydroxylase, dopamine receptor D2 and D4 gene polymorphisms examined are not of major importance in the aetiology or pathophysiology of schizophrenia.
Autonomous Scanning Probe Microscopy in Situ Tip Conditioning through Machine Learning.
Rashidi, Mohammad; Wolkow, Robert A
2018-05-23
Atomic-scale characterization and manipulation with scanning probe microscopy rely upon the use of an atomically sharp probe. Here we present automated methods based on machine learning to automatically detect and recondition the quality of the probe of a scanning tunneling microscope. As a model system, we employ these techniques on the technologically relevant hydrogen-terminated silicon surface, training the network to recognize abnormalities in the appearance of surface dangling bonds. Of the machine learning methods tested, a convolutional neural network yielded the greatest accuracy, achieving a positive identification of degraded tips in 97% of the test cases. By using multiple points of comparison and majority voting, the accuracy of the method is improved beyond 99%.
A new blended learning concept for medical students in otolaryngology.
Grasl, Matthaeus C; Pokieser, Peter; Gleiss, Andreas; Brandstaetter, Juergen; Sigmund, Thorsten; Erovic, Boban M; Fischer, Martin R
2012-04-01
To evaluate students' overall assessment and effectiveness of the web-based blended learning conception "Unified Patient Project" (UPP) for medical students rotating on their otolaryngology internship (ear, nose, and throat [ENT] tertiary). Prospective comparison group design of the quasiexperimental type. Medical education. The experimental group (preintervention test [pretest], intervention, and postintervention test [posttest]) comprised 117 students, and the comparison group (pretest, alternative intervention, and posttest), 119. In the experimental group, lecturing of case studies was replaced by the blended learning concept UPP. A standardized questionnaire evaluated students' overall assessment of teaching otolaryngology. A pretest and posttest using multiple choice questions was administered to clarify whether the UPP has led to a knowledge gain. The comparison group was more satisfied with their teaching; however, this was not statistically significant (P = .26) compared with the UPP. Students with higher preknowledge benefitted from the UPP, while students with lower preknowledge did not (P = .01). On average, posttest results in the experimental group exceeded those of the comparison group by 8.7 percentage points for a 75% preknowledge of the maximum attainable score, while they fell below those of the comparison group by 8.1 percentage points for a 25% preknowledge. Students' satisfaction with the blended learning concept UPP was lower than in the face-to-face teaching, although this was not statistically significant. The new web-based UPP leads to an improved knowledge in clinical otolaryngology for all students. Students with lower preknowledge benefitted more from face-to-face teaching than from the UPP, while students with higher preknowledge benefitted more from the UPP. This implies students with poor preknowledge need special promotion programs.
Moazami, Fariborz; Bahrampour, Ehsan; Azar, Mohammad Reza; Jahedi, Farzad; Moattari, Marzieh
2014-03-05
The importance of using technologies such as e-learning in different disciplines is discussed in the literature. Researchers have measured the effectiveness of e-learning in a number of fields.Considering the lack of research on the effectiveness of online learning in dental education particularly in Iran, the advantages of these learning methods and the positive university atmosphere regarding the use of online learning. This study, therefore, aims to compare the effects of two methods of teaching (virtual versus traditional) on student learning. This post-test only design study approached 40, fifth year dental students of Shiraz University of Medical Sciences. From this group, 35 students agreed to participate. These students were randomly allocated into two groups, experimental (virtual learning) and comparison (traditional learning). To ensure similarity between groups, we compared GPAs of all participants by the Mann-Whitney U test (P > 0.05). The experimental group received a virtual learning environment courseware package specifically designed for this study, whereas the control group received the same module structured in a traditional lecture form. The virtual learning environment consisted of online and offline materials. Two identical valid, reliable post-tests that consisted of 40 multiple choice questions (MCQs) and 4 essay questions were administered immediately (15 min) after the last session and two months later to assess for knowledge retention. Data were analyzed by SPSS version 20. A comparison of the mean knowledge score of both groups showed that virtual learning was more effective than traditional learning (effect size = 0.69). The newly designed virtual learning package is feasible and will result in more effective learning in comparison with lecture-based training. However further studies are needed to generalize the findings of this study.
Toxicity testing of restorative dental materials using brine shrimp larvae (Artemia salina).
Milhem, Manar M; Al-Hiyasat, Ahmad S; Darmani, Homa
2008-01-01
This study investigated the effect of extracts of different composites, glass ionomer cement (GIC)s and compomers on the viability of brine shrimp larvae. Ethanolic extracts of four dental composites (Z-100; Solitaire 2; Filtek P60 and Synergy), a conventional GIC (Ketac-Fil), a resin-modified glass ionomer cement (Vitremer), two compomers (F2000; Dyract AP), and a flowable compomer (Dyract Flow) were prepared from each material. Following evaporation of the ethanol, the extracts were resuspended in distilled water, which was then used to test the effects on the viability of brine shrimp larvae. For the composites, the extract of Synergy was the least toxic (88% viability) followed by the extracts of Solitaire 2, Z100 and P60 (75%, 67.5% and 50% viability, respectively). One-way ANOVA revealed highly significant differences between the resin composite materials (p<0.001). Follow-up comparison between the composite groups by Tukey's pairwise multiple-comparison test (alpha =0.05) showed that the extract of Synergy was significantly less toxic than the extracts of all the other materials except that of Solitaire 2. The compomers showed 100% lethality, while the percentage of viable larvae for the extracts of Ketac-Fil, and Vitremer were 32.3%, and 37.0%, respectively. One-way ANOVA revealed highly significant differences between the groups of materials (p<0.001). Follow-up comparison between the groups by Tukey's test (alpha = 0.05) showed that the toxic effect of the extracts of the compomers were significantly greater than that of Ketac-Fil, and Vitremer. The differences in the toxic effects of Vitremer and Ketac-Fil were not statistically significant. In conclusion, the toxicity of composite materials varied according to their chemical composition. Compomers were the most lethal materials to brine shrimp larvae followed by GICs and then composites.
NASA Technical Reports Server (NTRS)
Patel, Deepak
2014-01-01
Thermal and Fluids Analysis Workshop, Cleveland OH. NCTS 19701-14. On Dec 2013 a Loop Heat Pipe (LHP) test was performed as part of the integral Laser Thermal Control System (LTCS). During the balance portion of this testing it was noticed that the LHP was not going to be able to maintain temperature on the operational thermal mass. The test was stopped. After multiple meetings with the LTCS designers, LHP experts (in house and external) it was concluded that gravity was preventing the control heaters to maintain control on the reservoir. A heater was installed onto the liquid return line as part of the fix. After implementing the fix on the liquid return line, the test on May 2014 proved that the system works in vertical orientation using the liquid line heater. Through this testing, the correlation of the Deepak Condenser Model (DeCoM) was possible. This paper describes how well DeCoM predicts the condenser behavior in comparison to the test results of LTCS test.
The Role of Multiple-Exemplar Training and Naming in Establishing Derived Equivalence in an Infant
Luciano, Carmen; Becerra, Inmaculada Gómez; Valverde, Miguel Rodríguez
2007-01-01
The conditions under which symmetry and equivalence relations develop are still controversial. This paper reports three experiments that attempt to analyze the impact of multiple-exemplar training (MET) in receptive symmetry on the emergence of visual–visual equivalence relations with a very young child, Gloria. At the age of 15 months 24 days (15m24d), Gloria was tested for receptive symmetry and naming and showed no evidence of either repertoire. In the first experiment, MET in immediate and delayed receptive symmetrical responding or listener behavior (from object–sound to immediate and delayed sound–object selection) proceeded for one month with 10 different objects. This was followed, at 16m25d, by a second test conducted with six new objects. Gloria showed generalized receptive symmetry with a 3-hr delay; however no evidence of naming with new objects was found. Experiment 2 began at 17m with the aim of establishing derived visual–visual equivalence relations using a matching-to-sample format with two comparisons. Visual–visual equivalence responding emerged at 19m, although Gloria still had not shown evidence of naming. Experiment 3 (22m to 23m25d) used a three-comparison matching-to-sample procedure to establish visual–visual equivalence. Equivalence responding emerged as in Experiment 2, and naming emerged by the end of Experiment 3. Results are discussed in terms of the history of training in bidirectional relations responsible for the emergence of visual–visual equivalence relations and of their implications for current theories of stimulus equivalence. PMID:17575901
Siega-Riz, Anna Maria; Haugen, Margaretha; Meltzer, Helle M; Von Holle, Ann; Hamer, Robert; Torgersen, Leila; Knopf-Berg, Cecilie; Reichborn-Kjennerud, Ted; Bulik, Cynthia M
2009-01-01
Background Little is known concerning the dietary habits of eating disordered women during pregnancy that may lie in the causal pathway of adverse birth outcomes. Objective To examine the nutrient and food group intake of women with bulimia nervosa (BN) and binge eating disorder (BED) during pregnancy and compare their intake to women with no eating disorders. Design Data on 30,040 mother-child pairs are from the prospective Norwegian Mother and Child Cohort Study was used in cross-sectional analyses. Dietary information was collected using a food frequency questionnaire during the first half of pregnancy. Statistical testing by eating disorder categories with the non-eating disorder category as the referent group were conducted using log (means) adjusted for confounding and multiple comparisons. Food group differences were conducted using a Wilcoxon two-sided normal approximation test also adjusting for multiple comparisons. Results Women with BED before and during pregnancy had higher intakes of total energy, total mono-saturated and saturated fat, and lower intakes of folate, potassium, and vitamin C compared to the referent (p<.02). Women with incident BED during pregnancy had higher total energy and saturated fat intake compared to the referent (p=.01). Several differences emerged in food group consumption between women with and without eating disorders including intakes of artificial sweeteners, sweets, juice, fruits and fats. Conclusions Women with BN before and during pregnancy and those with BED before pregnancy exhibit dietary patterns different from women without eating disorders, that are reflective of their symptomatology, and may influence pregnancy outcomes. PMID:18469258
Jeon, Young J.; Kim, Jaeuk U.; Lee, Hae J.; Lee, Jeon; Ryu, Hyun H.; Lee, Yu J.; Kim, Jong Y.
2011-01-01
In this work, we analyze the baseline, signal strength, aortic augmentation index (AIx), radial AIx, time to reflection and P_T2 at Chon, Gwan, and Cheok, which are the three pulse diagnosis positions in Oriental medicine. For the pulse measurement, we used the SphygmoCor apparatus, which has been widely used for the evaluation of the arterial stiffness at the aorta. By two-way repeated measures analysis of variance, we tested two independent measurements for repeatability and investigated their mean differences among Chon, Gwan and Cheok. To characterize further the parameters that were shown to be different between each palpation position, we carried out Duncan's test for the multiple comparisons. The baseline and signal strength were statistically different (P < .05) among Chon, Gwan and Cheok, respectively, which supports the major hypothesis of Oriental medicine that all of the three palpation positions contain different clinical information. On the other hand, aortic AIx and time to reflection were found to be statistically different between Chon and the others, and radial AIx and P_T2 did not show any difference between pulse positions. In the clinical sense, however, the aortic AIx at each palpation position was found to fall within the 90% confidence interval of normal arterial compliance. The results of the multiple comparisons indicate that the parameters of arterial stiffness were independent of the palpation positions. This work is the first attempt to characterize quantitatively the pulse signals at Chon, Gwan and Cheok with some relevant parameters extracted from the SphygmoCor apparatus. PMID:19789213
Manfredini, Marco; Arginelli, Federica; Dunsby, Christopher; French, Paul; Talbot, Clifford; König, Karsten; Pellacani, Giovanni; Ponti, Giovanni; Seidenari, Stefania
2013-02-01
The aim of this study was to compare morphological aspects of basal cell carcinoma (BCC) as assessed by two different imaging methods: in vivo reflectance confocal microscopy (RCM) and multiphoton tomography with fluorescence lifetime imaging implementation (MPT-FLIM). The study comprised 16 BCCs for which a complete set of RCM and MPT-FLIM images were available. The presence of seven MPT-FLIM descriptors was evaluated. The presence of seven RCM equivalent parameters was scored in accordance to their extension. Chi-squared test with Fisher's exact test and Spearman's rank correlation coefficient were determined between MPT-FLIM scores and adjusted-RCM scores. MPT-FLIM and RCM descriptors of BCC were coupled to match the descriptors that define the same pathological structures. The comparison included: Streaming and Aligned elongated cells, Streaming with multiple directions and Double alignment, Palisading (RCM) and Palisading (MPT-FLIM), Typical tumor islands, and Cell islands surrounded by fibers, Dark silhouettes and Phantom islands, Plump bright cells and Melanophages, Vessels (RCM), and Vessels (MPT-FLIM). The parameters that were significantly correlated were Melanophages/Plump Bright Cells, Aligned elongated cells/Streaming, Double alignment/Streaming with multiple directions, and Palisading (MPT-FLIM)/Palisading (RCM). According to our data, both methods are suitable to image BCC's features. The concordance between MPT-FLIM and RCM is high, with some limitations due to the technical differences between the two devices. The hardest difficulty when comparing the images generated by the two imaging modalities is represented by their different field of view. © 2012 John Wiley & Sons A/S.
Voxelwise multivariate analysis of multimodality magnetic resonance imaging
Naylor, Melissa G.; Cardenas, Valerie A.; Tosun, Duygu; Schuff, Norbert; Weiner, Michael; Schwartzman, Armin
2015-01-01
Most brain magnetic resonance imaging (MRI) studies concentrate on a single MRI contrast or modality, frequently structural MRI. By performing an integrated analysis of several modalities, such as structural, perfusion-weighted, and diffusion-weighted MRI, new insights may be attained to better understand the underlying processes of brain diseases. We compare two voxelwise approaches: (1) fitting multiple univariate models, one for each outcome and then adjusting for multiple comparisons among the outcomes and (2) fitting a multivariate model. In both cases, adjustment for multiple comparisons is performed over all voxels jointly to account for the search over the brain. The multivariate model is able to account for the multiple comparisons over outcomes without assuming independence because the covariance structure between modalities is estimated. Simulations show that the multivariate approach is more powerful when the outcomes are correlated and, even when the outcomes are independent, the multivariate approach is just as powerful or more powerful when at least two outcomes are dependent on predictors in the model. However, multiple univariate regressions with Bonferroni correction remains a desirable alternative in some circumstances. To illustrate the power of each approach, we analyze a case control study of Alzheimer's disease, in which data from three MRI modalities are available. PMID:23408378
Thermal behavior of crumb-rubber modified asphalt concrete mixtures
NASA Astrophysics Data System (ADS)
Epps, Amy Louise
Thermal cracking is one of the primary forms of distress in asphalt concrete pavements, resulting from either a single drop in temperature to an extreme low or from multiple temperature cycles above the fracture temperature of the asphalt-aggregate mixture. The first mode described is low temperature cracking; the second is thermal fatigue. The addition of crumb-rubber, manufactured from scrap tires, to the binder in asphalt concrete pavements has been suggested to minimize both types of thermal cracking. Four experiments were designed and completed to evaluate the thermal behavior of crumb-rubber modified (CRM) asphalt-aggregate mixtures. Modified and unmodified mixture response to thermal stresses was measured in four laboratory tests. The Thermal Stress Restrained Specimen Test (TSRST) and the Indirect Tensile Test (IDT) were used to compare mixture resistance to low temperature cracking. Modified mixtures showed improved performance, and cooling rate did not affect mixture resistance according to the statistical analysis. Therefore results from tests with faster rates can predict performance under slower field rates. In comparison, predicted fracture temperatures and stresses (IDT) were generally higher than measured values (TSRST). In addition, predicted fracture temperatures from binder test results demonstrated that binder testing alone is not sufficient to evaluate CRM mixtures. Thermal fatigue was explored in the third experiment using conventional load-induced fatigue tests with conditions selected to simulate daily temperature fluctuations. Test results indicated that thermal fatigue may contribute to transverse cracking in asphalt pavements. Both unmodified and modified mixtures had a finite capacity to withstand daily temperature fluctuations coupled with cold temperatures. Modified mixtures again exhibited improved performance. The fourth experiment examined fracture properties of modified and unmodified mixtures using a common fracture toughness test. Results showed no effect from modification, but the small experiment size may have masked this effect. Reliability concepts were introduced to include risk and uncertainty in a comparison of mixture response measured in the laboratory and estimated environmental conditions. This comparison provided evidence that CRM mixtures exhibit improved resistance to both types of thermal cracking at high levels of reliability. In conclusion, a mix design and analysis framework for evaluating thermal behavior was recommended.
Sinhal, Tapati Manohar; Shah, Ruchi Rani Purvesh; Jais, Pratik Subhas; Shah, Nimisha Chinmay; Hadwani, Krupali Dhirubhai; Rothe, Tushar; Sinhal, Neha Nilesh
2018-01-01
The aim of this study is to compare and to evaluate sealing ability of newly introduced C-point system, cold lateral condensation, and thermoplasticized gutta-percha obturating technique using a dye extraction method. Sixty extracted maxillary central incisors were decoronated below the cementoenamel junction. Working length was established, and biomechanical preparation was done using K3 rotary files with standard irrigation protocol. Teeth were divided into three groups according to the obturation protocol; Group I-Cold lateral condensation, Group II-Thermoplasticized gutta-percha, and Group III-C-Point obturating system. After obturation all samples were subjected to microleakage assessment using dye extraction method. Obtained scores will be statistical analyzed using ANOVA test and post hoc Tukey's test. One-way analysis of variance revealed that there is significant difference among the three groups with P value (0.000 < 0.05). Tukey's HSD post hoc tests for multiple comparisons test shows that the Group II and III perform significantly better than Group I. Group III performs better than Group II with no significant difference. All the obturating technique showed some degree of microleakage. Root canals filled with C-point system showed least microleakage followed by thermoplasticized obturating technique with no significant difference among them. C-point obturation system could be an alternative to the cold lateral condensation technique.
Ha, Seung-Ryong; Yang, Jae-Ho; Lee, Jai-Bong; Han, Jung-Suk; Kim, Sung-Hun
2010-03-01
The purpose of this study was to investigate the diametral tensile strength of polymer-based temporary crown and fixed partial denture (FPD) materials, and the change of the diametral tensile strength with time. One monomethacrylate-based temporary crown and FPD material (Trim) and three dimethacrylate-based ones (Protemp 3 Garant, Temphase, Luxtemp) were investigated. 20 specimens (ø 4 mm × 6 mm) were fabricated and randomly divided into two groups (Group I: Immediately, Group II: 1 hour) according to the measurement time after completion of mixing. Universal Testing Machine was used to load the specimens at a cross-head speed of 0.5 mm/min. The data were analyzed using one-way ANOVA, the multiple comparison Scheffe test and independent sample t test (α = 0.05). Trim showed severe permanent deformation without an obvious fracture during loading at both times. There were statistically significant differences among the dimethacrylate-based materials. The dimethacrylate-based materials presented an increase in strength from 5 minutes to 1 hour and were as follows: Protemp 3 Garant (23.16 - 37.6 MPa), Temphase (22.27 - 28.08 MPa), Luxatemp (14.46 - 20.59 MPa). Protemp 3 Garant showed the highest value. The dimethacrylate-based temporary materials tested were stronger in diametral tensile strength than the monomethacrylate-based one. The diametral tensile strength of the materials investigated increased with time.
Quantitative traits for the tail suspension test: automation, optimization, and BXD RI mapping.
Lad, Heena V; Liu, Lin; Payá-Cano, José L; Fernandes, Cathy; Schalkwyk, Leonard C
2007-07-01
Immobility in the tail suspension test (TST) is considered a model of despair in a stressful situation, and acute treatment with antidepressants reduces immobility. Inbred strains of mouse exhibit widely differing baseline levels of immobility in the TST and several quantitative trait loci (QTLs) have been nominated. The labor of manual scoring and various scoring criteria make obtaining robust data and comparisons across different laboratories problematic. Several studies have validated strain gauge and video analysis methods by comparison with manual scoring. We set out to find objective criteria for automated scoring parameters that maximize the biological information obtained, using a video tracking system on tapes of tail suspension tests of 24 lines of the BXD recombinant inbred panel and the progenitor strains C57BL/6J and DBA/2J. The maximum genetic effect size is captured using the highest time resolution and a low mobility threshold. Dissecting the trait further by comparing genetic association of multiple measures reveals good evidence for loci involved in immobility on chromosomes 4 and 15. These are best seen when using a high threshold for immobility, despite the overall better heritability at the lower threshold. A second trial of the test has greater duration of immobility and a completely different genetic profile. Frequency of mobility is also an independent phenotype, with a distal chromosome 1 locus.
Krüger, Jan-Christopher; Meves, Saskia H; Kara, Kaffer; Mügge, Andreas; Neubauer, Horst
2014-10-01
Several platelet function test systems exist for the evaluation of the platelet inhibitory effect in patients on P2Y12 inhibitors and/or acetylsalicylic acid (ASA, aspirin) therapy. Studies comparing different available assays found only a poor correlation. The objective of the present study was to evaluate the correlation and agreement between single electrode (SEA) and multiple electrode (MEA) aggregometry. In whole blood arachidonic acid (AA) and adenosine diphosphate (ADP)-induced platelet aggregation was measured simultaneously using SEA (Chrono-Log) and MEA (Multiplate). We analyzed a total of 226 measurements taken from 58 patients on single ASA therapy or dual antiplatelet therapy with ASA and a thienopyridine. A cut-off value for clopidogrel/prasugrel high on-treatment platelet reactivity (HPR) of > 47 units (U) was chosen for MEA testing using hirudin and > 5 Ohm for SEA with citrate anticoagulated blood samples. The respective cut-off values for ASA HPR were > 30 U for the MEA assay and > 1 Ohm for SEA testing. There was a good correlation of the prevalence of thienopyridine-HPR in both whole blood assays (Spearman rank correlation coefficient r = 0.698) and a good inter-rate accordance (Cohen's Kappa statistic κ = 0.648). For AA-induced aggregation, the correlation of the results obtained was significant (r = 0.536; p < 0.001) and detecting ASA-HPR revealed a moderate (κ = 0.482) correlation between both impedance aggregometry assays. Platelet function testing using SEA and MEA provided both good accordance and correlation and therefore study results obtained by these two assays similarly enabled the detection of HPR of thienopyridine (and ASA) therapy.
Registration and Fusion of Multiple Source Remotely Sensed Image Data
NASA Technical Reports Server (NTRS)
LeMoigne, Jacqueline
2004-01-01
Earth and Space Science often involve the comparison, fusion, and integration of multiple types of remotely sensed data at various temporal, radiometric, and spatial resolutions. Results of this integration may be utilized for global change analysis, global coverage of an area at multiple resolutions, map updating or validation of new instruments, as well as integration of data provided by multiple instruments carried on multiple platforms, e.g. in spacecraft constellations or fleets of planetary rovers. Our focus is on developing methods to perform fast, accurate and automatic image registration and fusion. General methods for automatic image registration are being reviewed and evaluated. Various choices for feature extraction, feature matching and similarity measurements are being compared, including wavelet-based algorithms, mutual information and statistically robust techniques. Our work also involves studies related to image fusion and investigates dimension reduction and co-kriging for application-dependent fusion. All methods are being tested using several multi-sensor datasets, acquired at EOS Core Sites, and including multiple sensors such as IKONOS, Landsat-7/ETM+, EO1/ALI and Hyperion, MODIS, and SeaWIFS instruments. Issues related to the coregistration of data from the same platform (i.e., AIRS and MODIS from Aqua) or from several platforms of the A-train (i.e., MLS, HIRDLS, OMI from Aura with AIRS and MODIS from Terra and Aqua) will also be considered.
Comparison of individual answer and group answer with and without structured peer assessment
NASA Astrophysics Data System (ADS)
Kablan, Zeynel
2014-09-01
Background:Cooperative learning activities provide active participation of students leading to better learning. The literature suggests that cooperative learning activities need to be structured for a more effective and productive interaction. Purpose: This study aimed to test the differences among three instructional conditions in terms of science achievement. Sample:A total of 79 fifth-grade students, 42 males (53%) and 37 females (47%), participated in the study. Design and Methods:In the first condition, students answered the teacher's questions individually by raising hands. In the second condition, students discussed the answer in groups and came up with a single group answer. In this condition, the teacher provided only verbal directions to the groups without using any strategy or material. In the third condition, students used a 'peer assessment form' before giving the group answer. A pre-/post-test experimental design was used. Multiple-choice and open-ended tests were used for data collection. One-way analysis of variance (ANOVA) was conducted to test the differences in the test scores between the three groups (individual answer, unstructured group answer and structured group answer). Results:Results showed that there were no significant differences among the three learning conditions in terms of their multiple-choice test scores. In terms of the open-ended test scores, students in the structured group answer condition scored significantly higher than the students in the individual answer condition. Conclusions:Structuring the group work through peer assessment helped to monitor the group discussion, provided a better learning compared to the individual answer condition, and helped students to participate in the activity equally.
Efficacy of group cognitive rehabilitation therapy in multiple sclerosis.
Mani, A; Chohedri, E; Ravanfar, P; Mowla, A; Nikseresht, A
2018-06-01
Cognitive impairment occurs in 40%-65% of patients with multiple sclerosis (MS). Several techniques for cognitive rehabilitation (CR) in these patients have been evaluated; however, the results have been controversial. In this study, we investigated the efficacy of group compensatory CR in patients with MS-related cognitive impairment. Thirty-four female patients with diagnosed relapsing-remitting MS and evidence of impaired cognitive function were included and randomized to intervention (n = 17) and control (n = 17) groups. CR intervention consisted of eight 2-hour sessions of comprehensive group CR over a 4-week period that focused on improvement of memory, attention, and executive function. As placebo, the control group received the same number of non-therapeutic group sessions. Assessment of cognitive function was performed before intervention (pretest), at the end of intervention (post-test), and 3 months later (follow-up). The study population included 34 patients with a mean age of 35.5 years. Statistical comparison of memory assessments at 3-month follow-up showed significantly higher scores in the CR group than in the control group (93.33 vs 86.40 for Addenbrooke's Cognitive Examination test and 16.58 vs 12.00 for visual memory, 19.32 vs 14.05 for verbal memory, and 51.28 vs 44.41 for general scores on the Memory Functioning Questionnaire test, respectively). Wisconsin card sorting test score comparison showed significantly lower total time consumption in the CR group than in the control group (308.1 vs 340.8 seconds, respectively). Behavior rating inventory of executive function-adult scores in all four subtests were significantly higher in the CR group than in the control group (40.25 vs 55.4 for behavioral regulation index, 51.16 vs 68.6 for metacognition index, and 97.41 vs 124.00 for global executive composite, respectively). Attention was the only domain in which we did not observe any significant variation between groups in terms of post-test and follow-up scores. This study supports the efficacy of group CR in the improvement of cognitive function in patients with MS. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Phylo-VISTA: Interactive visualization of multiple DNA sequence alignments
DOE Office of Scientific and Technical Information (OSTI.GOV)
Shah, Nameeta; Couronne, Olivier; Pennacchio, Len A.
The power of multi-sequence comparison for biological discovery is well established. The need for new capabilities to visualize and compare cross-species alignment data is intensified by the growing number of genomic sequence datasets being generated for an ever-increasing number of organisms. To be efficient these visualization algorithms must support the ability to accommodate consistently a wide range of evolutionary distances in a comparison framework based upon phylogenetic relationships. Results: We have developed Phylo-VISTA, an interactive tool for analyzing multiple alignments by visualizing a similarity measure for multiple DNA sequences. The complexity of visual presentation is effectively organized using a frameworkmore » based upon interspecies phylogenetic relationships. The phylogenetic organization supports rapid, user-guided interspecies comparison. To aid in navigation through large sequence datasets, Phylo-VISTA leverages concepts from VISTA that provide a user with the ability to select and view data at varying resolutions. The combination of multiresolution data visualization and analysis, combined with the phylogenetic framework for interspecies comparison, produces a highly flexible and powerful tool for visual data analysis of multiple sequence alignments. Availability: Phylo-VISTA is available at http://www-gsd.lbl. gov/phylovista. It requires an Internet browser with Java Plugin 1.4.2 and it is integrated into the global alignment program LAGAN at http://lagan.stanford.edu« less
Proof of concept and dose estimation with binary responses under model uncertainty.
Klingenberg, B
2009-01-30
This article suggests a unified framework for testing Proof of Concept (PoC) and estimating a target dose for the benefit of a more comprehensive, robust and powerful analysis in phase II or similar clinical trials. From a pre-specified set of candidate models, we choose the ones that best describe the observed dose-response. To decide which models, if any, significantly pick up a dose effect, we construct the permutation distribution of the minimum P-value over the candidate set. This allows us to find critical values and multiplicity adjusted P-values that control the familywise error rate of declaring any spurious effect in the candidate set as significant. Model averaging is then used to estimate a target dose. Popular single or multiple contrast tests for PoC, such as the Cochran-Armitage, Dunnett or Williams tests, are only optimal for specific dose-response shapes and do not provide target dose estimates with confidence limits. A thorough evaluation and comparison of our approach to these tests reveal that its power is as good or better in detecting a dose-response under various shapes with many more additional benefits: It incorporates model uncertainty in PoC decisions and target dose estimation, yields confidence intervals for target dose estimates and extends to more complicated data structures. We illustrate our method with the analysis of a Phase II clinical trial. Copyright (c) 2008 John Wiley & Sons, Ltd.
Rich, Sandra K; Keim, Robert G; Shuler, Charles F
2005-06-01
To evaluate efficacy of a problem-based learning (PBL) pedagogy in preclinical and clinical teaching, test scores of 234 undergraduate dental students from the conventionally taught classes of 2003 and 2004 were compared with scores of 274 dental students from the PBL classes of 2005 and 2006. Although the groups' means were close together, t-test analysis of scores revealed that PBL students performed significantly better than traditional (TRAD) students on midterm (p=.0001) and final (p=.015) examinations taken on student partner/mock patients. ANOVA comparing the classes with each other showed significant differences for the midterm and final, but not for the clinical examination. Further multiple comparison tests (Tukey HSD) for the midterm and final revealed that differences specifically reflected superior performance of PBL classes against one of the TRAD classes (2004). There was no difference in performance between PBL (n=134) and TRAD (n=233) students on examinations taken with actual clinical patients who were undergoing nonsurgical periodontal treatment. Over a two-year period, PBL students rated their program instructors at a mean of 4.41 on a Likert-type scale of 1 (not helpful) to 5 (outstanding). The program provides a PBL model for teaching preclinical and clinical skills supported by a four-year evaluation of manual skills outcomes.
Benchmarking Procedures for High-Throughput Context Specific Reconstruction Algorithms
Pacheco, Maria P.; Pfau, Thomas; Sauter, Thomas
2016-01-01
Recent progress in high-throughput data acquisition has shifted the focus from data generation to processing and understanding of how to integrate collected information. Context specific reconstruction based on generic genome scale models like ReconX or HMR has the potential to become a diagnostic and treatment tool tailored to the analysis of specific individuals. The respective computational algorithms require a high level of predictive power, robustness and sensitivity. Although multiple context specific reconstruction algorithms were published in the last 10 years, only a fraction of them is suitable for model building based on human high-throughput data. Beside other reasons, this might be due to problems arising from the limitation to only one metabolic target function or arbitrary thresholding. This review describes and analyses common validation methods used for testing model building algorithms. Two major methods can be distinguished: consistency testing and comparison based testing. The first is concerned with robustness against noise, e.g., missing data due to the impossibility to distinguish between the signal and the background of non-specific binding of probes in a microarray experiment, and whether distinct sets of input expressed genes corresponding to i.e., different tissues yield distinct models. The latter covers methods comparing sets of functionalities, comparison with existing networks or additional databases. We test those methods on several available algorithms and deduce properties of these algorithms that can be compared with future developments. The set of tests performed, can therefore serve as a benchmarking procedure for future algorithms. PMID:26834640
NASA Astrophysics Data System (ADS)
Iden, S. C.; Durner, W.; Delay, M.; Frimmel, F. H.
2009-04-01
Contaminated porous materials, like soils, dredged sediments or waste materials must be tested before they can be used as filling materials in order to minimize the risk of groundwater pollution. We applied a multiple batch extraction test at varying liquid-to-solid (L/S) ratios to a demolition waste material and a municipal waste incineration product and investigated the release of chloride, sulphate, sodium, copper, chromium and dissolved organic carbon from both waste materials. The liquid phase test concentrations were used to estimate parameters of a relatively simple mass balance model accounting for equilibrium partitioning. The model parameters were estimated within a Bayesian framework by applying an efficient MCMC sampler and the uncertainties of the model parameters and model predictions were quantified. We tested isotherms of the linear, Freundlich and Langmuir type and selected the optimal isotherm model by use of the Deviance Information Criterion (DIC). Both the excellent fit to the experimental data and a comparison between the model-predicted and independently measured concentrations at the L/S ratios of 0.25 and 0.5 L/kg demonstrate the applicability of the model for almost all studied substances and both waste materials. We conclude that batch extraction tests at varying L/S ratios provide, at moderate experimental cost, a powerful complement to established test designs like column leaching or single batch extraction tests. The method constitutes an important tool in risk assessments, because concentrations at soil water contents representative for the field situation can be predicted from easier-to-obtain test concentrations at larger L/S ratios. This helps to circumvent the experimental difficulties of the soil saturation extract and eliminates the need to apply statistical approaches to predict such representative concentrations which have been shown to suffer dramatically from poor correlations.
The Influence of Counterfactual Comparison on Fairness in Gain-Loss Contexts.
Li, Qi; Wang, Chunsheng; Taxer, Jamie; Yang, Zhong; Zheng, Ya; Liu, Xun
2017-01-01
Fairness perceptions may be affected by counterfactual comparisons. Although certain studies using a two-player ultimatum game (UG) have shown that comparison with the proposers influences the responders' fairness perceptions in a gain context, the effect of counterfactual comparison in a UG with multiple responders or proposers remains unclear, especially in a loss context. To resolve these issues, this study used a modified three-player UG with multiple responders in Experiment 1 and multiple proposers in Experiment 2 to examine the influence of counterfactual comparison on fairness-related decision-making in gain and loss contexts. The two experiments consistently showed that regardless of the gain or loss context, the level of inequality of the offer and counterfactual comparison influenced acceptance rates (ARs), response times (RTs), and fairness ratings (FRs). If the offers that were received were better than the counterfactual offers, unequal offers were more likely to be accepted than equal offers, and participants were more likely to report higher FRs and to make decisions more quickly. In contrast, when the offers they received were worse than the counterfactual offers, participants were more likely to reject unequal offers than equal offers, reported lower FRs, and made decisions more slowly. These results demonstrate that responders' fairness perceptions are influenced by not only comparisons of the absolute amount of money that they would receive but also specific counterfactuals from other proposers or responders. These findings improve our understanding of fairness perceptions.
The Influence of Counterfactual Comparison on Fairness in Gain-Loss Contexts
Li, Qi; Wang, Chunsheng; Taxer, Jamie; Yang, Zhong; Zheng, Ya; Liu, Xun
2017-01-01
Fairness perceptions may be affected by counterfactual comparisons. Although certain studies using a two-player ultimatum game (UG) have shown that comparison with the proposers influences the responders' fairness perceptions in a gain context, the effect of counterfactual comparison in a UG with multiple responders or proposers remains unclear, especially in a loss context. To resolve these issues, this study used a modified three-player UG with multiple responders in Experiment 1 and multiple proposers in Experiment 2 to examine the influence of counterfactual comparison on fairness-related decision-making in gain and loss contexts. The two experiments consistently showed that regardless of the gain or loss context, the level of inequality of the offer and counterfactual comparison influenced acceptance rates (ARs), response times (RTs), and fairness ratings (FRs). If the offers that were received were better than the counterfactual offers, unequal offers were more likely to be accepted than equal offers, and participants were more likely to report higher FRs and to make decisions more quickly. In contrast, when the offers they received were worse than the counterfactual offers, participants were more likely to reject unequal offers than equal offers, reported lower FRs, and made decisions more slowly. These results demonstrate that responders' fairness perceptions are influenced by not only comparisons of the absolute amount of money that they would receive but also specific counterfactuals from other proposers or responders. These findings improve our understanding of fairness perceptions. PMID:28536542
Perception of midline deviations in smile esthetics by laypersons
Ferreira, Jamille Barros; da Silva, Licínio Esmeraldo; Caetano, Márcia Tereza de Oliveira; da Motta, Andrea Fonseca Jardim; Cury-Saramago, Adriana de Alcantara; Mucha, José Nelson
2016-01-01
ABSTRACT Objective: To evaluate the esthetic perception of upper dental midline deviation by laypersons and if adjacent structures influence their judgment. Methods: An album with 12 randomly distributed frontal view photographs of the smile of a woman with the midline digitally deviated was evaluated by 95 laypersons. The frontal view smiling photograph was modified to create from 1 mm to 5 mm deviations in the upper midline to the left side. The photographs were cropped in two different manners and divided into two groups of six photographs each: group LCN included the lips, chin, and two-thirds of the nose, and group L included the lips only. The laypersons performed the rate of each smile using a visual analog scale (VAS). Wilcoxon test, Student’s t-test and Mann-Whitney test were applied, adopting a 5% level of significance. Results: Laypersons were able to perceive midline deviations starting at 1 mm. Statistically significant results (p< 0.05) were found for all multiple comparisons of the values in photographs of group LCN and for almost all comparisons in photographs of group L. Comparisons between the photographs of groups LCN and L showed statistically significant values (p< 0.05) when the deviation was 1 mm. Conclusions: Laypersons were able to perceive the upper dental midline deviations of 1 mm, and above when the adjacent structures of the smiles were included. Deviations of 2 mm and above when the lips only were included. The visualization of structures adjacent to the smile demonstrated influence on the perception of midline deviation. PMID:28125140
Liang, Xiaoyun; Vaughan, David N; Connelly, Alan; Calamante, Fernando
2018-05-01
The conventional way to estimate functional networks is primarily based on Pearson correlation along with classic Fisher Z test. In general, networks are usually calculated at the individual-level and subsequently aggregated to obtain group-level networks. However, such estimated networks are inevitably affected by the inherent large inter-subject variability. A joint graphical model with Stability Selection (JGMSS) method was recently shown to effectively reduce inter-subject variability, mainly caused by confounding variations, by simultaneously estimating individual-level networks from a group. However, its benefits might be compromised when two groups are being compared, given that JGMSS is blinded to other groups when it is applied to estimate networks from a given group. We propose a novel method for robustly estimating networks from two groups by using group-fused multiple graphical-lasso combined with stability selection, named GMGLASS. Specifically, by simultaneously estimating similar within-group networks and between-group difference, it is possible to address inter-subject variability of estimated individual networks inherently related with existing methods such as Fisher Z test, and issues related to JGMSS ignoring between-group information in group comparisons. To evaluate the performance of GMGLASS in terms of a few key network metrics, as well as to compare with JGMSS and Fisher Z test, they are applied to both simulated and in vivo data. As a method aiming for group comparison studies, our study involves two groups for each case, i.e., normal control and patient groups; for in vivo data, we focus on a group of patients with right mesial temporal lobe epilepsy.
Comparison of time-dependent changes in the surface hardness of different composite resins
Ozcan, Suat; Yikilgan, Ihsan; Uctasli, Mine Betul; Bala, Oya; Kurklu, Zeliha Gonca Bek
2013-01-01
Objective: The aim of this study was to evaluate the change in surface hardness of silorane-based composite resin (Filtek Silorane) in time and compare the results with the surface hardness of two methacrylate-based resins (Filtek Supreme and Majesty Posterior). Materials and Methods: From each composite material, 18 wheel-shaped samples (5-mm diameter and 2-mm depth) were prepared. Top and bottom surface hardness of these samples was measured using a Vicker's hardness tester. The samples were then stored at 37°C and 100% humidity. After 24 h and 7, 30 and 90 days, the top and bottom surface hardness of the samples was measured. In each measurement, the rate between the hardness of the top and bottom surfaces were recorded as the hardness rate. Statistical analysis was performed by one-way analysis of variance, multiple comparisons by Tukey's test and binary comparisons by t-test with a significance level of P = 0.05. Results: The highest hardness values were obtained from each two surfaces of Majesty Posterior and the lowest from Filtek Silorane. Both the top and bottom surface hardness of the methacrylate based composite resins was high and there was a statistically significant difference between the top and bottom hardness values of only the silorane-based composite, Filtek Silorane (P < 0.05). The lowest was obtained with Filtek Silorane. The hardness values of all test groups increased after 24 h (P < 0.05). Conclusion: Although silorane-based composite resin Filtek Silorane showed adequate hardness ratio, the use of incremental technic during application is more important than methacrylate based composites. PMID:24966724
Yassen, Ghaeth H; Huang, Ruijie; Al-Zain, Afnan; Yoshida, Takamitsu; Gregory, Richard L; Platt, Jeffrey A
2016-11-01
This study evaluated selected properties of a prototype root repair cement containing surface pre-reacted glass ionomer fillers (S-PRG) in comparison to mineral trioxide aggregate (MTA) and intermediate restorative material (IRM). The antibacterial effect of S-PRG, MTA, and IRM cements was tested against Porphyromonas gingivalis and Enterococcus faecalis after 1 and 3 days of aging of the cements. The set cements were immersed in distilled water for 4 h to 28 days, and ion-releasing ability was evaluated. Initial and final setting times of all cements were evaluated using Gilmore needles. The push-out bond strength between radicular dentin and all cements was tested at different levels of the roots. S-PRG and IRM cements, but not MTA cement, demonstrated significant antibacterial effect against P. gingivalis. All types of cements exhibited significant antibacterial effect against E. faecalis without being able to eliminate the bacterium. S-PRG cement provided continuous release of fluoride, strontium, boron, sodium, aluminum, and zinc throughout all tested time points. Both initial and final setting times were significantly shorter for S-PRG and IRM cements in comparison to MTA. The push-out bond strength was significantly lower for S-PRG cement in comparison to MTA and IRM at coronal and middle levels of the roots. S-PRG cement demonstrated significant antibacterial effects against endodontic pathogens, multiple ion-releasing ability, relatively short setting time, and low bonding strength. S-PRG cement can be used as a one-visit root repair material with promising antibacterial properties and ion-releasing capacity.
Development and evaluation of learning module on clinical decision-making in Prosthodontics.
Deshpande, Saee; Lambade, Dipti; Chahande, Jayashree
2015-01-01
Best practice strategies for helping students learn the reasoning skills of problem solving and critical thinking (CT) remain a source of conjecture, particularly with regard to CT. The dental education literature is fundamentally devoid of research on the cognitive components of clinical decision-making. This study was aimed to develop and evaluate the impact of blended learning module on clinical decision-making skills of dental graduates for planning prosthodontics rehabilitation. An interactive teaching module consisting of didactic lectures on clinical decision-making and a computer-assisted case-based treatment planning software was developed Its impact on cognitive knowledge gain in clinical decision-making was evaluated using an assessment involving problem-based multiple choice questions and paper-based case scenarios. Mean test scores were: Pretest (17 ± 1), posttest 1 (21 ± 2) and posttest 2 (43 ± 3). Comparison of mean scores was done with one-way ANOVA test. There was overall significant difference in between mean scores at all the three points (P < 0.001). A pair-wise comparison of mean scores was done with Bonferroni test. The mean difference is significant at the 0.05 level. The pair-wise comparison shows that posttest 2 score is significantly higher than posttest 1 and posttest 1 is significantly higher than pretest that is, pretest 2 > posttest 1 > pretest. Blended teaching methods employing didactic lectures on the clinical decision-making as well as computer assisted case-based learning can be used to improve quality of clinical decision-making in prosthodontic rehabilitation for dental graduates.
Harrigan, George G; Harrison, Jay M
2012-01-01
New transgenic (GM) crops are subjected to extensive safety assessments that include compositional comparisons with conventional counterparts as a cornerstone of the process. The influence of germplasm, location, environment, and agronomic treatments on compositional variability is, however, often obscured in these pair-wise comparisons. Furthermore, classical statistical significance testing can often provide an incomplete and over-simplified summary of highly responsive variables such as crop composition. In order to more clearly describe the influence of the numerous sources of compositional variation we present an introduction to two alternative but complementary approaches to data analysis and interpretation. These include i) exploratory data analysis (EDA) with its emphasis on visualization and graphics-based approaches and ii) Bayesian statistical methodology that provides easily interpretable and meaningful evaluations of data in terms of probability distributions. The EDA case-studies include analyses of herbicide-tolerant GM soybean and insect-protected GM maize and soybean. Bayesian approaches are presented in an analysis of herbicide-tolerant GM soybean. Advantages of these approaches over classical frequentist significance testing include the more direct interpretation of results in terms of probabilities pertaining to quantities of interest and no confusion over the application of corrections for multiple comparisons. It is concluded that a standardized framework for these methodologies could provide specific advantages through enhanced clarity of presentation and interpretation in comparative assessments of crop composition.
Krumm, Rainer; Dugas, Martin
2016-01-01
Introduction Medical documentation is applied in various settings including patient care and clinical research. Since procedures of medical documentation are heterogeneous and developed further, secondary use of medical data is complicated. Development of medical forms, merging of data from different sources and meta-analyses of different data sets are currently a predominantly manual process and therefore difficult and cumbersome. Available applications to automate these processes are limited. In particular, tools to compare multiple documentation forms are missing. The objective of this work is to design, implement and evaluate the new system ODMSummary for comparison of multiple forms with a high number of semantically annotated data elements and a high level of usability. Methods System requirements are the capability to summarize and compare a set of forms, enable to estimate the documentation effort, track changes in different versions of forms and find comparable items in different forms. Forms are provided in Operational Data Model format with semantic annotations from the Unified Medical Language System. 12 medical experts were invited to participate in a 3-phase evaluation of the tool regarding usability. Results ODMSummary (available at https://odmtoolbox.uni-muenster.de/summary/summary.html) provides a structured overview of multiple forms and their documentation fields. This comparison enables medical experts to assess multiple forms or whole datasets for secondary use. System usability was optimized based on expert feedback. Discussion The evaluation demonstrates that feedback from domain experts is needed to identify usability issues. In conclusion, this work shows that automatic comparison of multiple forms is feasible and the results are usable for medical experts. PMID:27736972
Efficacy of Inactivation of Human Enteroviruses by Multiple ...
Ultraviolet (UV) light has been successfully used for treating a broad suite of pathogens without the concomitant formation of carcinogenic disinfection by-products (DBPs). However, conventional mercury UV lamps have some practical limitations in water treatment applications, such as the inefficiency of energy consumption and more importantly potential mercury contamination upon disposal of the lamps. The recent invention of a novel light-emitting-diodes (LED) device generating germicidal UV wavelengths could eliminate the aforementioned limitations. In this study, we investigated the efficacy of multiple-wavelength UV LEDs for inactivating USEPA contaminant candidate list (CCL) RNA enteroviruses. Of 12 enterovirus species, serotype representatives of the four human enteric species (enterovirus A-D) such as coxsackievirus A10 (CVA10), echovirus 30 (Echo30), poliovirus 1 (PV1), and enterovirus 70 (EV70) respectively were selected as testing RNA viruses. Bench-scale performance evaluation was conducted using a collimated beam (CB) apparatus with LEDs emitting at 260 nm, 280 nm, and the combination of 260|280 nm together, as well as a monochromatic low-pressure (LP) UV lamp at 254 nm for comparison. The CB tests were performed with mixed stocks of four viruses. Infectious virus concentrations were determined using an integrated cell culture reverse transcriptase quantitative PCR (ICC-RTqPCR). The 260 nm LED was most effective at inactivating all enteroviruses teste
Larson-Williams, Linnea M; Youngblood, Amber Q; Peterson, Dawn Taylor; Zinkan, J Lynn; White, Marjorie L; Abdul-Latif, Hussein; Matalka, Leen; Epps, Stephen N; Tofil, Nancy M
2016-01-01
AIM To investigate the use of a multidisciplinary, longitudinal simulation to educate pediatric residents and nurses on management of pediatric diabetic ketoacidosis. METHODS A multidisciplinary, multiple step simulation course was developed by faculty and staff using a modified Delphi method from the Pediatric Simulation Center and pediatric endocrinology department. Effectiveness of the simulation for the residents was measured with a pre- and post-test and a reference group not exposed to simulation. A follow up post-test was completed 3-6 mo after the simulation. Nurses completed a survey regarding the education activity. RESULTS Pediatric and medicine-pediatric residents (n = 20) and pediatric nurses (n = 25) completed the simulation course. Graduating residents (n = 16) were used as reference group. Pretest results were similar in the control and intervention group (74% ± 10% vs 76% ± 15%, P = 0.658). After completing the intervention, participants improved in the immediate post-test in comparison to themselves and the control group (84% ± 12% post study; P < 0.05). The 3-6 mo follow up post-test results demonstrated knowledge decay when compared to their immediate post-test results (78% ± 14%, P = 0.761). Residents and nurses felt the interdisciplinary and longitudinal nature of the simulation helped with learning. CONCLUSION Results suggest a multidisciplinary, longitudinal simulation improves immediate post-intervention knowledge but important knowledge decay occurs, future studies are needed to determine ways to decrease this decay. PMID:27896145
Multiple Hollow Cathode Wear Testing for the Space Station Plasma Contactor
NASA Technical Reports Server (NTRS)
Soulas, George C.
1994-01-01
A wear test of four hollow cathodes was conducted to resolve issues associated with the Space Station plasma contactor. The objectives of this test were to evaluate unit-to-unit dispersions, verify the transportability of contamination control protocols developed by the project, and to evaluate cathode contamination control and activation procedures to enable simplification of the gas feed system and heater power processor. These objectives were achieved by wear testing four cathodes concurrently to 2000 hours. Test results showed maximum unit-to-unit deviations for discharge voltages and cathode tip temperatures to be +/-3 percent and +/-2 percent, respectively, of the nominal values. Cathodes utilizing contamination control procedures known to increase cathode lifetime showed no trends in their monitored parameters that would indicate a possible failure, demonstrating that contamination control procedures had been successfully transferred. Comparisons of cathodes utilizing and not utilizing a purifier or simplified activation procedure showed similar behavior during wear testing and pre- and post-test performance characterizations. This behavior indicates that use of simplified cathode systems and procedures is consistent with long cathode lifetimes.
Rationality in collective decision-making by ant colonies
Edwards, Susan C.; Pratt, Stephen C.
2009-01-01
Economic models of animal behaviour assume that decision-makers are rational, meaning that they assess options according to intrinsic fitness value and not by comparison with available alternatives. This expectation is frequently violated, but the significance of irrational behaviour remains controversial. One possibility is that irrationality arises from cognitive constraints that necessitate short cuts like comparative evaluation. If so, the study of whether and when irrationality occurs can illuminate cognitive mechanisms. We applied this logic in a novel setting: the collective decisions of insect societies. We tested for irrationality in colonies of Temnothorax ants choosing between two nest sites that varied in multiple attributes, such that neither site was clearly superior. In similar situations, individual animals show irrational changes in preference when a third relatively unattractive option is introduced. In contrast, we found no such effect in colonies. We suggest that immunity to irrationality in this case may result from the ants’ decentralized decision mechanism. A colony's choice does not depend on site comparison by individuals, but instead self-organizes from the interactions of multiple ants, most of which are aware of only a single site. This strategy may filter out comparative effects, preventing systematic errors that would otherwise arise from the cognitive limitations of individuals. PMID:19625319
CFD Simulations of the IHF Arc-Jet Flow: Compression-Pad Separation Bolt Wedge Tests
NASA Technical Reports Server (NTRS)
Gokcen, Tahir; Skokova, Kristina A.
2017-01-01
This paper reports computational analyses in support of two wedge tests in a high enthalpy arc-jet facility at NASA Ames Research Center. These tests were conducted using two different wedge models, each placed in a free jet downstream of a corresponding different conical nozzle in the Ames 60-MW Interaction Heating Facility. Each panel test article included a metallic separation bolt imbedded in Orion compression-pad and heatshield materials, resulting in a circular protuberance over a flat plate. The protuberances produce complex model flowfields, containing shock-shock and shock-boundary layer interactions, and multiple augmented heating regions on the test plate. As part of the test calibration runs, surface pressure and heat flux measurements on water-cooled calibration plates integrated with the wedge models were also obtained. Surface heating distributions on the test articles as well as arc-jet test environment parameters for each test configuration are obtained through computational fluid dynamics simulations, consistent with the facility and calibration measurements. The present analysis comprises simulations of the non-equilibrium flow field in the facility nozzle, test box, and flow field over test articles, and comparisons with the measured calibration data.
CFD Simulations of the IHF Arc-Jet Flow: Compression-Pad/Separation Bolt Wedge Tests
NASA Technical Reports Server (NTRS)
Goekcen, Tahir; Skokova, Kristina A.
2017-01-01
This paper reports computational analyses in support of two wedge tests in a high enthalpy arc-jet facility at NASA Ames Research Center. These tests were conducted using two different wedge models, each placed in a free jet downstream of a corresponding different conical nozzle in the Ames 60-MW Interaction Heating Facility. Each panel test article included a metallic separation bolt imbedded in Orion compression-pad and heatshield materials, resulting in a circular protuberance over a flat plate. The protuberances produce complex model flowfields, containing shock-shock and shock-boundary layer interactions, and multiple augmented heating regions on the test plate. As part of the test calibration runs, surface pressure and heat flux measurements on water-cooled calibration plates integrated with the wedge models were also obtained. Surface heating distributions on the test articles as well as arc-jet test environment parameters for each test configuration are obtained through computational fluid dynamics simulations, consistent with the facility and calibration measurements. The present analysis comprises simulations of the nonequilibrium flowfield in the facility nozzle, test box, and flowfield over test articles, and comparisons with the measured calibration data.
Yamano, Tetsuo; Shimizu, Mitsuru; Noda, Tsutomu
2005-07-01
We compared the results of the multiple-dose guinea pig maximization test (GPMT) and the non-radioactive murine local lymph-node assay (LLNA) for various biocides. Thirteen out of 17 positive biocides in the GPMT gave positive results in the LLNA. In the GPMT, the minimum first induction doses ranged over four orders (0.00005-0.5%), while elicitation-threshold doses, which were evaluated using an optimally sensitized group of animals in the multiple-dose studies, ranged over five orders (0.00006-2.8%). In the LLNA, minimum induction doses ranged over more than three orders (0.01-30%). With respect to 13 biocides that were positive in both the GPMT and the LLNA, results were quantitatively compared. When compared after conversion to corresponding area doses (microg/cm), the minimum doses required to elicit skin reaction in guinea pigs were always lower than that for induction in mice with all biocides. Correlation between minimum induction doses from the GPMT and the LLNA seemed poor (r=0.57), while that between minimum induction doses in the LLNA and elicitation-threshold doses in the GPMT was relatively good (r=0.73). The results suggest the possibility to estimate human elicitation-threshold doses, which are definitely lacking in the process of risk assessment for skin-sensitizers, from the data of the LLNA.
Evaluation and Field Assessment of Bifacial Photovoltaic Module Power Rating Methodologies
DOE Office of Scientific and Technical Information (OSTI.GOV)
Deline, Chris; MacAlpine, Sara; Marion, Bill
2016-11-21
1-sun power ratings for bifacial modules are currently undefined. This is partly because there is no standard definition of rear irradiance given 1000 Wm-2 on the front. Using field measurements and simulations, we evaluate multiple deployment scenarios for bifacial modules and provide details on the amount of irradiance that could be expected. A simplified case that represents a single module deployed under conditions consistent with existing 1-sun irradiance standards leads to a bifacial reference condition of 1000 Wm-2 Gfront and 130-140 Wm-2 Grear. For fielded systems of bifacial modules, Grear magnitude and spatial uniformity will be affected by self-shade frommore » adjacent modules, varied ground cover, and ground-clearance height. A standard measurement procedure for bifacial modules is also currently undefined. A proposed international standard is under development, which provides the motivation for this work. Here, we compare outdoor field measurements of bifacial modules with irradiance on both sides with proposed indoor test methods where irradiance is only applied to one side at a time. The indoor method has multiple advantages, including controlled and repeatable irradiance and thermal environment, along with allowing the use of conventional single-sided flash test equipment. The comparison results are promising, showing that the indoor and outdoor methods agree within 1%-2% for multiple rear-irradiance conditions and bifacial module types.« less
Evaluation and Field Assessment of Bifacial Photovoltaic Module Power Rating Methodologies: Preprint
DOE Office of Scientific and Technical Information (OSTI.GOV)
Deline, Chris; MacAlpine, Sara; Marion, Bill
2016-06-16
1-sun power ratings for bifacial modules are currently undefined. This is partly because there is no standard definition of rear irradiance given 1000 Wm-2 on the front. Using field measurements and simulations, we evaluate multiple deployment scenarios for bifacial modules and provide details on the amount of irradiance that could be expected. A simplified case that represents a single module deployed under conditions consistent with existing 1-sun irradiance standards leads to a bifacial reference condition of 1000 Wm-2 Gfront and 130-140 Wm-2 Grear. For fielded systems of bifacial modules, Grear magnitude and spatial uniformity will be affected by self-shade frommore » adjacent modules, varied ground cover, and ground-clearance height. A standard measurement procedure for bifacial modules is also currently undefined. A proposed international standard is under development, which provides the motivation for this work. Here, we compare outdoor field measurements of bifacial modules with irradiance on both sides with proposed indoor test methods where irradiance is only applied to one side at a time. The indoor method has multiple advantages, including controlled and repeatable irradiance and thermal environment, along with allowing the use of conventional single-sided flash test equipment. The comparison results are promising, showing that the indoor and outdoor methods agree within 1%-2% for multiple rear-irradiance conditions and bifacial module types.« less
Longitudinal Multiple Sclerosis Lesion Segmentation: Resource & Challenge
Carass, Aaron; Roy, Snehashis; Jog, Amod; Cuzzocreo, Jennifer L.; Magrath, Elizabeth; Gherman, Adrian; Button, Julia; Nguyen, James; Prados, Ferran; Sudre, Carole H.; Cardoso, Manuel Jorge; Cawley, Niamh; Ciccarelli, Olga; Wheeler-Kingshott, Claudia A. M.; Ourselin, Sébastien; Catanese, Laurence; Deshpande, Hrishikesh; Maurel, Pierre; Commowick, Olivier; Barillot, Christian; Tomas-Fernandez, Xavier; Warfield, Simon K.; Vaidya, Suthirth; Chunduru, Abhijith; Muthuganapathy, Ramanathan; Krishnamurthi, Ganapathy; Jesson, Andrew; Arbel, Tal; Maier, Oskar; Handels, Heinz; Iheme, Leonardo O.; Unay, Devrim; Jain, Saurabh; Sima, Diana M.; Smeets, Dirk; Ghafoorian, Mohsen; Platel, Bram; Birenbaum, Ariel; Greenspan, Hayit; Bazin, Pierre-Louis; Calabresi, Peter A.; Crainiceanu, Ciprian M.; Ellingsen, Lotta M.; Reich, Daniel S.; Prince, Jerry L.; Pham, Dzung L.
2017-01-01
In conjunction with the ISBI 2015 conference, we organized a longitudinal lesion segmentation challenge providing training and test data to registered participants. The training data consisted of five subjects with a mean of 4.4 time-points, and test data of fourteen subjects with a mean of 4.4 time-points. All 82 data sets had the white matter lesions associated with multiple sclerosis delineated by two human expert raters. Eleven teams submitted results using state-of-the-art lesion segmentation algorithms to the challenge, with ten teams presenting their results at the conference. We present a quantitative evaluation comparing the consistency of the two raters as well as exploring the performance of the eleven submitted results in addition to three other lesion segmentation algorithms. The challenge presented three unique opportunities: 1) the sharing of a rich data set; 2) collaboration and comparison of the various avenues of research being pursued in the community; and 3) a review and refinement of the evaluation metrics currently in use. We report on the performance of the challenge participants, as well as the construction and evaluation of a consensus delineation. The image data and manual delineations will continue to be available for download, through an evaluation website1 as a resource for future researchers in the area. This data resource provides a platform to compare existing methods in a fair and consistent manner to each other and multiple manual raters. PMID:28087490
Multiple-frequency continuous wave ultrasonic system for accurate distance measurement
NASA Astrophysics Data System (ADS)
Huang, C. F.; Young, M. S.; Li, Y. C.
1999-02-01
A highly accurate multiple-frequency continuous wave ultrasonic range-measuring system for use in air is described. The proposed system uses a method heretofore applied to radio frequency distance measurement but not to air-based ultrasonic systems. The method presented here is based upon the comparative phase shifts generated by three continuous ultrasonic waves of different but closely spaced frequencies. In the test embodiment to confirm concept feasibility, two low cost 40 kHz ultrasonic transducers are set face to face and used to transmit and receive ultrasound. Individual frequencies are transmitted serially, each generating its own phase shift. For any given frequency, the transmitter/receiver distance modulates the phase shift between the transmitted and received signals. Comparison of the phase shifts allows a highly accurate evaluation of target distance. A single-chip microcomputer-based multiple-frequency continuous wave generator and phase detector was designed to record and compute the phase shift information and the resulting distance, which is then sent to either a LCD or a PC. The PC is necessary only for calibration of the system, which can be run independently after calibration. Experiments were conducted to test the performance of the whole system. Experimentally, ranging accuracy was found to be within ±0.05 mm, with a range of over 1.5 m. The main advantages of this ultrasonic range measurement system are high resolution, low cost, narrow bandwidth requirements, and ease of implementation.
Koerner, Tess K.; Zhang, Yang
2017-01-01
Neurophysiological studies are often designed to examine relationships between measures from different testing conditions, time points, or analysis techniques within the same group of participants. Appropriate statistical techniques that can take into account repeated measures and multivariate predictor variables are integral and essential to successful data analysis and interpretation. This work implements and compares conventional Pearson correlations and linear mixed-effects (LME) regression models using data from two recently published auditory electrophysiology studies. For the specific research questions in both studies, the Pearson correlation test is inappropriate for determining strengths between the behavioral responses for speech-in-noise recognition and the multiple neurophysiological measures as the neural responses across listening conditions were simply treated as independent measures. In contrast, the LME models allow a systematic approach to incorporate both fixed-effect and random-effect terms to deal with the categorical grouping factor of listening conditions, between-subject baseline differences in the multiple measures, and the correlational structure among the predictor variables. Together, the comparative data demonstrate the advantages as well as the necessity to apply mixed-effects models to properly account for the built-in relationships among the multiple predictor variables, which has important implications for proper statistical modeling and interpretation of human behavior in terms of neural correlates and biomarkers. PMID:28264422
Matthews, Luke J.; Tehrani, Jamie J.; Jordan, Fiona M.; Collard, Mark; Nunn, Charles L.
2011-01-01
Background Archaeologists and anthropologists have long recognized that different cultural complexes may have distinct descent histories, but they have lacked analytical techniques capable of easily identifying such incongruence. Here, we show how Bayesian phylogenetic analysis can be used to identify incongruent cultural histories. We employ the approach to investigate Iranian tribal textile traditions. Methods We used Bayes factor comparisons in a phylogenetic framework to test two models of cultural evolution: the hierarchically integrated system hypothesis and the multiple coherent units hypothesis. In the hierarchically integrated system hypothesis, a core tradition of characters evolves through descent with modification and characters peripheral to the core are exchanged among contemporaneous populations. In the multiple coherent units hypothesis, a core tradition does not exist. Rather, there are several cultural units consisting of sets of characters that have different histories of descent. Results For the Iranian textiles, the Bayesian phylogenetic analyses supported the multiple coherent units hypothesis over the hierarchically integrated system hypothesis. Our analyses suggest that pile-weave designs represent a distinct cultural unit that has a different phylogenetic history compared to other textile characters. Conclusions The results from the Iranian textiles are consistent with the available ethnographic evidence, which suggests that the commercial rug market has influenced pile-rug designs but not the techniques or designs incorporated in the other textiles produced by the tribes. We anticipate that Bayesian phylogenetic tests for inferring cultural units will be of great value for researchers interested in studying the evolution of cultural traits including language, behavior, and material culture. PMID:21559083
Humblet, Olivier; Korrick, Susan A; Williams, Paige L; Sergeyev, Oleg; Emond, Claude; Birnbaum, Linda S; Burns, Jane S; Altshul, Larisa M; Patterson, Donald G; Turner, Wayman E; Lee, Mary M; Revich, Boris; Hauser, Russ
2013-01-01
Exposure to dioxins has been associated with delayed pubertal onset in both epidemiologic and animal studies. Whether genetic polymorphisms may modify this association is currently unknown. Identifying such genes could provide insight into mechanistic pathways. This is one of the first studies to assess genetic susceptibility to dioxins. We evaluated whether common polymorphisms in genes affecting either molecular responses to dioxin exposure or pubertal onset influence the association between peripubertal serum dioxin concentration and male pubertal onset. In this prospective cohort of Russian adolescent boys (n = 392), we assessed gene-environment interactions for 337 tagging single-nucleotide polymorphisms (SNPs) from 46 candidate genes and two intergenic regions. Dioxins were measured in the boys' serum at age 8-9 years. Pubertal onset was based on testicular volume and on genitalia staging. Statistical approaches for controlling for multiple testing were used, both with and without prescreening for marginal genetic associations. After accounting for multiple testing, two tag SNPs in the glucocorticoid receptor (GR/NR3C1) gene and one in the estrogen receptor-α (ESR1) gene were significant (q < 0.2) modifiers of the association between peripubertal serum dioxin concentration and male pubertal onset defined by genitalia staging, although not by testicular volume. The results were sensitive to whether multiple comparison adjustment was applied to all gene-environment tests or only to those with marginal genetic associations. Common genetic polymorphisms in the glucocorticoid receptor and estrogen receptor-α genes may modify the association between peripubertal serum dioxin concentration and pubertal onset. Further studies are warranted to confirm these findings.
Benchmarking in pathology: development of an activity-based costing model.
Burnett, Leslie; Wilson, Roger; Pfeffer, Sally; Lowry, John
2012-12-01
Benchmarking in Pathology (BiP) allows pathology laboratories to determine the unit cost of all laboratory tests and procedures, and also provides organisational productivity indices allowing comparisons of performance with other BiP participants. We describe 14 years of progressive enhancement to a BiP program, including the implementation of 'avoidable costs' as the accounting basis for allocation of costs rather than previous approaches using 'total costs'. A hierarchical tree-structured activity-based costing model distributes 'avoidable costs' attributable to the pathology activities component of a pathology laboratory operation. The hierarchical tree model permits costs to be allocated across multiple laboratory sites and organisational structures. This has enabled benchmarking on a number of levels, including test profiles and non-testing related workload activities. The development of methods for dealing with variable cost inputs, allocation of indirect costs using imputation techniques, panels of tests, and blood-bank record keeping, have been successfully integrated into the costing model. A variety of laboratory management reports are produced, including the 'cost per test' of each pathology 'test' output. Benchmarking comparisons may be undertaken at any and all of the 'cost per test' and 'cost per Benchmarking Complexity Unit' level, 'discipline/department' (sub-specialty) level, or overall laboratory/site and organisational levels. We have completed development of a national BiP program. An activity-based costing methodology based on avoidable costs overcomes many problems of previous benchmarking studies based on total costs. The use of benchmarking complexity adjustment permits correction for varying test-mix and diagnostic complexity between laboratories. Use of iterative communication strategies with program participants can overcome many obstacles and lead to innovations.
Comparison of CAM-Chem with Trace Gas Measurements from Airborne Field Campaigns from 2009-2016.
NASA Astrophysics Data System (ADS)
Schauffler, S.; Atlas, E. L.; Kinnison, D. E.; Lamarque, J. F.; Saiz-Lopez, A.; Navarro, M. A.; Donets, V.; Blake, D. R.; Blake, N. J.
2016-12-01
Trace gas measurements collected during seven field campaigns, two with multiple deployments, will be compared with the NCAR CAM-Chem model to evaluate the model performance over multiple years. The campaigns include HIPPO (2009-2011) pole to pole observations in the Pacific on the NSF/NCAR GV over multiple seasons; SEAC4RS (Aug./Sept., 2013) in the central and southern U.S. and western Gulf of Mexico on the NASA ER-2 and DC8; ATTREX (2011-2015) on the NASA Global Hawk over multiple seasons and locations; CONTRAST (Jan/Feb, 2014) in the western Pacific on the NSF/NCAR GV; VIRGAS (Oct., 2015) in the south central US and western Gulf of Mexico on the NASA WB-57; ORCAS (Jan/Feb, 2016) over the southern ocean on the NSF/NCAR GV; and POSIDON (Oct, 2016) in the western Pacific on the NASA WB-57. We will focus on along the flight tracks comparisons with the model and will also examine comparisons of vertical distributions and various tracer-tracer correlations.
Comparison of 3 kidney injury multiplex panels in rats.
John-Baptiste, Annette; Vitsky, Allison; Sace, Frederick; Zong, Qing; Ko, Mira; Yafawi, Rolla; Liu, Ling
2012-01-01
Kidney injury biomarkers have been utilized by pharmaceutical companies as a means to assess the potential of candidate drugs to induce nephrotoxicity. Multiple platforms and assay methods exist, but the comparison of these methods has not been described. Millipore's Kidney Toxicity panel, EMD/Novagen's Widescreen Kidney Toxicity panel, and Meso Scales Kidney Injury panel were selected based on published information. Kidney injury molecule 1, cystatin C, clusterin, and osteopontin were the 4 biomarkers common among all kits tested and the focus of this study. Rats were treated with a low and high dose of para-aminophenol, a known nephrotoxicant, and urine samples were collected and analyzed on the Bio-Plex 200 or MSD's Sector Imager 6000, according to manufacturers specifications. Comparatively, of the 3 kits, Millipore was the most consistent in detecting elevations of 3 out of the 4 biomarkers at both dose levels and indicated time points.
CCD Photometry of bright stars using objective wire mesh
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kamiński, Krzysztof; Zgórz, Marika; Schwarzenberg-Czerny, Aleksander, E-mail: chrisk@amu.edu.pl
2014-06-01
Obtaining accurate photometry of bright stars from the ground remains problematic due to the danger of overexposing the target and/or the lack of suitable nearby comparison stars. The century-old method of using objective wire mesh to produce multiple stellar images seems promising for the precise CCD photometry of such stars. Furthermore, our tests on β Cep and its comparison star, differing by 5 mag, are very encouraging. Using a CCD camera and a 20 cm telescope with the objective covered by a plastic wire mesh, in poor weather conditions, we obtained differential photometry with a precision of 4.5 mmag permore » two minute exposure. Our technique is flexible and may be tuned to cover a range as big as 6-8 mag. We discuss the possibility of installing a wire mesh directly in the filter wheel.« less
Clinical and Functional Outcome of Childhood ADHD 33 Years Later
Klein, Rachel G.; Mannuzza, Salvatore; Ramos Olazagasti, María A.; Roizen Belsky, Erica; Hutchison, Jesse A.; Lashua-Shriftman, Erin; Castellanos, F. Xavier
2012-01-01
Context Prospective studies of childhood attention deficit/hyperactivity disorder (ADHD) have not extended beyond early adulthood. Objective To test whether children diagnosed with ADHD at mean age 8 (probands) have worse educational, occupational, economic, social, marital outcomes; higher rates of ongoing ADHD, antisocial personality disorder (ASPD), substance disorders (SD); adult onset psychiatric disorders, psychiatric hospitalizations and incarcerations, than non-ADHD comparisons, at mean age 41. To test for: positive associations between probands’ ongoing ADHD and ASPD, and SD’s; and for worse social and occupational functioning in probands without ongoing psychiatric disorders, than comparisons. Design Prospective, 33 year follow-up study, with blind clinical assessments. Setting Research clinic. Participants 135 Caucasian males with ADHD in childhood, free of conduct disorder, and 136 male comparisons without childhood ADHD (65% and 76% of original cohort, respectively). Main Outcome Measures Occupational, economic, and educational attainment; marital history; occupational and social functioning; ongoing and lifetime psychiatric disorders; psychiatric hospitalizations, and incarcerations. Results Probands had significantly worse educational, occupational, economic, social outcomes, and more divorces than comparisons; higher rates of ongoing ADHD (22% vs 5%, p<.001), ASPD (16% vs 0%, p<.001)and SD (14% vs 5%, p<.01), but not more mood or anxiety disorders (p’s=.36 and .33). Ongoing ADHD was weakly related to ongoing SD (phi=.19, p=.04), and ASPD+SD (phi=.20, p=.04). Lifetime, probands had significantly more ASPD and SD’s, but not mood or anxiety disorders, and more psychiatric hospitalizations and incarcerations than comparisons. Relative to comparisons, psychiatric disorders with onsets at age 21 or beyond were not significantly elevated in probands. Probands without ongoing psychiatric disorders had worse social, but not occupational, functioning. Conclusions The multiple disadvantages predicted by childhood ADHD well into adulthood began in adolescence, without increased onsets of new disorders after age 20. Findings highlight the importance of extended monitoring and treatment of children with ADHD. PMID:23070149
NASA Technical Reports Server (NTRS)
Baumgardner, M. F. (Principal Investigator)
1974-01-01
The author has identified the following significant results. Multispectral scanner data obtained by ERTS-1 over six test sites in the Central United States were analyzed and interpreted. ERTS-1 data for some of the test sites were geometrically corrected and temporally overlayed. Computer-implemented pattern recognition techniques were used in the analysis of all multispectral data. These techniques were used to evaluate ERTS-1 data as a tool for soil survey. Geology maps and land use inventories were prepared by digital analysis of multispectral data. Identification and mapping of crop species and rangelands were achieved throught the analysis of 1972 and 1973 ERTS-1 data. Multiple dates of ERTS-1 data were examined to determine the variation with time of the areal extent of surface water resources on the Southern Great Plain.
The Multidimensional Assessment of Interoceptive Awareness (MAIA)
Mehling, Wolf E.; Price, Cynthia; Daubenmier, Jennifer J.; Acree, Mike; Bartmess, Elizabeth; Stewart, Anita
2012-01-01
This paper describes the development of a multidimensional self-report measure of interoceptive body awareness. The systematic mixed-methods process involved reviewing the current literature, specifying a multidimensional conceptual framework, evaluating prior instruments, developing items, and analyzing focus group responses to scale items by instructors and patients of body awareness-enhancing therapies. Following refinement by cognitive testing, items were field-tested in students and instructors of mind-body approaches. Final item selection was achieved by submitting the field test data to an iterative process using multiple validation methods, including exploratory cluster and confirmatory factor analyses, comparison between known groups, and correlations with established measures of related constructs. The resulting 32-item multidimensional instrument assesses eight concepts. The psychometric properties of these final scales suggest that the Multidimensional Assessment of Interoceptive Awareness (MAIA) may serve as a starting point for research and further collaborative refinement. PMID:23133619
Improvements To Progressive Wave Tube Performance Through Closed-Loop Control
NASA Technical Reports Server (NTRS)
Rizzi, Stephen A.
2000-01-01
This report documents recent improvements to the acoustic and thermal control systems of the Thermal Acoustic Fatigue Apparatus (TAFA), a progressive wave tube test facility at the NASA Langley Research Center, Hampton, Virginia. A brief summary of past acoustic performance is given first to serve as a basis for comparison with the new performance data using a multiple-input, closed-loop, narrow-band controller. Performance data in the form of test section acoustic power spectral densities and coherence are presented in three of six facility configurations for a variety of input spectra. Tested spectra include uniform, two cases of pink noise, three cases of narrow-band random, a simulated launch payload bay environment for an expendable launch vehicle, and a simulated external acoustic load for the aft section of a reusable launch vehicle. In addition, a new closed-loop temperature controller and thermocouple data acquisition system are described.
Near-field measurement facility plans at Lewis Research Center
NASA Technical Reports Server (NTRS)
Sharp, R. G.
1983-01-01
The direction of future antenna technology will be toward antennas which are large, both physically and electrically, will operate at frequencies up to 60 GHz, and are non-reciprocal and complex, implementing multiple-beam and scanning beam concepts and monolithic semiconductor devices and techniques. The acquisition of accurate antenna performance measurements is a critical part of the advanced antenna research program and represents a substantial antenna measurement technology challenge, considering the special characteristics of future spacecraft communications antennas. Comparison of various antenna testing techniques and their relative advantages and disadvantages shows that the near-field approach is necessary to meet immediate and long-term testing requirements. The LeRC facilities, the 22 ft x 22 ft horizontal antenna boresight planar scanner and the 60 ft x 60 ft vertical antenna boresight plant scanner (with a 60 GHz frequency and D/lamdba = 3000 electrical size capabilities), will meet future program testing requirements.
Seismic imaging of post-glacial sediments - test study before Spitsbergen expedition
NASA Astrophysics Data System (ADS)
Szalas, Joanna; Grzyb, Jaroslaw; Majdanski, Mariusz
2017-04-01
This work presents results of the analysis of reflection seismic data acquired from testing area in central Poland. For this experiment we used total number of 147 vertical component seismic stations (DATA-CUBE and Reftek "Texan") with accelerated weight drop (PEG-40). The profile was 350 metres long. It is a part of pilot study for future research project on Spitsbergen. The purpose of the study is to recognise the characteristics of seismic response of post-glacial sediments in order to design the most adequate survey acquisition parameters and processing sequence for data from Spitsbergen. Multiple tests and comparisons have been performed to obtain the best possible quality of seismic image. In this research we examine the influence of receiver interval size, front mute application and surface wave attenuation attempts. Although seismic imaging is the main technique we are planning to support this analysis with additional data from traveltime tomography, MASW and other a priori information.
Lucht, Michael J; Barnow, Sven; Sonnenfeld, Christine; Ulrich, Ines; Grabe, Hans Joergen; Schroeder, Winnie; Völzke, Henry; Freyberger, Harald J; John, Ulrich; Herrmann, Falko H; Kroemer, Heyo; Rosskopf, Dieter
2013-02-01
The application of intranasal oxytocin enhances facial emotion recognition in normal subjects and in subjects with autism spectrum disorders (ASD). In addition, various features of social cognition have been associated with variants of the oxytocin receptor gene (OXTR). Therefore, we tested for associations between mind-reading, a measure for social recognition and OXTR polymorphisms. 76 healthy adolescents and young adults were tested for associations between OXTR rs53576, rs2254298, rs2228485 and mind-reading using the "Reading the Mind in the Eyes Test" (RMET). After Bonferroni correction for multiple comparisons, rs2228485 was associated with the number of incorrect answers when subjects evaluated male faces (P =0.000639). There were also associations between OXTR rs53576, rs2254298 and rs2228485 and other RMET dimensions according to P <0.05 (uncorrected). This study adds further evidence to the hypothesis that genetic variations in the OXTR modulate mind-reading and social behaviour.
Impaired consciousness in partial seizures is bimodally distributed
Cunningham, Courtney; Chen, William C.; Shorten, Andrew; McClurkin, Michael; Choezom, Tenzin; Schmidt, Christian P.; Chu, Victoria; Bozik, Anne; Best, Cameron; Chapman, Melissa; Furman, Moran; Detyniecki, Kamil; Giacino, Joseph T.
2014-01-01
Objective: To investigate whether impaired consciousness in partial seizures can usually be attributed to specific deficits in the content of consciousness or to a more general decrease in the overall level of consciousness. Methods: Prospective testing during partial seizures was performed in patients with epilepsy using the Responsiveness in Epilepsy Scale (n = 83 partial seizures, 30 patients). Results were compared with responsiveness scores in a cohort of patients with severe traumatic brain injury evaluated with the JFK Coma Recovery Scale–Revised (n = 552 test administrations, 184 patients). Results: Standardized testing during partial seizures reveals a bimodal scoring distribution, such that most patients were either fully impaired or relatively spared in their ability to respond on multiple cognitive tests. Seizures with impaired performance on initial test items remained consistently impaired on subsequent items, while other seizures showed spared performance throughout. In the comparison group, we found that scores of patients with brain injury were more evenly distributed across the full range in severity of impairment. Conclusions: Partial seizures can often be cleanly separated into those with vs without overall impaired responsiveness. Results from similar testing in a comparison group of patients with brain injury suggest that the bimodal nature of Responsiveness in Epilepsy Scale scores is not a result of scale bias but may be a finding unique to partial seizures. These findings support a model in which seizures either propagate or do not propagate to key structures that regulate overall arousal and thalamocortical function. Future investigations are needed to relate these behavioral findings to the physiology underlying impaired consciousness in partial seizures. PMID:24727311
Impaired consciousness in partial seizures is bimodally distributed.
Cunningham, Courtney; Chen, William C; Shorten, Andrew; McClurkin, Michael; Choezom, Tenzin; Schmidt, Christian P; Chu, Victoria; Bozik, Anne; Best, Cameron; Chapman, Melissa; Furman, Moran; Detyniecki, Kamil; Giacino, Joseph T; Blumenfeld, Hal
2014-05-13
To investigate whether impaired consciousness in partial seizures can usually be attributed to specific deficits in the content of consciousness or to a more general decrease in the overall level of consciousness. Prospective testing during partial seizures was performed in patients with epilepsy using the Responsiveness in Epilepsy Scale (n = 83 partial seizures, 30 patients). Results were compared with responsiveness scores in a cohort of patients with severe traumatic brain injury evaluated with the JFK Coma Recovery Scale-Revised (n = 552 test administrations, 184 patients). Standardized testing during partial seizures reveals a bimodal scoring distribution, such that most patients were either fully impaired or relatively spared in their ability to respond on multiple cognitive tests. Seizures with impaired performance on initial test items remained consistently impaired on subsequent items, while other seizures showed spared performance throughout. In the comparison group, we found that scores of patients with brain injury were more evenly distributed across the full range in severity of impairment. Partial seizures can often be cleanly separated into those with vs without overall impaired responsiveness. Results from similar testing in a comparison group of patients with brain injury suggest that the bimodal nature of Responsiveness in Epilepsy Scale scores is not a result of scale bias but may be a finding unique to partial seizures. These findings support a model in which seizures either propagate or do not propagate to key structures that regulate overall arousal and thalamocortical function. Future investigations are needed to relate these behavioral findings to the physiology underlying impaired consciousness in partial seizures.
Lopes, Hélio P; Gambarra-Soares, Thaiane; Elias, Carlos N; Siqueira, José F; Inojosa, Inês F J; Lopes, Weber S P; Vieira, Victor T L
2013-04-01
This study compared the mechanical properties of endodontic instruments made of conventional nickel-titanium (NiTi) wire (K(3) and Revo-S SU), M-Wire (ProFile Vortex), or NiTi alloy in R-phase (K(3)XF). The test instruments were subjected to mechanical tests to evaluate resistance to bending (flexibility), cyclic fatigue, and torsional load in clockwise rotation. Data were statistically evaluated by the analysis of variance test and the Student-Newman-Keuls test for multiple comparisons. In the bending resistance test, flexibility decreased in the following order: K(3)XF > Revo-S SU > ProFile Vortex > K(3). The ranking in the fatigue resistance test was the following: K(3)XF > K(3) > ProFile Vortex > Revo-S SU. In the torsional assay, the angular deflection at failure decreased in the following order: K(3)XF > Revo-S SU > K(3) > ProFile Vortex. For the maximum torque values, the ranking was K(3) > K(3)XF > ProFile Vortex > Revo-S SU. The results showed that the K(3)XF instrument, which is made of NiTi alloy in R-phase, had the overall best performance in terms of flexibility, angular deflection at failure, and cyclic fatigue resistance. In addition to the alloy from which the instrument is manufactured, the design and dimensions are important determinants of the mechanical performance of endodontic instruments. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.
Multi-Exciter Vibroacoustic Simulation of Hypersonic Flight Vibration
DOE Office of Scientific and Technical Information (OSTI.GOV)
GREGORY,DANNY LYNN; CAP,JEROME S.; TOGAMI,THOMAS C.
1999-11-11
Many aerospace structures must survive severe high frequency, hypersonic, random vibration during their flights. The random vibrations are generated by the turbulent boundary layer developed along the exterior of the structures during flight. These environments have not been simulated very well in the past using a fixed-based, single exciter input with an upper frequency range of 2 kHz. This study investigates the possibility of using acoustic ardor independently controlled multiple exciters to more accurately simulate hypersonic flight vibration. The test configuration, equipment, and methodology are described. Comparisons with actual flight measurements and previous single exciter simulations are also presented.
TreeQ-VISTA: An Interactive Tree Visualization Tool withFunctional Annotation Query Capabilities
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gu, Shengyin; Anderson, Iain; Kunin, Victor
2007-05-07
Summary: We describe a general multiplatform exploratorytool called TreeQ-Vista, designed for presenting functional annotationsin a phylogenetic context. Traits, such as phenotypic and genomicproperties, are interactively queried from a relational database with auser-friendly interface which provides a set of tools for users with orwithout SQL knowledge. The query results are projected onto aphylogenetic tree and can be displayed in multiple color groups. A richset of browsing, grouping and query tools are provided to facilitatetrait exploration, comparison and analysis.Availability: The program,detailed tutorial and examples are available online athttp://genome-test.lbl.gov/vista/TreeQVista.
Development of flight experiments for remote measurement of pollution
NASA Technical Reports Server (NTRS)
Keafer, L. S., Jr.; Kopia, L. P.
1973-01-01
The status as of February 1973 of several NASA-sponsored development projects is reported concerning flight experiments for remote measurement of pollution. Eight passive multispectral instruments for remotely sensing air and water pollutants are described, as well as two active (laser radar) measuring techniques. These techniques are expected to add some new dimensions to the remote sensing of water quality, oceanographic parameters, and earth resources. Multiple applications in these fields are generally possible. Successful completion of the flight demonstration tests and comparisons with simultaneously obtained surface truth measurements may establish these techniques as valid water quality monitoring tools.
McCaffrey, Nikki; Agar, Meera; Harlum, Janeane; Karnon, Jonathon; Currow, David; Eckermann, Simon
2015-01-01
Introduction Comparing multiple, diverse outcomes with cost-effectiveness analysis (CEA) is important, yet challenging in areas like palliative care where domains are unamenable to integration with survival. Generic multi-attribute utility values exclude important domains and non-health outcomes, while partial analyses—where outcomes are considered separately, with their joint relationship under uncertainty ignored—lead to incorrect inference regarding preferred strategies. Objective The objective of this paper is to consider whether such decision making can be better informed with alternative presentation and summary measures, extending methods previously shown to have advantages in multiple strategy comparison. Methods Multiple outcomes CEA of a home-based palliative care model (PEACH) relative to usual care is undertaken in cost disutility (CDU) space and compared with analysis on the cost-effectiveness plane. Summary measures developed for comparing strategies across potential threshold values for multiple outcomes include: expected net loss (ENL) planes quantifying differences in expected net benefit; the ENL contour identifying preferred strategies minimising ENL and their expected value of perfect information; and cost-effectiveness acceptability planes showing probability of strategies minimising ENL. Results Conventional analysis suggests PEACH is cost-effective when the threshold value per additional day at home ( 1) exceeds $1,068 or dominated by usual care when only the proportion of home deaths is considered. In contrast, neither alternative dominate in CDU space where cost and outcomes are jointly considered, with the optimal strategy depending on threshold values. For example, PEACH minimises ENL when 1=$2,000 and 2=$2,000 (threshold value for dying at home), with a 51.6% chance of PEACH being cost-effective. Conclusion Comparison in CDU space and associated summary measures have distinct advantages to multiple domain comparisons, aiding transparent and robust joint comparison of costs and multiple effects under uncertainty across potential threshold values for effect, better informing net benefit assessment and related reimbursement and research decisions. PMID:25751629
Inter-individual cognitive variability in children with Asperger's syndrome
Gonzalez-Gadea, Maria Luz; Tripicchio, Paula; Rattazzi, Alexia; Baez, Sandra; Marino, Julian; Roca, Maria; Manes, Facundo; Ibanez, Agustin
2014-01-01
Multiple studies have tried to establish the distinctive profile of individuals with Asperger's syndrome (AS). However, recent reports suggest that adults with AS feature heterogeneous cognitive profiles. The present study explores inter-individual variability in children with AS through group comparison and multiple case series analysis. All participants completed an extended battery including measures of fluid and crystallized intelligence, executive functions, theory of mind, and classical neuropsychological tests. Significant group differences were found in theory of mind and other domains related to global information processing. However, the AS group showed high inter-individual variability (both sub- and supra-normal performance) on most cognitive tasks. Furthermore, high fluid intelligence correlated with less general cognitive impairment, high cognitive flexibility, and speed of motor processing. In light of these findings, we propose that children with AS are characterized by a distinct, uneven pattern of cognitive strengths and weaknesses. PMID:25132817
S-Boxes Based on Affine Mapping and Orbit of Power Function
NASA Astrophysics Data System (ADS)
Khan, Mubashar; Azam, Naveed Ahmed
2015-06-01
The demand of data security against computational attacks such as algebraic, differential, linear and interpolation attacks has been increased as a result of rapid advancement in the field of computation. It is, therefore, necessary to develop such cryptosystems which can resist current cryptanalysis and more computational attacks in future. In this paper, we present a multiple S-boxes scheme based on affine mapping and orbit of the power function used in Advanced Encryption Standard (AES). The proposed technique results in 256 different S-boxes named as orbital S-boxes. Rigorous tests and comparisons are performed to analyse the cryptographic strength of each of the orbital S-boxes. Furthermore, gray scale images are encrypted by using multiple orbital S-boxes. Results and simulations show that the encryption strength of the orbital S-boxes against computational attacks is better than that of the existing S-boxes.
Steen, Paul J.; Passino-Reader, Dora R.; Wiley, Michael J.
2006-01-01
As a part of the Great Lakes Regional Aquatic Gap Analysis Project, we evaluated methodologies for modeling associations between fish species and habitat characteristics at a landscape scale. To do this, we created brook trout Salvelinus fontinalis presence and absence models based on four different techniques: multiple linear regression, logistic regression, neural networks, and classification trees. The models were tested in two ways: by application to an independent validation database and cross-validation using the training data, and by visual comparison of statewide distribution maps with historically recorded occurrences from the Michigan Fish Atlas. Although differences in the accuracy of our models were slight, the logistic regression model predicted with the least error, followed by multiple regression, then classification trees, then the neural networks. These models will provide natural resource managers a way to identify habitats requiring protection for the conservation of fish species.
SORL1 variants and risk of late-onset Alzheimer's disease.
Li, Yonghong; Rowland, Charles; Catanese, Joseph; Morris, John; Lovestone, Simon; O'Donovan, Michael C; Goate, Alison; Owen, Michael; Williams, Julie; Grupe, Andrew
2008-02-01
A recent study reported significant association of late-onset Alzheimer's disease (LOAD) with multiple single nucleotide polymorphisms (SNPs) and haplotypes in SORL1, a neuronal sortilin-related receptor protein known to be involved in the trafficking and processing of amyloid precursor protein. Here we attempted to validate this finding in three large, well characterized case-control series. Approximately 2000 samples from the three series were individually genotyped for 12 SNPs, including the 10 reported significant SNPs and 2 that constitute the reported significant haplotypes. A total of 25 allelic and haplotypic association tests were performed. One SNP rs2070045 was marginally replicated in the three sample sets combined (nominal P=0.035); however, this result does not remain significant when accounting for multiple comparisons. Further validation in other sample sets will be required to assess the true effects of SORL1 variants in LOAD.
NASA Astrophysics Data System (ADS)
Ricco, Antonio J.; Parra, Macarena; Niesel, David; Piccini, Matthew; Ly, Diana; McGinnis, Michael; Kudlicki, Andrzej; Hines, John W.; Timucin, Linda; Beasley, Chris; Ricks, Robert; McIntyre, Michael; Friedericks, Charlie; Henschke, Michael; Leung, Ricky; Diaz-Aguado, Millan; Kitts, Christopher; Mas, Ignacio; Rasay, Mike; Agasid, Elwood; Luzzi, Ed; Ronzano, Karolyn; Squires, David; Yost, Bruce
2011-02-01
We designed, built, tested, space-qualified, launched, and collected telemetered data from low Earth orbit from Pharma- Sat, a 5.1-kg free flying "nanosatellite" that supported microbial growth in 48 microfluidic wells, dosed microbes with multiple concentrations of a pharmaceutical agent, and monitored microbial growth and metabolic activity using a dedicated 3-color optical absorbance system at each microwell. The PharmaSat nanosatellite comprised a structure approximately 10 x 10 x 35 cm, including triple-junction solar cells, bidirectional communications, power-generation and energy- storage system, and a sealed payload 1.2-L containment vessel that housed the biological organisms along with the fluidic, optical, thermal, sensor, and electronic subsystems. Growth curves for S. cerevisiae (Brewer's yeast) were obtained for multiple concentrations of the antifungal drug voriconazole in the microgravity conditions of low Earth orbit. Corresponding terrestrial control experiments were conducted for comparison.
Comparison of two underwater acoustic communications techniques for multi-user access
NASA Astrophysics Data System (ADS)
Hursky, Paul; Siderius, T. Martin; Kauaiex Group
2004-05-01
Frequency hopped frequency shift keying (FHFSK) and code division multiple access (CDMA) are two different modulation techniques for multiple users to communicate with a single receiver simultaneously. In July 2003, these two techniques were tested alongside each other in a shallow water coastal environment off the coast of Kauai. A variety of instruments were used to measure the prevailing oceanography, enabling detailed modeling of the channel. The channel was acoustically probed using LFM waveforms and m-sequences as well. We will present the results of demodulating the FHFSK and CDMA waveforms and discuss modeling the channel for the purpose of predicting multi-user communications performance. a)Michael B. Porter, Paul Hursky, Martin Siderius (SAIC), Mohsen Badiey (UD), Jerald Caruthers (USM), William S. Hodgkiss, Kaustubha Raghukumar (SIO), Dan Rouseff, Warren Fox (APL-UW), Christian de Moustier, Brian Calder, Barbara J. Kraft (UNH), Keyko McDonald (SPAWARSSC), Peter Stein, James K. Lewis, and Subramaniam Rajan (SSI).
Examination of association to autism of common genetic variationin genes related to dopamine.
Anderson, B M; Schnetz-Boutaud, N; Bartlett, J; Wright, H H; Abramson, R K; Cuccaro, M L; Gilbert, J R; Pericak-Vance, M A; Haines, J L
2008-12-01
Autism is a severe neurodevelopmental disorder characterized by a triad of complications. Autistic individuals display significant disturbances in language and reciprocal social interactions, combined with repetitive and stereotypic behaviors. Prevalence studies suggest that autism is more common than originally believed, with recent estimates citing a rate of one in 150. Although multiple genetic linkage and association studies have yielded multiple suggestive genes or chromosomal regions, a specific risk locus has yet to be identified and widely confirmed. Because many etiologies have been suggested for this complex syndrome, we hypothesize that one of the difficulties in identifying autism genes is that multiple genetic variants may be required to significantly increase the risk of developing autism. Thus, we took the alternative approach of examining 14 prominent dopamine pathway candidate genes for detailed study by genotyping 28 single nucleotide polymorphisms. Although we did observe a nominally significant association for rs2239535 (P=0.008) on chromosome 20, single-locus analysis did not reveal any results as significant after correction for multiple comparisons. No significant interaction was identified when Multifactor Dimensionality Reduction was employed to test specifically for multilocus effects. Although genome-wide linkage scans in autism have provided support for linkage to various loci along the dopamine pathway, our study does not provide strong evidence of linkage or association to any specific gene or combination of genes within the pathway. These results demonstrate that common genetic variation within the tested genes located within this pathway at most play a minor to moderate role in overall autism pathogenesis.
Many tests of significance: new methods for controlling type I errors.
Keselman, H J; Miller, Charles W; Holland, Burt
2011-12-01
There have been many discussions of how Type I errors should be controlled when many hypotheses are tested (e.g., all possible comparisons of means, correlations, proportions, the coefficients in hierarchical models, etc.). By and large, researchers have adopted familywise (FWER) control, though this practice certainly is not universal. Familywise control is intended to deal with the multiplicity issue of computing many tests of significance, yet such control is conservative--that is, less powerful--compared to per test/hypothesis control. The purpose of our article is to introduce the readership, particularly those readers familiar with issues related to controlling Type I errors when many tests of significance are computed, to newer methods that provide protection from the effects of multiple testing, yet are more powerful than familywise controlling methods. Specifically, we introduce a number of procedures that control the k-FWER. These methods--say, 2-FWER instead of 1-FWER (i.e., FWER)--are equivalent to specifying that the probability of 2 or more false rejections is controlled at .05, whereas FWER controls the probability of any (i.e., 1 or more) false rejections at .05. 2-FWER implicitly tolerates 1 false rejection and makes no explicit attempt to control the probability of its occurrence, unlike FWER, which tolerates no false rejections at all. More generally, k-FWER tolerates k - 1 false rejections, but controls the probability of k or more false rejections at α =.05. We demonstrate with two published data sets how more hypotheses can be rejected with k-FWER methods compared to FWER control.
Common pitfalls in statistical analysis: The perils of multiple testing
Ranganathan, Priya; Pramesh, C. S.; Buyse, Marc
2016-01-01
Multiple testing refers to situations where a dataset is subjected to statistical testing multiple times - either at multiple time-points or through multiple subgroups or for multiple end-points. This amplifies the probability of a false-positive finding. In this article, we look at the consequences of multiple testing and explore various methods to deal with this issue. PMID:27141478
NASA Astrophysics Data System (ADS)
Yu, Fu-Yun; Liu, Yu-Hsin
2005-09-01
The potential value of a multiple-choice question-construction instructional strategy for the support of students’ learning of physics experiments was examined in the study. Forty-two university freshmen participated in the study for a whole semester. A constant comparison method adopted to categorize students’ qualitative data indicated that the influences of multiple-choice question construction were evident in several significant ways (promoting constructive and productive studying habits; reflecting and previewing course-related materials; increasing in-group communication and interaction; breaking passive learning style and habits, etc.), which, worked together, not only enhanced students’ comprehension and retention of the obtained knowledge, but also helped distil a sense of empowerment and learning community within the participants. Analysis with one-group t-tests, using 3 as the expected mean, on quantitative data further found that students’ satisfaction toward past learning experience, and perceptions toward this strategy’s potentials for promoting learning were statistically significant at the 0.0005 level, while learning anxiety was not statistically significant. Suggestions for incorporating question-generation activities within classroom and topics for future studies were rendered.
New approach to CT pixel-based photon dose calculations in heterogeneous media
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wong, J.W.; Henkelman, R.M.
The effects of small cavities on dose in water and the dose in a homogeneous nonunit density medium illustrate that inhomogeneities do not act independently in photon dose perturbation, and serve as two constraints which should be satisfied by approximate methods of computed tomography (CT) pixel-based dose calculations. Current methods at best satisfy only one of the two constraints and show inadequacies in some intermediate geometries. We have developed an approximate method that satisfies both these constraints and treats much of the synergistic effect of multiple inhomogeneities correctly. The method calculates primary and first-scatter doses by first-order ray tracing withmore » the first-scatter contribution augmented by a component of second scatter that behaves like first scatter. Multiple-scatter dose perturbation values extracted from small cavity experiments are used in a function which approximates the small residual multiple-scatter dose. For a wide range of geometries tested, our method agrees very well with measurements. The average deviation is less than 2% with a maximum of 3%. In comparison, calculations based on existing methods can have errors larger than 10%.« less
Fiber sensor network with multipoint sensing using double-pass hybrid LPFG-FBG sensor configuration
NASA Astrophysics Data System (ADS)
Yong, Yun-Thung; Lee, Sheng-Chyan; Rahman, Faidz Abd
2017-03-01
This is a study on double-pass intensity-based hybrid Long Period Fiber Grating (LPFG)and Fiber Bragg Grating (FBG) sensor configuration where a fiber sensor network was constructed with multiple sensing capability. The sensing principle is based on interrogation of intensity changes of the reflected signal from an FBG caused by the LPFG spectral response to the surrounding perturbations. The sensor network developed was tested in monitoring diesel adulteration of up to a distance of 8 km. Kerosene concentration from 0% to 50% was added as adulterant into diesel. The sensitivity of the double-pass hybrid LPFG-FBG sensor over multiple points was>0.21 dB/% (for adulteration range of 0-30%) and >0.45 dB/% from 30% to 50% adulteration. It is found that the sensitivity can drop up to 35% when the fiber length increased from 0 km to 8 km (for the case of adulteration of 0-30%). With the multiple sensing capabilities, normalized FBG's reflected power can be demodulated at the same time for comparison of sensitivity performance across various fiber sensors.
The positive and negative consequences of multiple-choice testing.
Roediger, Henry L; Marsh, Elizabeth J
2005-09-01
Multiple-choice tests are commonly used in educational settings but with unknown effects on students' knowledge. The authors examined the consequences of taking a multiple-choice test on a later general knowledge test in which students were warned not to guess. A large positive testing effect was obtained: Prior testing of facts aided final cued-recall performance. However, prior testing also had negative consequences. Prior reading of a greater number of multiple-choice lures decreased the positive testing effect and increased production of multiple-choice lures as incorrect answers on the final test. Multiple-choice testing may inadvertently lead to the creation of false knowledge.
Voxelwise multivariate analysis of multimodality magnetic resonance imaging.
Naylor, Melissa G; Cardenas, Valerie A; Tosun, Duygu; Schuff, Norbert; Weiner, Michael; Schwartzman, Armin
2014-03-01
Most brain magnetic resonance imaging (MRI) studies concentrate on a single MRI contrast or modality, frequently structural MRI. By performing an integrated analysis of several modalities, such as structural, perfusion-weighted, and diffusion-weighted MRI, new insights may be attained to better understand the underlying processes of brain diseases. We compare two voxelwise approaches: (1) fitting multiple univariate models, one for each outcome and then adjusting for multiple comparisons among the outcomes and (2) fitting a multivariate model. In both cases, adjustment for multiple comparisons is performed over all voxels jointly to account for the search over the brain. The multivariate model is able to account for the multiple comparisons over outcomes without assuming independence because the covariance structure between modalities is estimated. Simulations show that the multivariate approach is more powerful when the outcomes are correlated and, even when the outcomes are independent, the multivariate approach is just as powerful or more powerful when at least two outcomes are dependent on predictors in the model. However, multiple univariate regressions with Bonferroni correction remain a desirable alternative in some circumstances. To illustrate the power of each approach, we analyze a case control study of Alzheimer's disease, in which data from three MRI modalities are available. Copyright © 2013 Wiley Periodicals, Inc.
Analysis of oil-pipeline distribution of multiple products subject to delivery time-windows
NASA Astrophysics Data System (ADS)
Jittamai, Phongchai
This dissertation defines the operational problems of, and develops solution methodologies for, a distribution of multiple products into oil pipeline subject to delivery time-windows constraints. A multiple-product oil pipeline is a pipeline system composing of pipes, pumps, valves and storage facilities used to transport different types of liquids. Typically, products delivered by pipelines are petroleum of different grades moving either from production facilities to refineries or from refineries to distributors. Time-windows, which are generally used in logistics and scheduling areas, are incorporated in this study. The distribution of multiple products into oil pipeline subject to delivery time-windows is modeled as multicommodity network flow structure and mathematically formulated. The main focus of this dissertation is the investigation of operating issues and problem complexity of single-source pipeline problems and also providing solution methodology to compute input schedule that yields minimum total time violation from due delivery time-windows. The problem is proved to be NP-complete. The heuristic approach, a reversed-flow algorithm, is developed based on pipeline flow reversibility to compute input schedule for the pipeline problem. This algorithm is implemented in no longer than O(T·E) time. This dissertation also extends the study to examine some operating attributes and problem complexity of multiple-source pipelines. The multiple-source pipeline problem is also NP-complete. A heuristic algorithm modified from the one used in single-source pipeline problems is introduced. This algorithm can also be implemented in no longer than O(T·E) time. Computational results are presented for both methodologies on randomly generated problem sets. The computational experience indicates that reversed-flow algorithms provide good solutions in comparison with the optimal solutions. Only 25% of the problems tested were more than 30% greater than optimal values and approximately 40% of the tested problems were solved optimally by the algorithms.
Rereading Columbus: Critical Multicultural Analysis of Multiple Historical Storylines
ERIC Educational Resources Information Center
Bothelho, Maria Jose; Young, Sara Lewis-Bernstein; Nappi, Tara
2014-01-01
One prevalent practice of multicultural education is enlisting multiple perspectives for teaching. Oftentimes, these perspectives enter classrooms via digital texts, simulations/scenarios, primary documents, and debates. Children's and young adult literature play a critical role in these comparisons. However, these multiple perspectives are…
Parallel Computing Using Web Servers and "Servlets".
ERIC Educational Resources Information Center
Lo, Alfred; Bloor, Chris; Choi, Y. K.
2000-01-01
Describes parallel computing and presents inexpensive ways to implement a virtual parallel computer with multiple Web servers. Highlights include performance measurement of parallel systems; models for using Java and intranet technology including single server, multiple clients and multiple servers, single client; and a comparison of CGI (common…
Rahimi-Golkhandan, S; Maruff, P; Darby, D; Wilson, P
2012-11-01
Proactive interference (PI) that remains unidentified can confound the assessment of verbal learning, particularly when its effects vary from one population to another. The International Shopping List Task (ISLT) is a new measure that provides multiple forms that can be equated for linguistic factors across cultural groups. The aim of this study was to examine the build-up of PI on two measures of verbal learning-a traditional test of list learning (Rey Auditory Verbal Learning Test, RAVLT) and the ISLT. The sample consisted of 61 healthy adults aged 18-40. Each test had three parallel forms, each recalled three times. Results showed that repeated administration of the ISLT did not result in significant PI effects, unlike the RAVLT. Although these PI effects, observed during short retest intervals, may not be as robust under normal clinical administrations of the tests, the results suggest that the choice of the verbal learning test should be guided by the knowledge of PI effects and the susceptibility of particular patient groups to this effect.
The Testing Methods and Gender Differences in Multiple-Choice Assessment
NASA Astrophysics Data System (ADS)
Ng, Annie W. Y.; Chan, Alan H. S.
2009-10-01
This paper provides a comprehensive review of the multiple-choice assessment in the past two decades for facilitating people to conduct effective testing in various subject areas. It was revealed that a variety of multiple-choice test methods viz. conventional multiple-choice, liberal multiple-choice, elimination testing, confidence marking, probability testing, and order-of-preference scheme are available for use in assessing subjects' knowledge and decision ability. However, the best multiple-choice test method for use has not yet been identified. The review also indicated that the existence of gender differences in multiple-choice task performance might be due to the test area, instruction/scoring condition, and item difficulty.
2012-01-01
Background Mu opioid receptors have previously been shown to be altered in people with affective disorders who died as a result of suicide. We wished to determine whether these changes were more widespread and independent of psychiatric diagnoses. Methods Mu receptor levels were determined using [3 H]DAMGO binding in BA24 from 51 control subjects; 38 people with schizophrenia (12 suicides); 20 people with major depressive disorder (15 suicides); 13 people with bipolar disorder (5 suicides) and 9 people who had no history of psychiatric disorders but who died as a result of suicide. Mu receptor levels were further determined in BA9 and caudate-putamen from 38 people with schizophrenia and 20 control subjects using [3 H]DAMGO binding and, in all three regions, using Western blots. Data was analysed using one-way ANOVAs with Bonferroni’s Multiple Comparison Test or, where data either didn’t approximate to a binomial distribution or the sample size was too small to determine distribution, a Kruskal-Wallis test with Dunn’s Multiple Comparison Test. Results [3 H]DAMGO binding density was lower in people who had died as a result of suicide (p<0.01). People with schizophrenia who had died as a result of suicide had lower binding than control subjects (p<0.001), whilst people with bipolar disorder (non- suicide) had higher levels of binding (p<0.05). [3 H]DAMGO binding densities, but not mu protein levels, were significantly decreased in BA9 from people with schizophrenia who died as a result of suicide (p<0.01). Conclusions Overall these data suggest that mu opioid receptor availability is decreased in the brains of people with schizophrenia who died as a result of suicide, which would be consistent with increased levels of endogenous ligands occupying these receptors. PMID:22925223
NASA Astrophysics Data System (ADS)
Tucker, G. E.; Adams, J. M.; Doty, S. G.; Gasparini, N. M.; Hill, M. C.; Hobley, D. E. J.; Hutton, E.; Istanbulluoglu, E.; Nudurupati, S. S.
2016-12-01
Developing a better understanding of catchment hydrology and geomorphology ideally involves quantitative hypothesis testing. Often one seeks to identify the simplest mathematical and/or computational model that accounts for the essential dynamics in the system of interest. Development of alternative hypotheses involves testing and comparing alternative formulations, but the process of comparison and evaluation is made challenging by the rigid nature of many computational models, which are often built around a single assumed set of equations. Here we review a software framework for two-dimensional computational modeling that facilitates the creation, testing, and comparison of surface-dynamics models. Landlab is essentially a Python-language software library. Its gridding module allows for easy generation of a structured (raster, hex) or unstructured (Voronoi-Delaunay) mesh, with the capability to attach data arrays to particular types of element. Landlab includes functions that implement common numerical operations, such as gradient calculation and summation of fluxes within grid cells. Landlab also includes a collection of process components, which are encapsulated pieces of software that implement a numerical calculation of a particular process. Examples include downslope flow routing over topography, shallow-water hydrodynamics, stream erosion, and sediment transport on hillslopes. Individual components share a common grid and data arrays, and they can be coupled through the use of a simple Python script. We illustrate Landlab's capabilities with a case study of Holocene landscape development in the northeastern US, in which we seek to identify a collection of model components that can account for the formation of a series of incised canyons that have that developed since the Laurentide ice sheet last retreated. We compare sets of model ingredients related to (1) catchment hydrologic response, (2) hillslope evolution, and (3) stream channel and gully incision. The case-study example demonstrates the value of exploring multiple working hypotheses, in the form of multiple alternative model components.
Ritvo, Paul; Myers, Ronald E; Serenity, Mardie; Gupta, Samir; Inadomi, John M; Green, Beverly B; Jerant, Anthony; Tinmouth, Jill; Paszat, Lawrence; Pirbaglou, Meysam; Rabeneck, Linda
2017-08-01
To derive a taxonomy for colorectal cancer screening that advances Randomized Controlled Trials (RCTs) and screening uptake. Detailed publication review, multiple interviews with principal investigators (PIs) and collaboration with PIs as co-authors produced a CRCS intervention taxonomy. Semi-structured interview questions with PIs (Drs. Inadomi, Myers, Green, Gupta, Jerant and Ritvo) yielded details about trial conduct. Interview comparisons led to an iterative process informing serial interviews until a consensus was obtained on final taxonomy structure. These taxonomy headings (Engagement Sponsor, Population Targeted, Alternative Screening Tests, Delivery Methods, and Support for Test Performance (EPADS)) were used to compare studies. Exemplary insights emphasized: 1) direct test delivery to patients; 2) linguistic-ethnic matching of staff to minority subjects; and 3) authorization of navigators to schedule or refer for colonoscopies and/or distribute stool blood tests during screening promotion. PIs of key RCTs (2012-2015) derived a CRCS taxonomy useful in detailed examination of CRCS promotion and design of future RCTs. Copyright © 2017 Elsevier Inc. All rights reserved.
Evaluating Blended and Flipped Instruction in Numerical Methods at Multiple Engineering Schools
ERIC Educational Resources Information Center
Clark, Renee; Kaw, Autar; Lou, Yingyan; Scott, Andrew; Besterfield-Sacre, Mary
2018-01-01
With the literature calling for comparisons among technology-enhanced or active-learning pedagogies, a blended versus flipped instructional comparison was made for numerical methods coursework using three engineering schools with diverse student demographics. This study contributes to needed comparisons of enhanced instructional approaches in STEM…
The Face-Processing Network Is Resilient to Focal Resection of Human Visual Cortex
Jonas, Jacques; Gomez, Jesse; Maillard, Louis; Brissart, Hélène; Hossu, Gabriela; Jacques, Corentin; Loftus, David; Colnat-Coulbois, Sophie; Stigliani, Anthony; Barnett, Michael A.; Grill-Spector, Kalanit; Rossion, Bruno
2016-01-01
Human face perception requires a network of brain regions distributed throughout the occipital and temporal lobes with a right hemisphere advantage. Present theories consider this network as either a processing hierarchy beginning with the inferior occipital gyrus (occipital face area; IOG-faces/OFA) or a multiple-route network with nonhierarchical components. The former predicts that removing IOG-faces/OFA will detrimentally affect downstream stages, whereas the latter does not. We tested this prediction in a human patient (Patient S.P.) requiring removal of the right inferior occipital cortex, including IOG-faces/OFA. We acquired multiple fMRI measurements in Patient S.P. before and after a preplanned surgery and multiple measurements in typical controls, enabling both within-subject/across-session comparisons (Patient S.P. before resection vs Patient S.P. after resection) and between-subject/across-session comparisons (Patient S.P. vs controls). We found that the spatial topology and selectivity of downstream ipsilateral face-selective regions were stable 1 and 8 month(s) after surgery. Additionally, the reliability of distributed patterns of face selectivity in Patient S.P. before versus after resection was not different from across-session reliability in controls. Nevertheless, postoperatively, representations of visual space were typical in dorsal face-selective regions but atypical in ventral face-selective regions and V1 of the resected hemisphere. Diffusion weighted imaging in Patient S.P. and controls identifies white matter tracts connecting retinotopic areas to downstream face-selective regions, which may contribute to the stable and plastic features of the face network in Patient S.P. after surgery. Together, our results support a multiple-route network of face processing with nonhierarchical components and shed light on stable and plastic features of high-level visual cortex following focal brain damage. SIGNIFICANCE STATEMENT Brain networks consist of interconnected functional regions commonly organized in processing hierarchies. Prevailing theories predict that damage to the input of the hierarchy will detrimentally affect later stages. We tested this prediction with multiple brain measurements in a rare human patient requiring surgical removal of the putative input to a network processing faces. Surprisingly, the spatial topology and selectivity of downstream face-selective regions are stable after surgery. Nevertheless, representations of visual space were typical in dorsal face-selective regions but atypical in ventral face-selective regions and V1. White matter connections from outside the face network may support these stable and plastic features. As processing hierarchies are ubiquitous in biological and nonbiological systems, our results have pervasive implications for understanding the construction of resilient networks. PMID:27511014
Kuo, Kevin H M
2017-01-01
The issue of multiple testing, also termed multiplicity, is ubiquitous in studies where multiple hypotheses are tested simultaneously. Genome-wide association study (GWAS), a type of genetic association study that has gained popularity in the past decade, is most susceptible to the issue of multiple testing. Different methodologies have been employed to address the issue of multiple testing in GWAS. The purpose of the review is to examine the methodologies employed in dealing with multiple testing in the context of gene discovery using GWAS in sickle cell disease complications.
2014-01-01
Background It is well established in studies across several countries that tobacco smoking is more prevalent among schizophrenic patients than the general population. Electronic cigarettes are becoming increasingly popular with smokers worldwide. To date there are no large randomized trials of electronic cigarettes in schizophrenic smokers. A well-designed trial is needed to compare efficacy and safety of these products in this special population. Methods/Design Intervention: We have designed a randomized controlled trial investigating the efficacy and safety of electronic cigarette. The trial will take the form of a prospective 12-month randomized clinical study to evaluate smoking reduction, smoking abstinence and adverse events in schizophrenic smokers not intending to quit. We will also monitor quality of life, neurocognitive functioning and measure participants’ perception and satisfaction of the product. Outcome measures: A ≥50% reduction in the number of cigarettes/day from baseline, will be calculated at each study visit (“reducers”). Abstinence from smoking will be calculated at each study visit (“quitters”). Smokers who leave the study protocol before its completion and will carry out the Early Termination Visit or who will not satisfy the criteria of “reducers” and “quitters” will be defined “non responders”. Statistical analysis: The differences of continuous variables between the three groups will be evaluated with the Kruskal-Wallis Test, followed by the Dunn multiple comparison test. The differences between the three groups for normally distributed data will be evaluated with ANOVA test one way, followed by the Newman-Keuls multiple comparison test. The normality of the distribution will be evaluated with the Kolmogorov-Smirnov test. Any correlations between the variables under evaluation will be assessed by Spearman r correlation. To compare qualitative data will be used the Chi-square test. Discussion The main strengths of the SCARIS study are the following: it’s the first large RCT on schizophrenic patient, involving in and outpatient, evaluating the effect of a three-arm study design, and a long term of follow-up (52-weeks). The goal is to propose an effective intervention to reduce the risk of tobacco smoking, as a complementary tool to treat tobacco addiction in schizophrenia. Trial registration ClinicalTrials.gov, NCT01979796. PMID:24655473
NASA Astrophysics Data System (ADS)
Gold, A. U.; Harris, S. E.
2013-12-01
The greenhouse effect comes up in most discussions about climate and is a key concept related to climate change. Existing studies have shown that students and adults alike lack a detailed understanding of this important concept or might hold misconceptions. We studied the effectiveness of different interventions on University-level students' understanding of the greenhouse effect. Introductory level science students were tested for their pre-knowledge of the greenhouse effect using validated multiple-choice questions, short answers and concept sketches. All students participated in a common lesson about the greenhouse effect and were then randomly assigned to one of two lab groups. One group explored an existing simulation about the greenhouse effect (PhET-lesson) and the other group worked with absorption spectra of different greenhouse gases (Data-lesson) to deepen the understanding of the greenhouse effect. All students completed the same assessment including multiple choice, short answers and concept sketches after participation in their lab lesson. 164 students completed all the assessments, 76 completed the PhET lesson and 77 completed the data lesson. 11 students missed the contrasting lesson. In this presentation we show the comparison between the multiple-choice questions, short answer questions and the concept sketches of students. We explore how well each of these assessment types represents student's knowledge. We also identify items that are indicators of the level of understanding of the greenhouse effect as measured in correspondence of student answers to an expert mental model and expert responses. Preliminary data analysis shows that student who produce concept sketch drawings that come close to expert drawings also choose correct multiple-choice answers. However, correct multiple-choice answers are not necessarily an indicator that a student produces an expert-like correlating concept sketch items. Multiple-choice questions that require detailed knowledge of the greenhouse effect (e.g. direction of re-emission of infrared energy from greenhouse gas) are significantly more likely to be answered correctly by students who also produce expert-like concept sketch items than by students who don't include this aspect in their sketch and don't answer the multiple choice questions correctly. This difference is not as apparent for less technical multiple-choice questions (e.g. type of radiation emitted by Sun). Our findings explore the formation of student's mental models throughout different interventions and how well the different assessment techniques used in this study represent the student understanding of the overall concept.
Braun, Patrick; Delgado, Rafael; Drago, Monica; Fanti, Diana; Fleury, Hervé; Izopet, Jacques; Lombardi, Alessandra; Marcos, MaAngeles; Sauné, Karine; O'Shea, Siobhan; Pérez-Rivilla, Alfredo; Ramble, John; Trimoulet, Pascale; Vila, Jordi; Whittaker, Duncan; Artus, Alain; Rhodes, Daniel
2017-10-01
Hepatitis B viral load testing is essential to treatment and monitoring decisions in patients with chronic Hepatitis B. Beckman Coulter has developed the VERIS HBV Assay (Veris) for use on the fully automated DxN VERIS Molecular Diagnostics System. 1 OBJECTIVES: To evaluate the clinical performance of the Veris HBV Assay at multiple EU laboratories STUDY DESIGN: Method comparison was performed with a total of 344 plasma specimens from HBV infected patients tested with Veris and COBAS ® TaqMan ® HBV Test (Cobas), 207 specimens tested with Veris and RealTime HBV Assay (RealTime), 86 specimens tested with Veris and VERSANT ® HBV Assay (Versant), and 74 specimens tested with Veris and artus ® HBV RG PCR kit (artus). Bland-Altman analysis showed average bias of -0.46 log 10 IU/mL between Veris and Cobas, -0.46 log 10 IU/mL between Veris and RealTime, -0.36 log 10 IU/mL between Veris and Versant, and -0.12 log 10 IU/mL between Veris and artus. Bias was consistent across the assay range. Patient monitoring results using Veris demonstrated similar viral load trends over time to Cobas, RealTime, and artus. The VERIS HBV Assay demonstrated comparable clinical performance, with varying degrees of negative bias, compared to other currently marketed assays for HBV DNA monitoring. This negative bias should be taken into consideration if switching monitoring methods to Veris. Copyright © 2017 Elsevier B.V. All rights reserved.
Konietschke, Frank; Libiger, Ondrej; Hothorn, Ludwig A
2012-01-01
Statistical association between a single nucleotide polymorphism (SNP) genotype and a quantitative trait in genome-wide association studies is usually assessed using a linear regression model, or, in the case of non-normally distributed trait values, using the Kruskal-Wallis test. While linear regression models assume an additive mode of inheritance via equi-distant genotype scores, Kruskal-Wallis test merely tests global differences in trait values associated with the three genotype groups. Both approaches thus exhibit suboptimal power when the underlying inheritance mode is dominant or recessive. Furthermore, these tests do not perform well in the common situations when only a few trait values are available in a rare genotype category (disbalance), or when the values associated with the three genotype categories exhibit unequal variance (variance heterogeneity). We propose a maximum test based on Marcus-type multiple contrast test for relative effect sizes. This test allows model-specific testing of either dominant, additive or recessive mode of inheritance, and it is robust against variance heterogeneity. We show how to obtain mode-specific simultaneous confidence intervals for the relative effect sizes to aid in interpreting the biological relevance of the results. Further, we discuss the use of a related all-pairwise comparisons contrast test with range preserving confidence intervals as an alternative to Kruskal-Wallis heterogeneity test. We applied the proposed maximum test to the Bogalusa Heart Study dataset, and gained a remarkable increase in the power to detect association, particularly for rare genotypes. Our simulation study also demonstrated that the proposed non-parametric tests control family-wise error rate in the presence of non-normality and variance heterogeneity contrary to the standard parametric approaches. We provide a publicly available R library nparcomp that can be used to estimate simultaneous confidence intervals or compatible multiplicity-adjusted p-values associated with the proposed maximum test.
Jaipuria, Jiten; Suryavanshi, Manav; Sen, Tridib K
2016-12-01
To assess the reliability of the Guy's Stone Score, the Seoul National University Renal Stone Complexity (S-ReSC) score and the S.T.O.N.E. scores in percutaneous nephrolithotomy (PCNL), and assess their utility in discriminating outcomes [stone free rate (SFR), complications, need for multiple PCNL sessions, and auxiliary procedures] valid across parameters of experience of surgeon, independence from surgical approach, and variations in institution-specific instrumentation. A prospectively maintained database of two tertiary institutions was analysed (606 cases). Institutes differed in instrumentation, while the overall surgical team comprised: two trainees (experience <100 cases), two junior consultants (experience 100-200 cases), and two senior surgeons (experience >1000 cases). Scores were assigned and re-assigned after 4 months by one trainee and an expert surgeon. Inter-rater and test-retest agreement were analysed by Cohen's κ and intraclass correlation coefficient. Multivariate logistic regression models were created adjusting outcomes for the institution, comorbidity, Amplatz size, access tract location, the number of punctures, the experience level of the surgeon, and individual scoring system, and receiver operating curves were analysed for comparison. Despite some areas of inconsistencies, individually all scores had excellent inter-rater and test-retest concordance. On multivariable analyses, while the experience of the surgeon and surgical approach characteristics (such as access tract location, Amplatz size, and number of punctures) remained independently associated with different outcomes in varying combinations, calculus complexity scores were found consistently to be independently associated with all outcomes. The S-ReSC score had a superior association with SFR, the need for multiple PCNL sessions, and auxiliary procedures. Individually all scoring systems performed well. On cross comparison, the S-ReSC score consistently emerged to be more superiorly associated with all outcomes, signifying the importance of the distributional complexity of the calculus (which also indirectly amalgamates the influence of stone number, size, and anatomical location) in discriminating outcomes. Our study proves the utility of scoring systems in prognosticating multiple outcomes and also clarifies important aspects of their practical application including future roles such as benchmarking, audit, training, and objective assessment of surgical technique modifications. © 2016 The Authors BJU International © 2016 BJU International Published by John Wiley & Sons Ltd.
Evaluating the diagnostic specificity of the Munich Personality Test dimensions in major depression.
Sakado, K; Sato, T; Uehara, T; Sato, S; Sakado, M; Kumagai, K
1997-05-01
This study explored the diagnostic specificity of the Munich Personality Test (MPT) in major depression, comparing its scores between patients with major depression, patients with panic disorder and control subjects. One of the 6 dimensions of the MPT, Rigidity, had been developed based on Tellenbach's description of depressive personality, and it was expected that especially this personality dimension would demonstrate a good facility for describing a specific personality feature of major depression. Comparisons were made in 2 ways: ignoring the effects of current depression and anxiety on the personality scorings; and partialling out these effects. Results of the 2 analyses differed radically. Scores on Rigidity and isolation Tendency were significantly different between groups, even after the effects of current depression and anxiety were partialled out. The multiple comparison procedure revealed that the depressive patients were differentiated from both the panic patients and the controls only in the dimension of Rigidity. The results of this study suggest that the Rigidity dimension of MPT may have a strong capability for describing the specific personality feature of depressive patients, and that the MPT may be quite useful for studies, particularly prospective ones, investigating premorbid personality of depression.
Implementation and Validation of an Impedance Eduction Technique
NASA Technical Reports Server (NTRS)
Watson, Willie R.; Jones, Michael G.; Gerhold, Carl H.
2011-01-01
Implementation of a pressure gradient method of impedance eduction in two NASA Langley flow ducts is described. The Grazing Flow Impedance Tube only supports plane-wave sources, while the Curved Duct Test Rig supports sources that contain higher-order modes. Multiple exercises are used to validate this new impedance eduction method. First, synthesized data for a hard wall insert and a conventional liner mounted in the Grazing Flow Impedance Tube are used as input to the two impedance eduction methods, the pressure gradient method and a previously validated wall pressure method. Comparisons between the two results are excellent. Next, data measured in the Grazing Flow Impedance Tube are used as input to both methods. Results from the two methods compare quite favorably for sufficiently low Mach numbers but this comparison degrades at Mach 0.5, especially when the hard wall insert is used. Finally, data measured with a hard wall insert mounted in the Curved Duct Test Rig are used as input to the pressure gradient method. Significant deviation from the known solution is observed, which is believed to be largely due to 3-D effects in this flow duct. Potential solutions to this issue are currently being explored.
Pham-The, Hai; Casañola-Martin, Gerardo; Garrigues, Teresa; Bermejo, Marival; González-Álvarez, Isabel; Nguyen-Hai, Nam; Cabrera-Pérez, Miguel Ángel; Le-Thi-Thu, Huong
2016-02-01
In many absorption, distribution, metabolism, and excretion (ADME) modeling problems, imbalanced data could negatively affect classification performance of machine learning algorithms. Solutions for handling imbalanced dataset have been proposed, but their application for ADME modeling tasks is underexplored. In this paper, various strategies including cost-sensitive learning and resampling methods were studied to tackle the moderate imbalance problem of a large Caco-2 cell permeability database. Simple physicochemical molecular descriptors were utilized for data modeling. Support vector machine classifiers were constructed and compared using multiple comparison tests. Results showed that the models developed on the basis of resampling strategies displayed better performance than the cost-sensitive classification models, especially in the case of oversampling data where misclassification rates for minority class have values of 0.11 and 0.14 for training and test set, respectively. A consensus model with enhanced applicability domain was subsequently constructed and showed improved performance. This model was used to predict a set of randomly selected high-permeability reference drugs according to the biopharmaceutics classification system. Overall, this study provides a comparison of numerous rebalancing strategies and displays the effectiveness of oversampling methods to deal with imbalanced permeability data problems.
Performance comparison of Islamic and commercial banks in Malaysia
NASA Astrophysics Data System (ADS)
Azizud-din, Azimah; Hussin, Siti Aida Sheikh; Zahid, Zalina
2016-10-01
The steady growth in the size and increase in the number of Islamic banks show that the Islamic banking system is considered as an alternative to the conventional banking system. Due to this, comparisons in term of performance measurements and evaluation of the financial health for both type of banks are essential. The main purpose of this study is to analyse the differences between Islamic and commercial banks performance. Five years secondary data were collected from the annual report for each bank. Return on Asset ratio is chosen as the dependent variable, while capital adequacy, asset quality, management quality, earning, liquidity and sensitivity to market risk (CAMELS) are the independent variables. Descriptive analyses were done to understand the data. The independent t-test and Mann Whitney test show the differences of Islamic and commercial banks based on the financial variables. The stepwise and hierarchical multiple regressions were used to determine the factor that affects profitability performance of banks. Results show that Islamic banks are better in term of profitability performance, earning power performance, liquidity performance and sensitive to market risk. The factors that affect profitability performance are capital adequacy, earning power and liquidity variable.
Boehm, A B; Griffith, J; McGee, C; Edge, T A; Solo-Gabriele, H M; Whitman, R; Cao, Y; Getrich, M; Jay, J A; Ferguson, D; Goodwin, K D; Lee, C M; Madison, M; Weisberg, S B
2009-11-01
The absence of standardized methods for quantifying faecal indicator bacteria (FIB) in sand hinders comparison of results across studies. The purpose of the study was to compare methods for extraction of faecal bacteria from sands and recommend a standardized extraction technique. Twenty-two methods of extracting enterococci and Escherichia coli from sand were evaluated, including multiple permutations of hand shaking, mechanical shaking, blending, sonication, number of rinses, settling time, eluant-to-sand ratio, eluant composition, prefiltration and type of decantation. Tests were performed on sands from California, Florida and Lake Michigan. Most extraction parameters did not significantly affect bacterial enumeration. anova revealed significant effects of eluant composition and blending; with both sodium metaphosphate buffer and blending producing reduced counts. The simplest extraction method that produced the highest FIB recoveries consisted of 2 min of hand shaking in phosphate-buffered saline or deionized water, a 30-s settling time, one-rinse step and a 10 : 1 eluant volume to sand weight ratio. This result was consistent across the sand compositions tested in this study but could vary for other sand types. Method standardization will improve the understanding of how sands affect surface water quality.
Taggart, Tamara; Taboada, Arianna; Stein, Judith A; Milburn, Norweeta G; Gere, David; Lightfoot, Alexandra F
2016-07-01
AMP! (Arts-based, Multiple component, Peer-education) is an HIV intervention developed for high school adolescents. AMP! uses interactive theater-based scenarios developed by trained college undergraduates to deliver messages addressing HIV/STI prevention strategies, healthy relationships, and stigma reduction towards people living with HIV/AIDS. We used a pre-test/post-test, control group study design to simultaneously assess intervention effect on ninth grade students in an urban county in California (N = 159) and a suburban county in North Carolina (N = 317). In each location, the control group received standard health education curricula delivered by teachers; the intervention group received AMP! in addition to standard health education curricula. Structural equation modeling was used to determine intervention effects. The post-test sample was 46 % male, 90 % self-identified as heterosexual, 32 % reported receiving free or reduced lunch, and 49 % White. Structural models indicated that participation in AMP! predicted higher scores on HIV knowledge (p = 0.05), HIV awareness (p = 0.01), and HIV attitudes (p = 0.05) at the post-test. Latent means comparison analyses revealed post-test scores were significantly higher than pre-test scores on HIV knowledge (p = 0.001), HIV awareness (p = 0.001), and HIV attitudes (p = 0.001). Further analyses indicated that scores rose for both groups, but the post-test scores of intervention participants were significantly higher than controls (HIV knowledge (p = 0.01), HIV awareness (p = 0.01), and HIV attitudes (p = 0.05)). Thus, AMP!'s theater-based approach shows promise for addressing multiple adolescent risk factors and attitudes concerning HIV in school settings.
Does rational selection of training and test sets improve the outcome of QSAR modeling?
Martin, Todd M; Harten, Paul; Young, Douglas M; Muratov, Eugene N; Golbraikh, Alexander; Zhu, Hao; Tropsha, Alexander
2012-10-22
Prior to using a quantitative structure activity relationship (QSAR) model for external predictions, its predictive power should be established and validated. In the absence of a true external data set, the best way to validate the predictive ability of a model is to perform its statistical external validation. In statistical external validation, the overall data set is divided into training and test sets. Commonly, this splitting is performed using random division. Rational splitting methods can divide data sets into training and test sets in an intelligent fashion. The purpose of this study was to determine whether rational division methods lead to more predictive models compared to random division. A special data splitting procedure was used to facilitate the comparison between random and rational division methods. For each toxicity end point, the overall data set was divided into a modeling set (80% of the overall set) and an external evaluation set (20% of the overall set) using random division. The modeling set was then subdivided into a training set (80% of the modeling set) and a test set (20% of the modeling set) using rational division methods and by using random division. The Kennard-Stone, minimal test set dissimilarity, and sphere exclusion algorithms were used as the rational division methods. The hierarchical clustering, random forest, and k-nearest neighbor (kNN) methods were used to develop QSAR models based on the training sets. For kNN QSAR, multiple training and test sets were generated, and multiple QSAR models were built. The results of this study indicate that models based on rational division methods generate better statistical results for the test sets than models based on random division, but the predictive power of both types of models are comparable.
Wu, Xia; Li, Juan; Ayutyanont, Napatkamon; Protas, Hillary; Jagust, William; Fleisher, Adam; Reiman, Eric; Yao, Li; Chen, Kewei
2013-01-01
Given a single index, the receiver operational characteristic (ROC) curve analysis is routinely utilized for characterizing performances in distinguishing two conditions/groups in terms of sensitivity and specificity. Given the availability of multiple data sources (referred to as multi-indices), such as multimodal neuroimaging data sets, cognitive tests, and clinical ratings and genomic data in Alzheimer’s disease (AD) studies, the single-index-based ROC underutilizes all available information. For a long time, a number of algorithmic/analytic approaches combining multiple indices have been widely used to simultaneously incorporate multiple sources. In this study, we propose an alternative for combining multiple indices using logical operations, such as “AND,” “OR,” and “at least n” (where n is an integer), to construct multivariate ROC (multiV-ROC) and characterize the sensitivity and specificity statistically associated with the use of multiple indices. With and without the “leave-one-out” cross-validation, we used two data sets from AD studies to showcase the potentially increased sensitivity/specificity of the multiV-ROC in comparison to the single-index ROC and linear discriminant analysis (an analytic way of combining multi-indices). We conclude that, for the data sets we investigated, the proposed multiV-ROC approach is capable of providing a natural and practical alternative with improved classification accuracy as compared to univariate ROC and linear discriminant analysis.
Wu, Xia; Li, Juan; Ayutyanont, Napatkamon; Protas, Hillary; Jagust, William; Fleisher, Adam; Reiman, Eric; Yao, Li; Chen, Kewei
2014-01-01
Given a single index, the receiver operational characteristic (ROC) curve analysis is routinely utilized for characterizing performances in distinguishing two conditions/groups in terms of sensitivity and specificity. Given the availability of multiple data sources (referred to as multi-indices), such as multimodal neuroimaging data sets, cognitive tests, and clinical ratings and genomic data in Alzheimer’s disease (AD) studies, the single-index-based ROC underutilizes all available information. For a long time, a number of algorithmic/analytic approaches combining multiple indices have been widely used to simultaneously incorporate multiple sources. In this study, we propose an alternative for combining multiple indices using logical operations, such as “AND,” “OR,” and “at least n” (where n is an integer), to construct multivariate ROC (multiV-ROC) and characterize the sensitivity and specificity statistically associated with the use of multiple indices. With and without the “leave-one-out” cross-validation, we used two data sets from AD studies to showcase the potentially increased sensitivity/specificity of the multiV-ROC in comparison to the single-index ROC and linear discriminant analysis (an analytic way of combining multi-indices). We conclude that, for the data sets we investigated, the proposed multiV-ROC approach is capable of providing a natural and practical alternative with improved classification accuracy as compared to univariate ROC and linear discriminant analysis. PMID:23702553
Kaplan, Mark S.; Huguet, Nathalie; Caetano, Raul; Giesbrecht, Norman; Kerr, William C.; McFarland, Bentson H.
2016-01-01
Background The primary objective of this gender-stratified study was to assess the rate of heavy alcohol use among suicide decedents relative to a nonsuicide comparison group during the 2008-09 economic crisis. Methods The National Violent Death Reporting System and the Behavioral Risk Factor Surveillance System were analyzed by gender-stratified multiple logistic regression to test whether change in acute intoxication (blood alcohol content ≥ 0.08 g/dl) before (2005-07), during (2008-09), and after (2010-11) the Great Recession mirrored change in heavy alcohol use in a living sample. Results Among men, suicide decedents experienced a significantly greater increase (+8%) in heavy alcohol use at the onset of the recession (AOR=1.15, 95% confidence interval [CI]=1.10-1.20) (relative to the pre-recession period) than did men in a nonsuicide comparison group (−2%). Among women, changes in rates of heavy alcohol use were similar in the suicide and nonsuicide comparison groups at the onset and after the recession. Conclusions Acute alcohol use contributed to suicide among men during the recent economic downturn. Among women who died by suicide, acute alcohol use mirrored consumption in the general population. Women may show resilience (or men, vulnerability) to deleterious interaction of alcohol with financial distress. PMID:27187543
Factors contributing to airborne particle dispersal in the operating room.
Noguchi, Chieko; Koseki, Hironobu; Horiuchi, Hidehiko; Yonekura, Akihiko; Tomita, Masato; Higuchi, Takashi; Sunagawa, Shinya; Osaki, Makoto
2017-07-06
Surgical-site infections due to intraoperative contamination are chiefly ascribable to airborne particles carrying microorganisms. The purpose of this study is to identify the actions that increase the number of airborne particles in the operating room. Two surgeons and two surgical nurses performed three patterns of physical movements to mimic intraoperative actions, such as preparing the instrument table, gowning and donning/doffing gloves, and preparing for total knee arthroplasty. The generation and behavior of airborne particles were filmed using a fine particle visualization system, and the number of airborne particles in 2.83 m 3 of air was counted using a laser particle counter. Each action was repeated five times, and the particle measurements were evaluated through one-way analysis of variance multiple comparison tests followed by Tukey-Kramer and Bonferroni-Dunn multiple comparison tests for post hoc analysis. Statistical significance was defined as a P value ≤ .01. A large number of airborne particles were observed while unfolding the surgical gown, removing gloves, and putting the arms through the sleeves of the gown. Although numerous airborne particles were observed while applying the stockinet and putting on large drapes for preparation of total knee arthroplasty, fewer particles (0.3-2.0 μm in size) were detected at the level of the operating table under laminar airflow compared to actions performed in a non-ventilated preoperative room (P < .01). The results of this study suggest that surgical staff should avoid unnecessary actions that produce a large number of airborne particles near a sterile area and that laminar airflow has the potential to reduce the incidence of bacterial contamination.
Pulmonary function parameters and use of bronchodilators in patients with cystic fibrosis*
Muramatu, Lucia Harumi; Stirbulov, Roberto; Forte, Wilma Carvalho Neves
2013-01-01
OBJECTIVE: To analyze pulmonary function parameters and pharmacodynamic response to a bronchodilator, as well as the prescription of bronchodilators, in cystic fibrosis (CF) patients. METHODS: This was a retrospective cohort study involving patients 6-18 years of age, diagnosed with CF, and followed at a referral center between 2008 and 2010. We evaluated only those patients who were able to perform pulmonary function tests (PFTs). We analyzed FVC, FEV1, and FEF25-75%, expressed as percentages of the predicted values, prior to and after bronchodilator tests (pre-BD and post-BD, respectively), in 312 PFTs. Repeated measures ANOVA and multiple comparisons were used. RESULTS: The study included 56 patients, divided into two groups: those whose PFT results spanned the 2008-2010 period (n = 37); and those whose PFT results spanned only the 2009-2010 period (n = 19). In the 2008-2010 group, there were significant reductions in post-BD FEV1 between 2008 and 2010 (p = 0.028) and between 2009 and 2010 (p = 0.036), as was also the case for pre-BD and post-BD FEF25 75% in all multiple comparisons (2008 vs. 2009; 2008 vs. 2010; and 2009 vs. 2010). In the 2009-2010 group, there were no significant differences between any of the years for any of the variables studied. Among the 312 PFTs, significant responses to the bronchodilator occurred in only 24 (7.7%), all of which were from patients for whom no bronchodilator had been prescribed during the study period. CONCLUSIONS: In the CF patients studied, there was loss of pulmonary function, indicating progressive lung disease, over time. The changes were greater for FEF25-75% than for the other variables, which suggests the initial involvement of small airways. PMID:23503485
Amirkhanian, Yuri A; Kelly, Jeffrey A; Takacs, Judit; McAuliffe, Timothy L; Kuznetsova, Anna V; Toth, Tamas P; Mocsonaki, Laszlo; DiFranceisco, Wayne J; Meylakhs, Anastasia
2015-03-13
To test a novel social network HIV risk-reduction intervention for MSM in Russia and Hungary, where same-sex behavior is stigmatized and men may best be reached through their social network connections. A two-arm trial with 18 sociocentric networks of MSM randomized to the social network intervention or standard HIV/STD testing/counseling. St. Petersburg, Russia and Budapest, Hungary. Eighteen 'seeds' from community venues invited the participation of their MSM friends who, in turn, invited their own MSM friends into the study, a process that continued outward until eighteen three-ring sociocentric networks (mean size = 35 members, n = 626) were recruited. Empirically identified network leaders were trained and guided to convey HIV prevention advice to other network members. Changes in sexual behavior from baseline to 3-month and 12-month follow-up, with composite HIV/STD incidence, measured at 12 months to corroborate behavior changes. There were significant reductions between baseline, first follow-up, and second follow-up in the intervention versus comparison arm for proportion of men engaging in any unprotected anal intercourse (UAI) (P = 0.04); UAI with a nonmain partner (P = 0.04); and UAI with multiple partners (P = 0.002). The mean percentage of unprotected anal intercourse acts significantly declined (P = 0.001), as well as the mean number of UAI acts among men who initially had multiple partners (P = 0.05). Biological HIV/STD incidence was 15% in comparison condition networks and 9% in intervention condition networks. Even where same-sex behavior is stigmatized, it is possible to reach MSM and deliver HIV prevention through their social networks.
Siega-Riz, Anna Maria; Haugen, Margaretha; Meltzer, Helle M; Von Holle, Ann; Hamer, Robert; Torgersen, Leila; Knopf-Berg, Cecilie; Reichborn-Kjennerud, Ted; Bulik, Cynthia M
2008-05-01
Little is known concerning the dietary habits during pregnancy of women with eating disorders that may lie in the causal pathway of adverse birth outcomes. We examined the nutrient and food group intakes of women with bulimia nervosa and binge-eating disorder during pregnancy and compared these with intakes of women with no eating disorders. Data on 30,040 mother-child pairs from the prospective Norwegian Mother and Child Cohort Study were used in cross-sectional analyses. Dietary information was collected by using a food-frequency questionnaire during the first half of pregnancy. Statistical testing by eating disorder categories with the non-eating-disorder category as the referent group was conducted by using log means adjusted for confounding and multiple comparisons. Food group differences were analyzed by using a Wilcoxon's two-sided normal approximation test that was also adjusted for multiple comparisons. Women with binge-eating disorder before and during pregnancy had higher intakes of total energy, total fat, monounsaturated fat, and saturated fat, and lower intakes of folate, potassium, and vitamin C than the referent (P < 0.02). Women with incident binge-eating disorder during pregnancy had higher intakes of total energy and saturated fat than the referent (P = 0.01). Several differences emerged in food group consumption between women with and without eating disorders, including intakes of artificial sweeteners, sweets, juice, fruit, and fats. Women with bulimia nervosa before and during pregnancy and those with binge-eating disorder before pregnancy exhibit dietary patterns that differ from those in women without eating disorders, that are reflective of their symptomatology, and that may influence pregnancy outcomes.
Amirkhanian, Yuri A.; Kelly, Jeffrey A.; Takacs, Judit; McAuliffe, Timothy L.; Kuznetsova, Anna V.; Toth, Tamas P.; Mocsonaki, Laszlo; DiFranceisco, Wayne J.; Meylakhs, Anastasia
2015-01-01
Objective To test a novel social network HIV risk reduction intervention for MSM in Russia and Hungary, where same-sex behavior is stigmatized and men may best be reached through their social network connections. Design A 2-arm trial with 18 sociocentric networks of MSM randomized to the social network intervention or standard HIV/STD testing/counseling. Setting St. Petersburg, Russia and Budapest, Hungary. Participants 18 “seeds” from community venues invited the participation of their MSM friends who, in turn, invited their own MSM friends into the study, a process that continued outward until eighteen 3-ring sociocentric networks (mean size=35 members, n=626) were recruited. Intervention Empirically-identified network leaders were trained and guided to convey HIV prevention advice to other network members. Main Outcome and Measures Changes in sexual behavior from baseline to 3- and 12-month followup, with composite HIV/STD incidence measured at 12-months to corroborate behavior changes. Results There were significant reductions between baseline, first followup, and second followup in the intervention versus comparison arm for proportion of men engaging in any unprotected anal intercourse (P=.04); UAI with a nonmain partner (P=.04); and UAI with multiple partners (P=.002). The mean percentage of unprotected AI acts significantly declined (P=.001), as well as the mean number of UAI acts among men who initially had multiple partners (P=.05). Biological HIV/STD incidence was 15% in comparison condition networks and 9% in intervention condition networks. Conclusions Even where same-sex behavior is stigmatized, it is possible to reach MSM and deliver HIV prevention through their social networks. PMID:25565495
Dunster, Kimble R; Davies, Mark W; Fraser, John F
2006-01-01
Background The loss of perfluorocarbon (PFC) vapour in the expired gases during partial liquid ventilation should be minimized both to prevent perfluorocarbon vapour entering the atmosphere and to re-use the recovered PFC liquid. Using a substantially modified design of our previously described condenser, we aimed to determine how much perfluorocarbon liquid could be recovered from gases containing PFC and water vapour, at concentrations found during partial liquid ventilation, and to determine if the amount recovered differed with background flow rate (at flow rates suitable for use in neonates). Methods The expiratory line of a standard ventilator circuit set-up was mimicked, with the addition of two condensers. Perfluorocarbon (30 mL of FC-77) and water vapour, at concentrations found during partial liquid ventilation, were passed through the circuit at a number of flow rates and the percentage recovery of the liquids measured. Results From 14.2 mL (47%) to 27.3 mL (91%) of the infused 30 mL of FC-77 was recovered at the flow rates studied. Significantly higher FC-77 recovery was obtained at lower flow rates (ANOVA with Bonferroni's multiple comparison test, p < 0.0001). As a percentage of the theoretical maximum recovery, 64 to 95% of the FC-77 was recovered. Statistically significantly less FC-77 was recovered at 5 Lmin-1 (ANOVA with Bonferroni's multiple comparison test, p < 0.0001). Amounts of perfluorocarbon vapour recovered were 47%, 50%, 81% and 91% at flow rates of 10, 5, 2 and 1 Lmin-1, respectively. Conclusion Using two condensers in series 47% to 91% of perfluorocarbon liquid can be recovered, from gases containing perfluorocarbon and water vapour, at concentrations found during partial liquid ventilation. PMID:16457722